Proceedings of the Fifth AWWARF / JWWA Water System Seismic Conference August 15 – 17, 2007
Proceedings of the Fifth Water System Seismic Conference
August 15-17, 2007
East Bay Municipal Utility District
Oakland, California
Co-Sponsored by
American Water Works Association Research Foundation
East Bay Municipal Utility District
Japan Water Works Association
Taiwan Water Works Association
Multidisciplinary Center for Earthquake Engineering Research
American Water Works Association Research Foundation
All rights reserved.
Printed in the United States of America
Copies of this report may be obtained from:
American Water Works Research Foundation 6666 West Quincy Avenue Denver, CO 80235-3098 Telephone: 303-347-6100 Fax: 303-730-0851 Email: [email protected] Web site: www.awwarf.org
Table of Contents
Overview...... 1 Participants List ...... 5 Agenda ...... 17
KEYNOTE SPEECH Prof. Yosihiko Hosoi Tottori University, Japan, "Earthquake Countermeasures for Water Supply Systems from Standpoint of Residents" ...... Prof. Thomas O’Rourke Cornell University, US "Recent Advances in Research and Practice for the Seismic Performance of Water Supplies" ...... 25
SESSION 1 – SEISMIC MITIGATION MEASURES Mr. Masaru Oneda Tokyo Metropolitan Waterworks Bureau, Tokyo, Japan “Seismic Measures and its Emergency Plan of Tokyo Waterworks Bureau” ...... 31 Ms. Chandrika Winston Memphis Light Gas and Water, Memphis, TN, US “Seismic Performance Objectives for MLGW Water Facilities Past, Present and Future” ....43 Mr. Shigeru Hataya Chiba Perfectural Waterworks Bureau, Chiba Perfecture, Japan “Anti-earthquake Measures of Chiba Perfectural Waterworks Bureau” ...... 55 Ms. Elizabeth Bialek and Mr. Atta Yiadom, East Bay Municipal Utility District, Oakland, CA, US “A New Solution for a Hydraulic Fill Dam – The Case of San Pablo Dam”...... 65 Mr. Nobuhiro Hasegawa JFE Engineering Corporation (Japanese Water Steel Pipes Association), Yokohama, Japan “Manual for Improvement of Over Aged Reservoirs with Steel Plate” ...... 77
SESSION 2 – SEISMIC MEASURES FOR PIPELINES
Mr. Hiroaki Miyazaki Osaka Municipal Waterworks Bureau, Osaka, Japan
“Seismic Damage Estimation of Distribution Pipes” ...... 91 Mr. David Tsztoo East Bay Municipal Utility District, Oakland, CA, US “Challenges of the Claremont Tunnel Seismic Upgrade Project” ...... 103 Mr. Yukio Mabuchi Waterworks & Sewerage Bureau, City of Nagoya, Japan “Earthquake Countermeasures in Nagoya” ...... 115 Mr. Ahmed Nisar MMI Engineering, Oakland, CA, US “Fault Crossing Design of a Critical Large Diameter Pipeline” ...... 127
SESSION 3 – OUTREACH, EDUCATION AND COMMUNICATIONS FOR EARTHQUAKE RISKS
Mr. Kazuhiko Mizuguchi Kobe Municipal Waterworks, Kobe, Japan “Seismic Practices and Strategies of Public Relations in Kobe City”...... 139 Prof. Adam Rose University of Southern California, US “Regional Economic Analysis of Earthquake Losses, Mitigation and Resilience”...... 151 Dr. Nagahisa Hirayama Disaster Reduction and Human Renovation Institute, Kobe, Japan “Participatory Planning in Development of Comprehensive Crisis Management Plan for Water Supply Authorities”...... 167 Mr. Luke Cheng San Francisco Public Utilities Commission, San Francisco, CA, US “Seismic Aspects of the SFPUC Water System Improvement Program” ...... 179 Mr. Shinji Nakayasu Hanshin Water Supply Authority, Hyogo, Japan “Information Provision to Residents on Construction of Regulating Reservoir at Landslide Site Caused by an Earthquake”...... 191
SESSION 4 – SEISMIC SYSTEM EVALUATIONS
Mr. Kazutomo Nakamura Japan Water Works Association, Tokyo, Japan “A Case Study on How PIs Should Be Applied in Evaluating Seismic Performance Along with the Water Works Guidelines”...... 203
Mr. Yasuhiko Sato Japan Water Research Center, Tokyo, Japan “Function Diagnosis Method to Improve Earthquake Resistance of Water Supply Facilities” ...... 215 Mr. Noboru Murakami Hachinohe Water Supply Authority, Hachinohe, Japan “Nejo Purification Plant Water System Facilities Today”...... 227 Mr. Hidehiko Aihara Yokohama City Waterworks Bureau, Japan “The Quakeproof Diagnosis of Waterworks Facilities in Yokohama City”...... 241 Ms. Crystal Yezman Santa Clara Valley Water District, San Jose, CA, US “Santa Clara Valley Water District Reliability Program, Implementing Improvements for Seismic Response”...... 255
SESSION 5 – EARTHQUAKE STUDIES AND EVALUATIONS
Prof. Masanobu Shinozuka University of California, Irvine, US “A Sensor Network for Real-Time Damage Location and Assessment” ...... 269 Mr. Munetaka Abe Japan Water Works Association, Tokyo, Japan “Damages to Water Supply Facilities by the Noto Peninsula Earthquake in 2007 and Restoration Works and Issues” ...... 277 Mr. Jianping Hu Los Angeles Department of Water and Power, Los Angeles, CA, US “Seismic Performance Evaluation of LADWP Water Supply System Using GIRAFFE”....289 Dr. Gee-Yu Liu National Center for Research on Earthquake Engineering, TAIWAN “Seismic Repair Rate Analysis and Risk Assessment of Water Pipelines”...... 303 Mr. Kuniaki Nakamura Fukuoka City Waterworks Bureau, Fukuoka, Japan “Emergency Measures - A Study of the Fukuoka West Offshore Earthquake”...... 315
SESSION 6 – EMERGENCY RESPONSE
Mr. Ken-ichi Koike Kanagawa Water Supply Authority, Yokohama, Japan “Water Supply Control and Management in Emergency in the Wide Area Water Supply – Using the Mutual Communication Raw Water Conveyance Facilities” ...... 329 Mr. Mike Ambrose East Bay Municipal Utility District, Oakland, CA, US “Multi-Hazard Emergency Preparedness at East Bay Municipal Utility District”...... 341 Dr. Siao-Syun Ke National Science & Technology Center for Disaster Reduction, TAIWAN “The Emergency Response Plan and Preparedness of Water Supply System in Taipei City under Earthquake” ...... 353 Mr. Steve Welch Contra Costa Water District, Concord, CA, US “Earthquake Response Planning – Gaining Control of Disaster”...... 365 Prof. Tatsuo Ohmachi Tokyo Institute of Technology, Yokohama, Japan “Near-field Earthquake Displacements of the Non-liquefiable Ground Relevant to Damage to Buried Pipelines” ...... 375
Discussion Session and Closing Remarks ...... 385 Technical Tour...... 457 5th AWWARF/JWWA Water Seismic Conference Overview
Experiences from past earthquakes have highlighted the vulnerability of water systems in seismic regions in the world. Earthquakes have resulted in catastrophic water service interruptions and millions of dollars in damages. Differing seismic mitigations practices are being developed by a wide variety of organizations in the United States, Japan and Taiwan. Each practice attempts to address specific observations from past earthquakes. Seismic mitigation measures can best be improved if these practices are gathered, critically examined and disseminated to the international seismic community. Through this process we can all learn from one another.
The AWWARF/JWWA Water Seismic Conference were a series of joint workshops convened by the American Water Works Association Research Foundation (AwwaRF) and the Japan Water Works Association (JWWA). They brought together experts from utilities along with consultants and academicians from the United Sates, Japan and Taiwan to discuss both the differences and similarities of the seismic practices for water systems. Participation was strongly emphasized to focus on practical and useful information generated from experience and research. The workshops further promote the corporation and collaboration among the participating organizations in developing the state-of-the-art technologies of improving earthquake preparedness and response. Results from each workshop are documented in proceedings which are available from AWWARF and JWWA.
The US/Japan/Taiwan interchange on water system seismic practices was initially conceived in 1997 after JWWA visited East Bay Municipal Utility District (EBMUD) and received information on the EBMUD’s Seismic Improvement Program. The past history of the interchange is:
1997 - Informal Interchange during JWWA visit to EBMUD 1998 - EBMUD was invited to International Water Supply Association Conference (IWSA), Tokyo, Japan 1999 - Proposals to AWWARF and JWWA for Joint Workshops 2000 - 1st Workshop at EBMUD in Oakland, California, USA 2001 - 2nd Workshop in JWWA in Tokyo, Japan 2003 - 3rd Workshop in LADWP in Los Angeles, California USA 2005 - 4th Workshop in Kobe City in Kobe, Japan
This conference (the 5th workshop) was held at EBMUD in Oakland, California from August 15 through 17, 2007. The first day and a half of the workshop was for presentations. The afternoon of the second day was devoted entirely to questions and answers, and discussions among the participants. The third day was for a technical tour of EBMUD Walnut Creek Water Treatment Plant, San Pablo Reservoir and the construction site of the San Francisco PUC seismic isolation valve. There were 65 attendees who participated in the workshop with 19 from Japan, 2 from Taiwan, and the balance from the U. S.
1
Mr. Dennis Diemer, the General Manager of EBMUD, welcomed the participants at the opening ceremony for the conference. Mr. Roy Martinez of AwwaRF, Prof. Hiroshi Nagaoka of Musashi Institute of Technology and Mr. Donald Goralski of MCCER also delivered the opening remarks. Two keynote speeches were given by Prof. Yosihiko Hosoi of Tottori University and Prof. Thomas O’Rourke of Cornell University. 29 technical papers were presented in the following six sessions:
1. Seismic Mitigation Measures 2. Seismic measures for Pipelines 3. Outreach, Education and Communications for Earthquake Risks 4. Seismic System Evaluations 5. Earthquake Studies and Evaluations 6. Emergency Response
During the discussion session, the participants expressed strong interests in continuing and expanding the workshop in the future. The organizing committee with members from the U.S., Japan and Taiwan also discussed the possible dates and locations of the next workshop. It was agreed among the committee members that the next workshop will be held in either Japan or Taiwan within 24 months from the completion of the fifth workshop.
The conference proceedings include the technical papers, presentation slides, summary of the discussion session and the survey results from the participating water agencies.
Roy Martinez David Lee Conference Co-Chair Conference Co-Chair American Water Works Association East Bay Municipal Utility District Research Foundation
2 3 4
AGENDA 5th AWWARF/JWWA Water System Seismic Conference August 15-17, 2007 375 Eleventh Street Oakland, CA
DAY 1 – Wednesday, August 15, 2007
1. REGISTRATION
8:30-9:00 East Bay Municipal Utility District – Large Training Center – 2nd Floor
2. OPENING CEREMONY
9:00-9:10 Mr. Dennis Diemer, General Manager – East Bay Municipal Utility District 9:10-9:20 Mr. Roy Martinez, Senior Account Manager – American Water Works Association Research Foundation 9:20-9:30 Prof. Hiroshi Nagaoka, Musashi Institute of Technology – Japan Water Works Association 9:30-9:40 Mr. Donald Goralski, Senior Program Officer – Multidisciplinary Center for Earthquake Engineering Research – Earthquake Engineering to Extreme Events
3. KEYNOTE SPEECH
9:40-10:10 Prof. Yosihiko Hosoi, Tottori University, Japan, "Earthquake Countermeasures for Water Supply Systems from Standpoint of Residents" 10:10-10:40 Prof. Thomas O’Rourke, Cornell University, US, "Recent Advances in Research and Practice for the Seismic Performance of Water Supplies"
10:40-10:50 Break (10 minutes)
4. PRESENTATION PART I (15 minutes including questions & answers)
SESSION 1 Seismic Mitigation Measures
Chairpersons: Mr. Kazutomo Nakamura – Japan Dr. Fred von Hofe – US
10:50-11:05 Mr. Masaru Oneda, Tokyo Metropolitan Waterworks Bureau, Tokyo, Japan – “Seismic Measures and its Emergency Plan of Tokyo Waterworks Bureau” 11:05-11:20 Ms. Chandrika Winston, Memphis Light Gas and Water, Memphis, TN, US – “Memphis Light, Gas and Water Division Seismic Performance Objectives for Water Facilities Past, Present and Future”
JWWA-AWWARF 5th Water System Seismic Conference Page 1 of 6 Conference Agenda 17
11:20-11:35 Mr. Shigeru Hataya, Chiba Perfectural Waterworks Bureau, Chiba Perfecture, Japan – “Anti-earthquake Measures of Chiba Perfectural Waterworks Bureau” 11:35-11:50 Ms. Elizabeth Bialek and Mr. Atta Yiadom, East Bay Municipal Utility District, Oakland, CA, US – “A New Solution for a Hydraulic Fill Dam – The Case of San Pablo Dam” 11:50-12:05 Mr. Nobuhiro Hasegawa, JFE Engineering Corporation (Japanese Water Steel Pipes Association), Yokohama, Japan – “Manual for Improvement of Over Aged Reservoirs with Steel Plate”
12:05-13:30 Lunch – Sponsor: East Bay Municipal Utility District
SESSION 2 Seismic Measures for Pipelines
Chairpersons: Dr. Gee-Yu Liu – Taiwan Mr. Xavier Irias – US
13:30-13:45 Mr. Hiroaki Miyazaki, Osaka Municipal Waterworks Bureau, Osaka, Japan – “Seismic Damage Estimation of Distribution Pipes” 13:45-14:00 Mr. David Tsztoo, East Bay Municipal Utility District, Oakland, CA, US – “Challenges of the Claremont Tunnel Seismic Upgrade Project” 14:00-14:15 Mr. Yukio Mabuchi, Waterworks & Sewerage Bureau, City of Nagoya, Japan – “Earthquake Countermeasures in Nagoya” 14:15-14:30 Mr. Ahmed Nisar, MMI Engineering, Oakland, CA, US – “Fault Crossing Design of a Critical Large Diameter Pipeline”
14:30-14:45 Break (15 minutes)
SESSION 3 Outreach, Education and Communications for Earthquake Risks
Chairpersons: Mr. Munetaka Abe – Japan Mr. Brian Sadden – US
14:45-15:00 Mr. Kazuhiko Mizuguchi, Kobe Municipal Waterworks, Kobe, Japan – “Seismic Practices and Strategies of Public Relations in Kobe City” 15:00-15:15 Prof. Adam Rose, University of Southern California, US – “Regional Economic Analysis of Earthquake Losses, Mitigation and Resilience” 15:15-15:30 Dr. Nagahisa Hirayama, Disaster Reduction and Human Renovation Institute, Kobe, Japan – “Participatory Planning in Development of Comprehensive Crisis Management Plan for Water Supply Authorities”
JWWA-AWWARF 5th Water System Seismic Conference Page 2 of 6 Conference Agenda 18
15:30-15:45 Mr. Luke Cheng, San Francisco Public Utilities Commission, San Francisco, CA, US – “Seismic Aspects of the SFPUC Water System Improvement Program” 15:45-16:00 Mr. Shinji Nakayasu, Hanshin Water Supply Authority, Hyogo, Japan – “Information Provision to Residents on Construction of Regulating Reservoir at Landslide Site Caused by an Earthquake”
16:00-16:10 Break (10 minutes)
SESSION 4 Seismic System Evaluations
Chairpersons: Prof. Tatsuo Ohmachi – Japan Prof. Adam Rose – US
16:10-16:25 Mr. Kazutomo Nakamura, Japan Water Works Association, Tokyo, Japan – “A Case Study on How PIs Should Be Applied in Evaluating Seismic Performance Along with the Water Works Guidelines” 16:25-16:40 Mr. Yasuhiko Sato, Japan Water Research Center, Tokyo, Japan – “Function Diagnosis Method to Improve Earthquake Resistance of Water Supply Facilities” 16:40-16:55 Mr. Noboru Murakami, Hachinohe Water Supply Authority, Hachinohe, Japan – “Nejo Purification Plant Water System Facilities Today” 16:55-17:10 Mr. Hidehiko Aihara, Yokohama City Waterworks Bureau, Japan – “The Quakeproof Diagnosis of Waterworks Facilities in Yokohama City” 17:10-17:25 Ms. Crystal Yezman, Santa Clara Valley Water District, San Jose, CA, US – “Santa Clara Valley Water District Reliability Program, Implementing Improvements for Seismic Response”
5. GROUP PHOTO
17:30-18:00 East Bay Municipal Utility District – 1st Floor Lobby
6. CONFERENCE DINNER AT SCOTT’S SEAFOOD, Jack London Square Sponsor: American Water Works Association Research Foundation
18:30-21:00 Dinner
JWWA-AWWARF 5th Water System Seismic Conference Page 3 of 6 Conference Agenda 19
DAY 2 – Thursday, August 16, 2007
7. PRESENTATION PART II (15 minutes including questions and answers)
SESSION 5 Earthquake Studies and Evaluations
Chairpersons: Prof. Hiroshi Nagaoka – Japan Mr. David Pratt – US
9:00-9:15 Prof. Masanobu Shinozuka, University of California, Irvine, US – “A Sensor Network for Real-Time Damage Location and Assessment” 9:15-9:30 Mr. Munetaka Abe, Japan Water Works Association, Tokyo, Japan – “Damages to Water Supply Facilities by the Noto Peninsula Earthquake in 2007 and Restoration Works and Issues” 9:30-9:45 Mr. Jianping Hu, Los Angeles Department of Water and Power, Los Angeles, CA, US – “Seismic Performance Evaluation of LADWP Water Supply System Using GIRAFFE” 9:45-10:00 Dr. Gee-Yu Liu, National Center for Research on Earthquake Engineering, TAIWAN – “Seismic Repair Rate Analysis and Risk Assessment of Water Pipelines” 10:00-10:15 Mr. Kuniaki Nakamura, Fukuoka City Waterworks Bureau, Fukuoka, Japan – “Emergency Measures - A Study of the Fukuoka West Offshore Earthquake”
10:15-10:40 Break (25 minutes)
SESSION 6 EMERGENCY RESPONSE
Chairpersons: Mr. Yasuhiko Sato – Japan Mr. John Vrymoed – US
10:40-10:55 Mr. Ken-ichi Koike, Kanagawa Water Supply Authority, Yokohama, Japan – “Water Supply Control and Management in Emergency in the Wide Area Water Supply – Using the Mutual Communication Raw Water Conveyance Facilities” 10:55-11:10 Mr. Mike Ambrose, East Bay Municipal Utility District, Oakland, CA, US – “Multi-Hazard Emergency Preparedness at East Bay Municipal Utility District”
JWWA-AWWARF 5th Water System Seismic Conference Page 4 of 6 Conference Agenda 20
11:10-11:25 Dr. Siao-Syun Ke, National Science & Technology Center for Disaster Reduction, TAIWAN – “The Emergency Response Plan and Preparedness of Water Supply System in Taipei City under Earthquake” 11:25-11:40 Mr. Steve Welch, Contra Costa Water District, Concord, CA, US – “Earthquake Response Planning – Gaining Control of Disaster” 11:40-11:55 Prof. Tatsuo Ohmachi, Tokyo Institute of Technology, Yokohama, Japan – “Near-field Earthquake Displacements of the Non-liquefiable Ground Relevant to Damage to Buried Pipelines”
12:00-13:30 Lunch – Sponsor: East Bay Municipal Utility District
8. DISCUSSION (With English – Japanese Translation)
Chairpersons: Prof. Masanobu Shinozuka – US Prof. Yoshihiko Hosoi – Japan Dr. Craig Davis – US Prof. Hiroshi Nagaoka – Japan
13:30-14:50 Discussions
14:50-15:10 Break (20 minutes)
15:10-17:00 Discussions
9. CONCLUDING REMARKS
17:00-17:10 Mr. Roy Martinez – American Water Works Association Research Foundation 17:10-17:20 Prof. Hiroshi Nagaoka – Japan Water Works Association
10. RECEPTION AT PACIFIC COAST BREWERY Sponsors: Multidisciplinary Center for Earthquake Engineering Research and American Water Works Association Research Foundation
17:30-19:00 Reception
JWWA-AWWARF 5th Water System Seismic Conference Page 5 of 6 Conference Agenda 21
DAY 3 – Friday, August 17, 2007
11. TECHNICAL TOUR
Tour Coordinator – Mr. Chieh Wang, East Bay Municipal Utility District
8:30-9:30 Tour EBMUD Emergency Operations and Oakland Control Centers
9:30-10:15 Departure by bus and travel
10:15-11:45 Tour EBMUD Walnut Creek Water Treatment Plant
12:15-13:45 Lunch at San Pablo Reservoir Picnic Area
14:45-16:00 Tour of SFPUC 96-inch Isolation Valve Project (Fremont)
17:00 Arrive at EBMUD Administration Building
17:30 Arrive at Pickwick Hotel (San Francisco)
JWWA-AWWARF 5th Water System Seismic Conference Page 6 of 6 Conference Agenda 22
5th AWWARF/JWWA Water System Seismic Conference
KEYNOTE SPEECH
Prof. Yosihiko Hosoi, Tottori University, JAPAN, "Earthquake countermeasures for water supply systems from standpoint of residents"
Prof. Thomas O’Rourke, Cornell University, US, "Recent Advances in Research and Practice for the Seismic Performance of Water Supplies"
23 24 RECENT ADVANCES IN RESEARCH AND PRACTICE FOR THE SEISMIC PERFORMANCE OF WATER SUPPLIES
T.D. O’Rourke Thomas R. Briggs Professor of Engineering Cornell University
ABSTRACT
Some of the most important recent advances in research and practice for the seismic performance of water supply systems have been associated with the 1) development and application of models for complex water supply system performance during earthquakes, and 2) large scale soil-structure interaction experiments. Numerical simulations of water supply performance during and after earthquakes has been facilitated by the development of programs that account for water flow under conditions of heavy damage after an earthquake, multi-scale modeling techniques to represent the network behavior of trunk and distribution pipelines, and visualization through geographical information systems (GIS). In the US, large scale soil-structure interaction experiments have been facilitated through the George E. Brown, Jr Network for Earthquake Engineering Simulation (NEES) http://www.nees.org/ , which is a nation-wide network of test sites supported by the National Science Foundation (NSF) interconnected through high performance internet for real-time physical and numerical interactive modeling.
Research supported by MCEER at Cornell University and the Los Angeles Department of Water and Power (LADWP) has focused on the development of a decision support system to plan operations, emergency response, and new system facilities and configurations to optimize water supply performance during and after earthquakes. The system is generic, and the architecture of its computer programs is adaptable to any water supply. The system works in conjunction with an easily accessible hydraulic network model, EPANET, and a special program for damaged network flow modeling, known as Graphical Iterative Response Analysis for Flow Following Earthquakes (GIRAFFE).
The decision support system was developed using the LADWP water supply as a test bed. As applied to the LADWP network, the computer model simulates all 12,000 km of water trunk and distribution pipelines and related facilities (e.g., tanks, reservoirs, pressure regulation stations, etc.) in the LADWP system. The decision support system accounts for the aggregated seismic hazard in Los Angeles through an ensemble of 59 scenario earthquakes. The 59 scenario earthquakes also provide a library of seismic scenarios, from which engineers can select specific scenarios or combinations of scenarios to assess system performance. The decision support system works with risk and reliability assessment tools to provide metrics of system performance. The computer simulations account for the interaction of the water and electric power supplies, and model output can be used to evaluate the regional economic and community impacts of water losses. All system input and output can be visualized through GIS with advanced query logic and web-based features. The simulations are dynamic in time, and can account for loss of
25 service as tanks and local reservoirs lose water over time through leaks and breaks in pipelines.
System simulations have been performed to show the aggregated effects during an earthquake of loss in functionality of transmission pipelines (Los Angeles Aqueducts 1 and 2), loss of electric power due to earthquake effects, damage from local, permanent ground deformation to trunk and distribution pipelines, system-wide damage from transient ground deformation effects, and damage to facilities. The damage can also be de-aggregated to show the most important sources and quantify their ramifications on the system.
System performance is expressed in terms of system serviceability index, SSI, which is the ratio of flow at demand nodes before and after the earthquake. There are 1,052 demand nodes that are geographically distributed throughout the system. The SSI can be determined for the entire system or for any part of the system so that the spatial variability of SSI can be evaluated.
Studies for LADWP with the decision support system to date have focused on a repeat Northridge earthquake scenario. The studies show the great importance of dynamic behavior over time, especially during the first 24 hrs after the earthquake when leaking water through damaged pipelines diminishes local tank and reservoir levels, thereby reducing SSI. The studies show the importance of disruption in flow from the Los Angeles Aqueducts and electric power losses. Each of these effects has similar consequences for the system, resulting in low SSI for water service areas in the northern part of the system. The studies also show the effects of lost storage capacity. Over the past 10 years several large reservoirs have been taken out of service because of water quality concerns, resulting in a reduction of approximately 30 X 106 m3 of readily available water and placing greater dependence on the Los Angeles Reservoir. For peak summer demands, the SSI for the entire network 24 hrs after the earthquake is increased by 30% if the out-of-service reservoirs are restored on an emergency basis. The decision support simulations demonstrate explicitly where the locally most important effects are and indicate what pipelines and facilities are most critical for effective performance.
Collaborative research on ground rupture effects on underground pipelines is in progress with the NEES equipment sites at Cornell University http://nees.cornell.edu/index.htm and Rensselaer Polytechnic Institute (RPI) http://nees.rpi.edu/. The Cornell facility provides for full-scale testing that concentrates on detailed soil-structure interaction. It permits accurate representation of both the soil and buried lifeline in the vicinity of ground rupture. The RPI facility provides an excellent complement. Through multi-g scaling, larger prototype dimensions and rates of loading can be tested.
Large scale and centrifuge tests have focused on steel and high density polyethylene (HDPE) pipelines. The large-scale experiments at Cornell are the largest tests ever performed on ground rupture effects on pipelines in the laboratory. The tests involve 1.2 m of left lateral strike-slip fault movement of approximately 60 m3 of partially saturated sand with pipelines embedded at a depth of 1m to top of pipe at a fault crossing angle of 65°.
26 The pipeline orientation with respect to the ground rupture plane generated tension and bending in the first series of tests. A second series is currently under way in which right lateral strike-slip fault movement will generate compression and bending in the pipelines. Four large scale experiments on 400-mm-diameter HDPE pipelines, both without internal water pressure and with 500 kPa of internal water pressure, have been performed.
The research program has been used to develop advanced sensor technology. A pipeline robot equipped with a laser profiling device was used to obtain continuous digital images of the interior shape of the pipeline both before and after ground rupture. The digital images provide 3-D data on the degree of ovaling experienced by the pipeline and the cross-sectional flexural strains in the pipe. Tactile force sensors were used to measure the distribution of pressure around the pipe circumference due to soil-pipe reactions during ground rupture. A tactile force sensor is a fabric in which is embedded a matrix of polymeric resistive contacts. Over 2000 restive contacts were involved in the 500 mm x 400 mm sheets that were used in the experiments. A protective Teflon sheet was used to isolate the tactile force sensors from shear cross-sensitivity effects.
The experiments have demonstrated that the HDPE pipelines are capable of sustaining large deformation without loss of service during ground rupture, on the order of several meters, depending of fault crossing angle. The experimental evidence and analytical modeling of lateral soil forces imposed on the pipelines have resulted in the development of a design chart to predict horizontal forces on the pipeline from ground rupture as a function of soil properties, pipe diameter, and depth of pipe burial. Equations accounting for force-displacement interaction during relative pipeline movement in the soil have also been developed.
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5th AWWARF/JWWA Water System Seismic Conference
SESSION 1 Seismic Mitigation Measures
Mr. Masaru Oneda, Tokyo Metropolitan Waterworks Bureau, Tokyo, JAPAN – “Seismic Measures and its Emergency Plan of Tokyo Waterworks Bureau”
Ms. Chandrika Winston, Memphis Light Gas and Water, Memphis, TN, US – “Memphis Light, Gas and Water Division Seismic Performance Objectives for Water Facilities Past, Present and Future”
Mr. Shigeru Hataya, Chiba Perfectural Waterworks Bureau, Chiba Perfecture, JAPAN – “Anti-earthquake Measures of Chiba Perfectural Waterworks Bureau”
Ms. Elizabeth Bialek and Mr. Atta Yiadom, East Bay Municipal Utility District, Oakland, CA, US – “A New Solution for a Hydraulic Fill Dam – The Case of San Pablo Dam”
Mr. Nobuhiro Hasegawa, JFE Engineering Corporation (Japanese Water Steel Pipes Association), Yokohama, JAPAN – “Manual for Improvement of Over Aged Reservoirs with Steel Plate”
29 30 Seismic Measures and its Emergency Plan of Tokyo Waterworks Bureau
Masaru ONEDA
ABSTRACT
Tokyo Waterworks Bureau ranks the seismic resistance measures as one of the most important problems, so we have tried for the measures from both sides of facilities improvement and system of emergency restoration up to now. Tokyo Waterworks Bureau settles on “The Plan of Projects for Seismic Measures” for the facilities improvement. The purposes of this plan are to reduce the damage of the water supply facilities by the earthquake, and to secure the water supply to the customers as much as possible. Up to now, we have promoted strengthening of the water service system such as making earthquake-proof of the Yamaguchi Reservoir and water distribution reservoirs. And we have constructed emergency water tanks to secure the drinking water against the earthquake disaster. Moreover, “The Plan of Emergency Seismic Measures” is settled to restore the water supply facilities and to do emergency water supply to the customers smoothly when the earthquake disaster occurs. On the other hand, the Central Disaster Prevention Council of Japanese government made public “Measures outline of the Earthquake with an Epicenter in the Tokyo Metropolitan Area” in September 2005. When the water supply facilities to the capital center organizations, etc. are damaged, this outline requests to restore the facilities within three days after the earthquake occurs. Therefore, Tokyo Waterworks Bureau settled on “New Facilities Improvement Long Term Conception” in November 2006. In this plan, we decided that we make the water supply routes to the capital center organizations, etc. earthquake-proof by priority.
Masaru ONEDA, Director for Construction Division, Construction Section, Bureau of Waterworks, Tokyo Metropolitan Government, 8-1 Nishi-Shinjuku 2-Chome, Shinjuku-ku, Tokyo 163-8001 Japan
31 OUTLINE OF TOKYO WATERWORKS
Tokyo Waterworks Bureau began supplying water in 1898. The water resource volume currently secured by us is 6,230,000m3 per day. And water is supplied to the area of 1,222km², and for 12.25 million people in the entire 23-wards area and 25 cities in the Tama area as of March 2006. In addition, we provisionally supply water to three cities that are not included in the service area of Tokyo Waterworks Bureau. And the capacity of purification facilities is 6,860,000 m³ per day, total length of water distribution pipes is 25,000km. In 2005 FY, the maximum daily water supply volume is 4,980,000m3. It is 5,080,000m3 if we include provisionally supply water to the three cities. Tokyo is the center of Japanese politics, economy, and culture. And, Tokyo is one of the cosmopolitan cities that give big influence to the world. A lot of people gather and live besides 12 million Tokyo citizens, and ceaseless accumulation of industry and commerce has been done. It leads to not only the influence on the politics of Japan but also an international confidence losing of Japan if the function of the Tokyo water service stops. Additionally, in Tokyo where there are a lot of high medical institution and research organizations, water service is exactly a lifeline, and water supply must not stop at one time. Thus, Tokyo Waterworks Bureau not only supports the citizen's life and activity but also greatly contributes to the development of Tokyo.
SEISMIC MEASURES OF TOKYO WATERWORKS BUREAU
Outline of Seismic measures
Recent years, the severe earthquakes occurred one after another in Japan. About twelve years have already passed from The Great Hanshin-Awaji Earthquake that caused unprecedented damage. The various standards concerning earthquake were reviewed in Japan with this earthquake. However, large earthquakes occurred such as The Niigata Chuetsu Earthquake, and The Noto Peninsula Earthquake, etc. and they had caused the serious damage to the water supply facilities. On the other hand, The Chiba Northwest Earthquake occurred in the metropolitan area the year before last. This earthquake registered the seismic intensity 5-upper in Adachi Ward in Tokyo after an interval of thirteen years in the metropolitan area. Therefore, the possibility of the Earthquake with an Epicenter in the Tokyo Metropolitan Area to be occur increases. Tokyo is a capital of Japan, and the center of Japanese economy. Therefore, the function recoveries with the early moment are requested at the earthquakes. Especially, the water supply facilities are indispensable for the daily life water such as rest rooms and baths. In addition, water is important also for cooling such as the emergency electric supply units and computers these are necessary for operating important equipments of the capital center organization. Moreover, the shortage of water in the medical institution becomes obstacles of the operation and the dialysis, etc., and is related directly to victim's life. Therefore, we locate the seismic measures to one of the high-priority issues, and are working from both sides of facilities improvement and system of emergency restoration. Concretely, Tokyo Waterworks Bureau settles on “The Plan of Projects for Seismic Measures” for the facilities improvement. The purposes of this plan are to reduce the damage of the water supply facilities by the earthquake, and to secure the water supply to the customers as much as possible. Moreover, “The Plan of Emergency Seismic Measures” is settled to restore the water service facilities and to do
32 Seismic Measures of Tokyo Waterworks Bureau
The Plan of Projects for Seismic Measures The Plan of Emergency Seismic Measures
Reinforcement for Seismic Resistance Staff Gathering
Improvement, Reinforcement Emergency Restoration Reinforcement of the Water Supply System Emergency Water Supply
Securing of Drinking Water Practice and Enhancement of Emergency In-service Training Water Supply
Figure 1. The System of Seismic Measures
emergency the water service facilities and to do emergency water supply to the customers smoothly when the earthquake disaster occurs. (Figure 1)
The Plan of Projects for Seismic Measures
Tokyo Waterworks Bureau made extended 7th plans from 1973 FY to 2001 FY called “The Plan for Prevention of Earthquake Disaster” and had advanced the seismic measures. Moreover, we renamed the plan to “The Plan of Projects for Seismic Measures” in 2002 FY, and have been working on “reinforcement for seismic resistance of facilities” and “securing of drinking water” as the plan period from 2005 FY to 2007 FY now.
Reinforcement for seismic resistance of water distribution reservoirs, etc.
After The Great Hanshin-Awaji Earthquake (1995), we executed an earthquake-proof diagnosis of the embankment of the Yamaguchi Reservoir and the Murayama-shimo Reservoir. As a result of diagnosis, it became clear that the embankment of the Yamaguchi Reservoir and the Murayama-shimo Reservoir would be damaged when great earthquakes occurs. We decided to carry out the reinforcement work of the embankment in consideration of the importance of these Reservoirs and the present condition that urbanization has advanced under the embankments. The reinforcement work of the Yamaguchi Reservoir completed in 2002 FY, and we are executing the reinforcement work of the Murayama-shimo Reservoir now. On the other hand, the structures such as the water purification plants, the water distribution reservoirs, and the pumping stations, etc. are constructed based on the seismic design after the good ground is selected. Moreover, enough foundation works were given to facilities in case of constructing them unavoidably on weak grounds. However, in the Great Hanshin-Awaji Earthquake, damages were caused in the facilities that were thought to be strong for earthquakes, and large-scale water suspensions were generated. Based on such a situation, Tokyo Waterworks Bureau executes
33 seismic diagnosis for facilities that designed before present seismic design guideline was enacted, and if necessary executes reinforcement for seismic flexible resistance of these facilities. lock ring
Making pipeline earthquake-proof restraint projection To reduce the damages of the water suspensions at the earthquakes, and to ensure stable water supply, Figure 2. Mechanism of NS type Joint we are executing the replace project of aged pipes (We call it K-Zero project.). In the project, we execute replacement of aged pipes such as the cast-iron pipes to earthquake resistance pipes such as the ductile iron pipes, and we are executing construction aggressively aiming at completing it 2013 FY now. Moreover, when replacing it, we positively adopt the pipe that has the slipping out prevention joint such as the NS type ductile iron pipe. (Figure 2)
Reinforcement of the water supply system
The water supply system is composed of water storage facilities, intake facilities, raw water transmission facilities, purification facilities, water transmission and distribution facilities, and water supply equipments. Therefore, these facilities must function in union to secure the water supply at the earthquake. Moreover, it is technically difficult to make facilities earthquake-proof completely. Not only the reinforcement for seismic resistance of individual facilities but also the reinforcement for seismic resistance of the entire water supply system is important. Therefore, Tokyo Waterworks Bureau has aimed at the stabilization of the water supply system and advances the construction of water transmission pipe network, the construction of cross-supply pipes with neighboring water utilities, and the improvement to block distribution system. (Figure 3, Figure 4)
Construction of Emergency Water Tank (Securing of drinking water)
At the earthquake, we think that we cannot avoid temporary water suspension by the damage of the pipes. Therefore, securing the drinking water is indispensable. When the earthquake occurs, drinking water required for person is assumed three liters per day for the life maintenance. We have
Asaka, Misono Higashi-Murayama Ozaku Misato
Distribution Main Block
Sakai Kanamachi
Distribution Sub-main Nagasawa Kinuta Block Main Transmission Pipe Purification Plant Construction necessity route Water Supplying Station Figure 3. Transmission Pipe Network Figure 4. Block Distribution System
34 established bases for emergency water supply, each of which is placed within approximately every 2km to be reached from any place in Tokyo. And, we have constructed Emergency Water Tanks at the region where the purification plants and the water supplying stations do not exist in the vicinity.
Moreover, we transport the drinking water by car from the purification plants and the water supplying stations to the refuges away by 2km or more, and execute the emergency water supply. And, we completed the construction of the emergency water tanks in 2005 FY because we have secured an enough volume of water. Hereafter, we will renew them premeditatedly according to aging. We had constructed the Emergency Water Tanks of 1,500m3 46 places in the entire 23-wards area, and 7 places in the Tama area. Moreover, the small-scale emergency water tanks of 100m3 were constructed 22 places in the entire 23-wards area, and 3 places in the Tama area. Adding the numbers of the purification plants and the water supplying stations to these, Tokyo Waterworks Bureau has 97 places of the emergency water service stations in the entire 23-wards area, and 103 places in the Tama area. And total of the emergency water service stations are 200 places. As a result, the secured volume of water is about 1.03 million cubic meters in total, and this is an amount that 12 million citizens of Tokyo can consume for four weeks. (Figure 5, Figure 6)
TREND OF SEISMIC MEASURES IN RECENT YEARS
The Central Disaster Prevention Council “Measures outline of The Earthquake with an Epicenter in the Tokyo Metropolitan Area”
The Headquarters of Earthquake Research Promotion of the government is forecasting that the probability is 70% that the earthquake of magnitude about 7 will occur at South-Kanto within 30 years in the future. Moreover, The Central Disaster Prevention Council also pointed out the imminence of the Earthquake with an Epicenter in the Tokyo Metropolitan Area of magnitude 7 classes. This conference announced “Estimation of damage of the Earthquake with an Epicenter in the Tokyo Metropolitan Area” in February 2005, and settled on “Measures Outline of the Earthquake with an Epicenter in the Tokyo Metropolitan Area” in September of the same year. This is because, when the severe earthquake occurs in the capital region, a large area disaster emergency measure that
emergency water supply tap
emergency stop valve
non-utility generation facility
emergency water Purification plants and water supplying stations(122) distribution main supply pump circulation pump Emergency Water Tanks(78) Figure 5. Location of Emergency Water Figure 6. Image of Emergency Water Tank Service Stations
35 extends over the capital and the vicinity prefectures is necessary. Therefore, the continuance of the capital center organizations such as the political function, the administrative function, and the economic central function, etc. of our country is indispensable. The outline requests that the supply lines to the capital center organizations and important medical facilities are made earthquake-proof, multiplex, and disperse to the water utilities. Moreover, when the water supply facilities that supplied to the capital center organizations, etc. are damaged, the Outline requests to restore within three days by priority after the earthquake occurs, and sets the restoration target of other water supply facilities within 30 days. The capital center organizations and important medical facilities that we are considering are 81 functions. 1 Politics and administrative function: The Diet, Government Ministries and Agencies, Tokyo Metropolitan Government, and Embassies, etc. (39 functions) 2 The economic function etc.: The Central bank, The computer center of the main financial institutions (21 functions) 3 Tertiary emergency medical institution: (21 functions) Waterworks play the role to supply the cooling water, etc. of various equipments. Therefore, we should promptly make cooling water available in the capital center organizations. Moreover, multiplexing the water supply routes to the capital center organizations and making the base facilities earthquake-proof are requested.
“Estimation of the damage in Tokyo by the Earthquake with an Epicenter in the Tokyo Metropolitan Area” by Tokyo disaster prevention conference
To defend citizens’ lives and the properties, to promote the earthquake measures, and to improve disaster prevention consideration of citizen of Tokyo, Tokyo Metropolitan Government made original estimation of damage public, receiving the estimation of the damage in Tokyo by Earthquake with an Epicenter in the Tokyo Metropolitan Area that the Central Disaster Prevention Council made public in February 2005. The assumed earthquake was the Tokyo Bay Northern part Earthquake and the Tama inland Earthquake. The scales of the earthquakes were M6.9, M7.3, and the hypocenter depths were about 30-50 kilometers respectively, and the technique of estimation of damage is as follows. In this estimation of damage, the water suspension rate in 23-wards by the Tokyo Bay Northern part Earthquake is assumed to be 46%. And, the water suspension rate in the Tama area by the Tama inland Earthquake is assumed to be 25%.
Estimation of damage technique (Figure 7)
1 The water suspension rate is calculated from the material damage rate of the pipes calculated by the speed distribution of the ground and the liquefaction distribution. 2 When a large-scale power failure occurs because the substation received damage, temporary water suspension is generated by the stop of the function of the base facilities. However, water suspension will recover by switching the electric power system in a short time. Therefore, the functions stops by struck of the base facilities are not targeted. 3 The relation between the damage rate and the water suspension rate adopts the technique of Kawakami (1996) set based on the damage realities at the past earthquakes including The Great Hanshin-Awaji Earthquake.
36 Distribution Pipe Length
Speed of the Standard Damage Rate Ground of the Ground Speed Correction coefficient of Material kind and Perilousness of Correction coefficient of Caliber of Pipe Liquefaction Liquefaction Risk Rank (PL)
Pipe Damage Rate
Water Suspension Rate
Figure 7. Calculation flow of water suspension rate
4 The damage rate of the water distribution pipes of each mesh that divides Tokyo into 250m×250m mesh is calculated based on the damage realities at the past earthquakes including The Great Hanshin-Awaji Earthquake. And it is corrected by the liquefaction risk rank, the material kind of the pipe, and the caliber of the pipe.
Relational expression of water suspension rate with damage rate of water distribution pipe (Based on the damage realities at the past earthquakes including The Great Hanshin-Awaji Earthquake)
1 Water suspension rate (next day of earthquake) = 1 / {1+0.307× (water distribution pipe damage rate)-1.17} 2 Water distribution pipe damage rate (damage number / km) = Number of water distribution pipe damage / distribution pipe length (km) 3 Number of water distribution pipe damage = Standard damage rate × correction coefficient of liquefaction risk rank ×correction coefficient of material kind and caliber of pipe × pipe length (TABLE I, TABLE II) Standard damage rate (It is based on the damage realities at the past earthquake including The Great Hanshin-Awaji Earthquake) Standard damage rate (number /km) = 2.24 × 10-3 × (the speed of the ground (cm/sec)-20) 1.51
TABLE I. CORRECTION COEFFICIENTS OF LIQUEFACTION RISK RANK PL Rank PL=0 0 37 TABLE II. CORRECTION COEFFICIENTS BY THE MATERIAL KIND AND THE CALIBER OF THE PIPES (Based on the damage realities at The Great Hanshin-Awaji Earthquake.) Pipe Material Caliber 75mm or less 100-250mm 300-450mm 500-900mm 1000mm or more Ductile Iron Pipe 0 (Earthquake-proof Joint) Ductile Iron Pipe 0.6 0.3 0.09 0.045 (Normal Joint) Cast Iron Pipe 1.7 1.2 0.4 0.15 Steel Pipe 0.84 0.42 0.24 Polyvinyl Chloride Pipe (PVC) 1.5 1.2 Asbestos Cement Pipe 6.9 2.7 1.2 NEW FACILITIES IMPROVEMENT LONG TERM CONCEPTION OF TOKYO WATERWORKS BUREAU Tokyo Waterworks Bureau ranks the seismic resistance measures as one of the most important problems, and has promoted the seismic resistance measures steadily based on The Plan of Projects for Seismic Measures, up to now. However, the reviewed new estimation of damage exceeds that in 1997, and it is forecast that the influence on the water supply facilities is huge. Moreover, because a part of the supply route to the water taps is damaged even if individual facilities are made earthquake-proof, it is feared that securing the water supply becomes difficult. Therefore, we decided that at once the seismic measures were progressed based on the following basic policies without waiting for the decision of The Plan of Projects for Seismic Measures from 2008 FY for the next term. Reinforcement of seismic resistance To make up the water supply system that can be stably supplied not only peacetime but also at the earthquake, the measure is promoted by the following policy. 1 We give priority to making the water supply facilities of the supply routes about the capital center organizations and the tertiary emergency medical institutions earthquake-proof, and execute it at the early stage. (Figure 8) 2 We improve the earthquake resistance of the water supply facilities considering distribution pipe continuousness from the water distribution station resource facilities to the taps. Especially, to secure some water distribution pipe purification capacity at the early stage, we promote making each purification system Tertiary Emergency Medical Institutions earthquake-proof, considering the Making to continuousness from the receiving earthquake-proof Capital Center Organizations wells to the water distribution reservoirs is advanced. Figure 8. Earthquake-proof of Important Route 38 TABLE III. PERFORMANCE INDICATOR OF SEISMIC MEASURES (PI) Past Records Target Ten Years After 2005 FY (2016 FY) 100 Ductile Iron Pipe Rate (%) 98 (2013 FY) Earthquake-proof Joint Rate (%) 20 35 Earthquake-proof Rate of Supply Route to 2 100 Important Facilities (%) Earthquake-proof Rate 0 60 of Purification Plants (%) Earthquake-proof Rate 31 95 of Water Distribution Reservoirs (%) 3 We clarify the priority level, and making the water supply facilities earthquake-proof is advanced effectively. The water supply facilities are systems that consist of huge facilities. It requires a long tract of years and huge cost to complete making all facilities earthquake-proof. It is important to clarify the priority level of improvement at the same time as hurrying up making of the weak points and important facilities earthquake-proof in order to advance reinforcement for seismic resistance of the water supply facilities effectively. Especially, it is necessary to renew old pipes that are weak to earthquake in the east area of 23-wards where big damage is assumed by the Earthquake with an Epicenter in the Tokyo Metropolitan Area. (TABLE III) Strengthening of backup function To improve the stability of the water supply at the accidents and the earthquakes, Tokyo Waterworks Bureau promotes the measure by the following policy. 1 To strengthen the backup function, we promote the improvement of water supplying stations and non-utility generating facilities. It is important to secure appropriate capacity of the water distribution reservoirs against the emergency to do an effective backup at the accident. Moreover, it is necessary to construct the water distribution reservoirs newly and to reorganize the wide supply area. Therefore, Tokyo Waterworks Bureau advances the construction of water distribution reservoirs that become bases in the water supply districts, and secures the capacity of the water distribution reservoirs of 12 hours of the amount of the maximum daily supply in preparation for the change by time and accidents. (As of the end of 2005 FY: about 70%) Moreover, to supply water with stability at the large area power failure, we are advancing to equip non-utility generating facilities to the purification plants and the water supplying stations, etc. 2 Construction of network of transmission pipes To do the efficient water supply control and management and strengthen the backup function at emergency, Tokyo Waterworks Bureau constructs the large area transmission pipes network that connects between purification plants and water distribution reservoirs and between water distribution reservoirs. Moreover, in the Tama area we make the network of main distribution pipes that are like tree branch now, in order to improve their mutual flexibility and the backup function. 39 REVISION OF EMERGENCY MEASURES PLAN Tokyo Metropolitan Government has received “Estimation of damage of the Earthquake with an Epicenter in the Tokyo Metropolitan Area” and “Measures Outline of the Earthquake with an Epicenter in the Tokyo Metropolitan Area” of the Central Disaster Prevention Council, and settled on “Estimation of damage of Tokyo by the Earthquake with an Epicenter in the Tokyo Metropolitan Area” that forecast the damage of each cities, towns, and villages more in detail in March, 2006. The estimation of damage of the water supply facilities reflected Ductile Iron Pipe Rate and Earthquake-proof Joint Rates of each city, town, and village, based on the condition of the ground data and the liquidizing index, etc. Moreover, Tokyo Waterworks Bureau revised “The Plan of Emergency Seismic Measures” to improve “Mobility” with which we can deal with the earthquake promptly and “Effectiveness” with which we can carry out our mission steadily with the large earthquake. Establishment of Water Supply Headquarters When the earthquake causes damage, it is difficult to act in the emergency measures in the usual organization. Therefore, when the earthquake more than seismic intensity 6-under occurs, and the extensive damage occurs in the water supply facilities, the director of waterworks bureau sets up the water supply headquarters in the bureau. In this case, the post provided beforehand does the information gathering, the emergency restoration, and the emergency water supply. Moreover, when the earthquake occurs on nighttime and holiday, it is assumed that the specified standby directorate members, the specified directorate members, and the resident in the disaster measures staff house, etc. do these works as the first movement worker. (There is no change from the plan of the previous state about this.) System of emergency restoration It was clearly shown to restore struck water supply facilities in the whole area of Tokyo within 30 days. For three days after the earthquake occurs, we restore the water distribution pipe damage parts to the capital center organizations, etc. and do investigation and the water distribution control, etc. of the other facilities. Then, four days after the earthquake, we execute real restoration of the other facilities. Up to now, when the earthquake occurs on nighttime and holiday, the greater part of staff are supposed to gather in the office that is the nearest from each one’s home. The mobility at the first movement could be expected of this system. However, necessary personnel did not necessarily gather in the office that was necessary for the operation management and the emergency restoration, and there was an anxiety from effectiveness. Therefore, the effectiveness was valued, and, as a rule, the staffs assumed the gathering to the belonging office. System of emergency water supply Up to now, only staffs of a part of posts have done the emergency water supply. However, a prompt action at the first movement is especially important. Therefore, staffs are specified beforehand (about 7-10 persons per every base, about 300 persons as a whole), and when the 40 earthquake occurs, the staffs assume direct gathering to the water supply base (29 bases in the 23-wards and 16 bases in the Tama area) where it had been specified within roughly 5 km from their home. At the purification plants and water supplying stations, the staffs of the bureau do the operation management in facilities and the installations of the emergency water supply tools and materials to the emergency water supply activity and staffs of the wards and the cities do the emergency water supply to the resident. Moreover, at the emergency water tanks, the staffs of the wards and the cities are supposed to do all of the work of the operation management in facilities, the installations of the emergency water supply tools and materials, and the emergency water supplies to the resident, etc. Review of gathering standard The standards seismic intensity of the emergency disposition system was reviewed with the change of the gathering places. Tokyo waterworks bureau provided that all staffs gathered independently at the seismic intensity 5-upper or more had been observed in consideration of importance of the water supply facilities by planning that had been settled on in 1996. (All staffs gathering standard of Tokyo Metropolitan Government is seismic intensity 6-under.) However, the reinforcement for seismic resistance of the water supply facilities have advanced as about ten years pass afterwards and the rate of the ductile iron pipe becomes 98% at the end of 2005FY. (TABLE III) Moreover, in 2005, damage was not caused in the water supply facilities though seismic intensity 5-upper was observed at Tokyo due to The Northwest Chiba Earthquake, and seismic intensity 6-under was observed due to The Miyagi Offing Earthquake. Therefore, we reviewed the gathering standard seismic intensity this time, and the standard to independent gathering of the staffs that specified beforehand changed to seismic intensity 5-upper, and the standard to independent gathering of all staffs became seismic intensity 6-under. Securing of restoration constructors and restoration materials Securing of the constructors engaged in restoration is important to do restoration works adequately after the earthquake occurs. Therefore, Tokyo Waterworks Bureau has concluded the agreement with the unit price contract constructors up to now, and has maintained the cooperative relationships of the emergency restorations. This time, when contracting to the total value contract constructors, we decided to obligate the restoration cooperation at the earthquakes to do more certain restoration. Moreover, we assumed that we introduced the method to evaluate not only the price evaluation but also the responsive capability in the emergency one by one when contracting to the unit price contract constructors, and improved the incentive of the cooperation at the earthquakes. On the other hand, the manufacturers secured the restoration materials such as the water pipes by the agreement of Tokyo Waterworks Bureau and current manufacturers, and the constructors who restore the damaged facilities procure the restoration materials. In this revision, to secure the restoration materials surely, Tokyo Waterworks Bureau secures all the restoration materials of the supply routes such as the capital center organizations. And, the materials for the emergency restoration of the other routes were secured by the Waterworks Bureau and the manufacturers, and procurement was decided to doing of the Waterworks Bureau. 41 CONCLUSION We think that the emergency measures of Tokyo Waterworks Bureau came to have mobile power and execution power more than before by reviewing this earthquake measures. However, to behave each staffs according to the plan when the earthquake actually occurs, and to execute the emergency restoration and the emergency water supply, it is necessary that each office settle on “Action manual” based on this plan, and make each staff well-know. Moreover, it is necessary that we make the plan more established. Therefore, we will improve the staff's consideration by the earthquake measures training, appeal to administrative bodies such as wards and cities, and appropriate review of plans. (Figure 9) We think that we must work on the earthquake measures to secure safety and the peace of mind of the citizen’s life, and to defend the capital center organizations more than before. Figure 9. Appearance of Training REFERENCES [1] The Central Disaster Prevention Council. 2005 “Measures outline of the Earthquake with an Epicenter in the Tokyo Metropolitan Area” [2] Tokyo disaster prevention conference. 2006 “Estimation of the Damage in Tokyo by the Earthquake with an Epicenter in the Tokyo Metropolitan Area” [3] Tokyo Waterworks Bureau. 2005. “The Plan of Projects for Seismic Measures of Tokyo Waterworks Bureau” [4] Tokyo Waterworks Bureau. 2006. “The Plan of Emergency Seismic Measures of Tokyo Waterworks Bureau” [5] Tokyo Waterworks Bureau. 2006. “The Outline of Waterworks in 2006” [6] Tokyo Waterworks Bureau. 2006. “The Annual Report of Waterworks in 2005FY” [7] Tokyo Waterworks Bureau. 2006. “New Facilities Improvement Long Term Conception of Tokyo Waterworks” 42 Seismic Performance Objectives for MLGW Water Facilities Past, Present and Future Chandrika Winston, P.E. and Fred Von Hofe, Ph.D., P.E. In 2006 Memphis Light, Gas and Water (MLGW), the nation’s largest three service electric, gas and water public utility, hired a team of nationally recognized engineering consultants to perform a Multi-Hazard Risk Assessment. As part of this risk assessment, the consultant team was asked to investigate a range of seismic event scenarios resulting from seismic activity in New Madrid Seismic Zone (NMSZ). The consultant team identified seismic performance objectives used in past MLGW seismic studies and strengthening/retrofit projects. Performance objectives were then established for evaluation criteria for the current study and for future seismic strengthening/retrofit projects. This paper and the associated presentation discuss seismic performance objectives recommended by the consultant team and accepted by MLGW’s management for the current evaluation of structural and non-structural elements. It also discusses the recommended seismic performance objectives to meet MLGW’s goals for new construction and future seismic strengthening/retrofit projects. Introduction: The City of Memphis is earthquake series occurred at Marked approximately 35 miles from Marked Tree. Tree, Arkansas, which is located at what is generally considered to be the Figure 1. USGS NMSZ Seismic Event southern tip of the New Madrid Seismic Map Zone as shown in Figure 1. Memphis is not located in the NMSZ per se and is not generally considered to be a potential location/focal point of a major earthquake or seismic event. However, Memphis is in the zone of influence of the NMSZ and major earthquakes in the NMSZ will impact significantly Memphis, particularly those occurring on the southern segment. Events at Marked Tree are often used as a benchmark for events that could affect Marked Tree, AR Memphis since it is located in the area of the NMSZ closest to Memphis and one of the major events in the 1811-1812 43 Figure 2. National Seismic Hazard Map As noted in Figure 2, the 2002 USGS National Seismic Hazard Map, the United States Geological Survey (USGS) has established a level of seismic hazard in the NMZS and at Memphis approaching that of the West Coast. Memphis, TN Should a major seismic event ever occur in the southern segment of the NMSZ, water will be a critical issue. Memphis Light, Gas and Water Division will be called upon to provide potable water for human consumption, water for fire suppression, and water to meet sanitary needs. MLGW has realized the importance of the water system and for many years has been addressing the water system’s vulnerability to major seismic events. The water system is highly dependent upon the electrical system which also has substantial seismic vulnerabilities. MLGW also owns and operates the electrical system and is addressing electrical system vulnerabilities at the same time water system vulnerabilities are addressed. However, to insure electricity to meet the electrical demands of the water plants and well fields an alternative source of electricity must also be available to provide electricity in the case the electric system is seriously damaged or destroyed. History In 1989 MLGW completed an Emergency Preparedness Study that included a seismic risk assessment study and seismic mitigation plan prepared by an outside engineering consultant. As a result of the study, MLGW began to harden all of its major water plants and well fields. A water plant in MLGW’s system includes a water treatment plant and pumping station. These first upgrades were those that had a minimal cost but could yield big dividends in case of a major seismic event. It did not take long until all of the simple and easy upgrades were accomplished. The next step was to address major items that were more complex, expensive and time consuming. These fell into five categories: 1) water plant seismic retrofits, 2) water plant header valves, 3) water plant emergency generators, 4) water production well dedicated circuits, and 5) water production well seismic retrofits. Water plant seismic retrofits included the garage, aerator, filter building, pump building and equipment. Typical methodology included assessment by an engineering consultant to determine the feasibility of seismic strengthening/retrofit of the facilities and equipment. The basic procedure incorporated a review of local geological and seismological data, existing plans, one or more visits to the site, measurements, and additional data collection. The collected information was used to make preliminary calculations for structural and non-structural seismic strengthening/retrofits. These calculations were used to prepare draft specifications, and preliminary construction plans. If the study and preliminary information identified the proposed project as feasible, an engineering consultant was then hired to do final engineering and preparation of 44 construction specifications and construction plans for competitively bidding the construction of the project. Once a contractor was selected, the engineering consultant provided construction administration and full time resident inspection of the construction project. Water station header valves are used to isolate a facility or part of a facility without forcing a major shut down. The valves may be remotely or manually operated. Upgrades to the existing header valves were identified as a needed improvement to insure that a facility or part of a facility could be isolated from the entire system in case of a major seismic emergency in a matter of minutes. Header valve improvements have been in-house design projects. Typically, the project is designed by an in-house engineer who also prepares the specifications and construction drawings for the project. The design is reviewed by personnel from the Water Operations and the Water Distribution Departments. A de-watering plan is prepared to evacuate the lines in preparation for the construction. The construction is either contracted or handled internally. A water plant is never totally shut down during a header valve replacement project. Only one or two header valves are replaced at a time. Water station emergency generators serve as a back up to the electric distribution system. A generator provides an electrical supply to high service pumps and select wells on a dedicated circuit at each individual water plant and well field. Site selection at each water plant is coordinated with the Water Operations Department. An in-house engineer is assigned to prepare engineering specifications and construction drawings. The project is competitively bid and a contractor is selected and awarded a contract for the construction and installation of the generators and associated fuel tanks. Currently, seven of MLGW’s eight major water plants have generators. Most are sized at 1500 KW. However future and replacement generators will be sized at 2000 KW. All generators use diesel fuel supplied from underground storage tanks (USTs) most with 20,000 gallon capacity storage tanks. A dedicated circuit for water production wells is located at each water plant well field. The dedicated circuitry is a specifically dedicated line from the electric generator to each of the wells on the circuit. The dedicated circuit is designed and installed to make sure that the electric motors that drive the deep well vertical turbine pumps have an adequate electric supply. Approximately ten wells at each well field are on the dedicated circuit. The design and installation of the dedicated circuit is an in-house project handled by MLGW’s Electric Distribution Engineering. An in-house engineer is assigned the project. The existing circuitry is reviewed and design drawings and construction specifications are prepared. The in-house engineer is responsible for the coordination of the construction from the generator to each of the wells. Typically an MLGW Electric Distribution crew will install the dedicated circuitry. Water production well seismic strengthening/retrofits were necessary to ensure selected wells will be available to produce water in the case of a major seismic event. Previously an engineering consultant has been selected to prepare the design. The engineering consultant focused on the electric well cabinet and the electric well cabinet foundation. The engineering consultant reviewed local geological data, visited the sites, took measurements, and collected data. Using the collected information the engineering consultant performed seismic structural and non-structural calculations. Specifications and construction plans and drawings were prepared and competitive bids were taken to 45 seismically strengthen/retrofit some existing electric well cabinet and electrical cabinet foundations. The construction was in most cases administered by an in-house project engineer. Multi-Hazard Risk Assessment In 2006, MLGW’s Executive Management Team decided it was time to reevaluate the seismic strengthening/retrofits along with the electric gas and water systems vulnerabilities to other natural hazards (wind, ice, storms and flooding). It was also determined that an effective study would address not only specific facilities and components but would also address the water (and gas and electric) systems as a whole, including interdepencies on other systems such water system dependency on electric power. A request for proposals was developed for a Multi-Hazard Risk Assessment study with the following seismic objectives: 1) Evaluate the seismic performance of the electric, gas and water systems as-is system, 2) recommend measures to improve MLGW’s systems seismic performance, 3) identify system performance under various seismic scenarios, 4) develop system restoration curves. A team of nationally known consultants was hired to perform the study. Information gathering, site visits and data collections was the initial focus of the engineering consultant teams efforts. Early in the project it was realized that three of MLGW’s water plants were built before the 1960’s and that little or no consideration was given to seismic load at the time they were designed. It was also realized that these plants were the same ones identified in the first Emergency Preparedness Study as difficult, if at all possible, to seismically strengthen/retrofit. A brief review of seismic building code history is appropriate at this time. In 1992 the City of Memphis, for the first time, adopted seismic design requirements - the Southern Building Code (SBC) with local amendments diminishing the SBC requirements. In 1995, the City adopted the then current SBC without local amendments impacting seismic requirements. In 2005, the City of Memphis Adopted the International Building Code (IBC 2003). IBC 2003 require two-thirds of 2% in 50 years for non- critical facilities with respect to ground shaking, resulting, as noted in following tables, in a PGA (peak ground acceleration) of about 0.40 g. IBC also incorporates an importance factor (a multiplier on design forces of 1.5) for critical facilities. Water treatment plants and pumping stations that provide water for fire fighting and maintaining water system pressure are considered critical facilities. The resulting PGA for critical facilities is about 0.60 g. The goal of the Multi-Hazard Risk Assessment was to evaluate the seismic performance of the water plants and well fields under three scenario earthquakes or seismic events at the southern tip of the New Madrid Seismic Zone (Marked Tree, as noted previously). MLGW’s definition of performance included not only the performance of individual buildings and components, but also the performance of the system in terms of level of service to the customers after each of the scenario events. The first scenario event M6.2 was selected because it represented the lower end threshold event likely to have an affect on MLGW’s system and customers. The second scenario event selected was a M7.0 event representing an intermediate earthquake that was likely to have a significant affect on MLGW’s system and customers. The third scenario M7.7 event was 46 selected to be generally comparable to major events that occurred in the 1811-12 series of events in the NMSZ and what is generally considered to be a maximum credible event for the NMSZ. The consultant was asked to estimate the expected damage to MLGW’s utility system on a building by building and a component-by-component basis. Using estimated damage to the system buildings and components, the consultant was requested to estimate the MLGW’s system performance. The system performance was to be characterized by expected amount of service available after each scenario and by the system restoration curves. The system restoration curves are developed to give the rate at which the system is expected to be restored and are developed from data from previous experience such as the 100+ mph windstorm Elvis in 2003 which left a major portion of the City without electrical service for over a week. The second task was to make recommendations to improve the performance of MLGW’s water systems as well as gas and electric systems under each scenario. The water system was deemed especially critical because the water would be needed for fire suppression and a potable supply to meet the human needs of the community as well as the sanitary needs. Also the consultant was asked to prioritize the recommended improvements to the system. The idea was to obtain the maximum amount of benefit for each mitigation dollar spent. Figure 3 shows an overview of the MLGW Multi-Hazard Risk Assessment. Tasks 1 and 2 were mainly data gathering. Establishing performance objectives for Task 3 evaluation of component vulnerability is the subject of this paper. Previous to this study MLGW had used a combination deterministic and probabilistic approach to seismic studies and seismic strengthening/retrofits. Figure 3 Current MLGW Multi-Hazard Risk Assessment Overview Task 1 Task 2 Task 3 Hazard Evaluation System Operating Evaluate Component Characteristics Vulnerabilities Task 4 Evaluate System Performance for Each Scenario Hazard Event Task 5a Task 5b Recommendations for Evaluate Capital Improvement Specific Components Program Alternatives 47 Four of MLGW’s 8 major water plants have been strengthened/retrofitted using the previously established performance objectives shown in TABLE I. TABLE I. Performance Objectives For Previous Seismic Retrofit M 7.0 (Marked Tree) or 10% in 50 Years Ground Motion whichever is larger Building Structural Performance: Immediate Occupancy Nonstructural Equipment and Systems: Operational Level 2% in 50 Years Ground Motion Building Structural Performance: Life Safety (To protect occupants) Nonstructural Equipment and Systems: Operational Level Note that these performance objectives are a combination of probabilistic methodology and deterministic methodology. The use of deterministic methodology vs. probabilistic methodology was discussed with MLGW’s Multi-Hazard Risk Assessment consultant. After much consideration it was decided to use the probabilistic approach The probabilistic approach requires the development of seismic fragility curves that define the probability of a building or nonstructural component being damaged at any level of ground shaking. TABLE II gives a comparison of deterministic versus probabilistic ground shaking. Table II. Deterministic versus Probabilistic Scenarios Scenario PGA (g) 0.2 sec (g) 1.0 sec (g) M 6.2 0.130 0.202 0.069 M 7.0 0.239 0.353 0.189 M 7.7 0.370 0.507 0.384 Probabilistic PGA (g) 0.2 sec (g) 1.0 sec (g) 2% in 50 yrs. 0.590 0.730 0.722 2/3 of 2% in 50 yrs. 0.393 0.487 0.481 5% in 50 yrs. 0.391 0.503 0.356 10% in 50 yrs. 0.249 0.354 0.180 48 For the study MLGW’s consultant used values from the Cramer et al (2004) USGS seismic hazard data, as the best available from Shelby County. This was done because the data reflects the influence of Memphis/Shelby County soil effects. The values are approximate median values for Shelby County. Note 10% in 50 years is generally similar to but higher than a scenario M7.0 at Marked Tree. Also two thirds of 2 % in 50 year is similar to and generally a bit higher than the scenario M7.7 scenario ground motion. 2% in 50 years is much higher than a scenario M7.7 event. The City of Memphis has adopted the International Existing Building Code 2003 as its existing building code, and has been determined appropriate for use in addressing seismic retrofits (vs. the requirements of the IBC 2003 – Chapter 34). This is much less prescriptive than for new construction. Other than in the Federal sector, retrofits are generally voluntary and are not required with certain exceptions. Generally, seismic retrofit is not mandated under the City of Memphis Existing Building Code (MEBC 2005) except for change in classification of a building or changes which increase the force on structural elements by more than 5% - provisions not generally applicable to MLGW’s systems. For existing buildings Federal Emergency Management Agency (FEMA) 356 provides a number of seismic retrofit options. These include operational performance, immediate occupancy performance, life safety performance and collapse prevention performance and several earthquake design levels (50% in 50 years, 20% in 50 years, 10% in 50 years, 2% in 50 years). Seismic retrofit is not necessarily mandated or required for all buildings or structures not meeting FEMA 356 evaluation parameters. In some cases it may be more economical to remove the building and replace with a new building or structure. In other cases the building does not pose any safety threat to customers or employees. Before undertaking a seismic strengthening/retrofit, some consideration should be given to the following issues: 1) May not need to be retrofitted if they pose little or no risk to life safety or no risk to significant loss of customers. 2) Retrofitting existing building to performance levels of new construction may not be possible even though MEBC 2005 (IBC 2003) permits design to reduced IBC level seismic forces (i.e.,75% of IBC design load for new construction). 3) Non structural component retrofits are comparable to installation of new nonstructural components. 4) Retrofits should be made on a case by case basis considering engineering characteristics, cost of retrofit, importance of the facility, building or nonstructural components for life safety and /or customer service or system performance. TABLE III shows the recommended evaluation criteria for existing MLGW facilities developed as part of the Multi-Hazard study. TABLE III contains evaluation criteria for two building categories and two nonstructural categories (non-system and minor and (major) utility buildings and components). 49 TABLE III. Recommended Evaluation Criteria for Existing MLGW Facilities Buildings Non-Structural Components Seismic Hazard Non-system Major Non- System Utility System Level and Minor Utility Components Components Utility Buildings Buildings Immediate 10 % in 50 Years Life Safety Occupancy Life Safety Operational 2 % in 50 Years Collapse Life Safety Life Safety Operational Prevention Figure 4 shows the evaluation methodology that was used to evaluate MLGW’s existing building and non-structural elements. If both criteria in TABLE III were met, the building or non-structural element were deemed satisfactory and no retrofit was needed. If the building or non-structural element failed one or both of the criteria in TABLE III, the building or non-structural element was a candidate for a seismic retrofit. The failures were then prioritized based on the risk to life safety and the importance of each facility to the overall water system operation. Figure 4. Evaluation Methodology Evaluation of Existing MLGW Facilities Fails One or Both Passes Evaluation Criteria Both Retrofit Retrofit May Be Desired: Prioritize Retrofit Not Possible Retrofits Necessary Urgent High Priority Moderate Priority Low Priority 50 The prioritization specifically considered water system operating characteristics as well as demand capacity relationships as well as redundancy. The prioritization was considered as desired targets for future seismic retrofits not mandates of work that need to be done. The Multi-Hazard Risk Assessment consultants’ recommendation for the actual design bases for seismic strengthening/retrofits to structural and non structural elements is shown in TABLE IV. The single difference between the evaluation criteria and the recommended design basis for existing MLGW facilities is life safety for non-system and minor utility buildings. It is understood that if cost of any of the proposed seismic retrofits exceeded the replacement cost of a new facility, the new replacement facility would be constructed. Additionally, if the facility is especially critical and the retrofit could not achieve the desired performance, a new replacement facility would be the preferred alternative. TABLE IV. Recommended Seismic Design Basis Existing MLGW Facilities Buildings Non-Structural Components Seismic Hazard Non-system Major Non- System Utility System Level and Minor Utility Components Components Utility Buildings Buildings Immediate 10% in 50 Years Life Safety Occupancy Life Safety Operational 2% in 50 Years Life Safety Life Safety Life Safety Operational The scope of work for the Multi-Hazard Risk Assessment did not include recommendation for new construction. However, new construction design requirements provide useful comparative tools for the evaluation of existing facilities both structural and non-structural. The consultants recommendation to MLGW were based on the IBC 2003 seismic design provision and are shown in TABLE V. 51 TABLE V. Recommended Seismic Design Basis For Construction of New Facilities Facility Type Design Seismic Building Nonstructural Importance Criteria Hazard Components Factor Non-system Life Safety Life Safety 1 Buildings IBC 2006 Two- Utility System and ASCE thirds Buildings and 7-05 of 2% Immediate Operational 1.25 and Important Non- in 50 Occupancy 1.5 System Buildings yrs. Essential Immediate Operational 1.5 Facilities Occupancy The Multi Hazard Risk Assessment consultant recommended all utility system building be given an importance of 1.25 and non-structural components an importance factor of 1.5. It was recommended that essential buildings like pumping stations be provided with an importance factor 1.50 according to the code. 52 References 1) ASCE 7-05: Minimum Design Load for Buildings and Other Structures, American Society of Civil Engineers. 2) Cramer et al (2004): The Memphis, Shelby County, Tennessee Seismic Hazard Maps, USGS Open File Report (OFR 2004-1924). 3) FEMA 356: Prestandard and Commentary for Seismic Rehabilitation of Buildings, FEMA (2000). 4) MLGW Multi-Hazard Risk Assessment, Seismic Performance Objectives, March 2, 2007. 5) MLGW Seismic Mitigation Plan 2003 for Earthquake Preparedness of Critical Water System Facilities. 53 Acknowledgements Quinton Clark P.E., Supervisor Water Engineering, Memphis Light, Gas and Water Division, Memphis, Tennessee. Kim Deaton, Senior Communications Specialist, Memphis Light, Gas and Water Division, Memphis, Tennessee. Jeffery Embry, P.E., Lead Distribution Engineer, Memphis Light, Gas and Water Division, Memphis, Tennessee. Kenneth A. Goettel, Ph.D., Goettel & Associates, Inc, Davis California. Richard E. Howe, P.E., R. W. Howe & Associates, PLC, Memphis Tennessee. Charles Truax, P.E., Lead Civil Engineer, Memphis Light, Gas and Water Division, Memphis, Tennessee. 54 Anti-earthquake Measures of Chiba Prefectural Waterworks Bureau Shigeru Hataya ABSTRACT The Chiba Prefectural Waterworks Bureau tackles the establishment of initial organization quickly at an earthquake, deploying the information apparatus, strengthening facilities against earthquake and the guaranty of water. In 2,006, using the e-mail function of a cellular phone, the Bureau made "Gathering Personnel System in Emergency" which will appeal automatically to personnel for gathering to offices at an earthquake. In 2,007, the Bureau will make "Damage Information Collection System" which totals automatically the damages of an earthquake. Moreover, the Bureau will install "Satellite Radio Apparatus" for disaster prevention as a more strengthening step of means of communication. In order to supply the power to the offices for power failure, the Bureau will install "Private Power Generation Equipment". In order to be able to recover the damages quickly, the Bureau cooperates with the cities and the villages in a water supply area. In addition, the Bureau concludes the support agreements with other waterworks entities and private organizations. Shigeru Hataya, Engineer, Planning Division of Engineering Department, Chiba Prefectural Waterworks Bureau, 417-24, Makuhari 5-chome, Hanamigawa-ku, Chiba-shi, Japan, 262-0032 55 １．INTRODUCTION Water supply exists as a vital lifeline supporting civic life and urban activities, charged with minimizing damage from earthquake disasters, providing immediate emergency water supply and rehabilitation. The Waterworks Bureau established its “Interim Management Plan”, its 5-year management guidelines in 2005, citing the “creating of a water service that can withstand earthquakes and other emergencies”, and is working to establish an immediate first response to emergencies, installing and enhancing information communication functions and providing water, as well as constructing facilities that can endure disasters. In 2006, the Bureau established its own Emergency Management Response Section in planning division and completed creation of “Gathering Personnel System in Emergency” calling for the automatic involvement of personnel when disasters strike. Then in 2007, the Bureau will develop “Damage Information Collection System” for automated damage estimates, and it is planning to install “Satellite Radio Apparatus” for disaster prevention and “Private Power Generation Equipment” to its offices. The Bureau is also working to strengthen its links with the cities and the villages in water supply area to ensure proper water supply and rehabilitation when disaster occurs, and is moving ahead on support arrangements with other waterworks entities and private institutions. This paper focuses on explaining new measures relevant to the “Interim Management Plan”. ２. OVERVIEW OF CHIBA PREFECTURAL WATERWORKS BUREAU The Bureau were established in Chiba Prefecture in 1934, and currently supply water to 11 cities and 2 towns mainly in the coastal areas facing Tokyo Bay, thus providing water to a population of around 2.8 million people, with a maximum daily water supply of around 1.0 million m3, making it the 3rd largest water service population-wise in Japan. The Bureau has 5 water intake facilities, 5 water purification plants and 14 water pumping stations with the water source of 85% of dependence on reservoirs along the Tone River and a total of 8,400 km of pipeline extensions (not including water service piping). ３.OVERVIEW OF EARTHQUAKE MEASURES 1) Basic Measures The Japanese Islands located in the circum-Pacific orogenic zone, is vulnerable to large-scale earthquakes at any point throughout the country each year from any sea trench or inland earthquake. 56 The Bureau is charged with strengthening earthquake resistance of facilities, establishing a deployment system, deploying a communications system and establishing an immediate emergency water supply and rehabilitation system for earthquake disaster measures based on lessons learned from the Kobe (Hanshin-Awaji) Earthquake in 1995 and the Niigata-Chuetsu Earthquake two years ago. 2) Anti-earthquake Disaster Measures System A simple systematizing of basic measures organizes measures into the 5 categories as shown in attached Figure-1. The basic system design concept is to minimize damage to water supply facilities and immediately establish a first response system at earthquake disasters. These 5 categories are illustrated below. W a te r P u rification Plants Strengthen Earthquake R e s istance of Facilities Pipeline Facilities Make Manuals Develop Inform ation Means Enhance Em ergency Activities Im p lem ent Training e Link with R e levant Institu tions k qua h Enhance Functions of Offices In s ta ll E q u ipm ent in O ffices -eart i nt saster Measures saster A C onstruct Distribution reservoirs Di Utilize Underground Water Sources Prpvide Em ergency Water Supply Install W a te r S u p p ly Equipm ent W a te r T ra n sp o rta tion System Stockpile Materials Keep Em ergency Materials Supply M easures of M aterials Figure-1 Anti-earthquake Measures System of the Bureau (1) Strengthen Earthquake Resistance of Facilities a) Promote strengthening earthquake resistance of water intake facilities, water purification plants, water pumping stations and pipelines, and establish private power 57 generation equipment for power outages. (91% of facilities earthquake resistant at present, installed private power generation equipment at all water purification plants and water pumping stations) b) Promote to make water distribution blocks smaller in order to minimize water suspended area and speed up rehabilitation activities. (Blocks from 33 to 62 by 2,010) (2) Enhance Emergency Activities a) Determine roles of emergency water supply and rehabilitation and places to gather for all personnel at earthquake disasters every year after personnel changes, note these on business card size “Personnel Dispatch Instruction Cards”, and hand these cards to all personnel. b) Make activities manual at earthquake disaster, conduct training according to the manual, check and revise manual and hone the mastery of assigned roles through earthquake disaster training. c) Promote the deployment of satellite radio apparatus for information communication with the prefecture, cities and villages in water supply area, work to maintain and expand various communications means in the Bureau such as the already-installed commercial wireless devices and satellite phones, as well as IP phones using network lines in the Bureau. Meanwhile, utilize e-mail functions of cellular phones and create an “Gathering Personnel System in Emergency ” calling for personnel to assemble immediately, develop a “Damage Information Collection System” for automated estimations of disaster information and work to enhance information communication functions. d) Strengthen links with cities and villages in water supply area, conclude support arrangements with private organizations for receiving support at disasters. (3) Enhance the Functions of Offices a) Strengthen earthquake resistance in all bureau offices which are the sites for emergency activities after earthquake and install private power generation equipment. b) Install satellite radio apparatus for disaster prevention in all offices as a reliable information means at earthquake disasters. c) Install emergency water supply tank to offices for water reservation. (4) Provide Emergency Water Supply a) Construct water distribution reservoirs in water purification plants, install emergency stop valves to water distribution reservoirs for prevention of saved water outflow. Properly maintain and manage underground water as an emergency water source. b) Install emergency water supply equipment at 5 water purification plants and 14 water 58 pumping stations. c) Establish a backup system countering damage to water purification plants, water pumping stations and main pipelines at earthquake disasters. Develop a program of automated selection of water transportation route for immediate alternate supply to back up smoothly damaged plants and pipeline by the other remained facilities. (5) Keep Emergency Materials for Rehabilitation a) Disperse and stockpile emergency materials in water purification plants and water pumping stations , and Makuhari Earthquake Response Warehouse. b) Conclude materials supply support arrangements with private organizations. ４. MAJOR CRISIS MANAGEMENT MEASURES IN INTERIM MANAGEMENT PLAN In the earthquake response system of the Bureau, major crisis management measures are being mapped out as essential measures of the Interim Management Plan, and system related measures forming the main theme of this workshop are illustrated below. (1) Create Gathering Personnel System in Emergency The most important thing in crisis management gets in contact with personnel and staffs. The concept leading to creating this system is to acquire a communication mean for ensuring contact with personnel and other staffs during earthquake disasters. The Bureau is currently focused on the remarkable spread of cellular phones around the world, which are used daily by people in Japan as a communication mean between business, home and friends, having considered its use as a communication mean during earthquake disasters using e-mail functions. This System is linked to earthquake information announced by the Japan Meteorological Agency to send e-mails immediately to personnel and other staffs from system computers before communication regulations are started, call for personnel to assemble and check on their safety. The assembling of personnel is tracked through their replies to plan mobilization of personnel for emergency activities. This system was created in December 2006, trials were completed in January 2007, and surprise training for information communication was conducted on personnel using this system in April when favorable communications results were gained. 59 Grasp real-time status of Countermeasure HQ personnel participant Earthquake Group Name Response Date/time Response Response No User Name As c . De c . Asc. De c . Asc. De c . Comment Nobunaga Planning Dept., 001 2006/12/31 0:25 Within 30 min On the way Oda General Affairs Hideyoshi Planning Dept., Immediately 002 Hashiba General Affairs 2006/12/31 0:32 Within 1 hour Mitsuhide Planning Dept., Delay in Participation 003 Akechi General Affairs 2006/12/31 0:33 Within 3 hours Screen Image Internet Weather Association Personnel Participant System Personnel’s Cell Phones Figure-2 Gathering Personnel System in Emergency (2) Create Damage Information Collection System The Bureau will create this system in 2007. Personnel and other staffs report damage information on water facilities at an earthquake using a cellular phone’s mobile communications. This system classifies these data according to region, damage type and scale, and automatically calculates the number of affected locations. Tabulated damage information is shared with the Earthquake Response Headquarters and the Forward Command Center which is useful for the planning of emergency water supply and emergency rehabilitation. (3) Deploy Satellite Radio Apparatus for Disaster Prevention Although the Bureau has already deployed a variety of communications equipment such as IP phones, commercial wireless devices and satellite phones, the satellite radio apparatus for disaster prevention is the most reliable communication equipment during disasters. The Bureau will deploy these to strengthen an information communication mean with the cities and the villages in water supply area. 4 portable satellite radio apparatus for disaster prevention were deployed in 2005, and the fixed satellite radio apparatus will be installed in all 11 command center office locations for emergency water supply in 2007. 60 Photo-1 Portable Satellite Radio Apparatus for Disaster Prevention (4) Deploy Private Power Generation Equipment Private power generation equipment will be installed in all 11 command center offices for power outages during disasters. These have been installed to 4 offices by 2006, and the remaining 7 offices will have this equipment installed in 2007. The private power generation equipment is diesel engine power which uses light oil as fuel with a power capacity of 30 KVA to 130 KVA according to the size of the office, and keeps a fuel tank for 12 hours of operations. Photo-2 Private Power Generation System 61 (5) Conclude Support Arrangements with Other Organizations a) Link with Cities and Villages in Water Supply Area In order to perform immediate, proper emergency water supply during earthquake disasters, the Bureau needs to link closely with cities and villages in water supply area, liaison and exchange information in advance; therefore, the Bureau established a Coordinating Committee with those cities and villages in water supply area in 2004 which meets yearly. This committee works to coordinate information communication systems, emergency water supply activities, press releases and other tasks during earthquake disasters. The Bureau, cities and villages recognized creating a command system and organizing specific role sharing among them for emergency water supply, when the Disaster Response Headquarters was established. The roles of the Bureau are as shown below: ○ Site water supply at water purification plants and water pumping stations ○ Water transport and supply to shelters and important institutions using water tank trucks ○ Emergency water supply using temporary water supply tap facilities Municipal mayors are charged with supplying potable water during emergencies in the “Chiba Prefecture Regional Disaster Prevention Plan”. b) Support System with Other Prefectures In the event the Bureau finds it difficult to conduct its emergency water supply and rehabilitation response on its own, the Bureau shall request assistance from other waterworks entities based on the following agreements. ○ “Mutual Disaster Assistance Agreement” with the Chiba Branch of Japan Water Works Association” ○ “Mutual Disaster Assistance Agreement" with the waterworks bureaus of Tokyo, Yokohama City, Kawasaki City and Kanagawa Prefecture c) Support System with Private Organizations The Bureau has concluded water supply disaster assistance agreements with private concerns to equip it for damage. In order to smooth out emergency activities when disasters occur, the Bureau has concluded agreements on the supply of recovery materials with the Japan Ductile Pipe Association and private materials companies, and for rehabilitation construction work with the Water Piping Construction Cooperative Society and the Construction Work Association. The Bureau has deployed a support system for disasters. 62 In particular the Bureau has concluded the “Agreement on Water Piping Rehabilitation at Disasters” with Water Piping Construction Cooperative Society on provision of support for pipeline patrol, emergency water supply and emergency rehabilitation activities by the Cooperative Society members, when seismic intensity 5 or greater earthquake occurs in the water supply area. In the event the Bureau is requested to send support to the waterworks entities of other prefectures, the Bureau can request active support on the agreement to the Water Piping Construction Cooperative Society for a wide array of tasks such as dispatching Society members in cooperation with the Bureau. ５．CONCLUSION The postwar baby-boom generation is starting to retire, and organizational downsizing is advancing along with this. Whether emergency water supply or emergency rehabilitation activities can be conducted immediately when an earthquake disaster occurs, depends on whether water supply activities and water leakage repair work can be performed in everyday work on water suspension and colored water countermeasures. As experience and technology including emergency responses are passed down to the next generation, the younger generations must be taught through everyday work and earthquake disaster training in order to ensure onsite responses, while softening water transportation system to back up accumulating past accident examples must be created, support systems for supplementing the lack of experience of younger people established, earthquake resistance strengthened in order to minimize damage to facilities at an earthquake, water distribution blocks made to prevent expansion of pipeline damage and accelerate rehabilitation, and backup facilities deployed countering main facilities damage. A system from both soft and hard aspects must be established to work on preventive measures against snowballing damage and the effects therein. In the event the damage incurred exceeds the response limit of the Bureau, immediate and intensive emergency water supply and emergency rehabilitation activities should be conducted through the support received from other municipal waterworks entities and private organizations. The Bureau makes efforts to install communications, power supply means and drinking water equipments to offices in order to display many functions as a command center at an earthquake. 63 64 A New Solution for a Hydraulic Fill Dam - The Case of San Pablo Dam Elizabeth Z. Bialek1, Fred M. Starr2, and Atta B. Yiadom3 ABSTRACT San Pablo Dam is a water supply reservoir owned by the East Bay Municipal Utility District (EBMUD). The dam was constructed between 1917 and 1921 and is composed entirely of hydraulic fill with a clay “puddle” core. The materials for the fill were obtained from the abutments and consisted of mudstones, siltstones, sandstones and shales containing a considerable amount of clayey materials. The dam is 170 feet high with the crest at elevation 329 feet and the spillway at elevation 314 feet providing 15 feet of freeboard. Previous seismic evaluations had indicated that improvements were necessary, and therefore buttress fills at the downstream and upstream slopes were constructed. Placement of a buttress fill at the upstream slope of the dam in 1980 has increased the dam width from 50 feet to 125 feet. The dam has a crest length of 1200 feet. In 2002, the State of California Division of Safety of Dams (DSOD) requested the District to again reanalyze the seismic stability of San Pablo Dam, among other dams owned by EBMUD. The result of the analysis concluded that the dam could be subjected to large deformations due the liquefaction susceptibility of the foundation and embankment materials. Several alternatives were evaluated for the seismic retrofit of the dam including removal and replacement of large portions of the liquefiable materials. Preferred alternatives that would allow the continued use of the reservoir were given higher priority. These included in-place improvement of a portion of the foundation material and a buttress fill at the downstream toe to limit seismic deformations. In order to ensure a continued water supply and less disruption to the environment and recreation, in-place improvement techniques were selected. Analyses are under way to finalize design of an upgrade, with improvements to the hydraulic fill dam foundation through cement deep soil mixing (CDSM) or slurry walls using cement medium strength material (CMSM). INTRODUCTION San Pablo Dam is a water supply reservoir owned by the East Bay Municipal Utility District (EBMUD). EBMUD is a publicly owned utility formed under the Municipal Utility District Act passed by the California Legislature in 1921. The Act permits formation of multipurpose government agencies to provide public services on a regional basis. In accordance with the Act's provisions, voters in the area created EBMUD in 1923 to provide water service. EBMUD 1. Engineering Manager, East Bay Municipal Utility District, Oakland, California 2. Senior Civil Engineer, East Bay Municipal Utility District, Oakland, California 3. Associate Civil Engineer, East Bay Municipal Utility District, Oakland, California 65 supplies water to about 1.3 million people in parts of Alameda and Contra Costa counties on the eastern side of San Francisco Bay in Northern California. EBMUD’s primary water source is the Mokelumne River. The Mokelumne River watershed is on the west slope of the Sierra Nevada and is generally contained within national forest or other undeveloped lands. The water is stored at Pardee and Camanche Reservoirs in the foothills of the Sierra Nevada mountains in eastern California. Water from Pardee Reservoir is carried 90 miles by three aqueducts, and the portion of the water not immediately treated is stored in local terminal reservoirs, including San Pablo Reservoir. The terminal reservoirs provide emergency storage which would be critical in case of a problem with the aqueducts. These reservoirs are also needed to meet normal summertime demands, when the Pardee supply by itself is insufficient. EBMUD operates 6 water treatment plants, has over 4,000 miles of potable (treated water) distribution and transmission pipes, 13 local tunnels, 175 potable water reservoirs, and 130 pumping plants to constitute the backbone of the water system. EBMUD’s service area and water supply is shown in the figure below: FIGURE 1: EBMUD Service Area and Water Supply 66 SAN PABLO DAM AND RESERVOIR San Pablo Dam has a capacity of 38,600 acre-feet, and the reservoir has a surface area of 834 acres and a shoreline length of about 14 miles. The reservoir serves four water supply functions: emergency standby storage, regulation of Mokelumne water supply, conservation/storage of local runoff and raw water supply for two water treatment plants. In addition, it provides flood control benefits to the downstream community and provides recreation opportunities such as fishing, boating, picnicking, nature study, horse riding, and hiking. A view is shown below in Figure 2: FIGURE 2: View of San Pablo Dam and Reservoir The dam was constructed on San Pablo Creek between 1917 and 1921, prior to the formation of EBMUD, by the People’s Water Company. It was formed almost entirely as a hydraulic fill with a clay “puddle” core. The materials for the fill were obtained from the abutments and consisted of mudstones, siltstones, sandstones and shales containing a considerable amount of clayey materials. Using hydraulic jets, the materials were washed from the hills, transported hydraulically to the deposition site via open flume viaducts. (Figure 3 shows the construction of the dam.) The deposits were sloped to facilitate the migration of the finer-grained sediments toward the middle of the embankment to form the puddle core for the dam. A cutoff trench, approximately 10 feet wide and centered about 50 feet downstream of the embankment centerline, was excavated to bedrock and backfilled with clayey material before the hydraulic fill process started. The embankments were founded on alluvial sediments and colluvial materials associated with San Pablo Creek drainage and landslide materials along the creek banks. The alluvial deposits range up to 100 feet thick in some areas. 67 FIGURE 3: Construction of San Pablo Dam The dam is 170 feet high with the crest at elevation 329 feet and the spillway at elevation 314 feet providing 15 feet of freeboard. Placement of a buttress fill at the upstream slope of the dam in 1979 has increased the dam width from 50 feet to 125 feet. The dam has a crest length of 1200 feet. The upstream has a slope of 4 horizontal to 1 vertical. The downstream has a slope of about 2 horizontal to 1 vertical. As a result of seismic stability evaluations over the years, a buttress fill was placed at the downstream toe in 1967 and the core of the dam was extended about 3 feet above the spillway elevation, and an upstream buttress was placed in 1979. A typical dam cross section is shown in Figure 4. FIGURE 4: San Pablo Dam Typical Cross Section 68 SEISMIC SETTING San Pablo Dam is in the seismically active area along the North American-Pacific plate boundary where the San Andreas Fault zone acts as the active transform system of shears between the plates. Significant active faults that could produce ground shaking to potentially affect the reservoir include the San Andreas, Hayward, Calaveras, Concord, and Mount Diablo (thrust) faults. The closest fault is the Hayward Fault, which lies less than 2 miles (3 kilometers) west of the site, and is capable of producing a Maximum Credible Earthquake (MCE) of moment magnitude 7.25. The other major fault is the San Andreas Fault, which lies about 20 miles to the west, and is capable of an MCE of moment magnitude 8. FIGURE 5: Map of Regional Seismicity (USGS 2002) San Pablo Dam In 2002, the Working Group on California Earthquake Probabilities under the auspices of the United States Geological Survey concluded that there is a 62 percent probability of a strong earthquake (magnitude greater than 6.7) striking the greater San Francisco Bay Region over the next 30 years (2003-2032). As a result of this information and in response to the ever evolving field of earthquake engineering, EBMUD has completed several seismic studies of its dams. The history of seismic evaluations of San Pablo Dam is outlined in the next section. HISTORY OF SEISMIC STUDIES EBMUD started to review the seismic design of its embankment dams in the 1960s. Following subsurface investigations and laboratory testing, pseudo-static analyses of the dam by Shannon and Wilson Consultants concluded that the dam was essentially stable but recommended that the impervious puddle core be extended at least 3 feet above the maximum water level and that a buttress fill be placed at the downstream face of the dam to improve slope stability of the toe. 69 The recommendations were constructed in 1967. The buttress fill is 35 feet high to elevation 235 feet and about 150 feet wide at the top. Following the 1971 San Fernando earthquake, the District again performed seismic analyses of its major embankment dams including San Pablo Dam. The analysis performed by Woodward- Lundgren and Associates concluded that substantial settlement and lateral deformation of the upstream slope of the dam could occur during a major seismic event. The analysis and conclusions at that time relied primarily on laboratory cyclic triaxial testing measurements to determine the seismic strength of the materials to withstand the earthquake loading. The report recommended that an earthfill buttress be placed on the upstream slope of the dam to increase the seismic stability. The reservoir was drained and the upstream buttress was constructed and keyed into bedrock in 1980. In 2002, the State of California Division of Safety of Dams (DSOD) requested the District to again reanalyze the seismic stability of San Pablo Dam, along with other dams owned by EBMUD. The request was driven by advances in knowledge of earthquake ground motions, current field investigation methodologies to characterize the materials that comprise the dam, the nature of the dam construction (in this case, being a hydraulic fill dam), and by the proximity of the dam with respect to major seismic sources (Hayward and San Andreas Faults). As a result of this request, an updated seismic study was completed in 2004. 2004 SEISMIC ANALYSES AND ALTERNATIVES The 2004 seismic analyses assumed that the hydraulic shells and the alluvium/colluvium foundation soils would liquefy (a common problem in typical hydraulic fill dams), resulting in an estimated 35 feet of maximum deformation for the downstream slopes. The improvements constructed in 1980 at the upstream slopes limited upstream deformations to less than 2 feet. EBMUD immediately lowered the maximum reservoir level by 20 feet to provide at least 35 feet of freeboard and embarked on a plan to evaluate alternatives to strengthen the dam. The results of the 2004 seismic stability analyses are shown below: FIGURE 6: 2004 Seismic Stability Analyses Results 70 The alternatives evaluated included removal and replacement of much of the downstream embankment and foundation soils; several combinations of in-place improvement of the foundation soils and building larger downstream buttress fill to replace the existing smaller downstream buttress. The removal and replacement option would have required the EBMUD to build a 5-mile long temporary pipeline to provide uninterrupted water service to its customers. The pipeline cost would also substantially increase the project cost and add to environmental impacts along the pipeline route. FIGURE 7: San Pablo Dam Replacement Alternative Existing Outline Reservoir Level Existing Embankment Rebuilt Embankment Foundation Alluvium EBMUD decided to focus on alternatives that would allow the reservoir to be operational while constructing the improvements. This way, some level of water supply could be maintained, and impacts to the environment and recreation could be minimized. The selected alternative to improving the hydraulic fill dam built on a very thick liquefiable alluvium/colluvium included the in-place improvement of a section of the foundation soils, and building a larger buttress fill to confine the hydraulic fill shell zone at the downstream end. The larger buttress fill was designed to confine and resist slope movement of the liquefied shell materials. FIGURE 8: Preferred Alternative: In-Place Ground Improvement of Foundation Alluvium Existing Outline Reservoir Level Proposed Buttress Existing Embankment In-place Improvement Foundation Alluvium Zone The in-place improvement technique considered during the conceptual design phase is a cement deep soil mixing (CDSM) method. The foundation soils will be improved by mixing in-place of the foundation soils with cement grout using large (3- to 5-foot-diameter) mixing augers. The augers are equipped with paddles along the shafts and grout injection ports at the tips. As the augers are advanced into the soil, cement grout is pumped through the hollow stem of the shafts and injected into the soil at the shaft tips. After withdrawal of the augers, overlapping soil- cement columns remain in the ground. The improved columns will not be susceptible to liquefaction and there will be an increase in the shear strength of the improved soils. In this way, the foundation soils can be improved in place rather than replaced. 71 The photo below shows typical CDSM construction equipment, which was used for the pilot testing at San Pablo.. FIGURE 9: Typical CDSM Equipment 2006 SUPPLEMENTAL STUDIES AND DESIGN OF UPGRADES Once the in-place improvement alternative was selected, final design began in 2006. Supplemental investigations were conducted as part of the effort to complete the design details. Supplemental subsurface investigations using 1) rotary wash test borings with Shelby and Pitcher Barrel samplers and Standard Penetration test soundings, 2) cone penetrometer soundings, and 3) laboratory index tests, showed that the hydraulic fill materials were not susceptible to liquefaction and were in fact very clayey due to the sources of the fill. Typical hydraulic fill dams consist of loosely deposited granular materials. However, this was not the case for San Pablo Dam. The surrounding native soils and soft rock materials are clayey in nature, and thus although hydraulically placed, were fundamentally fine-grained soils. Because of the source of the material, the embankment shell materials consist of over-consolidated clayey soils that over time have become further compacted. This was verified by visual inspection of the samples 72 taken during the most recent investigation and further validated by strength and index testing. Furthermore, a seepage analysis backed by field permeability tests confirmed that the shell zones have very low permeabilities consistent with their clayey nature. The current study also investigated the condition of the foundation soils. The embankment is underlain by alluvium and colluvium up to 100 feet thick. The alluvium/colluvium is composed of both fine-grained and coarse-grained zones that will behave differently under seismic loading. The fine-grained zones, which represent a large portion of the soils underlying the dam, have a low potential for liquefaction. However, the coarse-grained portion, which represents a smaller portion of the soil underlying the dam, will likely be subject to pore-pressure increases and liquefaction during seismic loading. Both the 2004 and 2006 analyses concluded that while most of these soils were fine-grained and not susceptible to liquefaction, there were enough liquefaction susceptible zones that required a parametric analysis treating the alluvium/colluvium as potentially liquefiable. The seepage analysis results also showed that the alluvium/colluvium in general has high permeability and that the coarse-grained zones may be continuous. Based on these findings, the 2006 analyses showed lower downstream deformation than the previous analysis and the conclusion was that there was no need for a much larger buttress fill as initially designed to confine liquefiable zones within the shell. The exact size of the new buttress fill is now being optimized. Again, it will be founded on alluvium that has been improved using in-place foundation improvement methods. Although the foundation materials do not have the wide-spread liquefaction potential that was previously assumed, they represent heterogeneous native materials that would ordinarily be removed in modern dam construction. Therefore, the alluvium soils we be improved to more conservatively prevent downstream lateral spreading of the liquefiable zones within the rest of the alluvium and also limit dam crest deformations. During final design, two in-place methods emerged as being most suitable for the existing foundation soils. The two methods are: The CDSM method identified during the conceptual design phase (described previously) and cement medium strength material (CMSM) improvement method. CMSM uses the slurry trench method to build walls within the alluvium/colluvium. Vertical walls are first excavated to the design depth by using bentonite slurry mixture to support the trench walls and to prevent movement of groundwater into the trench. CMSM backfill is a lean ready-mix concrete that contains chemical admixtures to modify performance properties of flow, set, permeability and strength and is tremied into the trench to form a wall. This method allows better control of the strength of the wall. To evaluate the actual performance of each method and to more reliably estimate the final in-situ strength of the improved soils, pilot tests of the methods were performed during the design phase. The CDSM pilot test consisted of using 2 different cement factors (weight of cement per volume of treated material) and water to cement ratios to construct several wall sections. 73 FIGURE 10: San Pablo Dam CDSM Test Section The CMSM pilot test consisted of constructing one wall section to obtain a 28-day mix compressive strength of at least 600 psi. Both methods were expected to penetrate at least 3 feet into the bedrock (with depths ranging from 50 to about 100 feet). The drill rig for the CDSM method had no difficulty in reaching the 3 feet embedment. The backhoe for the CMSM method was able to penetrate 2 feet into bedrock before reaching refusal. The CDSM columns and the CMSM walls were cored full depth to confirm adequate improvement in the alluvium/colluvium and bedrock. Cores are being stored to test for their 28-day and 56-day strengths (results not available at the time of writing this paper). 74 FIGURE 11: San Pablo Dam CMSM Slurry Trench Test Section NEXT STEPS The results of the pilot tests will help optimize the foundation improvement design in terms of CDSM column layout and CMSM wall spacing and overall size of the improvement zone. The buttress fill will be supported by the improved alluvium/colluvium and will be designed to be high enough to limit shallow slope deformations in the hydraulic fill. It is anticipated that final design will be completed by the Fall of 2007. Project construction is scheduled for the Spring of 2008 and will continue until 2010. 75 76 MANUAL FOR IMPROVEMENT OF OVER AGED RESERVOIRS WITH STEEL PLATE Nobuhiro Hasegawa, Takahiro Yabuguchi, Toshio Imai ABSTRACT The publication of the “Manual for improvement of over aged reservoirs with steel plate” 1)in Japan is a result of a joint research by the Japan Water Works Association (JWWA) and the Japan Water Steel Pipe Association (WSP). In recent years, it is becoming more important to carry out proper maintenance work on a water supply system which requires stability and continuity for operational management. Most water supply systems in Japan that were constructed and/or extended in the 1960’s are now in the stage of reconstruction, rehabilitation or repair. Therefore, many Waterworks Bureaus are doing their best to prolong the life of their respective water supply systems with minimum cost and without stopping the daily supply of water. Many reservoirs such as sedimentation basin, filter, pure water tanks in water purification plants and distributing reservoirs in water supply areas are recognized as key facilities in a water supply system. These key facilities however are over age such that rehabilitation or reconstruction is needed. If seismic assessment is conducted on these systems, many facilities might be retrofitted or reinforced to comply with seismic requirements. Several methods to improve reservoirs’ performance with steel plate are introduced in this manual. This is a prospective technology to improve the resistance to earthquakes and to prolong the life of deteriorated facilities in the near future. This report summarizes the manual for maintenance, investigation, and diagnosis with typical examples of improvement (repair, rehabilitation, etc.) methods for over aged reservoirs. ______Nobuhiro Hasegawa, Pipeline Engineer, Water Pipeline Department, JFE Engineering Corporation, 2-1 Suehiro, Tsurumi-ku, Yokohama, Japan 230-8611 ([email protected]) Takahiro Yabuguchi, Pipeline Engineer, Water Pipeline Department, JFE Engineering Corporation, 2-1 Suehiro, Tsurumi-ku, Yokohama, Japan 230-8611 ([email protected]) Toshio Imai, Manager, Water Pipeline Department, JFE Engineering Corporation, 2-1 Suehiro, Tsurumi-ku, Yokohama, Japan 230-8611 ([email protected]) 77 1. BACKGROUND 1.1 The state of aqueduct facilities in Japan In June 2004, Water Supply Division, Health Service Bureau, Ministry of Health, Labor and Welfare came out “Waterworks Vision”, which suggests the policy for what the Japanese water supply services in the future should be. Among the measure goals which the water supply systems should be achieved in “Waterworks Vision”, main issues concerning about key facilities, they are located at upper positions in the water supply systems and also very influential in the case of disaster, such as sedimentation basin, filter, treated water reservoir and service reservoir are as follows; 1) Promoting appropriate renewal of waterworks facilities, and ratio of deterioration facilities, which need renewal at once, should be zero. 2) Ratio of earthquake-resistant facilities among key facilities such as the filter and the purification plant should be 100%. 3) Especially, they should be achieved as soon as possible in the area that the serious effect of “Tonankai Earthquake” is estimated. 4) Target period of above issues makes 10 years in general. Although, many of these reservoirs constructed in 1960’s are Pre-Stressed Concrete (PC) or Reinforced Concrete (RC) and became too old, renewal of these facilities are not carried out because of the financial aspects. As the result, many of water supply systems holds serious problems such as the decrease of safety against disaster like earthquake and increase of maintenance cost for the deteriorated facilities. Below, example of the troubles that accompanies the deterioration of the reservoirs is shown. Figure 1 shows the example of water leak from crack and Figure 2 shows the example of the concrete exfoliation due to the corrosion of the reinforcing steel rod in at the ceiling. As these examples, structural strength of concrete reservoir is gradually decreasing with the crack initiation and the corrosion of reinforcing rods. Figure 1. Water leak from crack Figure 2. The corrosion of the reinforcing steel rod The Japan Water Steel Pipe Association (WSP) executed the questionnaire survey result vis-à-vis the domestic water works utilities, shown the Figure 3 Among 160 reservoirs as subjects of this survey, the facilities that elapse 40 years and more after constructed is entire 1/3, the facilities that elapse 30 years and more is entire 2/3, then it may be inferred that most of reservoirs are in severe 78 situation with deterioration. In addition, the utilities, which are worried about leak of water because of deterioration, are 32% and the utilities that fear seismic performance are entire 56%. 1.2 Purpose of manual compilation As description above, many of the reservoirs for the water supply in our country are deteriorating, in spite into either many water works utilities are feeling insecurity in seismic performance of them, reconstruction have not progressed because of the restriction of public finance. It is really important to improve deteriorated water supply facilities suitably as soon as possible to keep their adequate performance and safety for from the viewpoint of “guaranty of stable water supply”, that is a mission of water supply utilities, simultaneously, it is useful for decreasing of life cycle cost (LCC) too. Then, JWWA and WSP made a collaborative research about this theme. The results of this research were collected and published as the manual that contains maintenance method, investigation method and evaluation method of the deteriorated reservoirs. Furthermore, this manual contains improvement method with the steel plate that is the most familiar structural material for us. 1.3 Merits of the improvement with using the steel plate Various materials and construction methods are utilized as a rehabilitation method and/or improvement method for the concrete structure. However, the prevention from water leak and the high seismic performance are required for the reservoirs originally. Therefore, we paid attention to the steel plate that is most familiar for us as the material for the improvement of the deteriorated reservoirs. Merits in utilization of the steel plate are as follows; 1)Superior toughness and seismic performance can be obtained in the construction of reservoir because steel works easily. 2)Because it is assembled with welding, high water tightness is guaranteed. 3)There is superior spatial guaranty characteristic in inside and outside the reservoir that can make the component thickness thin in comparison with the concrete and such. 4) By using the stainless steel, both maintenance free conversion and reduction of LCC are possible. 55 50 45 40 35 30 25 Number 20 15 10 5 0 100 90 80 70 60 50 40 30 20 10 0 (1905) (1915) (1925) (1935) (1945) (1955) (1965) (1975) (1985) (1995) (2005) The number of the aging CE （ ） Figure 3. Distribution of the number of the aging of the reservoirs 79 Material Shape and cell number Steel 5 cylindrical PC (single-cell) 35 38 Rectangle RC Rectangle 115 (multi-cell) 95 (single –cell) 22 Structure classification Yes 32％ No Yes No 44％ 56％ 68％ The concern of the leak of water The concern of the leak of water (When a big earthquake occurs) Figure 4. The present conditions of the reservoirs 1.4 Definition of terminology Main terminologies used in this manual are rearranged in Table 1. The subject “improvement” is used as the general term that includes repair, rehabilitation and renewal. The improvement method should be selected according to the structural condition and other factors. 80 Table 1. Definition of main terminologies Terminology Definition Functional evaluation To appraise the functional state of the structure. Repair To recover or improve the resistance against the deterioration of the structure. Rehabilitation To recover or improve the structural strength and the stiffness of the structure. Renewal To re-install higher quality with abolishing function of the facilities or structure which decrease the performance. Improvement General term including of repair, rehabilitation and renewal. Repair To recover until the proper condition or the original form with adding the hand to the components which decrease the performance. Below, it introduces concerning the contents of the manual, which is the research result. 2. MAINTENANCE AND EVALUATION OF RESERVOIRS 2.1 Maintenance procedure of reservoirs Figure 5 shows the flow diagram of the Check maintenance procedure for the reservoirs. Maintenance work is classified into the daily no Disorder（Leak, maintenance work and the improvement Transformation） activity. In the former work, it includes a yes Daily maintenance work periodic inspection, which is previously Is maintenance yes planed with proper period and contents, and possible by repair? cause investigation and repair when it is Repair recognized that there is slight abnormal no phenomenon such as minute leak of water etc. no Is there concern of the In the latter work, it is the activity which functional decline? should execute when remarkable change such yes as an occurrence of large crack or Setting of aim Function diagnosis deformation of the structure etc. by periodic Improvement activity inspection. It includes (1) the evaluation of the facility with investigation in detail and no Does the diagnosis result examination about structural strength, (2) the need improvement? design and planning of some measures based yes on the required function and level of the END Improvement facility, LCC, and their possibilities, (3) improvement with appropriate method after Figure 5. Maintenance procedure comparing plural alternatives. With this manual we have described in detail concerning especially latter works. 2.2 Evaluation of reservoirs’ performance 1) Purpose of evaluation 81 Evaluation of reservoirs’ performance is the activity that has the purpose to judge if it needs the improvement or not. It can classify the standard evaluation method and the detailed investigation method. At the time of the execution of the evaluation, it is necessary to make clear the target level of structural function and to give coherence in maintenance. 2) Standard evaluation and detailed investigation With this manual, the method is based on "Renewal Guide for Water Facilities" 2) of the JWWA as standard diagnostics. Eq.-1 can be used to appraise the physical condition of distributing reservoir. The diagnostic result with the score is shown in Table 2. ×××××= 6/1 ( NY σ SSSSSSS CSL ) (Eq-1) Where, S : Physical appraisal score of the structure. SY: Converted score from the degree of decrepitude of the structure. SN: Carbonation score of the concrete. Sσ: Compression strength score of the concrete. SL: Converted score from the reservoir’s leak ratio. SS: Converted score from the seismic intensity of facility. SC: Capacity score of the reservoir. Table 2. Physical appraisal score and appraisal contents Score Appraisal contents 76 - 100 Good condition. 51 - 75 Allowable condition. However, it is necessary to improve and to strengthen the weak point. 26 - 50 Bad condition. Deliberate renewal is necessary. 0 - 15 Terrible condition. It is necessary to renew urgently. On the other hand, detailed investigation is the activity when it is necessary to get more information to decide the measure or it is obvious that improvement is necessary from the results of standard evaluation. It is constituted from the individual jobs such as preliminary investigation, simple deterioration diagnosis, cause presumption of deterioration, estimation of seismic performance and evaluation for required efficiency. The results of these activities are not only used for the final decision about the necessity of improvement but also used for the selection of the best measure for improvement. In this report, only the seismic evaluation is described in detail and the others are neglected. 2.3 Seismic evaluation of the reservoir Seismic evaluation of the reservoir is done as a part of performance evaluation. Seismic evaluation has 2 types; one is the simple method that is executed as a part of standard evaluation, which is based on the information that the water works utilities have generally, and the other one is the evaluation which is based on the result of detailed investigation of deterioration and numerical verification of seismic strength. In this manual, the former method is called “Simple seismic evaluation”, and the latter is called “Detailed seismic evaluation” 82 Simple seismic evaluation estimates the value of seismic performance of the facilities relatively or conceptually, it cannot estimate the value of whether the whole and the component structure of the individual facility possessing some seismic performance or whether some part how strength it is insufficient. Detailed seismic evaluation is executed in such case. 1) Simple seismic evaluation of individual facility Concerning the simple seismic evaluation procedure of the individual facility, it conforms to the method stipulated with "Renewal Guide for Water Facilities" of JWWA. With this method, we can easily classify the seismic performance level of the facility using the degree of seismic score (SS) according to its seismic design level shown in Table 3. Table 3. Degree of seismic quantitative evaluation method of facilities Level of seismic design Degree of seismic score (SS) (point) Almost no seismic design is considered. 25 Seismic design is executed as the seismic level corresponds to 50 the horizontal seismic coefficient 0.2. Seismic design is executed as the seismic level corresponds to 75 ground motion level 1, criticality rank A Seismic design is executed as the seismic level corresponds to 100 ground motion level 2, criticality rank A * The seismic performance level of the facility is evaluated as a score on a maximum scale of 100 points. 2) Detailed seismic evaluation of individual facility As for detailed seismic evaluation of the individual facility, it executes seismic verification that conforms to the seismic design method shown by “Seismic Design Code of Water Facilities” (JWWA) 4) from the investigated data such as ground condition, material characteristic and structural details. Regardless of seismic design method, it is required that the facility would sustain no damage against the ground motion level 1. On the other hand, against the ground motion level 2, the facility should keep its performance and the damage on the facility should be restricted as a slight level. a) The method due to seismic coefficient method The seismic verification with seismic coefficient method is applied to the reservoir on the ground. In this method, it seeks horizontal seismic intensity for design in ground motion level 1 from standard horizontal seismic intensity at the center of structure and correction coefficient classified by area. In addition, it calculates horizontal seismic intensity for design in ground motion level 2 from standard horizontal seismic intensity at the center of structure, natural period of ground and structural property coefficient in ground motion level 2. As for each ground motion level 1 and 2, it calculates earthquake dynamic water pressure and force of inertia according to horizontal seismic intensity, and it executes verification for stress in each element and for possibility of reservoir’s overturning. b) The method due to seismic deformation method The seismic verification with seismic deformation method is applied for the underground reservoir. With the method due to seismic deformation method, it seeks the ground horizontal displacement amplitude in ground motion level 1 from the response spectrum of velocity, natural 83 period of surface ground, horizontal seismic intensity for design of the design basis surface and thickness of surface ground in ground motion level 1. In addition, it seeks the ground horizontal displacement amplitude in ground motion level 2 from the response spectrum of velocity, natural period of surface ground and thickness of surface ground in ground motion level 2. Seismic strength of the reservoir is evaluated for both ground motion level 1 and level 2, by using structural model shown in Figure 6. Force of inertia Force of inertia Ground spring Displacement amplitude (forced displacement) Hydrostatic pressure Dynamic water pressure Figure 6. model of seismic coefficient method Figure 7. model of seismic deformation method The structural strength of reservoir’s foundation also should be checked. For the structural evaluation of reservoir’s foundation, it is necessary to make a structural analysis with referring “Seismic Design Code for Water facilities”(JWWA) based on the data such as the type of foundation and the property of surrounding ground. In addition, when the improvement of reservoir is done with using the steel plate, the dead load to act the foundation increases slightly. It is a rare case that the additional load makes a problem, because the increase amount of load is very small in comparison with the load of existing reservoir and containing water. However, according to the result of verification of the foundation, when it becomes insufficient, it needs to examine the rehabilitation measure of the foundation as soil improvement or additional piling. 2.4 Final decision for measure of improvement The final decision about the necessity of reservoirs’ improvement should be executed based on the consideration about several factors on basis of viewpoint as waterworks utilities such as the balance of the total water supply system, the improvement priority of this facility, business environment, cost performance of improvement and social needs. The way of thinking about the comprehensive decision is introduced in “Renewal Guide for Waterworks Facilities” (JWWA). The summary of this technique is shown in Table 4. After the final decision that the improvement is necessary for the facility is made, the selection of the optimum improvement method should be executed. In order to select the optimum method, confirmation of the purpose of improvement and establishment of the target level are necessary at first phase. And then, planning of several alternatives for improvement should be executed. The final selection of the best improvement method is executed by comparing of these alternatives from the view of cost performance and their possibility. There are many alternatives as the improvement method from the view of using materials. For example, steel plates, cement mortar, resin mortar, rubber and paint are available for improvement of the reservoir. In this manual, we picked up the large-scale improvement methods with steel because of the aforementioned reason. 84 Table 4 Comprehensive decision technique Renewal Guide for Waterworks Facilities (JWWA) Appraisal of facility renewal is to examine the positioning of renewal as a judgment of Basis necessity of renewal due to the physical characteristic of waterworks facilities and as waterworks utilities. To advance renewal works, it is necessary to make standard of measuring effect and Additional estimating criticality appraisal after grasping what the consumers want, what is important factors for they think and whether they are satisfied vis-à-vis waterworks utilities in advance. decision Priority It does the sequencing of renewal by estimating and deciding “the importance of the waterworks facilities” and “the effect of renewal” etc, based on these items of information. Comprehensive physical appraisal score（point） 100 Good condition XII XI X 75 Necessary of reinforcement with improving the weak point IX VIII VII 50 Bad condition. VI V IV Deliberate renewal is necessary. 25 Terrible condition. III II I It is necessary to renew urgently. 0 30 70 100 small middle big Appraisal criticality（point） * The Arabic figureures show priority 1)Appraisal as an aqueduct business ・To decide criticality of the aqueduct facility which becomes the renewal object from the table ・To decide Fixed quantity appraisal renewal precedence from the Figureure ・To examine alternative characteristic of the facility Procedure of ・To examine he effect of renewal front and back the final 2)Solution of technical problem decision ・To examine water supply guaranty circumstance during renewal period ・To examine renewal method 3)To examine problem with respect to public finance 4)To examine correspondence as an organization 5)To examine harmony as an aqueduct business Over-all judgment renewal with above. 3． THE IMPROVEMENT OF THE RESERVOIRS WITH STEEL PLATE Table 5 shows several improvement methods with steel plate. 85 Table 5. Measures and improvement methods with steel plate Kind of measures Purpose Improvement method Repair Repair of leakage Coating with stainless steel plate: Type-1 Above + Coating with stainless steel plate: Deterrence against deterioration Type-2 Rehabilitation Above + Coating with stainless steel plate: Seismic reinforcement Type-3 Renewal Above + Pluralization of the reservoir Tank in tank method Tank out tank method Repair of leakage, Seismic reinforcement Donut tank method & Increasing capacity Replacement 1) Steel tank 2) Stainless steel tank 3.1 Coating with stainless steel plate Figure 8 shows an example of improvement method by coating with stainless steel plate from the inside of the reservoir. There are 3 types of improvement methods as shown in Table 5, suitable type can be selected as the condition of the reservoir, the purpose of improvement and the financial condition of waterworks utilities, etc. This method is very economical and also ecological because it arrows re-use of the existing reservoir. Furthermore, the improved structure requires minimum maintenance by coating with stainless steel, and it would be able to reduce the maintenance cost in the future. 1）Coating with stainless steel plate:Type-1 This method, shown in Figure 8 is applied for repair of the reservoir. Purpose of improvement with this method is to prevent water leakage from existing reservoir. Structural strength depends on the existing reservoir, because the effect of reinforcement is not expected with this method. As shown in Figure 9, the thin stainless steel plates are fixed by pins of the machine casting in the existing service reservoir inside and are joined along superposition point of stainless steel plate by fillet welding. In addition, the casting pin zone realizes security of the water tightness and adaptation to the heat shrinkage because fillet welds cover cap circumference in a stainless steel pin cap. Gas Area Fillet Weld Liquid Area Stainless Pin + Pin Cap Thin Stainless Plate 86 Figure 8. Example of Type-1 Figure 9. Example of Type-1 2）Coating with stainless steel plate:Type-2 Gas Area It is a repair method aimed for prevention of leakage from the inside and prevention of subsurface water invasion from the outside. The structural strength depends on an existing service reservoir as same as Type-1. As shown in Figure 10, some Anchor Bolt stainless steel beams are installed with anchor bolts, then arc-shaped thin stainless steel plates are joined together, and Installation Plate mortar fills up a gap with the existing service reservoir inner wall. Liquid Area Improved reservoir with this method has the structural strength against the water pressure from inside and outside of reservoir. Figure 10. Example of Type-2 3）Coating with stainless steel plate:Type-3 Gas Area It is a rehabilitation method aimed for improving the seismic Stainless Plate performance and water toughness of the reservoir. It realizes Stud Bolt prevention of leakage from the inside and the prevention of the Tipping subsurface water invasion from the outside, and improvement of Enlargement Concrete Liquid Area structural strength of the reservoir. As shown in Figure 11, this Existing Concrete method forms Steel Concrete Composite Structures by installing concrete in the stainless steel plates which installed a stud dowel in inside gap, after having done tipping of the deterioration concrete layer of the existing service reservoir inside. In this case, thickness of stainless steel plates should be increased in Figure 11. Example of Type-3 comparison with the repair methods above. 3.2 Renewal of the reservoir There are several ways to renew the reservoir with steel according to the purpose of improvement. Figure 12 shows an example of “Tank in tank” method that is to set up a new reservoir with steel or stainless steel in which contacts with existing reservoirs’ sidewall for improving the seismic performance and water-toughness. On the other hand, Figure 13 shows an example of “Tank out tank” method that is to set up a new reservoir with steel Figure 12. Tank in tank method outside of existing reservoir in order to improve it’s seismic performance. Figure 14 also shows a kind of “Tank out tank” method, called “Donut tank” method that is to set up a new reservoir with steel increase it’s capacity and improve security to be duplicated. 87 Figure 13. Tank out tank method Adopting these renewal methods is very profitable because they are not only ecological but also economical. With these methods, it is not necessary to prepare new construction yard and it is able to re-use the existing reservoir, therefore no cost concerning about demolishing existing reservoir and disposal of construction waste is needed. 3.3 Reinstallation of the reservoir In the case of reinstallation, steel or stainless steel is suitable for the use of reservoirs’ construction because of its characteristics. With using these materials, it is able to construct a new reservoir that is superior in Figure 14. Donut tank method seismic performance and durability. 4. CONCLUSION In this report, “Manual for improvement of over aged reservoirs with steel plate” as the results of the collaborative research by JWWA and WSP are summarized. Improvement method of the reservoirs by using steel plate is one of the technologies that apply to many existing facilities because of the increasing tendency about improvement of seismic performance of existing reservoirs and actualization of demand of improvement of deterioration facilities. We hope this manual be utilized for the maintenance works in the waterworks utilities and be helpful for effective improvement of the deteriorated reservoirs to extend their life time and to protect against the earthquake which should come in the future. REFERENCES 1) Japan Water Works Association, 2006, “Manual for improvement of over aged reservoirs with steel plate” 2) Japan Water Works Association, 2006, Maintenance Guide for Waterworks Facilities. 3) Japan Water Works Association, 2005, Renewal Guide for Waterworks Facilities. 4) Japan Water Works Association, 1997, Seismic Design Code for Water Facilities. 88 5th AWWARF/JWWA Water System Seismic Conference SESSION 2 Seismic Measures for Pipelines Mr. Hiroaki Miyazaki, Osaka Municipal Waterworks Bureau, Osaka, JAPAN – “Seismic Damage Estimation of Distribution Pipes” Mr. David Tsztoo, East Bay Municipal Utility District, Oakland, CA, US – “Challenges of the Claremont Tunnel Seismic Upgrade Project” Mr. Yukio Mabuchi, Waterworks & Sewerage Bureau, City of Nagoya, JAPAN – “Earthquake Countermeasures in Nagoya” Mr. Ahmed Nisar, MMI Engineering, Oakland, CA, US – “Fault Crossing Design of a Critical Large Diameter Pipeline” 89 90 Seismic Damage Estimation of Distribution Pipes Hiroaki Miyazaki, Takashi Nakai, Yoshimitsu Komatsu and Kazuya Yamano ABSTRACT Osaka Municipal Waterworks Bureau made an estimate of the damage of our distribution pipes and the suspension area of water supply occurred by scenario earthquakes in Osaka city. We designed the plans of emergency water supply and emergency rehabilitation, and then we promoted earthquake preparedness projects, such as pipe replacement, based on the results of the estimation. In the seismic damage estimation of distribution pipes, we analyzed the damage record of pipes and the instrumentation record of peak ground velocity in 1995 Kobe Earthquake, and established the damage ratio equations for each pipe. However, the scenario earthquakes in Osaka city were recently reviewed which are 4 fault earthquakes such as Uemachi Faults Earthquake and Nankai Trough Earthquake. And it is found that an earthquake which scale is larger than Kobe Earthquake may occur. For this reason, we have to obtain a closer estimation of the damages occurred by a strong seismic motion that is larger than the past records. So, we started to review our method of damage estimation in 2005. In the review, we applied some achievements made available by recent research in earthquake engineering, such as the seismic motion of Kobe Earthquake that has been reproduced scientifically, and so on. And we examined damage characteristics of distribution pipe by a strong seismic motion. As a result, we improved the reproducibility in our damage estimation. In this paper, we would like to report the outline about the damage estimation of distribution pipes by a strong seismic motion both in non-liquidated ground and in liquidated ground. Hiroaki Miyazaki, Staff Officer (Earthquake Measures), Engineering Div., Osaka Municipal Waterworks Bureau, 1-14-16 Nanko-kita, Suminoe-ku, Osaka JAPAN Takashi Nakai, Staff, Planning Dept., Engineering Div., Osaka Municipal Waterworks Bureau, 1-14-16 Nanko-kita, Suminoe-ku, Osaka JAPAN Yoshimitu Komatsu, Staff, Kunijima Purification Plant, Engineering Div. Osaka Municipal Waterworks Bureau, 1-3-14 Kunijima, Higashiyodogawa-ku, Osaka JAPAN Kazuya Yamano, Manager for Crisis Management, Engineering Div. Osaka Municipal Waterworks Bureau, 1-14-16 Nanko-kita, Suminoe-ku, Osaka JAPAN 91 1. Introduction The Osaka City Waterworks Bureau has just finished drafting emergency water supply and restoration plans and been taking antiseismic measures such as to replace pipes, based on estimations of seismic damage of distribution pipes and areas affected by water supply interruptions in the event of an earthquake of parameters set by the City. The seismic damage that acted as the basis for the current emergency water supply and restoration plans and antiseismic measures was deduced from studies conducted in 1995 ~ 1996. This study analyzed the recorded peak ground velocity and seismic damage of pipes in the Kobe Earthquake (1995) and built a damage estimation model from that. Then, in 2004 ~ 2005, studies were directed at earthquakes of parameters set by the City based on newly acquired information. Results indicated that seismic motions could be greater in central Osaka than those experienced in the Kobe Earthquake. Because of this, it became necessary to estimate seismic damage under unprecedented seismic motion. Therefore, efforts were launched in 2005 to rework the seismic damage estimation model. Reworking involved analyses of seismic damage using the reproduced seismic motion of the Kobe Earthquake and interjecting the latest findings from research into earthquake-triggered disaster prevention. And, the accuracy of damage estimations was improved by adding new studies of the seismic damage models under strong seismic motion and by applying new methods of seismic damage estimation in areas where liquefaction might occur. 2. Seismic Damage Estimation Model in 1995 ~ 1996 Study The scale of seismic damage caused by an earthquake is determined by numerous factors other than the magnitude of seismic motion, to note pipe materials and coupling type, diameters at openings, year of installation, backfill conditions, ground and topological conditions, etc. Earlier seismic damage estimations by Osaka City did a regression analysis of a combination of pipes and joint types and standardized pipe diameters, from which a relational formula was built between the magnitude of seismic motion and the average failure rate (failure/km). The number of seismic failures was estimated from pipe data and set seismic motion parameters for each 250 m x 250 m cell of a city-wide projected grid. Generally, (1) peak ground acceleration (PGA), (2) peak ground velocity (PGV), (3) (measured) seismic intensity, (4) SI value, and (5) peak ground strain are considered indicators of seismic motion magnitude, but it was comparatively easy to obtain measured data and forecast data for (1) PGA and (2) PGV from past records. Toki studied the relationship between seismic failure rate and PGA and PGV, and presented data that identified a stronger correlation between PGV and seismic failure rate (damage index)1). 92 Acceleration Velocity IndexDamage (D) Velocity (cm/sec) Acceleration (g) Figure 2.1 Relationship of seismic failure rate to PGA and PGV From that research, this City dedicated to use PGV as an indicator of seismic motion magnitude. Moreover, ground conditions were reflected in the calculation process of seismic motion magnitude, however the following ground deformations were considered inapplicable to calculations. (1) Ground liquefaction and lateral fluidization (2) Slope collapses In areas where these ground deformations occurred, studies of past earthquake damage confirmed prominent seismic damage. Therefore, separate studies based on the characteristics of the target area and estimation methods were needed to determine whether these factors could be applied to seismic damage estimation. Therefore, to set correction coefficients for each factor that could affect the scope of seismic damage, Osaka City gave consideration given to opening diameters and whether liquefaction would occur or not in addition to the seismic motion magnitude for the following reasons: ・Much of Osaka City sits on an alluvial plain and there is little topology that would accompany abrupt ground changes like in the Hanshin area (Kobe City, Ashiya City, Nishinomiya City, Amagasaki City). ・Damage estimations for the city divide the city up into a grid of 250 m x 250 m cells and estimate the failure rate for each cell, therefore it would be difficult to take into consideration the detailed topologies within each cell. Here following is the seismic damage estimation formula from this study. ××= DICCDI 021 Wherein, DI: Rate of Damage (failure/km) DI0: Average Ratio of Damage (failure/km) C1: Diameter Correction Factor C2: Ground Correction Factor 93 TABLE2.1 Average Damage Ratio Equation (DI0) Pipe type Average Damage Ratio Equation DIP-S, SP-N DI0＝0.0 DIP, SP-O DI0＝0.004(PGV-20) CIP DI0＝0.010(PGV-20) CIP-L, VP DI0＝0.016*PGV DIP: Ductile Iron Pipe (mechanical joint) DIP-S: Ductile Iron Pipe (restraint joint) SP-N: Welded Steel Pipe (more than 800mm diameter or placed after 1968) SP-O: Welded Steel Pipe (less than 700mm diameter and placed before 1967) CIP: Cast Iron Pipe (mechanical joint) CIP-L: Cast Iron Pipe (lead socket joint) VP: Polyvinyl Chloride Pipe TABLE2.2 Diameter Correction Factor (C1) Diameter DIP,SP CIP VP ～75 2.1 1.7 1.1 100～150 1.0 1.2 0.8 200～250 1.0 1.1 - 300～450 1.0 0.6 - 500～ 0.2 0.2 - TABLE2.3 Ground Correction Factor (C2) DIP CIP VP landfill 2.6 2.3 1.1 Each paper must have an abstract. The abstract shall be no longer than 350 words. The abstract should present the primary objectives and scope of the study or the reasons for writing the paper. 3. Reworking of Seismic Damage Estimation Model 3.1 Background At present, Osaka City hypothesizes five types of scenario earthquakes: one ocean-trench earthquake and four inland earthquakes. The estimated scale of these earthquakes is based on studies conducted in 1995 ~ 1996. TABLE3.1 Scenario Earthquakes Classification Name Ocean-trench Earthquake Tonankai & Nankai Earthquake Uemachi Faults Earthquake Ikoma Faults Earthquake Inland Earthquake Arima-Takatsuki Faults Earthquake Median Tectonic Line Faults Earthquake Based on later studies of tectonics and active faults in Osaka Prefecture, Osaka City and Osaka Prefecture jointly formed a committee of academic experts and others in 2004, to rework the hypothesized scenario earthquakes into the following year. 94 In their work, the committee selected faults of noteworthy seismic motion potential from amongst all of the faults that could affect the Osaka Prefecture area and re-estimated the seismic motion of the five aforementioned hypothetical earthquakes. In those estimations, they created multiple destruction scenarios on combinations of asperity distributions and destruction start points. As a result, it was found that seismic motion in Osaka City could greatly exceed that of the Kobe Earthquake. 3.2 Overview of Reworking With this background, Osaka City reworked the seismic damage estimation model in 2005 ~ 2006. Based on earlier research findings, PGV was again used as the parameter for expressing seismic motion in the damage estimation model. Moreover, in order to enhance the estimation accuracy, the following new steps were taken. (1) To estimate damage in areas not exposed to liquefaction, new considerations were given to seismic damage characteristics in areas hit by strong seismic motion and simulation results were applied to the seismic damage estimation formula. (2) To estimate damage in areas exposed to liquefaction, the degree of liquefaction was assessed in grid cells using a liquefaction grading index and damage estimates were done by dividing damage into that for “seismic in non-liquefaction ground” and that for “seismic in liquefaction ground”. 4. Seismic Damage Model for Non-Liquefaction Ground 4.1 Data The Japan Water Works Association (JWWA) has studied in detail seismic damage and occurrences of liquefaction in the Kobe Earthquake. They divided damaged areas in Hanshin into 250 m x 250 m cells (approx. 4,800 cells in all) and collected information such as total pipe length and occurrences of damage by type of pipe, and occurrences of liquefaction in each cell2). Damage Ratio (failure/km) Figure 4.1 Seismic damage in Kobe Earthquake In the previous seismic damage estimation, a damage estimation model was built using only PGV logged in 29 seismic monitoring points during the Kobe Earthquake and seismic damage data in a 2 km x 2 km area around those monitoring points taken from the aforementioned cells. This study comes on the heels of the latest developments in seismological research that corroborated seismic motion of the Kobe Earthquake by waveform, and used simulation results for the Kobe Earthquake by Matsushima and Kawase3). 95 This made it possible to obtain seismic motion data for all of the aforementioned cells and greatly increased the amount of data applicable for analyses of the relationship between seismic damage and seismic motion in the Kobe Earthquake. The peak ground velocity was corrected by applying ground conditions in the concerned cells to the simulation results for engineering infrastructure of Matsushima and Kawase. Figure 4.2 Simulated seismic motion of Kobe Earthquake (Corrected for PGV) 4.2 Reworking the Seismic Damage Estimation Model (1) Sorting and Categorizing of Cell Data In reworking the seismic damage estimation model, cell data was sorted and categorized in order to eliminate factors other than seismic motion as best possible. First off, data was categorized based on occurrence of liquefaction. The JWWA arranged and recorded results of studies by Hamada et al into liquefaction occurrences in the Hanshin area during the Kobe Earthquake into 250 m x 250 m cells2). Here, cells in which sand boils occurred across most of the area and suffered numerous fissures were categorized as “liquefaction” cells, those without any occurrence of sand boils or fissures were categorized as “non-liquefaction” cells, and those with some sand boils were categorized as “semi-liquefaction” cells. Liquefaction Semi-liquefaction Non-liquefaction Figure 4.3 Occurrences of liquefaction in Kobe Earthquake In this study, cell data was categorized as “liquefaction”, “semi-liquefaction” and “non-liquefaction”, and analyses were done in “non-liquefaction” cells to identify the relationship between PGV and seismic failure rate. Furthermore, in order to eliminate the affects of damage factors other than PGV as best possible, data was sorted from topology classifications. Here, cells categorized as “valleys or former water areas” based on studies by the JWWA were excluded from the scope of analysis4). This is because 96 experience had shown that areas of abrupt topological changes such as valleys and former water areas readily suffer large ground deformations in the form of lateral flows and slope collapses. (2) Studies of Seismic Damage in Areas Hit by Strong Seismic motion In the previous study, this City used a linear regression model as the seismic damage estimation model. In other words, it is hypothesized that damage begins in a pipe located in ground where liquefaction does not occur when the PGV reaches a certain magnitude and the seismic failure rate increases as a trend alongside the increase in PGV. This hypothesis requires new studies in order to determine whether damage trends obtained from regression analysis could be applied in areas hit by stronger seismic motions that ever recorded. Studies were, therefore, launched into damage cases of the Kobe Earthquake. The JWWA has estimated the seismic intensity distribution across the Hanshin area based on the situation of collapsed structures in the Kobe Earthquake2). Seismic Intensity Over 7 7 6 5 Under 4 Figure 4.4 Seismic intensity distribution in Kobe Earthquake If this is compared against actual seismic damage (Figure. 4.1), it is seen that areas with widespread waterworks seismic damage and areas hit by strong seismic motion are not always the same. Moreover, the seismic damage around JR Takatori Station where the maximum PGV (130 cm/s) was measured was 0.5 ~ 1.0 failure/km, which is not necessarily outstanding. Next, the affect of ground binding force on buried infrastructure was investigated. Pipe damage occurs when ground strain is transmitted to pipe and pipe becomes stressed, however the relationship between pipe and ground strain when consideration is given to the pipe and ground sliding against one other is nonlinear as indicated in the Guidelines on Aseismic Design and Construction of Waterworks Infrastructure (JWWA). k k ＝ 1 2 1000 MPa ） Binding (MPa) Force 抵抗力τ（ τ k ＝ 1 δ Relative相対変位δ Displacement(m) (m) Figure 4.5 Ground strain and pipe stress model with consideration for sliding between pipe and ground 97 Moreover, experiments have confirmed existing research findings that the affect (ground binding force) of ground displacement on pipe has a maximum limit. From this information, it is thought that the ground binding force looses its affect on pipe if the ground collapses under strong seismic motion and, as a result, pipe damage does not progress above a certain point. Let us focus on the pipe for a moment. If pipe with couplings succumbs to damage because of stress formed in the pipe, the stress in the pipe is released at the fracture point. Accordingly, subsequent damage does not occur in that same spot as long as stress does not newly form in the pipe. Because of this, there is little chance in all reality that all couplings in a series of pipe would be damaged. Failure rate does not uniformly increase alongside the increase in PGV; instead, it is viewed more appropriate to set a PGV value where pipe damage converges. Based on these observations, this City adopted a nonlinear model as opposed to a linear model to estimate seismic damage including areas hit by strong seismic motion. Moreover, the PGV value at which pipe damage converge was set based on results from earthquake response simulations done by the Takada Lab at Kobe University. By quantitatively evaluating the convergence tendency for damage to increase in pipe with couplings under strong seismic motion, it was possible to build a damage model. From the results of the aforementioned investigations, the following seismic damage models were set. The seismic damage models of DIP and CIP are shown in figure 4.6 and 4.7. 2.0 1.5 1.0 Damage Ratio (failure/km) Damage 0.5 0 50 100 150 200 PGV (cm/s) Figure 4.6 seismic damage model (Non-liquefaction ground, DIP) 8.0 7.0 6.0 5.0 4.0 3.0 Damage Ratio (failure/km) 2.0 1.0 0 50 100 150 200 PGV (cm/s) Figure 4.7 seismic damage model (Non-liquefaction ground, CIP) 98 5 Seismic Damage Model for Liquefaction Ground 5.1 Seismic Damage Characteristics in Liquefaction Ground Because past records of disasters showed a tendency for seismic damage to increase in ground where liquefaction occurs in comparison to ground where it does not occur, this City estimated seismic damage in liquefaction ground by setting correction coefficients in the damage estimation model. This presupposed the primary factor for causing the seismic damage in liquefaction ground was the magnitude of seismic motion. Nevertheless, after analyzing and comparing seismic damage in cells of the Hanshin area categorized as “non-liquefaction” and “liquefaction” in the Kobe Earthquake by the JWWA (Figure. 4.2), the seismic damage in liquefaction ground did not show the same trends as in non-liquefaction ground and a significant correlation between seismic failure rate and ground velocity was not observed. Accordingly, the average was adopted on the presumption that, when the ground completely liquefied, seismic failure rate converged on a specific value without depending on PGV. 5.2 Setting of Liquefaction Area Factor In this study, seismic damage is estimated on a basis of 250 m – 250 m cells, but liquefaction across the entire area is just as imaginable as a mixture of liquefaction areas and non-liquefaction areas. Therefore, it was believed necessary towards basing seismic damage estimations on damage characteristics, to quantitatively define a degree of effect of liquefaction in the cells. In this study, the degree of ground liquefaction was evaluated as the amount of liquefied area in a given cell. A PL value was used as a ground liquefaction evaluation index and a liquefaction area factor was expressed as a function of this PL value. In building a relational formula, results from liquefaction simulations using PL values for the Kobe Earthquake5) were first compared against actual liquefaction areas (Figure. 4.3) in the Hanshin area recorded in the Kobe Earthquake. PL value Fig. 5.1 PL distribution in Hanshin area in Kobe Earthquake When both PL values and actual liquefaction areas are compared, it can be seen that a high percentage of cells are identified as liquefaction the higher the PL value is. 99 Non-liquefaction Semi-liquefaction Liquefaction PL value ~ Figure 5.2 Percentage of PL value and areas identified as liquefaction Then, in this study, attention was turned to the increase in “liquefaction” percentage seen in Figure 5.2, from which the following formula for estimating liquefaction area factor was built using PL as a parameter. 1 ⎧ P −− μ)(log 2 ⎫ A = ⋅exp L （PL>0） L σπ ⋅⋅ ⎨ σ 2 ⎬ 2 PL ⎩ 2 ⎭ = AL 0 （PL=0） Wherein, AL: Liquefaction area factor of cell µ: Population mean (= 2.88) σ : Population variance (= 0.57) PL: PL value 6 Verification of Estimation Accuracy of Seismic Damage Estimation Model From the aforementioned findings, the following formula was set as the seismic damage estimation model. {}() ×++−××= d 10 L L 00 ADIDIADICDI LL Wherein, DI: Seismic failure rate of cell (failure/km) DI0: Seismic failure rate in non-liquefaction ground (failure/km) DI0L: Average seismic failure rate in liquefaction ground (failure/km) AL: Liquefaction area factor of cell Cd: Correction coefficient based on opening diameter 100 TABLE 6.1 Seismic failure rate in non-liquefaction ground (DI0) Pipe type Seismic failure rate estimation formula DIP-S DI0＝0 DIP DI0＝0.0056（PGV－15） （PGV<150） DI0＝0.7560 （PGV>=150） CIP DI0＝0.0232（PGV－15） （PGV<120） DI0＝2.4360 （PGV>=120） VP DI0＝0.0177（PGV－15） （PGV<120） DI0＝1.8585 （PGV>=120） SP DI0＝0.0043（PGV－15） （PGV<150） DI0＝0.5805 （PGV>=150） TABLE 6.2 Seismic failure rate in liquefaction ground (DI0L) Pipe type Seismic failure rate DIP-S DI0L=0 DIP DI0L=2.56 CIP DI0L=4.00 VP DI0L=1.83 SP DI0L=0.97 TABLE 6.3 Correction coefficients based on opening diameter (Cd) Diameter DIP,SP CIP VP ～75 2.1 1.7 1.1 100～150 1.0 1.2 0.8 200～250 1.0 1.1 - 300～450 1.0 0.6 - 500～ 0.2 0.2 - The accuracy of the seismic damage estimation model developed in this study was verified from the reproducibility of the number of seismic failures that occurred in the Hanshin area in the Kobe Earthquake. Table 6.4 gives seismic failure estimates obtained with the new estimation model and actual failures. The table also lists estimates obtained with the previous estimation model developed by this City and the estimation model of the JWWA. TABLE 6.4 Simulations Actual failures New estimation model Previous estimation JWWA Liquefaction category (a) (b) b/a ( c) c/a (d) d/a Non-liquefaction 1,274 1,441 1.131 691 0.542 1,116 0.876 Semi-liquefaction 562 473 0.842 295 0.525 374 0.665 Liquefaction 336 228 0.679 105 0.313 146 0.435 All area 2,172 2,142 0.986 1,091 0.502 1,539 0.709 It can be seen from this table that the reproducibility of the new model was improved with respect to the previous model for all types of pipe. 101 Moreover, when looked at by ground definition, similar to the previous model, the new model reproduced slightly less incidents of failure in liquefaction ground than actually occurred, while in semi-liquefaction ground, it improved the reproducibility of seismic failures, which suggests that consideration for cell liquefaction area factor is an effective feature of the estimation model. From these results, the new damage estimation model is believed to be more accurate than the previous model. 7 Conclusions Worried that seismic motion could greatly exceed hypothesized levels of the existing waterworks seismic damage estimation model, this City launched a new study to develop a more accurate estimation model. Using existing research results for both areas where liquefaction occurred and did not occur and new methods of estimation, the new model proved to be more accurate in estimating seismic damage caused by seismic motion, including in areas hit by strong seismic motion. As a future topic of research, detailed studies into seismic damage in liquefaction ground are believed one possible way to enhance the estimation accuracy of this new model even further. The authors would like to express their sincere gratitude to Prof. Takada and Associate Prof. Kuwata of Kobe University for their generous advice and guidance in this study. References 1) K.Toki: Estimation of seismic damage of water system, Disaster Prevention Research Institute Annual vol.22 B-2, 1981. 2) Japan Water Works Association: Analysis of seismic damage of waterworks by 1995 Kobe earthquake, 1996. 3) S.Matushima, and H.Kawase: Multiple asperity source model of the hyogo-ken nanbu earthquake of 1995 and strong motion simulation in Kobe, Journal of structural and construction engineering transactions of Architectural Institute of Japan, 2000. 4) Japan Water Works Association: Seismic damage estimation of distribution pipes, 1998. 5) Geo-Database Information committee of Kansai: Shin Kansai Jiban (Ground of Kansai area especially Kobe to Hanshin), 1998. 102 Challenges of the Claremont Tunnel Seismic Upgrade Project David F. Tsztoo ABSTRACT The Claremont Tunnel is a 9-foot diameter, 18,065-foot long water tunnel located under the Oakland-Berkeley Hills and conveys up to 175 million gallons per day of treated water to over 800,000 East Bay Municipal Utility District customers in the San Francisco East Bay, California. The tunnel crosses the Hayward Fault and would be vulnerable to significant structural damage and blockage of water flow in a major earthquake. This paper describes the seismic improvements that were designed and constructed to allow the tunnel to survive the challenge of a magnitude 7.0 earthquake, and deliver without interruption an indispensable water supply for consumption and fire-fighting. The tunnel would have to do this despite anticipated earthquake offset displacements of up to 7.5 feet, and breakage and fallout of the tunnel lining at the fault. The paper will also discuss how the project addressed challenges of protecting nearby residences from construction damage and noise, unforgiving tunnel outage constraints resulting from the need to maintain water service during construction, and hazardous ground conditions in the tunnel excavation. David F. Tsztoo, Senior Civil Engineer, Engineering and Construction Department, East Bay Municipal Utility District, 375 – 11th Street, Oakland, CA 94607-4240. 1 103 INTRODUCTION The East Bay Municipal Utility District (EBMUD) serves over 1.2 million water customers located in Alameda and Contra Costa Counties, east of San Francisco Bay in California. EBMUD’s main water source comes from the pristine snow-melt waters of the Mokelumne River stored in Pardee Reservoir in the Sierra Nevada foothills. Three large diameter aqueducts convey the water over 90 miles westward from the reservoir to the EBMUD service area where the raw water is purified at water treatment plants located in the cities of Walnut Creek, Lafayette, and Orinda. The treated water from Orinda passes through the Claremont Tunnel under the Oakland-Berkeley Hills to the Claremont Center in Berkeley, where it enters the water distribution system. The Claremont Tunnel is the main water lifeline for over 800,000 customers residing in cities from Richmond to Oakland and San Leandro. See Figure 1. SOBRANTESOBRANTE WALNUT CREEKCREEK ORINDAORINDA LAFAYETTELAFAYETTE SANSAN PABLOPABLO UPPER UPPER SAN SANSAN SAN RAMON LEANDROLEANDRO RAMON S an F r an c CASTROCASTRO VALLEYVALLEY is SANSAN LEANDROLEANDRO co B ay Figure 1. EBMUD Service Area. IMPETUS FOR SEISMIC UPGRADES On October 17, 1989, the Loma Prieta earthquake struck the greater San Francisco Bay Area. The earthquake had a magnitude of 6.9 and was centered in the Santa Cruz Mountains 60 miles south of San Francisco. Although the event was relatively distant, significant damage was suffered by buildings, highway structures, and utilities as far away as San Francisco and Oakland. The widespread damage caused EBMUD to evaluate the potential risk of damage to its water system from major earthquakes along more local faults, including the Concord Fault, the Calaveras Fault, and the Hayward Fault, which is located approximately along the center of the EBMUD service area. See Figure 1. 2 104 The results of the studies indicated that approximately 63% of EBMUD customers would be at risk of having inadequate water service for consumption and fire fighting after a magnitude 7.0 earthquake along the Hayward Fault. Damage to the water system would be widespread: • 5,500 pipeline breaks, particularly near the fault • Four of six water treatment plants out of service • One out of every three water storage reservoirs out of service • Two out of three pumping plants out of service • Claremont Tunnel out of service • $1.9 billion in economic damage to East Bay businesses and residences [1] In 1994, EBMUD Board of Directors approved a $189 million, ten-year Seismic Improvement Program (SIP) to protect its water system from the damaging effects of major earthquakes. The program was forward-looking. Rather than waiting for the inevitable earthquakes to occur and then repair the damage, the SIP would upgrade the water system and mitigate the potential damage before it occurred. The SIP was completed in June 2007. The Claremont Tunnel Seismic Upgrade was the final key element of the SIP. SEISMIC CHALLENGE FOR CLAREMONT TUNNEL The Claremont Tunnel was originally constructed between 1927 and 1929. It has a 9-foot diameter horseshoe shaped cross section, and runs 18,065 feet long between the EBMUD Orinda Water Treatment Plant and the Claremont Center in Berkeley, where the tunnel connects to the west of hills water distribution system. The tunnel conveys from 110 to 175 million gallons of treated water each day to customers. The west end of the tunnel crosses the Hayward Fault, near the Claremont Center in Berkeley. The 1994 seismic evaluations estimated that in a magnitude 7.0 earthquake, up to 7.5 feet of horizontal offset and 0.5 feet of vertical offset displacement would occur within a 60-foot wide primary zone of the Hayward Fault, and sympathetic movements of up to 2.25 feet would occur within a 920-foot secondary zone straddling the primary fault. See Figure 2. The magnitude of these displacements would cause the tunnel to be severed at the fault and significant areas inside the tunnel would be clogged by collapsed lining and ground fallout. The tunnel would be out of service for up to six months for removal of debris and repairs. Built to 1920’s construction standards, the tunnel was lined with one-foot nominal thick unreinforced concrete. The lining was also not grouted to the surrounding ground with the modern-day practice of grout injection, or contact grouting, to fill voids between the lining and the surrounding earth. An inspection conducted inside the tunnel in February 2002 revealed the presence of holes and significant voids measuring several inches to several feet deep behind the liner, and lining as thin as one-half inch in some crown locations. The inspection identified numerous locations of weakened or deteriorated tunnel lining that would be at risk of spalling and fallout during major earthquake shaking, unless repaired [2]. CLAREMONT TUNNEL UPGRADE DESIGN The Claremont Tunnel Seismic Upgrade Project was developed in response to the seismic challenge. The project purpose was to maintain full service after a moderate earthquake and lifeline service after a magnitude 7.0 or major earthquake. 3 105 Upstream tie-in Lining repairs & contact grouting in existing tunnel Bypass Tunnel Thickened Liner 2 1/4 ft Enlarged Offset Vault Existing Tunnel 7 1/2 ft Offset Downstream tie-in Access Tunnel Figure 2. Claremont Tunnel Upgrade at the Hayward Fault. At the time of its conception, the project design was one of a kind innovation. Rather than building a new tunnel, as conventional engineering rationale recommended, it was decided to renovate the existing tunnel, and build a shorter bypass tunnel to replace the most vulnerable section of the tunnel at the Hayward Fault, as shown in Figure 2. The project included: • a 1,570-foot long bypass tunnel at the Hayward Fault, and • liner repair and contact grouting for the remainder of the existing tunnel. This bypass tunnel innovation was estimated to save over $50 million, or over 50%, of the cost of building a new tunnel. It could be constructed in as few as two or three years, and require only two outages of the tunnel, during the low water demand winters, to connect the new bypass to the existing tunnel, and to complete repairs and grouting inside the existing tunnel [3]. The project design criteria included the following: • Withstand primary fault zone offset of up to 7.5 feet plus 1.0 foot of creep • Withstand secondary fault zone offsets of up to 2.25 feet • Provide at least 175 million gallons per day (MGD) flow after a moderate earthquake • Provide at least 130 MGD flow after a major, magnitude 7.0 earthquake As shown in Figure 3, the bypass tunnel design featured a 17 feet wide, enlarged vault cross section which will accommodate up to 8.5 feet of fault offset displacement, without interruption of the water flow. A six-foot diameter, 85 feet long, structural carrier pipe, with a three inch thick steel wall, was positioned in the center of the vault to allow passage of at least 130 MGD of water flow through the debris that would fall into the tunnel at the primary fault offset. The walls of the bypass were also thickened to ten feet at the enlarged vault by the addition of concrete side drifts and to at least 2-1/2 feet in the secondary fault zones to avoid earth intrusion. 4 106 Before EQ 8.5 ft. Side Drift backfilled with concrete Carrier pipe inside enlarged vault maintains water flow 8.5 ft. After EQ 10 Feet Figure 3. Enlarged Bypass Tunnel Vault for Fault Offset. PROJECT CONSTRUCTION CHALLENGES Aside from the challenge of designing the tunnel to remain operational following a magnitude 7.0 earthquake, the project construction faced three main challenges: • Nearby residences – how does the project construction protect neighboring homes from damage and noise? • Unforgiving tunnel outage constraints – how does the project maintain continuous water service for customers while work occurs inside the tunnel? • Hazardous ground conditions – how does the project keep mining operations safe from known hazards of gas intrusion, highly variable geology, squeezing ground, and serpentinite? Nearby Residences As shown in Figure 4, the new bypass tunnel construction was located underneath many nearby residences. The residents did not hesitate to express their concerns about potential From Orinda WTP Existing Tunnel Repairs & Grouting East Tie-In Tunnel Road Vicente Road H a y w a r d F Bypass Tunnel Existing Claremont a u Tunnel lt L ine West Tie-In Roble Road Berkeley City of ne d o Oaklan Z City of ult El Camino Fa Real Access Tunnel Claremont Center BART Tunnel Portal Golden Gate Ave. Chabot Road Figure 4. Nearby Residences. 5 107 structural damage to their homes and properties from the possible use of explosives during project construction. The primary concerns included scenarios of homes and large trees sinking into holes caused by the explosives, and houses destroyed by landslides triggered by the vibrations of the explosions or by the mining equipment. Others were concerned that noise from the around-the-clock tunneling work may wake their sleep at night. The challenge posed by nearby residences was addressed by the following measures: • The construction contract required that tunnel excavation had to be completed by mechanical equipment to the extend possible, and allowed limited, controlled detonations only as a last resort to fracture and remove rock that was too difficult to excavate by mechanical means. Over 95% of the mining was completed by a Voest- Alpine AM75 roadheader mining machine. See Figures 5 and 6. • Extensometers or sensitive geotechnical instruments were used to measure vertical displacements or movements in the ground above the tunnel excavation and allow for preventative measures to be undertaken before surface settlements occurred. • Vibrations from the use of explosives and from mining equipment were limited to 0.5 inches per second of peak particle velocity (PPV), measured at 100 feet from the source. This is 25% of the 2.0 inches per second PPV criterion commonly used in the mining industry for avoiding any structural damage to buildings [4]. • Specialty consultants were hired to conduct pre-construction surveys to document existing cracks and the structural condition of neighboring homes, to establish a baseline for determining if any damage had occurred as a result of the construction. No claims were filed. Figure 5. Roadheader Mining Machine. Figure 6. Roadheader Excavating Tunnel. • A tall, sound wall was erected around the tunnel entry and equipment staging area to block noise away from nearby residences. See Figure 7. • Noisy equipment at the job site were wrapped in heavy insulation or retrofitted with large, noise damping mufflers. See Figure 8. • Noisy outdoor work and truck deliveries were limited between the hours of 7:00 a.m. and 7:00 p.m. to avoid the generation of noise when neighbors may be sleeping. • New noise-insulated windows were provided to the homes directly facing the tunnel construction at Claremont Center. 6 108 Figure 7. Sound Wall Around Tunnel Entry. Figure 8. Equipment Noise Insulation. • A community affairs representative was assigned to the project to assuage local community concerns about the construction. Throughout the construction and prior to each use of controlled detonation, the neighbors were kept informed about construction activities by meetings, newsletters, personal letters, and phone calls. Unforgiving Tunnel Outage Constraints As shown in Figure 9, the seasonal curves of water demand trace a very consistent pattern each year. Water use rises in the warm months between March and November, and decreases during the winter months from December to March. The Claremont Tunnel can only be taken out of service during the winter months when water demand falls below 150 MGD—the maximum sustainable water supply without the tunnel in service. Two winter outages of the tunnel were needed to complete repairs and grouting of the existing tunnel, and to connect the new bypass tunnel to the existing tunnel. While this work was being completed inside the tunnel, the 800,000 customers normally served by the tunnel still needed their water service to continue without interruption. Gross Demand - West of Hills 250 230 210 190 mid-November mid-March 150 MGD max supply with Claremont 170 Tunnel O/S 150 MGD 130 1997 1998 110 1999 2000 90 2001 2002 2003 70 2004 Outage 50 Jul- Jul- Jul- Aug- Aug- Aug- Sep- Sep- Oct- Oct- Oct- Nov- Nov- Dec- Dec- Dec- Jan- Jan- Feb- Feb- Feb- Mar- Mar- Apr- Apr- Apr- May- May- Jun- Jun- Jun- 01 13 25 06 18 30 11 23 05 17 29 10 22 04 16 28 09 21 02 14 26 09 21 02 14 26 08 20 01 13 25 Figure 9. Yearly Water Demand of West of Hills Customers. 7 109 The tunnel outage constraints challenge was addressed by careful planning, facility improvements elsewhere in the water system, and operational efforts. • A detailed tunnel outage plan was prepared to guide the EBMUD staff in preparations and the procedures for taking the Claremont Tunnel out of service. • Extensive hydraulic modeling was performed to analyze different scenarios of how water supply and operations could meet customer water demand. • Contingency plans were developed to ensure that all west-of-hills customers would have adequate water. For example, in the event of a system malfunction or other emergency, additional maintenance staff and a professional diver were placed on-call to respond to any necessary treatment plant or water facility repairs. • Preventative maintenance was completed at the Sobrante, San Pablo, and Upper San Leandro Water Treatment Plants (WTPs) to minimize the potential for WTP breakdowns or service disruptions while the Claremont Tunnel was out of service. • The filters, instrumentation, and control systems at all three WTPs were upgraded to provide additional water production capacity and assure that the plants could maintain high capacities during the entire tunnel outage of three months. See Figure 10. • At Sobrante WTP, plate settler equipment and cable controlled, solids handling vacuum system were installed to improve removal of high wintertime turbidity, or suspended solids, in the untreated water. See Figure 11. Plate Settler Equipment Solids Handling Cable-Vac System Figure 10. WTP Filter Improvements. Figure 11. Plate Settler and Solids Handling. • The Southern Loop Pipeline was completed in the southern portion of the EBMUD service area to provide an additional 30 MGD of treated water pumped from the EBMUD system east of the Oakland-Berkeley Hills. • Portable pumps were overhauled, tested and deployed in residential communities during the tunnel outage to redistribute water to ensure that all customers had adequate water. See Figure 12 • The three WTPs and Southern Loop Pipeline were operated at their capacities, and the portable pumps were deployed in the water distribution system for testing one or two months prior to the start of the tunnel outage. The testing verified that the facilities could generate at least a collective total of 150 MGD of water supply to meet west-of- hills customer demand. It also allowed operations staff to practice running the water 8 110 system with simulated outage conditions, make adjustments, and optimize system operations prior to the outage. Figure 12. Portable Pump Installation. Hazardous Ground Conditions Excavation for the new bypass tunnel had to be completed through an area known for its history of methane gas intrusion. The original construction of the Claremont Tunnel experienced several gas-fed fires, including one that burned for 30 days. The geology of the Hayward Fault includes highly fractured and variable ground called “mélange”, intermixed with hard silica- carbonate rock, soft fault gouge, and groundwater. The inconsistency of the material required constant vigilance by the miners for material fallout or collapse of the tunnel crown. The fault zone was also an area of “squeezing ground”, where the ground had the inclination to quickly close up any holes or excavation and create instability for the tunnel. Additionally, the local geology included significant areas of serpentinite, a rock formation with natural asbestos content and a health hazard [5]. This challenge was met by the combination of safety requirements and tunnel support systems included in the project design and construction documents, and the contractor’s means and methods of construction: • The contractor was required to comply with all California Occupational Health and Safety Administration, Mining Section, safety regulations and requirements regarding monitoring of explosive vapors, ventilation, and the prohibition of ignition sources in the tunnel. • Tunnel safety training was required for all contractor and EBMUD project staff. • All the equipment used inside the tunnel were required to be explosion-proof; free from electrical sparks or ignition sources. • A high volume, overhead ventilation system was used along the entire tunnel excavation to evacuate dust and any explosive vapors or gases from the tunnel heading and induce air flow into the tunnel at the tunnel entry. See Figure 13. • Heavy steel rib reinforcement on four or five-foot spacing, blocking, and shotcrete between the steel ribs were used along the tunnel excavation to protect the tunnel excavation and miners from fallouts of fractured, variable ground. See Figure 14. 9 111 • In areas of crushed and sheared material, spiling was used as pre-excavation support. This support consisted of drilling and placing steel rods in the crown area of the tunnel heading in advance of the excavation to form a reinforced canopy under which the excavation would take place. Figure 13. Overhead Ventilation at Heading. Figure 14. Heavy Steel Reinforcement. • Survey monitoring was used inside the tunnel to measure any changes in cross- sectional geometry and detect the onset of squeezing ground. • The above noted steel rib reinforcement, blocking and shotcrete methods were used to stabilize and maintain the tunnel opening from squeezing ground. • Shotcrete was also used as an immediate support to strengthen and prevent fallout of the tunnel face and sidewalls when the tunnel excavation was not advanced in any mining shift. These periods occurred during breakdowns and repairs of the mining equipment, or when work was temporarily halted for work holidays. • Whenever the excavation occurred in rock materials that contained serpentinite, workers were required to wear personal air packs and face masks to avoid inhalation of air-borne dust containing serpentinite. See Figure 15. • Water mist spray was used to dampen the serpentinite to lessen the generation of dust. • All excavated materials were temporarily quarantined in a materials classification area for sample testing and identification of hazardous material content, and determination of proper handling and disposal prior to leaving the site. See Figure 16. Figure 15. Air Packs Worn for Serpentinite. Figure 16. Materials Classification Area. 10 112 • As a final measure, the new bypass tunnel construction was finished with a thick lining of reinforced concrete and contact grouting. The lining measured as thick as ten feet along the enlarged vault section of the bypass. See Figure 17. Figure 17. Finished Bypass Tunnel Lining. Figure 18. Old Tunnel Section at Fault. EXISTING TUNNEL REPAIRS AND GROUTING The dramatic difference between the newly finished bypass tunnel and the old tunnel section that it replaced can be seen by comparing Figures 17 and 18. Figure 18 is a photo of the existing tunnel at the Hayward Fault taken during EBMUD’s February 2002 tunnel inspection. The new bypass replaced 1,500 feet of the existing tunnel at the Hayward Fault as this section of the old tunnel was not deemed economical or feasible to repair. It was also not strong enough and wide enough to absorb 7.5 feet of fault offset in a magnitude 7.0 earthquake and still continue to transmit a minimum of 130 MGD of water flow. It was better to replace this section with the new bypass tunnel. In 1967, galvanized W4x13 steel sets were placed on two or four foot spacing with steel tie- rods between the sets to reinforce a 42-foot length of the existing tunnel at the Hayward Fault, as shown in Figure 18. The trace of the Hayward Fault is highlighted by the red lines across the tunnel floor. The offset due to annual creep along the fault trace is highlighted by the sudden stagger in the red dots on the steel joints along the tunnel crown. Despite the added reinforcement, the lining at this location suffered significant cracking and spalling, and the steel sets and tie-rods experienced notable deformation just from an estimated 5.6 inches of fault creep from 1966 to 2002. However, the rest of the existing tunnel was still structurally sound, despite numerous cracks, holes and larger cavities in the lining. These defects were all repairable [2]. The existing tunnel repairs consisted of sealing cracks with grout, patching holes with concrete mortar, and placement of shotcrete supplemental lining in those sections of the tunnel requiring structural reinforcement to prevent potential fallout of the lining in a major earthquake. Loose or deteriorated concrete was removed or routed back to sound concrete and backfilled with 4,000 pounds/square inch (psi) concrete mortar. The supplemental lining shotcrete was also 4,000 psi strength, six-inch thick, and covered approximately 800 feet of the tunnel with spring- line cracks and offsets out of the wall plane, indicating that the cracks had progressed through the wall thickness. The repairs ranged from two-inch diameter holes to larger patches of lining 11 113 measuring up to ten feet long and up to three feet wide, and depths of two inches to over one foot, where the hole penetrated the wall thickness. See Figure 19. Figure 19. Concrete Lining Repairs. Figure 20. Contact Grout Injection. After patching and repairs, the lining was injected with 6,000 psi contact grout to fill voids behind the lining. The grout was placed with portable grout pumps and injection tubes inserted into two-inch holes drilled through the liner crown. Other holes drilled in the sidewalls served as relief holes for the grout and allowed for visual verification of the grout coverage behind the liner. See Figure 20. Approximately 130,000 cubic feet of grout mix was used in rehabilitating over 16,500 lineal feet of the existing tunnel [6]. CONCLUSION EBMUD dedicated the successful completion of the Claremont Tunnel Seismic Upgrade Project on May 30, 2007. This culminated a collaboration of EBMUD staff, consultants, and contractors on addressing the challenges associated with this project. The upgraded tunnel offers the assurance that a vital water supply will be available for EBMUD customers after the next major earthquake. The author would like to acknowledge and thank the EBMUD staff, Jacobs Associates Engineers/Consultants, and Atkinson Contractors, Inc. for their participation and support on this essential project. REFERENCES [1] G & E Engineering Systems, Inc., Seismic Evaluation Program Final Report, Appendix A, prepared for EBMUD, April 1, 1994. [2] Jacobs Associates, Claremont Tunnel Inspection of February 2002, Volumes 1 and 2, prepared for EBMUD, April 2002. [3] Orion Environmental Associates and Environmental Science Associates, EBMUD Claremont Corridor Seismic Improvements Project, Alternatives Analysis Report, prepared for EBMUD, June 2003. [4] Environmental Science Associates, EBMUD Claremont Corridor Seismic Improvements Project, Draft Environmental Impact Report, prepared for EBMUD, June 2003. [5] Jacobs Associates and Geomatrix Consultants, Claremont Tunnel Seismic Upgrade Project Geotechnical Baseline Report, prepared for EBMUD, January 2004. [6] Communication with Tom Shastid, EBMUD construction manager for Claremont Tunnel Seismic Upgrade, July 24, 2007. 12 114 Earthquake Countermeasures in Nagoya Yukio Mabuchi ABSTRACT Generally, waterworks measures taken against earthquakes combine two measures: one is preventive maintenance and the other is emergency response. Nagoya has been proceeding with three additional measures: construction of strong facilities that can withstand an earthquake, flexible facility operations that do not cause breaks in water service even if damaged, and establishment of a system in which smooth emergency activities can be conducted. Since Nagoya is an area requiring intensified measures against earthquake disaster, specifically regarding the Tokai earthquake assumed to have a high probability of occurring within 30 years, taking measures against earthquakes is an urgent topic. However, converting all of the enormous waterworks systems to be earthquake-proof requires a massive amount of funds and many years of labor. Therefore, Nagoya has been working toward achieving maximum effects with available funds as soon as possible by clarifying the facilities required to be earthquake-proof and upgrading them intensively. Moreover, while implementing conversion of the facilities to be earthquake-proof, Nagoya is also proceeding with the building of a system resistant to earthquakes from three viewpoints of dispersion of risk, provision of a backup function, and enhancement of a purified water stock function in terms of facility operations. In contrast, the provision of facilities such as emergency water supply facilities required for emergency activities, and equipment and material warehouses for disasters, ensures sufficient quantity and has now reached the point where measures to better quality must be developed. This paper introduces examples of efforts that promote residents’ “self help” in case of disaster. ______Yukio Mabuchi, Chief of Planning, Waterworks Planning Division, Planning Department, Technical Headquarters, Waterworks & Sewerage Bureau, City of Nagoya, 3-1-1, Sannomaru, Naka-ku, Nagoya, 460-8508, Japan 115 1. GENERAL OUTLINE OF THE NAGOYA CITY WATERWORKS The Nagoya City waterworks began supplying water in 1914 with surface water of the Kiso River as the water source. The water supply capacity in the early days of the system’s establishment was 51,200m3/day. Since then, expansion projects extending over eight phases were repeated as the population and the social and economic situation of Nagoya expanded; Nagoya’s facility scale now has a water supply capacity of 1,424,000m3/day. Nagoya takes in water from the Kiso River at two locations: the Inuyama Intake, located in Inuyama City; and the Asahi Intake situated in Ichinomiya City. Water taken in at the Inuyama Intake is conveyed to the Kasugai and Nabeyaueno Water Purification Plants, while water taken in at the Asahi Intake is transferred to the Oharu Water Purification Plant. Drinking water produced at the water purification plants is supplied to residents directly or via 11 distribution stations and pump stations. The positioning of those facilities is as shown in Figure 1. er Riv Kiso Inuyama Intake Kasugai Purification Plant Asahi Intake Plain Sedimentation Basin Shidami D.S. Nagoya Nabeya-ueno Purification Plant Idaka D.S. Oharu Purification Plant Heiwa Park D.S. Higashiyama D.S. Mizuho D.S. Nakagawanishi D.S. Narumi D.S. Kasugano D.S. Distribution Station : D.S. Booster Pumping Station Intake System Name of Water Purification Plant Water Supply Capacity （m3 /day） Kasugai Water Purification Plant 590,000 Inuyama System Nabeya-ueno Water Purification Plant 290,000 Asahi System Oharu Water Purification Plant 544,000 Total 1,424,000 Figure1. Map of Water Facilities 116 As for Nagoya’s geographic features and ground properties, the eastern part of it forms a moderate hilly terrain and has relatively stable ground, while the western part is flat land and its ground is soft. In the eastern area where the difference in altitude is large, water distribution areas are divided according to the ground height to achieve equalization of the water distribution pressure, and water is distributed from the distribution stations located on an area basis. On the other hand, the western area is provided with relatively wider water distribution areas because there is little or no difference in the altitude of the ground. When the overall Nagoya waterworks facilities are viewed in terms of measures taken against earthquakes, it can be said that the weakness of earthquake resistance is concentrated in western Nagoya, where the ground is soft. 2. ESTIMATED EARTHQUAKE AND PREDICTION OF DAMAGE Some investigation results regarding earthquake disaster prevention that have recently been released by the Central Disaster Prevention Council contain much information that influences the directions Nagoya’s measures against earthquakes take. To be specific, these results include: In 2002, the estimated epicenter of the possible Tokai earthquake was reviewed and Nagoya was specified as an “area requiring intensified measures against Tokai earthquake disaster.” In 2003, Nagoya was specified as a “region for promotion of earthquake disaster prevention measures” with regard to the Tounankai and Nankai earthquakes. In 2006, the seismic intensity distribution assumed that if a near-field earthquake happens in an inland area was publicized, and it was announced that shaking with a seismic intensity of 7 (on the Japanese scale of intensity) caused by a magnitude 7.6 quake occurs in Nagoya. Therefore, Nagoya must tackle measures against earthquakes recognizing that they are subjects of more importance and urgency than ever before, to prepare for large-scale earthquakes of a high probability of occurrence. TABLEⅠshows Nagoya’s estimated earthquakes and the transition of their estimated seismic intensities. As seen from the table, the seismic intensity scales of the estimated earthquakes and the maximum ground acceleration have been gradually modified to higher values by learning from past earthquake damage. TABLEⅡ is a summary of damage assumption in Nagoya based on the estimated earthquakes. 117 TABLEⅠ TRANSITION OF ESTIMATED EARTHQUAKE Transition of Estimated Earthquake Strength Earthquake History 1891 Nohbi Earthquake 1914 Kanto large Earthquake 1944 Tounankai Earthquake 1946 Nankai Earthquake 1948 Hukui Earthquake 1979 Underground Structure Ground Structure 1964 Niigata Earthquake Design seismic intensity = “0.2G” or more Corresponds to Nohbi Earthquake ( M:8.4 ) 1978 Miyagi Prefecture ( Consider Region, Ground and ( Using Static analysis and Dynamic analysis ) offing Earthquake Structural characteristic ) 1981 Nohbi Earthquake Tokai Earthquake Seismic Intensity 6 5 Max. G (gal) 400 250 1984 Nohbi Earthquake Tokai Earthquake Tounankai Earthquake Seismic Intensity 5 － 7 about 5 5 － 6 Max. G (gal) 440 260 370 1995 Kobe Earthquake 1996 Nohbi Earthquake Tokai Earthquake Tounankai Earthquake Seismic Intensity 5 or more － 7 4 － 5 or more 5 or less － 6 or less Max. G (gal) 880 220 350 “Epicenter“Epicenter regionregion ofof TokaiTokai 2002 SpecifiedSpecified “Area“Area requiringrequiring intensifiedintensified measuresmeasures againstagainst TokaiTokai EarthquakeEarthquake disasterdisaster ”” Earthquake” was reviewed SpecifiedSpecified “Region“Region forfor promotionpromotion ofof earthquakeearthquake disasterdisaster preventionprevention measures”measures” with with regardregard toto thethe TounankaiTounankai && NankaiNankai EarthquakeEarthquake ① ② Nohbi Tokai Tounankai ①＋② 2003 Earthquake Earthquake Earthquake 2004 Niigata-Tyuetu 5 or more － 4 － 5 or less － 5 or less － Seismic Intensity Earthquake 7 6 or less 6 or more 6 or more Max. G (gal) 880 329 542 542 2007 Noto Earthquake TABLEⅡ DAMAGE ASSUMPTION IN NAGOYA 1 2 Nohbi Tokai Tounankai 1 & 2 Earthquake Earthquake Earthquake Complete Destruction 23,400 2,700 16,000 21,000 Building damage Partial Destruction 99,000 15,000 50,000 59,000 Burnt Down 180 30 200 260 The fire damage Fire Occurrence 86,000 40 2,200 6,200 Death Toll Max.2,500 Max.30 Max.310 Max.420 Human damage The Persons Injured Max.44,000 Max3,800 Max.17,000 Max.21,000 Refuge Dweller 390,000 24,000 110,000 170,000 【 Damage Prediction of Distribution Pipelines 】 Immediately after Water Failure 420,000 90,000 230,000 280,000 occurrence Water Failure Rate (%) 38.7 8.0 20.6 25.0 4 days after Water Failure 190,000 3,600 120,000 150,000 occurrence Water Failure Rate (%) 19.1 3.5 11.6 14.7 Damage Rate (point/km) 0.25 0.072 0.14 0.17 3. OVERVIEW OF CONVERSION OF WATERWORKS FACILITIES TO BE EARTHQUAKE-PROOF (1) Conversion of Main Facilities to be Earthquake-proof Nagoya has pursued the conversion of main facilities to be earthquake-proof so that the estimated earthquakes can be dealt with by “strengthening of facilities,” and by “strengthening 118 of the system.” In “strengthening of facilities,” construction and improvements are implemented based on earthquake-proof design standards. In “strengthening of the system,” a backup system is planned to be built in which the water supply can be maintained even if damage occurs, such as conversion of important distribution mains to multi-pipelined and mutual connections, an increase in the service reservoir capacity, and installation of emergency stop valves. (Figure 2) Strengthening of Facilities Strengthening of System Earthquake-proof design condition Decentralization arrangement of main facilities Earthquake-proof Estimated earthquake Two or more affiliations of main pipe design standard movement Mutual connection of main facilities Past earthquake damage Review of disaster An increase in capacity of distribution reservoir prevention planning and Installation of emergency stop valve Advancement of quake-proof engineering Power failure measures Change in earthquake-proof design standard Backup system construction in emergency Review of estimated earthquake Figure2. Basic Philosophy of Making to Earthquake-proof In The Secondary Waterworks Main Facility Improvement Project now in progress, improvements are being pursued with emphasis on conversion of the main facilities located in the soft ground area of western Nagoya to be earthquake-proof by assuming a high probability of the Tokai and Tounankai earthquakes. (2) Conversion of Distribution Pipeline Network to be Earthquake-proof Nagoya began adopting earthquake-resistant pipes in 1980 on a full-scale basis. In the early days of adoption, southwestern Nagoya, where the ground is soft, was designated as an “earthquake resistant area” and earthquake-resistant pipes were installed limited to this designated area. Afterwards, the “earthquake resistant area” was gradually expanded, and in 2002 or after, earthquake-resistant pipes have been adopted in all other water supply areas. From now on, it is necessary to give priority to implementing the conversion of pipelines extending the total length to approximately 8,000 km. In The Secondary Distribution Pipeline Network Improvement Project now in progress, conversion of pipelines to be earthquake-resistant is being implemented giving priority to pipelines from the distribution mains to emergency water supply points. 119 (3) Provision of Emergency Water Supply Facilities Nagoya began providing emergency water supply facilities in 1977. Currently, these facilities are provided at 200 locations and a certain sufficiency has been met in terms of the number of facilities. Current efforts are to achieve functional improvements in which the emergency water supply facilities are upgraded to be more practicable and easy for residents to use in case of disaster. 4. CONCEPT OF EARTHQUAKE-PROOF CONVERSION PLAN As described above, taking measures against earthquakes is an urgent topic for Nagoya because of the high probability of large-scale earthquakes occurring. However, converting all the massive waterworks systems to be earthquake-proof requires an enormous amount of funds and many years of labor. Thus, the conversion plan for making the waterworks facilities earthquake-proof has been drawn up considering the following two concepts: Facilities required to be earthquake-proof have been selected and work on them is intensively being carried out. The weakness of earthquake resistance is covered by giving thought to facility operations. (1) Conversion of Facilities to be Earthquake-proof by Selection and Concentration Nagoya has been working toward achievement of maximum effects with limited funds as soon as possible by clarifying the facilities required to be earthquake-proof and intensively upgrading them. The following introduces three examples of this: (a) Intensive Earthquake-proof Conversion of a Water Transmission System with a High Risk When the amount of water to be secured in case of a large-scale earthquake is calculated through the overall systems consisting of water intake, water transmission, water purification, water supply and water distribution, the Asahi Intake system (Asahi system) especially was revealed to be largely damaged, comparing with Inuyama Intake system (Inuyama system). The Asahi system (Figure 3) consists of the Asahi Intake, Asahi transmission pipes (φ1800 mm, 3 lines), and the Oharu Water Purification Plant. This facility has been in operation for 60 years, since 1946. If the Tokai and Tounankai earthquakes strike, serious damage is predicted to occur to civil engineering structures and raw water transmission pipes in this system, and an average of only 42% on a clean water purification volume basis is estimated to be secured. Therefore, in The Secondary Waterworks Main Facility Improvement Project, upgrading has been pursued so that the amount of water secured from the Asahi system reaches a level of the maximum water supply volume achieved even in case of a large-scale earthquake. Figure 3 is a flow diagram of the secured amount of water calculated for each system in case of the predicted Tokai and Tounankai earthquakes. It is shown that conversion of the 120 facilities to be earthquake-proof with concentration on the Asahi Intake, Asahi raw water transmission pipes, and Oharu Water Purification Plant results in a situation where the total secured amount of water, including from the Inuyama system, exceeds the maximum value achieved even in case of earthquake. Influence on main facilities due to Tokai and Tounankai Earthquake Securing amount of water Asahi Intake Inuyama Intake 157,000m3 or more 565,000m3 or more 722,000m3 or more Asahi raw water transmission pipe Inuyama raw water transmission pipe 157,000m3 or more 565,000m3 or more 722,000m3 or more Plain Sedimentation Basin Oharu purification plant Nabeya-ueno Kasugai purification plant purification plant 127,000m3 or more 124,000m3 or more 395,000m3 or more 646,000m3 or more Higashiyama Shidami 77.3% 59.7% Distribution Station Distribution Station Idaka 836,161m3 1,082,516m3 Mizuho (average) (maximum) Distribution Station Distribution Station Daily water consumption Heiwa Park Nakagawanishi Kasugano Distribution Station Distribution Station Distribution Station Narumi Distribution Station Maintenance necessity Effect of earthquake measures Securing amount of water Asahi Intake Inuyama Intake 673,000m3 or more 881,000m3 or more 1,554,000m3 or more Asahi raw water transmission pipe Inuyama raw water transmission pipe 458,000m3 or more 881,000m3 or more 1,339,000m3 or more Plain Sedimentation Basin Nabeya-ueno Oharu purification plant purification plant Kasugai purification plant 341,000m3 or more 190,000m3 or more 590,000m3 or more 1,121,000m3 or more 134.1% 103.6% Higashiyama Shidami Distribution Station Distribution Station 836,161m3 1,082,516m3 Idaka Mizuho Distribution Station (average) (maximum) Distribution Station Daily water consumption Heiwa park Nakagawanishi Kasugano Distribution Station Distribution Station Distribution Station Narumi Distribution Station Maintenance completion Figure3. Evaluation of the Securing Amount of Water (before and after of measures) Improvement work of intake facilities must be carried out without stopping the raw water intake. Since the Asahi Intake comprises two independent intake systems, it is possible 121 to conduct the work by stopping the service of one system for a long period of time. Also for raw water transmission pipes, because the Asahi Intake and the water purification plant are connected using three transmission pipelines, one of the pipelines can be stopped for a long duration for the replacement work. Details of the main conversion work to be earthquake-proof are as shown in the table below. TABLEⅢ MAIN CONVERSION WORK OF ASAHI SYSTEM Name of Facilities Content of Work Intake ----- Undecided ----- Intake Underdrain Rehabilitation & Expansion joint improvement Facilities Sand Basin No.2 Ground improvement & Structural reinforcement Pumping Well No.2 ----- Undecided ----- Raw Water Transmission Pipe Replacement & Mutual connection (b) Intensive Conversion of the Oharu Water Purification Plant to be Earthquake-proof The Oharu Water Purification Plant supplies water mainly to western Nagoya, taking charge of 38% of the water supply volume of all of Nagoya City. It also has the function of partial distribution station. This plant was constructed in 1946 and its facilities have since aged, and the results of an earthquake resistance analysis revealed that many of its facilities are insufficient from the viewpoint of earthquake resistance. Moreover, the ground underneath its foundation is very soft and it is known that the ground has a high risk of liquefaction in case of an earthquake. Therefore, converting the facilities to be earthquake-proof is being intensively implemented in a five-year plan that started in 2006. Improvement work of the water purification plant must be carried out while its facilities are in operation. Because the Oharu Water Purification Plant has four independent treatment systems and has a sufficient reserve capacity of 56% average amount of purified water at maximum purification capacity, it is a water purification plant where upgrading can be done with the facilities shut down for a long period of time. Therefore, conversion work to make the facilities earthquake-proof has been progressing relatively smoothly. Details of the main earthquake-proof conversion work are as shown in the table and figure below. TABLEⅣ MAIN CONVERSION WORK OF OHARU W.P.P Name of Facilities Content of Work Raw Water Open Channel Structural reinforcement No.1 Sedimentation Basin No.2 Ground improvement & Impervious wall installation Line Filtration Pond No.2 Ground improvement & Impervious wall installation Distribution Reservoir No.1 Expansion joint improvement No.3 Raw Water Open Channel ----- Undecided ----- Line Connecting Pipe Ground improvement & Replacement Main Building ----- Undecided ----- 122 Structural reinforcement Structural reinforcement Ｎ Receiving w ell Raw water open channel Raw water open channel Inflow pipe reinforcement Sedimentation basin No.4 Sedimentation basin No.3 Structural reinforcement Sedimentation basin No.1 Sedimentation basin No.2 Inflow pipe reinforcement Liquefaction m eas ures Outflow pipe reinforcement Distribution reservoir No.3 Distribution reservoir No.2 Structural reinforcement Filtration pond No.2 Filtration pond No.3 Structural reinforcement Distribution reservoir No.1 Pumping station Main building Outflow pipe reinforcement Water supply capacity ：127,000 m3/day Water supply capacity ：214,000 m3/day Figure4. Oharu Water Purification Plant Distribution Station Distribution Main Earthquake-resistant Emergency Water Supply Piping Lines Securing for Refuge Lines e ip p n o ti Elementary u Emergency Water ib School tr Supply Station is D Figure5. Emergency Water Supply Route (c) Priority Conversion of the Emergency Water Supply Route to be Earthquake-proof Nagoya has specified distribution pipes up to emergency water supply facilities as “earthquake-resistant pipelines” and has been replacing them with earthquake-resistant pipes. In The Secondary Distribution Pipeline Network Improvement Project, improvements are being pursued on a schedule to complete the conversion of distribution pipes up to the emergency water supply facilities located in 200 locations by 2010. In addition, although elementary schools are important facilities that are used as evacuation sites and as regional disaster preventive centers in case of earthquakes, the schools with emergency water supply facilities totaled only 52 out of 260 schools. Therefore, distribution pipes leading to these elementary schools have been specified as “lines of 123 emergency water supply for refuges,” and a plan has been pushed forward to convert the pipelines to earthquake-resistant piping by 2008. (2) Covering the Weakness in Terms of Earthquake Resistance by Facility Operation While proceeding with earthquake-proof facility conversion, Nagoya has also been pushing forward, in terms of facility operation, with building of a system resistant to earthquakes from three viewpoints: dispersing risk, securing a backup function, and enhancing the purified water stock function. (a) Dispersing Risk To disperse risk in the event of an earthquake, the most important facilities are multi-line systems. For raw water transportation, two systems, the Inuyama and Asahi systems, are provided and three raw-water transmission pipes are provided for each system. Moreover, for purified water transportation from the water purification plants to the distribution stations, water conveyance mains are under construction to secure multi-transmission routes. (b) Securing a Mutual Facility Backup Function To provide a backup from another water purification plant in case of functional stoppage of a water purification plant, the purification plants were connected with each other using main pipes. Further, the two purification plants are equipped with an emergency power generator to prepare for a power failure. (c) Enhancing the Water Stock Function To secure a readily available volume of water in case of disaster, the capacity of distribution reservoirs has been increased and earthquake-resistant water storage tanks and emergency water supply centers have been provided. Moreover, outflow pipes of the distribution reservoirs and water towers are equipped with emergency stop valves. The total purified water storage capacity totalizing the capacities of the distribution reservoirs, water towers, and water storage tanks is now 649,103 m3, indicating that water supply of 12 hours or more with respect to a design daily maximum water supply volume of 1,244,000 m3 is secured. 5. CREATION OF AN ENVIRONMENTAL PROMOTING RESIDENTS’ “SELF-HELP” The provision or upgrading of facilities such as emergency water supply facilities and equipment and materials warehouses for disasters has achieved sufficiency in terms of quantity and has reached a time where development of the measures toward the fulfillment of quality is required. In 2006, Nagoya established its “Disaster Prevention Ordinances.” These ordinances clarify the allocation of roles in the event of a disaster based on the concept of “self help,” “mutual cooperation,” and “public help” and state that residents and businesses must propel 124 the creation of towns resistant to disasters in cooperation with municipal authorities. To promote the residents’ “self-help” and “mutual cooperation” required in conducting emergency activities in case of disaster, the administrative organization must create an appropriate environment for this. The following describes two examples that have been implemented as environmental creation for fostering “self-help” efforts. (1) Provision of Underground Hydrants The conventional concept of emergency water supply has been that municipal personnel transport temporary hydrants to emergency water supply facilities and then assemble them to supply water. However, immediately after occurrence of an earthquake, gathering municipal personnel is delayed and it is necessary to introduce personnel to emergency recovery. Thus, the expectation of emergency water supply is placed on residents. Therefore, Nagoya has developed an underground hydrant-type emergency water supply facility (underground hydrants) equipped with emergency faucets that enable residents to operate them by themselves to secure drinking water. (Photo) These hydrants have been installed in locations near elementary schools (208 schools) that become evacuation sites in case of a disaster, and video describing how to operate them have been distributed to residents. (2) Sale of Reserve Drinking Water for Disaster Nagoya has been selling reserve drinking water for disasters called “Meisui” that can be stored for three years to promote actions in which residents buy and store water that can last for three days per person in case of a disaster. (Photo) For how to save drinking water, in the past Nagoya has encouraged residents to store tapped water in plastic containers and replace them every three days. However, this approach required time and effort and was also impractical due to inconvenience in terms of storage. Thus, water savings was not widely carried out. Moreover, going to an emergency water supply facility and bringing water back home is a significant burden for aged people or the sick or wounded. To solve these problems and improve the rate of saving drinking water by residents, Nagoya began selling “Meisui” from 2006. Underground Hydrant “Meisui” 125 6. FUTURE TOPICS (1) Viewpoint of the Facility Maintenance Plan As described above, converting all of the massive waterworks facilities to be earthquake-proof requires much time and expense; Nagoya has been proceeding with upgrading them while pursuing maximization of effects by adopting “selection” and “concentration.” However, Nagoya City waterworks is now confronted with conditions in which facilities constructed hurriedly in response to rapid increases in water demands in the postwar period all enter their renewal period. Moreover, Nagoya City waterworks is also in a condition such that no increase in water demands is expected, forcing further strict restrictions on securing funds to provide or upgrade the facilities. Under these circumstances, facility improvement plans in the future should not be drawn up from the viewpoint of only a one-to-one relationship of conversion of the facilities to be earthquake-proof for taking measures against earthquakes. Rather, they must be laid out from a more multifaceted viewpoint such as upgrading aged facilities, efficient operations of facilities, conversion of facilities to more efficient sizes, and consideration of environmental preservation. (2) Change from Securing Sufficient Quantity to Ensuring Quality Up to now, Nagoya has worked toward facility enrichment and betterment so that all residents can reach emergency water supply facilities on foot, and has completed efforts to provide such facilities in 200 locations. Currently, new efforts are being made to make these facilities easy to use by and more functional for refugees and municipal personnel. On the other hand, for stockpiling reserve purified water, a certain sufficiency has been met in terms of the overall amount of water thanks to provision and upgrading of water reservoirs, etc.; however, there is still a problem of resolving the regionally uneven distribution that exists in the amount of water stored. Future measures against earthquakes must step up from pursuing results indexes such as the secured amount of water in case of an earthquake or the rate of conversion to be earthquake-proof, toward a new stage of pursuing quality, in which the results cannot be represented in numbers. Finally, since most of the main facilities are now provided as multi-line systems, upgrading work of the Nagoya City waterworks can be achieved without significant interference in terms of water handling. It is our responsibility to pass on to future generations the waterworks developed from our predecessors’ wisdom and ideas as sustainable waterworks. 126 Fault Crossing Design of a Critical Large Diameter Pipeline. Ahmed Nisar, and Nikolay Doumbalski ABSTRACT The paper describes the analytical basis used for the design of a 66-inch diameter pipeline crossing the Calaveras Fault, a major strike-slip fault with a high probability of generating an earthquake as large as Magnitude 7.0 in the next 30 years. The basic design criterion for the pipeline is to withstand 5 to 6 feet of horizontal and one foot vertical displacement without failure. The new pipeline together with three existing pipelines (69, 96 and 91 inch diameter) is an important element of water supply system for San Francisco and surrounding communities. The overall goal for the project is to provide 120 mgd (approximately 0.5 million cubic meters/day) within 24 hours of a major earthquake. A detailed nonlinear analysis of the pipeline subjected to fault displacement is performed using the ANSYS software. The model uses nonlinear soil and material properties for the pipeline. The pipeline response was studied using both line and shell element models. The former was used to predict the global response of the pipeline, and the latter to study cross-sectional deformation, ovalization and wrinkling of the pipe cross-section. The effects of seam welds on the local wrinkling and cross-sectional ovalization were also studied. Several parametric studies were performed for the purposes of design optimization and dealing with uncertainty associated with fault location and backfill properties. Ahmed Nisar, Associate, MMI Engineering, 475 14th Street, Suite 400, Oakland, CA, 94612 Nikolay Doumbalski, Project Professional, MMI Engineering, 475 14th Street, Suite 400, Oakland, CA, 94612 1 127 INTRODUCTION The San Francisco Public Utilities Commission (SFPUC) supplies water to over 2.3 million people in four of the largest San Francisco Bay Area counties. The SFPUC system consists of three regional water supply and conveyance systems that include the Hetch Hetchy system, the Alameda system and the Peninsula system.[1] The Hetch Hetchy system is the main water supply source, providing more than 80% of the total SFPUC system supply. The system originates in central Sierra Nevada and is supplied by runoff from the upper Tuolomne River. The runoff is collected in three major reservoirs: the Hetch Hetchy, Lake Lloyd and Lake Eleanor. Water from the reservoirs is diverted through a series of tunnels and aqueducts into the San Joaquin pipelines that transport water across the Central Valley to the Bay Area. Three large diameter pipelines called the Alameda Siphons transfer water through the Sunol Valley, across the Calaveras Fault. This paper describes the analytical basis for the design of a new (66-inch diameter) fourth pipe line, the Alameda Siphon No. 4 (AS4). The SFPUC water system is shown in Figure 1. Hayward Fault Calaveras Fault Alameda Siphons San Andreas Fault Source: http://sfwater.org Figure 1. Hetch-Hetchy Regional Water System Map As shown in Figure 1, the Alameda siphons cross the Calaveras Fault, a major northwest-southeast trending strike slip fault. The Calaveras Fault is one of the most active faults in the Bay Area. The Working Group on California Earthquake Probabilities has estimated an 11% probability of a Magnitude 6.7 or greater on the Calaveras fault in the next 30 years.[2] Geologic and seismicity studies show the fault to be segmented with the northern segment significantly distinct from its segment to the south. The fault segment of interest to the siphons has a geologic slip rate of 6+/-2 mm/yr and is considered capable of producing an earthquake as large as magnitude 7.0. Surface fault rupture displacement associated with such an event is estimated to be on the order of five to six feet lateral and up to one foot vertical. [2, 3] The three existing siphons consisting of the Alameda Siphon No. 1 (AS1), a 69-inch reinforced concrete cylinder pipe built in 1933, the Alameda Siphon No. 2 (AS2), a 91-inch welded steel pipe built in 1952 and the Alameda Siphon No. 3 (AS3), a prestressed concrete cylinder pipe built in 1966 were not explicitly designed to withstand large fault displacements, and are likely to fail during a 2 128 surface rupturing event on the Calaveras Fault. Out of these, the AS2 with double lap welded joints has some potential for withstanding relatively large ground displacements. However, due to stress concentrations caused by the presence of structural features such as valve and chemical injection vaults within the fault deformation zone, it is unlikely that AS2 is capable of withstanding the expected fault displacement. As shown in Figure 1, the Alameda siphons transfer water from the east to water customers to the west. Because of their importance to water delivery, the SFPUC has assigned a high performance standard for the design of the new AS4. Accordingly, the performance criteria is to provide 120 million gallons per day (MGD) within 24 hours of a major earthquake. At the time of the writing of this paper, the project is still in progress with both the design work and the fault investigation and interpretive work ongoing. This paper describes the analytical approach being used for the design of the new siphon, and the results from the first cycle of design and analysis process. The paper also highlights some of the challenges in proceeding with analysis and design tasks, to meet the project schedule, in parallel with ongoing field geologic and geotechnical investigations and interpretive work. PIPELINE ALIGNMENT AND PROFILE The proposed new and existing siphons run in an east-west direction across the Sunol Valley between the Coast Range Tunnel (CRT) to the east and the Irvington Tunnel to the west. The siphons’ connection to each tunnel is though a 10.5 feet diameter and 53 feet long manifold pipe. The new siphon will connect to the CRT manifold through a modification of AS2 connection. From the manifold, the new pipeline is routed under the Calaveras Road and across the Calaveras Fault. Further downstream, the pipeline crosses beneath the Alameda Creek and then connects to a mixing chamber that blends water from all four siphons. The mixing chamber is then connected to the Irvington Tunnel. A preliminary alignment and conceptual design for the new pipeline were developed as part of planning studies.[3] The alignment consisted of crossing the fault at a 26 degree angle to minimize compression and bending response of the pipeline subjected to fault rupture displacement. The proposed alignment of the conceptual design was modified somewhat to accommodate several existing physical features in the proximity of the fault zone. The revised alignment is shown in Figure 2. An important consideration for fault crossing design is to maximize the tensile response of the pipeline and minimize the presence of structural features that could result in localized compression and stress concentrations. Therefore, within the zone of large pipe strains resulting from fault rupture displacement, vertical and horizontal alignment changes and presence of hard points such as valves should be avoided. In addition, use of loose backfill that allows the pipeline to deform, laterally and axially, without significant soil resistance substantially improves pipeline response. A major challenge for this project was to not only to include all the special design features required for a fault crossing design but also that the design met the constraints imposed by the presence of existing features and constructability issues. Some of the most significant constraints included: (a) the relatively close proximity of the fault zone to the CRT manifold; (b) steep vertical grade change to connect to the CRT manifold; (c) close proximity of the Calaveras Road to the fault zone, and hence a requirement for dense subgrade to carry heavy traffic loads; (d) provision of an emergency shutoff valve between the manifold and the fault zone, thereby introducing a hard point; and (e) minimizing loads to the existing manifold, which is not designed to carry large forces. Each one of these 3 129 constraints imposes significant restrictions on the pipeline design, which must be accommodated for the design to be viable. PLAN 100 feet wide Calaveras Fault Zone Calaveras Road Smoothed Bend (5 Degree Miters) Existing Pump Station Connection to Concrete Encased Alameda Creek CRT Manifold Mixing Chamber Crossing (108 inch diameter) PROFILE Figure 2. Alameda Siphon No. 4 – Alignment and Profile APPROACH The approach used for the project consisted of design through detailed analysis. This approach constitutes utilizing successively refined analytical models as the design evolves. The process involves systematically developing insights into the structural response of the pipeline and using these insights to guide subsequent design decisions, which are then included in a more refined analytical model for the next design cycle until the design and analysis process converges. The scope of the first cycle of analysis, presented in this paper, was to assess any fatal flaws in the design concept while recognizing that the field investigation work was not completed. In an effort to maintain the project schedule, the analysis work included parametric studies with reasonably conservative assumptions so that other design tasks could proceed, with the intention of further refining the analytical model as additional information becomes available. To study the pipeline response subjected to fault rupture displacements, a nonlinear finite element analysis was performed using the ANSYS[5] general purpose finite element program. The model included large displacement, nonlinear material properties for the pipe steel and nonlinear soil springs. Description of Finite Element Model Two different finite element models were developed. The first used line elements to assess the global response of the pipeline, and the second used shell elements to model the portion of the pipeline most impacted by the fault rupture to study the local cross-sectional wrinkling and ovalization. The line element model was developed using PIPE20, a special pipe element in ANSYS capable of large displacement and plastic deformation. The element has eight integration points along its circumference and is a better predictor of pipeline response than a simple beam element. A total of 4 130 394 pipe elements ranging in size from 6 to 12 feet were used, with the smaller element lengths used in the vicinity of the fault zone. The geometry of the line element model is shown in Figure 2. The shell element model was developed using nonlinear shell elements to capture the localized behavior of the pipeline within the fault zone. Initially 24 elements across the cross section were used, which was later refined to 48 elements across the cross section. The refinement was based on results of the 24 element model that did not seem to capture the cross sectional deformation adequately. The element size for the 48 element model was approximately 4.3 inch squares. The linear extent of the shell element models was extended to the point where the results of the line element model showed negligible pipe strain. All nodes at the endpoints of the shell element model were assumed to move with the soil (i.e. no relative displacement between pipe and soil). A total of 28, 416 elements constituted the 48 element model. In general, the runtime associated with the model was reasonable, however, for some analysis cases with large plastic deformations and cross section ovalization the run time on a 64bit “AMD Opteron Dual Core” processor excided 48 hours. Soil Modeling The resistance to pipe movement provided by the backfill and insitu soil was included in the finite element model through the use of bi-linear soil springs specified at each node of the model. For the initial set of analyses, the springs were computed using established procedures.[6, 7] Four spring values for each node were specified that included an axial spring to model resistance to deformation along the pipe-soil interface, a lateral springs to capture the lateral resistance of backfill and a set of up and down springs to model the, upward and downward resistance of soil to pipe displacement. The spring formulation used for the computation of spring values are a function of outside diameter and burial depth of the pipeline, in addition to various soil properties. Because burial depth and the outside pipeline diameter (due to concrete encasement under Calaveras Road and Alameda Creek) is not constant along the pipeline unique springs values were computed for each node of both the line and shell element models. For the shell element model a total of 56,736 nonlinear spring elements were used. Parametric studies using 50% and 200% of the computed spring values were performed to capture the uncertainty in computation of soil springs, the possible variation in soil properties because of ongoing geotechnical investigations and interpretations, and possible modification to pipeline profile. Surface Fault Displacement Due to ongoing geologic investigations at the time of the first cycle of design and analysis a 100 foot wide zone, as shown in Figure 2, was assumed. This zone had been identified as the possible location of the main trace of the Calaveras Fault from the initial set of geologic investigations. To study the impact of the uncertainty in the exact fault location within the fault zone, analyses were conducted assuming the fault to be located along the eastern and the western margins of this 100 foot wide zone. Locating the fault at the eastern margin of the fault zone represented a conservative interpretation with regards to pipeline response beneath the Calaveras Road and the connection to the CRT manifold, while its location along the western margin of the fault zone represented a conservative interpretation with regards to possible stress concentration at the change in alignment west of the fault zone (Figure 2). For each assumed fault location, the total rupture displacement was applied over one element length by incrementally displacing all soil anchor point nodes to the east of the assumed fault location. 5 131 ANALYSIS RESULTS For the first design cycle, analyses were conducted assuming 0.5, 0.75 and 1.0 inch pipe thickness in the area of influence of fault rupture, which was taken as 100 feet on either side of the 100 foot wide fault zone (total length of 300 feet). The pipeline alignment was constrained based on conceptual design and constructability requirements. The remainder of the pipe was assumed to have 0.5-inch wall thickness. The backfill properties were assumed to represent native soil conditions, i.e. no special conditions such as special trench with loose backfill. Use of a special trapezoidal trench with loose backfill within the fault zone reduces the axial and lateral restraint to pipe and allows it to deform to accommodate large fault displacement[6]. To study the effect of variability in backfill properties and spring computations, additional analyses using 50% and 200% of soil springs representing native backfill conditions were performed for the pipe with 0.75-inch wall thickness. An additional analysis using softer springs within the 300-foot long fault rupture influence zone to model the effect of loose backfill was also considered. The results from the various line element models show that by increasing the pipe thickness from 0.5 to 0.75 inches the maximum tensile strain decreases by about 29% and by an additional 17% if the pipe thickness is increased to 1.0 inches (the maximum tensile strain for a 0.5 inch pipe is over 5% while that for a 1.0 inch pipe it is close to 3%). In general, for maintaining pressure integrity allowable tensile strains below 4% to 5% and allowable compressive strains below 2% to 3% for similar pipeline size and diameter to thickness ratios as AS4 are recommended[7]. The results with 50% reduction in soil spring stiffness show a 41% reduction in maximum tensile strain. For the case in which the spring stiffness was increased by a factor of two, non-convergence occurred at five feet of fault displacement compared to 6.25 feet for the other cases. The maximum tensile strain at five feet of displacement was close to 6%. Sample results for the 0.5-inch thick pipe and an assumed 6.25 feet of fault displacement applied at the eastern edge of the fault zone are shown in Figure 3. Based on the results from the line element model, it appears that the 0.75 and 1.0 inch thick pipes perform substantially better than the 0.5 inch thick pipe. However, results from the shell element model show significantly higher localized tensile strains for the 0.75 inch thick pipe. Compared to the line element model, the maximum tensile strain for the shell element model is close to two times that of the line element model. The results also show close to 35% reduction in cross sectional area with maximum compressive strains greater that 10%. The shell element model shows that by increasing the pipe thickness from 0.75 to 1.0 inch the maximum tensile strains are further reduced by approximately 45% and the maximum compressive strain by a factor of over three with a corresponding reduction in cross sectional area of just 5%. The main reason for this difference in the line element and shell element model results is the ability to more accurately capture large strains along the cross-section in the shell element model, which cannot be captured in the line element model. Parametric studies to evaluate the impact of steel grade and alignment change did not show a very significant improvement in the pipeline performance. However, the impact of loose backfill on pipe performance was substantial. For the 0.75 inch thick pipe the maximum tensile and compressive strains were reduced in half. The reduction in cross sectional area for this case was 25% compared to 35% that did not consider special trench. Similarly for the 1.0 inch thick pipe, the reduction in maximum tensile and compressive strains by using the special trench were 17% and 31%, respectively and the reduction in cross sectional area of only 2% with no wrinkling. Sample results 6 132 from the shell element model for the 0.75-inch thick pipe with standard backfill properties representing native soil conditions are shown in Figure 4. An important consideration for the pipeline subjected to large displacements is to minimize zones of potential stress concentrations. Ideally for such applications, a seamless pipe would be preferred. However, for a 66-inch outside diameter pipeline the only viable options are either longitudinal or spiral welded pipe. A preliminary set of analysis using shell elements was conducted for the 1.0 inch thick pipe including detailed modeling of the longitudinal seam welds. The results from the analysis show slightly lower cross-sectional deformation (1% reduction in cross sectional area compared to 2%) and a significant reduction in compressive strains (approximately 27%). This is possibly due to the stiffening effect of the welds that reduces the cross sectional deformation and compressive strains. Maximum Compressive Strain = 0.051 Maximum Compressive Strain = -0.015 Legend: Tensile Strain Legend: Compressive Strain Applied Fault Displacement = 6.25 feet Figure 3. Sample Results Line Element Model 7 133 Maximum Tensile Strain (7.4%) Maximum Tensile Strain (3.3%) at 5 feet of Fault Displacement at 6 feet of Fault Displacement (0.75 inch pipe) (1.00 inch pipe) Max. Compressive Strain (8.2%) Maximum Compressive Strain (2.2%) at 10 feet of Fault Displacement at 6 feet of Fault Displacement (1.00 inch pipe) (1.00 inch pipe) Figure 4. Sample Results Shell Element Model CONCLUSIONS This paper presents the analytical basis for the design of a critical large diameter water pipeline crossing a major active fault. Due to the critical nature of the pipeline, the performance criteria calls for continued operation and maintaining pressure integrity and providing 120 mgd within 24 hours of a major a surface rupturing earthquake on the Calaveras Fault. Nonlinear finite element analyses are conducted using the ANSYS software to support the pipeline design. The analytical aspect of the work has been integrated in the early design process to provide greater insight and minimize design iterations. The results of the analysis show that especially for a large diameter pipe with a large D/t ratio a detailed shell element model provides essential information regarding cross-sectional deformation such as ovalization and local wrinkling that the typically used line element model does not. ACKNOWLEDGMENTS Work presented in this paper is part of the SFPUC’s Alameda siphons project. Ms. Annie Li is the SFPUC Project Manager for this project and Mr. Sam Young, the Project Engineer. Other key individuals from the SFPUC include Mr. Ramon Garcia, Mr. David Hung, Mr. Joseph Buitrago, Mr. Joseph Haas and Mr. Steven Shaw. 8 134 MMI Engineering is a part of the Black & Veatch/AGS Joint Venture (BV/AGS JV) team responsible for the project. The work presented in this paper is part of a collaborative effort between several key individuals on the team. We acknowledge the support of Mr. Arne Nervik and Dr. Chris Mueller of Black & Veatch, respectively Project Engineer and Project Manager for the BV/AGS JV supported by Mr. Paul Kneitz, Alex Christenson, and Jimmy Leong of Black & Veatch, Mr. Bahram Khamenehpour of AGS, Inc. supported by Mr. Mikko Valkonen and Doug Herold of AGS, Mr. Keith Kelson and Mr. Sean Sundermann of William Lettis & Associates, Mr. Andy Herlache and Michael Boone of Fugro and Mr. Tony Dover of Geosyntec Consultants technical reviewer for the project. REFERENCES [1] Bay Area Water Users Association, “Water Supply Master Plan” April 2000 [2] Working Group on California Earthquake Probabilities, “Earthquake Probabilities in the San Francisco Bay Region: 2002 – 2031”, USGS Open File Report 03-214, 2003 [3] Kelson, K.I., 2001, “Geologic characterization of the Calaveras fault as a potential seismic source, San Francisco Bare Area, California”, in Ferriz, H. and Anderson, R., eds., Engineering Geology Practice in Northern California, Association of Engineering Geologists: California Division of Mines and Geology, Special Publication 210, p. 15-28 [4] Water Infrastructure Partners (WIP), “New Irvington Tunnel Conceptual Engineering Report”, for San Francisco Public Utilities Commission, Project No. CUW 35901, September 2005 [5] ANSYS Release 10.0, ANSYS Inc., Southpointe, 275 Technology Drive, Canonsburg, PA 15317, www.ansys.com [6] Pipeline Research Council International, Inc. (PRCI), “Guidelines for the Seismic Design and Assessment of Natural Gas and Liquid Hydrocarbon Pipelines, Catalog No. L51927, October 1, 2004 [7] American Lifelines Alliance (ALA), “Seismic Guidelines for Water Pipelines”, www.americanlifelinesalliance.org, March 2005 9 135 136 5th AWWARF/JWWA Water System Seismic Conference SESSION 3 Outreach, Education and Communications for Earthquake Risks Mr. Kazuhiko Mizuguchi, Kobe Municipal Waterworks, Kobe, JAPAN – “Seismic Practices and Strategies of Public Relations in Kobe City” Prof. Adam Rose, University of Southern California, US – “Regional Economic Analysis of Earthquake Losses, Mitigation and Resilience” Dr. Nagahisa Hirayama, Disaster Reduction and Human Renovation Institute, Kobe, JAPAN – “Participatory Planning in Development of Comprehensive Crisis Management Plan for Water Supply Authorities” Mr. Luke Cheng, San Francisco Public Utilities Commission, San Francisco, CA, US – “Seismic Aspects of the SFPUC Water System Improvement Program” Mr. Shinji Nakayasu, Hanshin Water Supply Authority, Hyogo, JAPAN – “Information Provision to Residents on Construction of Regulating Reservoir at Landslide Site Caused by an Earthquake” 137 138 Seismic practices and Strategies of Public Relations in Kobe City Kazuhiko MIZUGUCHI1 ABSTRACT Kobe Water has been promoting various seismic practices on some lessons learned from the Hanshin-Awaji disaster. There have been several great earthquakes since 1995. As we obtained some new knowledge from those disasters, we are reconsidering the policy of seismic practices. Since, it has been passed 12 and a half years, about quarter of the residents in Kobe has not experienced the Great Earthquake. This means the lack of recognition for the terrible disaster. Some great earthquakes are supposed to occur in the near future around KANSAI region. It is very important to mitigate a disaster , we should make public seismic practices and correspondence after the earthquake for the citizen for this reason. We usually take seismic practices into consideration when the aged facilities are replaced and reconstructed. Especially, we have promoted to install the distribution pipes connecting to the hospitals and disaster prevention centers by priority. We have a research program for evaluation of existing distribution pipes. By this program, we decide priority for replacement of pipes with a limited budget. And, a similar program on transmission and conveyance facilities is under development. We are constructing Emergency Water Supply System, Large Capacity Transmission Main, and so on. And we make public the progress of those seismic practices on our website and through emergency exercises to the citizen. Despite this, the citizens do not know the actual situation. And they are eager for seismic upgrading. We will install a drinking fountain at some elementary schools that will become the disaster prevention centers. Those facilities have function of emergency water supply at the time of disasters. We call this “ITSUDEMO-JAGUCHI”, which means the water supply can be served anytime even in an early stage of disaster. We want to use this as a communication tool to the consumers. We know it is very important to make public our practices to mitigate the effect of disaster as well as the seismic practices. In this paper, the author describes the details of recent seismic practices and the strategies of public relations. Kazuhiko MIZUGUCHI , Manager, Planning and Design Division, Kobe City Waterworks Bureau 6-5-1, Kanou-cho, Tyuou-ku, Kobe, 650-8570, Japan 139 １． Introduction Kobe City is the beautiful port city located on the north side of Osaka bay, and it is one of the famous tourist spots in Japan. The population is about 1.53 million. But, a lot of the infrastructure suffered terrible damage by the Great Earthquake that deprived 6,434 lives in 1995. Kobe Water has been proceeding with seismic practices of the water supply system on “Basic Plan for Earthquake- resistant Water Supply Facilities”. That is based on some related opinions and our experiences during the disaster. There were so many disasters by great earthquakes all over the world recently. Because we could get a lot of new knowledge from them, we should verify the present plan of seismic practices. The population of Kobe City was decreased about 100,000 right after the disaster. It took about 9 years to exceed the population before the earthquake. And that shows a tendency to increase even now. Since it has been passed 12 and a half years, about quarter of the residents in Kobe did not experience the Great Earthquake. This means the lack of recognition for the terrible disaster. Our staff members who were active in the forefront at the time of the disaster did already retire in large quantities. For those reasons, it is concerned to fade away the lessons against the disaster. Some ocean type great earthquakes are supposed to occur in the near future around KANSAI region. There is 50 or 60% probability of occurrence within 30 years. Therefore we should promote the whole seismic practices of the water supply system. It is very important to share accurate information about the seismic practices, and the correspondence after an earthquake between water supplier and the consumers. And, we think the training in cooperation with the citizen is very useful to mitigate the effect of disaster. In this paper, the author describes the details of recent seismic practices in Kobe City, and about “ITUDEMO-JYAGUTI” that is one of the strategies of public relations. ２． The Outline of Kobe Water Kobe City has no large rivers and lakes that are reserved as water sources. Therefore, Kobe Water is obligated to depend on about 75% of its entire water demand from the Hanshin Water Supply Authority; that draws water from Lake BIWA and the YODO River. Since our main water source is depends on the east side of the city area, the length of transmission and distribution pipes is about 5,000km. And there are 3 reservoirs and 6 water purification plants. And it is a characteristic that the number of the distribution reservoirs is 251 in 123 places because of the mountainous district. We adopt the gravitational water supply system with those facilities. ３． The Policy of Seismic practices on the Water Supply Facilities Kobe water started to promote seismic practices such as seismic design against the previous earthquakes, adoption of seismic joint, construction of Emergency Storage System, before the disaster. Moreover, we divided a pipe network in some blocks, and connected neighboring ones, so that each of them had a mutual backup function for disasters and accidents. But, terrible damage especially appeared on the pipeline in coastal area and the man-made island. 140 But, the main facilities such as distribution reservoirs and purification plants suffered hardly damage by the Great Earthquake, because those were built on the firm ground of the foot of a mountain area. The acceleration of the earthquake wave in mountain area was relatively small, and those facilities were designed as the watertight structures with the decreased allowable stress. We have been promoting seismic practices on the Basic Plan. We have been carrying out the effective investment in seismic practices with a limited budget, because a large amount of facilities will have to be renewed in the near future. And, we installed the monitoring and controlling system for central control, because there were a lot of scattered water supply facilities in the city. A back-up system was built for the seismic upgrading of those systems after the disaster. For example, we promoted a duplication of communication network and incoming circuit, and installed private electric generators. The outline of main seismic practices is as follows. 1) Distribution Pipes As the distribution pipes suffered by 1,757 places, the seismic practices of distribution pipes were carried out mainly and preferentially after the disaster. That length of replacement is about 118km. Especially the aged pipes of the 500m-grid trunk line have been replaced for the seismic practices. Since there was no water at the time of the disaster, there were so many troubles in the city; an operation at the hospitals and refuse burning at the incineration plants. For that, the distribution pipes which connect to those facilities and the emergency stations have been making seismic upgrading. We have been making replacement of the distribution pipes, in accordance with the redevelopment projects and the road repair works after the disaster. The rate of replacement to the whole length (about 4,600km) is about 28% as that result. As for the 500m-grid trunk line, that is about 42%. The rate is about 33% in the downtown area where the damage was terrible. On the other hand, the rate is only about 25 % in the northern and western area; those were developed as new towns and industrial parks after the 1960's. Therefore, we must replace them for seismic practices, when large quantities of water supply facilities are renewed. We have "the mapping system" which records type of pipe material and joint, diameter, construction age, position of underground installation. This system has been applied since 1991. Recently, we developed “the Pipe Network Restructuring Program” with the use of this system. The data of accident records, ground condition such as liquefaction and corrosion soil, and substitutive function are installed in this program. Since this program can evaluate a distribution pipe network totally, we can decide the priority of renewal and seismic upgrading among a lot of distribution pipes. TABLE I. THE CONDITIONS OF SEISMIC PRACTICES ON DISTRIBUTION PIPES 〔Unit : km〕 Route Seismic Pipe Total extension (A/B) extension (B) 500m-grid line 270 650 42% 200m-grid line 320 1,060 30% Others 690 2,890 24% Total 1,280 4,600 28% 141 Mapping System Database Renewal of Investigation, Measurement Data Pipeline ・Remaining Chlorine Concentration ・Corrosion Conditions of Pipe Body Program ・Water pressure etc. Diagnosis of Pipe Network Function Evaluation Planning Priority of renewal Hydraulic Analysis Demander service Cost-effectiveness Planning of Renewal, Wate r Quality Analysis Seismic Practices Aging Analysis Seismic Reliability Analysis Planning and Countermeasure Total Importance of the Emergency Fig.-1.The Outline of the Pipe Network Restructuring Program 2) Reservoirs The NUNOBIKI reservoir served from 3,640 1900 was carried out emergency restoration with mortar grout, because water leakage had Full Water Level increased after the earthquake. The expert 300 committee made the conclusion on the risk of R= turnover after examining the resistance to earthquake. Therefore, after the construction of (Unit : m) a temporary road and making a reservoir empty, we reinforced with concrete "fillet" that was increased on the dam bank inside of the 33,330 body. And an existent bank body was upgraded structurally. The work period was about 3 and a half years, and the construction Filet was completed in March 2005. There was no problem by the diagnosis as 通廊 for two other reservoirs, but we are verifying the safety on the large-scale earthquake in this 23,693 year again. 1,000 4,547 Fig.-2. Seismic practices of the NUNOBIKI Reservoir 142 3) Distribution Reservoirs As the seismic practices of the distribution pipes; suffering of terrible damage, did progress to a certain extent, we decided to promote the seismic practices of the main facilities that were hardly suffered with the disaster. There are 123 distribution reservoir sites in Kobe City. Though each construction age of all reservoirs is different, but we can find out some similarities among a lot of structures. We do not think it is not necessary to analyze and diagnose for all reservoirs, so we sorted them into several groups. We picked up the typical one in term of repair time, ground condition, structure type before we are diagnosed them. The following points were found out by examining the result of the analysis about the RC distribution reservoir with four walls. (1) The earthquake resistance ability with two-dimensional analysis is underestimated, as a result of the three-dimensional analysis. Because the effect of four walls is not being taken into consideration. (2) The decay constant of the structure against the large-scale earthquake is provided 5% in the present seismic design in Japan, but we think it should be about 15% because of the width of deck slab. As a result, it is considered that a resistance to earthquake is underestimated. As for the PC distribution reservoirs, we are diagnosing them at present. The deterioration diagnosis of each distribution reservoir is being carried out about the neutralization, the deterioration conditions of coating layer, the existence of crack, and so on, to figure out the situation on the structures for the analysis. Moreover, we must consider "the level of accumulated damage" to verify the analytic validity of the facilities that have suffered an earthquake disaster. For example, as for the distribution pipes that suffered liquefaction, their joints may separate at the time of a large earthquake, in case that displacement of the joints has been reached almost maximum value to an acceptable one. We must confirm the accurate displacement of the pipeline after disasters. As for the structures that were suffered once and needed no repair work, it is not always true to get same damage, even if an exactly same earthquake would occur. We must figure out the structural deformation and crack information precisely after an earthquake. When a resistance to earthquake is evaluated, the level of accumulated damage must be taken into consideration. We need to try to evaluate the degree of influence on the repair history. 4) Conveyance and Transmission Tunnels The existing transmission tunnels located in the east and west of the city area may be taken some suffering. As there were no substitutive facilities to renew the damaged tunnels, we had been constructing “Large Capacity Transmission Main (LATM)” from right after the disaster. We connected existing transmission tunnel and the branch line of LCTM each other this spring, based on the result of laboratory experiment. As a result, ladder-shaped transmission network was formed. We can make the existing transmission tunnel empty, and start internal investigation and renewal. 143 ③ Prefecture Ｌｅｇｅｎｄ SANDA SENGARI City Water ① ②＋④ ② ①＋⑤ Prefecture ② ②＋③ E.C.P Water ①＋② Private Water MIKI City NISHINOMIYA Supply System City ⑤ ④ ASHIYA City ① NUNOBIKI KARASUHARA HANSHIN AKASHI Water City ①＋River E.P.C : Emergency contact pipe ①＋NUNOBIKI FIG.-3.The duplication of Transmission Facilities and Water Sources There are two different transmission facilities, one is a mountain tunnel and other is a steel pipe in a shield tunnel, therefore the redundancy of transmission function improves greatly in terms of route and structure type. LCTM also has a storage function, so emergency water would be supplied in the urban area. Like this, we promote to make the dual transmission facility and to supply water from the different source as possible. For example, we constructed the connection pipes between downtown area and a part of the northern area of ROKKO mountain chain. As a result, we could decrease the running cost in comparison with the watering from the self-source in the distance. The distribution reservoirs and other main facilities (such as reservoirs, conveyance and distribution tunnels, purification plants and pump facilities) must have substitution function in times of disaster and renewal. We have been creating "the water supply system reliability evaluation program" which decides the priority of renewal and seismic upgrading by evaluating the reliability of the water supply system. As well as the distribution pipe network, the elements of evaluation consist of the influence degree to consumers at the time of the disaster, existence of substitution functions, and so on. At present, we define the accident rate and water volume of each facility as the influence degree. We will modify this influence degree by considering the capacity of distribution reservoir or the availability of backup system, for instance. Moreover, we are carrying out the diagnosis on the resistance to the disaster and deterioration about the pond-shaped structure. We are eager to improve the accuracy of this program. 144 ・Aging (Distribution block) Reservoir ・Seismic Backup function Upgrading ・Flux Pump place P P Network Joint Well Analysis Purification Transmission tunnel Plant Distribution Reservoir At Suspension of water supply ・probability ・population (Distribution block) LCTM Fig. 4.The Image of Water supply system Reliability Evaluation Program ４． Disaster Mitigation 1) Policy on Emergency Watering We have promoted to construct the emergency storage systems, as well as the seismic practices of the pipeline and the main facilities. There were 18 systems which had already been completed at the time of the disaster, and emergency water of about 42,000㎥could be secured. The water supply was carried to the emergency stations such as parks and schools by trucks. And, we received emergency water of about 2,200㎥ per day at the end of the water pipe network, through two emergency contact pipes between Kobe City and the neighboring water suppliers. Since these policies were proved to be very effective, these facilities have been prepared actively in addition to LCTM that had storage function. We have a plan on the emergency storage system that is constructed at the rate in every 2km radius from the system because of efficient conveyance of water supply trucks. The number of this system is 47 to cover the whole city. 37 systems are completed at present, and emergency water is secured about 54,000㎥. Table-Ⅱ. THE SECURING AMOUNT OF EMERGENCY SUPPLY WATER 〔㎥〕 Facilities Securing Amount at Present Reference (㎥) Large Capacity Transmission Pipe 17,000 L=3. 8km The final: 59,000㎥ Emergency Storage system 54,000 37 places The final: 47 places Other Water Tank 1,700 5 places Emergency Contact Pipe 8,800 7 places 5 cities, per day 145 As the author mentioned before, emergency watering is supposed to be done by the water supply trucks right after the disaster. After the water pipes are confirmed restoration in series, emergency watering is done with "An emergency hydrant" like a fire hydrant in the road near the residence. This is prepared every 500m in the main distribution pipe of φ 300mm and more. 2) Mutual Aid We could have an aid from the neighboring government right after the disaster, and an emergency contact pipes between neighboring water suppliers were effective, because the suffering range was comparatively limited. And there are 10 mutual aid agreements for disasters with other local governments. Suffering is predicted extensively with the ocean type great earthquake that will be expected to occur in the near future. In such occasion, the neighboring governments also may suffer, and we may not be able to expect an aid from them. Therefore, it is very important to have a mutual aid agreement among 15 large cities in Japan. In case of Kobe City, Osaka City and Hiroshima City are assigned as the mutual aid city. ５． New Strategy of Public Relations “ITSUDEMO-JAGUCHI” 1) Purpose We have promoted seismic practices of the facilities and securing of the backup function, because we should enhance the stability of the whole water supply system. Especially, the seismic practices of the distribution pipes toward the schools and the emergency hospitals were being carried out preferentially. As for the progress of those seismic practices, we make public by the public relations community papers and our website, and so on till now. Moreover, some of our staff members have explained those progresses to the students at schools as “a delivery service talk", and the citizen through the emergency water training. The water supply facilities are away from the city area, and the pipeline is installed under the ground. Consequently, it is said that the citizen doesn't know the progress of seismic practices on the water supply system, even though those facilities are earthquake-resistant. We investigated the needs of customers last September. This investigation says 86% was eager for the seismic practices of the water supply system, but only 28% recognized the actual state of them. On the other hand, the citizen understands the seismic practices of the school building, because they can see the reinforcement with some braces visually. Therefore, we are planning to install "ITSUDEMO-JAGUCHI." as a symbol of our seismic practices at five elementary schools every year from now. We want to make the citizen to notice the progress state of seismic practices on the water supply system. That is a drinking fountain with a function as an emergency water tap at the time of disaster. The emergency water can be served right after the disaster with this facility, so we call this "ITSUDEMO-JAGUCHI", that means the faucet which supplies water anytime even though it’s the early stage of disaster. 146 2) Outline of Plan It is no wonder that the water usually comes out from the faucet in daily life, but the citizen never know the worth of water till a disaster or an accident happens to occur. We promote seismic practices on the distribution pipes toward the emergency stations. That is, we have replaced the aged pipes to the earthquake-resistant pipes between the distribution reservoir and the emergency stations perfectly. But, since the total extension of the distribution pipes is so long, the rate of those pipes is only 22%. We decided to make the distribution pipes to the elementary school earthquake-resistant. Kobe Water constructs the earthquake-resistant pipe to "ITSUDEMO-JAGUCHI", that is a drinking fountain adopted universal design at the elementary school playground. We prepare it at the corner of the school playground to catch the notice of the students and the citizen. A temporary water stand is stored in the emergency school warehouse. If the local residents connect it to an emergency tap of "ITSUDEMO-JAGUCHI", watering becomes possible right after the disaster. We set up the signboard explaining its purpose with the local residents cooperatively. Distribution Reservoir Distribution pipe Itsudemo- jaguchi Fig.-5.The Outline of “ITSUDEMO-JAGUCHI” 147 3) Effects The purpose of "ITSUDEMO-JAGUCHI" is to make the citizen to notice the actual progress state of seismic practices on the water supply system. And, we expect to promote a risk communication with the citizen. In addition to that, the following effects can be expected. (1) The closer emergency water system can be built up right after the disaster, because emergency watering is possible at the elementary school that is a close place to the residence. Emergency watering activity by the tank cars can be mitigated. (2) The emergency watering activities by the area inhabitant become possible, so our staff members can devote themselves to the restoration of the water supply system. The early restoration of the water supply system is expected. (3) We can make the students and the residents notice the safety and freshness of the tap water, because this tap water is supplied from the distribution reservoir directly. (4) As most of elementary schools have water storage tanks. We can have an opportunity to make the schools change to the water supply system without storage tanks, because Kobe Water installs "ITSUDEMO-JAGUCHI" and bears the cost of it. (5) It is expected that the maintenance of the facility and the training on the emergency watering by the resident promote revitalization and nurturing of local communities. (6) A suffering experience can be acceded to the next generation through the disaster prevention education. As the author mentioned before, we can expect a lot of effects by "ITSUDEMO-JAGUCHI". We think it is a very effective and strategic means of the public information for the water supply activity. In Kobe City, the temporary rest rooms connected with the public drain directly are been constructing one after another, but those must use water of the swimming pool and rainwater at the emergency stations. We should collaborate with the strategic on sewage and other emergency policies at the elementary school. As a result, we can make the elementary schools be the integrated emergency stations. We will have a total plan by connection with the related departments and organizations. ６． Conclusion Kobe Water must keep supplying safe water from the source to the faucet, for this reason, we are making up "a water safety plan" about YODO River and SENGARI reservoir at present. In addition, we must improve the whole stability of the water supply system, and supply water to the citizen steadily as a lifeline, because it is predicted that large earthquakes will occur, frequently. Those are our missions as the water supplier. But, seismic practices do not contribute to the profit of the water supplier directly, so that we should consider in the finite budget and take the priority for them in accordance with the renewal systematically. It is very most important to enforce seismic policy with the new knowledge that could be acquired from some large earthquakes after HANSHIN- AWAJI disaster, too. If some large earthquakes happen to occur simultaneously in NANKAI area like SUMATRA, it might be suffering such as water salination of river around intake facilities by large-scale TUNAMI. We must keep on enforcing a policy on the disaster mitigation with related organizations with the latest knowledge. 148 We also recognize the mutual aid is very important in times of disasters and accidents. There were only a few casualties, and the quick reconstruction was completed in some communications in those the mutual aid of the inhabitant was active at HANSHIN-AWAJI disaster. "Communities for disaster prevention and welfare" have been established based on that lesson by every elementary school in Kobe city. The number of them is 190 for 169 schools. We think it is important to announce accurate information to the citizen for effective use of the facilities. And, the emergency training on a routine basis is indispensable for rapid correspondence in times of disasters and accidents. We regard "ITSUDEMO-JAGUCHI" as the symbol of seismic upgrading policy. We will use this facility as a tool of the risk communication with the citizen whose experience on the disaster is fading away. Kobe Water believes it can make the disaster mitigate further to share the accurate information and our recognition with the citizen. ７． ACKNOWLEDGEMENT The support from the Technical Department of Kobe Water is gratefully acknowledged. Especially Mr. M. Matsushita, Mr. M. Tanaka and Mr. H. Hayashi gave some information and helped to prepare the data. 149 150 REGIONAL ECONOMIC ANALYSIS OF EARTHQUAKE LOSSES, MITIGATION AND RESILIENCE by Adam Rose* I. INTRODUCTION The geographic scope of the economic impacts of most natural and man-made disasters in the United States is regional rather than local or national. This is not to diminish the individual suffering or the national concern. It stems from the fact that even local impacts ripple spatially to the boundaries of larger economic trading areas. It also stems from the vast size of the U.S. and the limits of man-made and even natural forces. Thus, the appropriate geographic area for analysis is often the county or county group, though not necessarily within the boundaries of a single state. A major earthquake on the San Andreas Fault is no exception. A factor that extends disaster losses beyond the area of the initial stimulus is the interdependence of the economy. One view of interdependence is the production pyramid, which characterizes the economy as consisting of layers of building blocks. Primary commodities, such as minerals, agricultural crops, and forest products, are at the foundation of this economic edifice because they are at the starting point of the production process. Intertwined with all the layers are roads, utilities, and communication networks that provide the lifelines of logistic support for even the most basic economic activity. Thus, all goods and services in the economy are interdependent, but infrastructure may be the most critical. But infrastructure is not necessarily best characterized by the rigidity of road, pipeline, or transmission networks. Instead, it possesses features of resilience, or flexibility and the ability to rebound. The purpose of this project will be to analyze the economic impacts of a major earthquake on the San Andreas fault. The study will utilize the results of research by geologists, geographers and engineers on the spatial pattern of damage to the built environment. It will then translate these property damage (or stock loss) estimates into business interruption (or flow loss) estimates at the regional level. The analysis will be based on the use of input-output (I-O) analysis, still the most widely used tool of regional economic impact analysis, and computable general equilibrium (CGE) analysis, a state of the art approach that captures most of the advantageous features of I-O and overcomes many of its limitations. Both of these modeling approaches are adept at tracing economic interdependencies that can cause total regional economic impacts to be several times greater than direct impacts. II. ECONOMIC INTERDEPENDENCE One way economists illustrate interdependence is through the simple circular flow diagram presented in Figure 1. In factor markets, households offer labor and capital to businesses in exchange for income payments. Businesses then use these “Primary Factors” to produce goods and services to sell to households. 151 This simple version of the economy, however, does not adequately reflect many aspects of the interdependence of the economy, but it can be made effective in this regard by adding more detail as presented in Figure 2. At the far left of this figure, we first acknowledge that businesses do not just use labor and capital to produce goods and services, but also need various types of raw and processed materials, as well as various services, which are all referred to as “Intermediate Goods.” Infrastructure is a subset of this category of intermediate goods and in a fundamental way, since it is required by all businesses. Purchase of infrastructure services by households would be part of the “Business Production of Final Goods and Services,” though this implicitly includes government production of priced infrastructure services as well. A large amount of infrastructure, especially roads, bridges, and in some cases airports and waterports, are not purchased in a market. These would be part of the box in the lower right hand corner labeled “Unpriced Inputs”, and includes environmental services as well. Note that one of the advantages of CGE models to be discussed below is the ability to calculate efficient prices for these infrastructure services under normal and hazard-event circumstances. Another feature of Figure 2 is an extension of the activities of households to include ways that they can combine market goods and services with time and household resources to yield “household production,” such as cooked meals, recreation, etc. This enables us to estimate the value of infrastructure service to households, especially those not transmitted through the market. This is important in that households typically purchase between thirty and forty percent of water and electricity. If they need to cope with a disruption through the substitution of other inputs, use of their leisure time, or if they suffer inconvenience, these responses are not normally reflected in formal economic (income and product) accounts. However, this reflection of market failure (or the absence of markets in the first place) should not be construed as lack of value for infrastructure services, but rather failures and biases in the way most informal economic activities are evaluated. Again, this extended formulation enables us to find implicit prices for infrastructure and environmental services and to measure a reduction in their service flows as a type of household economic interruption, in addition to the lost wages/salaries, dividends, rents, and royalties that can be computed with most existing models. III. ECONOMIC MODELS OF INTERDEPENDENCE In this section, we summarize the two major modeling approaches to regional economic impact analysis. We focus on insights they yield on regional economic interdependence. A. Input-Output Analysis Input-output can be defined as a static, linear model of all purchases and sales between sectors of an economy, based on the technological relationships of production (see, e.g., Rose and Miernyk, 1989). Essentially, this is a detailed, comprehensive, double-entry bookkeeping record of all production activity. Practically every country in the world has constructed an input-output table, usually through an exhaustive census or at least an extensive survey, and there is a rich literature on ways to use non-survey data-reduction, or “down-scaling,” methods to generate tables for political jurisdictions at various sub- national levels. Table 1 presents an aggregated version of the Los Angeles County Input-Output Table. This table originally consisted of more than 500 sectors, but these have been aggregated for display purposes, while maintaining infrastructure sectors at a reasonably disaggregated level. 2 152 business revenues Markets payments goods & services Goods & goods & services Services Businesses Households Production of Consumption Final Goods Of Goods & Services & Services payments to factors Markets household income factor inputs Factors of labor & capital Production FIGURE 1. BASIC CIRCULAR FLOW OF THE ECONOMY payments for goods & services goods & services for household production business revenues Markets payments household intermediate goods & services Goods & goods & services goods & services Services goods & services Businesses Businesses Households Households Production of Production of Consumption Production of Intermediate Final Goods of Goods Goods Goods & Services & Services & Services & Services payments payments to factors household income Markets factor inputs Factors of labor & capital shadow prices Production labor & capital opportunity costs service flows payments to factors factor inputs Unpriced Inputs Infrastructure & Environment FIGURE 2. EXPANDED CIRCULAR FLOW OF THE ECONOMY 3 153 TABLE 1. 2002 LA INPUT-OUTPUT TABLE (in million dollars) 1 2 3 4 5 6 7 8 9 Row Sector Agri- Mining Construction Electric Gas Water & Manufac- Trade Transpor- # culture Utilities Utilities Sanitary turing tation Utilities 1 Agriculture 1.5 0.0 1.4 0.0 0.0 0.0 133.3 0.0 0.0 2 Mining 0.1 80.7 48.4 264.1 435.8 0.0 1,404.6 0.0 17.4 3 Construction 0.8 0.2 32.4 191.6 2.1 15.2 309.2 210.2 106.3 4 Electric Utilities 2.3 36.1 85.0 0.5 1.5 2.1 1,353.1 572.7 139.9 5 Gas Utilities 0.2 0.9 22.0 0.0 0.0 1.4 650.3 93.7 40.5 6 Water & Sanitary Utilities 0.1 0.2 1.8 3.7 0.1 0.0 2.0 4.7 2.2 7 Manufacturing 18.7 108.2 4,301.5 175.0 25.4 4.8 27,736.6 1,193.5 1,750.8 8 Trade 7.0 28.7 2,641.5 44.8 5.3 2.2 7,974.3 1,192.8 817.2 9 Transportation 2.9 25.8 395.0 266.6 364.9 0.8 2,774.5 960.3 2,326.5 10 Communication 0.2 1.2 110.5 2.6 0.6 0.8 262.5 283.9 172.5 11 Information 0.1 1.2 28.6 10.5 0.1 0.1 596.4 202.3 75.0 12 Finance, Ins, Real Estate 12.3 28.5 553.4 104.8 29.1 2.0 2,001.4 2,625.6 1,005.9 13 Services 5.1 323.4 2,133.4 271.3 58.3 8.4 10,258.8 6,873.6 2,872.1 14 Government 0.0 0.2 45.9 0.5 0.8 0.0 461.6 100.4 48.5 15 HH 318.9 667.0 11,197.9 1,207.6 565.3 93.0 30,994.0 29,306.3 12,035.6 16 OVA 12.8 774.4 1,161.4 6,168.9 605.2 69.7 13,306.2 21,333.1 1,937.4 17 Imports & Other 61.3 311.9 2,871.6 908.0 1,180.9 5.2 23,925.0 3,387.8 3,140.8 OUTPUT 444.4 2,388.5 25,631.6 9,620.4 3,275.5 205.6 124,143.6 68,340.9 26,488.7 10 11 12 13 14 15 16 17 Row Sector Commun- Infor- Finance, Ins, Services Govern- Household Gov't FD Other FD OUTPUT # ication mation Real Estate ment 1 Agriculture 0.0 0.0 1.5 12.7 0.0 48.8 2.7 242.5 444.4 2 Mining 0.0 0.0 6.3 1.2 39.1 1.2 9.8 80.0 2,388.5 3 Construction 80.1 99.4 917.9 1,036.2 411.4 0.0 3,542.3 18,676.4 25,631.6 4 Electric Utilities 66.3 149.1 851.9 1,468.2 210.1 3,256.6 767.6 657.4 9,620.4 5 Gas Utilities 13.8 17.7 135.2 366.0 7.6 1,355.6 254.3 316.3 3,275.5 6 Water & Sanitary Utilities 2.5 1.3 12.9 28.8 12.3 117.9 13.7 1.5 205.6 7 Manufacturing 482.3 2,306.3 800.7 9,390.6 561.6 29,664.6 8,033.1 37,589.9 124,143.6 8 Trade 107.4 862.0 737.0 3,631.1 156.7 37,261.7 857.6 12,013.5 68,340.9 9 Transportation 103.5 537.9 666.5 2,183.6 128.5 3,908.4 610.3 11,232.9 26,488.7 10 Communication 1,830.4 379.9 273.0 1,146.0 24.7 3,547.4 377.6 10,936.5 19,350.4 11 Information 528.6 2,617.5 209.3 1,245.2 17.4 1,941.1 322.1 31,194.1 38,989.6 12 Finance, Ins, Real Estate 303.2 1,096.5 14,953.5 9,572.3 237.8 40,626.7 1,381.9 32,589.2 107,124.2 13 Services 1,928.8 4,911.6 7,016.2 20,111.2 673.4 72,946.2 32,308.4 47,627.6 210,327.7 14 Government 27.1 132.4 197.5 518.9 242.4 1,267.6 3,091.9 7,733.9 13,869.4 15 HH 4,928.0 17,072.4 22,180.7 119,592.2 4,922.3 16 OVA 6,419.3 4,712.3 51,012.1 26,403.8 5,473.9 17 Imports & Other 2,529.1 4,093.3 7,152.1 13,619.7 750.2 49,605.1 10,035.5 33,294.7 (156,827.2) OUTPUT 19,350.4 38,989.6 107,124.2 210,327.7 13,869.4 245,548.8 61,608.6 244,186.3 650,200.4 4 154 The sectors of the economy are labeled in the left-hand column as sellers of goods and services, and labeled at the top of the table, in the same order, as buyers. Looking across Row 4, we see a tabulation of the dollar value of the services of Electricity Utilities sold to every other sector. Services and Manufacturing are the two main business users of electricity, but note the largest single category of buyers is households, accounting for more than one-third of electricity sales. The Electric Utilities column shows the dollar value of various inputs needed to produce this valuable good. Row 4 also intersects other infrastructure types—Water and Sanitary Services, Transportation (there is now an electricity-driven light-rail system in LA), Communication, and Information.1 Disaggregated cells in a given row provide us with valuable, detailed information on customer usage, which is often not available through the fairly aggregated categories reported by utilities (industrial, commercial, and residential sales). The intersection of the various infrastructure rows and columns gives us valuable information on the interdependence of utility lifelines and helps us identify and prevent various types of cascading failure, as in the Northeast Electricity Blackout of 2003 and Hurricane Katrina. One of the novel features of an I-O table is the fact that it can be readily transformed into a model by assuming a fixed relationship between inputs and outputs. This translates into the assessment that if a factory is cut off from 25 percent of its electricity, it will, at first pass, be forced to reduce its output by 25 percent.2 Interdependence is readily portrayed in this double-entry bookkeeping tabulation of Table 1. Also, we can formally measure it by identifying and calculating backward and forward linkages between all sectors. If a sector affected by the electricity outage reduces its production by 25 percent, we say this is a direct business interruption (BI) effect. (Note also that this result can take place even if the factory property is unscathed by an earthquake or terrorist attack, as long as its lifeline service is disrupted.) Because the factory then reduces its order for each input by 25 percent, the firms producing those inputs in turn will do the same, as well their suppliers, and so on, as the original perturbation ripples through the economy. The sum total of these ripples is some multiple of the original shock; hence, the origin of the term “multiplier” effect. We could go through a tedious process of calculating these chains of indirect and induced3 effects. However, there is a simple matrix inversion procedure that calculates all the interactions in a manner analogous to finding the sum of an infinite series. This “total requirements” matrix consists of entries that tell us the total amount of each sector’s output needed directly and indirectly per net unit of production of a given good or service. The column sum for every good is its output multiplier. This helps determine the ripples that electricity outages can cause. By examining individual cells, we can see how much of this is caused by disruption to other types of infrastructure. Of course such computations need to be complemented by sound engineering analyses of infrastructure networks (see, e.g., O’Rourke et al., 2004; Shinozuka and Chang, 2004). This is enhanced by GIS overlays of the networks onto the economy (see, e.g., French, 1998; Rose and Liao, 2005). I-O models thus provide a great deal of basic information, insight, and computational ability. They also have significant limitations, such as linearity, absence of behavioral considerations, absence of markets and prices, and lack of formal constraints. Still, I-O models are useful in providing ball-park estimates of very short-run responses to infrastructures disruptions. They can readily be transformed into LP models for optimization analysis (see, e.g., Cole, 1995; Rose et al., 1997), extended to CGE models to capture behavioral considerations and the role of markets (see, e.g., Rose and Liao, 2005) and incorporated into integrated systems models, where, because of model scale and computational manageability, a simplified economic model may be preferred (see, e.g., Cho et al., 2003; Gordon et al., 2005). Sophisticated versions of I-O models incorporating dynamic elements are very valuable as well (see, e.g., Haimes et al., 2005). 5 155 B. Computable General Equilibrium Analysis Computable General Equilibrium can be defined as a multi-market, non-linear model of individual behavioral response to price signals, subject to limitations of labor, capital and natural resources (Shoven and Whalley, 1992). Essentially, CGE incorporates all of the best features of I-O models (e.g., comprehensive accounting of all inputs, interdependence of economic agents and activity) and overcomes most of their limitations (linearity, lack of behavioral content, absence of markets of prices, and lack of constraints) (Rose, 1995). Of course, these advances come only at the expense of increased theoretical complexity, heightened data needs, and more demanding operation. Thus, the use of CGE models, though increasing rapidly, is still nowhere as extensive as I-O models, especially at the regional level, where data are especially sparse (Partridge and Rickman, 1998). CGE models have at their heart an I-O table, such as Table 1, that depicts the role of all inputs into production of economy. However, this extends one dimension further to a social accounting matrix (SAM) that provides sets of accounts for households (often disaggregated by socioeconomic category, such as income or race/ethnicity) and various other types of institutional accounts relating to savings, government taxes and transfers, and trade with the outside world. Production relationships are more flexible than in an I-O model, allowing for the substitution of at least major aggregates of inputs in response to price changes.4 Household behavior can be modeled in a number of ways that are superior to the fixed shares of consumption in the I-O model. This includes the household production function formulation, which portrays households combining purchased goods and services along with time to provide final products for consumption, such as cooked meals, recreation, etc. (Pollak and Wales, 1992; Oladosu, 2000). This provides a basis for estimating the value of unpriced infrastructure services as noted in Section II (see also Rose and Oladosu, 2007). CGE models can also incorporate relatively more sophisticated government sector and interregional/international trade components than can I-O models. CGE models are best suited to long-run analyses (at least one year or more) during which all factors of production can adjust to a new equilibrium. They need to be modified to be applicable to the short run, and even more so for the very short run of adjustments to disasters. This is done in a number of ways (see, e.g., Rose and Liao, 2005).5 First, the ease at which one input can be substituted for another can be reduced to reflect the more limited options available in the immediate aftermath of an earthquake or other disaster. It can also be supplemented by explicit disequilibrium closure rules, which reflect key account balances in labor, capital and goods markets, government activity, and trade. Examples include explicit constraints on infrastructure service availability, allowing less than full employment equilibria, government deficit spending, and trade imbalances (see Rose et al., 2007). CGE models provide unique insight into infrastructure interdependence. Not only can they reveal quantity interdependence, as in how the loss of electricity services might reduce the availability of water services, but they can also provide insights into basic pricing and price interdependence. Some infrastructure services (e.g., highways and bridges) do not have market prices associated with them, but a CGE model can impute “shadow,” or efficient value of use, prices to them. Many other infrastructure services (especially water, and, still to some extent, electricity) are priced but by regulatory bodies and not by markets. These prices would not or could not normally be adjusted according to market conditions of increased scarcity in the immediate aftermath of a disaster. CGE model results, however, could be used to guide any short-term price adjustments to promote efficient allocation of resources explicitly through markets or implicitly through non-price rationing. More generally, the CGE model can compute the extent to which the quantity and price change in one type of infrastructure can affect the quantity and price of another type, as well as the quantities and prices of all goods and services in the economy (see, e.g., Rose and Liao, 2005). 6 156 Overall, CGE models are able to estimate a broader set of indirect effects of external shocks than are I-O models. In addition to ordinary (quantity interdependent) multiplier effects, CGE models can capture the associated effects of cost and price adjustments of interdependent markets—this is the essence of the meaning of the term “general equilibrium.” These models are also much more adept at analyzing an even broader set of effects relating to “tipping points,” or discrete changes associated with reaching threshold values. One example would be the shutdown of marginal (weak) businesses following an earthquake. This might be associated with a given level of property damage or loss of function (say, 80% of either indicator) that would lead to the permanent closure of the enterprise. CGE models can also incorporate the positive effects of resilience, as well as the dampening effects of the erosion of resilience (see below). Yet another category of losses may stem from behavioral linkages (see Rose, 2006). They relate to the social amplification of risk through media hype or rumor about such things as the spread of disease from contaminated water. This spreads fear and can lead to such things as averting behavior (e.g., employees staying home rather than journeying to the workplace). This phenomenon can be formally incorporated in the production function of businesses and the utility functions of households within a CGE model by using abounded rationality approach (see Burns et al.). In contrast to the tipping point phenomenon, which relates primarily to longer-run impacts, risk amplification effects are of a shorter duration. The CGE model can capture both, given accurate input data. In essence, CGE models reflect all of the components and workings of the economy depicted in Figure 2. In contrast, I-O models do not include the unpriced infrastructure and environmental services, and the “workings” are through a mechanistic set of fixed proportional requirements rather than the full interplay of market interactions. IV. DEFINING, MEASURING AND MODELING RESILIENCE Resilience refers to the ability of individuals, markets, and the economy as a whole to continue functioning when shocked by a disaster (see, e.g., Holling, 1973; Perrings, 2001; Rose, 2004; Rose 2007b). A more general definition that incorporates dynamic considerations, including stability, is the ability of a system to recover from a severe shock. Resilience emanates both from internal motivation and the stimulus of private or public policy decisions (Mileti, 1999). Also, resilience, as defined in this paper, refers to post-disaster conditions and response, which are distinguished from pre-disaster activities to reduce potential losses through mitigation. In disaster research, resilience has been emphasized most by Tierney (1997) in terms of business coping behavior and community response, by Comfort (1999) in terms of non-linear adaptive response of organizations (broadly defined to include both the public and private sectors), and by Petak (2002) in terms of system performance.6 These concepts have been extended to practice. Disaster recovery and business continuity industries have sprung up that offer specialized services to help firms during various aspects of disasters, especially power outages (see, e.g., Salerno, 2003). Key services include the opportunity to outsource communication and information aspects of the business at an alternative site. There is also a growing realization of the broader context of the economic impacts, especially with the new emphasis on supply chain management. One company executive recently summarized the situation quite poignantly: “In short, companies have started to realize that they participate in a greater ecosystem—and that their IT systems are only as resilient as the firms that they rely on to stay in business” (Corcoran, 2003; p. 5). Experience with Y2K, 9/11, natural disasters, and technological/regulatory failures, as well as simulated drills, have sharpened utility industry and business resilience (Eckles, 2003). Similar activities of public agencies have improved community resilience. 7 157 Resilience can take place at three levels: Microeconomic--individual behavior of firms, households, or organizations. Mesoeconomic--economic sector, individual market, or cooperative group. Macroeconomic--all individual units and markets combined, including interactive effects. Examples of individual resilience are well documented in the literature, as are examples of the operation of businesses and organizations. These include the ability to substitute for inputs in short supply, conserve, use inventories, and reschedule lost production for a later date by working overtime or extra shifts. What is often less appreciated by disaster researchers outside economics and closely related disciplines is the inherent resilience of markets. Prices act as the “invisible hand” that can guide resources to their best allocation even in the aftermath of a disaster. Some pricing mechanisms have been established expressly to deal with such a situation, as in the case of non-interruptible service premia that enable customers to estimate the value of a continuous supply of electricity and to pay in advance for receiving priority service during an outage (Chao and Wilson, 1987). The price mechanism is a relatively costless way of redirecting goods and services. Price increases, though often viewed as “gouging,” serve a useful purpose of reflecting highest value use, even in the broader social setting. Moreover, if the allocation does violate principles of equity (fairness), the market allocations can be adjusted by income or material transfers to the needy. CGE models are capable of decomposing a price increase into that portion that is warranted by increased scarcity and that portion that is simply gouging. Will an X percent loss of electricity result in an X percent direct loss in economic activity for a given firm? The answer is definitely “no” if economic resilience is present. For the purpose at hand, we use as our measure of direct resilience, the deviation from the linear proportional relation between the percentage utility disruption and the percentage reduction in customer output (see Rose, 2004). Will a Y percent loss in direct output yield much larger general equilibrium losses? Here market- related adjustments suggest some muting of general equilibrium effects, if we measure market, or net general equilibrium, resilience as the deviation from the linear multiplier effect that would be generated from a simple I-O analysis of the outage (Rose, 2004). Adjustments for lost output of goods and services other than electricity include inventories, conservation, input substitution, import substitution and production rescheduling at the level of the individual firm, and the rationing feature of pricing at the level of the market. How significant is resilience in practice?7 Rose and Lim (2002) in their interpretation of Tierney’s (1997) survey of businesses following the Northridge earthquake inferred a direct business resilience of 77.1 percent to electricity disruptions. Various studies by the author using both I-O and CGE models in cases of utility service disruptions (water in the aftermath of a hypothetical earthquake in Portland, Oregon, and electricity disruption in a hypothetical New Madrid earthquake and the Northridge Earthquake in Los Angeles) found direct business resilience to be between 85 percent and 95 percent.8 These same studies found market resilience to range between 50 percent and 80 percent. This means that omission of resilience factors can lead to an overestimate of BI losses by factors as high as five to ten.9 Resilience can be enhanced in several ways: increasing inventories, contracting with back-up IT providers, holding emergency planning drills to enhance experience in adapting to crisis situations, etc. On the other hand, resilience can be significantly eroded, as evidenced by the recent Hurricane Katrina 8 158 experience. For example, production rescheduling may not be feasible if functionality is not restored within 6 to 9 months, owing to a permanent loss of customers. As noted above, resilience can be incorporated into both I-O models (see Rose and Lim, 2002; FEMA, 2005) and CGE models (see Rose and Liao, 2005; Rose et al., 2007). In the CGE model, incorporation is less ad hoc, in that resilience adjustments relate directly to production function parameters (e.g., elasticities of substitution and productivity terms). Moreover, CGE models are able to include a broader range of resilience responses than I-O models, including input substitution and market resilience as a whole. V. DATA UNDERPINNINGS No model is any better than the data on which it is based. An obvious issue then is the data intensity of the models just described. Unlike most conventional economic approaches that simply relate output to primary factors of production—capital, labor, and sometimes natural resources—I-O and CGE models account for all inputs, including intermediate, or processed goods and services. Moreover, they do so at a level of sectoral detail that exceeds that of more standard econometric models. Fortunately, the developer of I-O, Nobel laureate Wassily Leontief, placed a great emphasis on sound empirical construction of these models. He insisted they be based on primary data collection, and he championed such efforts at the federal and later the state and local levels. In fact, the U.S. I-O Table is prepared by the U.S, Department of Commerce from the voluminous data collected in the Census of Manufacturers and the censuses for other major sectors of the economy. Regional level tables present a great challenge, because it means collecting similar, though less extensive, data 50 times over at the state level and more than 2,500 times at the county level. It is not sufficient to take national data and simply apportion it to smaller geographic areas, because the origin and destination of the flow of goods is critical. A regional economy can only be stimulated by increases in demand for its own products, rather than for imports, so two types of flows need to be distinguished. The expense of constructing a regional I-O table from primary data would cost several million dollars for even a small state. Accordingly, data reduction methods (also known as non-survey or down-scaling) are the typical approach used to generate state and county tables. These methods usually involve four steps: 1) specifying control totals for sectoral production, assuming the structure of production (input coefficients) are the same in the region as for the nation as a whole, 3) estimating intra-regional production vs. imports, and 4) various ad hoc adjustments for differences between regional and national technologies. The U.S. Department of commerce produces county and state tables through its Regional Input- Output Modeling system (RIMS). However, the most widely used source of regional I-O tables these days is the Impact Analysis for Planning (IMPLAN) System (MIG, 2006). This consists of three components: 1) a county level data base, 2) a set of algorithms capable of generating I-O tables for any county or county group, and 3) a computational capability for calculating multipliers and performing impact analyses. The LA I-O table above is an aggregated version of the 528 sector IMPLAN table for that county. Other data are critical for evaluating disaster impacts and resilience. These include data on the built environment (factories, residences, infrastructure) and the natural environment. Also ideal would be a set of damage functions that relate changes in underlying conditions to property damage and loss of function. One such source is FEMA’s Hazards United States-Multi-Hazard (HAZUS-MH) (FEMA, 9 159 2005). This is a large expert system that contains detailed data on the built environment at the small area level, a set of damage functions, and a GIS capability. Physical damage and business down-time are translated into direct dollar values, and an imbedded I-O capability allows the user to calculate multiplier effects under various circumstances including resilience. HAZUS, including the Indirect Economic Loss module (IELM), can be run at 3 level: 1) a set of default values or national averages, 2) openings for region-specific data, including the importation of IMPLAN I-O tables, and 3) customized data. Finally, more data are needed to evaluate economic resilience. Recent modeling innovations have been made (see, e.g., Shinozuka and Chang, 2004; Rose and Liao, 2005; and Haimes et al., 2005), but empirical work lags behind. A strong basis in this area is the survey work by Tierney (1997), which can be further refined for a variety of applications (see, e.g., Rose and Lim, 2002). Additional data collection and refinement efforts by the author and his associates have helped specify resilience factors for production rescheduling (these have even been integrated into the HAZUS Direct Economic Loss Module as “recapture factors”), for distributed power generation, and for water storage. Publications by the U.S. Department of Commerce on excess capacity and inventories can also be used. Expert judgment has been tapped to evaluate “importance,” or that part of a business’s operations that require a certain type of infrastructure service (ATC, 1990). Algorithms have been developed by Rose and Liao (2005) to use existing data to fill in the gaps on resilience responses and to change model parameters accordingly. Still, there is much to be done because resilience differs by type, sector and geographic location. More recently, Rose (2007a) has pointed out how resilience differs by scope, magnitude, and duration of a disaster, e.g., how Hurricane Katrina illustrated how resilience can be eroded. At the same time, resilience can be enhanced by investment, information dissemination, and advanced planning. Resilience represents a relatively low-cost way of reducing the consequences of a disaster. Several resilience actions are low-cost or pay for themselves ( e.g., conservation and production rescheduling). In general, they are cheaper than mitigation to a great extent because most need not be implemented (paid for) until the disaster is certain. All of this supports the high priority that should be accorded to the collection of more data at the regional level, and not just for businesses, but also for households, and for communities as a whole. VI. CONCLUSION The models presented here are capable of estimating not only the apparent direct effects but also the regional indirect, or interdependence, economic effects of earthquake damage. An additional important feature of the models is their ability to calculate the full range of economic benefits (avoided losses) of hazard mitigation and resilience. The application of these models can help identify the lowest cost strategies for reducing economic losses. Most prior analyses have focused on mitigation, but the newer concept of resilience warrants attention. Some resilience options are relatively low cost (e.g., production rescheduling), some may even be cost-saving (conservation), and most of them need not sit idly in anticipation of an event, but can be marshaled when needed. Though many high level policy- makers do not want to admit the fact, it is impossible to protect the general population against all natural disasters and terrorist attacks. Analyses such as those highlighted in the previous sections provide guidance to how individuals and firms, however, can help protect themselves from the negative impacts of business and infrastructure disruptions. Thus, in benefit-cost analyses of ways to reduce losses from disasters, there is a need to take a holistic view of trade-offs between mitigation and resilient responses, both of which can significantly result in cost-savings to society as a whole. In the same vein, it is important not to neglect regional economic interdependence effects, including the potential negative effects of the failure of one type of 10 160 infrastructure upon others. Such interdependencies can significantly raise the stakes at risk. The models presented in this paper can provide reasonable estimates of these complex considerations. 11 161 ENDNOTES * The author is Visiting Professor of Policy, Planning and Development, and Coordinator for Economics at the Center for Risk and Economic Analysis of Terrorism Events, University of Southern California, Los Angeles, CA (on leave from the Department of Geography, The Pennsylvania State University, University Park, PA). He wishes to acknowledgement the support of the DHS Center for Risk and Economic Analysis of Terrorism Events (CREATE) and the Multidisciplinary Center for Earthquake Engineering Research (MCEER) in the writing of this paper. 1 Note that Transportation can be further divided into private and public and by mode (e.g., surface, truck, rail, air, water). Likewise, Communication networks are further disaggregated in the 500 sector classification scheme. 2 Mathematically, this is done by dividing each cell in a given column by its column sum. This provides us with a “structural,” or normalized, set of coefficients that reflect the cents’ worth of each input needed to produce a dollar’s worth of output of a given sector. 3 The effects stemming from the reduction of household income are referred to as “induced” effects. 4 Often, components of the material aggregate (consisting of all the intermediate goods) are assumed to be allocated in fixed proportions, but substitution is allowed between the aggregate material category and capital and labor. 5 Interestingly, the inflexibility of I-O models makes them more appropriate to very short run analyses, though even then they are overly rigid. The problem with ordinary CGE models is that they are overly flexible--the basic model will allow substitution of goods (e.g., alternatives to electricity or highways) at low cost penalties. The CGE models discussed in this paper have overcome this limitation. 6 Recently, Bruneau et al. (2003; p. 3) have defined community earthquake resilience as “the ability of social units (e.g., organizations, communities) to mitigate hazards, contain the effects of disasters when they occur, and carry out recovery activities in ways that minimize social disruption and mitigate the effectors of further earthquakes.” Further, they divide resilience into three aspects, which correspond to the concepts defined above in an economic context. First is reduced failure probability, which we view as equivalent to mitigation in this paper. Second is reduced consequences from failure, which corresponds to our basic static definition of resilience. Third is reduced time to recovery, which adds a temporal dimension to our basic definition. In sum, Bruneau et al. (2003) have offered a very broad definition of resilience to cover all actions that reduce losses from hazards, including mitigation and more rapid recovery. These refer to how a community reduces the probability of structural or system failure, in the case of the former, and how quickly it returns to normal in the case of the latter. We have focused on the essence of resilience—the innate aspects of the economic system at all levels to cushion itself against losses in a given period, or reduced consequences from failure. Bruneau et al. refer to this as the robustness attribute of resilience but we emphasize that our definition is more consistent with the broader literature (see especially Klein et al., 2003). 7 Note that we are focusing on resilience on the customer side in terms of reduced consequences of infrastructure failure. Some analysts use the concept of resilience in the context of the operation of utilities, such as creating redundancies and sharing of flows between providers (see Lave et al., 2005). In the Bruneau et al. (2003) framework this refers to reducing the probability of failure. This strategy has great potential, of course, but in the context of this paper is viewed as mitigation rather than resilience. 8 The main reason for higher estimate than Tierney’s is the likelihood of under-reporting of production rescheduling, or business “recapture,” effects. 9 Note, however, the potential of resilience decreases as the disaster becomes more extensive and complex, such as the recent experience in New Orleans in the wake of Hurricane Katrina (see, e.g., Rose, 2006). 12 162 REFERENCES (ATC) Applied Technology Council. 1991. Seismic Vulnerability and Impacts of Disruptions of Utility Lifelines in the Cotermininous United States, report ATC-25. Redwood, CA: Applied Technology Council. Bruneau, M., S. Chang, R. Eguchi, G. Lee, T. O’Rourke, A. Reinhorn, M. Shinozuka, K. Tierney, W. Wallace, and D. von Winterfeldt. 2003. “A Framework to Quantitatively Assess and Enhance Seismic Resilience of Communities,” Earthquake Spectra 19: 733-52. Burns, W. P. Slovic, A. Rose, and G. Assay. 2007. “Modeling the Community Response and Economic Impacts of Risk Amplification Following a Terrorist Strike,” Proposal submitted to the National Science Foundation, Decision Research, Eugene, OR. Cho, S., P. Gordon, J. Moore II, H. Richardson, M. Shinozuka, and S. Chang. 2001. “Integrating Transportation Network and Regional Economic Models to Estimate the Costs of a Large Urban Earthquake,” Journal of Regional Science 41: 39-65. Cole, S. 1995. “Lifelines and Livelihood: A Social Accounting Matrix Approach to Calamity Preparedness,” Journal of Contingencies and Crisis Management 3: 1-11. Comfort, L. 1999. Shared Risk: Complex Seismic Response. New York: Pergamon. Corcoran, P. 2003. “IBM Business Continuity and Recovery Services,” Disaster Recovery Journal 16: 4-5. Eckles, J. 2003. “Sungard Availability Services,” Disaster Recovery Journal 16: 5-6. (FEMA) Federal Emergency Agency. 2005. 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Holling, C. 1973. “Resilience and Stability of Ecological Systems,” Annual Review of Ecology and Systematics 4: 1-23. 13 163 Klein, R., R. Nicholls, and F. Thomalla. 2003. “Resilience to Natural Hazards: How Useful is this Concept?” Environmental Hazards 5: 35-45. Lave, L., J. Apt, and G. Morgan. 2005. “Worst Case Electricity Scenarios: The Benefits and Costs of Prevention,” Carnegie Mellon Electricity Industry Center, Pittsburgh, PA. Minnesota IMPLAN Group (MIG). 2006. Impact Analysis for Planning (IMPLAN) System, Stillwater, MN. Oladosu, G. 2000. “A Non-Market Computable General Equilibrium Model for Economic Analysis and Climate Change in the Susquehanna River Basin,” Ph.D. thesis, Department of Energy, Environmental, and Mineral Economics, The Pennsylvania State University, University Park, PA. O’Rourke, T., Y. Wang, and P. Shi. 2004. “Advances in Lifeline Earthquake Engineering,” Thirteenth World Conference on Earthquake Engineering, Vancouver, Canada. Partridge, M. and D. Rickman. 1998. “Regional Computable General Equilibrium Modeling: A Survey and Critical Appraisal,” International Regional Science Review 21: 205-48. Perrings, C. 2001. “Resilience and Sustainability,” in H. Folmer, H. L. Gabel, S. Gerking, and A. Rose (eds.), Frontiers of Environmental Economics. Cheltenham, UK: Edward Elgar. Petak, W. 2002. “Earthquake Resilience through Mitigation: A System Approach,” paper presented at the International Institute for Applied Systems Analysis, Laxenburg, Austria. Pollak, R., and T. Wales. 1992. Demand System Specification and Estimation. New York Oxford: Oxford University Press. Rose, A. 1995. “Input-Output Economics and Computable General Equilibrium Models,” Structural Change and Economic Dynamics 6: 295-304. Rose, A. 2004. “Defining and Measuring Economic Resilience to Disasters,” Disaster Prevention and Management 13: 307-14. Rose, A. 2005. “Analyzing Terrorist Threats to the Economy: A Computable General Equilibrium Approach,” in P. Gordon, J. Moore and H. Richardson (eds.), Economic Costs and Consequences of a Terrorist Attack, Cheltenham, UK: Edward Elgar Publishing Company. Rose, A. 2006. “Estimating the Total Economic Impacts of Extreme Events,” DHS Center for Riak and Economic Analysis of Terrorism Events, USC, Los Angeles, CA. Rose, A. 2007a. “Macroeconomic Impacts of Catastrophic Events: The Influence of Resilience,” in J. Quigley and L. Rosenthal (eds.), Real Estate, Catastrophic Risk, and Public Policy. Berkeley, CA: University of California Press. Rose, A. 2007b. “Economic Resilience to Natural and Man-Made Disasters: Multidisciplinary Origins and Contextual Dimensions,” CREATE, USC, Los Angeles, CA. 14 164 Rose, A. and S. Y. Liao. 2005. “Modeling Regional Economic Resiliency to Earthquakes: A Computable General Equilibrium Analysis of Water Service Disruptions,” Journal of Regional Science 45: 75-112. Rose, A. and D. 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Jones (ed.), Economic Consequences of Earthquakes: Preparing for the Unexpected, Buffalo, NY: National Center for Earthquake Engineering Research. 15 165 166 Participatory Planning in Development of Comprehensive Crisis Management Plan for Water Supply Authorities Nagahisa Hirayama, Haruo Hayashi, and Sadahiko Itoh ABSTRACT It is indispensable that water supply authority staff should participate in the development of risk and crisis management plans and crisis emergency response manuals in order to increase awareness of impending crisis and develop faculties for crisis emergency response. Participatory planning in development of crisis management plan for water supply authorities is purposed in this study. For this purpose, the comprehensive risk and crisis management plan for Hanshin Water Supply Authority was developed with a participatory planning process known as the consensus workshop method. In a case study on the Hanshin Water Supply Authority, the risk and crisis management plan features a systematic structure in which a single goal is elaborated into five objectives, along with policies, actions and procedure while also taking into account the disaster management cycle. As a result, a sense of ownership should develop in participants so that they will take active roles in implementing the comprehensive countermeasures to reduce risk of multihazards. ______Nagahisa Hirayama, Research Scientist, Disaster Reduction and Human Renovation Institution, 1-5-2 Wakihamakaigan-dori, Chuo-ku, Kobe 651-0073, JAPAN Haruo Hayashi, Professor, Research Center for Disaster Reduction Systems, Disaster Prevention Research Institute, Kyoto University, Gokasyo, Uji, Kyoto 611-0011, JAPAN Sadahiko Itoh, Professor, Department of Urban Management, Graduate School of Engineering, Kyoto University, Kyoto University Cluster C, Nishikyo-ku, Kyoto 615-8540, JAPAN 167 INTRODUCTION In Japan, the Waterworks Law stipulates an emergency shut down of water supply [1]. An establishment of Business Continuity Management is required for public works: Business Continuity Guidelines 1st ed. -Reducing the Impact of Disaster and Improving Responses to Disasters published by Japanese Companies- published by Central Disaster Management Council, Cabinet Office, Government of Japan [2], and Guidelines for Business Continuity Plans created by Ministry of Economy, Trade and Industry [3]. Natural disasters frequently hit water supply facilities: the great Hanshin-Awaji Earthquake in 1995, the 2004 Mid Niigata Prefecture Earthquake, the Noto Hanto Earthquake in 2007, and Miyazaki Flood Disaster caused by typhoon No.14 in 2005. The water leakage incidents due to deterioration of water supply facilities are frequent. The risks of catastrophes have been pointed out: the Tokai Earthquake, the Tonankai Earthquake, the Nankai Earthquake, and the earthquake disaster in the Tokyo Metropolitan area. The water supply system is a lifeline upon which citizens’ lives and the economy rely on. The pressure on water supply utilities to address issues of risk and crisis management are increasing. Thus, water supply authorities should establish effective emergency response and risk and crisis management for incidents, emergencies, crises, disasters, and catastrophes. In thee process of carrying out risk and crisis management, it is necessary for stakeholders to participate in discussion. In addition, it is indispensable that the staff of water supply authorities should participate in developing risk and crisis management plans and crisis emergency response manuals in order to increase awareness of impending crisis and develop faculties for crisis emergency response. Participatory planning in developing a risk and crisis management plan for water supply authorities is purposed in this study. For this purpose, the comprehensive risk and crisis management plan for the Hanshin Water Supply Authority was developed using the consensus workshop method, a participatory planning process. This paper describes the participatory planning process of crisis management for water supply authorities, and the characteristics of the Risk and Crisis Management Plan for the Hanshin Water Supply Authority. A questionnaire survey for participants was conducted to evaluate the effect of the planning process on participants in the workshop. PARTICIPATORY PLANNING IN DEVELOPMENT OF CRISIS MANAGEMENT PLAN Crisis Management Plan Many water supply utilities have outlines, guidelines, reference books, manuals, water supply control and management plans to prepare for and manage disasters and crises. Many outlines and guidelines deal with multihazards. On the other hand, a reference books and a manuals focus on a crisis such as earthquake disaster, typhoon and flood disaster, and water quality accident. Some water supply utilities systematically prepare guidelines, manuals and reference books based on disaster prevention planning for local governments. However, these usual documents for disaster and crisis preparation share some common weakpoints. They include: • Goals of risk management were not determined; • Sense of impending crisis and achievement targets of risk and crisis management are not shared; 168 Broad/Abstract Goal Objectives Targets Policies/Strategies Programs/Projects Focused/Specific Figure 1. Structure of “strategic plan” • Many usual risk and crisis management plan are not organized in a hierarchy of means and ends; • Implementation of these plans could not complete PDCA (Plan-Do-Check-Action) Cycle. Structure of the Plan and Strategic Planning The Risk and Crisis Management Plan for the Hanshin Water Supply Authority is a “strategic plan”, which sets a goal and develops objectives, policies/strategies, programs/projects, and actions, to accomplish this goal. This is one of the distinctive characteristics of the Risk and Crisis Management Plan for the Hanshin Water Supply Authority compared to the past risk management plans of water utilities in Japan. In recent years, an action plan based on the framework of a strategic plan was required for the Central Government of Japan [4], [5]. In the field of disaster reduction and prevention, techniques of participatory planning in developing an earthquake disaster reduction plan were examined [6], [7] and [8]. Strategic planning is essential in the public sector. Strategic planning and decision processes should end with objectives and a roadmap of ways to achieve the mission, vision, and objectives [9]. The Goal, Objectives, Policies/Strategies, Programs/Projects, which gradually become more focused and specific, comprise the “strategic plan”, as indicated in Figure 1. Objectives are more specific and narrower in scope than the goal and they elaborate how the goal will be achieved. Objectives encompass Policies/Strategies to attain the identified goal. Policies/Strategies are actions that support achieving goal and objectives. Programs/Projects are specific countermeasures and implementation actions under Policies/Strategies. Thus, we introduced this structure in order to adopt the strategic plan as hierarchical structure of the risk and crisis management plan in this research. Process of Crisis Management Planning In the process of implementing crisis management, it is necessary that stakeholders, who might be affected by the plan or whose support will be needed to carry out the plan, participate in planning and building consensus; strategic management is an ongoing process in whose implementation stakeholders can become involved. Water supply utilities should introduce strategic management into preparing for disaster and crisis; they should determine their mission, vision, and goal, and then it is indispensable to approach the implementation of risk and crisis management from the viewpoint of long-term goals. 169 Risk and crisis management of water utilities would demand a new approach that water supply authority staff participate in process of developing risk and crisis management plans and crisis emergency response manuals. Therefore, according to risk assessment, analysis of the present conditions, and best practice in case studies, the Risk and Crisis Management Plan for the Hanshin Water Supply Authority, which have the framework of strategic plan, would be draw up. A approach to the Risk and Crisis Management Plan for the Hanshin Water Supply Authority has three parts which are 1) participatory planning process by the consensus workshop method, 2) assessment of the risk and the crisis emergency response, and 3) case study in measures to prepare for disaster and crisis in other water utilities and survey of best practice of measures. This approach has the following merits: • A comprehensive and coherent plan – involving stakeholders, who are various independents; • Implementation – formulating actions necessary for implementing the plan; • Increasing awareness of impending crisis among staff – participating in the process of the risk and crisis management planning; • Improvement of faculties for crisis emergency response – experience the consensus workshop method, which is an effective tool supporting consensus building and decision making; • Sense of ownership in participants – involvement in planning and willingness to take active roles in implementing the plan. RISK AND CRISIS MANAGEMENT PLANNING FOR THE HANSHIN WATER SUPPLY AUTHORITY Purpose of the Risk and Crisis Management Planning The Hanshin Water Supply Authority has been improving its guidelines for measures against disasters and crises since the 1995 Great Hanshin-Awaji Earthquake. Moreover, establishment of its manuals for crisis emergency response, it has encouraged the development of countermeasures against earthquake for water supply facilities and earthquake disaster prevention for water facilities, and preparedness for [10]. However, in recent years natural disasters, water leakage incidents, and water quality accidents are on the increase, both in frequency and scale. In order to implement disaster reduction and emergency response effectively, it is necessary for the Hanshin Water Supply Authority to expedite crisis management and to establish a comprehensive risk and crisis management plan. Thus, the program of the Risk and Crisis Management Planning for the Hanshin Water Supply Authority was carried out for 2 years starting in 2005. Figure 2 shows the outline of this project. There were three purposes of this program, stated as follows: 1. To increase awareness of impending crisis among staff; 2. To present an opportunity for brainstorming idea about risk and crisis management on their own initiative; 3. To improve the practical faculties of individuals and sections for crisis emergency response. 170 2005 Analysis of Risks and Assessment of the the situation Crises organization Case study in measures to prepare Strategic Intent for disaster and crisis in Assessment of water other water utilities supply facilities Goal and Targets 2006 Assessment of the Collection of best crisis emergency Objectives practice response Policies/Strategies Case study in the past Analysis of workflow Programs/Projects crisis emergency response The Risk and Crisis Management Plan for Hanshin Water Supply Authority Data Model Task Model Function Model Figure 2. Outline of the project of the Risk and Crisis Management Plan for the Hanshin Water Suppy Authority; Central workflow is a participatory planning with workshop method; Left flow is assessment of the risk and emergency response; Right part is survey the best practice and the past emergency response Preparedness Response Risk Crisis Management Management Recovery and Mitigation Reconstruction Figure 3. The disaster management cycle To archive these purposes, we adopted strategic plan as the hierarchy for the Risk and Crisis Management Plan for the Hanshin Water Supply Authority. This risk and crisis management plan has four features, which are 1) participatory planning with workshop method, 2) implementation of risk management with long-term goals, 3) strategic planning, and 4) coherent and comprehensive planning including disaster management cycle. As indicated in Figure 3, there are mitigation, preparedness, response, and recovery. A possible new approach is to apply participatory planning through workshop methods in risk and crisis management planning for water supply utilities; in this study, participants would consist of staff from the Hanshin Water Supply Authority. Planning Process with Workshop We designed the planning workshop so that extraction, classification, and structure of idea would be carried out based on strategic planning. Figure 4 illustrates the process of the planning workshop. 171 1st Workshop Assessment of the present situation Identification of Risk Estimation of the external factors Extraction of risk Estimation of the internal factors Identification of potential risk 2nd Workshop Risk Evaluation Risk Analysis Goal of risk and crisis management 3rd Workshop Social demands Social Targets to achieve goal Responsibility Organization and Capacity Information Facilities and Recovery and system development management Logistics reconstruction Figure 4. Process of theObjectives, workshop forPolicies/Strategies, development of the comprehensiveand Programs/Projects risk and crisis management plan 35 staff members from each sections of the Hanshin Water Supply Authority were chosen to participate in the planning workshop. Among the participants are technical staff, others are administrative officials. Participants were divided into five groups comprised of both engineers and administrative officials mixed. In this study, there were six steps in the workshop procedure: 1. Introduction of the strategic plan framework; 2. Extraction of ideas through verbalization on cards; 3. Structuring extracted ideas within the strategic plan hierarchy; 4. Sharing the structural contents with participants; 5. Evaluation of contents from the viewpoint of the strategic plan framework; 6. Building consensus among participants. In order to develop the Risk and Crisis Management Plan for the Hanshin Water Supply Authority, the planning process involved five actions which are 1) identification of crisis, 2) risk evaluation, 3) social responsibility in crisis management, 4) establishment of objectives, and 5) strategic planning; To achieve a successful conclusion to the planning workshop end, we carried out the planning process while repeatedly taking these six steps throughout the workshop. Identification of Crisis In the first workshop in December 2005, the workshop participants assessed the present situation with SWOT analysis, in which they identified internal and external factors. The participants 172 TABLE I. Identified potential threats against the Hansin Water Supply Authority Risk and Crisis Probability Magnitude Delay of crisis emergency response Medium Catastrophic Water suspension caused by natural disaster Low Catastrophic Shortage of experts and people with experience High Moderate Water transmission trouble by disaster Low Catastrophic Shortage of distributed amount by disaster Low Catastrophic Crisis due to deterioration of facilities High Moderate Accidental water resource pollution Medium Catastrophic Unavailable water resource by man-made hazards Medium Catastrophic Financial crisis due to budget squeeze High Moderate Business discontinuance caused by power failure Low Catastrophic Deficiency measures due to lack of finances High Moderate identified the importance of each of the internal and external factors in each group, and five external factors and five internal factors were extracted. Using the matrix of internal and external factors, the identification of potential risks and crises for the Hanshin Water Supply Authority was carried out in each workshop groups. The next step was to share the identified crises with all workshop participants. Then 20 potential risks and crises, which the Hanshin Water Supply Authority should take any and all steps to overcome, were identified. An example of the identification of potential threats is shown in TABLE I. Risk Evaluation The second action was to evaluate the identified risks and crises. First, the likelihood that the identified crisis would occur was estimated in each workshop groups. This estimate would be expressed in an occurrence over time, for example once every ten years. In turn, these estimates could be grouped and expressed on a grading scale as ‘high’, ‘medium’ or ‘low’ risk. Efforts were made to ensure that estimates were accurate and based on available and objective information from experts and professionals who participated as workshop table manager in the planning workshop. Secondly, the impact or magnitude of damage associated with each crisis was evaluated in each workshop groups. A rating scale was developed that reflected the organization’s view of the magnitude of risk, from the catastrophic to the insignificant. The scores for both probability and magnitude could be combined and displayed on a risk matrix. All participants in the planning workshop shared risk matrices with other workshop groups. Then, with the consensus of participants, a result of evaluation of the identified crises in the Hanshin Water Supply Authority was displayed on a risk matrix. The result of the risk evaluation is shown in Figure 5. It is indicated that the Hanshin Water Supply Authority would have two different crises. One crisis that score in the bottom right cell or middle right cell would be a rare or likely event with 173 Magnitude Insignificant Moderate Catastrophic Financial Crisis Insufficiency of High expert Deterioration of facilities Medium Man-made Hazards Probability Natural Low Disaster Figure 5. Risk evaluation on a risk matrix potentially catastrophic results. Among possible crises are natural disasters and man-made hazards. In order to overcome such a crisis, it is necessary to carry out Business Continuity Management that should aim to provide continuity in customer service at a minimum acceptable level. On the other hand, another crisis, that has been rated as ‘high’ in the top middle of the matrix, would be a event that is almost certain to occur, but is considered moderate in its impact. These are financial crises, insufficiency of experts and people with experience, and deterioration of water supply facilities. The reduction of these risks and crises would require implementation of business strategies and asset management. Social Responsibility of the Hanshin Water Supply Authority In the third workshop in March 2006, each group discussed the social responsibility of the Hanshin Water Supply Authority. After sharing the discussion with all workshop participants, a goal of the strategic crisis management for the Hanshin Water Supply Authority was established. As a result, the goal is “to supply secure and reliable water in any crisis emergency”. Establishment of Objectives In the fourth action, objectives of the risk and crisis management plan were established. First, the workshop participants furnished ideas about what they should do what to achieve the goal of the Hanshin Water Supply Authority crisis management plan. Using the affinity diagram method, 218 pieces of idea cards were structured according to the framework of the strategic plan. As a result, these idea cards could be classified into six categories which were 1) preparation of the emergency response manual, 2) organization and system, 3) capacity development, 4) information management, 5) water supply facilities and logistics, 6) recovery and reconstruction. Preparation of the emergency response manual is an important stage of the crisis management process and one way of the implementing the risk and crisis management plan. Therefore, in the Risk and Crisis Management Plan for the Hanshin Water Supply Authority, we set five objectives in the classified categories with the exception of `preparation of the emergency response manual` category to attain the identified goal. The framework of the risk and crisis management plan was illustrated in 174 Goal To supply secure and reliable water in any crisis emergency Objectives Social Responsibility, Objectives, and Targets Targets Organization Capacity Information Facilities and Recovery and and system development management logistics Reconstruction To establish To clarify To develop teaching Policies organization for responsibility on materials and tools sharing information emergency for education Information sharing in Arrangement of staffs Incident commander documents To collect the past Actions Information sharing in Analysis of emergency incidents and sections tasks and procedures experience cooperation between To clarify responsibility technical staffs and of sections on administrative officials emergency Figure 6. Framework of the Risk and Crisis Management Plan for Hanshin Water Supply Authority Figure 6. Actually, the idea cards grouped into five categories other than `preparation of the emergency response manual` were structured according to strategic plan hierarchy and classified into the content levels as ‘Objectives’, ‘Policies/Strategies’, and ‘Programs/Projects’. Then, the ‘Objectives’ idea cards were organized and elaborated into a complete sentence. Strategic Planning To accomplish the goal of this project, the Risk and Crisis Management Plan for the Hanshin Water Supply Authority was developed and systematically structured according to a hierarchy of means and ends using the workshop method. Participants were divided into five workshop groups that one workshop group would deal with one classified category such as ‘organization and system’, ‘information management’. In order to increase the effectiveness of the crisis management plan and clarify the roles and responsibilities, ‘the person and the section of charge’ and ‘period of time of actions’ were decided. In this plan, ‘duration of action’ was expressed on a scale as ‘long-term’, ‘medium-term’, or ‘short-term’ action. For example, a ‘short-term’ program is an action to be achieved in three years. Implementation of the plan According to the above, the comprehensive Risk and Crisis Management Plan for the Hanshin Water Supply Authority was developed with a participatory planning process using the consensus workshop method. In the future, mitigating and reducing the impact of crisis on the Hanshin Water Supply Authority requires the implementation of this risk and crisis management plan. Therefore, it 175 is important to push forward the arrangement and documentation of the crisis emergency response manual and to drive the completion of the PDCA cycle in crisis management by using contingency simulations, training, and education. To accomplish the goal of the risk and crisis management plan, that is to supply secure and reliable water in any crisis emergency, it is necessary to promote the reinforcement of preparation and mitigation of risk in cooperation with stakeholders including customers and concerned organizations. ANALYSIS OF EFFECT OF PARTICIPATORY PLANNING In this section, we evaluate the effect of the planning process on participants in the workshop. Figure 7 shows the look of the workshop that participants were encouraging creative thinking. A questionnaire survey for participants in the workshop was conducted in May 2007 after the project of developing the risk and crisis management planning. In this survey, a survey sheet was composed of Figure 7. Look of the workshop that participants were encouraging creative thinking Figure 8. Changes of crisis imagination before and after the participation 176 Figure 9. Sense of ownership of the crisis management three parts: ‘How much do you feel that a difference of risk perceptions with before and after participation in this planning?’; ‘How concerned do you feel about the risk and crisis management plan?’; ‘How interested are you in the consensus workshop method?’ Each questions was answered on a five-rating scale. 32 participants returned completed data, yielding an overall response ratio of 91.4%. Figure 8 shows the changes of crisis imagination before and after the participation. More than 60% participants likely appreciate their own capacity development of the crisis imagination and the supposition of crisis emergency response. This result clearly validates participatory in the planning workshop for development of the risk and crisis management plan is effective for improving their crisis imagination capacity. Also, Figure 9 shows a sense of ownership of the crisis management. Most of participants probably recognize the awareness of ownership of the risk and crisis management. This result indicates that a sense of ownership should develop in participants so that they will take active roles in implementing the comprehensive countermeasures to prepare and mitigate the risk of multi hazards. CONCLUSION This study attempts to develop a participatory planning in development of comprehensive risk and crisis management plan for water supply authorities. For this purpose, the Risk and Crisis Management Plan for the Hanshin Water Supply Authority was developed using a participatory planning process. In the Hanshin Water Supply Authority case study, the risk and crisis management plan features a systematic structure in which a single goal is elaborated into five objectives, along with policies, actions and procedures while also taking into account the disaster management cycle. It is our belief that in comparison with other risk and crisis management plans in Japan, this Risk and Crisis Management Plan is one of the most comprehensive crisis management plans ever compiled. In addition, a questionnaire survey for participants was conducted to evaluate the effect of the 177 planning process on participants in the workshop. Hence, it is concluded that a participatory planning in development of crisis management plan should create a sense of ownership in participants so that they will take active roles in implementing the comprehensive countermeasures to reduce risk of multihazards. ACKNOWLEDGMENTS In this study, the Hanshin Water Supply Authority staff actively participated in the planning workshop. This risk and crisis management planning project was managed by Kenichi Kobayashi, Kenji Komiyama, Masakazu Mihara, and Tomohisa Okamoto of Hanshin Water Supply Authority. The planning workshop was conducted by Head Researcher Kenji Koshiyama, Chief Researcher Kenji Harada, Chief Researcher Kiyomine Terumoto, Chief Researcher Shinya Kondo, Research Fellow Kunihiro Fukutome, Research Fellow Makoto Yasutomi, and Research Fellow Shingo Nagamatsu of Disaster Reduction and Human Renovation Institution, Masayuki Mori, Yukihito Nakagawa, and Hiromi Takeishi of Nihon Suido Consultants Co., Ltd. serving as workshop table managers. The support provided by all stakeholders of the Risk and Crisis Management Planning for the Hanshin Water Supply Authority is gratefully acknowledged. REFERENCES [1] A Society for the Study of Waterworks Law. 2003. “Explanation the Waterworks Law Article by Article,” Japan Water Works Association. [2] Cabinet Office, Government of Japan. 2005. “Business Continuity Guidelines 1st ed. -Reducing the Impact of Disaster and Improving Responses to Disasters published by Japanese Companies-,” Central Disaster Management Council. [3] Ministry of Economy, Trade and Industry. 2005. “Guidelines for Business Continuity Plans,” Research Institute of Economy, Trade and Industry. [4] Center for Accountability and Performance, American Society for Public Administration. 2001. “Performance Measurement Concepts and Techniques,” edited by S. Ueyama, Tokyo Horei Publishing Co. Ltd. [5] Norio Maki. 2006. “Development of Disaster Prevention Plan based on Strategic Planning,” Disaster Reduction Management, 1: 40-43. [6] K. Tamura, H. Hayashi, S. Tatsuki, N. Maki, S. Tanaka, T. Kondo, K. Horie, M. Banba, Y. Karatani, K. Hasegawa, and Y. Fukasawa. 2004. “Development of Participatory Strategic Planning in the Process of Disaster Reduction Planning: A Case Study in Marikina City, Philippines,” Journal of Social Safety Science, Institute of Social Safety Science, (6): 129-138. [7] N. Maki, T. Kondo, K. Tamura, H. Hayashi, K. Topping, S. Tatsuki, K. Hasegawa, K. Horie, M. Banba, S. Tanaka, Y. Fukasawa, and N. Yoshitomi. 2004. “A Comprehensive Earthquake Disaster Reduction Planning with Stakeholders; Development of Marikina Comprehensive Earthquake Disaster Reduction Program(CEDR) and Action Plan,” Journal of Social Safety Science, Institute of Social Safety Science, (6): 111-120. [8] N. Maki, H. Hayashi, and K. Tamura. 2006. “Action Plans for Disaster Reduction Based on Strategic Planning Framework; Contents and Planning Process of Disaster Reduction Plans in Prefecture Governments,” Journal of Social Safety Science, Institute of Social Safety Science, (8): 197-206. [9] Yoshiaki Ryu and Ryo Sasaki. 2002. “Practical Guide to Strategy Formulation and Management for Public and Not-for-profit Organizations,” Taga Publishing Co. Ltd., pp.53-60. [10] Tomohisa Okamoto, Kenichi Kobayashi, Kenji Komiyama, and Masakazu Mihara. 2006. “Program for Risk and Crisis Management on Hanshin Water Supply Authority,” Proceedings of 50th Annual Conference on Kansai Branch JWWA, pp.176-178. 178 SEISMIC ASPECTS OF THE SFPUC WATER SYSTEM IMPROVEMENT PROGRAM Luke Cheng1, Brian Sadden2 ABSTRACT The San Francisco Public Utilities Commission (SFPUC) manages a complex water supply system stretching from the Sierra to the City and featuring a complex series of reservoirs, tunnels, pipelines, and treatment systems. Many of the critical facilities are in a highly seismic active area underlain by three active faults: San Andreas, Hayward and Calaveras faults. A recent USGS study also indicates that there is a probability of 62% for one of major earthquakes in the area. In 2002, the SFPUC, together with its 28 wholesale customers launched a $4.3 billion Water System Improvement Program to repair, replace, and seismically upgrade the system’s aging pipelines, tunnels, reservoirs, pump stations, storage tanks, and dams. This paper discusses the seismic aspects of the program including level of service objectives after a major earthquake, system reliability before and after the program is completed, and major seismic projects in San Francisco City, San Francisco Peninsula, San Francisco Bay Division and Sunol Valley regions. INTRODUCTION The San Francisco Public Utilities Commission (SFPUC) has started one of the largest water system improvement programs ($4.3 billions) in the United States since 2002. The primary driving forces behind the program are the high seismic vulnerability and the old age (almost 100 years old) of the San Francisco water system. The objective of the program is to improve the water supply, the water quality, and the San Francisco water system’s seismic resistance capability. The paper covers mainly the seismic aspect of the program, and the following topics are discussed. • An overview of the San Francisco water system • Level of service goals that SFPUC would like to achieve after the program is completed • A brief discussion on the system reliability studies performed for the system with and without the seismic upgrade program • Descriptions of some of major seismic retrofit projects in the program 1 Manager, Structural Section, Engineering Management Bureau, San Francisco Public Utilities Commission, 1155 Market St. 7th Floor, San Francisco, California, USA 94103 2 Bureau Manager, Engineering Management Bureau, San Francisco Public Utilities Commission, 1155 Market St. 7th Floor, San Francisco, California, USA 94103 179 SAN FRACISCO WATER SYSTEM OVERVIEW The SFPUC manages a complex water supply system that is geographically bounded between Hetch Hetchy Valley in Yosemite National Park and the San Francisco Bay Area. The distribution system is driven wholly by gravity except where local watershed- treated waters are introduced. The system provides high quality water to the City and County of San Francisco as well as southern regions of the Bay Area. The SFPUC provides water to 2.4 million residential, commercial, and industrial consumers in the San Francisco Bay Area through direct retail deliveries to San Francisco customers and through wholesale deliveries to 28 suburban customers (Figure 1). Approximately two-thirds of the delivered water is supplied to suburban agencies in the counties of Alameda, Santa Clara, and San Mateo, and close to one-third is used by customers in the City of San Francisco. Figure 2 provides a view of the SFPUC system from Hetch Hetchy Valley to the City of San Francisco. Figure 1 – SFPUC Water System Retail Customers Figure 2 – SFPUC Water System 180 Water for the system is supplied from two primary sources: 1) Upper Tuolumne River Watershed; and, 2) Local surface water from the East Bay and Peninsula watersheds. The regional water system delivers an annual average of approximately 260 million gallons of water per day to a population of 2.4 million water users. The regional system consists of over 280 miles of pipelines, over 60 miles of tunnels, 11 reservoirs, 5 pump stations, and 2 water treatment plants. The City Distribution System (local system) consists of a network of more than 1,250 miles of pipeline within the City, 12 reservoirs, 9 storage tanks, 12 pumping stations, 8 hydropneumatic stations, and 17 chlorination stations. The SFPUC regional water supply system consists of five major regions: • The Up-country Facilities – from Hetch Hetchy Reservoir to Alameda East Portal; • Sunol Valley Region – from Alameda East Portal to Irvington Portal; • Bay Division Pipelines – from Irvington Portal to west side of the San Francisco Bay; • Peninsula Region – from Bay Division Pipelines to City of San Francisco; and, • San Francisco Regional Facilities – various locations in the City of San Francisco. LEVEL OF SERVICE OBJECTIVE The vulnerability of the system to a major seismic event is well known. An USGS study states that there is a 62% probability for one or more magnitude 6.7 or greater earthquakes in the San Francisco Bay from 2003 to 2032. They are the prime drivers for the placement of the system upgrade responsibilities on SFPUC by the California legislatures. During the early stage of the program, desired Level of Service (LOS) objectives after earthquake were established and approved by the SFPUC Commission. LOS objectives are divided into three categories: (1) delivery after a major earthquake, (2) percent of turnouts that receive water, and (3) post-earthquake recovery. The major earthquakes are defined as M7.9 or larger for the San Andreas Fault event, M7.2 or larger for the Hayward Fault event and M6.8 or larger for the Calaveras fault event. Delivery After a Major Earthquake The LOS objective for delivery after a major earthquake is stated as: “Deliver basic service to all customer groups within 24 hours, equivalent to 96, 37, and 82 MGD delivery to the Santa Clara/Alameda/South San Mateo County, the Northern San Mateo County, and City of San Francisco customer groups, respectively.” This objective provides basic service, defined as winter-time delivery, to each customer group after an earthquake. The winter flow is 215 MGD to the Santa Clara/Alameda/South San Mateo County, the Northern San Mateo County, and City of San Francisco customer groups. Up to 24 hours may be required after the earthquake to isolate damaged facilities, such as leaking pipelines, from the system and to ramp up supply from sources that are operational. 181 There is a level of uncertainty associated with the impacts of earthquakes, such as the level of shaking, site-specific conditions, and exact locations where pipeline breaks may occur. Therefore, there is always the possibility that the damage to the system and the delivery that can be achieved may be more or less than estimated. There is a 10 percent probability that deliveries will be less than estimated. Percent of Turnouts That Receive Water The LOS objective for percent of turnouts that receive water after a major earthquake is stated as: “Deliver basic service to at least 70% of turnouts within each customer group, to improve uniformity of reliability across a customer group.” This objective provides basic service to at least 70% of the turnouts within each customer group after an earthquake. This objective helps to improve seismic reliability over the entire customer group, and reduces the possibility of cases in which the seismic delivery quantity objective is met, but delivery of all of the water is only to a small percentage of turnouts. Because there is a level of uncertainty associated with the impacts of Earthquakes as stated in the previous section, there is always the possibility that the damage to the system and the delivery that can be achieved may be more or less than estimated. There is a 10 percent probability that percentage of turnouts that receive water will be less than estimated. Post-Earthquake Recovery The LOS objective for post-earthquake recovery is stated as: “Make temporary repairs to restore delivery of 300 MGD (average day demand) to each customer group within 30 days, assuming resources and infrastructure are available.” This objective provides average day demand 30 days after a major earthquake. Temporary repairs to facilities would be made to achieve this objective, assuming resources, repair materials and access are available. Permanent repairs to facilities would take longer to complete. For all seismic reliability LOS objectives, delivery is evaluated on a customer group basis, and delivery to individual turnouts within a customer group may vary. There is inherent uncertainty associated with the potential impacts of seismic events, including the uncertain nature of the seismic hazard, seismic response of facilities, and less likely but potentially catastrophic damage scenarios. Damage to other critical lifelines beyond the control of the SFPUC, such as roads and bridges, may also impact the ability to access and repair facilities after an earthquake. 182 SYSTEM RELIABILITY The reliability of the Regional Water System is analyzed using a System Reliability Model. This model is specific to the SFPUC’s system, and includes all of its major pipelines, treatment plants, pump stations, valve lots, and dam/reservoirs. The System Reliability Model determines system reliability by combining the probabilities of failure of individual facilities using the Monte Carlo method. The model itself is a complex set of spreadsheet modules that utilize input from the system hydraulic model. The Monte Carlo method is a statistical method of analyzing the behavior of complex physical or mathematical systems. It involves the use of statistical sampling techniques to obtain approximate solutions in terms of a range of values each of which has a probability of occurring. The capabilities of this method make it ideal for evaluating the SFPUC system in that it captures key factors such as: • Individual facility vulnerability • Systemic reliability and redundancy • Seismic reliability The Monte Carlo method was designed to aggregate probability data for complex systems with large numbers of components. Isoyama and T. Katayama developed this method to evaluate the seismic performance of large Japanese water supply systems over 20 years ago. In particular, they examined the performance of the Tokyo Water Supply System. The system reliability model is a statistical tool intended to provide a quantitative estimation of reliability and risk of the system. It cannot predict the response of the system after an earthquake. The model is intended for planning-level analysis and utilizes regional/screening-level hazard and vulnerability data. The process is comprised of 4 key components: • Model Input Data: Probability of failure of pipelines and facilities • Generation of Multiple Outage Scenarios (Monte Carlo Simulation) • Calculation of System Delivery Capability • Generation of Model Output in the Form of Reliability Curves (Delivery Capability & Probability) The results of the System Reliability Model analysis are described in the following sections. Post-Earthquake Delivery 24 Hours after a Major Earthquake The post-earthquake delivery analysis evaluates how much water the system can deliver after a major San Andreas, Hayward, and Calaveras earthquake, and the percentage of turnouts that receive that water. 183 Figure 3 shows how much water the system can deliver, in MGD, to South Bay, Peninsula, and City of San Francisco customer groups after a major San Andreas, Hayward, and Calaveras earthquake. The blue bars show the performance of the existing system and the red bars show the improvement provided by the WSIP. The yellow bars represent basic service, which is the LOS objective. Figure 3 –Delivery 24 Hours After a Major Earthquake Figure 4 shows the percentage of turnouts within each customer group that receive at least basic service following a major San Andreas, Hayward, and Calaveras earthquake. The blue bars show the performance of the existing system, the red bars show the improvement provided by the WSIP. The yellow bars represent 70 percent of turnouts, which is the LOS objective. Figure 4 – Percent of Turnouts hat Receive Water 24 Hours After a Major Earthquake 184 As discussed before, seismic hazards and levels of facility damage from earthquakes have an inherent uncertainty and cannot be “predicted” in an exact manner. The estimated values in Figures 3 and 4 have a probability of 10 percent chance that the actual delivery or percentage of turnouts that receive after an earthquake will be less than shown. Post-Earthquake Recovery 30 Days after a Major Earthquake The post-earthquake recovery analysis evaluates how much water the Regional Water System will be able to deliver 30 days after a major San Andreas, Hayward, and Calaveras event. The estimated delivery reflects the ability of the system to recover after an earthquake when temporary repairs are made in the first 30 days. A two-step process was used to determine the recovery capability of the system. The first step involved developing a facility outage scenario for a San Andreas, Calaveras, and Hayward earthquake. The outage scenarios were based on the assumption that facilities with a probability of failure greater than 25% would be out of service after these earthquakes occur. In the second step, estimated repair times were used as a basis to determine how many of the damaged facilities could be brought back to service after 30 days, assuming that resources are available and facilities are accessible. The repair times for facilities were based on repair times in the Emergency Response and Recovery Plan (ERRP) with additional input from SFPUC Operations. The delivery capability of the system was then estimated based on the facilities that could be returned to service in 30 days. Figure 5 shows the post-earthquake delivery for the system after 30 days. Figure 5 - Post-Earthquake Recovery: Delivery 30 Days After a Major Earthquake 185 SEISMIC PROJECTS In order to meet the level of service as defined in previous sections, several of the SFPUC facilities need to be seismically upgraded to the present code standard. The following is a brief description of some of the major seismic projects, grouped by region: Sunol Valley Projects Calaveras Dam Replacement Calaveras Reservoir is the largest local reservoir in the Regional Water System. The Calaveras Dam as originally designed allows for retention of 96,850 acre-feet of local runoff in Alameda County. Because the dam is located in a seismically active fault zone and was determined to be seismically vulnerable, the California Department of Water Resources Division of Safety of Dams (DSOD) has limited the reservoir to a maximum level corresponding to 31,000 acre-feet. A new dam will be rebuilt immediately downstream of the existing dam to restore the reservoir’s historic capacity. The project will provide for planning, design and construction of a replacement dam that can be expanded in the future. It will include new or rehabilitated outlet works (for seismic safety, improved operations and maintenance, and to facilitate releases for fish). A second pipeline from the new dam to Sunol Valley Water Treatment Plant (SVWTP) will also be included to provide the additional 70 million gallons per day (mgd) of capacity needed to supply the full SVWTP treatment capacity from Calaveras Reservoir. Irvington Tunnel The Irvington Tunnel is essentially a continuation of the Coast Range Tunnel. At its eastern end the tunnel connects to the Alameda Siphons and at its western end connects to the Bay Division Pipelines at Irvington Portal. The Irvington Tunnel and Alameda Siphons carry water from two of the three SFPUC sources, Hetch Hetchy and SVWTP. These facilities have been determined to be seismically vulnerable, and because all water to 2.5 million people pass through them, they cannot be shut down for inspection and maintenance. This project is to construct a new tunnel parallel to, and just south of, the existing Irvington Tunnel to convey water from the Hetch Hetchy system and the SVWTP to the Bay Area. The new tunnel will be a redundant water transmission facility to the existing Irvington Tunnel to ensure continued delivery of water after a seismic event and to allow preventive maintenance of the existing tunnel. This project also improves delivery by allowing existing facilities to be taken out of service for maintenance while continuing to meet demands and replenish Crystal Springs Reservoir. Bay Division Projects Seismic Upgrade of Bay Division Pipelines (BDPLs) at Hayward Fault 186 This project will provide for planning, design and construction of shutoff and crossover facilities on both sides of the Hayward fault, and seismically improved sections of pipe between the two shut-off and crossover facilities. This project will result in a seismic resistant design for BDPL Nos. 3 and 4 where they cross the Hayward Fault. This is a particularly difficult project to construct in that the fault traces are under a major freeway intersection. Bay Division Pipeline Reliability The BDPLs (four pipelines that were built in 1925, 1936, 1952, and 1973) transport water from the Irvington Tunnel Portal to users in the East Bay, South Bay and Peninsula systems as well as supplement the supply in the Crystal Springs and San Andreas Reservoirs. This project consists of constructing a 21-mile Bay Division Pipeline No. 5 (BDPL No. 5) from Irvington Tunnel Portal in Fremont to Pulgas Tunnel Portal near Redwood City, including a tunnel under San Francisco Bay and adjacent marshlands. This project improves seismic reliability of BDPLs across San Francisco Bay after a major earthquake. It also improves delivery reliability by allowing existing facilities to be taken out of service for maintenance while continuing to meet day-to-day demands and replenish Crystal Springs Reservoir. Bay Division Pipeline (BDPL) No. 4 Slip Lining Prestressed Concrete Cylinder Pipe (PCCP) Sections Based on preliminary condition assessment and evaluation of rehabilitation needs of the Bay Division Pipelines, it was determined that rehabilitation of PCCP sections of BDPL No. 4 have to be rehabilitated to meet the system performance standards. This project will be for slip lining reaches of BDPL No. 4 that are constructed of PCCP: from Irvington Tunnel to Calaveras Valve Lot and from Stanford Tunnel West Portal to Pulgas Portal. The slip lining will improve seismic performance and improve delivery reliability of BDPL No. 4 and the entire Bay Division Pipeline system. Peninsula Projects Baden and San Pedro Valve Lot Seismic Evaluation & Upgrade Baden and San Pedro Valve Lots are critical points in the Regional Water System. All the Peninsula Pipelines run through Baden Valve Lot and all of the Peninsula High Zone pipelines pass through the San Pedro Valve Lot. Disruption of flow at these valve lots in an earthquake would isolate Peninsula and San Francisco customers from all three of the SFPUC’s water sources; therefore, it is critical that these facilities remain operational after a major seismic event. The valves, vaults, and piping at these facilities will be evaluated and upgraded for seismic reliability. This project provides for construction of the upgrades to ensure the reliability of deliveries to Peninsula and San Francisco customers following a major earthquake. 187 Capuchino Valve Lot Capacity Improvements This project provides for upgrade of a pressure-reducing station, which will allow flow from a high-pressure pipeline to supply a low-pressure pipeline. This project increases seismic reliability by improving capacity to deliver HTWTP water to City, Peninsula, and South Bay customers after a major earthquake that may result in the loss of East Bay and Hetch Hetchy water supplies. It also improves delivery reliability by continuing to meet day-to-day demands to Peninsula and South Bay customers in the event of planned maintenance or unplanned outages that may result in the loss of East Bay or Hetch Hetchy supplies. Crystal Springs Pump Station and Crystal Springs-San Andreas Pipeline (CSPS and CS-SA PL) Components of the system that moves water from Crystal Springs Reservoir to the Harry Tracy Water Treatment Plant were constructed at various stages form the late 1800s to 1968. The components include the Crystal Springs Outlet facilities, Crystal Springs Pump Station, Crystal Springs-San Andreas Pipeline, and Outlet Facilities from San Andreas Reservoir to the Harry Tracy Water Treatment Plant (HTWTP). These facilities are to be evaluated and upgraded. This project is to provide for seismic improvements of facilities that convey water from Crystal Springs Reservoir to HTWTP. This project would also increase the transmission capacity of raw water from Crystal Springs Reservoir to San Andreas Reservoir in order to reliably supply 140 mgd of raw water for treatment at HTWTP – a necessary operating situation after a major seismic event with the resulting failures in the main system. Crystal Springs Bypass Tunnel No. 2 The existing Crystal Springs Bypass Pipeline (CSBP) is a critical line between Hetch Hetchy supply and the Peninsula, and is the only pipeline carrying water north from the Crystal Springs Balancing Reservoir. The CSBP is a 96-inch diameter prestressed concrete cylinder pipe (PCCP) that was installed in 1969 below a hillside along Polhemus Road in the City of San Mateo. Currently, the CSBP cannot be shut down for an extended period of time for inspection or maintenance due to its role in supplying water to the Peninsula. This project provides for construction of a 4500 –foot long, 9 feet diameter tunnel to provide redundancy to the CSBP and improve delivery reliability. Harry Tracy Water Treatment Plant (HTWTP) Improvements HTWTP was constructed in 1971 and subsequently expanded in 1988 and 1990 to a maximum capacity of 160 mgd, although initially it was designed and approved for a maximum capacity of 180 mgd. This project provides for seismic retrofit and rehabilitation of the building/facility, including upgrade of the ozone system, process piping and other related equipment. At the completion of this project, the plant will have a sustainable operating capacity of 140 mgd. This is necessary for delivery reliability such that the treatment plant can deliver water from local reservoirs (San Andreas, 188 Crystal Springs) to the Peninsula and San Francisco if Hetch Hetchy and/or Sunol water is unavailable. San Francisco Regional Projects Crystal Springs Pipeline (CSPL) No. 2 & San Andreas Pipeline (SAPL) No. 3 These projects provide for repair and replacement of sections of Crystal Springs and San Andreas pipelines. The seismic improvements to the pipelines provided by these projects are needed to meet the seismic reliability levels of service goals and providing redundancy to high zone customers along the Peninsula and in San Francisco. Sunset Reservoir – North Basin Sunset Reservoir is one of three terminal reservoirs in the Regional Water System that is located in San Francisco. The reservoir was constructed in 1938 and is seismically vulnerable. This project provides for seismic upgrade of the reservoir roof on the north basin of Sunset Reservoir and strengthening of the reservoir’s roof, columns and beams. In addition, it provides for surrounding site stabilization and water quality improvements for sampling and disinfection. University Mound Reservoir Upgrade The North Basin of the University Mound Reservoir was constructed in 1885 and reconstructed in 1924. The reservoir is the terminus of the “low zone” water in the SFPUC’s City Distribution Division, and is seismically vulnerable. This project provides for seismic upgrades to one of the two largest treated water storage reservoirs to meet the California Division of Safety of Dams requirements. The project will also provide water quality improvements to facilitate continued compliance with state and federal regulations. Various Locations Standby Power Facilities Various Locations This project provides for standby power at various facilities to keep them operating during power outages, thereby reducing the potential for interruption of supply to customers. The locations identified in the needs assessment include the following facilities: San Pedro Valve Lot, Capuchino Valve Lot, Millbrae facility, San Antonio Reservoir and Turner Dam, Alameda West, HTWTP and Calaveras Reservoir. Pipeline Repair Readiness This project will improve seismic reliability by implementing planning efforts to improve the SFPUC’s readiness to respond to pipeline failures following an earthquake. A pipeline repair plan will be developed, with a list of potential areas of vulnerability 189 (possible locations of pipe breaks or leaks), equipment and personnel needed to effect the repairs. As part of readiness improvement, SFPUC will investigate contracting options to allow for quicker delivery of materials and quicker repair, in order to reduce costs of potentially stockpiling all needed material and equipment. CONCLUSIONS SFPUC is embarking on a mega-water supply improvement program. The seismic component of the program is a major task to insure that the system can meet the system’s delivery goals after a major earthquake in the San Francisco Bay Area. The delivery goals consist of three parts: (1) deliver winter day demand of 215 MGD to the customers, and deliver basic service to at least 70% of the turnouts 24 hours after a major earthquake; and (2) make repairs to ensure delivery of average day demand of 300 MGD 30 days after the major earthquake. A system reliability study was done to evaluate how much water the system can deliver and what percentage of turnouts will receive water after a major San Andreas, Hayward, and Calaveras earthquake. The study shows significant improvements for the system with the program’s implementation. In order to achieve the desired improvement, several projects in the Sunol Valley, the Bay Division, the Peninsula and the San Francisco regions were identified and are under planning, design, or construction. In addition, standby power facilities at various locations were added to reduce the potential for supply interruption, and a pipeline repair plan was developed to improve the SFPUC’s response to pipeline failures after an earthquake. REFERENCES Working Group on California Earthquake Probabilities (2003), “Earthquake Probabilities in the San Francisco Region: 2002-2031”, USGS Open-file Report 03-214, U. S. Geological Survey Isoyama, R. and Katayama, T. (1982), “Reliability Evaluation Method of Large-Scale Water Supply Net Works During Seismic Disaster”, Proc. of JSCE, No 32, pp. 37-48 (in Japanese); and Transactions of JSCE, Vol. 14, 1982, pp.422-423 (in English) 190 Information Provision to Residents on Construction of Regulating Reservoir at Landslide Site Caused by Earthquake Shinji Nakayasu, Masao Kadowaki, and Toshiaki Hashimoto ABSTRACT Hanshin Water Supply Authority (HWSA) planned construction of a regulating reservoir at a landslide-devastated site. In this case, the residents near the construction site had a heightened sense of concern for the earthquake protection of the reservoir. Therefore HWSA considered the seismic design of the reservoir and also the prevention of a second disaster in the neighboring residential area. In order to further reassure the residents, it was necessary to inform the residents about the measures taken. In this paper, the measures at each construction process in communicating with the residents are presented as follows: • Design phase: Earthquake effect assessment and measures taking into account social and natural environment • Construction phase: Verification of the effect of the measures and proper execution of the construction • Completion and after (maintenance): Monitoring the stability of the effect of the measures ______Shinji Nakayasu, Waterworks Engineer, Construction division, Hanshin Water Supply Authority, 3-20-1 Nishiokamoto, Higashinada, Kobe, Hyogo, Japan 658-0073 Masao kadowaki, Waterworks Engineer, Construction division, Hanshin Water Supply Authority, 3-20-1 Nishiokamoto, Higashinada, Kobe, Hyogo, Japan 658-0073 Toshiaki Hashimoto, Waterworks Engineer, Construction division, Hanshin Water Supply Authority, 3-20-1 Nishiokamoto, Higashinada, Kobe, Hyogo, Japan 658-0073 191 1. Introduction The Hanshin Water Supply Authority (HWSA) is a municipal utility that supplies drinking water to 2.4 million consumers living in the 719 km2 Hanshin area, southern Hyogo Prefecture, and has a capacity of 1,128,000 m3/day and a pipeline length of 186 km (Fig. 1). The Great Hanshin-Awaji Earthquake that occurred in 1995 devastated a major portion of the Hanshin area. Our waterworks facilities also suffered severe damage mainly to the aged pipelines and structures, and therefore, sufficient water could not be supplied immediately after the earthquake [1]. Learning from this experience, we are now improving the seismic capacity of existing facilities and establishing a backup system on the basis of the “Seismic Capacity Improvement of Facilities plan” that was formulated after the disaster [2]. In this paper, as part of the plan, we report the efficacy of the provision of information on earthquake disaster countermeasures to gain the understanding of the local residents, who have earthquake disaster experience, regarding the construction of a regulating reservoir (Kabutoyama regulating reservoir) to improve the water supply stability. Figure 1. Arrangement of facilities of Hanshin Water Supply Authority. 2. Outline of Kabutoyama Regulating Reservoir Kabutoyama regulating reservoir is a pure water subterranean regulating reservoir with a reinforced concrete structure and an effective capacity of 80,000 m3. It is located at the base of Kabuto Mountain (Kabutoyama-cho, Nishinomiya City), which is at the eastern end of the Rokko Mountain Range. This was the site of a water treatment plant that was shut down in 2001. 192 This site is the starting point of a transmission tunnel and has good geographical conditions for transporting water by gravity flow (Fig. 2 and 3). After the completion of this regulating reservoir, an approximately 1.5-fold increase in the capacity of the pure water reservoir managed by HWSA has been obtained. Figure 2. Aerial view of Kabutoyama regulating reservoir (May 2007). Figure 3. Plan view and cross section of Kabutoyama regulating reservoir. 193 3. Disaster Damage at Construction Site and Residents’ Feeling concerning Construction of Regulating Reservoir 3.1 Landslide disaster The construction site is located next to a quiet residential area within an educational district, which is distinguished by several universities. During the Great Hanshin-Awaji Earthquake, a large-scale landslide occurred around this site. This landslide first occurred on the lower slopes at the eastern end of the site, and slope surface soils, as well as a part of the pure water treatment plant, swept through part of residential area below, causing 34 casualties. The surface soils of the slope, which was a gentle slope with a gradient of approximately 12-13 degrees, rapidly slid for a long distance simultaneously with the occurrence of the earthquake. On the basis of post-test results, experts on landslide disasters pointed out that part of the slope, which contains a large amount of moisture from the abundant groundwater in the area, was liquefied by the effect of the seismic motion and caused the landslide. Since the disaster, the slope has been maintained by landslide control construction, such as the installation of landslide prevention piles. Moreover, although the existing water treatment plant is located next to the upper area of the slope, it would be determined that the regulating reservoir was constructed at a certain distance from that part of the slope (Fig. 4). Figure 4. Geological section of the construction site. 3.2 Residents’ feelings concerning construction of regulating reservoir Considering the severity of the landslide damage, we began explanations of the construction to local residents in 2001 during the design phase, with the aim of reaching an agreement before the start of construction. At a briefing, it was explained that the regulating reservoir is designed to ensure the seismic performance capable of resisting seismic motion as severe as that of the Great Hanshin-Awaji Earthquake (seismic motion level 2) in accordance with the guidelines “Seismic Design and Construction of Water Supply Facilities” (1995) (hereafter, Guidelines), and hence the seismic capacity would be greatly improved compared with the existing water treatment plant designed in the 1950s. In addition, it was also explained that the groundwater drainage system, which will be 194 installed to prevent any increase in the amount of groundwater flow into the slope during the drilling process, can suppress the groundwater level to lower than the present level, ensuring the safety of the ground. However, the residents who experienced the earthquake and landslide expressed strong anxiety regarding the possibility of water leakage caused by earthquake damage and requested the abolition or a considerable reduction of the scale of the plan. The opinions (requests) of the residents were as follows. • There are active faults around the construction site (Fig. 1). Intraplate earthquakes have continued to occur since the Great Hanshin-Awaji Earthquake and damage to structures has been reported. It cannot be guaranteed that the structures will not be destroyed. • Since the large-capacity water facility is to be constructed on the upper end of the slope on which the landslide occurred, there would be the possibility of increased danger to residents, including the occurrence of landslides, even though damage to the regulating reservoir may be small. • The safety of the area must be ensured during the service life of the regulating reservoir. Nishinomiya City, where this regulating reservoir is located, enacted the “Regulations for the Creation of an Earthquake-Resistant City” in 1995 and began designating the area within 100 m of either side of an active fault as a building regulation area. This regulating reservoir is beyond the regulation area because it is 300 m or more from an active fault. However, to remove the deep-rooted anxiety of the residents, it was decided that not only an evaluation of the effects of neighboring active faults but also measures to reduce the risk of secondary disasters in the event of damage to concrete structures should be examined. Moreover, we also decided to ask academic experts for their advice and evaluation as well as to endeavor to disclose information to residents in order to achieve an objective evaluation of the safety of the reservoir. 4. Measures for Reducing Risk Involved in Construction 4.1 Design Phase 1) Verification of antiseismic design based on Guidelines First, the effectiveness of the antiseismic design, to which the Guidelines were applied, was verified with respect to the effects of neighboring active faults. The projected seismic motion obtained on the basis of the Guidelines and two cases of seismic motion, calculated on the assumption that one of the two faults that are considered to have a potentially severe effect on this construction site becomes active, were compared. It was found that the projected seismic motion takes into account the seismic motion due to either of the two neighboring active faults, and therefore it was confirmed that sufficient seismic performance in line with the Guidelines can be ensured (Table 1). Table 1. COMPARISON OF DESIGN AND ASSUMED SEISMIC MOTION. Maximum ground surface acceleration (gal) Projected seismic motion based on Guidelines 1,200 Assumed seismic motion due to active fault (Arima-Takatsuki fault) 811 Assumed seismic motion due to active fault (Koyo fault) 766 Maximum seismic motion during the Great Hanshin-Awaji Earthquake 818 195 Furthermore, in the report on the investigation of damage due to the Great Hanshin-Awaji Earthquake [3], it is reported that no cracks would have been generated due to the lack of strength of the structure in the waterworks constructed on the basis of the 1979 Guidelines if the earthquake had not been accompanied by deformation of the ground. Also, on the basis of the performance of other similar reservoirs, it is considered that there is little possibility of the foundation ground under the regulating reservoir, which is mainly granite soil, being greatly damaged by earthquake. 2) Effect of ground surface displacement However, in the Kocaeri Earthquake in Turkey and the Ji-Ji Earthquake in Taiwan, which occurred successively in 1999, damage to structures caused by several meters ground surface displacement of the faults was observed. Because concrete structures may be damaged depending on the amount of ground surface displacement, academic experts have pointed out the necessity of predicting this effect and preparing countermeasures. Although the developmental mechanism of ground surface displacement has not yet been completely clarified, the amount of displacement can be quantitatively determined by a calculation using fault parameters [4]. As a result, the amount of displacement of the ground under the regulating reservoir has been estimated to be, at most, 0.5 m. This is considerably smaller than that (several meters) observed in the above-mentioned cases of damaged structures and is considered not to lead to structure failure, although this amount of displacement was evaluated to present a possibility of the generation of cracks. 3) Examination of measures for preventing water leakage Cracks generated in the regulating reservoir will cause water leakage, and when the water penetrates into the ground, a landslide may occur. Therefore, we decided to include measures in the design for mitigating damage caused by water leakage. As measures for preventing water leakage, we examined mitigating measures by assuming crack occurrence, in addition to preliminary measures aiming at preventing and suppressing cracks, such as increasing the number of shear reinforcements, preventing differential settlement at pipeline-structure joints, and reducing expansion joints which are conventional measures. The mitigating measures adopted in the construction are described below. • Providing a drainage channel In the construction, to remove the groundwater flowing into the site, collection channels were installed around the regulating reservoir to discharge the groundwater into neighboring rivers. Figure 5. Schematic of seepage control sheet and drainage channel. 196 Similarly, a drainage channel was provided for unexpected water leakage to prevent the water from penetrating into the ground. The main components of the facility are seepage control sheets installed at the bottom and along the sides of the regulating reservoir and special pipelines to drain the water collected in the sheets into the channels (Fig. 5). • Monitoring system installation It is difficult to always be aware of the current condition of the regulating reservoir because it is an unmanned facility. To solve this problem, areas of concern are continuously monitored by measurement equipment. The following five items that are considered to be related to the occurrence of landslides at the slope of concern are monitored: ground water level, soil slope, pore water pressure, rainfall, and amount of groundwater drained. These data are compiled in a PC in the on-site control room and alarms are transmitted to jurisdictional stations. 4.2 Response after start of construction We explained the measures for preventing water leakage to residents over approximately one year of meetings and gained their understanding. As a result, an agreement was achieved on the start of construction under the condition that these measures were included. However, even after the start of construction, we held meetings and provided information regarding the progress of the construction and the water leakage prevention measures, aiming at “ensuring reliability during the service lifetime”, which was one of the requests from the residents. 1) Construction phase • Tours of construction site Focusing on the construction and measures for preventing water leakage, tours of the construction site were held to highlight the progress so that the residents could confirm whether the construction was being properly conducted (Fig. 6). The tours were held during the process of equipping the facility with antiseismic measures, including seepage control sheets and the groundwater drainage system, as well as during the process of installing reinforcements. Information on the progress of the construction and safety management was regularly reported to local residents in writing in the form of leaflets. Figure 6. Scene of construction site tour. 197 • Verification of effects of measures and construction conditions Academic experts confirmed whether the effect of the measures for preventing water leakage were appropriate to the conditions of the construction site and whether the site was in a sufficiently functionable state (Fig. 7). The items confirmed were as follows. ♦ Seepage control sheet: condition of installed sheet ♦ Monitoring system: installation position of measurement equipment, operating condition ♦ Foundation ground: soil property, condition of groundwater drainage, ground condition before and after construction (future schedule) ♦ Structure of regulating reservoir: condition of bar arrangement of shear reinforcements, completion test Figure 7. Scene of construction confirmation by academic experts. 2) Completion and after (maintenance) • Disclosure of monitoring data One of the requests from the residents was to be able to confirm the ongoing monitoring of the regulating reservoir and the ground on-site. As a response to this, we displayed changes in the data with time in the local control room whenever requested (Fig. 8). In addition, we provided a large junction well to display the pipeline used to drain leaking water so that people could easily enter and observe the drainage . Figure 8. On-site monitoring system and monitoring data. 198 • Emergency discharge of standing water Because this regulating reservoir is far from the manned jurisdictional facility (pump station), concern was expressed by the residents about the initial response to an emergency. It was basically considered that there would be no problem in carrying out the measures to be taken immediately after an accident because the drainage pipe will be effective, but we also proposed to reduce the water level of the regulating reservoir by the emergency discharge of standing water as a more reliable strategy for reducing damage. In such an emergency discharge, water flow into the regulating reservoir will be stopped by stopping the pump located upstream, and at the same time, a motor-operated valve attached to the outlet pipe will be opened by remote control to forcibly discharge the standing water. Although the actual effect of this discharge will greatly depend on the water level and the condition of the downstream water reception area at that time, the anxiety of the residents was alleviated because a concrete methodology was presented. 5. Conclusions Since the Great Hanshin-Awaji Earthquake, residents living around active faults have continuously lived in fear of further activity. Regarding our construction in such an environment, we consider that our relationship of trust with the residents has been successfully, though slowly, established by not only presenting concrete safety measures against the possibilities of accidents but also enabling the residents to confirm the effects of the measures and by providing information on the progress of construction and on monitoring after the completion of the facility. The construction of this reservoir started in 2003 and was completed on schedule in March 2007. At present, the data accumulated during the construction that will be used for setting the critical values in the monitoring system are being analyzed. In addition, the examination of methods of sending and receiving warnings (voice information, E-mail, FAX, and others) and of sharing data with the disaster prevention agency are being discussed. In the case presented in this paper, it was essential to strengthen earthquake disaster countermeasures to ease the concerns of the residents because the area had previously been a disaster site. In Japan, which has a small land area and where houses are concentrated even around active faults, it is difficult to find new land suitable for constructing waterworks facilities. Moreover, most regulating reservoirs and drainage reservoirs are established at higher elevations in local areas into which housing developments are advancing owing to urbanization. Therefore, it is becoming increasingly important to ensure the safety of residents living near such facilities. When constructing public facilities, including waterworks, agreement with residents is indispensable. It is important for developers to establish a partnership with residents by, for example, actively providing information in consideration with local characteristics and residents’ needs. 199 (REFERENCES) [1] Mishima, K. 2000. "Restoration and Anti-Seismic Measures of Water Supply Facilities of Hanshin Water Supply Authority," U.S.-Japan Anti-Seismic Measures Workshop, 2000. [2] Planning and Examination Committee for Improving the Earthquake Resistance of Hanshin Water Authority, 1995. "Proposal for Improving the Earthquake Resistance of Hanshin Water’s Facilities," [3] National Institute of public Health, Japan Pipe Systems Research Center, Kokusai Suido Consultants Co., Ltd. 1996. “Research Report on Seismic Damage of Water Treatment Facilities by Great Hanshin Earthquake,” [4] Takada, S. Kitamura, I. 2001. “Simulation Model of Surface Fault Dislocation and Its Application to Recent Earthquakes,” Memoirs of Construction Engineering Research Institute, vol.43-B: pp.153-166. 200 5th AWWARF/JWWA Water System Seismic Conference SESSION 4 Seismic System Evaluations Mr. Kazutomo Nakamura, Japan Water Works Association, Tokyo, JAPAN – “A Case Study on How PIs Should Be Applied in Evaluating Seismic Performance Along with the Water Works Guidelines” Mr. Yasuhiko Sato, Japan Water Research Center, Tokyo, JAPAN – “Function Diagnosis Method to Improve Earthquake Resistance of Water Supply Facilities” Mr. Noboru Murakami, Hachinohe Water Supply Authority, Hachinohe, JAPAN – “Nejo Purification Plant Water System Facilities Today” Mr. Hidehiko Aihara, Yokohama City Waterworks Bureau, JAPAN – “The Quakeproof Diagnosis of Waterworks Facilities in Yokohama City” Ms. Crystal Yezman, Santa Clara Valley Water District, San Jose, CA, US – “Santa Clara Valley Water District Reliability Program, Implementing Improvements for Seismic Response” 201 202 A case study on how PIs should be applied -In evaluating seismic performance along with the water works guidelines- Kazutomo Nakamura ABSTRACT Japan Water Works Association (JWWA) published the drinking water supply service guidelines (the water works guidelines) in January 2006. The water works guidelines based on the concepts of the ISO/TC224 (Guidelines for the management and assessment of a drinking water supply service) that will be established as one of the international standards in 2007. The water works guidelines can be used to provide customers or council with information on the water works and to explain their situations in an easy way to make them understand logically. However, water utilities differ in their backgrounds such as geological, historical conditions and characteristics of their cities as well. Many of the water utilities are going to make their performance indicators (PIs) calculated by the water works guidelines open to the public. One hundred water utilities have released their PIs in the past three years. Almost of all water works can compare their PIs with other similar scale water utilities. This paper introduces practical examples for the seismic performance evaluation in particular with selected PIs of the water works guidelines. Kazutomo Nakamura, Senior Engineer, Training and International Department, Japan Water Works Association、8-9,4-Chome, Kudan-Minami,Chiyoda-ku, Tokyo , 102-0074, JAPAN 203 1. INTRODUCTION The Japan Water Works Association published “ Guideline for the management and assessment of drinking water service (JWWA Q 100)” [1](the water works guidelines) as a standard in January 2005. This standard is based on the concept of ISO/TC224 (Guideline for the management and assessment of a drinking water supply service) that will be established as one of the international standards in 2007. The water works guidelines consist of 137 items of PIs that can inform consumers of management data, keeping waterworks activities transparent, helping water utilities carry out accountability of a business, then consumers are being satisfied with their requests. The Ministry of Health, Labor and Welfare, administrating water utilities in Japan, made the water works vision [2] open to the public that indicates the future of Japanese water works and necessary measures for them to realize the vision. Every water utility is required to make its own water works visions [3]. The water works guideline is composed of the concept of the water works vision. Every water utility is recommended to make use of the water works guideline to compile its own vision. This paper reports practical examples for an earthquake resistance evaluation with PIs of the water works guidelines. 2. PRESENT STATUS OF JAPANESE WATER WORKS Water utilities in Japan have supplied safe and hygienic drinking water to their consumers and the population served stands at 97.2% as of March 2005. However, it is necessary for them to have to solve many problems in order to succeed the present safety and hygienic water supply systems into a next generation. 2.1 Necessity of facilities renewal Along with the number of population served has increased, in the period of high economic growth, most of Japanese water supply facilities had to be constructed from 1960s to 1980s. After 1990s, the advanced purification plants were installed to treat mainly polluted raw water. Forty years have passed since the facilities have constructed in the period of high economic growth era and some of the facilities are unable to adapt themselves to required performances. Water utilities have their aged facilities renewed in the near future. 204 180 155 160 140 120 110 100 75 80 73 60 38 40 30 20 10 8 0 9 9 9 45 969 79 00- -19 194 1959 1 19 -198 199 20 50- 0- 0- 1900 1945- 19 196 197 1980 1990- Figure 1. Number of purification plant to start operation [4] (more than 10,000m3/d of treatment capacity) 2.2 Retirement of staff The number of employees in water utilities nationwide comes up to about 56,000 [5] and about 40% of them are over fifties who will retire in ten years. The number of young generation is very few, due to management efficiency policy to reduce number of employees. Up to now, engineers and skilled workers of water works are in charge of operation and maintenance of their facilities. As the results of the staff have decreased to half, water works have to sort jobs they used to take care of themselves and to entrust to out-sourcing. In addition, it is necessary for water utilities to introduce a solid training system to help transfer technology, skills, and accumulated knowledge from shortly retiring staff to the next generation. 12,000 10,000 skilled 8,000 worker engineer 6,000 4,000 clerical worker 2,000 0 9 9 <25 34 39 54 59 25-2 30- 35- 40-44 45-4 50- 55- 60=< age group S ta tistics of Japanese W ater W orks in 2005 Figure 2. Number of water works employees classified by age 205 2.3 Decreasing of water demand The trend of water demand is decreasing by the spread of water conservation activity of customers, the effect of economic depression and increasing of water-reuse in industrial water. By the decrease of water demand, the income of water utilities is decreasing and the budget scale also became shrunk. With financial difficulties, some water utilities have to postpone the renewal of facilities, which have to be renewed, so that their earthquake resistant abilities should be decreased. 2.4 Requirement of water supply in disaster In case of the disaster happens, to supply water to the medical facilities, to the center of urban activities and to daily life of the citizen is essential. Especially in large city, if there is no water source as substitute for the water supply system, dependence on the water supply should be very high. Water utilities should be required to supply water the same as normal situations, even if in disaster as earthquake hits. It is known facts from many experiences that citizen can bear 3L of water in one day during a couple of days just after disaster happened, but gradually more amount of water for toilet, wash cloths and wash their body should be required. The earthquake proof water supply facilities and emergency water supply system are required to shorten the period of suspended time, and to supply water almost the same as usual conditions. 2.5 Stabilization of water service management According to the water supply law, the water works is principally administered on the municipality basis. There are 9,400 water works in Japan [5] and number of water works supplying to less than 5,000 populations are about 8,000 and more than 50,000 are only 422. Most of water works are categorized as small scale and are facing fragile business situations. Table１. Number of water services classified by scale （in 2005） 5,000 Under Under Under Under Under -- 101 More Under Popula- 500,000 100,000 50,000 30,000 10,000 (Small than constru Total tion ------scale 500,000 ction served 100,000 50,000 30,000 10,000 5,001 water Service) Number 24 190 208 209 506 454 11 7,794 9,385 of Water services 422 1,169 7,794 (4.5%) （12.5%） 83.0% 3. WATER WORKS VISION AND REGIONAL WATER WORKS VISION 3.1 Water works vision Japanese water works have many challenges as described above. The Ministry of Health, Labor and Welfare shows the desirable future and indicates the necessary 206 measures which the water works should address to realize the goals indicated by the water works vision. The goals of Japanese water works are represented in five keywords that are safety, security, sustainability, environment and globalization. Sustainability means the improvement of countermeasures against disasters. It was revealed [4] that only 20% of water purification plants and 23% of clear water reservoirs are equipped with earthquake resistant, according to the seismic diagnosis examined by water works themselves. In addition, ductile cast iron pipe with restraint joint, steel pipe and polyethylene pipe are installed with 13% of main pipelines (including raw water conveyance, transmission and distribution pipe) and 34% of water utilities compile water supply plan for the emergency. Based on these facts, three targets are set as specific countermeasures against earthquakes. a) All of purification plants, clear water reservoir and main pipeline should be earthquake resistant b) Every water utility should secure stable water supply depending on the area conditions, and to compile the emergency water supply plan in disaster, including an emergency repairing systems. c) Two goals mentioned above should be realized as soon as possible in the Tokai, Tou-nankai and Nankai areas where huge earthquakes being predicted. 3.2 Regional water works vision The water works vision shows the common goals and measures to be realized for all water utilities. Each water utility is requested to set own water works vision, namely the regional water works vision. Each water utility should analyze own business, and sets the goals fitting to their characteristics so that they have measures to reach their goals. When water utilities try to make out the regional water works vision, they are advised to make use of the water works guideline in order to analyze the present conditions, to evaluate a future prospect, to consider methods in reality and to set up the target. 4. THE WATER WORKS GUIDELINES 4.1 Necessity of water works guideline Water utilities in Japan are restricted to operate by public enterprises and their service areas to operate are fixed. In many countries, public sector takes charge of water supply. In recent years, many private companies show dynamic activities in the field of the water supply and those activities are expanding beyond country borders. Taking consideration of this kind of global business movements and water supply law permitting outsourced operation and maintenance, we can say that it is very difficult for only Japanese water works to keep isolating from global activities. In order to evaluate the water works based on the unified international standard, ISO/TC224 will be used as one of the international standards in 2007. This international standard stipulates and covers of the standard; it consists of element of structure of water supply system, methods of evaluation and basic concepts as well. However, the performance indicators are attached as an appendix, which has no restriction, due to environment of water works differ from each country. 207 4.2 Performance Indicators (PIs) The PIs are classified into six categories in total by adding a category of management to the existing 5 categories of the water works vision to show the present situation. The structure of the water works guidelines follows the ISO/TC224, the benchmarks are not set. The guideline contains the PIs that can show the problems of Japanese water works to solve as mentioned earlier and the future water works should be. 4.3 Evaluation by making use of the PIs The water works guideline evaluates the conditions of water works through calculation of 137 PIs. However, it is necessary to pay attention that the PIs are unable to express in numbers on natural and social environment of water works. The water works should not evaluate the conditions of water utilities only by using individual value but have to evaluate them by taking the mutual relations of another value into considerations. The purpose or usage of PIs differs by its positions. Water utilities use PIs to compare with similar water works and to analyze and to evaluate a series of variation of PIs. The PIs are useful tools to set the goal of project and to explain the process to reach or the benefit of project. By calculating PIs, it will be possible for us to explain the present status and target to the customer or the assembly in logically and clearly, because the water works can indicate its service activities in numerical values. In the field of water supply, industries, consulting farms and the competent authorities will be able to make use of the PIs for their purposes. Customers also make use of PIs to help them understand information on what water business situations stand, including about stable water supply and countermeasures against disasters. Customer can request specific information about the PIs that they want to know more. 4.4 PIs related to earthquake resistant One third of PIs relates to the evaluation of earthquake performance. The definition of some PIs relating to earthquake shown below; (1) 2103 ratio of aged pipeline: ratio of aged pipeline = ( length of pipeline exceeding statutory service life / total pipeline length) * 100 ( unit: % ) The length of pipeline exceeding statutory service life (km) is the full length of pipeline older than 40 years, the statutory service life (iron pipe) defined by the Municipal Enterprise Law. The total pipeline length (km) is the full length of conveyance, transmission and distribution pipe in use except for the decommissioned. (2) 2210 ratio of earthquake resistant pipeline: ratio of earthquake resistant pipeline = ( length of earthquake resistant pipeline / total pipeline length ) * 100 ( unit: % ) 208 The earthquake resistant pipe includes ductile cast iron, steel and high-density polyethylene pipes which are used for water conveyance, transmission and distribution, and which have earthquake resistant joints. The earthquake resistant joints used for the ductile cast iron pipe refers to various types of earthquake resistant joints, such as S, SII, NS, UF, KF, and PII. The steel pipe is limited to that having welded joints. The polyethylene pipe is limited if having thermal fused joints. Pipe in pipelines (PIP) and is shields are included anti-seismic structure. The length of earthquake resistant pipelines (km) is the full length of conveyance, transmission and distribution pipes having any type of anti-seismic joints mentioned above. The total pipeline length (km) is the full length of conveyance, transmission and distribution pipe in use except for the decommissioned. (3) 5013 number of pipeline failures: number of pipeline failures = ( number of pipeline failures / total pipeline length ) * 100 （number/100km） The number of pipeline failures (accidents) is the annual sum of accidents occurring in conveyance, transmission and distribution pipe (including aqueducts) in use, for example, ruptures, damage, coming off and leaking from fittings. Regardless of the causes (for example, another utility induces an accident) and the occurrence of water leaks, the accident includes failures in auxiliary equipment including valves and trouble with the pipes due to natural disasters, such as earthquakes, landslides and typhoons. The total pipeline length (km) is the full length of conveyance, transmission and distribution pipe in use except for the decommissioned. 5. APPLICATION OF THE PERFORMANCE INDICATORS Three years have passed since the guideline had been published. About one hundred water works have made their regional water works vision open to the public. Many PIs can be calculated directly from existing data, but some of PIs should be calculated from data gained by collected or arranged. In some water works, their basic data of PIs are not kept filed or classified, in case, data of facilities got lost or the reliability of data is kept low. Therefore those water works are unable to release their vision. Many water works should use PIs to analyze the present status, to set target and to explain logically. By using PIs, two types of examples can be summarized to evaluate the earthquake resistance improvement projects; one in self-evaluated, the other in a mutual relation of PIs. 5.1 Example of A water works A water works locates in southern part of the Kannto region and it released their ten-year management plan [6], which includes the improving projects for the countermeasures against disasters. The water works shows the present status and its goal in the form of PIs. Provided for predicted earthquake, existing pipelines have been 209 reinforced with seismic resistance ability based on a seismic diagnosis. The restraint joint pipes are installed in areas where liquefaction will be supposed to occur when the Kanto earthquake hits, and designated preparing areas against the Tokai earthquake. The concrete structures have been reinforced based on the diagnosis with the assumption of ground motion caused by the Tokai earthquake. Improving the seismic resistant ability of transmission and distribution pipeline, the restraint joint pipe are installed in the whole supply area from 2006 to 2015 and the ratio of earthquake resistant pipeline will increase from 9.5% to 16.6%. Table 2. The PIs of A water works code Performance indicator (PIS) 2004 2103 Ratio of aged pipeline (%) 6.3 2104 Annual renewal rate of pipeline (%) 0.49 2107 Newly installed pipeline (%) 1.3 2202 Trunk main failures（number/100km） 3.0 Water supply points density in emergency 2205 4.7 （number/100km2） 2210 Ratio of earthquake resistant pipeline (%) 9.5 5103 Number of pipeline failures（number/100km/year） 16.1 5107 Leakage rate (%) 5.9 5.2 Example of B water works B water works locates in southern part of the Kannto region. It released data of PIs [7] from 2003 to 2005 and compares its PIs with average PIs gained from six similar scale water works listed in the long period plan. Although the utility has been preceding the seismic resistant upgrade for large diameter pipeline, the ratio of earthquake resistant pipelines is kept lower than the average. The utility carries out the project for all pipelines to upgrade to earthquake resistant. Table 3. The PIs of B water works Average of Code Performance indicator 2003 2004 2005 Six similar waterworks 2103 Ratio of Aged pipeline (%) 4.7 4.8 5.7 － 2104 Annual renewal rate of pipeline (%) 0.83 1.19 1.39 1.0 2107 Newly installed pipeline (%) 0.32 0.66 0.51 － 2202 Trunk main failures（number/100km） 0.49 0.9 1.6 － Water supply points density in emergency 2205 2 36.0 36.3 36.3 － （number/100km ） 2210 Ratio of earthquake resistant pipeline (%) 7.1 9.9 10.4 16.0 Number of pipeline failures 5103 11.3 11.0 10.0 9.3 （Nnmber/100km/year） 5107 Leakage rate (%) 5.1 5.4 6.2 － The number of pipeline failures indicates the improvement, but still being kept lower than the average. Therefore, the utility announces to continue renewal of pipeline and to prevent from pipeline accidents happen. 210 5.3 Mutual relationship of PIs Some PIs should be considered individually, but almost of all PIs are related to each other. When pipelines are renewed to earthquake resistant pipelines, many effects are expected, as shown in Table 4. Table 4. Example of relationship of PIs Code Performance indicator Unit Expected effect Ratio of earthquake resistant Improving earthquake resistant 2210 % pipeline ability decrease amount of leakage and 1001 Resources availability ratio % to get a margin Violation ratio of water quality decrease violation of turbidity and 1104 % standard color 2202 Trunk main failures number/100km decrease accidents Ratio of revenue on water 3009 % increase, when to issue bond supply and bond interest 3015 Cost of water supply yen/m3 increase 3016 Water charge for domestic yen increase 3018 Ratio of revenue water % improve by decreasing leakage 3206 Complaints for water quality munber/1000 decrease number/100km/ 5103 Number of pipeline failures decrease year 5107 Leakage rate % improve by decreasing leakage 5109 Hour of water interruption or decrease hour supply turbid water 5.4 Application of mutual relationship of PIs By gaining co-relationship of PIs based on yearly data or other similar water works, it will be possible that formula of PIs could be indicated. As for the application of co-relationship of PIs, Mr. Ishii [8] describes the method on how PIs should be applied as a case study of the middle-scaled water utility, and he introduced necessity of renewal of aged pipelines in numerical values. He showed renewal of aged pipelines as a PI models, but I can say that new pipelines should be replaced with earthquake resistant pipelines, so that this model can be said as an evaluation of earthquake resistant pipelines. The service life of pipelines differs from soil conditions, traffics and grade of construction work. But the service life in the guidelines defined for 40 years the same years as depreciation periods in the accountings. In other words, the rate of aged pipeline increases at 2.5% every year. If annual renewal rate is lower than 2.5%, the aged pipelines would increase year after year. To explain the necessity of pipelines renewal (earthquake resistant) project with PIs logically, two cases of the cost versus benefit are calculated; one, the renewal project that starts immediately, the other, project that starts 10 years later. To keep reality in values, the PIs of existing C water works are calculated. The water utility has 57,000 of population served, with an average supply of 24,400m3/day, having 420km of pipeline length. The related PIs are shown in the Table 5. 211 Table 5. PIs of C water works Code Performance indicators value 2103 Ratio of aged pipeline (%) 19.8 2104 Annual renewal rate of pipeline (%) 1.7 2210 Ratio of earthquake resistant pipeline (%) 0.1 1117 Ratio of lead service pipe (%) 86.0 3015 Cost of water supply (doller/m3) 1.46 5103 Number of pipeline failures（number/100km/year） 25.7 5107 Leakage rate (%) 10.0 (1) Assumption The annual renewal rate is supposed to increase from 1.7% to 3.0% for 15 years of project periods. Existing cast iron pipe, steel pipe with screw joint, asbestos cement and hard PVC pipe would be replaced with the high performance ductile iron pipes as earthquake-proof pipes. By replacing existing pipes with high performance ductile iron pipes, the yearly aging ratio of replaced pipeline would be reduced to 1.5%. The cost of renewal project is estimated based on the construction cost classified by diameters. Along with renewal of distribution pipelines, customer meters also would be renewed. The leakage rate and the number of pipeline failures should be estimated from the formula of correlation with the ratio of aged pipelines. (2) Calculation result If the cost of this project should be paid only by the water tariffs, water charge would be increased by 0.46 doller/m3. As shown in Table 6, the ratio of earthquake resistant would increase to 45.1% and the leakage rate would be improved from 10.0% to 5.8%. And the ratio of lead service pipe and the number of pipeline failures are improved as well. Table 6. PIs of 15 years later 15years Code Performance indicator start later 2103 Ratio of aged pipeline (%) 19.8 7.3 2104 Annual renewal rate of pipeline (%) 1.7 3.0 2210 Ratio of earthquake resistant pipeline (%) 0.1 45.1 1117 Ratio of lead service pipe (%) 86.0 38.7 3015 Cost of water supply (doller/m3) 1.46 1.92 Number of pipeline failures 5103 25.7 7.6 （number/100km/year） 5107 Leakage rate (%) 10.0 5.8 In addition, the number of customer complaints on water quality decreases in the process of pipelines renewal, and expenses of water intake and purification can be estimated to decrease in the process of leakage rate improvements. 212 (3) Effect of postpone project The assumption is that the renewal project should be postponed by 10 years. And estimated goal is set as the same performance level of the project that starts immediately without 10 years delay. According to 10 years delay, the aging of facilities has progressed, based on these conditions, PIs of initial values are set for granted and to estimate of 15 years renewal project. The annual renewal rate of pipeline has to rise to 3.8%. The PIs of each year are listed in Table 7. Table 7. PIs of 25 years later 10years 25years Code Performance indicator start later later 2103 Ratio of aged pipeline (%) 19.8 27.8 8.7 2104 Annual renewal rate of pipeline (%) 1.7 1.7 3.8 2210 Ratio of earthquake resistant pipeline (%) 0.1 17.1 74.7 1117 Ratio of lead service pipe (%) 86.0 68.1 7.6 3015 Cost of water supply (doller/m3) 1.46 1.46 2.19 Number of pipeline failures 5103 25.7 27.1 4.0 （number/100km/year） 5107 Leakage rate (%) 10.0 11.5 6.0 The cost of water supply can be added by 0.73doller/m3. (4) The cost versus benefit analysis The calculation period covers for 55 years from now on, and the 1.7% of annual renewal rate should be kept constant except for 15 years of renewal project periods. The total cost consists of two expenses; operation and maintenance cost for 55 years and renewal project cost for 15 years. The benefit would be the decease of the leakage water volumes and the reduction of operation and maintenance expenses. The benefits of this project can be expected as the decrease of intake, raw water conveyance and purification cost, in addition to that the number of customer complaints on water quality would be declined and risk for earthquake would also be lessened, but they are not accounted. Table 8 shows the results of cost-benefit analysis. Table 8. The results of cost - benefit analysis start start 10years item unit immediately later Million Renewal+O&M 53.0 91.8 Cost Dollar Total 〃 53.0 91.8 Present value cost C 〃 40.9 48.4 Decrease of leakage 〃 26.3 17.4 Benefit Decrease of O&M 〃 47.7 61.0 Total 〃 74.0 78.4 Present value benefit B 〃 26.3 20.8 Ratio V=B/C ― 0.64 0.43 The differentiate rate of cost versus benefit comes up to at around 50%. The total investment cost reached 2 times as big as initial estimation. Water supply cost increased 213 from 0.46 doller/ m3 to 0.73 doller/m3. Although there are many tasks such as very simplified assumption, incomplete data and unable to calculate all related PIs, that would be solved but we can say that the results are useful enough for practical purposes. 6. CONCLUSION Three years passed since the water works guideline has been published as one of the standards of Japan Water Works Association. One hundred water utilities have calculated and made their regional water works vision open to the public by the year 2007. At present, PIs are released to compare with other similar water works and they became important tools to explain factors in their future goals. I think that from now on PIs should not be used as individual values but the important tools for analyzing and evaluating the project by taking co-relationship of PIs into considerations. This PIs method should be very useful for us to explain the necessity and future goal of the project in a way of clear and logically as well. This paper summarizes information described on the web sites of some water works and released papers. I prepared this paper to introduce how the water works guidelines should be applied into compiling the countermeasures against earthquakes in Japan, in particular, for “The Japan - U.S. Workshop on Water System Seismic Practices”. REFERENCES [1] Japan Water Works Association, 2005,“Guidelines for the management and assessment of a drinking water supply service (JWWA Q 100)” (in Japanese) [2] The Ministry of Health, Labor and Welfare, 2004, “The water works vision”, (in Japanese) [3] The Ministry of Health, Labor and Welfare, 2005, “The regional water works vision” (in Japanese), [4] The workshop of water works vision, 2005, “The Manual for water works vision”, Suidou sangyou sinbunsya (in Japanese) [5] Japan Water Works Association, 2007, “Statistics of Japanese water works in 2005” (in Japanese) [6] Waterworks and Electric Power Bureau, Public Enterprise Agency, Kanagawa Prefecture Government Home Page (in Japanese) [7] Yokohama City Waterworks Bureau Home Page (in Japanese) [8] Kenei Ishii, “Evaluation of the pipeline replacement project for drinking water system using performance indicators”, Journal of Japan Ductile Iron Pipe Association, No.79, 2006.10 (in Japanese) 214 Function Diagnosis Method to Improve Earthquake Resistance of Water Supply Facilities Yasuhiko Sato ABSTRACT Japan is one of the most earthquake prone countries in the world. In recent years, large scale earthquakes occurred in various locations. On the other hand, problems of lack of financial and technical resources in small drinking-water utilities have led to a situation where a significant number of facilities are decrepit and vulnerable to earthquake and other disasters. Survey in FY2004 shows the ratios of earthquake proofing were 20% for water treatment plants, 30% for distribution reservoirs and 14% for distribution mains. Water supply facilities must not only ensure a stable supply of water at normal times, but also minimize the risk of accidents and malfunction, especially in case of disasters. Preventive maintenance of the facilities is an important aspect in this regard. In addition to conventional maintenance procedures, function diagnosis to evaluate earthquake resistance should be implemented, in order to ensure that the facilities respond to the needs of society and its citizens. For these reasons, the Japan Water Research Center conducts various research studies to construct earthquake-resistant water supply facilities. This report will consist of 1) the evaluation of current function and diagnosis of water distribution facilities earthquake resistance from the “Waterworks Facilities Function Diagnosis Evaluation Manual”, which was created in order to effectively plan the functional improvement of facilities; and 2) Performance Indicators (PIs) in relation to earthquake resistance taken from the 137 items of the “Guidelines for the Management and Assessment of a Drinking Water Supply Service” published as a standard by the Japan Waterworks Association in January 2005. ______Yasuhiko Sato, Senior Researcher, Pipeline Engineering Dept. Japan Water Research Center, Toranomon Denki Bidg, Toranomon Minato-ku Tokyo, 105-0001, JAPAN 215 PURPOSE OF FUNCTION DIAGNOSIS AND EVALUATION MANUAL This manual has been prepared to facilitate the implementation of performance improvements to enable drinking-water utilities to independently evaluate the performance of their water supply facilities and decide what improvements are necessary. It outlines specific methods and procedures for managing the performance of facilities focusing on the following. 1) Evaluating the current performance of existing water supply facilities. 2) Preparation of plans for improving facilities that performance has declined. FUNCTION DIAGNOSIS AND EVALUATION PROCEDURES Function diagnosis and evaluation are divided into evaluation of current function, evaluation of function satisfaction, and formulation of improvement plans. These three types of evaluations are performed according to the procedures shown in Figure 1. Evaluation Category Evaluation Procedures Outline of Evaluation Current function level of each [Evaluation of current Overall function diagnosis system is evaluated using indexes. function] Current function of each individual To quantify the current Individual function facility that makes up the system is function level of facilities. diagnosis evaluated. Required and current function of [Evaluation of function Determination of function the system and the facilities that satisfaction] diagnosis results Function make up the system are compared diagnosis To make decisions as to the need for performance and disparities considered; improvements, taking into evaluation of scope for function Yes account those performance Has required level of improvement is evaluated. elements for which current function been met? If the required function has been performance evaluations and met, the function diagnosis and quantification would be No evaluation ends at this step. difficult. The system/facility to be improved, [Evaluations of improvement planning Setting of function the necessity, target, and outcome formulation] improvement targets of improvement. To determine improvement plans After the effectiveness of concerning the systems and facilities improvements, their consistency that require performance improvements. Setting of function with requirements, and the improvement methods reasonability of the improvement project are considered, the method of improvement is selected. (Preparation of function End improvement plans) (Implementation of function improvement project) Figure 1. Function Diagnosis and Evaluation Procedures 216 Overall Function Diagnosis The overall function diagnosis measures the current function level of each system as a whole using a fixed scale (evaluation indexes) in order to evaluate capacity relative to the facilities’ particular role and the state of maintenance. Overall function diagnosis is performed in the following order: completion of data sheet, calculation of system evaluation score, indication of results and consideration. The results of the calculations of system evaluation indexes and system evaluation points are tabulated with the individual function diagnosis results, and then the outcome is considered. The evaluation of earthquake resistance is performed apart from the data sheet according to the method described in “Diagnosis of facilities earthquake resistance”. Evaluation indexes during an overall function diagnosis shown in TABLE I. TABLE I. EVALUATIN INDEXES ON AN OVERALL FUNCTION DIAGNOSIS Function Category Evaluation Indexes 1) Securing ratio of optimal hydrodynamic pressure (%) Hydraulic function 2) Securing ratio of optimal hydrostatic pressure (%) 3) Distribution reservoir storage time (hr) Basic Performance 4) Total storage time (hr) 5) Water quality retention ratio (I) (%) Water quality function 6) Water quality retention ratio (II) (%) 7) Ratio of optimal residual chlorine (%) 8) Water distribution facilities earthquake resistance (-) 9) Available water capacity in emergencies (L) Earthquake resistance 10) Ratio of installed emergency stop valve (%) Structure 11) Ratio of earthquake-resistant distribution pipeline (%) Redundancy 12) Distribution water capability in emergencies (-) 13) Rationality of pipe configuration (-) 14) Ratio of coloring trouble (-) Comfort 15) Incidence of complaints (-) 16) Direct supply from distribution main (%) 17) Aging of mains (%) Operation 18) Aging of water distribution facilities (%) 19) Ratio of accidents of service pipe (%) Reliability 20) Ratio of pipeline failures (No./100km) 21) Ratio of interruption in supply (%) 22) Leakage rate (%) 23) Adequacy of water for firefighting (%) 24) Adequacy of drawing management (-) Maintenance Certainty 25) Saving of maintenance (-) 26) Adequacy of maintenance (%) Please see below for the calculation methods and the scoring criteria for evaluation points for the following earthquake resistance items on the overall function diagnosis and evaluation: water distribution facilities earthquake resistance, available water capacity in emergencies, ratio of installed emergency stop valve, and ratio of earthquake-resistant distribution pipeline. ● Water distribution facilities earthquake resistance The earthquake resistance of distribution reservoirs and other structures is evaluated using the results (or points) calculated in the structure with the weakest earthquake resistance after conducting an earthquake resistance diagnosis on major facilities except pipelines that frame 217 water distribution facilities (clear wells, distribution reservoirs, pre-stressed concrete tanks, ductile cast-iron pipes and cast-iron water pipe bridges, steel water pipe bridges, pump facilities, etc.) using the method detailed in 3) Diagnosis of Facilities’ Earthquake Resistance. ● Available water capacity in emergencies Calculation method: Available water capacity in emergencies (L/person) = {(Capacity of emergency storage tanks (m3)) + (Other available Capacity of all service reservoirs in emergencies (m3)} ÷ (Service population (person)) × 1000 Scoring criteria: 3 points : more than 10(L/person), 2 points : 5 or more – less than 10(L/person), 1 point : not 0 – less than 5(L/person), 0 point : 0(L/person) ● Ratio of installed emergency stop valve Calculation method: Ratio of installed emergency stop valve (%) = (Number of distribution reservoir with emergency stop valve (unit)) ÷ (Number of all distribution reservoirs (unit)) × 100 Scoring criteria: 3 points : more than 70%, 2 points : 50 or more – less than 70%, 1 point : not 0 – less than 50%, 0 point : 0% ● Ratio of earthquake-resistant distribution pipeline Calculation method: Ratio of earthquake-resistant distribution pipeline(%) = (Length of earthquake-resistant pipeline (m)) ÷ (Total pipeline length (m)) × 100 Scoring criteria: 3 points : more than 30%, 2 points : 15 or more – less than 30%, 1 point : 5 or more – less than 15%, 0 point : other than those above Diagnosis of Distribution Facilities Earthquake Resistance The following is a description of a method of diagnosis of distribution facilities earthquake resistance using an overall function diagnosis. The major facilities that make up the system about an overall function diagnosis are selected and entered on the check sheet of TABLE II. In the diagnosis method given in the table, the applicable category for each facility and each characteristic to be evaluated is selected, and the earthquake resistance to seismic intensities of 5, 6, 7 are evaluated (High, Medium, Low) by multiplying each of their respective weight functions. (Diagnosis example using the check sheet of TABLE II) Water pipe bridge made with ductile cast iron pipe or gray cast iron pipe For seismic intensity scale of 6: ground 1.4×ground deformation 2.0×foundations 1.0×Materials 1.4×height 1.4×beam construction 2.0×pipe type 1.0×span 1.0×shoes 1.0×width of crest 0.8×joints 0.5×seismic intensity scale 2.2 = 9.66. Earthquake resistance is thus within the range 14 or less, or “High.” Notes: 1) The seismic intensity scale used is determined taking into account the size of earthquakes considered destructive, which is the basis of the disaster precaution plans of the area in question, as well as the importance of the facilities, and other factors. 218 2) This diagnosis cites the evaluation method stated in the books given below and has been partially modified. (1) Report on Survey of Earthquake Countermeasures (March 1981), Japan Waterworks Association (2) Report on Technical Research and Development Concerning Prediction and Investigation of Waterworks Damage Due to Earthquake (March 2000), Japan Water Research Center 3) When diagnosis of the earthquake resistance of facilities are performed by means other than by the method described here, decisions may be based on those results. TABLE II. CHECK SHEET FOR DIAGNOSIS OF EARTHQUAKE-RESISTANCE (For water pipe bridges with ductile cast iron pipe or gray cast iron pipe) Facilities Water Pipe Bridge with Ductile Cast Iron Pipe or Gray Cast Iron Pipe Category Category Weight Points Remarks Function (example) Type I Type I: Diluvial and rocky ground in 1.0 good condition Ground Type II 1.4 1.4 Type II: Diluvial and alluvial ground that does not belong to Type I or Type III Type III Type III: Alluvial ground that is soft and 1.2 weak No 1.0 Effect on bridge foundations due to ground Ground 2.0 deformation and slope failure caused by deformation Possible 2.0 Yes 3.0 ground liquefaction Construction of With piles 1.0 1.0 foundations No piles, pile bend 2.0 Materials for Bricks, plain concrete 1.0 bridge abutment 1.4 and supports Other than those above 1.4 ＜5m 1.0 The height of the bridge abutment is Height of bridge ～ abutment and 5 10m 1.4 1.4 measured from the ground, and the height supports ＞ of the supports is measured from the river 10m 1.7 bed. Beams fixed on both ends, arches, 1.0 rigid frames Beam construction Beams fixed on one end, 2.0 2.0 continuous beams Simple beams 3.0 Pipe type Ductile cast iron pipe (DIP) 1.0 1.0 Gray cast iron pipe (CIP) 2.4 Span 1 1.0 1.0 ≧2 1.8 With device to prevent bridge 0.6 failure Shoes 1.0 Regular 1.0 Movable ends 1.2 Wide A/S≧1 0.8 A: width of crest, S: distance of edge Width of crest 0.8 (S= 0.5L+20m, however, the length of the Narrow A/S<1 1.2 bridge, L, is less than 100m.) Expansion, anti-slip-out 0.5 Joints mechanism type 0.5 Other joints 1.0 5 1.0 Levels according to the Japan Seismic intensity Meteorological Agency. scale 6 2.2 2.2 7 3.6 High 14＞ No damage Earthquake Medium 14 - 28 9.66 Water supply possible despite partial resistance damage Low 28＜ Severe damage or water suspension 219 Individual Function Diagnosis The major facilities that make up the system are diagnosed using the facility evaluation points based on the individual function diagnosis sheet. The current state of facilities is examined through various questions concerning the state of facilities’ functionality, maintenance, decrepitude, and technical level, with points from the evaluation column answers added to obtain a facility evaluation score. INDICATION AND EXAMINATION OF EVALUATION RESULTS An overall function diagnosis and an individual function diagnosis are performed and a table of results is prepared as shown in TABLE III. The system evaluation scores in the overall function diagnosis is calculated from the evaluations, expressed as indexes, of the current level of the individual facilities of each system, and provide an overall evaluation of function levels by component system. Considered together with the evaluation scores of the individual facilities of the system in the individual function diagnosis, the current performance level of the facilities is ascertained. In the case of the three distribution systems A – C as shown in TABLE III, for example, the overall function diagnosis result is indicated by entering the sum of the points assigned to each of the evaluation indexes (i.e. System A, 54 points; System B, 81 points, System C, 79 points). The individual function diagnosis results are indicated by entering scores representing the evaluation of the state of function, maintenance, aging, and technical level of each of the facilities that make up each system, along with the overall facilities evaluation score. Then a chart as shown in Figure 2 is prepared based on this data. These tables and charts can be interpreted to mean that the higher the system evaluation scores are, more reliably the system as a whole functions; and that the higher the individual facilities evaluation scores are, the better the performance of each facility. 220 TABLE III. EXAMPLE OF RESULT OF FUNCTION DIAGNOSIS Overall Function Diagnosis Evaluation Index System A System B System C Securing ratio of optimal hydrodynamic pressure 1 3 2 Securing ratio of optimal hydrostatic pressure 2 2 3 Distribution reservoir storage time 2 3 2 Total storage time 2 3 2 Water quality retention ratio (I) 1 2 3 Water quality retention ratio (II) 2 1 3 Ratio of optimal residual chlorine 2 1 2 Water distribution facilities earthquake resistance 1 2 2 Available water capacity in emergencies 2 3 2 Ratio of installed emergency stop valve 2 3 2 Ratio of earthquake-resistant distribution pipeline 1 3 3 Distribution water capability in emergencies 2 2 3 Distribution Rationality of pipe configuration 1 3 2 Facilities Ratio of coloring trouble 3 3 2 Incidence of complaints 2 3 2 Direct supply from distribution main 0 2 3 Aging of mains 1 2 2 Aging of water distribution facilities 1 2 2 Ratio of accidents of service pipe 1 2 3 Ratio of pipeline failures 2 3 2 Ratio of interruption in supply 2 2 3 Leakage rate 1 2 3 Adequacy of water for firefighting 2 3 2 Adequacy of drawing management 3 3 3 Saving of maintenance 1 2 2 Adequacy of maintenance 2 3 2 System evaluation points 54 81 79 Individual Function Diagnosis System State of State of State of Technical Facilities Distribution Facilities Function Maintenance Aging Level Evaluation Distribution reservoir A 60 50 30 50 30 System Distribution reservoir B 70 60 50 70 50 A Distribution reservoir C 90 90 80 80 80 Distribution pump A 70 70 50 60 50 Distribution reservoir D 70 60 70 80 60 Distribution reservoir E 100 90 90 100 90 System Distribution pump B 80 80 80 90 80 B Emergency generation facilities 90 80 80 80 80 Power control facilities 80 70 70 80 70 Distribution Reservoir F 70 80 70 80 70 Distribution pump C 70 80 80 60 60 System Emergency generation facilities 70 70 80 70 70 C Power control facilities 80 90 70 70 70 Instrumentation equipment 80 80 90 80 80 221 SystemＡ系統 A Distribution配水池 ReservoirＡ A Distribution配水池Ｂ Reservoir B Facilities施設 Facilities施設 Securing ratio of optimal hydrodynamic Evaluation評価 Evaluation評価 pressure 適正動水圧確保率 100 100 Securing ratio of optimal hydrostatic適正静水圧確保率 pressure 80 80 60 60 Distribution reservoir storage time配水池貯留時間 Technical技術 40 State機能 of Technical技術 40 State機能 of Total storage time 総配水貯留時間 Level水準 20 Function状況 Level水準 20 Function状況 0 0 Water quality retention ratio (Ⅰ水質保持率（Ⅰ）) Water quality retention ratio (Ⅱ水質保持率（Ⅱ）) State of State of Ratio of optimal residual chlorine最適残留塩素割合 老朽化State of State管理 of 老朽化 管理 Aging Maintenance 状況Aging Maintenance状況 状況 状況 Water distribution facilities earthquake配水施設耐震性 resistance Available water capacity 緊急時利用可能容量in emergencies Distribution Pump A Ratio of installed emergency緊急遮断弁設置割合 stop value Distribution配水池Ｃ Reservoir C 配水ポンプＡ Facilities施設 Facilities施設 Ratio of earthquake-resistant distribution配水管耐震化率 Evaluation pipeline Evaluation評価 評価 Distribution water capacity 緊急時配水対応度in emergencies 100 100 80 80 Rationality of pipe configuration配管形態合理性 60 60 Technical State of Ratio of coloring trouble 着色障害発生割合 Technical技術 40 State機能 of 技術 40 機能 Level水準 20 Function状況 Level水準 20 Function状況 Incidence of complaints 苦情発生件数割合 0 0 Direct supply from distribution main直結給水率 Aging of mains 配水老朽管構成割合 State of State of 老朽化State of State管理 of 老朽化 管理 Aging of water distribution facilities配水施設老朽度 Aging Maintenance 状況Aging Maintenance状況 状況 状況 Ratio of accidents of water給水装置事故発生率 supply equipment Ratio of pipeline failures 配水管事故発生割合 Ratio of interruption in supply断水発生件数率 Results of Individual配水施設個別診断結果 Diagnosis of Distribution Facilities Leakage rate 漏水率 100 Adequacy of water for firefighting消火用水確保充実度 90 80 全体機能診断評価得点Score of overall function Adequacy of drawing management diagnosis points 図面管理充実度 70 Saving of maintenance 管理省力度 60 Adequacy of maintenance 保全管理充実度 50 得点 40 0123 30 20 System Evaluation Points Points Evaluation System Results全体機能診断結果 of Overall 10 Function Diagnosis 0 Distribution Distribution Distribution Distribution Reservoir配水池Ａ A Reservoir 配水池Ｂ B Reservoir 配水池Ｃ C 配水ポンプＡPump A Distribution施設名 Facilities Distribution facilities System A supplies water to an old urban district. Asbestos cement pipe and lead pipe remain and lead to low earthquake resistance, water leakage, and many complaints. The system is also connected to the performance of water treatment plant C, and distribution pipe, consisting of many dead end pipes, often become detente, causing a low water quality maintenance ratio (I). Earthquake resistance is particularly low in distribution reservoir A, and because pipe serves both as transmission and distribution pipe, the priority for improvement of this reservoir is considered higher than other distribution reservoirs. From periodic inspections, the insulation resistance of distribution pump A was judged to be declining and aging was scored lower than in the previous performance evaluation. Although priority had to be given to measures against residual chlorine in distribution facilities System B, as for System A as a whole, it is necessary to consider replacement of pipeline and improvement of distribution reservoir A and distribution pump A. Figure 2. Example of Results of Function Diagnosis System A 222 GUIDELINES FOR THE MANAGEMENT AND ASSESSMENT OF A DRINKING WATER SUPPLY SERVICE Undertakings of the Japan Water Research Center The Japan Water Works Association (JWWA) published “Guidelines for the management and assessment of a drinking water supply service” in January 2005 as JWWA standards (Q 100). The JWWA Guidelines define 137 PIs, including indicators specified in Japan, that is, those concerning earthquake countermeasures. In addition, statistical data on Japan’s drinking-water utilities, such as population served, amount of water supplied, and financial indicators, are published every year, from which 49 drinking-water utility PIs can be calculated. The Japan Water Research Center determined these PIs based upon which distribution histograms of each PI were prepared and analyses were performed. HISTOGRAMS About the Histograms The guidelines define 137 PIs that are categorized under six objectives — reliability, stability, sustainability, environment, management, and international. The histograms here show four PIs — the ratio of earthquake-resistant treatment facility, the ratio of earthquake-resistant pumping station, the ratio of earthquake-resistant service reservoir, and the ratio of earthquake-resistant pipeline — regarding the earthquake-resistance of 41 drinking-water utilities that have announced provisional values. Percentile values are shown on the right of each histogram. To obtain a percentile of a group of data values, first sort the data in order of value from the lowest to the highest. If there are 100 data values, the 5th percentile is the 5th value in order, 20th percentile is the 20th value in order, and any other percentiles can be found in the same procedure. The 50th percentile is the median. As these figures show, drinking-water utilities differ substantially in a degree of progress. Ratio of Earthquake-Resistant Treatment Facility In the JWWA Guidelines, the ratio earthquake-resistant treatment facility is given by the following formulas. Ratio of earthquake-resistant*1 treatment facilities (%) = (capacity of earthquake-resistant purification facilities (m3/day)/ capacity of all purification facilities (m3/day)) × 100 Figure 3 shows the histogram of ratio of earthquake-resistant treatment facility. It is clear that the earthquake-resistance efforts are not progressing by looking at the ratio of the earthquake-resistant treatment facilities as approximately 60% of all utilities fall under less than 5%, and approximately 90% of all utilities fall under less than 50%. *1) Designed according to level 2, rank A earthquake-resistance standards as prescribed in the Seismic Design Guideline for Waterworks. 223 20 100% 18 16 80% 14 th 12 60% 95 percentile 56.8 th 10 80 percentile 28.4 事業体数 8 40% Median 0.0 20th percentile 0.0 6 th Number utilities of 5 percentile 0.0 4 20% 2 0 0% 5-10 5以下 10-15 15-20 20-25 25-30 30-35 35-40 40-45 45-50 50-55 55-60 60-65 65-70 70-75 75-80 80-85 85-90 90-95 95-100 Ratio of earthquake-resistant2207 浄水施設耐震率（ treatment％） facilities (%) Figure 3. Ratio of earthquake-resistant treatment facilities (Number of utilities: 32) Ratio of Earthquake-Resistant Pumping Station The ratio of earthquake-resistant pumping station is given by the following formulas. Ratio of earthquake-resistant*1 pumping station (%) = (capacity of earthquake-resistant pump stations(m3/day) / capacity of all pump stations(m3/day)) × 100 Figure 4 shows the histogram of ratio of earthquake-resistant pumping station. Just as same as the treatment facilities, by looking at the ratio of the earthquake-resistant pumping stations, it is clear that the earthquake-resistance efforts are not progressing as approximately 40% of all utilities fall under 5%, and that 70% of all utilities fall under less than 50%. 20 100% 18 16 80% 14 th 12 60% 95 percentile 71.6 th 10 80 percentile 60.4 Median 15.7 事業体数 8 40% 20th percentile 0.0 6 th Number of utilities 5 percentile 0.0 4 20% 2 0 0% 5-10 5以下 10-15 15-20 20-25 25-30 30-35 35-40 40-45 45-50 50-55 55-60 60-65 65-70 70-75 75-80 80-85 85-90 90-95 95-100 Ratio of earthquake-resistant2208 ポンプ所耐震施設率（ pumping％） station (%) Figure 4. Ratio of earthquake-resistant pumping station (Number of utilities: 37) 224 Ratio of Earthquake-Resistant Service Reservoir The ratio of earthquake-resistant service reservoir is given by the following formulas. Ratio of earthquake-resistant service reservoir (%) = (capacity of earthquake-resistant service reservoirs (m3) / capacity of all service reservoirs (m3)) × 100 Figure 5 shows the histogram of ratio of earthquake-resistant service reservoir. In regards to the ratio of earthquake-resistant service reservoirs, approximately 70% of all utilities occupy less than 50%. However, approximately 20% of all utilities fall under less than 5%, and, while it is still an insufficient amount, the earthquake-resistance is progressing compared with the purification facilities and the pump stations. 10 100% 9 8 80% 7 th 6 60% 95 percentile 87.8 th 5 80 percentile 54.7 事業体数 4 40% Median 24.2 20th percentile 8.2 3 th Number utilities of 5 percentile 0.1 2 20% 1 0 0% 5-10 5以下 10-15 15-20 20-25 25-30 30-35 35-40 40-45 45-50 50-55 55-60 60-65 65-70 70-75 75-80 80-85 85-90 90-95 95-100 Ratio of earthquake-resistant2209 配水池耐震施設率（ service％） reservoir (%) Figure 5. Ratio of earthquake-resistant service reservoir (Number of utilities: 37) Ratio of Earthquake-Resistant Pipeline The ratio of earthquake-resistant pipeline*2 is given by the following formulas. Ratio of earthquake-resistant pipeline (%) = (length of earthquake-resistant pipelines (km)/ total pipeline length (km)) × 100 Figure 6 shows the histogram of ratio of earthquake-resistant pipeline. As this figure show, drinking-water utilities differ substantially in a degree of progress they have achieved in pipeline improvement measures. Because Japan’s water pipeline system still includes asbestos cement pipes and grey cast iron pipes, replacement of the pipes is a major component of measures to improve earthquake resistance and to prevent water leakage and interruption of water supply. *2) Ductile cast iron pipes with earthquake-proof joints, steel pipes with welded joints, and high-density polyethylene pipes with fused joints are considered high performance earthquake-proof pipe. 225 10 100% 9 90% 8 80% 7 70% 6 60% 95th percentile 25.8 5 50% 80th percentile 17.4 事業体数 4 40% Median 9.4 th 3 30% 20 percentile 3.2 th Number of utilities of utilities Number 2 20% 5 percentile 1.1 1 10% 0 0% 1-2 2-3 3-4 4-5 5-6 6-7 7-8 8-9 9-10 30超 1以下 10-11 11-12 12-13 13-14 14-15 15-16 16-17 17-18 18-19 19-20 20-21 21-22 22-23 23-24 24-25 25-26 26-27 27-28 28-29 29-30 Ratio of2210 earthquake-resistant 管路の耐震化率（ ％）pipeline (%) Figure 6. Ratio of earthquake-resistant pipeline (Number of utilities: 39) CONCLUSION Water supply facilities must not only ensure a stable supply of water at normal times, but also minimize the risk of accidents and malfunction, especially in case of disasters. Preventive maintenance of the facilities is an important aspect in this regard. In order to steadily resolve the current functionality issues with water supply facilities, considerations must be given to the functions in demand, and thereafter, optimal and concrete functional improvement plans must be drafted and implemented with efficiency. In order to accomplish this, the function diagnosis prescribed in this manual must be utilized in addition to the existing regular maintenance, and the efforts must be made to realize a higher function. It is also extremely important for drinking-water utilities to calculate PIs themselves so that it can be objectively discerned where the utility is positioned amongst other utilities nationwide. Moreover, in line with improving services, it is also necessary to actively publicize and explain PIs to the diet and consumers in order to gain their understanding and ensure business transparency. Publicizing and providing explanations of PIs in this manner will make it possible to explain about the current operations and technology situation of drinking-water utilities, and is an effective step in promoting future business plans such as the earthquake-resistance of facilities. REFERENCE [1] Japan Water Works Association. March 1981. “Report on survey of earthquake countermeasures” [2] Japan Water Research Center. March 2000. “Report on technical research and development concerning prediction and investigation of water works damage due to earthquake” [3] Japan Water Works Association. January 2005. “JWWA Q 100 Guidelines for the management and assessment of a drinking water supply service” 226 Nejo Purification Plant Water System Facilities Today KEN-ETSU KOJIMA, NOBORU MURAKAMI ABSTRACT The results of the quakeproof diagnosis for the 40-year old Nejo purification water system facilities were reported during the 1st US and Japan Workshop on Seismic Measures for Water Supply. The diagnosis made on the intake facility, water conveyance facility, purification plant, transmission pipes and service reservoir was that all these were inferior in quakeproof performance. However, at that time, no conclusions were given that could either be implemented, or that should reinforce existing institutions, or build new ones. According to the diagnosis, the water conveyance pipes and tunnels needed to be rehabilitated, together with the route and transmission pipes. All civil engineering structures and architectural building could, however, be reinforced against earthquakes. Extending the life and strength of the 40-year old plant against earthquakes by way of reinforcements may be difficult at this stage. This is because each component system has its own strength, such as the accelerator, or the heart of a purification plant. What is needed, instead, is to consider how to keep a balance among all purification plant water system to function properly against earthquakes. It was decided, therefore, to unify the institutions, such as intake tower, water conveyance pumping station, water conveyance pipes and Nejo purification plant, with Hakusan purification plant water system. Together with this decision, is the preservation of the Nejo service reservoir by adding a reducer valve and other mechanical equipment to reduce the risk of an accident because its service area is in the downtown area and its distribution pipes are quite aged. The Nejo service reservoir was examined for quakeproof reinforcement and rehabilitation, by considering its ground condition, its neighboring residential area and a steep slope of its north side. It was decided that the existing service reservoir was to be utilized as sand guards and a new 7,200m3 stainless steel one be built. Seven years has passed since 2000, and this report outlines the processes on the decisions made for each facility, together with the details of the examination made on Nejo service reservoir. Noboru Murakami, Management Planning Division, Leader of General Policy, Hachinohe Regional Water Supply Authority, 1-11-1 Minami- Hakusandai, Hachinohe, Aomori Japan 039-1112 227 INTRODUCTION After the Tokachi-Oki Earthquake in 1968, the Hachinohe Regional Water Supply Authority (Hereafter “the Authority”) started to actively work on the issue of making its water facilities quakeproof especially when the emergency water supply by feed water tank lorries was found out to be quite inefficient, Among the water facilities found to be the weakest and most vulnerable were its water pipes. The Authority likewise reported the results of its studies to the Japan and U.S. Workshop on Seismic Measure for Water Supply that has since been already held four times. In 1995, the Hansin-Awaji Earthquake struck, and the water facilities again were damaged affecting the lives of the residents in the water service area. The necessity of making the water treatment facility system quakeproof was urgently recognized. In this connection, therefore, the Authority undertook the diagnoses of the existing water treatment facilities, including the water pipes, in 1998. It should be noted that the Nejo Water Treatment Plant facilities were constructed over 40 years ago. The quakeproof diagnoses for these facilities were much awaited, and were subsequently reported on in the 1st Japan and U.S Workshop on Seismic Measure for Water Supply. The result of diagnoses revealed that the intake facility, transmission facility, water treatment facility and waterline had insufficient quakeproof abilities. However, the full courses of action on the result of the diagnoses for the water system have not been decided, except for the expansion plan for the facilities. After seven years, the expansion plan is almost completed. In addition, water demand and supply have been stabilized enabling the quakeproof analysis to be made for each facility. This will become the basis whether an existing facility will be rehabilitated, or if a new facility needs to be constructed. The result of the study, which includes the rehabilitation of the service reservoir with the construction of a stainless structure, is the subject of this paper. RESULTS ON QUAKEPROOF DIAGNOSIS OF NEJO WATER TREATMENT PLANT FACILITIES There were several approaches in studying the structural strength of the water treatment facilities. These were through visual observation, concrete compression test, concrete neutralization test, Schmidt hummer test and drilling survey. The documents referred to or utilized in quakeproof diagnosis were the following: for architectural buildings, referral document was the “Total quakeproof diagnosis for government office – rehabilitation standard and its description” (Minister for Construction Government Office Building and Repairing Department, 1996); for civil engineering buildings, it was the “Guideline and description of quakeproof design criteria for waterworks facilities” (Japan Water Works Association ,1997); and for water pipes, data was studied from test drilling, site survey and drawings. Tategami Intake Tower (Intake) Photo 1 The Tategami intake tower has been found to have quakeproof ability. While the structure lacks stability and may fold up, sway or move if struck by a severe earthquake, it can be strengthened by installing an anchor behind it unto the bedrock. 228 Photo 1 Tategami Intake Tower (Intake) Tategami Pump Station Photo 2 The Tategami Pump Station was built using both spread and independence foundation techniques, thus the building is deeply penetrated into the ground giving it extra stability in the event of an earthquake. However, the entire building is still assessed to have insufficient quakeproof ability because the girders at the superstructure are bent and have cracks. The building has also a shortage of ultimate lateral strength, so that applying X-type steel braces and K-type steel braces on the walls and openings and at the intermediate walls and columns will help increase shearing force. Photo 2 Tategami Pump Station Tunnel/Water Transmission Pipe Photo 3 The tunnel was built using 25 cm thick plain concrete. The result of structural analysis on the tunnel/water transmission pipe reveals that the structure only functions to prevent a landslide but not to receive stress from the ground. To remedy this situation, the structure can be back-filled since the natural ground properties and balance allow for this type of quakeproof method. The thickness of the water transmission pipeline, which was checked in the areas where this was visible, confirmed that the pipes do have the necessary thickness although the pipe joints are not quakeproof. The survey revealed that the bolts at the A-type joints are corroded and that pipe replacement 229 must be done. Photo 3 Tunnel/Water Conveyance Pipe Nejo Water Treatment Plant Photo 4 The construction of the Nejo Water Treatment Plant utilized spread foundation resulting in deep ground penetration. Since differential settlement did not occur, problems such as folding and sliding are not expected. The building structure, however, has large openings which result in a shortage of ultimate lateral strength. In addition, the bending stress caused cracks particularly on the girders at the superstructure where it was modified, such as the roof deck which was used as a warehouse or a break room. It can be concluded, therefore, that the building has insufficient quakeproof ability. As the seismic retrofitting method, carbon fiber reinforcement was applied for girders, while the X-type steel braces were applied on the 1st floor since it has the required ultimate lateral strength; and K-type steel braceswere applied on the lower ground floor. Photo 4 Nejo Water Treatment Plant Transmission Main There was no corrosion observed on the surface of the main transmission pipe, neither were there issues related to the result of the soil analyses. However, since the A-type joints, which do not have quakeproof ability, were used, it would be best that said water pipes are to be replaced. 230 Nejo Distribution Reservoir Photo 5 In the Nejo Distribution reservoir, the stresses on girders walls, the walls of pipe gallery, slabs and foundation slabs exceeded the allowable stress. It means that the structure has been kept by its material strength and it is not entirely safe. Photo 5 Nejo Distribution Reservoir The result of liquefaction study validates that no ground damage will occur because the reservoir sits on a geologic stratum consisting of the sandy soil layer. The slope upon which the reservoir was constructed was made by banking material (see Fig.1) that has the necessary safety ratio for normal times and during earthquake situations. (South – North) Fig.1 Stratum Sectional Assumed Illustration for Nejo Distribution Reservoir The reinforcing methods for the structure are Placing Concrete Method, Carbon Fiber Reinforcement Method and Adding Concrete Method. Among all these methods, the best is the “placing concrete method” because of the cost advantage; the water shut performance, and its ease of use or workability. QUAKEPROOF DESIGN IN VIEW OF INTEGRATION TO OTHER FACILITIES Quakeproof analysis was done for each facility at the Nejo water treatment plant system. While it is possible for those facilities except water pipes to undergo seismic retrofitting, this might not extend the 231 durability of the buildings because of its age. The quakeproof study therefore considers the entire water system, not only the individual facility. As illustrated on Fig.2, the Mabechi River is the water resource for Nejo water system but there is Kawanakajima Intake (see Photo 6) 350 meters upper stream. HWL 104.57 Hakusan Hakusan reservoir purification V=40,000m3 plant HWL 71.25 φ1200 water conveyance pipe Nejo reservoir V=10,700m3 Nejo purification φ800 water conveyance pipe plant downtown neighboring areas Tategami 350m Kawanakajima intake pumping intake pumping station station Mabechi River Fig.2 Water Supply System by the Mabechi River Photo 6 Kawanakajima Intake The Kawanakajima Intake facility has an actual pump capacity of 165,000m3/day. If a pump that has the intake capacity of Tategami Intake is installed here, then the operations of the Tategami pumping station facility can be halted. The 1,200 millimeters steel water transmission pipe from Kawanakajima Intake facility to Hakusan Water Treatment Plant has quakeproof ability. This pipeline transmits raw water. There is also the issue about the alternative water treatment plant, constructed in 2005, which receives water (50,000 m3/day) from another water source. Raw water is purified at both the new and existing water treatment plants. (see Fig.3). 232 Since the new facility has not yet been built, both the new and the existing facilities are presently utilized for water purifying which is equivalent to the water right (80,520 m3/day) in the Nejo Water Treatment Plant. The existing facility (50,000 m3/day) is being studied for improving the water purifying ability to match the water right from the Mabechi River (80,520 m3/day). It is also being studied for quakeproof ability. Yomasari Dam Korekawa receiving receiving Kawanakajima pumping station well flow meter well pumping station P M P 4.5km 3.7km Niida Mabechi River purification purification River water right: plant plant water right: 58,074m3/D (in 2005) (in 1975) 80,520m3/D reservoir under construction Fig.3 Mutual Flexibility of Raw Water The Hachinohe old city is provided with stable water pressure from the Nejo Distribution Reservoir service area. However, the changing water head causes the old pipes to leak. The study recommends that the water reservoir be rehabilitated and be utilized as a water facility instead. But insofar as the Nejo Water Treatment Plant is concerned, utilizing it as water purifying facility will need large-scale reinforcement. Therefore, it is best to utilize the facility as a warehouse or a water pipe training facility so that only small reinforcement will be required to match its use. As a result of the study, Nejo Water Treatment Plant water system facility is modified as follows: The facilities to be abolished or demolished and integrated Tategami Intake Tower (Intake Port), Tategami Pump Station, Water Conveyance Pipe, Tunnel, Transmission Main The facility to be converted to another purpose Nejo Water Treatment Plant The facility to be rehabilitated Nejo Distribution Reservoir 233 STUDY ON NEJO DISTRIBUTION RESERVOIR TO BE REHABILITATED Total capacity of the distribution reservoir (see Fig.4) is designed at 10,700m3 (8,200m3 for No.1 & No.2 and 2,500m3 of No.3). However, it is necessary to perform the renewable construction works and stop utilizing the existing reservoir because the construction of reservoir with an equivalent capacity in the empty space within the existing site is impossible due to land constraint. Consequently, only No.1 and No.2 were considered as the renewable reservoirs from the viewpoint that a secondary disaster can occur considering that both sites are around a steep edge of banked up surface which reduces the incidental risks taking into account the change in the distribution method (water-distribution by pressure reducing valve on the Hakusan Distribution System). Both reservoirs of No.1 and No.2 will be left without additional reinforcement and renewal. After completion, however, No.3 reservoir will provide continuous supply during the construction period. To keep pace with the reduced capacity, it is necessary to install a partial pressure reducing valve to the renewed reservoirs as a counterbalance. Fig. 4 Plane View of the Distribution Reservoirs Overview of Structural Type to be Studied Newly-constructed RC Structure Newly-constructed SUS Steel Replaced RC Structure Overview Overview (see Fig. 5) Structure Overview (see Fig. 6) (see Fig. 7) The reservoir with RC structure Demolishing the top plate and Demolishing the top plate and will be newly built by keeping the column, the rectangular SUS column, the reservoir with RC side wall at the reservoir’s distribution reservoir will be structure will be rebuilt within the northern side as a retaining wall newly built within the old old building frame by retaining and demolishing the other building frame by retaining the the sidewall/bottom plate as an members of framework to side wall/bottom plate as an exterior frame to mitigate impact maintain slope stability. exterior frame to mitigate impact on the surrounding ground and/or on the surrounding ground and/or maintain slope stability. maintain slope stability. 234 existing outer wall Fig. 5 Newly-constructed RC Structure Overview existing outer wall Fig. 6 Newly-constructed SUS Steel Structure Overview existing outer wall Fig. 7 Replaced RC Structure Overview Capacity Newly-constructed RC Structure Newly-constructed SUS Steel Replaced RC Structure Structure 7,860 m3 7,220 m3 6,960 m3 Seismicity, Water Tightness, Corrosion Resistance, Durability 235 executing the internal coating water-resistance. Maintenance Constraints of Construction Construction Period Newly-constructed RC Structure Newly-constructed SUS Steel Replaced RC Structure Structure 16.5 month 13.0 month 14.0 month (Demolition : 3.0 months) (Demolition : 1.5 months) (Demolition : 1.5 months) Economy (Total Cost) Newly-constructed RC Structure Newly-constructed SUS Steel Replaced RC Structure Structure Cost Ratio : 1.08 Cost Ratio : 1.00 Cost Ratio : 0.98 236 Effect to the Surrounding Environment Item Newly-constructed RC Newly-constructed SUS Replaced RC Structure Structure Steel Structure Noise & Vibration Maximum impact due to Minimum impact due to Medium impact due to long duration for shortest duration for short duration for demolition and field works demolition and site demolition and long welding execution duration for field works Slope & Ground Liquefaction of Slope Less impact is expected Less impact is expected during the construction is during the construction, during the construction, concerned because of and the impact is however, empty weight excavation to the negligible because empty gains and settling may foundation ground. weight saving was also occur. considered. Excellence and Deficit on Structural Type Evaluation Newly-constructed Newly-constructed Replaced RC Items RC Structure SUS Steel Structure Structure Reservoir’s Capacity ○ ○ ○ Seismicity ○ ○ ○ Water Tightness ○ ◎ ○ Corrosion Resistance ◎ ○ ◎ Durability ○ ○ ○ Maintenance △ ◎ △ Constraints of Construction ○ ◎ ○ Construction Period △ ◎ ○ Economy ○ ○ ◎ Effect to the Surrounding Environment ○ ◎ ○ Evaluation ○ ◎ ○ Adoption of Structural Type The renewal construction method by SUS Steel Structure was adopted in comparison with the above-mentioned construction methods. Adoption Reasons - Capacity reduction can be sufficiently covered by the shifting (alternating) of distributing area etc. - Construction costs for excavation, backfill and demolition can be reduced by retaining the bottom plates and side walls. In addition, the impact to the surrounding ground including the slope surface and impact by noise/vibration to the neighboring residences can be reduced during the construction period. - The stability of surrounding ground can be sustained into the future because the lightness of empty weight of distribution reservoir’s body. 237 - Problems can be easily verified because of the installation of maintenance space between the side wall and SUS reservoir. In addition, the prevention of runoff to the ground surface is possible because leakage can be stored in the said space in case of water leaks from the cistern. - It is excellent on the maintenance point of view because of small maintenance cost in spite of the most expensive construction price. In addition, it is also very excellent at water tightness. - Reservoir’s early utilization can be expected since this can be completed without constraints. Construction Overview to be Decided (see Fig. 8) Fig.8 Cross Section [Construction Overview] Specification on Reservoir made of Stainless Steel Plate Dimension ≤ 49,600 × ≤ 33,600 × > 4,944 (Available : 7,200 m3) Main Body Roof Plate SUS329J4L-1.5t Wall Material Using SUS329J4L for the range from HWL till -1.0m, Otherwise, use SUS316. Bottom Plate SUS316A-3.0t Annular Plate SUS316A-6.0t Flow uniforming baffle is based on the side plate. Step Inner (Inside of Tank) : 20A RB-φ16 SUS329J4L,SUS316 Inner (Outside of Tank) : 20A RB-φ16 SUS304 Outer : 20A RB-φ16 SUS304 Handrail Outer : 20A RB-φ16 SUS304 Passageway CKPL-3.0t SUS304 Receiving Table 49,140×33,140×100H SUS304 (Bolt Set) C-100×50×5 Flange Waterworks F (7.5K) Standard Product SUS329J4L,SUS316 (Plate Flange) Parts in water uses SUS lining (Material should like the plumbing material or over). Finishing SUS Welding Portion with Pickled Surface Structure Welded Structure Type Special Note Quakeproof : Level 2 (in case of 2nd type ground) Field Assembly Snow Cover 0.85 m (30 N/m2/cm) The pitch of roof is as designed greater than 1/50. The rectangular distribution reservoir with the stainless steel plate will be fabricated by complete welding within the old RC building frame after retaining some parts (bottom plate/side wall) of the existing distribution reservoir as an exterior frame. Concrete (t=400mm) will be poured as the foundation on the bottom plate, while RC will be placed on the bottom portion of the side wall, In addition, SUS329J4L which has excellent corrosion resistance will be used on the vapor portions, such as the roof and upper side 238 plate etc. to counteract condensation of chlorine within the cistern. On the other hand, SUS316 will be utilized for the portion of liquid phase without condensation to improve corrosion resistance and durability. Furthermore, the aging distribution main with low seismicity will no longer be used when the reservoir will be rehabilitated. Finally, the effluent pipes will be replaced by quakeproof pipes on the southern side to simultaneously mitigate the disaster risk caused by leakage etc. CONCLUSION The Authority faces a severe management condition where water demand is decreasing due to the change of population structure and population decrease caused by low fertility and aging. In addition, there is the conversion to the private water supply of commercial-scale utility customers. However, the authority should respond to the residents’ request for safe, stable, reliable drinking water any time and any place by performing the seismic diagnosis, additional strength/renewal for the deteriorated water supply facilities. Nejo Water Treatment Plant facilities continue to contribute to the development of Hachinohe City. The facilities are being rehabilitated and made more resistant to earthquakes. The efficiency and management rationalization can be smoothly carried out through the quakeproof design by integrating the water supply system of Hakusan Water Treatment Plant by way of “Scrap & Build” without continuous facility utilization. Moreover, the start of construction for the Nejo Distribution Reservoir was scheduled on September this year. The stainless steel structure is being recommended because it is economically feasible as it aims at the highest level and longest life span for the facility. The Authority was inaugurated by integrating ten water supply utilities in 1986. Many deteriorated facilities, however, still remain even if some of the facilities were abolished and/or merged. At present, a long-term planning on the restructuring of such facilities is being prepared for implementation in 2008. Accordingly, explaining the residents’ responsibility will be required to realize the planned targets and goals. 239 240 The Quakeproof Diagnosis of Waterworks Facilities in Yokohama City Hidehiko Aihara ABSTRACT Yokohama Waterworks Bureau made the quakeproof standard of bureau unification. This standard considers adaptability of diagnosis technique and economy of quakeproof reinforcement each in waterworks facility. And it reflects regionality [such as] ground characteristics of Yokohama City. ______Hidehiko Aihara, Manager of Engineering Supervision Division, Water Works Bureau, the City of Yokohama, 1852 Bukkou-cho, Hodogaya-ku, Yokohama, Japan 240-0044. 241 1. BASIC POLICY OF SEISMIC DIAGNOSIS In Japan, there is "Guideline for Aseismic Construction Methods of Waterworks Facilities, and Description -1997- Japan Water Works Association" (hereinafter referred to as "JWWA Guideline"). This guideline is the standard aseismic design for waterworks facilities. Each water utility should aseismic-design on the basis of this JWWA Guideline. Yokohama city is located in the South Kanto region where the seismicity is very active, and has undergone many massive earthquakes. In “Yokohama City Disaster Prevention Plan - Earthquake Countermeasures” which was established in 2005, the following three earthquakes are assumed: (1) Earthquake in the South Kanto area, (2) Yokohama Epicentral Earthquake and (3) Tokai Earthquake. Additionally, as a reference, Earthquake in Kannawa/Kouzu - Matsuda earthquake fault zone, Earthquake in Miura Peninsula fault zones and others are shown. The land forms of Yokohama are classified into the hilly area, the plateau/terrace, the low land and the reclaimed land, and according to these land forms and the geotechnical conditions, the earthquake motion changes - such as local amplification. Therefore, in the seismic diagnosis, the earthquake motion to be considered should be determined after comparing the earthquake motion based on these assumed earthquakes and the design earthquake motion in "JWWA Guideline". In the seismic diagnosis, it is necessary to understand the structure characteristics based on the completion drawings and the filed investigation. In addition, it is necessary not only to evaluate and understand the health of structure based on the survey of existing conditions but also to examine the history of repair and reinforcement of facilities and the locational conditions such as neighboring land form. The procedure of seismic diagnosis is basically the same as that of design of new facility. Considering the importance of facilities, the probability that secondary damage occurs when it is visited by an earthquake and others, Yokohama city decided to implement the seismic diagnosis based on the quantitative diagnosis calculation which is relevant to the secondary diagnosis in principle. The concept will be shown. 1 - 1 Input Earthquake Motion Used in The Seismic Diagnosis The relationship between an earthquake and earthquake motion is shown in Figure 1-1. The earthquake motion depends on the type of fault and its rupture condition (source characteristics), the propagation condition in the crust of the wave generated by the fault rupture (propagation path characteristics) and the condition of soil structure of the neighborhood of target point (site characteristics). Therefore, even if the same earthquake is assumed, the propagation path characteristics and the site characteristics are different, and accordingly the earthquake motion is different if the investigated point is different. Furthermore, it is usual to consider the earthquake motion including consideration of vibration characteristics of the structure. In the design earthquake motion defined in “JWWA Guideline,” the source characteristics and propagation path characteristics which are shown in Figure 1-1 are common throughout the nation, the design seismic coefficient and the velocity response spectrum according to the site characteristics and the vibration characteristics of the structure are defined. Vibration characteristics of aboveground structure Site characteristics Propagation path characteristics Source characteristics Figure 1-1 Characteristics of earthquake motion 242 On the other hand, in “Yokohama City Disaster Prevention Plan” different source characteristics (fault models) are assumed, and furthermore, the earthquake motion distribution (Instrumental seismic coefficient maximum acceleration/maximum velocity) on the ground surface of the whole city according to the propagation path characteristics and the site characteristics is calculated. In earthquake motion level 1, it is based on the design earthquake motion in “JWWA Guideline.” In earthquake motion level 2, basically the larger earthquake motion in the comparison between the design earthquake motion in “JWWA Guideline” and the earthquake motion of the earthquake which is assumed in “Yokohama city Disaster prevention plan” is adopted. And as for the design seismic coefficient which is used in the seismic coefficient method of aboveground structure, the above standard horizontal seismic coefficient Kh02 and the structure characterization factor Cs are considered as shown in Formula 1-1. This indicates that the structure is generally damaged and the absorption of energy due to the entry of member stiffness into the plastic field is expected. The value of Cs can be obtained based on the attenuation characteristics and plastic deformation capacity of structure as shown in Formula 1-2. ⋅= 2h KCsK 02h ····································································································································································(Formula 1-1) ⋅= h DDCs η ····································································································································································(Formula 1-2) Kh2: Design horizontal seismic coefficient which is used in earthquake motion level 2 Kh02: Standard horizontal seismic coefficient in the barycentric position of the structure Cs: Structure characteristic coefficient Dh: Correction coefficient according to the attenuation characteristic of the structure Dη: Response depression coefficient based on the plastic deformation capacity In the earthquake assumed in “Yokohama City Disaster Prevention Plan”, the earthquake source fault model is assumed. Each data of earthquake intensity, ground level maximum acceleration, ground level maximum velocity and liquefaction risk in the assumed earthquake is required in a distribution map by 50m mesh unit in the whole city. If the ground level maximum acceleration in the assumed earthquake exceeds the design horizontal seismic coefficient in “JWWA Guideline,” the input earthquake motion is set in the following method. (1) Design seismic coefficient which is used in the design based on the seismic coefficient method of aboveground structure As the ground level maximum acceleration is the value of acceleration on the ground, it is corrected to the response acceleration spectrum of structure based on Formula 1-3. K ×= h02 02 KK 2ShSh ···························································································································································· (Formula 1-3) K h2 K S02h : Design seismic coefficient which is used in the design based on the seismic coefficient method of aboveground structure in the assumed earthquake K S2h : Design horizontal seismic coefficient on the ground level in the assumed earthquake. The value obtained by dividing the ground level maximum acceleration by the gravity acceleration g (= 980Gal) K 02h : Standard horizontal seismic coefficient which is used in the design based on the seismic coefficient method of aboveground structure in “JWWA Guideline” K 2h : Design horizontal seismic coefficient on the ground level in “JWWA Guideline” (2) Design seismic coefficient which is used in the design based on the seismic coefficient method of underground structure The value (= Kh2S) which is obtained by dividing the value of ground level maximum acceleration by the gravity acceleration g (= 980Gal) may be used. As the embedment of underground structure is usually shallow, the ground level maximum acceleration is directly converted as seismic coefficient in the ground on the safe side. (3) Design earthquake motion which is used in the design based on the seismic deformation method of the underground structure The ground level maximum acceleration can be used as velocity response spectrum for design, Sv. In this case, as the ground level maximum velocity is calculated as response speed in which the response of 243 subsurface ground is considered, this value is directly used as Sv. As for the earthquake input which is used in the dynamic analysis, the value which is adapted to the design response spectrum of “JWWA Guideline” with using the past observation records, and the observation records and others in Southern Hyogo Prefecture Earthquake should be used basically. In Figure 1-2, the acceleration waveform which is adapted to the upper limit of earthquake motion Level 2 is shown as an example. The case that the observation record (Southern Hyogo Prefecture Earthquake Hukiai Y direction) is the original waveform: maximum 649.2 [gal] [gal] Amplitude Time [s] Figure 1-2 Example of ground level acceleration waveform of earthquake motion level 2 (upper limit) (adapted to the acceleration response spectrum [Type II Ground] in “JWWA Guideline”) In “Yokohama City Disaster Prevention Plan”, the ground level waveforms in 150 strong-earthquake observation points in the city are required. However, as the target facilities are not always located near the observation points, we decided to use the above adapted waveforms. And also, if the acceleration waveform in the assumed earthquake is created, based on the ground level acceleration waveform (adapted waveform and others) in “JWWA Guideline” shown in Figure 1-2, the amplitude of the waveform is uniformly increased. The amplification factor is the ratio between the ground level maximum acceleration in the assumed earthquake and that in “JWWA Guideline”, and it is used after correcting as shown in Formula 1-4. () ()×= K S2h &&&& tutsu ······························································································································································· (Formula 1-4) K 2h && ()tsu : Ground level acceleration waveform in the assumed earthquake && ()tu : Ground level acceleration waveform in “JWWA Guideline” (adapted waveform and others) : Ground level design horizontal seismic coefficient in the assumed earthquake. The value which is K S2h obtained by dividing the value of maximum ground acceleration by the gravity acceleration g (= 980Gal) K 2h : Ground level design horizontal seismic coefficient in “JWWA Guideline” 1 - 2 Aseismic Capacity of Facility Yokohama city sets the importance of facilities at Rank A, and the fundamentals of aseismic capacity of each structural site of the target facility is shown in Table Ⅰ. In earthquake motion level 1 (L1), the check based on so-called allowable stress method is mainly conducted, and in earthquake motion level 2 (L2), the aseismic capacity depends on the function of facility. As for the facility in which water-tightness is required and RC member in the bar arrangement where the toughness is not provided against bending, the aseismic capacity is one that the cross-section power is kept within the elastic limit (yield resistance) and the damage of member is not allowed basically. Therefore, the seismic calculation in earthquake motion level 2 of water tank structure and others may be basically implemented based on the linear analysis (elastic analysis). And as for the foundation, if it is judged that there is no problem in the stability of superstructure which the 244 foundation supports even if the generated cross-section power exceeds the maximum proof stress in earthquake motion level 2, the damage of the foundation can be allowed. TABLE Ⅰ FUNDAMENTALS OF ASEISMIC CAPACITY OF EACH STRUCTURAL SITE OF FACILITY Earthquake motion level L1 L2 Importance • The cross-section power which is • The cross-section power which is generated generated in the member should be kept in the member should be kept under the within the elastic limit, and the check is maximum proof stress. However, as for the conducted based on the allowable facility in which water-tightness is required and the member whose toughness is not stress. provided, the cross-section power which is • The response displacement of structure generated in the member should be kept and foundation should be under the within the elastic limit, and the check is design displacement. conducted based on yield resistance. Rank A • The stability of foundation should be • The response displacement and the residual within the given safety factor. displacement of structure and foundation • The stability of ground should be within should be under the limit value. the given safety factor. • As for the stability of foundation, the damage can be allowed if there is no problem in the stability of superstructure which the foundation supports. • The stability of ground should be within the given safety factor. 1 - 3 Items and Contents of Seismic Diagnosis The basic is to check the damage of members of each structure, the stability of foundation, and the displacement and deformation of structures. However, as for the structure (such as a tunnel) which is constructed in the mountain district and hilly district earth and in which earth covering is sufficiently deep, not the aseismic capacity of the main body but the influence of landslide on the opening has to be diagnosed. The contents of earthquake motion level 1 is basically the same as those of earthquake motion level 2. However, as for the superstructure in the aqueduct bridge, the water pipe bridge and the pipe in the slope, the diagnosis of earthquake motion level 1 is usually omitted. And if the liquefaction of the ground is concerned, the judgment of liquefaction and that of fluidization are implemented. Especially, as for the water tank structure and channel structure in a basement or a semibasement, the judgment of rise of skeleton and the examination of unequal settling are required. 2. SEISMIC CALCULATION METHOD In the seismic diagnosis, it is the principle to understand the focus in the earthquake resistance based on the structure of the target facility, the landform and the geotechnical condition, and use the analysis model and analysis method with which these can be expressed quantitatively. However, if the structure or the ground condition is special, it is necessary to apply the calculation method suitable for them. This time, we will explain the basin-like structure such as a distribution reservoir and others which are extremely important in Yokohama city. 2 - 1 Seismic Calculation of Basin-like Structure The procedure of seismic calculation of basin-like structure is shown in Figure 2-1. Most of the water utility is the basin-like structure and the types are various kinds. 245 START Seismic diagnosis of Seismic diagnosis of Level 1 earthquake motion Level 2 earthquake motion Yes Is the dynamic analysis required? Calculation based on the No seismic coefficient method Is only the seismic coefficient method No required? (Is the setting depth of the skeleton into the ground less than 10m?) Setting of design horizontal seismic Yes coefficient (Refer to 2.3 Input earthquake Setting of velocity response spectrum motion used in the seismic diagnosis) (Refer to Input earthquake motion used in the seismic diagnosis) Calculation of ground response displacement Yes Is the inter-story deflection angle 1/100 and below? Calculation based on the No seismic coefficient method Setting of velocity response spectrum The calculation based on the (Refer to Input earthquake motion used in seismic deformation method the seismic diagnosis) is also examined Judgment of liquefaction Judgment of liquefaction Yes Yes Calculation of seismic load To liquefy To liquefy (Earth pressure in the earthquake, No No Spherical surface shear force) Calculation of subsidence due to liquefaction Judgment of Reduction of the subgrade reaction skeleton rise coefficient of foundation which is used in the seismic coefficient method Check of the opening Setting of design load Setting of design load - Resistance against water - Resistance against water pressure in the earthquake pressure in the earthquake - Inertia force in the earthquake - Inertia force in the earthquake Yes Yes Is the stereo analysis required? Is the stereo analysis required? No No Calculation of cross- Calculation of cross- Calculation of cross- Calculation of cross- section power in the section power in the (Including the superposition with section power in the section power in the earthquake using earthquake using continuous cross-section power) earthquake using earthquake using 3-D model 2-D model 2-D model 3-D model Check of the allowable stress Check of the proof stress based on Check of the opening the limit state design method Check of the opening END Figure 2-1 Procedure of seismic calculation of basin-like structure 246 As it is impossible to analyze such various structures with one analysis method, in the seismic calculation in earthquake motion level 2, the structure whose setting depth is more than 10m (in the case of basement type, the height of skeleton is more than 10m) is considered to be greatly influenced by the ground displacement and we decided to implement the seismic calculation with the seismic deformation method in addition to the seismic coefficient method. Generally, as shown in Figure 2-2, as the basin-like structure such as a distribution reservoir is built near the surface of the earth, the relative displacement which contributes to the deformation of structure is small even if the ground displacement amplitude in the earthquake is great. Therefore, as for the structure whose setting depth into the ground is shallow, we decided to adopt the seismic coefficient method in which the inertia force is main as an analysis method. Distribution reservoir配水池等 and others Relative構造物の変形 displacement which に寄与する相対変位contributes to the deformation of structure Distribution地震時 of ground displacement地盤変位分布 in the earthquake 工学的基盤面Engineering bedrock surface Figure 2-2 Distribution of ground displacement in the earthquake which contributes to the deformation of structure The setting depth into the ground in this situation indicates the setting depth into the original ground which spreads planarity as shown in Figure 2-3, and the embedment into the part of cover soil of the underground structure in appearance due to cover soil and others and the structure which is set on the sectional terrace is not recognized as setting depth. Even if the setting depth into the ground is more than 10m, the influence by the ground displacement is regarded as small one and the calculation based on the seismic deformation method can be omitted if the inter-story deflection angle which is obtained based on the distribution of ground displacement as shown in Figure 2-4 is smaller than 1/100. 247 Distribution配水池等 reservoir Setting根入れ深さ depth Distribution配水池等 Setting根入れ深さ depth reservoir Sectional terrace surface 局所的な台地面 (no embedment) Cover soil 覆土 （根入れなし） Distribution 配水池等reservoir Distribution 配水池等reservoir Setting根入れ深さ depth Figure 2-3 Definition of setting depth ⊿U h ⊿U h Uh0:Uh 0Ground：上床版位置の displacement of the position地盤変位(m of upper floor ) slab (m) Df: Setting depthD f：構造物の of structure (m) (Height of skeleton) θ 根入れ深さ(m ) G （躯体高） UhUhB: Ground：下床版位置の displacement of the B position地盤変位(m of bottom floor ) slab (m) Relative displacement相対変位：⊿U h＝U h 0 －U h B 層間変形角 ：θ ＝⊿U h／D f Inter-story deflection angle G Figure 2-4 Calculation method of Inter-story deflection angle If the structure calculation is implemented, the typical cross-section is often extracted and 2-D framework model is created. Some real structures have the side wall (so-called in-plane wall) which runs parallel to the loading direction, some earthquake-resisting walls or training walls. If the existence of these walls is not considered, the diagnosis result on the safe side may be brought excessively. Therefore, it is necessary to create the appropriate analysis model such as stereo analysis model according to the selection method of analysis model which is shown in 2-2. 2 - 2 Selection of Analysis Model In the analysis model, the ability of accurate simulation of behavior in the earthquake of the structure is required. For example, as shown in Figure 2-5, in the case of a beam - column structure distribution reservoir, the main members of the skeleton of the distribution reservoir are side wall, beam, column, upper floor slab 248 and bottom floor slab. And the secondary member is training wall. And also, in a large-scale distribution reservoir, joints are set and the skeleton is divided into some blocks. Even in the distribution reservoir whose structure is relatively simple, there are many issues to be considered in setting the analysis model - for example, as to whether 2-D model in which the cross-section is simply extracted is proper. Sid側e 壁wa ll Beam, Co梁lu、m柱n Side 側wa壁ll Training導 w流a壁ll 目Jo地in t J目o地int 目 地 Joint J目o地int 目 地 J目o地int Figure 2-5 Example of constructional elements of distribution reservoir (Nogeyama new distribution reservoir) (Condition in which the upper floor slab is removed) In the 2-D model, modeling is easily conducted, but the existence of the in-plane wall is not easily considered. So, the deformation and cross-section power of the structure are often estimated excessively. And also, if the cross-section changes along the depth direction, each cross-section which changes should be modeled. Therefore, it is unfit for the analysis of the structure which has complicated shapes. On the other hand, in the 3-D model, basically, almost all types of structures can be easily modeled. However, modeling, accumulation of cross-section power and check of members require lots of efforts. The 3-D model should be applied basically. 2 - 3 Seismic Calculation Based on The Seismic Coefficient Method In the basin-like structure, the following load is considered as concrete load. a. Continuous load elements c Own weight of skeleton d Hydrostatic pressure due to internal water eLoad of covering of earth and sand f Hydrostatic pressure due to groundwater b. Load elements in the earthquake g Inertia force due to own weight of skeleton h Inertia force due to the load of covering of earth and sand i Active earth pressure in the earthquake j Dynamic water pressure in the earthquake due to internal water In the analysis model, it is popular to install the subgrade spring and to trigger the subgrade reaction on the bottom surface and the side wall of receiving side. If there is pile foundation, the two methods of modeling are used: the method to model by replacing the pile foundation with the spring and the method to model the pile itself. In the case of direct check of aseismic capacity of pile foundation, it is desirable to conduct it with using the latter one. (1) Inertia force caused by own weight of structure and others In the estimate of the inertia force caused by own weight of structure and load of covering, the response characteristics of structure, earth covering and others should be considered. In principle, it is the value 249 which is obtained by multiplying each weight by the design seismic coefficient. If the target facility exists in the ground, not only the earth pressure in the earthquake from the side but also the inertia force caused by covering of earth and sand should be handled as spherical surface frictional force. (2) Earth pressure in the earthquake If it assumes a great earthquake, in the ground near the underground structure, strength of the soil softens by the localization of the soil distortion. And, as a general rule, it applies the earth pressure in the earthquake (The corrected Monobe-Okabe method) that considered the influence of falling from the peak to the residual strength. (3) Dynamic water pressure and water surface movement in the earthquake The dynamic water pressure which is generated in the basin-like structure is classified into two types: the one that acts as inertia force and the one that acts due to the movement of free water surface. After calculating these, they are superposed on the continuous hydrostatic pressure. In the seismic diagnosis of the existing facility, it is thought that the application of regular operating water level as water level of internal water is rational. However, in the light of the future operation plan and others, in principle, two types of water level (H.W.L and L.W.L) as a target is analyzed. (4) Influence of liquefaction If the ground near the basin-like structure liquefies, it is necessary to reduce the subgrade reaction coefficient of pile foundation according to the degree of liquefaction. And also, if the liquefaction occurs, it is possible that the ground near revetments and the sloping ground are influenced by the lateral flow, and the skeleton may rise due to the increase of excess pore pressure. It is also necessary to investigate them. Additionally, the compression may occur after dissipation of the excess pore pressure in the liquefied layer. If unequal settling of skeleton in the spread foundation is expected, the examination of opening is required. 2 - 4 Seismic Calculation Based on The Seismic Deformation Method In the basin-like structure, the following is considered as concrete load. a. Continuous load elements c Own weight of skeleton d Hydrostatic pressure due to internal water eLoad of covering of earth and sand f Hydrostatic pressure due to groundwater g Earth pressure at rest (Active earth pressure) b. Load elements in the earthquake h Inertia force due to own weight of skeleton i Earth pressure in the earth j Spherical surface shear force k Dynamic water pressure in the earthquake due to internal water If there is pile foundation, the two methods of modeling are used: the method to model by replacing the pile foundation with the spring and the method to model the pile itself. In the case of direct check of aseismic capacity of pile foundation, it is desirable to conduct it with using the latter one. And in this case, the earth pressure in the earthquake should act to the end of pile. (1) Earth pressure in the earthquake In principle, the earth pressure in the earthquake is calculated based on Formula 2-1. And as for the earth pressure in the earthquake, continuous earth pressure element (earth pressure at rest and others) should be considered additionally because it is the load which is generated due to the influence of the earthquake. {}−⋅= hH zUzUkzp Bh )()()( ··············································································(Formula 2-1) 2 ⎡π ⋅ z ⎤ )( TSvzU ⋅⋅⋅= cos ··········································································· (Formula 2-2) h π 2 G ⎢ 2H ⎥ ⎣ ⎦ p(z): Earth pressure in the earthquake per unit area at the depth z(m) from the ground level (kN/m2) Uh(z): Ground displacement in the earthquake at the depth z(m) from the ground level (m) 3 kH: Subgrade spring constant in the earthquake per unit area (kN/m ) z: Depth from the ground level (m) zB: Depth from the ground level to the bottom of skeleton of structure (m) Sv: Velocity response spectrum on the bedrock surface (m/s) TG: Proper period of subsurface ground (s) H: Thickness of subsurface ground (m) (2) Spherical surface shear force in the earthquake In principle, the spherical surface shear force is calculated based on Formula 2-3. 250 G ⎡π ⋅ z ⎤ τ = i TSv ⋅⋅⋅ sin ··········································································· (Formula 2-3) π ⋅ H G ⎢ 2H ⎥ ⎣ ⎦ τ: Spherical surface shear force in the earthquake per unit area at the depth z(m) from the ground level (kN/m2) Sv: Velocity response spectrum on the bedrock surface (m/s) 2 Gi: Dynamic shear modulus of rigidity in the ith layer (kN/m ) (Convergence rigidity which is obtained based on the dynamic analysis of ground) 2 (=γi*VsDi /g) TG: Proper period of subsurface ground (s) z: Depth from the ground level (m) H: Thickness of subsurface ground (m) (3) Influence of liquefaction In the application of the seismic deformation method, the influence of ground liquefaction is not considered. Because the relationship between the decrease of ground rigidity in the liquefaction and the ground displacement is complicated and unambiguous determination is difficult. Therefore, the examination of the influence of liquefaction should be conducted based on the dynamic analysis with using the seismic coefficient method or the effective stress analysis. 2 - 5 Calculation of The Opening Referring to the past cases of seismic damage of distribution reservoirs and others, the damage in joint parts is outstanding and the number of that in the skeleton of structure is much smaller. This actual condition indicates that the joint part is a weak point in the basin-like structure. The typical deformation pattern of joint is shown in Figure 2-6. In fact, it is thought that, in addition to this, rotational component and torsion element add and they create a complicated deformation pattern. If adjacent skeleton blocks have the same behavior, the deformation of joints does not occur. So, in the past damage cases, it is thought that the damage occurred by the combination of complicated factors such as the difference of ground conditions, the relationship between the wavelength of seismic wave and the scale of skeleton, the influence of residual deformation due to ground deformation ( landslide, liquidation, unequal settling and others). However, we must say that it is difficult under the present situation to obtain the behavior in the earthquake of these complicated skeleton accurately and analytically. We can say that it is appropriate to obtain them with simple methods. (a) Stretching(a )伸 and 縮 shrinking (b)水平方向ずれ (c)鉛直方向ずれ (b) Horizontal shear (c) Vertical shear Figure 2-6 Typical deformation pattern of joint So, the possible method is as follows: Assuming that one skeleton block remains stationary, the horizontal displacement of another skeleton block is regarded as opening. The displacement of skeleton block is one 251 which is obtained based on the said aseismic analysis. As the aseismic analysis is basically implemented in the log side direction of the structure and the narrow side direction of that, the elasticity and the horizontal shear are checked based on the horizontal displacement. As for the vertical direction, if the rise of skeleton and the settlement of foundation ground which are caused by the liquefaction do not occur, there is no problem, and if the liquefaction occurs, it is desirable to examine the installation of flexible joint whose allowable deformation is great to be prepared for unforeseen circumstances. The subsidence after dissipation of the excess pore water pressure in the liquefied layer after the earthquake is 5% of the thickness of liquefied layer below the bottom of skeleton as shown in Formula 2-4. In the calculation of subsidence, it is important to understand the distribution condition of liquefied layers, so the collection of drilling data and geology profile of neighborhood and the understanding of relative positional relationship with the structure are required. ⋅= l 05.0 HS L ··········································································································(Formula 2-4) Here, Sl: Subsidence due to the liquefaction of skeleton (m) HL: Thickness of liquefied layer below the bottom of skeleton (m) 2 - 6 Check Method of Aseismic Capacity The check of aseismic capacity of basin-like structure should be conducted as shown in Table Ⅱ. The allowable deformation of joint is set after hearing with the manufacturer of used joint. As for the pile foundation, if it is judged that the damage in foundation does not cause the trouble in the safety of superstructure in earthquake motion level 2, the damage in foundation can be allowed. Table Ⅱ CHECK OF ASEISMIC CAPACITY OF ABOVEGROUND WATER TANK Part Check item Earthquake motion level 1 Earthquake motion level 2 Abstract Bending: Generated bending moment ≤ Damage of Generated stress ≤ Allowable stress Yielding bending moment Skeleton member Sear: (RC) Generated shear ≤ Shear capacity Deformation Generated deformation Generated deformation of joint ≤Allowable deformation ( Allowable deformation Side wall Circumferential direction: Prestressed concrete steel Damage Only side wall: ≤ Skeleton of Generated stress Generated stress Yielding stress (PC) member ( Allowable stress Side wall Vertical direction: Generated bending moment ≤ Ultimate bending moment Skeleton Damage of Generated stress ≤ Allowable stress Generated stress ≤ Yielding stress (Steel) member Vertical subgrade reaction ≤ Allowable vertical bearing capacity Direct Stability of Action position of resultant No conducted foundation foundation ≤ 1/3 of foundation breadth Shear force of bottom face ≤ Allowable shear resistance force Bending: Generated bending moment ≤ Damage of Ultimate bending moment Generated stress ≤ Allowable stress member Shear: ≤ Pile Generated shear force Shear foundation capacity Pile axial force Stability of ≤ Allowable bearing capacity Pile axial force ≤ Limit bearing force foundation Planned grade displacement of pile ≤ Allowable displacement 252 3. CONCLUSION As stated above, Yokohama city established its own seismic diagnosis criteria based on various guidelines and data based on “JWWA Guideline” for the existing water utility, and provides the seismic strengthening measures based on this concept. We are sure that, based on this seismic diagnosis criteria, by understanding the geology and topography in each area and the characteristics of potential earthquake in the harsh economic conditions, the seismic strengthening measures in which safety and cost effectiveness are considered sufficiently can be provided. 4. REFERENCES [1] 1997. Guideline for Aseismic Construction Methods of Waterworks Facilities, and Description.: Japan Water Works Association. [2] 2005. Yokohama City Disaster Prevention Plan - Earthquake Countermeasures.: Yokohama City Disaster Prevention Council. [3] 1998. Guideline for Design and Construction of Water Supply Prestressed Concrete Tank, and Description.: Japan Water Works Association. [4] 2006. Guideline of Countermeasures Against Earthquake for sewerage Facilities, and Description.: Japan Sewage Works Association. [5] 1996. Design Criteria for Container Structures, and Description.: Architectural Institute of Japan. [6] 2002 Specifications for Highway Bridges, and Description - Ⅴ Aseismic Design.: Japan Road Association. [7] 2002 Specifications for Highway Bridges, and Description – Ⅳ infrastructure.: Japan Road Association. [8] 1992 Guideline for Design and Construction of parking facilities, and Description.: Japan Road Association. [9] 2004 Guideline for Aseismic Design of Land Improvement Facilities.: Japanese Society of Irrigation. 253 254 The Santa Clara Valley Water District’s Infrastructure Reliability Program – Implementing Improvements for Seismic Response Crystal J. Yezman, P.E., David E. Hook, P.E. and M.ASCE, Carol Fredrickson and Richard L. Volpe, G.E. and F.ASCE ABSTRACT Past earthquake activity and potential for future earthquake events makes seismic improvements an essential part of the Santa Clara Valley Water District’s (district’s) planning efforts. The district completed the Water Infrastructure Reliability Project Report in 2005, which determined both the current reliability of its water supply infrastructure with regard to major and minor hazards events and enabled the district to appropriately select a portfolio of recommended improvements that balance reliability (level of service) with cost. This report details the seismic analysis, implementation, and emergency planning being done at the district under the Water Utility Enterprise and Infrastructure Reliability Program. The results from the largest modeled earthquake event, the 7.9ML earthquake on the San Andreas Fault, indicated that the district’s water supply system could experience up to a 60 day outage from an estimated 18 pipe breaks, 20 pipe leaks, and damage to water treatment plants and pump stations. Less severe earthquakes, flooding and regional power outages were shown to have less of an impact on the district, with outage times ranging from 1 to 45 days. Portfolio 2 (which includes Baseline and Portfolio 1 components) stood out as the superior option after re-running the reliability model and performing cost/benefit analysis. This recommendation led to funding for capital projects and forecasting for operational improvements. Portfolio 2 is estimated to cost $150 million and reduces the outage period for the San Andreas event down from 45-60 days to 7-14 days and for the Hayward and Calaveras events, down from 45 days to 1 day. The cornerstone of Portfolio 2 is the addition of groundwater wells to both sides of the treated water system. Stockpiling pipes and life safety projects were considered highest priority projects under Portfolio 2, along with emergency planning. Construction of district-owned wells on the west and east sides of the district’s treated water system, while an integral reliability component, requires significant coordination with district operations staff, stakeholders, and executive management. Therefore, these capital investments are considered long-term and are being moved forward under the Development Phase of the Infrastructure Reliability Program Santa Clara Valley Water District, 5750 Almaden Expressway, San Jose, CA, USA 95118-3614 Crystal J. Yezman, P.E., Senior Civil Engineer, Water Utility Operations Division David E. Hook, P.E and M.ASCE, Engineering Unit Manager, Infrastructure Planning Unit Carol Fredrickson, Emergency Support Unit Manager, Emergency Services Unit Richard L. Volpe, G.E. and F.ASCE, Senior Geotechnical Engineer, Infrastructure Planning Unit 255 The Santa Clara Valley Water District’s Infrastructure Reliability Program – Implementing Improvements for Seismic Response Crystal J. Yezman, P.E., David E. Hook, P.E. and M.ASCE, Carol Fredrickson and Richard L. Volpe, G.E. and F.ASCE BACKGROUND The Santa Clara Valley Water District (district) is the primary water resource agency for Santa Clara County (population 1.7 million) in California. It acts not only as the county’s water wholesaler, but also as its flood protection agency and environmental steward for its streams and creeks, underground aquifers and district-built reservoirs. Its wholesale Water Utility Enterprise (WUE) includes contracting for imported raw water from the delta of the Sacramento River through the State Water Project (the nation’s largest state-built water and power development, and conveyance system) and the Central Valley Project (a long-term U.S. Bureau of Reclamation endeavor to provide water and hydroelectric power for farms, protect residents and property from floods, improve the navigability of the Sacramento River, and develop water supplies for the cities and towns of the Central Valley). The WUE efforts include capturing and storing rainfall in 10 local reservoirs, recharging the county’s groundwater basins, transporting raw water by means of a network of large-diameter pipelines and three pump stations, producing treated water at three water treatment plants (current maximum capacity 222 MGD), delivering the treated water to retailers via pipelines to 27 wholesale turnouts, encouraging water conservation, and supporting water recycling. The ages of the facilities vary; some dams were built as early as the 1930s, and some pipelines and canals date from the 1950s. The first water treatment plant and pump station were built in the1960s. Recent earthquakes in the region include the 1957 Daly City earthquake on the San Andreas Fault (ML1 5.3); the Coyote Lake and Morgan Hill earthquakes of 1979 and 1984 on the Calaveras Fault (ML 5.9 and 6.1, respectively); the 1980 Livermore earthquake on the Greenville Fault (ML 5.8); and the 1989 Loma Prieta earthquake on the San Andreas Fault (ML 7.1) or a parallel subsidiary fault. Of these earthquakes, the strongest shaking and most damage resulted from the 1989 Loma Prieta earthquake. The 1989 earthquake ruptured on or southwest of the Santa Cruz Mountains segment of the San Andreas Fault and produced MMI VII effects2 per the Mercalli intensity scale in San Jose. The Rinconada Water Treatment Plant (RWTP) experienced 44 percent gravity acceleration in the 1989 Loma Prieta Earthquake. It suffered significant damage to the reactor/clarifier baffles in the three basins that were in use at the time (see Figure 1). Two of the four clarifier units were rendered unusable. A third unit was damaged; however, it was usable in combination with the fourth unit. The fourth unit was empty and was not affected by the sloshing that damaged the other three units. It survived with no damage. The District also experienced some pipeline damage in the 1989 earthquake. One major leak required repairs at the time, with 2 other pipe joints experiencing damage which did not cause leaks and was not detected until internal visual inspections occurred between 2004 and 2007. 1 ML (or sub L) is reference to the Local Magnitude and the original scale developed by Richter. It is based on intensity of shaking in the area immediately surrounding the earthquake. 2MMI VII effects include non-structural damage, very strong shaking, difficult to stand, felt by all; furniture broken; damage negligible in building of good design and construction; slight to moderate in well-built ordinary structures; considerable damage in poorly built or badly designed structures; some chimneys broken. noticed by persons driving motor cars. small slides and caving in along sand or gravel banks 256 Figure 1 - Inlet pipeline damaged on clarifier at RWTP during 1989 Loma Prieta Earthquake. Following on the heels of the federally mandated vulnerability assessment, the district launched the Water Infrastructure Reliability Project in 2002 to assess potential hazards, current baseline survivability and recommended improvements. Working collaboratively with its retailers and other stakeholders, the district developed level of service goals following a major seismic event, and packaged recommended projects into portfolios that could be evaluated for cost benefit as a factor of reduced outage times. This paper details some of the technical analysis that was completed for the project as well as the progress that has been achieved towards implementing the recommended improvements. WATER INFRASTRUCTURE RELIABILITY PROJECT REPORT The district initiated the Water Infrastructure Reliability Project Report (IRP Report) [1], to determine both the current reliability of its water supply infrastructure with regard to major and minor hazard events and to enable the district to appropriately balance reliability (level of service) with cost. Major components of the IRP Report included coordinating with stakeholder to develop “level of service” goals following a major hazard event, identification and quantification of hazards, modeling to determine impact, portfolio development, and cost benefit analysis. The level of service goal that was established for evaluating the baseline reliability of the district’s system became the ability to provide potable water service at average winter flow to a minimum of one turnout per retailer within seven days, with periodic one day interruptions for repairs. This goal was considered preliminary because the process was considered iterative until a balance was established between the final system reliability and an acceptable rate impact (program cost). Hazard identification included a multitude of potential hazards with the greatest impact stemming from flooding, regional power outage and earthquakes. Figure 2 shows an excerpt from potential hazard maps that were generated during the project. The hazard maps showed such hazards as susceptibility to settlement and spread from liquefaction, fault rupture, flooding damage, and landslides. Shaking from peak ground acceleration controlled the magnitude of impact for many hazards. Calculations for peak ground acceleration for modeled earthquake events took into account spatial relationships of each system component to potential epicenters and underlying soil type and groundwater interactions. 257 Figure 2 - Excerpt from Potential Hazard Maps Generated During the Infrastructure Reliability Project [2] 258 Once the effects were know, the team developed fragility factors for system components to determine the impacts. These fragilities were based on an evaluation of the facility’s or pipeline’s original design criteria and the associated intent of the seismic code in place at the time of design, the type of construction and materials, and the performance of similar types of construction in historic earthquakes. Performance of district facilities during the 1989 Loma Prieta Earthquake provided a baseline for fragilities, particularly for those located in the western region of the service area. Lastly, the fragilities were compared against those developed for HAZUS, a nationally-applicable, standardized earthquake loss modeling software program developed by the National Institute of Building Sciences (NIBS) for the Federal Emergency Management Agency (FEMA). Multiple earthquake events were modeled based on probability of occurrence. The probability to provide flow was predicted based on the affect of peak ground acceleration on each system component, which differed with geographical location to the epicenter and fragility of the component. Modeled earthquake events included a 7.9ML earthquake on the San Andreas Fault, a 6.67ML earthquake on the Southern Hayward Fault, and a 6.23ML earthquake on the Central Calaveras Fault. The results from the largest modeled earthquake event, the 7.9ML earthquake on the San Andreas Fault, indicated that the district’s water supply system could experience up to a 60 day outage from an estimated 18 pipe breaks, 20 pipe leaks, and damage to treatment plants and pump stations. Less severe earthquakes, flooding and regional power outages were shown to have less of an impact on the district, with outage times ranging from one to 45 days. Restoration times for repairs were based on stockpiled material, staff levels, contract availability, and time estimates for making repairs. If sufficient spare pipe and materials were available, however, the outage time for the San Andreas event could easily be brought down to 30 days with minimal investment, and outage time for the smaller hazard events down from a maximum of 45 days to 14 days. The project team developed reliability improvement projects (capital and operational projects, grouped into portfolios) to protect district staff, assets and the public from the results of these hazard events. The decision making process for determining the best portfolio began with setting level of service goals with district retail customer input, and included analysis of cost, benefit, social, environmental, and other key objectives The portfolios were designed to be cumulative, with no stranded assets. Below is a summary of some of the key objectives up to Portfolio 3. Additional Portfolios, beyond Portfolio 3, are not shown. Baseline Portfolio – Programmatic improvements and smaller system fixes that bring the District up to the assumed baseline level of performance after a hazard event by improving emergency preparedness and creating reliable material stockpiles (such as spare pipe) for response efforts. Portfolio 1 –Programmatic improvements and smaller fixes that will ensure life safety and allow the District to respond and communicate more efficiently after a hazard event. Portfolio 2 – Increase the reliability of the District system, with at least one reliable source of groundwater available from District-owned wells for an emergency period of up to two weeks. Portfolio 3 – Increase the redundancy of the District system, with at least two reliable sources of water available for each customer for an emergency period of up to two weeks. Cost benefit analysis stemmed from estimates of economic disruption from water loss. The amount of disruption varies according to the importance of water to a particular industry, as well as concurrent impacts due to loss of function of other utilities (power, gas, etc.), transportation, and damage to the particular facility from fire damage (exacerbated by loss of water supply). The IRP Report assumed that 55% of economic activity would cease in the event of lack of water. The 55% value is a blended average 259 over types of economic activity. For example, lacking water, refineries must shut down whereas an office building may continue to partially function. This reduction factor was consistent with prior studies by the Bay Area Economic Forum, ATC-25, and assumptions made by other water utilities (e.g. East Bay Municipal Utilities District). Portfolio 2 (includes the Baseline and Portfolio 1 components) stood out as the superior option after re-running the reliability model and performing cost/benefit analysis. This recommendation led to initial funding for capital projects and forecasting for operational improvements. Portfolio 2 is estimated to cost $150 million and reduces the outage period for the San Andreas event down from 45-60 days to 7-14 days and for the Hayward and Calaveras events, down from 45 days to 1 day. The cornerstone of Portfolio 2 is the addition of groundwater wells to both sides of the treated water system. The district is in the enviable position of having a large groundwater basin that can be used in the short term with a high level of reliability, until the transmission and treatment system can be restored. Portfolio 2 takes advantage of this reliability asset. With the analysis and planning stages complete, the Water Infrastructure Reliability Project has entered the Development Phase. The Development Phase coordinates stakeholder interests in finding opportunities to reduce costs, determine funding options, and prepare an implementation strategy to move the recommended projects into planning and design. IMPLEMENTING IMPROVEMENTS FOR SEISMIC RESPONSE As indicated earlier, modeling results from the IRP Report indicted that the district could be faced with up to 60 days of outage time resulting from a major earthquake on the San Andreas Fault. In response, a CEO interpretation was created for Board Policy E-2.1.2, the water supply is reliable to meet current demands, and was based on suggested baseline improvements that were presented in the IRP Report. The CEO interpretation reads [3]: By December 31, 2007, the District will be able to meet retailer agreed-upon preliminary level of service goals of providing current average winter day demands to at least one treated water turnout for each retailer, and promote public safety within 30 days for potable service and fewer days for non-potable service following a major catastrophe at a cost of $2 million for spare pipe Purchase requests for spare pipe and appurtenances were awarded in June 2007, with delivery of materials scheduled for the end of the year. By stockpiling this pipe, the district will be in a much better position to respond to pipe breaks following a major, unplanned, multiple outage, and regional event. The reduction in estimated outage time from stockpiling this material is a valuable investment; however, additional investments are recommended under Portfolio 2 to bring the outage time down further, from 30 days to 7-14 days for the San Andreas event. Below is a summary of the specific project recommendations for Portfolio 2 with 2005 cost estimates, which includes operation and maintenance costs as well as an inflation factor though a ten year project schedule. Check marks indicate which items are included in the district’s current funding forecast. It should be noted that current cost estimates have increased by up to 100% due to inflation, schedule for implementation, and increased construction costs. 260 Figure 3 - Implementation Progress for Recommended Improvements up to Portfolio 2 from the Water Infrastructure Reliability Project Report In addition to planning for the projects indicated in the funding forecast above, staff has engaged a consultant to provide planning, engineering and outreach services for the IRP Development Phase. The IRP Development Phase has been designed to develop a project implementation strategy for the remaining unfunded project recommendations by working collaboratively with project stakeholders to identify cost savings and financing opportunities with the greatest mutual benefit. The consultant will prepare a final report summarizing the project implementation plan and perform general public outreach in the form of an exploratory committee to disseminate project objectives and determine public opinion regarding preferred financing. A 2007 Community Awareness Survey conducted by the district for Santa Clara County showed that 84% are in favor (51% strongly and 33% somewhat) of infrastructure reliability improvements to reduce outage times to 7 days, even if they would have to pay $4.30 more a month (margin of error of +/- 3.5%). 261 OTHER SEISMIC IMPROVEMENT EFFORTS Dam Seismic Improvements The district is a responsible dam owner, committed to ensuring public safety and operational availability. One of the elements of a comprehensive Dam Safety Program is the completion of periodic studies. The 2005 Dam Safety Program Report by Senior Engineer Richard L. Volpe and co-authors included recommendations for a number of measures to deliver a state of the art Dam Safety Program; one of these is the completion of an updated seismic stability evaluation for all 11 district dams. The district has initiated a Phase 1 seismic stability evaluation (SSE) of the first 4 dams, including Almaden, Anderson, Calero and Guadalupe Dams. It’s been over 20 years since seismic stability evaluations were completed on three of these dams; a detailed dynamic stability analysis has never been completed for Anderson Dam. Following the destructive 1994 Northridge earthquake, there is new information about fault activity for similar buried thrust faults, new predictions for earthquake accelerations likely to occur, and new and more realistic analytical tools available to perform seismic stability analyses. These dams were selected for the first phase to address regulatory concerns. The results of the Phase 1 SSE are due in 2008, when we will know which if any of these 4 dams require a seismic retrofit. Capital improvement projects will be initiated to address deficiencies if needed after we receive the results. Updated seismic stability evaluations for the rest of the district dams are recommended as well but not yet budgeted and scheduled. As a result of these seismic concerns, the district has proactively decided to impose reservoir restrictions at three of the dams in order to significantly increase the freeboard to safely accommodate more room for earthquake-induced settlement of the crest should a major earthquake occur before appropriate seismic retrofits, if found to be needed, can be completed. Treatment Plant Operations Improvements In addition to the recommendations from the IRP Report, the district is working on several seismic improvement projects for increasing the structural integrity of treatment plant processes to improve the reliability of operations following a major seismic event. This includes upgrades to chemical tanks and retaining walls as well as retrofitting existing clarifier and filter basins during other planned construction for treatment processes improvements. All new construction or upgrades for these efforts are being designed to meet a designed seismic event as follows [4]. Applicable loading combinations for equipment and structures will be determined using the 2000 edition of the International Building Code or the current local governing building code, whichever is more stringent. • The recommended design level earthquake for the project is one with a 10 percent probability of being exceeded in 50 years (i.e., a return period of 475 years). • The peak horizontal ground acceleration (PHGA) for the design level earthquake is 0.67g. • The peak vertical ground acceleration (PVGA) for the design level earthquake is 0.67g. Specific upgrades that are planned for structures that were damaged at RWTP during the Loma Prieta earthquake include [5]: • Strengthening of the clarifier basins’ walls and base slab • Replacement of the clarifier mechanisms with units designed and installed according to the project’s seismic design criteria 262 • Strengthening of walls between filter basins and their adjacent galleries. Also, thickening of the floor to resist the walls’ seismic load. EMERGENCY RESPONSE PLANNING Office of Emergency Services The district maintains a full-time Office of Emergency Services (OES) to coordinate emergency response and recovery for the district. During any emergency, the district must continue its primary mission of providing clean, safe water and flood protection to the people of Santa Clara County. The district’s OES ensures that critical services are maintained and emergency response is centralized. To accomplish this, it operates a comprehensive program that includes multi-hazard emergency response planning, training and exercising, and the operation and maintenance of the district’s emergency operations center (EOC). The district’s EOC is a multi-stationed communications center that serves as the hub for district emergency response and recovery coordination. The EOC houses modern equipment to support situation analysis, decision-making, response prioritization, resource allocation, media relations and emergency communications. Communications to other agencies and jurisdictions are supported by two-way radios, satellite phones and wireless messaging systems. The district is currently working on a communication interoperability project, which will allow seamless voice and data interoperability between emergency responder agencies in Santa Clara County. Currently the district is working on complying with the Department of Homeland Security (DHS) presidential directives. DHS created the National Incident Management System (NIMS) as required under Homeland Security Presidential Directive (HSPD)-5 "Management of Domestic Incidents". NIMS provides the framework for organizations to work together to prepare for, protect against, respond to, and recover from the entire spectrum of all-hazards events. The NIMS system was developed using the California (CA) Standardized Emergency Management System (SEMS) model, which created a SEMS/NIMS integration program for agencies in CA, with several compliance dates for 2007. This integration is an all-inclusive emergency operations program and includes emergency plans, training, business continuity plan, public information system, interoperability communications and national response plans. The district’s Office of Emergency Services provides the leadership, expertise and support for collaborative disaster response and recovery operations using the SEMS/NIMS model. Post-Earthquake Dam Assessment Program Another element of the district’s comprehensive emergency response planning resides under the Dam Safety Program as the Post-Earthquake Dam Assessment Program (PEDAP). PEDAP is comprised of trained staff volunteers who self-initiate dam assessments after a magnitude 5.0 or greater earthquake within 20 miles of one of our dams. Rather than waiting to hear exactly what magnitude of earthquake has occurred, volunteers are encouraged to self activate for their inspection if they have felt strong shaking for at least 10 seconds or longer. Organizing, training and deploying a team for these kind of critical yet somewhat rare events is a challenge. Our dam safety experts manage this team. These experts will mobilize to the district’s EOC if the event is significant enough, or manage the information gathering from their offices for smaller events. Due to the fact that these events do not happen that often, we have chosen to staff this under an internal “volunteer fire department” model. The team is overstaffed by about a factor of 3, to account for the unpredictability of who might actually be available when an event happens at a 263 time that is inconvenient – say, on a holiday weekend when it’s raining. The volunteers are provided with both a binder with information on all the dams and what to look for, and a kit of resources is located at each dam for their use. They are nominally trained to inspect a specific dam, but are expected to be able to inspect any of our 11 dams if needed. Communications and “command and control” remains a concern – communications and travel in large earthquakes is problematic, and we are still working on how to best communicate with them in the context of ensuring the dams are all covered, finding out what they know, confirming their status and location, etc. For a modest cost, the district has installed repeater boosters at all dams with poor radio signals that has significantly improved critical communication requirements during emergencies. Emergency Pipeline Repair/Response Training Another component of the district’s emergency response planning is the training and development of pipeline repair and response teams. Bi-annual workshops are planned and teams identified, including staff from maintenance, engineering, and project management. Their roles and responsibilities include post-event inspections and management of contract labor for repairs. The district is creating comprehensive guidelines that detail stockpiled pipe inventories and engineering specifications for making repairs under various repair situations and pipeline materials. At the workshops staff will be updated on administrative policy for contracting under emergency declarations and engaged in mock demonstrations. A GIS system has been created which ties into ground level photographs of vault locations and equipment numbers. The equipment numbers assist work order processing in Maximo and obtaining equipment specifications via the district’s Asset Management Database. Lastly, the emergency pipeline repair and response teams report into the EOC SIMS/NIMS model for situation control. CONCLUSIONS The district is fully committed to implementing recommended improvements for seismic response under the Infrastructure Reliability Program. This program follows the recommendations from the IRP Report, which was based on expert technical analyses as well as coordination with stakeholders. Implementation of the IRP Report recommendations will be one of the district’s most significant programs over the next decade and will require significant scheduling and coordination. The cost of Portfolio 2 (including operation and maintenance costs and inflation) is estimated to be $150 million, which is in the middle range of what other west coast utilities have recently spent on seismic and reliability improvements. Portfolio 2 is the project team recommended portfolio because: 1. It provides the greatest benefit cost ratio of all the portfolios. 2. It provides a level of service close to the level of service goals originally established for the project. 3. It reduces the outage period for “other events” significantly to one day or less. 4. It provides a reasonable balance of cost versus improved system reliability. 5. It provides significant opportunities for re-operation of the groundwater, raw water and treated water systems. 6. It provides significant operational flexibility to perform required maintenance while minimizing scheduled outages. 7. It results in less construction-related environmental impact than higher portfolios. 264 Stockpiling pipes and life safety projects under Portfolio 2 were considered the highest priority, along with emergency planning. Construction of district-owned wells on the west and east side of the district’s treated water system, while an integral reliability component, requires significant coordination with district operations staff, stakeholders, and executive management. Therefore, the well field capital investments are considered long-term and are being moved forward under the Development Phase of the Infrastructure Reliability Program. Additional seismic work and emergency response planning that is being done at the district outside Portfolio 2 project components include the Dam Safety Program, EOC coordination under the Office of Emergency Services, development of pipeline repair and response teams, and capital projects for seismic upgrade of treatment plant processes. 265 ACKNOWLEDGMENTS Santa Clara Valley Water District Board of Directors Rosemary Kamei, District 1; Joe Judge, District 2; Richard P. Santos, District 3; Larry Wilson, District 4; Patrick S. Kwok, District 5; Tony Estremera, At Large; and Sig Sanchez, At Large. Preparation of the IRP Report would not have been possible without the considerable contribution of many key individuals and agencies, including the following: Santa Clara Valley Water District David Hook, Crystal Yezman, Sandy Oblonsky, Heinz Haase, Ray Yep, Water Infrastructure Reliability Technical Team, and Operations and Maintenance Staff. District Retailer Stakeholders California Water Service Company, City of Cupertino, City of Gilroy, City of Milpitas, City of Morgan Hill, City of Mountain View, City of San Jose, City of Santa Clara, City of Sunnyvale, Great Oaks Water Company, and San Jose Water Company. Other Stakeholders Alameda County Water District, Bay Area Water Supply and Conservation Agency, California Department of Water Resources, City of Palo Alto, Pajaro Valley Water Management Agency, San Benito County Water District, San Francisco Public Utilities Commission, United State Bureau of Reclamation, and Zone 7 Water Agency. Professional Consultants RMC Water and Environment, ABSG Consulting, Geomatrix Consultants, Inc., and GE Engineering Systems, Inc. REFERENCES [1] Santa Clara Valley Water District. 2005. Water Infrastructure Reliability Project Report. Santa Clara Valley Water District, San Jose, CA. [2] Traubenik, M.L and T. Crampton, Geomatrix Consultants, 2004 “Geologic and Geotechnical Hazard Assessment for the Santa Clara Valley Water District Reliability Report”, Vol 2. Water Infrastructure Reliability Project Report, Santa Clara Valley Water District, San Jose, CA [3} Santa Clara Valley Water District. 2007 “V. CEO Interpretations, ” Governance Policies of the Board of Directors, Santa Clara Valley Water District, San Jose, CA, pp. V-3. [4] Camp, Dresser & McKee Inc, 2000 “Final Technical Memorandum 3.11 Structural and Seismic Design Criteria”, Water Infrastructure Improvement Project, Phase 11, Santa Clara Valley Water District, San Jose, CA. [5] EQE International, 1995 “Seismic Evaluation of Existing Structures Technical Memorandum”, prepared under Task 9.4 of the Water Quality Regulation Compliance Project (WQRCP). Santa Clara Valley Water District, San Jose, CA. 266 5th AWWARF/JWWA Water System Seismic Conference SESSION 5 Earthquake Studies and Evaluations Prof. Masanobu Shinozuka, University of California, Irvine, US – “A Sensor Network for Real-Time Damage Location and Assessment” Mr. Munetaka Abe, Japan Water Works Association, Tokyo, JAPAN – “Damages to Water Supply Facilities by the Noto Peninsula Earthquake in 2007 and Restoration Works and Issues” Mr. Jianping Hu, Los Angeles Department of Water and Power, Los Angeles, CA, US – “Seismic Performance Evaluation of LADWP Water Supply System Using GIRAFFE” Dr. Gee-Yu Liu, National Center for Research on Earthquake Engineering, TAIWAN – “Seismic Repair Rate Analysis and Risk Assessment of Water Pipelines” Mr. Kuniaki Nakamura, Fukuoka City Waterworks Bureau, Fukuoka, JAPAN – “Emergency Measures - A Study of the Fukuoka West Offshore Earthquake” 267 268 A Sensor Network for Real-Time Damage Location and Assessment Masanobu Shinozuka, Chulsung Park, Pai H. Chou and Yoshio Fukuda ABSTRACT This paper is a slightly modified version of a paper under the same title and by the same authors, which was presented at the Third International Workshop on Advanced Smart Materials and Smart Structures Technology, May, 29 and 30, 2006, Lake Tahoe, USA. This modified version is presented here for the purpose of information and discussion. This study demonstrates a sensor-based real-time monitoring and condition assessment system for urban lifeline infrastructure. Rapid detection of damage caused by natural and manmade hazards enables an efficient and effective emergency response minimizing human and property losses as well as societal disruption. In this paper, focusing on water supply networks, we will demonstrate a monitoring system consisting of a wireless network of power-efficient sensors for a rapid identification of the extent and location of pipe damage immediately after a disastrous event. The highlight of this paper lies in taking advantage of sharply transient change in hydraulic parameters such as the water head due to the damage, and in verifying the simulation result by experiments. The result suggests that a simple inverse analysis can locate the damage in a pipe segment between two neighboring sensors among the pervasively installed along a pipe at which the absolute values of water head are observed to be local maxima. Separate experiment and analysis show that the sharp transient change in water head in the pipe flow induces a correspondingly sharp change in the acceleration of pipe vibration. This fact is used for damage identification in this study. Masanobu Shinozuka, Distinguished Professor and Chair, Department of Civil and Environmental Engineering, University of California, Irvine, Irvine, CA 92612 Chulsung Park, Graduate Student, Department of Electrical Engineering and Computer Science, University of California, Irvine, Irvine, CA 92612 Pai H. Chou, Assistant Professor, Department of Electrical Engineering and Computer Science, University of California, Irvine, Irvine, CA 92612 Yoshio Fukuda, Researcher, Department of Civil and Environmental Engineering, University of California, Irvine, Irvine, CA 92612 1 269 INTRODUCTION Urban water delivery network systems, particularly the underground components such as pipeline networks, can be damaged due to earthquake, pipe corrosion, severely cold weather, heavy traffic load on the ground surface, and many other man-made or natural hazards. In all these situations, the damage can be disastrous: water leakage at high pressure may threaten the safety of near-by buildings due to scouring of their foundations; flooding could create major traffic congestion if pipe ruptures under a busy street; and above all, after a severe earthquake, pipe damage may result in reduction in the water head, degrading post-earthquake firefighting capability of the community, while at the same time force the human consumption of water to drop below unacceptably low level. Yet, the current technology is not capable of accurately identifying the location and extent of the damage easily or quickly, especially immediately after a major earthquake. As a result, even if full resources are available for damage repair, failure to locate damage can still lead to loss of post-earthquake firefighting capability, widespread human suffering and outbreak of diseases after a major earthquake. This paper summarizes most recent papers by the authors ([1], [2] and [3]) and demonstrates potential use of a sensor network for identification of location and extent of damage in real-time. DAMAGE DETECTION AND LOCALIZATION OF PIPE NETWORK Hydraulic Transients A hydraulic transient represents a temporary, often violent, change in flow, pressure, and other hydraulic conditions in a water delivery system from an original (first) steady state to a final (second) steady state the system achieves after the effect of the disturbance that caused such a transient is absorbed into the second state. The disturbance includes such events as a valve closure or opening, a pump stopping or restarting depending on power supply, and pipe damage or break leading to water leakage. The transient can produce a significant change in water head and pipe pressure. In fact, as described in more detail in what follows, it is envisioned that the sudden change of such pressure will generate a measurable pressure wave and can be used for detection and localization of pipe damage. If the magnitude of this transient pressure is beyond the resistant capacity of system components, it can induce disastrous effects on the water system. Therefore, it is important to simulate the transient behavior of the water system under various adverse scenarios in order to understand the magnitude of these effects. In this study, the industry-grade computer code HAMMER (Haesead 2003) is employed to generate time histories of key hydraulic parameters (primarily water head and flow rate). The analysis is carried out for a hydraulic system as shown in Figure 1 which appears in HAMMER User’s Guide. This water system consists of two reservoirs, one pump, one valve, thirty-eight nodes and fifty four pipe links. In the following, we consider a case in which a pipebreak occurs at the mid point of link 111. In this case, a new node can be added in this link (double circle in Figure 1), and the numerical analysis continues. For another case in which pump station stops, waterhead transient behavior is quite dramatically time variant as shown in Figure 2. Appropriate physical parameters of nodes and pipes are used for the analysis [1]. 2 270 Figure 1. Distribution of water head gradient due to pipe P111 break (a) J9 (b) J11 (c)J13 (d) J20 Figure 2. Nodal water head time histories under event scenario 2 (pump stops) Damage Detection A method of damage detection and localization, including the identification of malfunctioned equipment, is described here that is based on the comparison of the hydraulic parameters (the water head in this case) before and after the event. For the primary purpose of a rapid detection and 3 271 localization, it is most effective to catch the sign of change at the outset of the event. Fortunately for a sudden change such as a pipe break and pump stoppage, the response of the network is rapid particularly in the neighborhood of the source. This suggests that some measurable signature that indicates the rapidity of this change can be used for this purpose. One convenient quantity that serves this purpose is the water head gradient as defined below. − HH D = 12 (1) − tt 12 Here H2 and H1 are the water head of a node at the time t2, t1 respectively and t2-t1=0.2 second in this study. During the steady state normal operation, D is usually negligibly small. In this paper, the water head gradient measured at the observation nodes are integrated into the GIS platform for real-time visualization and for other advantages. Figure 1 shows the water head gradient distribution in a contour plot in extended network space for the convenience of visualization. The contour plot indicates that the damage location can be identified to be in Pipe 111 between nodes J9 and J11 where water head gradients are locally maximum. PROPOSED DAMAGE INDENTIFICATION METHODOLOGY Non-Invasive Detection In this section, a damage identification method based on wireless MEMS-sensor network is proposed which is different from the Water Head Gradient-Based approach mentioned above in that the proposed method measures the acceleration change at pipe surface and therefore it is not invasive. To accurately locate the damage at a reasonable cost over a vast lifeline network, we must, however, support adjustable monitoring granularity through trade-offs among deployment density, sensor accuracy, wireless communication range, and costs. Real-Time Monitoring Increasing demand for rapid damage detection and assessment necessitates real-time monitoring capabilities. Real-time monitoring poses many challenges to designing sensor nodes, including fast communication links, fair and efficient media access protocols (MAC), and low-latency routing protocols. In our monitoring system, we use two different wireless interfaces. For short range communication, the Eco node uses a 2.4GHz custom radio with a data rate of 1Mbps. For longer range communication, DuraNode uses the 802.11b WiFi interface, whose maximum data rate is 11Mbps. Also, Eco and DuraNode use Time Division Multiple Access (TDMA) and 802.11b MAC, respectively, as their MAC protocol. Comparing with other wireless sensor platforms such as MICA2, Telos, and Stargate, Eco and DuraNode have higher or equivalent radio performance of in terms of maximum bit rate and radio range when used with the proper antenna. WIRELESS SENSOR NODES DESIGN 4 272 Both Eco and DuraNode can support the proposed real-time monitoring damage localization methodology. Although both of them can collect tri-axial acceleration data and transmit wirelessly, they are totally different platforms with complementary features, as shown in TABLE I. Eco is ultra-compact, low power, low cost, and is suitable for dense deployment with a short wireless range. In contrast, DuraNode is equipped with three high-end, high-accuracy accelerometers and a long range wireless interface (802.11b), in addition to the same type of radio as Eco. At the same time, DuraNode consumes over ten times the power as Eco. We take advantage of their characteristics and deploy a mix of these two types of sensor nodes by adapting the choice to the specific requirements on the spatial granularity of the water delivery network. Two sensor nodes can communicate each other via the available 2.4GHz wireless radio or RS232 serial interface. This combination is expected to make the proposed real-time monitoring methodology accurate and cost effective. For the detail, see Shinozuka et al., 2006. TABLE I. COMPARISON OF ECO AND DURANODE Eco DuraNode Size (mm) 13 x 11 x 8 140 x 80 x 20 Sensor One H34C Three SD1221, Gyroscope Power Consumption Max. 100 Max. 1000 Max. Air Data Rate (bps) 1M 11M Battery 30mAh Li-Polymer 4000mAh Li-Ion Wired Interface Serial, SPI Fast Ethernet, Optical Wireless Interface 2.4GHz Custom Radio WiFi / 2.4GHz Radio Radio Range (m) 10 ~ 20 200 ~ 300 Cost ($) @ 1000 50 400 DuraNode (a) Top View (b) Side View Figure 3. Photos of DuraNode Figure 3 shows the picture of the DuraNode hardware. It consists of two boards: main board and daughter board. The main board has everything a wireless sensor node may need, including microcontrollers, sensors, and a wireless communication interface. On the other hand, the daughter board, as shown in Figure 3(b), has only a microcontroller but two wired communication interfaces, namely Fast (10/100 Mbps) Ethernet and Optical. Another daughter card can provide the wireless link to a short-range network of Eco nodes. In addition, DuraNode can also use both wired and wireless interfaces in dual mode. 5 273 Eco The Eco sensor node shown in Figure 4 consists of four subsystems:MCU/Radio, Sensors, Power, and expansion port. (a) On the finger (b) Side View (c) Top View Figure 4. Photos of Eco Sensor Node PRELIMINARY EXPERIMENTS To show the effectiveness of our MEMS sensor-based real-time monitoring system, we set up a small water delivery network using 1-inch diameter PVC pipes. We installed four DuraNodes onto the network and collected vibration data in real-time. This section describes the details of our experimental setup and presents the 3-axial vibration data collected under two different levels of water pressure. Experimental Setup The water delivery network consists of seven pieces of 62-inch PCV pipes (with a 1-inch diameter), one PCV pipe cap, and one valve. As shown in Figure 5 (b), we construct a rectangular-like pipe network, whose lengths on the two sides are 124 inches and 62 inches. Also, one valve is installed in the middle of the network (marked as VALVE in Figure 5b) and one Cap (marked as CAP in the same figure) on the top-left corner of the network. The VALVE and CAP function as possible damage locations in the pipe network. We can increase the water pressure inside the pipe network by injecting water at WATER INPUT in the experiment. At low water pressure, the VALVE remains closed as it initially is. This status represents ``No Damage in the Network.'' However, when the pressure increases so that it is high enough to force the VALVE open, the pipe between nodes A and B is network can be considered ``Damaged.'' In this experiment, CAP is kept closed throughout. Four DuraNodes are installed onto the pipe network, as shown in Figure 5b. They keep transmitting 3-axial vibration data to a host computer via an access point in real-time. The sampling rate is set to 1KHz. The CAP is used to vary the overall water pressure inside the pipe network. By manually setting to three different states, (CLOSE, HALF-OPEN, OPEN), we can adjust the maximum water pressure inside the pipe network (HIGH, MEDIUM, LOW). 6 274 CAP Node A Node D DuraNode 31” DuraNode 62” 62” Valve DuraNode x 62” 62” DuraNode Water Pipe 9.5” Node C Network Node B Water Input Diameter of the pipe: 1” (a) Photo of Water Pipe Network. (b) Dimension of Water Pipe Network and locations where 4 DuraNodes are installed. Figure 5. Experimental Setup Results The results are 3-axial vibration data from four DuraNodes. Recording of the data begins when we start injecting water to the pipe network, and stop after a few tens of second when the VALVE is forced to open. Also, we repeat the same experiment at various levels of water pressure (HIGH, MEDIUM, LOW). In this section, we present only the X-axis vibration data in the high pressure condition (Figure 5). Each graph in Figure 6 shows the vibration data from each of the four DuraNodes labeled A, B, C, and D. The sudden change of vibration in each graph is developed when the VALVE is forced open by increasing water pressure. Upon closer examination of Figure 6, we find that the amplitude of each peak is different: Nodes A, B, C, and D have amplitudes of 0.5g, 0.28g, 0.35g, and 0.75g, respectively. These differences can be used to locate the damage in the pipe network. This result shows that the sharp change in acceleration is recorded in real-time by all the four DuraNode and transmitted to host computer at the same time. It is important to note that the accelerations recorded before and after the opening of the valve is not only constant but also identical in this case. This verifies that change in the water pressure due to damage can be identified by the change in acceleration on the pipe surface not invasively. Having mentioned this, however, we are yet to find the way in which the observed values of amplitude of change in acceleration can identify the damage location. 0.28g (b) 7 275 0.75g Figure 6. Acceleration Data of 4 DuraNode under High Pressure CONCLUSION AND FUTURE WORK Obviously, some more experiments must be carried out under more well equipped laboratory conditions for quantified detection of damage location. In addition, future work includes field experiments on a water network that is more realistic in scale than the one tested in the preliminary experiments described here. We plan to install Ecos and DuraNodes on a subset of a regimal water supply network such as City of Westminster and Irvine Water Ranch District systems. This will be done in conjunction with their existing SCADA measurement locations as available. The main technical challenge will be to install these sensor nodes on the pipe surface. Observing that there are a large number of hydrants in these systems, it appears best to install them on the pipe at the hydrant locations. ACKNOWLEDGMENTS This study was done under National Science Foundation Grant # CMS 0509018 and Grant # CMS 0112665. Their supports are immensely appreciated. REFERENCES [1] Shinozuka, M. and Dong, X. 2005a. “Evaluation of Hydraulic Transients and Damage Detection in Water System under a Disaster Event”, The 3rd US-Japan Workshop on Water System Seismic Practices, Kobe, January. [2] Shnozuka, M. and Dong, X. 2005b. “Damage Detection and Localization for Water Delivery Systems” Proceeding of the 5th International Workshop on Structural Health Monitoring, Stanford University, Stanford, CA, September, pp. 1267-1273. [3] Shinozuka, M., Park, C., Chou, P. and Fukuda, Y. 2006. “Real-Time damage localization by means of MEMS sensors and use of wireless data transmission,” in Proceedings of SPIE Conference on Smart Structures & Materials/NDE, San Diego, CA, February. [4] Park, C. and Chou, P.H. 2006. “Eco: Ultra-Wearable and Expandable Wireless Sensor Platform,” Proc. Third International Workshop on Body Sensor Networks, April. [5] Park, C. Chou, P.H. and Shinozuka, M. 2005. “DuraNode: Wireless Networked Sensor for Structural Health Monitoring,” to appear in Proceedings of The 4th IEEE International Conference on Sens, Irvine, CA, October. 8 276 DAMAGES TO WATER SUPPLY FACILITIES BY THE NOTO PENINSULA EARTHQUAKE IN 2007 AND RESTORATION WORKS AND ISSUES Munetaka ABE ABSTRACT In Japan, there were many big earthquakes over a past decade. The nearest disaster was the Noto peninsula earthquake occurred in April 25 th, 2007. The seismic scale was the Mg.6.9 and it damaged the infrastructure and houses of 3 cities and 4 towns. One person died and about 550 people were injured. The Noto peninsula, in the Ishikawa prefecture, is facing to the Japan Sea at the middle of Japanese archipelago. This area has many sightseeing places. But on the other hand, this areas has been rapidly losing population like other rural areas of Japan. The Ministry of Health, Labor and Welfare organized the survey team composed of various experts including JWWA staffs to investigate the damages and how to make recovery using many other aids. This paper takes up countermeasures against the seismic disaster occurred in the non-urban area referring to this Noto Peninsula earthquake. Fig .1 A map of Noto peninsula in Japan Wajima City Anamizu Town Shika Town Nanao City Munetaka Abe, Assistant Chief of Engineering Division, Japan Water Works Association 4-8-9, Kudan Minami, Chiyoda-Ku, Tokyo 102-0074 277 1. AN ABSTRACT OF SEISMIC INTENSITY 1.1 General condition of earthquake At 9:32 a m. on March 25th 2007, A big earthquake occurred in 11km deep in the offshore of Noto peninsula. This earthquake was over Mg.6 in Nanao, Wajima city and Anamizu town, and observed a little under Mg.6 in Shiga, Nakanoto and Noto town. Fig. 2 shows them. This earthquake was named “Heisei 19 year (2007) Noto peninsula earthquake.” Fig. 3 shows the distribution of after shocks occurred in a period of March 25th to April 3rd. After shocks were distributed in the rectangular zone which was shaped with about 40 km length and 15km width and it was inclined by about 60 degree from the horizontal surface. Fig. 4 shows the seismic activities of this time and the past. This earthquake was not so active like the Niigata Earthquake occurred in 2004 and was changing with the level of a little under the Fukui Earthquake occurred in 1948. Table 1 shows seismic intensity and maximum acceleration which were observed at the places where the intensity level was bigger than 5. These observation values are based on The Meteorological Agency Monthly Report. The maximum acceleration was composed value of three components for the different direction. In the places where the seismic intensity over 6 was observed, both of seismic intensity and maximum acceleration tends to be large. At observation point in Wajima (JMA Wajima), the maximum acceleration was relatively small in spite of the seismic intensity observed. At Wajima points, this suggested that a tremor of longer cycle was stronger than that of short cycle which was distinguished in a acceleration. A professor of Kanazawa University, Dr. Miyajima said about the seismic character of Noto Earthquake as follows. They take notice of the earthquakes in the boundaries of crustal plates in the Pacific Ocean and active faults of inland in Japan. But I could assume this earthquake occurred at active faults in the ocean floor. So in this meaning, we were taken aback by this happening. We could know that there were some causes that a seismic intensity and frequency characteristics at the observation points, which are only 500m or 1km away each other, were remarkably different. So it became clear that the local ground condition had a large influence on the earth tremor. 278 Fig. 2 A center of earthquake and distribution of Seismic intensity WAJIMA MONZEN ANAMIZU CENTER OF EARTHQUAKE Seismic intensity NANAO ● 6 over ▲ 6 under ▼ 5 over ■ 5 under Fig. 3 The distribution of after shocks 25 March 2007 - 3 April 2007 Fig. 4 The comparison of number of after shocks 9:00A.M. 4 April 2007, Present Mikawa EQ (M6.8) 1945 Niigata Pref. EQ (M6.8) 2004 South Hyogo Pref. EQ (M7.3) 1995 Count Number Fukui EQ (M7.1) 1948 Noto Peninsula EQ (M6.9) 2007 East Tottori Pref. EQ (M7.3) 2000 Fukuoka Pref. East Offing EQ (M7.0) 2005 Noto Peninsula EQ (M6.6) 1993 (days) 279 Table 1 Seismic intensity and max acceleration measured at several point (*measured by Prefecture) Seismic Seismic intensity Max acceleration Observation point intensity measured (cm/s/s) Wajima city, Monzen town 6.4 1304 K-NETAnamizu (ISK005) 6.3 901 6 over Nnao city, Tazuruhama town* 6.2 746 JMA Wajima 6.1 474 K-NET Fugi (ISK006) 5.9 945 Nakanoto town, Notobushita* 5.7 352 JMA Shiga 5.6 544 JMA Noto 5.6 278 K-NET Wajima (ISK003) 5.5 548 6 under Shiga town, sueyoshisenko* 5.5 274 Nakanoto town, suezaka* 5.5 331 Noto town, matunami* 5.5 555 K-NET Nouto (ISK004) 5.5 666 KiK-net Yanagida (ISKH02) 5.5 380 JMA Nanao oartly 5.3 258 K-NET Nanao (ISK007) 5.2 221 5 over K-NET Shoin (ISK002) 5.1 183 KiK-net Tamasu (ISKH01) 5.1 360 1.2 The general condition of damages Table 2 shows the human sufferings according to the Ishikawa prefecture government in June, one person died and 341 peoples were slightly or seriously insured. The missing was none. The woman who was 52 years old was buried under garden lantern and died. And a few people were injured in neighboring prefectures, Toyama, Niigata. Table 3 shows the number of houses destroyed in Ishikawa prefecture. 638 houses were completely destroyed, 1,563 houses were half destroyed, 13,553 houses were partly destroyed and 4,196 non-residential houses were damaged. 280 Table 2 Human sufferings in Ishikawa Human suffering (person) Ishikawa Serious and prefecture Dead Serious Slight slight Nanao city 127 17 110 Wajima city 1 110 41 69 Shiga town 45 4 41 Anamizu town 39 2 37 Noto town 12 2 10 Other 835 Total 1 341 69 272 Table 3 Houses destroyed in Ishikawa prefecture Ishikawa Houses destroyed Non-residence prefecture Completely Half Part Nanao city 50 230 2141 311 Wajima city 496 1,008 7,622 2,770 Shiga town 10 200 2,181 768 Anamizu town 72 91 981 221 Noto town 1 10 190 18 Other 9 24 438 92 Total 638 1,563 13,115 4,104 The road along the coastline and mountain were blocked by landslides or falling rocks. Right after the earthquake, impassable places came to 24 points in 18 lines. But as of April 27 th, impassable ones were 4 points in 4 lines. And Noto toll road was blocked right after the earthquakes. But it was completely resumed until April 27 th. As concerns the life line system, there were a lot of damages in their facilities. In waterworks, the water supply was cut off right after the earthquake in 3 cities and 5 towns, the total suspension were 13,290 houses.In Wajima city and Anamizu town, because of the lack of alternative supply water, the supply water to general hospital was cut off and some patients received the dialysis were forced to move to another hospital. But the suspension finished about 10 days after. As concerns the sewerage, the manholes stuck out from the roads and some pipes 281 snaked away. But the big accident did not occur because they used temporary pumps to secure the sewage flow. As concerns the gas supply service, since people used gas cylinders, the damages were nothing. In the gas supplying areas including Kanazawa city, the micro-computer meter (the device to intercept the gas at a gas meter) worked well at the time earthquake occurred. Many calls inquiring the restoration rushed to the company, so they were very confused. The standstills were completely restored until that evening. The damages of telephone lines were nothing. But since many people made a call at the same time right after the earthquake, the telephone lines were suspended for a while. 2. THE MAIN DAMAGES OF WATER PIPE AND FACILITIES There are a lot of characteristic differences in the facilities of water supply system comparing to other infrastructure. For example, the quality of water changes while being treated and transported. And with the formation, the almost of all facilities are chained with each other and they also make multiple systems. Therefore, in case we will make the seismic measures, it is very important to know the special qualities of facilities in advance. In case of Noto’s, to investigate the damages of facilities and to make the anti-seismic measures in the future, we must correctly analyze the basic data on damages of each facility. And then we must to investigate the reference to damages. 2.1 Anti-seismic measures against the pipe damages This time, concerning to the characteristic damages of water pipes, most of them had occurred near rivers, edges of seaside, bank and so on. On the other hand, with the difference of the pipe material, there were a lot of damages of vinyl pipes in the first place, and the second was asbestos pipes, the third was on steel pipes (with screw joints). And in ductile pipes, it was reported that some types of joints got detached in the bad soil conditions. The other hand, damage was nothing in the ductile pipe using the anti-seismic joints. According to these results, it is important to take the ground condition into account in order to select the type of joint and material of pipe. 282 Fig.5 shows topographical divisions and points where main pipes were injured. There were some damages at the bridges of water supply including ones hanged on the bridges which are not exactly constructed based on the technical guidance published by Japan Water Works Association or WSP (Water Steel Pipe Association). We must estimate the anti-seismic measures including the consequence of daily maintenance work. In the damages of aqueduct, the pipe of 250mm diameter made of reinforced concrete were injured at several places in the mountainous area of Anamizu town. There was a suspension of water supply because of the damages. By the damages of main pipe line and an aqueduct, they could not also supply enough water to the general hospital in Wajima city and Anamizu town. It showed a significance of the anti-seismic measures on water main pipe line. It should be notable that they had not used the national subsidy to strengthen pipelines until now. Table 4 Numbers of damages on pipe material and statesof damages in Nanao city where pipes were mostly injured Material of un- DIP CIP ASP SP PE VP Other total pipe known Slip-out joint 1 5 1 15 1 23 Leak of joint 6 2 5 11 2 26 Breakage of 10 6 16 Figure of pipe damages Attachment 5 1 6 Other 2 2 Total 12 2 20 12 0 26 0 1 73 Pipe length (km) 280.8 11.5 89.8 6.8 3.9 172.4 0.3 565.4 Ratio of damages 0.04 0.17 0.22 1.78 0 0.15 0 0.13 (number/km) DIP: Ductile iron pipe CIP: Cast iron pipe ACP: Asbestos cast pipe SP：Steel pipe PE: Polyethylene pipe VP: Vinyl pipe Other: Stainless steel 283 Fig. 5 Topographical divisions and points where main pipes and joints were damaged in Nanao city ▲ ■ ■ ■ ◆ ◆ ▲ ■ ■ ■ ◆ ■■ ◆ ■ ▲■ ◆▲ ● ■■ ▲▲ ■■ ■ ◆ ● ● ▲ ■ ◆ ◆ ● ◆▲★★ ◆ ● ◆● ● ● ● ● ● ◆ ▲ ● ● ■ ● ● ■ ● ◆ ◆ ★ ▲ 2.2 Anti-seismic measures against the damages of facilities It was a feature in this earthquake that two stainless panel tanks had been used as service reservoirs were injured. This type of water tank has some advantages, for example, anti-seismic, watertight, cost performance, maintenance free and so on. For those reason, they have many tanks like this in water supply services in Japan. (A company built 600 basins and B company built 2,000 basins). In the past case, we had some great earthquakes such as Hyogo prefecture earthquake (1995), Niigata prefecture 284 earthquake (2004). But there had been no damage to the tanks like above at the time. In this time, one of 30 tanks that a company had constructed was injured. I consider those are as follows. (1) Loading over the design value of earthquake movement (2) Lack of cross section size and strength of the material (3) Bad construction There were many clacks and sinking around the facilities where damages occurred and we could see uneven sinking of the foundation, we think the facilities were damaged by many multiple factors due to the earthquake. 3. THE SUGGESTION REGARDING TO BASIC IDEAS OF THE ANTI- SEISMIC MEASURES IN THE FUTURE 3.1 Basic ideas of the anti-seismic measures for small waterworks The almost water works in the Noto peninsula area are small-scale. In case of emergency, they could not exchange water with each other and the facilities would easily go off line. As the result, the suspension of the water supply would extend widely and rapidly, so we have to make the emergency water supply plan by combining the concentrated water supply system and the dispersed one according to the scale of water source, the topography and so on. The definition of these two types of water supply system is as follows. The concentrated water supply system means it supplies water to every town or village through long raw water main and distribution pipes from remote water sources. The dispersed one means it supplies water to towns or villages from their own water sources. As one example of dispersed supply systems, we could show the small membrane filter equipments that were easy to convey and were leased by a membrane maker. 3.1.1 Anti-seismic measures in case of one water supply system If there is just only one supply system, we would absolutely encounter the overall suspension of the water supply and it will take a long time to be restored. Therefore, the basic facilities have to be more earthquake-proof than any other facilities based on the seismic-capacity evaluation. And it is necessary to take measures as below on the assumption of the damages. 285 (1) A dual system of aqueduct and water main for risk dispersion. (2) A wide area backup system like building connecting pipes that can send or get water to from neighboring towns and cities. (3) A survey on spare and alternative water source and listing of those. (4) Having a simple purification plant to avoid the risk of suspension. And in case we renew the facilities based on the measures like above, we have to build a water system combining the concentrated and dispersed type. 3.2 The issues and problems of anti-seismic measures for small waterworks in Japan 3.2.1 Administer the water works in a wide area Small and medium-scale waterworks in Japan are converting their business to that in wide area thorough integrating other smaller-scale waterworks under the assistance of the Ministry of Health, Labor and Welfare. They think they could get the benefit from the business by that. But in this case, since the history of the business in a wide area was not so long. They could not keep the enough staffs to maintain the facilities that were widely scattered in that area. 3.2.2 Entrusting the business to private sector In Japan, we have a basic principle that that municipalities like cities and towns should run the water supply business by themselves according to the Waterworks Law. Therefore, based on the self-supporting account system, public enterprises have done the main business and private companies have just played supplementary works until now. By the amendment of the Waterworks Law which was approved in July 15th 2003, the private sector could have been able to participate in the administrative work in the facilities of water supply services. But the private sector generally does not have enough experiences on the aspect of water supply service. In Noto’s case also, it was pointed out that they could not work in adequate cooperation with the employers to cope with the emergency at that time. In the future, we have to make sure that the mutual responsibility, a chain of command and so on in emergency are clearly described on a contract. In addition we should carry out the joint exercises to raise the awareness of 286 crisis-management for emergency situations. The main aim in this exercise is to materialize the role of both sides with effective measures in an emergency. References [1] http://www.seisvol.kishou.go.jp/eq/shindo_db/shindo_index.html (The meteorological agency) [2] http://www.eri.u.tokyo.ac.jp/jhome.html (Tokyo university seismic institution) [3] http:/www.jishin.go.jp/main/chousa/07apr_noto/p03.htm (The committee for seismic research) [4] http://www.seisvol.kishou.go.jp/eq/gaikyo/monthly200703/200703index.html (The meteorological agency) 287 288 Seismic Performance Evaluation of LADWP Water System Using GIRAFFE Craig A. Davis, Jianping Hu, Thomas D. O’Rourke and Amanda L. Bonneau ABSTRACT This paper describes a decision support system currently under development at Cornell University to plan operations, emergency response, and new system facilities and configurations for optimizing water supply performance during and after earthquakes and how it is being implemented for use by the Los Angeles Department of Water and Power (LADWP). The system is generic, and the architecture of its computer programs is adaptable to any water supply network. The system works in conjunction with an easily accessible hydraulic network model, EPANET, and a special program for damaged network flow modeling, known as Graphical Iterative Response Analysis for Flow Following Earthquakes (GIRAFFE). The decision support system was developed using the LADWP water supply and distribution system as a test bed. Simulation results are presented for a 1994 Northridge earthquake repeat scenario. The seismic performance, measured as the ratio of post- to pre-earthquake water supplied at demand nodes, is provided for the entire water network and different water service zones both immediately after and 24 hours after the earthquake. Losses associated with disruption of the Los Angeles Aqueducts, loss of electric power, and/or earthquake-induced pipeline damage are modeled and compare well with actual earthquake performance. The decision support system and GIRAFFE are in their final stages of development, and the results presented herein are representative of modeling capabilities and system performance but are not definitive results of the final modeling process. The 1994 Northridge earthquake repeat scenario represents the initial implementation steps for calibrating results against the actual Northridge earthquake and obtaining practical results useful for making seismic related decisions on how to proceed with significant on-going system-wide modifications necessary for water quality improvements. The LADWP plans to continue support for developing GIRAFFE and implementing the decision support system to aid in long-term seismic vulnerability assessments and planning capital improvement project developments. Craig A. Davis, Waterworks Engineer, Geotechnical Engineering Group, Los Angeles Department of Water and Power, 111 N. Hope Street, Room 1368, Los Angles, CA, 90051. Jianping Hu, Civil Engineering Associate, Geotechnical Engineering Group, Los Angeles Department of Water and Power, 111 N. Hope Street, Room 1368, Los Angles, CA, 90051. Thomas D. O’Rourke, Briggs Professor, Cornell University, 273 Hollister Hall, Ithaca, NY 14853 Amanda L. Bonneau, NSF Graduate Research Fellow, Cornell University, 267 Hollister Hall, Ithaca, NY 14853 289 LADWP WATER SYSTEM OVERVIEW The Los Angeles Department of Water and Power (LADWP) is the largest municipally owned utility in the United States. The LADWP provides water and electric service to more than 4 million Los Angeles City residents and businesses in a 120,435 ha (465 mile2) area. The Water System provides the City of Los Angeles about 813,775,000 m3 (215 billion gallons) of water annually through 11,633 km (7,230 miles) of transmission and distribution lines. The LADWP has developed many water supply sources to allow redundancy for normal and emergency operations [1]. Figure 1 shows the supply sources from the First and Second Los Angeles Aqueducts (hereinafter referred to as the Los Angeles Aqueducts), Metropolitan Water District of Southern California (MWD) connections, and the Los Angeles River groundwater and other basins. The numerous tanks and reservoirs contained in the water system store water from these various sources for distribution throughout the City. The numerous MWD connections throughout the City provide water from the Colorado River Aqueduct and California Aqueduct for distribution. In the event of an earthquake, the water system draws upon the many available sources to provide a reliable water supply. Following an earthquake, these supply redundancies allow water to be provided to unaffected areas of the City with little or no interruption, and also significantly aid in post-earthquake recovery to severely damaged portions of the water system. Within the severely damaged portions of the system, the redundant supplies and in-City storage significantly reduce the outage time an average resident experiences following an earthquake. Terminal storage for the Los Angeles Aqueducts was developed at the City’s northern limits, in an area now called the Van Norman Complex (VNC), as shown in Figure 1. The VNC is an important site for collecting water supply and distributing it to the city because it serves as the Los Angeles Aqueducts terminus and also receives the majority of MWD water. As the main water supply hub for the entire City, about 75 percent of the City’s annual water supply passes through the VNC before it is distributed throughout the City. In order to provide a reliable water supply throughout the system, numerous large diameter [up to 3048 mm (120-inches) in diameter] supply trunk lines originate from the VNC and other supply sources and extend to various reservoirs and tanks throughout the City. Other trunk lines interconnect the main supply lines to allow for distribution of different water sources to many parts of the City. The trunk lines are also equipped with many valves that allow isolation of the water supply. The trunk line interconnectivity and isolation capability provides great versatility in the ability to supply water to many parts of the system from a variety of sources. In many cases, damaged trunk lines can be isolated for repair without a significant water outage. At the same time, water can still be supplied to damaged portions of the distribution system from other sources in order to provide the needed water surcharge for finding and repairing pipe breaks. The supply line redundancy is a significant component in creating a system resilient to severe earthquake effects, which was proven to be effective in the 1971 San Fernando and 1994 Northridge earthquakes [1][2][3]. 290 Los Angeles Aqueducts Van Norman Complex Figure 1. LADWP water supply and transmission system showing the first and second Los Angeles Aqueducts entering the City from the north, major trunk lines (solid bold lines), MWD supply lines (dashed lines), reservoirs (labeled), major tanks (solid circles), other LADWP water facilities as labeled, freeways (labeled solid lines), within the City boundaries. 291 WATER SYSTEM MODIFICATION AND CHALLENGE The LADWP is presently undertaking an extensive capital improvement program to meet the requirements of the United States Environmental Protection Agency and California State Department of Health Services requirements stipulated in the Surface Water Treatment Rule and Disinfection Byproducts Rule. Significant water system changes are necessary to meet their requirements. System changes include the removal of Encino, Hollywood, and Stone Canyon Reservoirs from normal operating service (see Figure 1), which places a much greater importance on the VNC and Los Angeles Reservoir for water supply throughout the City on a daily basis. These three reservoirs will retain storage for emergency supply purposes. Silver Lake Reservoir is planned to be permanently removed from service in the near future and replaced with alternate covered storage of reduced capacity. The Los Angeles Reservoir is planned to be divided in half with a new embankment dam to allow for greater system flexibility and each side will be covered with a floating cover. In addition, many miles of new large diameter trunk lines are being installed to allow greater system flexibility for the water quality projects and also as a part of a trunk line replacement program. The replacement program was initiated following a study of older trunk lines which identified several that were in need of repair and replacement. Although in-City storage capacity is being significantly reduced, the increased number of trunk lines being constructed will provide greater redundancy and flexibility. It is becoming more important to understand the Los Angeles Water System’s ability to withstand seismic hazards as the water quality and other needed improvements are being implemented. The system changes necessary for water quality purposes leave ambiguity and questions concerning how the system may perform in future earthquake scenarios similar to or greater than what the City experienced in 1971 and 1994. Will the modified Los Angeles Water System perform equally as well today as it did in 1994 if subjected to a repeat earthquake? What is the adequate water storage for the post-earthquake recovery if a similar or larger earthquake is experienced in the future? In order to answer these and other questions it is necessary to use advanced computer modeling techniques incorporating a wide range of parameters effecting water system seismic performance and recovery capability. Using the advanced modeling, the entire Los Angeles Water System can be evaluated and assessed for vulnerabilities to a large number of reasonable earthquake scenarios. Unfortunately, assessing the entire Los Angeles Water System within the complex and complicated seismic environment in which it is located is a difficult and time consuming process. As a result, comprehensive seismic assessments cannot be practically performed to meet the high priority and demanding water quality improvement schedules. At the same time, seismic risk concerns cannot be disregarded while undertaking the system modifications. For the Los Angeles Water System, a 1994 Northridge earthquake repeat scenario serves as a tangible benchmark for assessing how the water quality improvements affect the system’s current earthquake performance and recovery capability and can be used for making initial decisions on additional modifications needed to improve system seismic performance. A Northridge earthquake repeat scenario can also help guide on-going capital improvement project developments to ensure seismic hazards affecting the over-all water system performance is properly 292 considered in relation to water quality and other hazard concerns (e.g., dam safety). The actual Northridge earthquake and associated system performance also serves to calibrate the computer models and ensure they are being properly implemented. The remainder of this paper describes an advanced decision support system models currently under development and how they are being implemented to assess the Los Angeles Water System and provide preliminary system performance results for a Northridge earthquake repeat scenario. Following final model development and implementation, the LADWP plans to perform more comprehensive system-wide seismic evaluations and implement prudent seismic improvements beyond that associated with a repeat of the Northridge earthquake. DECISION SUPPORT SYSTEM MODEL Research supported by the Multidisciplinary Center for Earthquake Engineering Research (MCEER) at Cornell University and the LADWP has focused on the development of a decision support system to plan operations, emergency response, and new system facilities and configurations to optimize water supply performance during and after earthquakes. The system is generic, and the architecture of its computer programs is adaptable to any water supply. The system works in conjunction with an easily accessible hydraulic network model, EPANET, and a special program for damaged network flow modeling, known as Graphical Iterative Response Analysis for Flow Following Earthquakes (GIRAFFE). For details on the development and evaluation of GIRAFFE, refer to dissertations by Wang [4] and Shi [5]. The decision support system was developed using the LADWP water supply as a test bed. As applied to the LADWP network, the computer model simulates all 11,633 km (7,230 miles) of water trunk and distribution pipelines and related facilities (e.g., tanks, reservoirs, pressure regulation stations, etc.) in the LADWP system. The decision support system accounts for the aggregated seismic hazard in Los Angeles through an ensemble of 59 scenario earthquakes. The 59 scenario earthquakes also provide a library of seismic scenarios, from which engineers can select specific scenarios or combinations of scenarios to assess system performance. The decision support system works with risk and reliability assessment tools to provide metrics of system performance. The computer simulations account for the interaction of the water and electric power supplies, and model output can be used to evaluate the regional economic and community impacts of water losses. All system input and output can be visualized through GIS with advanced query logic and web-based features. The simulations are dynamic in time, and can account for loss of service as tanks and local reservoirs lose water over time through leaks and breaks in pipelines. WATER SYSTEM SEISMIC PERFORMANCE SIMULATIONS The Northridge earthquake repeat scenario was selected for the implementation phase to provide benchmarking of actual system performance during the 1994 Northridge earthquake. LADWP Water System performances due to loss of water supply, loss of electric power, and/or earthquake induced pipeline damage are modeled with GIRAFFE 293 for the Northridge earthquake repeat scenario. It should be noted that the decision support system and GIRAFFE are in their final stages of development, and the results presented herein are representative of modeling capabilities and system performance but are not definitive results of the final modeling process. System Modeling The Northridge earthquake repeat scenario consists of a Mw 7.0 that is one of the 59 scenario earthquakes [6] used to assess the aggregated seismic hazard for the LADWP system. This event is similar to the actual Mw 6.7 1994 Northridge earthquake and hence familiar and meaningful for operators and customers. The Mw 7.0 scenario earthquake is slightly stronger than its 1994 counterpart, but sufficiently similar to provide results that can be assessed relative to experience with actual system performance during the Northridge earthquake. System simulations have been performed to show the aggregated effects during an earthquake of loss in functionality of the Los Angeles Aqueducts, loss of electric power due to earthquake effects, damage from local permanent ground deformation to trunk and distribution pipelines, system-wide damage from transient ground deformation effects, and damage to facilities. The damage can also be de-aggregated to show the most important sources and quantify their ramifications on the system. System performance is expressed in terms of system Serviceability Index (SI), which is the ratio of flow at demand nodes before and after the earthquake. There are 1,052 demand nodes that are geographically distributed throughout the system. The SI can be determined for the entire system or for any part of the system so that the spatial variability of SI can be evaluated. The system response was evaluated for 15 water service areas, shown in Figure 2. Water service areas are geographic groupings of pipelines, pumps, valves, tanks, reservoirs, and demands that can be analyzed individually. From north to south the water service areas are: Granada Hills (GH), Foothills (FH), Sunland-Tujunga (ST), Valley Floor A, B and C (VF A, VF B, VF C), Encino Hills (EH), Santa Monica (SM), Hollywood Hills (HH), Mount Washington (MW), Highland Park (HP), Santa Ynez (SY), Westside (WS), Central City (CC), and Harbor (H). The Valley Floor, Central City, and Westside water service areas serve the highest demands in the system, delivering water to the densely populated San Fernando Valley, downtown Los Angeles, and western Los Angeles communities, respectively. The remaining water service areas sit at higher elevations in the mountains surrounding Los Angeles, except for the lower elevation Harbor water service area. By showing the results for the 15 water service areas, one is able to understand the spatial variability of the system performance as expressed in terms of SI. 294 GH FH ST VFB VFC VFA EH HP SM HH MW SY WS CC H Figure 2. Water Service Areas in the LADWP system. System Performance due to Los Angeles Aqueduct Outage The Los Angeles Aqueducts transport water from the Eastern Sierra Nevada in Northern California to the City of Los Angeles and account for nearly 50% of the annual LADWP water supply. During the 1994 Northridge earthquake, seismically induced damage to the Los Angeles Aqueducts disrupted aqueduct water at the same time that damage in the Foothill Feeder curtailed availability of water from MWD. In planning for a Northridge earthquake repeat scenario, it is appropriate to assume disruption in the Los Angeles Aqueducts without inter-tie backup from MWD. Figure 3 presents the SI for the 15 water service areas at 24 hours with the Los Angeles Aqueducts not contributing to the LADWP water supply and with no other supply supplementing the Los Angeles Aqueducts. The system SI is 85% 24-hours after the earthquake without the Los Angeles Aqueduct supplies. Comparatively, an analysis performed with the Los Angeles Aqueducts in operation produces a 24 hour system SI of 100%. As shown in Figure 3, the water service areas most affected by the loss of the Los Angeles Aqueducts are the GH, FH and VF C areas in the upper San Fernando Valley. FH and VF C have a SI of 53% and 41%, respectively, while GH suffers a substantial decrease in SI to only 2%. 295 Water Service Area Serviceability at 24 hrs LA Aqueducts Off, No Damage (Entire System Serviceability: 85.0%) 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 Serviceability Index (SI) 0.1 0 H CC W SY SM VFA HH MW HP EH GH ST FH VFB VFC Water Service Area (WSA) Figure 3. 24-hour Serviceability Index for 15 Water Service Areas with Los Angeles Aqueducts off, no other damage, and no other supply supplementing the Los Angeles Aqueducts. System Performance due to Electric Power Outage Figure 4 shows the de-aggregated results for the loss of electric power, which mainly affects the operation of pump stations. In the event of power loss, pump stations with secondary sources of power, such as back up generators, will continue to operate with a modified number of pumps. Electric power outage data from the actual 1994 Northridge earthquake were used to simulate the configuration of pumps for various time increments following the earthquake event. It was found that using the configuration of pumps operating 2 hours following the earthquake for the entire 24 hour simulation produced nearly identical results (differed by less than 1%) to an analysis where power was incrementally restored to pump stations at 2, 6, 12, 18 and 24 hours. Thus, the 2 hour configuration of operational pumps was used as an equivalent power state for the 24 hour simulation. As shown in Figure 4, the system SI at 24 hours is 90.5%. The GH, ST and FH water service areas have the lowest SI of 20%, 62% and 54%, respectively. Similar results are seen for both of the single parameter studies presented in Figures 3 and 4, with water supply to the upper San Fernando Valley, primarily the GH and FH water service areas, becoming compromised. In the electric power outage case, the Van Norman Pump Station 2 loses power and does not have a back-up power source. Although water is available, this station is not functioning and cannot pump water to the upper San Fernando Valley. When the Los Angeles Aqueducts are disrupted, water flow is curtailed to the upper San Fernando Valley. This lack of water produces similar results as those for the electric power outage scenario where water is available, but the means to distribute it is compromised. 296 Water Service Area Serviceability at 24 hrs LA Aqueducts On, Electric Power Outage at 2hrs (Entire System Serviceability: 90.5%) 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 Serviceability Index (SI) 0.1 0 HCCWSYSMVFAHHMWHPEHGHSTFHVFBVFC Water Service Area (WSA) Figure 4. 24-hour Serviceability Index for 15 water service areas with electric power outage, Los Angeles Aqueducts on, and no other damage. System Performance with/without Emergency Storage Reservoirs Since the 1994 Northridge earthquake, 3 large reservoirs have been taken out of normal operational service. The loss of the Encino, Hollywood and Stone Canyon Reservoirs has reduced the LADWP water storage by 30 x 106 m3 (8 x 109 gallons) within the City. However, these reservoirs remain for emergency operational use. Simulations were performed for the 2007 LADWP water system configuration with and without these 3 reservoirs supplying water to the system, when subject to transient ground deformation effects from the Mw 7.0 Northridge earthquake repeat scenario, permanent ground deformation to trunk and distribution pipelines, electric power loss, and the Los Angeles Aqueducts out of service. The purpose of these simulations is to obtain a better understanding of the emergency storage reservoirs’ importance to post- earthquake operations. Figure 5 shows the serviceability results at 0 hours (immediately following the earthquake) for the 3 reservoirs closed. The 0 hours system SI is 79.4% and 14 of the 15 water service areas have a SI of above 75%. Figure 6 shows the serviceability results at 24 hours after the earthquake for the 3 reservoirs closed. The 24 hours system SI is 39.1% and 8 of the 15 water service areas have a SI below 25%. The SI results for 0 hours after the earthquake for the 3 reservoirs open is not shown, as they are very similar to those shown in Figure 5. Figure 7 shows the serviceability results at 24 hours after the earthquake for the 3 reservoirs open. The 24 hours system SI is 51.3% and 5 of the 15 water service areas have a SI below 25%. Figure 8 highlights that in both cases, water service is largely compromised in the upper San Fernando Valley and Santa Monica regions, but when the 3 reservoirs are open they improve the WS, HH and WS water service area SI to levels above 25%. 297 Water Service Area Serviceability at 0 hrs Repeat NR EQ Scenario, Distribution and Trunk Line Damage, Electric Power Outage 1.0 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 Serviceability Index (SI) (Entire System Serviceability: 79.4%) 0.1 0.0 H CC W SY SM VFA HH MW HP EH GH ST FH VFB VFC Water Service Area (WSA) Figure 5. 0-hour Serviceability Index for 15 water service areas when Encino, Hollywood and Stone Canyon Reservoirs are closed with system pipeline damage, electric power outage, and Los Angeles Aqueducts off. Water Service Area Serviceability at 24 hrs Repeat NR EQ Scenario, Distribution and Trunk Line Damage, Electric Power Outage 1.0 0.9 (Entire System Serviceability: 39.1%) 0.8 0.7 0.6 0.5 0.4 0.3 0.2 Serviceability Index (SI) Serviceability 0.1 0.0 H CC W SY SM VFA HH MW HP EH GH ST FH VFB VFC Water Service Area (WSA) Figure 6. 24-hour Serviceability Index for 15 water service areas when Encino, Hollywood and Stone Canyon Reservoirs are closed with system pipeline damage and electric power outage, and Los Angeles Aqueducts off. 298 Water Service Area Serviceability at 24 hrs Repeat NR EQ Scenario, Distribution and Trunk Line Damage, Electric Power Outage, 3 Reservoirs Open 1.0 0.9 (Entire System Serviceability: 51.3%) 0.8 0.7 0.6 0.5 0.4 0.3 0.2 Serviceability Index (SI) 0.1 0.0 H CC W SY SM VFA HH MW HP EH GH ST FH VFB VFC Water Service Area (WSA) Figure 7. 24-hour Serviceability Index for 15 water service areas when Encino, Hollywood and Stone Canyon Reservoirs are open with system pipeline damage and electric power outage, and Los Angeles Aqueducts off. Hollywood Reservoir Encino Reservoir Stone Canyon Reservoir (a) Encino, Hollywood and Stone Canyon (b) Encino, Hollywood and Stone Reservoirs Closed Canyon Reservoirs Open (Entire System Serviceability: 39.1%) (Entire System Serviceability: 51.3%) Figure 8. Comparison of 24 hour Serviceability Index for 15 water service areas when Encino, Hollywood and Stone Canyon Reservoirs are open and closed with system pipeline damage and electric power outage, and Los Angeles Aqueducts off. 299 To check the validity of the analyses, the 2002 LADWP system configuration response to Mw 6.5 and Mw 7.0 Northridge earthquake repeat scenarios was simulated for the effects of system-wide ground wave effects, electric power loss, permanent ground deformation, and the loss of the Los Angeles Aqueducts. The 2002 LADWP system configuration had network characteristics more closely resembling that during the Mw 6.7 1994 Northridge earthquake, with Encino and Stone Canyon Reservoirs open. Winter water demand conditions were modeled because the 1994 earthquake occurred in January. The winter demand is approximately 43% of the summer water demand. The system SI after 24 hours for the Mw 6.5 and Mw 7.0 Northridge scenario earthquakes varies from 78% to 65%, which compares favorably with a system SI of approximately 70% after the actual Northridge earthquake. CONCLUSION The Los Angeles Water System is currently undergoing significant system wide changes to improve the quality of the water supplied to customers. In order to understand the post-earthquake performance of the modified water system, the LADWP has undertaken a cooperative program with MCEER to perform a systems analysis, which will help identify vulnerabilities in the supply and distribution systems. Studies on the Los Angeles Water System with the decision support system to date have focused on a Northridge earthquake repeat scenario. The studies show the great importance of dynamic behavior over time, especially during the first 24 hours after the earthquake when leaking water through damaged pipelines diminishes local tank and reservoir levels, thereby reducing system Serviceability Index (SI). The studies show the importance of disruption in flow from the Los Angeles Aqueducts and electric power losses. Each of these effects has similar consequences for the Los Angeles Water System, resulting in low SI for water service areas in the northern part of the Los Angeles. The studies also show the effects of lost storage capacity. Over the past 10 years three large reservoirs (Encino, Hollywood, and Stone Canyon) have been taken out of normal operational service because of water quality concerns, resulting in a reduction of approximately 30 x 106 m3 (8 x 109 gallons) of readily available water and placing greater dependence on the Los Angeles Reservoir. For peak summer demands, the SI for the entire network 24 hours after the earthquake is increased by approximately 30% if these three reservoirs are returned to service on an emergency basis. The decision support simulations explicitly demonstrate the most important local and system-wide effects on the Los Angeles Water System seismic response and recovery and provide an initial quantification on how the use of Encino, Hollywood, and Stone Canyon Reservoirs in emergency conditions improves the overall system serviceability. The decision support system and GIRAFFE are in their final stages of development, and the results presented herein are representative of modeling capabilities and system performance but are not definitive results of the final modeling process. 300 ACKNOWLEDGMENTS Support from the National Science Foundation, Multidisciplinary Center for Earthquake Engineering Research, and Los Angeles Department of Water and Power are gratefully acknowledged. REFERENCES [1] Lund, L., and C. Davis, 2004, “Multihazard Mitigation Los Angeles Water System A Historical Perspective,” ASCE Technical Council on Lifeline Earthquake Engineering, Multihazard Monograph, Craig Taylor editor, in preparation. Presentation at ASCE TCLEE Workshop, 6th US Conference on Lifeline Earthquake Engineering, Long Beach, CA, August 10, 2003. [2] Davis, C. A., 1999, “Performance of a Large Diameter Trunk Line During Two Near-Field Earthquakes, Proc. 5th U.S. Conf. on Lifeline Earthquake Engr, ASCE, Seattle, Aug., pp. 741-750. [3] Davis, C. A. and J. P. Bardet, 1995, “Seismic Performance of Van Norman Water Lifelines,” Proc. 4th U.S. Conf. on Lifeline Earthquake Engineering, ASCE, San Francisco, Aug., pp. 652-659. [4] Wang, Y., 2006, “Seismic Performance Evaluation of Water Supply Systems”, PhD Dissertation, Cornell University, Ithaca, New York. [5] Shi, P., 2006, “Seismic Response Modeling of Water Supply Systems”, PhD Dissertation, Cornell University, Ithaca, New York. [6] Lee, J., Graf, W., Somerville, P., O’Rourke, T. D., and Shinozuka, M., 2005, “Development of Earthquake Scenarios for Use in Earthquake Risk Analysis for Lifeline System,” Report for the Los Angeles Department of Water and Power, Los Angeles, CA, 34p. 301 302 Seismic Repair Rate Analysis and Risk Assessment of Water Pipelines Gee-Yu Liu, Chin-Hsun Yeh, Hsiang-Yuan Hung, and Ban-Jwu Shih ABSTRACT Seismic risk assessment of water pipeline systems is a very important task in proposing effective disaster preparedness and mitigation plans. In the literature, the individual relationship between the number of earthquake-induced pipeline repairs and ground motion parameters such as the peak acceleration, peak velocity, or strain has been studied before. With reference to the data compiled after 1999 Chi-Chi, Taiwan earthquake, regression analyses were conducted in this investigation for obtaining empirical water pipeline repair rate formulae considering the effects of ground shaking and permanent ground deformation simultaneously. The widespread observational data of strong motion and ground deformation make the attained formulae very unique when compared with the ones from other earthquakes. Accordingly, seismic scenario simulation and risk assessment of water pipeline system in the Taipei metropolitan area were performed. Tentative scenarios based on the maximum probable earthquakes have been determined for disaster reduction plans. Gee-Yu Liu, Associate Research Fellow, National Center for Research on Earthquake Engineering (NCREE), 200, Sec. 3, Xin-hai Rd., Taipei 106, Taiwan. Chin-Hsun Yeh, Research Fellow, NCREE, 200, Sec. 3, Xin-hai Rd., Taipei 106, Taiwan. Hsiang-Yuan Hung, Assistant Researcher, NCREE, 200, Sec. 3, Xin-hai Rd., Taipei 106, Taiwan. Ban-Jwu Shih, Associate Professor, National Taipei University of Technology, 1, Sec. 3, Chung-hsiao E. Rd., Taipei 106, Taiwan. 1 303 INTRODUCTION The seismic performance of water systems is by all means a pivotal factor to the resilience of a community for confronting earthquake disasters. The pipeline network of a water system is usually very large and geographically distributed that lend themselves very vulnerable to various seismic hazards including strong motion, ground deformation and soil liquefaction. In order to enhance the community preparedness and mitigate the water pipelines more effectively, it is necessary to have adequate damage assessment models and risk management strategies. This article serves as an introduction to the recent advance in the seismic repair rate analysis and risk assessment of water pipelines at the National Center for Research on Earthquake Engineering (NCREE), Taiwan. Regarding the repair rate of buried water pipelines, the pipeline inventory and damage data collected after the 1999 Chi-Chi, Taiwan earthquake offer a good opportunity for developing new empirical formulas through regression analysis. It is highly desired if the combined effect of ground shaking and deformation to the number of pipeline repairs could be expressed in a single formula. Secondly, with the Taipei metropolitan area as a testbed, the seismic risk assessment of its pipeline system has been performed, and the results have been employed for deciding the protection standards in local disaster reduction plans. WATER PIPELINE REPAIR RATE ANALYSIS Background Information The catastrophic Chi-Chi earthquake with a main shock of Richter magnitude 7.3 took place in central Taiwan on September 21, 1999. The earthquake was caused by the rupture of Chelungpu fault with rupture length greater than 90km and permanent displacement larger than 10m. As a result, more than 2,400 people died, 11,000 wounded, and 100,000 were left homeless. The earthquake also caused severe damage and disruption to lifeline systems. Regarding the water supply systems, the damage to Shihgang Dam alone reduced 40% of water supply to Taichung area. A major water-treatment plant at Fengyuan was severely damaged and a nearby main that crossed the fault was deformed and blocked [1]. The widespread damage to facilities and pipeline systems made water unavailable to many cities for long period of time. A full restoration of the water supply in Taichung City took nine days. For some rural areas, it took an even longer time to resume. GIS Database Grid System Displacements at Time Histories of LSB Control Points Strong Motion at Water Pipelines CWB Stations and Damage Data PGD Value at Each Grid Cell by PGA Values at Interpolation CWB Stations No. of Pipeline Pipeline Length Repair Points in in Each Grid Cell Each Grid Cell Ground Strain Value at PGA Value at Each Each Grid Cell by Grid Cell by Numerical Differentiation Interpolation Repair Rate and the Corresponding Ground Motion/Displacement/Strain by Moving Average Method Regression Analysis Figure 1. The analysis framework for seismic repair rate of buried water pipelines 2 304 Figure 1 depicts the analysis framework for studying seismic repair rate of buried water pipelines in this study. At first, the study area was split into uniform 0.5 km×0.5 km grid cells to create a grid system. The grid cells were employed as the basic geographic units for spatial analysis of pipe inventory, repair points and seismic parameters. Secondly, the strong motion records, from the Central Weather Bureau (CWB), Ministry of Transportation and Communication were used to estimate the distribution of PGA. Similarly, the global position measurements at control points, before and after the Chi-Chi earthquake, by the Land Survey Bureau (LSB), Ministry of the Interior were used to estimate the distribution of permanent ground displacement (PGD). The attained PGD distribution was further used to estimate the distribution of ground strain. Then, the water pipeline inventory and the associated repair data were splitted into each grid cell. After partition of various kinds of data into grid cells, it became ready to carry out the spatial analysis of pipeline repair rate and the further regression analysis. The Study Area, Water Pipeline and Repair Data A total of 11 cities and towns whose pipeline inventory including location, diameter, material, etc., and the data of earthquake-induced pipe repairs have been collected, digitized and imported into a GIS-based database. These cities and towns include Fengyuan, Jhuolan, Dongshih, Shihgang, Wufong, Lugang, Huatan, Fusing, Puli, Mingjian and Douliou, see Figure 2. Figure 2. The study area of 11 cities and towns in central Taiwan The nominal diameters of water pipes in the database vary between 20mm and 2,400mm. Table 1 summarizes the diameter range, total length and number of repairs of large, medium and small pipes in the database. It is noted in Table 1 that the average repair rate for small pipelines was several times larger than those of medium and large pipes. The small pipes, with nominal diameter less than 65 mm, are often used to connect distribution pipes to the customer ends. Many researchers do not include small pipes in their study as the corresponding data may be incomplete in the database. For this reason, small pipes are excluded from the analyses in this study. 3 305 More than 90% of the pipes and repair points in the database belong to ductile pipes, such as PVC, PE, DI and steel pipes. Although the pipe material is one of the factors that influence the repair rate after earthquakes, we will not distinguish the pipe material for simplicity, in the following regression analysis. Table 1. The pipeline information in the study area Type Diameter Range Length No. of Repairs Large d > 150mm 745km 159 Medium 150mm ≥ d ≥ 65mm 1,989km 854 Small d < 65mm 740km 1,801 Distributions of Ground Motion Intensity and Deformation More than 400 sets of three-component free-field ground motions were recorded during the Chi-Chi earthquake. Here, the PGA value at each CWB strong motion station referred to the geometric mean of PGA values in the east-west direction and north-south direction. The PGA value at each grid cell is then calculated through numerical interpolation (and extrapolation). In order to prevent the undesired peaks and dips that might be artificially generated, the algorithm of minimum curvature is employed for the numerical interpolation. While for the PGD, the high precision GPS survey data before and after the Chi-Chi earthquake by the LSB has been well compiled by Chang et al. [2]. It serves as a good basis for finding out the actual change in topography in Taiwan caused by the earthquake. Similar to the numerical interpolation for attaining the PGA distribution, each component of the displacement field can be separately estimated from the measured value at each LSB control points. The only difference here would be that the displacement field in the hanging wall area and the corresponding one in the footwall area have to be estimated separately to preserve its discontinuity along the Chelungpu fault. Finally, we may have the PGD distribution by calculating the magnitude of displacement vector at each grid cell. From the attained distribution of PGD values in three directions, the ground strain can be derived through direct calculation. The calculated distributions of PGA, PGD and ground strain are depicted in Figure 3. Figure 3. The distributions of PGA (left), PGD (middle) and ground strain (right) in Taiwan caused by the Chi-Chi earthquake 4 306 Regression Model and Analysis Approach Based on the grid system mentioned above, the pipeline length and number of repairs in each grid cell, the estimated PGA, PGD and ground strain of each grid cell have all be calculated and prepared as GIS layers. Overlaying these layers, it is ready to obtain the empirical relationship between pipeline repair rate and various seismic parameters. Here, the pipeline repair rate is defined as the number of repairs divided by the pipeline length. Conventionally, the pipe repair rates were counted based on an equal interval value of ground motion intensity and/or deformation. The defect of this approach, as has been pointed out Hwang et al. [3], is that the pipeline length may be quite different in each interval and the computed pipe repair rate may vary significantly depending on the selected interval value. To confront this defect, they have instead proposed an alternative approach: the repair rate data points used for regression analysis are computed from the pipeline data of approximately equal length and may associate with different interval values of seismic parameters. In order to further increase repair rate data points for a better description of pipeline vulnerability, a moving average method was used in this study. Using this, data points at the same interval value can be attained. In order to simplify the analysis, Yeh et al. proposed that the pipeline repair rate is a function of two seismic factors: the ground shaking and the permanent ground deformation. It is further assumed that the two factors are not correlated and the pipeline repairs caused by them can be superposed. In other words, the pipeline repair rate can be expressed as [4]: += RRRR shake RR deform (1) where RR shake and RR deform are the repair rates caused by the ground shaking and the permanent ground deformation, respectively. The Chelungpu fault is a thrust fault and its fault plane has a small dip angle. As a result, the severity of ground deformation in the hanging wall area was much greater than the one in the footwall area. For this reason, the regression analysis was divided into two stages. In the first stage, we excluded the pipeline data from regions with ground strain greater than 0.001 and derived the regression formula for the first term in the RHS of Eq. (1), i.e. RR shake. Then, after deducting from the observed data the contribution from RR shake, the regression formula for the second term in the RHS of Eq. (1), i.e. RR deform, was derived in the second stage. Regression Results The repair rate data points and regression results for RR shake have both been depicted in the left sub-figure of Figure 4. A pipeline length of 200km was employed for each data point, which separates from each other at 10cm/sec2. The R2 values in the regression analyses were both found to be greater than 0.9, which means that PGA can be a suitable estimator for the seismic vulnerability of buried pipelines in the PGA-dominate region. Similarly, the repair rate data points and regression results for RR deform have both been depicted in the right sub-figure of Figure 4. A pipeline length of 150 and 200km was employed for each data point of large-size and mid-size pipelines, respectively. The data point separates from each other at a strain interval of 0.002. Here, the R2 values in the regression analyses, though less than those for PGA, were both found to be greater than 0.7. Taking into account the randomness of repair data caused by the deduction of contribution from ground shaking, the pipeline repair rates seem well correlated with the ground strain. 5 307 Finally, the resultant regression models of buried water pipeline repair rate under the combined effect of PGA and ground strain can be expressed as Large-size pipe: −5 1.328 849.7PGA10637.8RR ⋅+⋅×= ε 0.701 (2) Mid-size pipe: −5 1.768 634.6PGA10103.1RR ⋅+⋅×= ε 0.381 (3) It is worth noticing that the widespread observations of strong motion and ground deformation (up to 700gals and 0.007, respectively) make the attained formulae Eq. (2) and Eq. (3) very unique when compared with the data from other earthquakes. They can be utilized for water pipeline loss estimation in Taiwan without the need of undesired extrapolation. 10 10 1 1 RR (number / km) / RR (number RR km) (number / 0.1 0.1 0.01 0.01 100 300 500 700 0 200 400 600 800 0 0.002 0.004 0.006 0.008 Pga (gal) Strain Figure 4. The relationships between RR shake and PGA (left) and RR deform and ground strain (left); red: mid-size pipelines, blue: large-size pipelines SEISMIC ASSESSMENT OF THE PIPELINE SYSTEM IN TAIPEI AND APPLICATION Methodology for Seismic Risk Assessment Based on the source parameters of an earthquake scenario, the distribution of ground motion intensity and the ground failure extent can be estimated through empirical attenuation laws, site modification factors, and soil liquefaction assessment models. Furthermore, depending on the site-dependent ground shaking intensity and ground failure extent, the damage-state probabilities of various lifeline components, such as buried pipeline segments, electric power substation, and highway bridges, can be obtained also. Two types of seismic sources are included in establishing Taiwan’s seismic scenario database (SSD) developed at NCREE by Yeh [5]. The first type belongs to active faults that have known geographic properties such as surface fault trace and dip angle of fault plane. The fault geometry, characteristic of earthquake magnitude, average annual slip rate, etc. of each active fault in Taiwan have been investigated by the Central Geological Survey Bureau (CGS), Taiwan. In this study, only Type I active faults classified by CGS were taken into consideration, as shown in Figure 5. The second type of seismic sources is often referred to as an area source that has unknown fault trace and rupture direction. In order to cover all the possible earthquake events, a rectangular region circumscribing Taiwan was divided uniformly into 500 grids, as illustrated in Figure 5, too. Six focal 6 308 depths, which are 10, 20, 30, 50, 70 and 90 km, were chosen to represent possible future earthquakes. In each grid and at each focal depth, earthquake magnitudes from 5.1 to 7.5 with 0.2 increments were selected for the SSD. Finally, combining the seismic scenario database and the results of probabilistic seismic hazard analysis, one can obtain the seismic event loss table which can be used to calculate various kinds of risk statistics in different regions or in specific targets. 26 Keelung Xincheng Fault Taoyuan 25 Taipei Shitan Fault Shenzhuoshan Fault Hsinchu Ilan Tunzijiao Fault Miaoli Chelongpu Fault Taichung Hualien 24 Changhua Meilun Fault Nantou Dajianshan Fault Yunlin Yuli Fault Meishan Fault Chiayi Qimei Fault Chukou Fault Chishang Fault Tainan Xinhua Fault 23 Taitung Kaohsiung Pingtung 22 21 119 120 121 122 123 Figure 5. The type-1 active faults and the grid system of area seismic sources around Taiwan In general, probabilistic seismic hazard analysis (PSHA) involves four steps: The first step is to identify and characterize probable seismic sources in the neighborhood of the study region including probability distribution of location and direction of fault rupture. The second step is to characterize the temporal distribution of earthquake recurrence and to determine the ultimate magnitude in each seismic source. The third step is to select an appropriate ground motion prediction model. The last step is the summation of individual effect due to different seismic sources considering the uncertainties in earthquake location, size and ground motion prediction model to obtain the probability that the ground motion parameter will be exceeded during a particular time period. Table 2. The Contents in the seismic event loss table Scenario ID Annual Occurrence Rate Expected Loss Standard Deviation of Loss 1 v1 L1 σ1 2 v2 L2 σ2 … … … … k vk Lk σk … … … … J vJ LJ σJ 7 309 Based on the results of PSHA, the annual occurrence rate (v k) of each scenario earthquake is obtained. Together with the expected consequences (L k) of each scenario earthquake, they are summarized in a table as shown in Table 1, which is named seismic event loss table and can be used in risk assessment. In practice, given occurrence of a scenario earthquake, the standard deviation and the upper-bound of losses may be determined by experiences and experts' opinions. The distribution of losses may be modeled as a beta distribution with mean equal to the expected loss from scenario simulation [6]. Once the SSD and the PSHA module have been established, various kinds of risk estimates can be calculated from the seismic event loss table as shown in Table 2. For example, let L i,j denote the casualties or losses in region i due to scenario earthquake j with annual occurrence rate v j. The expected annual casualties or losses in region i can be expressed as: ⋅= i ∑ , vLL jji (4) j The seismic sources which contribute more risk to a particular region can also be identified. This is J done by denoting L i as the expected annual loss in region i caused by seismic source J. If there are j scenario earthquakes in the seismic source J, the expected annual loss in region i caused by the seismic source J can be calculated as follows: j J ⋅= i ∑ i,k vLL k (5) k=1 Suppose that there are N scenario earthquakes in total which may cause losses in region i . The N scenario earthquakes have been sorted according to losses induced in region i in descending order, that is, ≥≥≥≥≥ ii 2,1, K ,Ki K LLLL ,Ni (6) The annual occurrence rate for each scenario earthquake has been calculated as v1,…,vN, respectively. According to the definition, the annual occurrence rate with L i ≥ L i,1 is v1; the annual occurrence rate K with L i ≥ L i,2 is v1 + v2. In general, the annual occurrence rate with L i ≥ L i,K is v , which can be expressed as K K = ∑νν j (7) j=1 Assuming the earthquake occurrences are stationary Poisson processes, the annual probability of occurrence of event L i ≥ L i,K can be expressed as () −−=≥ ν K LLP ,Kii )exp(1 (8) The exceeding probability (EP) curves for various kinds of losses can be calculated through Eq. (8). Finally, combining the seismic scenario database and the results of probabilistic seismic hazard 8 310 analysis, one can obtain the seismic event loss table, which can be used to calculate various kinds of risk statistics in different regions or of specific targets. Seismic Risk Assessment of the Water Pipeline System in Taipei Metropolitan Area Figure 6 depicts the spatial distribution of buried water pipeline system in the Taipei metropolitan area. It is operated by the Taipei Water Department (TWD). This system serves the whole Taipei City (including 12 districts) and four other cities of the Taipei County (i.e. Shin-dian, Shan-chung, Yeong-ho and Chung-ho). The total length of the pipeline system is 7,153km (2,435km of large, 1,814km of middle, and 2,904km of small pipelines, respectively). Based on Table 3, the probability of leak or break and the repair cost and man-hours per pipeline damage point [7, 8], the annual pipeline repair number and repair cost of each district/city due to the seismic hazard can be simulated. They are depicted in the left and the right sub-figures of Figure 7, respectively. Similarly, the EP curves of this pipeline system with respect to the total repair number and repair cost of the whole TWD service area are depicted in the left and the right sub-figures of Figure 8, respectively. Figure 6. Water pipelines in the Taipei metropolitan area Table 3. The probability of leak or break and the repair cost and man-hours per pipeline damage point Leaks Breaks Pipe Diameter Probability Cost* Man-hours Probability Cost* Man-hours <65mm 0.3 10 10 0.7 16 10 65-150mm 0.3 80 50 0.7 120 70 150-300mm 0.3 160 90 0.7 240 220 300-500mm 0.3 300 120 0.7 400 400 500-900mm - - - 1.0 780 800 900-1500mm - - - 1.0 960 1,400 >1,500mm - - - 1.0 1,800 2,500 *Cost in thousand NT dollars 9 311 Figure 7. The annual water pipeline repair number (left) and repair cost (right, in thousand NT dollars) of each district / city due to the seismic hazard Figure 8. The EP curve of TWD’s pipeline system with respect to the number of repairs (left) and repair cost (right, in million NT dollars) Application: Maximum Probable Earthquakes for Disaster Reduction Plans Recently, Yeh has investigated the concept of maximum probable earthquakes (MPEs) and applied it to formulating disaster reduction plans [9]. MPEs refer to the strong earthquakes which may result in very severe damages, casualties and losses. Based on data of annual loss estimates and the associated EP curves, it is possible to determine the suitable MPEs in a probabilistic sense. To demonstrate this, we first assume that the TWD should be prepared for a seismic loss in pipelines with a return period of 500 years (about 10% in 50 years), as the Taipei City is the political as well as commercial center of Taiwan, and the people it serves consists of around one fifth of the total population in Taiwan. The corresponding loss is equivalent to 4,000 repairs or 200 million NT dollars according to the EP curves. Such loss could be set as a protection standard to the TWD, based on which the utility disaster reduction plans should be formulated. Under such circumstance, the most 10 312 adequate MPEs can be determined by finding from the seismic event loss table the scenarios with about the same loss yet the highest annual occurrence rate. Since there usually exist more than on option that satisfies the requirements, a selection of at least two MPE scenarios is recommended for increasing the variety of threats, see Figure 9. On the other hand, a seismic loss with a very long return period (say 2,500 years or 2% in 50 years; see Figure 10) is very rare and seems unlikely to take place. Even such loss takes place, the other water utilities in Taiwan are not likely to be seriously affected at the same time. In order to survive such loss, a wiser solution for the TWD is to sign agreement with nearby counties or cities to cooperate and manage disaster together. All parties in the agreement could benefit by avoiding over-investment but staying capable of confronting a very rare seismic event. Figure 9. Two MPE scenarios (based on number of repairs; 10%-in-50-year scenarios) Figure 10. Two MPE scenarios (based on number of repairs; 2%-in-50-year scenarios) 11 313 SUMMARY In this study, the damage data in the 1999 Chi-Chi, Taiwan earthquake have been investigated again. New formulae have been achieved for the seismic repair rate of buried water pipelines considering the combined effect of both ground shaking and deformation. The attained formulae cover a wide range of PGA (up to 700 gals) and ground strain (up to 0.007). These make them very unique when compared with the data from other earthquakes. They can be utilized for water pipeline loss estimation in Taiwan without the need of undesired extrapolation. The Taipei metropolitan area has been employed as a testbed for performing the seismic risk assessment of water pipeline systems. The concept of maximum possible earthquakes has been introduced and applied in formulating utility disaster reduction plans. ACKNOWLEDGMENTS Regarding the Chi-Chi earthquake data, CWB and LSB provided the strong motion records and the GPS measurements, respectively. The Taiwan Water Supply Corporation provided the pipeline blueprints and repair data. Some of them were further digitized, calibrated, and generously provided by Prof. Walter W. Chen and Prof. Che-Hao Chang, National Taipei University of Technology. Without these valuable data, it won’t be possible to conduct this study. Finally, the funding from the TWD under Grant No. 09531065G15 is gratefully acknowledged. REFERENCES [1] Schiff, A. J. and A. K. Tang. 2000. Chi-Chi Taiwan Earthquake of September 21, 1999 – Lifeline Performance, EIC, TCLEE Monograph 18, ASCE. [2] Chang, C.-H., Y.-M. Lin, W. Chen and B.-J. Shih. 2004. “The Damage Ratio Estimation of Water Pipelines Due to Earthquake by Permanent Ground Deformation,” Proc. 3rd Taiwan-Japan Workshop on Lifeline Performance and Disaster Mitigation, Taipei, Taiwan, pp.45-51. [3] Hwang, H., Y.-H. Chiu, W. Chen and B.-J. Shih. 2004. “Analysis of Damage to Steel Gas Pipelines by Ground Shaking Effects during the Chi-Chi, Taiwan Earthquake,” Earthquake Spectra, 20(4):1095-1110. [4] Yeh, C.-H., B.-J. Shih, C.-H. Chang, W. Chen, G.-Y. Liu, and H.-Y. Hung. 2006. “Seismic Damage Assessment of Potable Water Pipelines,” Proc. 4th Int. Confer. Earthquake Eng., Paper No.247, Oct. 12-13, Taipei, Taiwan. [5] Yeh, C. H. 2004. Development of Taiwan Seismic Scenario Database and Its Applications, Proc. Int. Confer. Commemoration of 5th Anniversary of the 1999 Chi-Chi Earthquake, Taiwan, Sep. 8-9, Taipei, Taiwan. [6] Dong, W. 2001. Building a More Profitable Portfolio – Modern Portfolio Theory with Application to Catastrophe Insurance, Reactions Publishing Group. [7] FEMA. 1999. HAZUS 99 Technical Manual Part II, Chapter 7 ~ Chapter 9, Washington, D.C.. [8] Shih, B.-J., C.-H. Yeh and G.-Y. Liu. 2006. Seismic Assessment of Buried Water Pipelines in Taipei, Technical Report for the Taipei Water Department, Fund No. 09531065G15, Taipei, Taiwan. [9] Yeh, C.-H. 2007. “Determination of Maximum Probable Earthquakes in Disaster Reduction Plans,” Proc. 10-th Int. Confer. Applications of Statistics and Probability in Civil Eng. (ICASP 10), Jul. 31-Aug. 3, Tokyo, Japan. 12 314 Emergency measures - a Study of the Fukuoka West Offshore Earthquake Kuniaki Nakamura ABSTRACT Fukuoka city is located in the northern district of Kyusyu Island, and has been said to be one of the safest area among Japan. Nevertheless, a massive earthquake measuring 6-lower of the Japanese Meteorological Agency seismic intensity scale (out of a maximum of 7), the Fukuoka West Offshore Earthquake, occurred on the 20th of March, 2005. Fukuoka City was left dazed and confused due to the lack of knowledge of and preparation for emergency situations. In this paper, I will look into how Fukuoka waterworks responded to the disaster and how it can improve itself for future emergencies. Kuniaki Nakamura, Section Chief, Water Facilities Section, Water Purification Department, Fukuoka City Waterworks Bureau, 1-28-15 Hakataekimae, Hakata-Ward, Fukuoka Japan 812-0011 315 PREFACE Outline of the Fukuoka city Sapporo Sendai Nagoya Hiroshima Tokyo Fukuoka Osaka Figure 1. Location of the Fukuoka Japan consists of four main islands and other small islands, one of which is Kyushyu Island where Fukuoka City is located as shown in figure 1. Fukuoka City, with a population of 1.4million, plays an important role as the gate way to the rest of Asia by providing air and sea connections. Tertiary industry is main one in Fukuoka such as wholesale, retail, restaurant, etc. It accounts for 90% of the all employment in Fukuoka city. Fukuoka airport has the fourth domestic passenger volume in Japan, and Hakata port is designated as one of the key port by the national government. Additionally, Fukuoka City provides further domestic connection by rail and road network Outline of the Fukuoka City Waterworks History Fukuoka city does not have enough water resources due to the topographical condition, which means it is prone to water shortage. An example is the severe drought in 1978, which brought upon a limited supply for 287days. From this experience, we aim to develop water resources and to make the city with water conservation in order to save water in which cost and labor have been invested. 316 Water conservation development As the water conservation development programs, there are three main countermeasures. First, Water supply control system has been in operation since 1981. Supply area in the city is divided into 21 blocks, where electric valves, flow meters and pressure gauges are located. Central monitoring and pressure control system are operated by the Water Control Center. It allows labor saving during droughts, reduces water leakage and adjusts the flow among purification plants. The effects of the water pressure control are shown in figure 2. Secondly, the water leakage investigation is conducted in a suitable circulation period based on observed data. Thirdly, the plan to renew the old pipeline was put into action, consequently ductile iron pipe accounts for over 99% of pipe network. Through the incorporation of these measures, effectiveness rate meaning the proportion of the water that has been used effectively, has stood at over 95% since 1997 Without control Water Pressure With control Restricted Water Supply Severe drought season (Day time) (Night time) Time Figure 2. The effects of the Water Pressure Control 317 FUKUOKA WEST OFFSHORE EARTHQUAKE Outline of the Earthquake Located in the northern part of Kyushu, Fukuoka City was regarded as safe in comparison to other areas of Japan with frequent earthquakes. However, an earthquake of seismic intensity of 6 lower and magnitude 7.0 occurred in Fukuoka on March 20th, 2005. It is the largest ever earthquake recorded since the establishment of the Fukuoka Meteorological observatory. Aftershocks, following main tremor, hit 360 times by the end of May 2005. Main tremor (20／Mar．) Largest aftershock (20／Apr．) The Kego fault ※Circles represents the magnitude of the tremors by 31st May 2005. ※This figure is originated from the Institute of Seismology and Volcanology, Kyusyu University Figure 3. The Epicenters of the Fukuoka West Offshore earthquake 318 Frequency Elapsed days ※ Numbers of earthquakes measuring higher than scale one on the seismic intensity scale ※ quoted from the report on the Fukuoka West Offshore Earthquake by Fukuoka Prefecture Government. Figure 4. Number of West Offshore Fukuoka Earthquakes 20/3/2005～31/5/2005 Damage Due to the Earthquake 1,003 people were injured and one was dead. 141 houses were completely destructed and those in Genkai Island near by the epicenter, which was hit directly by the earthquake, accounted for 107. 5,199 houses were partially destructed or slightly damaged in the whole city. The harbor and the fishing port facilities were heavily damaged, and the total cost of damage to public facilities, including roads and schools cost 24.2 billion yen. The areas with most damage were the areas with a lot of liquefaction, and the areas east of the active Kego fault. Regarding the liquefaction, the area along the seashore has the potential of liquefaction because Fukuoka city has been developed through land reclamation. In fact, the areas damaged by the liquefaction were concentrated on the seashore. With regard to the active Kego fault, there was a lot of damage on the east side of the fault (refer to figure 5). As can be seen in figure 6, the depth of the soft layers on the east side of the fault measures 60m above the deepest bedrock, whereas the depth of the other side measures 20m. As a result, it is guessed that the shock of the earthquake was amplified in proportion to the thickness of the soft layers. 319 K K Damaged buildings Kego fault ※quoted from the 2nd prompt damage survey report by the Civil Engineer Association Figure 5. Plane figure showing location of damaged buildings in downtown area Light damage Heavy damage Hakata Station. Airport Akasaka City Hall Sandy Clay layer Granite Hakata Clay Layer Sandy Gravel Gravel、Sandstone、Shale Kego Fault ※quoted from the report on the Fukuoka West Offshore Earthquake by Fukuoka Prefecture Government. Figure 6. K-K Section（Length/Depth=1/50） 320 Damages to the Waterworks Facilities The key function of the waterworks facilities such as purification plants, conveyance, transmission facilities and distribution basins survived with only minor negligible damages. The damage to distribution and service facilities such as pipes and attached equipment were comparatively heavy in the vicinity of the fault and the coast zone. Concretely speaking, 61 distribution facilities, 101 service facilities in public areas and 1,641 of those in private areas were destroyed or had water leakage. The damages were not as heavy as expected in an earthquake of such a scale. One of the reasons why damages were reduced was the usage of ductile iron pipe with chain type joint to replace old ones in the reclaimed area, where irregular subsidence of land was expected. Sites of facility damage are shown in the figure 7, and as can been seen, damages to facilities are concentrated in the east side area of the active Kego fault and in the latent liquefaction areas. Main tremor Repairing spots of distribution pipe 31 Repairing spots of service pipe within public area 101 配水管等被災状況 Repairing spots of distribution pipe’s appurtenant 30 Kego fault Figure 7. Damages to waterworks facilities 321 Volume of Water Leakage due to the Earthquake The amount of the water supply in the city increased rapidly immediately after the earthquake and it reached a stable state after a while. It is speculated that this is not an influence from the leakage but from the sloshing effect described after. The leak volume is calculated by comparing water supply volume of the day after the earthquake with that of a normal day, both at 4～5 A.M when the water usage is at the lowest. From this, the leak volume due to the earthquake was assumed to be 50,000m3 per day (refer to figure 8). The Sloshing Effects Water supply increased instantaneously after the earthquake and reached a steady level 17 minutes later. This phenomenon of rapid change of the water supply can not be explained by increase in leakage. It seems appropriate to suppose that a lot of water run out all together in a short period of time from the distribution pipe network. The dominant cause is considered the sloshing effect in receiving tanks of buildings. Sloshing induces the ball taps attached in the receiving tanks to malfunction. The figure 8 shows the 24-hour data of the water supply since the earthquake occurred. 24hours data of pressure and flow rate after the earthquake Pressure(MPa) 0.6 After Earthquake Pressure in the rural areas Before Earthquake Pressure in the downtown area Flow rate 0.3 (m3/h) Leak rate Flow rate 0.2 on the earthquake day Flow rate 0.1 on a usual day Elapsed time Figure 8. 24-hour data of water pressure and flow rates after the earthquake 322 Inquiries Fukuoka City Waterworks Customer Center handled inquiries, In addition, the Maintenance Center, which was set up by the Fukuoka pipe work union luckily from 2months prior to the earthquake, took in inquiries of the service facilities in the private area around-the-clock. The above responded to approximately 1,200 cases within 32 hours after the quake. Afterwards calls were also taken at 3 Maintenance Offices and 7 Business Branch Offices. After a month, the total inquiries added up to 2,200, out of which inquiries on service pipe leakage accounted for 80%. Emergency Water Supply An emergency water supply is indispensable to support the disaster victims. Especially hospitals with a dialysis treatment facilities and social welfare facilities for the socially vulnerable should have top priority receiving emergency water supply. However there were no requests for emergency water supply from the above facilities during the disaster. It was fortunate that the waterworks pipe network was slightly damaged during the disaster, so the emergency water supply was only provided to six sites, including Kyusyu Memorial Gymnasium, which was a major evacuation center. Emergency Recovery Ordinarily, the repair system is as follows: The city area is divided to 3 blocks, four units with repair equipment and wireless radio standing by in each block. These units were called upon to repair damages immediately after the earthquake. Meanwhile, the registered repair service companies conducted repair work in private areas. Repair work progressed rapidly, and the volume of water leakage reduce gradually as can been seen in figure 9. The Water Control Center found from water supply data analysis that leaks occurred largely in the central and coastal areas, so it concentrated its repair works in these areas. The Water Control Center greatly assisted in reducing the volume of leakage. 323 Water supply Leak vol. Supply vol. （ｍ３） （ｍ３） Leak Mar． Apr． Figure 9. Leak volume due to the earthquake Victim support Various support measures were provided to the disaster victims, of which the water-related supports provided were specified below 1. Exemption from water charges 2. Leaked volume deducted from the water charge 3. Deferred payment 4. Amount of water used for tank cleaning deducted from the water charge 5. Exemption from service charges RISK MANAGEMENT AFTER THE FUKUOKA WEST OFFSHORE EARTHQUAKE Review of the Earthquake Probability and Scale An investigation in 2001 showed that an earthquake of 6.5-7.1 on the magnitude scale may hit the center of Fukuoka City as a consequence of the active Kego Fault. The recurrence interval of an earthquake was 15,500 years and the probability of an earthquake within 30 years was 0.4%. Fukuoka City Waterworks relied on this 324 investigation in planning its emergency response system. After the earthquake, another investigation is being conducted by Investigation Advisory Committee of Fukuoka City. On the other hand, it has already been announced by the National Earthquake Investigation Committee in March 2007 that the probability of an earthquake of 7.2 on the magnitude scale in the next 30 years is 0.3-6.0%, so Fukuoka City Waterworks has decided to review its existing earthquake response plan with new data. Pipe Construction Connecting Emergency Refuge Bases In the case of a disaster, 300 evacuation centers have been designated by the city authority, including hospitals, schools, public halls and parks. Construction of earthquake-resistant pipes between the core distribution pipes and these evacuation centers should take top priority, especially the pipes in the vicinity of the active Kego Fault, elapsed pipes, and pipes with numerous leaks. Reinforcement of the Cooperation with Other Cities Strengthening the ties among the waterworks bureau of other cities is important in the case of the disasters. If neighboring cities are prepared to provide assistance, supply water to each other in emergencies, and hold joint training sessions, we could be better prepared for an emergency. Fukuoka City Waterworks exchanged memorandum with 15city waterworks bureaus nationwide, and has exchanged memorandum with nine cities in Kyusyu regarding providing assistance in emergencies. Raising Awareness of Emergencies Data clearly shows the changing attitude of the Fukuoka City Waterworks Bureau workers during the earthquake. Three hours after the first tremor on March 20, 25% of the workers were at their desks. Three hours after the largest aftershock on April 20, 45% of the workers were at their desks. This shows that workers became more aware of the emergency situations. In order for the workers to be able to react appropriately in emergencies, it is important to conduct regular simulation training programs, seminars on mutual aid, seminars on established disaster response programs, and emergency assembly training. For the residents, it is important for them to be prepared for water shortage by preparing water containers, being aware of the nearest evacuation center and checking their route to the center. In short, the residents’ awareness must be raised in order to prevent them from being defenseless in emergencies. 325 CONCLUSION Though Fukuoka City was thought to be safe against earthquakes, as can been seen from the heavy earthquake striking Fukuoka, there is nowhere safe against earthquake in Japan. Anti seismic facilities’ constructions are carried on in accordance with the original anti-earthquake plan. However this plan ought to be reviewed in the face of new data of probability of a next earthquake and its scale. Further, as a lesson learned from the earthquake, the emergency response system needs to be improved through training with other waterworks to enhance awareness and management abilities to emergency. Fukuoka City Waterworks is a financially –independent system and income has not been increased in recent years. Though the maintenance cost has tended to be tight due to the budget shortage, it is one of the important missions of our generation to hand over the water supply system with good condition to the next generation. Much more efforts to get enough budget and manpower should be continued patiently and steadily. Water supply system should be kept in a safe and stable condition, seeing that a city cannot withstand disasters without solid social infrastructure, which of course includes waterworks. AKNOWLEDGEMENT First of all, I deeply appreciate both of Fukuoka Waterworks Bureau staffs. Mr. Tooru Yarimizu in the Engineering Administration Section gave various data and reports concerned about the earthquake. Mr. Hideo Kashima in the Water Control Center submitted the data and suggested the contents of this report. Materials they provided were greatly contributed to this report. In addition, I appreciated the staffs of the International Section in City Hall to make the English version report. REFERENCES (1) Fukuoka Waterworks bureau. “Waterworks activity on Fukuoka West Offshore Earthquake” November 2005. (2) Fukuoka Waterworks bureau. “Anti-earthquake plan for waterworks facilities” March 2003. (3) Earthquake Investigation Committee, Fukuoka Pref. Government. “Report on the Fukuoka West Offshore Earthquake ” July 2005. 326 5th AWWARF/JWWA Water System Seismic Conference SESSION 6 EMERGENCY RESPONSE Mr. Ken-ichi Koike, Kanagawa Water Supply Authority, Yokohama, JAPAN – “Water Supply Control and Management in Emergency in the Wide Area Water Supply – Using the Mutual Communication Raw Water Conveyance Facilities” Mr. Michael Ambrose, East Bay Municipal Utility District, Oakland, CA, US – “Multi- Hazard Emergency Preparedness at East Bay Municipal Utility District” Dr. Siao-Syun Ke, National Science & Technology Center for Disaster Reduction, TAIWAN – “The Emergency Response Plan and Preparedness of Water Supply System in Taipei City under Earthquake” Mr. Steve Welch, Contra Costa Water District, Concord, CA, US – “Earthquake Response Planning – Gaining Control of Disaster” Prof. Tatsuo Ohmachi, Tokyo Institute of Technology, Yokohama, JAPAN – “Near-field Earthquake Displacements of the Non-liquefiable Ground Relevant to Damage to Buried Pipelines” 327 328 Water Supply Control and Management in Emergency in the Wide Area Water Supply. Using the Mutual Communication Raw Water Conveyance Facilities Ken-ichi Koike ABSTRACT Kanagawa Water Supply Authority (KWSA) is requested the stability of water supply in case of a disaster such as earthquakes. Our two water resources were connected by the inner diameter 1,650mm raw water transmission main. Since it is effective measure for the water supply control and management of the wide area water supply in the emergency, it introduces as an emergency correspondence. ______Ken-ichi Koike, Section Chief, Division of Water Supply Control and Management, Kanagawa Water Supply Authority (KWSA), 1194 Yazashi-cho, Asahi-ku, Yokohama, Japan 241-0811 329 OUTLINE OF KWSA Kanagawa Water Supply Authority (KWSA) is a bulk water supplier that supplies to the waterworks of Kanagawa Prefecture, Yokohama City, and Kawasaki City and Yokosuka City (hereafter, it is called the constituent bodies of KWSA). KWSA was established in 1969 to supply purified water to these large-scale waterworks and utilize effectively the water resource. The Sakawa River in the western part of Kanagawa Prefecture was developed at the time of foundation (The Sakawa River Intake Project), and the Sagami River (The Sagami River Intake Project) in the center part was developed with construction of Miyagase Dam. These rivers are our main water resources. KWSA has two water intake facilities, four water purification plants, and 40 supply points to supply purified water to the constituent bodies of KWSA. The supply capacity of 2,625,800m3/day is, and the rate of occupying to the total water supply of the constituent bodies of KWSA has became about 50%. One of the water resources of KWSA is different from the water resource of the constituent bodies of KWSA. It plays a major roll in the emergency, so-called, the role of back-up system for the constituent bodies of KWSA as a wide area water supply system. Moreover, the reciprocal connection and the duplex water pipe are positively executed, and it greatly contributes to the stability of water supply. Figure 1. Water Supply Facilities of KWSA 330 MEASURES AGAINST EARTHQUAKE OF KWSA KWSA has designed and constructed for the earthquake resistance since the Sakawa River Intake Project (the foundation project), the anti-earthquake criteria for the water supply [1] revised severe after Hanshin-Awaji (Kobe) Earthquake. According to the criteria, the facility of KWSA correspond to the facilities importance (rank A), request to keep the function of facilities and the minimal damage in case of the ground vibration level (level 2). New facilities are designed based on this latest anti-earthquake criteria, the seismic diagnosis for the existing facilities is executing, and the earthquake resistant reinforcement is sped up especially intake weir, water channel, water pipe bridge, and office building, etc. Seismic Diagnosis z First Seismic Diagnosis (1982) z Seismic Diagnosis for Building (1996) z Seismic Diagnosis for Structure (1997) z Seismic Diagnosis for Raw Water Conveyance Facilities (2000) z Seismic Diagnosis for Other Facilities (1995 - 2004) Earthquake Resistant Reinforcement Building (1998 to 2002) It executes such as the reinforcement with carbon fiber, the installation of bearing wall, power-proof brace and beam and pillars. Aqueduct Bridge and Water Pipe Bridge (1995 to 2004) It executes such as the reinforcement with the ferroconcrete for Sagamigawa Aqueduct Bridge and other water pipe bridges. Water Purification Facilities (2001 to 2004) It executes such as the reinforcement with a restraint joint. Iizumi Intake Weir (2004) It executes such as the reinforcement with a steel board, carbon fiber for the pillars of intake mouse and operators room. Moreover, "Earthquake Resistant Measures Committee" has been inaugurated to investigate and verify the earthquake resistance of current facilities in KWSA. 331 Understanding and Planning for Restoration of Damage Situation Earthquake Based on "Kanagawa Prefecture Regional Disaster Prevention Plan" In the Earthquake Resistant Measures Committee, the seismic diagnosis in the future and the plan of earthquake proof measures are considered, on the other hand, the seismic hazard that influences the water supply of KWSA is specifically assumed, and discuss the water supply control and the restoration plan at the earthquake disaster. This paper is based on the result of committee. INFLUENCE ON FACILITIES AND SCENARIO EARTHQUAKE Scenario Earthquake In "Kanagawa Prefecture Regional Disaster Prevention Plan - earthquake disaster measures plan -" (March, 2005) [2], "The Tokai Earthquake", "The South Kanto Earthquake", "The Western Kanagawa Prefecture Earthquake", "The Miura Peninsula North Fault Earthquake", and "The Kannawa and Kozu-Matsuda Fault Belt Earthquake" are assumed as an earthquake that influences on Kanagawa Prefecture. TABLE I. EARTHQUAKE INFLUENCES KANAGAWA PREFECTURE Name of Earthquake Hypocenter Scale Imminence Tokai Earthquake Suruga Trough 8 Yes South Kanto Earthquake Sagami Trough 7.9 Before for 100 to 200 years South Kanto regional South Kanto Inland Earthquake 7.0 Some degree right under Western Kanagawa Prefecture Western Kanagawa 7.0 Yes Earthquake Prefecture Same fault zone and Kannawa and Kozu-Matsuda Fault Belt Within 100 years in the sea area extension 7.5 Earthquake future including present part Within 100 of years when Miura Peninsula North Fault Earthquake This fault county 7.0 to 7.2 the future including present. The earthquake size is especially "Kannawa and Kozu-Matsuda Fault Belt Earthquake" large, it is as an earthquake with the imminence, and the inner diameter 3,100 mm raw water transmission main that convey raw water from the Sakawa River that is the water resource of KWSA crosses on this fault. The Sakawa River is not intaked by the constituent bodies of KWSA, and it is also an important water resource for the main constituent bodies of KWSA. 332 Kannawa and Kozu-Matsuda Fault Belt Earthquake The Kannawa and Kozu-Matsuda Fault Belt Earthquake has many unidentified things in the seismology, and the investigation of earthquake size and damage were delay. This earthquake was pointed one of three large-scale fault belt earthquakes in the future by Science and Technology Agency in 1997. A quantitative calculation of damage became clear by the investigation report of "Kanagawa Prefecture Earthquake Estimation of Damage Investigation Committee"[3] in 1999. According to the report, the feature of damage is as follows. z Possibility of maximum damage more than the South Kanto Earthquake. z Assumed earthquake with a seismic intensity of 6 in the whole area of Kanagawa Prefecture. z Assumed occurrence of large-scale sediment disaster. z Assumed occurrence of big damage to structures such as Shinkansen and expressways where the fault get across. z Possibility of occurrence of big tsunami. z Possibility of occurrence seismic ground motion with length cycle, and damage in long and big structure. TABLEⅡ. ASSUMPTION OF DAMAGE Kanagawa Kanagawa Kannawa and Assumption Prefecture Tokai South Kanto Prefecture Kozu-Matsuda Item West Earthquake Earthquake East Part Fault Belt Earthquake Earthquake Earthquake Human Suffering Dead 600 230 16,000 2,700 7,600 Seriously Injured 670 1,200 6,400 2,900 6,600 Building Damage Large 33,700 20,100 319,000 95,000 410,000 Middle 68,000 54,200 397,000 258,000 569,000 Fire damage Burnt Down 5,300 2,200 220,000 120,000 － Buildings Damage to the facilities of KWSA in Kannawa and Kozu-Matsuda Fault Belt Earthquake The inner diameter 3,100mm raw water transmission main is the conveyance pipeline to transmit raw water from Iizumi Pumping Station (P.S.) at the Sakawa River to Isehara, Sagamihara, and Nishi-nagasawa Purification plants (P.P.). The Kannawa and Kozu-Matsuda Fault Belt is crossed in about 4.7km point from Iizumi P.S. to Soga Junction Well. In case of the action of Kannawa and Kozu-Matsuda Fault Belt, the raw water transmission to Isehara, Sagamihara, and Nishi-nagasawa P.P. is main water resource is broken and the occurrence of extensive damage is expected. 333 Soga Junction Well Raw Water Transmission Tunnel Kannawa and Kozu – Matuda Fault 3,100mm Raw Water Transmission Main Sakawa River Iizumi 3,100mm Raw Water Transmission Main L = 4,696.25 m Figure 2. Position of Kannawa and Kozu-Matsuda Fault and Inner Diameter 3,100mm Raw Water Transmission Main According to the latest investigation of Kannawa and Kozu-Matsuda Fault Belt Earthquake, the average displacement speed is calculated about 3m in 1,000 years, for there is a gap of about 20m in the stratum of about 6,000 years ago. And the average activity cycle is guessed to be 1,100 years from 1,000 years, therefore the displacement is assumed to be about 3 to 3.3m. Expectation of Damage to Raw Water Transmission Main (Inner Diameter 3,100mm Raw Water Transmission Main) in the Part of Fault If the part of fault moves a few meters, the crossed raw water transmission main is greatly transformed, it breaks in the worst case, and it is likely to leak. Moreover, the expansion pipe at the part of the fault is broken or damaged. In addition, the following are the proactive measures of fault part. z Installation of Pipe for Discharge as Temporary Pipe. z Laying of By-pass with High Density Polyethylene Pipe. However, the width of fault amounts to 600m with congestion, the clear position is not confirmed, and the parallel faults are identified. Therefore KWSA cannot take the proactive measures. 334 Fault 21,500 200 21,000 18,600 15,600 Expansion Raw Water Main Side of Soga Junction Well Expansion Side of Sakawa River Steel Stake Figure 3. Displacement of expansion pipe for inner diameter 3,100mm raw water transmission main in case of fault displacement Expectation of Damage of Other Fault Part The distortion of straight part of pipe is occurred by the seismic ground motion, the maximum distortion of 0.064% in the seismic ground motion level 2 is, and it is safe compared with the permissible distortion of 0.336%. Expectation of Damage of Raw Water Transmission Main by Liquidizing The stratum composition of this region has the clay layer, sandy soil, and gravel bed, and liquidizing is caused easily. However, it is not easy to think liquidizing to the whole line of raw water transmission main road, and there is no damage because of surfacing of the pipe. INFLUENCE WATER SUPPLY There is a possibility that the inner diameter 3,100mm raw water transmission main is broken when the fault acts by the Kannawa and Kozu-Matsuda Fault Belt Earthquake. The restoration period is settled on aiming within one week on the basis of "Earthquake-Proof Plan Decision Guidance for Water Supply"[4] (January, 1997), when the breaking or the functional maintenance of raw water main becomes impossible. KWSA set the emergency restoration plan and maintain the stockpile. However, it is necessary to control and management water supply in the emergency, for the raw water transmission to Isehara, Sagamihara and Nishi-nagasawa P.P. can not work during the emergency restoration. When the stockpile for the emergency restoration is unavailable, the 335 emergency correspondence for 160 days is requested as temporary restoration, for 190 days as complete restoration. The supply points to supply purified water from three purification plants of Sakawa River Water System to the constituent bodies of KWSA, which have not the backup system such as reciprocal connection transmission pipe will hold the risk of water suspension. The amount of water of each purification plant that has not the backup systems in Sakawa River Water System is shown in Table Ⅲ. These many supply points have not the backup systems and the buffer such as the distribution reservoir etc, directly supply purified water to the customer. When the raw water transmission is cut by the breaking of inner diameter 3,100mm raw water transmission main, there is strong possibility of the water suspension in the early stage. It is guessed that the influence of water suspension reaches as much as 960,000 households in Kanagawa Prefecture. The avoidance of water suspension to 960,000 households is the obligation of KWSA at the earthquake occurrence. It is requested to secure the water of 546,100m3/h that is an impossible to intake from Iizumi P.S. TABLE Ⅲ TRANSFER OF EACH PURIFICATION PLANT IN SAKAWA WATER SUPPLY SYSTEM Available Transfer Not Available Transfer Supply Area of to another water resource to another water resource Purification Plant (m3/D) (m3/D) Isehara Purification Plant 14,400 81,500 Area Sagamihara Purification Plant Area 100,300 198,300 Nishi-nagasawa Purification Plant Area 111,000 266,300 Total 225,700 546,100 Make from application for amount of water from each constituent bodies of KWSA in 2006. OPERATION OF 1,650mm INNER DIAMETER RAW WATER MAIN IN EMERGENCY Outline of Operation of Inner Diameter 1,650mm Raw Water Main The inner diameter 1,650mm raw water transmission main was constructed for the stability of water supply in the center of Kanagawa prefecture by the Sagami River Intake Project. It connects the raw water transmission tunnel from the Sakawa River and Shake P.S. to intake raw water from the Sagami River, and it has the role of the mutual communication raw water conveyance facilities. There are two kinds of operations for the inner diameter 1,650mm raw water transmission main. On the one hand, the amount of water flow from the Sagami River to the purification plants in Sakawa River Water System (Isehara P.P., Sagamihara P.P., Nishi-nagasawa P.P.) is the maximum of 12,000m3/h by the pumping. (hereafter, it is called the Regular Raw Water Transmission). On the other hand, the amount of water flow from the Sakawa River to the direction of Sagami River purification plant (Ayase P.P.) is maximum of 9,000m3/h by the gravity. (hereafter, it is called the Inversion Raw Water Transmission) Additionally, the Inversion Raw Water Transmission can be a raw water transmission with the pumping discharge by Ayase Lines Pumping Facilities in Shake P.S. 336 it can convey raw water from the Sakawa River and the Sagami River to the direction of the Sagami River purification plant (Ayase P.P.) (It is called the Combined Raw Water Transmission) The test run begun in 2005, and the official operation in 2006. By the completion of these facilities, even if one of the water resources suffers caused by a water shortage and a water quality accident, it is possible to supply from the other safety water resource, and the backup function in the emergency will be achieved. The connecting point of this raw water transmission main to Sakawa River Water System is Isehara Junction Well in Isehara P.P., where is situated on about 20km the downstream of inner diameter 3,100mm raw water transmission that crossed Kannawa and Kozu-Matsuda Fault Belt. Therefore, by using the 1,650mm inner diameter raw water transmission main, even if the inner diameter 3,100mm raw water transmission main breaks the cause of Kannawa and Kozu-Matsuda Fault Belt Earthquake, the water supply from the Sagami River to the purification plants in Sakawa River Water System (Isehara P.P., Sagamihara P.P., Nishi-nagasawa P.P.) is possible, and the risk of the water suspension can be reduced. Regular Raw Water Transmission (Shake P.S. → Isehara Junction Well → IseharaP.P., Sagamihara P.P. & Nishi-nagasawa P.P.) The way of raw water transmission is usually operate and transmit raw water from the Isehara Pumping Facility at Shake P.S. to the filtration plants in Sakawa River Water System. z Specification of Isehara Line Pumping Facility Flow Rate 84m3/mim, Total Head 69m, Rotational Speed 985rpm, Motor Output 1,300kW, 2units z Specification of the 1,650mm raw water transmission main Ductile Iron Pipe (U type, L=7,839.33m) Coated Steel Pipe (STW400, L=1,145.71m) z Specification of Isehara Junction Well> RC, 1Stories Below, Diameter10.40m, Depth 56.24m Inversion Raw Water Transmission (Iizumi P.S. → Isehara Junction Well → Ayase P.P.) This way of the raw water transmission is operate in case of accident. The amount of transmission raw water depends on the amount of one from Iizumi P.S. It conveys raw water to Ayase P.P. by the gravity. Combined Raw Water Transmission (Iizumi P.S. → Isehara Junction Well → ) Ayase P.P. Ayase Line Pumping Facility → This way of the raw water transmission conveys raw water from Iizumi P.S. with Ayase Pumping Facility at Shake P.S. to Ayase P.P. z Specification of Ayase Line Pumping Facility Flow rate 139m3/mim, Total Head 49m, Rotational Speed 575rpm, Motor Output 1,500kW, 4units 337 Sakawa River Water System Isehara P.P. Sagamihara P.P. Nishi-nagasawa P.P. 3,100mm Raw Water Transmission Main P.S. Mutual Communication Raw Water Conveyance Facilities Iizumi P.S. Ayase P.P. Sakawa River P.S. Shake P.S. Sagami River Water System Sagami River Figure 4. KWSA Facilities System Water Supply Control and Management in Case of Kannawa and Kozu - Matsuda Fault Belt Earthquake The supply points that have not the backup systems such as inter-connecting pipe in Sakawa River Water System are 17. Isehara Line Pumping Facility at Shake P.S. is able to supply to 10 supply points that can not be supplied from the other water resources in emergency situations. And 7 supply points in the Nishi-nagasawa P.P. supply area can be supplied from the other water resource. Therefore, it is possible to avoid the water suspension to Isehara P.P. and Sagamihara P.P. The amount of the Regular Raw Water Transmission, because the number of installation of Isehara Line Pumping Facility is two units, even 288,000m3/d is possible under the present situation. However, it is necessary to supply the amount of water 546,100m3/d to avoid the water suspension for 17 supply points that have not the backup function in Sakawa River Water System, therefore the Regular Raw Water Transmission of the present specification can not correspond to avoid the water suspension for all supply points. Nishi-nagasawa P.P. can be supplied the raw water from Numamoto Dam that is the water resource of Sagami River System by the 2nd Raw Water Tunnel. Therefore, a part of the supply point that is supplied from Nishi-nagasawa P.P. is possible the evasion of water suspension in the emergency by just the Regular Raw Water Transmission of present specification. The breakdown of transfer of water in three purification plants in Sakawa River Water System is shown in the TABLE Ⅴ. 338 Numamoto Dam 2nd Raw Water Tunnel Isehara P.P. Sagamihara P.P. Nishi-nagasawa P.P. Fuchinobe Junction Well 3,100mm Raw Water Transmission Main Isehara Junction Well Mutual Communication Raw Water P.S. Conveyance Facilities Iizumi P.S. Sakawa P.S. River Shake Ayase P.P. P.S. Sagami River Figure 5. Supply Raw Water from 2nd Water Tunnel TABLE Ⅴ. BREAKEDOWN OF TRANSFER OF EACH FILTRATION PLANT IN SAKAWA RIVER WATER SYSTEM Raw water transfer to Transfer by Regular Supply Area of another water Raw Water Purification Plant resource Transmission (m3/D) (m3/D) Isehara P.P. Area 81,500 0 Sagamihara P.P. Area 198,300 0 Nishi-nagasawa P. P. Area 0 266,300 Total 279,800 266,300 339 AFTERWORD Even if the inner diameter 3,100mm raw water transmission main in Sakawa River Water System is broken by the Kannawa and Kozu-Matsuda Fault Belt Earthquake, the restoration period is required at least about one week. It is assumed that the raw water transmission from Sakawa River Water System is cut during the restoration period. In this case, all amount of the water suspension is expected to be reaching about 50 percent or more of all amount of waters supplied from KWSA, and an influence on 960,000 households. The operation of existing mutual communication raw water conveyance facilities can back-up about half, and the remainder should depend on another water resource. Another water resource for backup is the allocation of water rights of other water supplier including the constituent bodies of KWSA, and it needs to elaborately adjust. Furthermore it is absolutely essential that the flexible operation which is not fixed on the existing water rights in a large-scale earthquake like this case. In this paper, it is assumed that the inner diameter 3,100mm raw water transmission main in Sakawa River Water System is broken by the Kannawa and Kozu-Matsuda Fault Belt Earthquake, and the supply to the constituent bodies of KWSA stagnates. It describes that the water supply control and management as large area water supply try to evade the water suspension by the Regular Raw Water Transmission with the mutual communication raw water conveyance facilities and the transfer to another water resource. If Isehara Line Pumping Facility at Shake P.S. installed more, the continuation of supply for purification plants in Sakawa River Water System would be possible without the transfer to another water resource. REFERENCES [1] JWWA. 1997. “Anti-earthquake Criteria for Water Supply,” [2] Kanagawa Prefectural Government. March, 2005. “Kanagawa Prefecture Regional Disaster Prevention Plan - Earthquake Disaster Measures Plan,” [3] Kanagawa Prefecture Earthquake Estimation of Damage Investigation Committee. 1999. “Kanagawa Prefecture Earthquake Estimation of Damage Investigation,” [4] Ministry of Health, Labour and Welfare. January, 1997. “Earthquake-Proof Plan Decision Guidance for Water Supply,” 340 Multi-Hazard Emergency Preparedness at East Bay Municipal Utility District Mike Ambrose and Steve Frew ABSTRACT The East Bay Municipal Utility District (EBMUD) is a large water and wastewater utility in the eastern part of San Francisco Bay Area in California. EBMUD operations are exposed to a number of hazards. As such, the District has experienced a number of emergencies and developed an extensive emergency preparedness program. This paper provides an overview of emergency preparedness at EBMUD including significant events that impacted the development of the program, how emergency preparedness and business continuity are handled within the organization, the emergency response organization, specific facilities and equipment dedicated to emergency response, and future initiatives to bolster existing programs. Mike Ambrose, Manager of Regulatory Compliance, Operations and Maintenance Department, East Bay Municipal Utility District, 375 Eleventh Street, MS 704, Oakland, California, USA 94607-4240 Steve Frew, Manager of Security and Emergency Preparedness, Operations and Maintenance Department, East Bay Municipal Utility District, 375 Eleventh Street, MS 409, Oakland, California, USA 94607-4240 341 INTRODUCTION Background The East Bay Municipal Utility District (EBMUD or the District) is a water and wastewater utility based in the eastern part of San Francisco Bay in northern California. EBMUD is a publicly owned utility created in 1923 to provide water service. In 1944, EBMUD's Special District No. 1 was created to treat wastewater discharged into the Bay. EBMUD's water system serves approximately 1.3 million people in a 331-square-mile area (see Figure 1). The wastewater system serves approximately 642,000 people in an 88-square-mile area [1]. About 90 percent of EBMUD's water supply comes from the Mokelumne River watershed in the western slope of the Sierra Nevada Mountains. The watershed covers an area of 627 square miles. Water is transmitted 90 miles to the East Bay via 3 steel aqueducts. The remaining 10 percent of water supply originates as runoff in watersheds in the East Bay [1]. The water service area encompasses incorporated and unincorporated areas in two counties. The City of Oakland is the largest entity served with a population of nearly 400,000. The western portion of the service area is a plain running north-south along the Bay. The Oakland/Berkeley Hills rise to about 1900 feet above sea level and run roughly through the middle of the service area from north to south. Much of the central, hilly portion of the service area is undeveloped watershed lands of EBMUD’s local reservoirs. Urban land uses in the service area include residential (low density single family homes and multi-family residences), commercial, and industrial development. The District employs approximately 1900 people. The District’s Administration Building has about 800 employees and is located in downtown Oakland. There is a large maintenance facility in Oakland. The Main Wastewater Treatment Plant is located at the edge of San Francisco Bay in west Oakland. Other occupied and unoccupied facilities are scattered throughout the East Bay and along the aqueducts up to the Mokelumne Watershed. Hazards Due to the extent of operations and the diverse areas served, EBMUD is exposed to a number of hazards including: • Earthquake • Tsunami • Wild land and urban wild land fires • Flood • Freezes • Terrorist events • Cyber crime • Pandemic 342 Figure 1. EBMUD Service Area 343 Earthquake is the biggest threat due to the expected probability and potential for extensive damage. A total of 5 faults cut through the District’s service area (See Figure 2). The Hayward fault is the most active and has the potential to cause the most damage. The fault runs north-south along the Oakland/Berkeley Hills. There is a 32 percent chance of a magnitude 6.7 or greater quake on the Hayward fault before the year 2030 [2]. Figure 2. Faults in EBMUD Service Area (Courtesy of USGS) 344 DEVELOPMENT OF EMERGENCY PREPAREDNESS AT EBMUD Oakland Hills Fire On Saturday October 20, 1991, a small fire erupted in the Oakland Hills. The Berkeley Fire Department quickly doused the fire. However, hot winds from the east fanned a hot spot into flames again on Sunday morning. The fire burned for several days, destroying 3354 single family homes and 456 apartments, injuring 150 people, and killing 25 persons. More than 1600 acres were burned at a cost of $1.5 billion. It was the worst residential fire in California history [3]. After the fire, the District created an Office of Emergency Preparedness and hired the first Emergency Preparedness Officer in 1992. A group of employees were designated to the Emergency Operations Team (EOT) and a comprehensive emergency operations plan was developed. The EOT was trained on the plan and exercises simulating disasters were completed. EBMUD also led the formation of a permanent organization called the Hills Emergency Forum consisting of East Bay agencies, counties, and cities to reduce the potential for another firestorm. The group assessed hill area fire hazards, and developed fire-related codes, ordinances, equipment needs, and training exercises. The District also created the Water Agency Response Network (WARN) with water agencies in 16 coastal counties. The WARN created an omnibus mutual aid agreement to help respond to emergencies like the firestorm. The WARN program was expanded to agencies all over the state. Standardized Emergency Management System During the Oakland Hills fire, the home of State Senator Nick Petris was destroyed. Consequently, Senator Petris introduced legislation directing the California Governor's Office of Emergency Services (OES) to establish the Standardized Emergency Management System (SEMS) [4]. The framework of SEMS includes the Incident Command System (ICS) and the Multi-Agency Coordination System (MACS). SEMS is required by California Government Code for managing emergencies involving multiple jurisdictions and agencies. Local governments must use SEMS to be eligible for funding their response-related personnel costs under state disaster assistance programs. SEMS is intended to facilitate the flow of information within and between levels of the system, and coordination among all responding agencies. The intent of SEMS is to improve the mobilization, deployment, utilization, tracking, and demobilization of needed mutual aid resources. SEMS is designed to be flexible and adaptable to the varied disasters that occur in California and to the needs of all emergency responders. ICS is a basic function of SEMS. The intent of ICS is to create an emergency management system that is organizationally flexible to meet the needs of incidents of any kind and size; able to use the system on a day-to-day basis for routine situations as well as for major emergencies; and sufficiently standardized to allow personnel from a variety of agencies and diverse geographic locations to rapidly meld into a common management structure. MACS is a system that allows agencies and organizations to coordinate response to several incidents, allocate critical resources, and share information. 345 National Incident Management System After the September 11, 2001 attacks on the World Trade Center and the Pentagon, the U.S. Government sought a comprehensive national approach to incident management that was applicable to all jurisdictional levels and across disciplines. The intention was to improve coordination and cooperation between public and private entities in a variety of domestic incident management activities including acts of terrorism, wild land and urban fires, floods, hazardous materials spills, nuclear accidents, earthquakes, hurricanes, etc. On February 28, 2003, the President issued Homeland Security Presidential Directive 5 (HSPD-5), which directed the Secretary of Homeland Security to develop and administer a National Incident Management System (NIMS). According to HSPD-5, the goal of NIMS is to provide a consistent nationwide approach for Federal, State, and local governments to work effectively and efficiently together to prepare for, respond to, and recover from domestic incidents, regardless of cause, size, or complexity. The NIMS includes a core set of concepts, principles, and terminology covering the incident command system; multiagency coordination systems; unified command; training; identification and management of resources; qualification and certification of personnel; and the collection, tracking, and reporting of incident information and incident resources to provide for interoperability and compatibility among Federal, State, and local entities. EBMUD has incorporated SEMS and NIMS into all emergency preparedness policies, plans, training, and exercises. EBMUD EMERGENCY PREPAREDNESS PROGRAM FEATURES Emergency Preparedness/Business Continuity Policy The District has a policy on emergency preparedness and business continuity to ensure an active Emergency Preparedness Program is implemented in accordance with the guidelines of the NIMS and SEMS to help manage the District's critical functions during any emergency and protect the safety of staff. The policy also supports a business continuity program to minimize disruptions of critical business functions and enhance recovery operations following an event that causes a business interruption. The policy defines a District emergency, describes the purchasing authority of the General Manager in the event of an emergency, management succession, and the Emergency Operations Director (EOD). The EOD may direct all human or material resources of the District to combat the effects of a threatened, declared or actual emergency. Emergency Preparedness Staff Two staff members are dedicated full-time to emergency preparedness and security. The District hired a Security Operations Officer in 2002 to centralize security operations at the District. This position was combined with the Emergency Preparedness Officer and changed to the Manager of Security and Emergency Preparedness. The Manager of Security and Emergency Preparedness plans, develops, evaluates, and manages District-wide security operations and emergency preparedness and response programs. 346 A Security and Emergency Preparedness Specialist works under the direction of the Manager of Security and Emergency Preparedness. The Specialist implements and maintains assigned elements of the District’s security operations, emergency preparedness, and business continuity programs including developing emergency plans, training District staff, developing and implementing exercises of emergency plans, completing after action reports, and coordinating with outside agencies. Emergency Operations Plan The District’s Emergency Operations Plan (EOP) outlines the District's overall emergency management program for response to natural disasters and malevolent acts. The plan is designed to help the District organize, manage, respond, and recover quickly and effectively. The plan identifies potential hazards, explains activation of the plan, describes the Emergency Operations Team organization, identifies responsibilities during disaster response, and gives guidance on emergency preparedness including education and training. Emergency Operations Team The Emergency Operations Team (see Figure 3) identified in the EOP is staffed by EBMUD employees. The team is lead by the Emergency Operations Director as per District policy. The Emergency Operations Director receives legal authority and guidance from a Policy Group which is comprised of the Board of Directors, General Manager and a Legal Advisor from the General Counsel’s Office. The group is organized in accordance with NIMS and SEMS (i.e., a Command Staff, which includes the Director of Emergency Operations, a Safety Officer, a Regulatory Compliance Officer, a Liaison Officer, and an Administrative Scribe; and a General Staff, which consists of the Operations, Planning, Logistics, and Finance Sections). A primary, alternate and backup employee for each EOT position has been identified to ensure sufficient staff can initially respond and two 12-hour shifts can be implemented during the emergency. Training and Exercises Using SEMS and NIMS is an efficient way to respond to, work through and recover from an emergency incident, but it does require a detailed process, proper forms to document planning and response, and coordination between responders. During a fire, a water utility may simply serve as an advisor or liaison from the utility to a fire incident commander to assist with necessary water supply. This is a relatively easy role to fill for most water agencies. However, when an incident like a regional earthquake occurs, or when a water district like EBMUD loses a major facility due to fire, flood, or some other emergency, our response planning must include all such potential hazards. Training staff to be competent in managing an emergency using the same (SEMS/NIMS) system that fire and police agencies use, certifying key staff as emergency supervisors and managers, and practicing a coordinated response with other agencies takes a significant commitment. In California, all emergency response personnel must be trained in the SEMS. At EBMUD, all employees are deemed to be Disaster Service Workers as per California law, so all new employees receive an overview of SEMS as part of their orientation to the District. 347 EBMUD Board of Directors POLICY GROUP General Manager Legal Advisor Emergency Operations Director Operations Planning Logistics Finance Section Section Section Section Figure 3. Emergency Operations Team The Federal Government under the Department of Homeland Security (DHS) has developed national standards for training in emergency management (i.e., NIMS). NIMS certification is required to receive DHS grant funding. Field emergency response personnel, supervisors and managers all receive specific training and certificates to prove that they are competent at the necessary levels. Depending on the role the employee fills, this training could cover anywhere from one day to a week or more. To meet this requirement, the District has staff trained and certified as trainers to deliver the training at the required levels to the EOT and emergency response staff. Once trained, the District exercises this training at least twice each year. The District participates in a statewide exercise called Golden Guardian each fall, and conducts another exercise, usually in concert with other first responder (police/fire) agencies and with local, regional or state Offices of Emergency Services. Coordination with Other Agencies and Government Since 1991, fire agencies in the East Bay meet and work closely with EBMUD through the East Bay Hills Fire Forum to continually improve our working relationship and preparedness to respond to a fire in the Oakland Hills area. These meetings help fire agencies understand the District’s distribution systems, and is critical to coordinating our efforts during firefighting in their areas. The California Utilities Emergency Association (CUEA) is located at the Office of Emergency Services State Operations Center (SOC) in Sacramento. The CUEA provides 348 structure for efficient communications and coordination among government agencies and public and private utilities throughout the state. CUEA is the contact point for emergency managers representing all types of utilities in California including water, wastewater, energy (gas and electric), and telecommunications, and petroleum pipelines. CUEA provides a network to discuss emergency preparedness issues with other utilities. CUEA also serves as the primary contact for all utilities in the state during a regional emergency. Formed shortly after September 11, 2001, the Bay Area Security Information Collaborative (BASIC) is a network of Security and Emergency Preparedness professionals who work for the 9 larger water utilities, both public and private, around the San Francisco Bay Area, as well as the California Department of Health Services (CDHS) and the Environmental Protection Agency (EPA). This group meets regularly to discuss security and emergency preparedness issues of concern. BASIC has developed a potable water distribution plan for the State of California, to assist the Office of Emergency Services following a regional earthquake. The purpose of the plan is procure and distribute water to the public when water treatment and distribution facilities are not functional due to damage. BASIC has also developed a forum to communicate and assess response to any increase in the local, regional or national threat level as defined by the Department of Homeland Security. The Water Agency Response Network (WARN) is a network developed by EBMUD, to connect water agencies in California with one-another when they need resources in an emergency. Through this web-based network, a water or wastewater agency can offer or obtain necessary resources such as an emergency generator, portable pump, forklift or operators. Through the network, the resource can be requested as a mutual aid/assistance resource, from one water agency to another. This concept has been expanded to several other states across the U.S. District security staff have been trained in a course called the Terrorism Liaison Officer (TLO) by the East Bay Terrorism Early Warning Group (EB TWEG). The EB TEWG is a group of law enforcement officers and deputies from the two counties in the EBMUD service area. TLO’s are cleared to receive confidential information from law enforcement that may impact District operations. District staff provide the EB TEWG information on potential terrorist activities. Investigators take such data from all agencies in the region to compare notes and identify patterns. Facilities and Equipment The District has a dedicated Emergency Operations Center (EOC) in its Administration Building in downtown Oakland. The EOC is located adjacent to the operations control center for the water distribution system. The EOC provides work stations for the Emergency Operations Team, computer terminals, analog telephones, printers and plotters, fax machines, and satellite telephone and ham radio communications to facilitate information sharing, satellite TV monitors to track developing news from multiple sources at one time. The District recently procured a Mobile Command Post Vehicle using $120,000 in grant funding from the Department of Homeland Security. The vehicle is a 28 foot trailer, equipped with 6 networked workstations, a conference room, satellite receiver and monitor, Telular® telephones, satellite phones, fax machine, kitchenette, restroom and storage. It is designed to work alongside police/fire or any other emergency response agency in unified or joint command 349 of an emergency event, and gives the District the ability to manage a prolonged event in comfort regardless of location or weather conditions. The District has equipped Incident Bases (IB’s) at key facilities. The IB’s house personnel and equipment to support operations at multiple incident sites. The IB’s can activate on their own or under the direction of the EOC. This gives EBMUD the ability to manage large-scale response regionally as well as functionally, and to ensure continuity of operations to the highest degree possible during the response and recovery period. Business Continuity Program As important as its response to an emergency, the District must be able to ensure its ability to maintain its critical business functions and recover important business functions to support employee care, customer needs, financial services, legal responsibilities and regulatory issues following an emergency or disaster. To meet this demand, each department has developed a Business Continuity Plan (BCP) that outlines the critical functions that must be performed before, during and after an interruption, the personnel responsible for completing the necessary actions, and the records, equipment and systems required to accomplish the identified tasks. The departments are responsible to ensure that the BCPs are maintained, employees trained, and the vital records necessary to maintain operations are available. FUTURE ELEMENTS OF THE EMERGENCY PREPAREDNESS PROGRAM Alternate EOC An alternate EOC is currently in the design phase. The District’s Administration Building that contains the EOC is subject to damage from a major earthquake. The building has been structurally upgraded, but it may not be occupiable following a severe event. The District will construct an alternate EOC with limited capabilities at a facility east of the Oakland/Berkeley Hills. The probability is that a single event will not damage both facilities, and the District will have the ability to manage emergencies at different EOC locations. Alternate Data Center The District has a data center in its Administration Building that supports the Information Technology (IT) needs of the entire District. Information systems including communication systems (phone, email, and internet) and access to specific network applications like work management, materials management, and electronic timesheets are high priority systems with recovery time objectives ranging from 12 to 72 hours. The existing data center is susceptible to fires, insider threats, and earthquakes. Consequently, the District entered an agreement with a similar agency in Sacramento, the Sacramento Municipal Utility District, to share some space in each other’s data center. In addition, a study of other alternatives is being completed that would provide a more robust solution for a greater number of District applications. 350 Emergency Response Plans As a supplement to the EOP, several Emergency Response Plans (ERPs) are being developed that provide general strategies for responding to specific events. ERPs for a failure of a raw water aqueduct, an earthquake west of the Oakland/Berkeley Hills (probably a Hayward Fault event), and a pandemic have been drafted. ERPs are planned for an earthquake east of the Oakland/Berkeley Hills and a water quality event. Mutual Assistance EBMUD has negotiated an agreement with the Los Angeles Department of Water and Power for providing mutual assistance in the event of a disaster that effect one, but not the other agency. As large water utilities that work in a similar fashion, such an agreement provides these agencies the ability to obtain significant staff and equipment resources through one agency, and to deploy them quickly. The District has begun discussing expansion of this agreement to other large water and wastewater utilities in the Western United States. REFERENCES [1] Jain P., E. Szczepankowska, and J. Tam. November 2005. “Urban Water Management Plan 2005,” East Bay Municipal Utility District. [2] Working Group on California Earthquake Probabilities 1999. Earthquake Probabilities in the San Francisco Bay Region: 2000 to 2030 – A Summary of Findings, U.S. Geological Survey, Open-File Report 99-517. [3] McClendon, I. 1999. “Its Name Was M.U.D., A Story of Water,” East Bay Municipal Utility District: 261-267. [4] SEMS Guidelines, Standardized Emergency Management System, September 2006. 351 352 The Emergency Response Plan and Preparedness of Water Supply System in Taipei City under Earthquake Ban-Jwu Shih, Siao-Syun Ke, Wei-Sen Li, and Pei-Chung Hsu ABSTRACT In Taipei City with more than 2.5 million populations, earthquake is one of common natural threats to public infrastructures and utilities. Tap water supply system containing huge and complicated underground pipelines is the fundamental infrastructure of urban city. For increasing the post-quake survival and function of modern city, evaluating and strengthening of the seismic capacity in existing water supply system will contribute to improving daily safety. Besides introducing the emergency preparedness of water supply system in Taipei , this paper estimates the population be affected and emergency quantity of water to prepare after earthquake in metropolitan Taipei City according to damage estimation of the water pipeline system and population distribution. And base on the losses estimation, the countermeasures and strategies of emergency response will be designed to make fundamental suggestions toward pipeline system under major earthquake attack. INTROCTION Water supply system containing complex and huge underground pipelines is the important and fundamental infrastructure of urban city. But water supply system is vulnerable to earthquake damage and difficult to be examined and repaired fast after the earthquake. Even the function of the overall system be stopped to work cause of some damages on partial pipelines or facilities. The damages on the water supply system not only caused the inconvenience of major people in the disaster area but also delayed the disaster rescue, such as water shortage would delay the post-earthquake fire rescue or injure sanitation in disaster areas, resulting in the spread of infecting diseases. Therefore, it’s necessary for safety of the city to improve the post-earthquake emergency response capacity of the water systems. Based on the “The plans of Taipei district disaster prevention and rescue (2005)”, the post-earthquakes emergency response and preparedness of water supply should be planned by Taipei Water Department (referred to as TWD) in duty. “Water Supply Project Taipei Area Tap-Water 5th Phase Construction”[1]（hereinafter referred to as Taipei Water 5th Project）is a project proposed by Taipei Water Department and approved by the Executive Yuan in 1991, for satisfying the water demand of Greater Taipei Area till 2030 as well as the safe and steady supply of water and water ______Ban-Jwu Shih, Associate Professor, Department of Civil Engineering, National Taipei University of Technology, No.1, Sec. 3, ChungHsiao E. Rd., Taipei City 106, Taiwan, Siao-Syun Ke, Assistant Researcher, National Science and Technology Center for Disaster Reduction, 9F., No.200, Sec. 3, Beisin Rd., Sindian City, Taipei County 231, Taiwan. Wei-Sen Li, Associate Researcher, National Science and Technology Center for Disaster Reduction, 9F., No.200, Sec. 3, Beisin Rd., Sindian City, Taipei County 231, Taiwan. Pei-Chung Hsu, Secretary general , Water Works Association of the Republic of China (Taiwan), 7F., No.106, Sec. 2, ChangAn E. Rd., Taipei City 104, Taiwan. quality. However, it has been more than a decade since Taipei Water 5th Project was established, there are quite some difference in water supply and demand from the basis of earlier planning. In 1 353 order to fulfill the needs in water supply up to 2030, promote safety of water supply system, establish system backup and capacity reservation mechanism and divide into Water Supply Zones for effective management, TWD hence review the execution of Taipei Water 5th Project and drafted the basic planning of the subsequent project to be the baseline for the continuous project of Taipei Water 5th Project. Besides introducing the emergency preparedness of water supply system in Taipei, this paper estimates the population be affected and emergency quantity of water to prepare after earthquake in metropolitan Taipei City according to damage estimation of the water pipeline system and population distribution. And base on the losses estimation, the countermeasures and strategies of emergency response will be designed to make fundamental suggestions toward pipeline system under major earthquake attack. THE EMERGENCY PREPAREDNESS OF WATER SUPPLY SYSTEM IN TAIPEI CITY UNDER EARTHQUAKE In recent years, the water supply frequently be suspended in Taiwan due to various natural disasters. In view of this, Taipei Water Department actively improved the disaster prevention and rescue based on three strategies : strengthen facilities, emergency restoration, and emergency water supply. TWD also improve the plans to avoid or reduce damage cause of any possible factors endangering the safety of water supply such as the earthquake, the drought, the rainstorm, the high raw water turbidity and the facilities accident, etc. For satisfying the water demand of Taipei metropolitan as well as the safe and steady supply and quality of water when water supply facilities damaged after earthquakes, Taipei Water Department in recent years actively strived for emergency preparedness and related trainings in the following sequence: Upgrade the Capacity of Purification Plants The 5th and 6th purification facilities be added in Zhitan purification plant. In addition to supply Taipei County, improve reserve rate of the purification plant from 0.6% up to 29%. TWD also improve safety and stability of regional water supply by adding four boost stations in service area. Upgrade the Capacity of the Support • The establishment of the second running-water main pipeline forms the double-pipeline water supply system with the first running-water main pipeline. It can substantially improve the stability and safety of water supply in Taipei. Moreover, the second raw water transportation pipeline is under construction. It will also be served as spare system at the abnormal situation of the first raw water transportation pipeline or at annual service and maintenance in the future. • The double power supply system be set up in each purification plant and large-scale boost stations. And rented generators in reserve be set up in mid-scale and small-scale boost stations. 2 354 Strengthen Capability of the Water Supply System Besides the annual maintenance of the first running-water main pipeline and the first raw water transportation pipeline, TWD actively replaced the old or leaking pipelines and comprehensively installed the new pipes used for seismic resistance material such as the flexible stainless steel pipe. And water supply zones be divided for effective management. Improve Capacity of Emergency Water Supply 13 emergency water supply points including 11 points located in the boost stations and 2 points located near running-water main pipeline (shown as figure 1) have be currently set in Taipei metropolitan. The total volume of reserving water is about 220,000 tons and 2.4 million residents can be supplied 30 days based on the daily requirement of 3-liter per person. Adding emergency water supply points located near running-water main pipeline be mainly planned in future. TWD has two running-water main pipelines with 2,400 mm in diameter and total length of main pipelines is about 34km. Besides, the total length of branch pipelines with 2,000 mm in diameter is about 5.6 km. The storage water in the main pipelines and branch pipelines can be provided for post-disaster emergency water supply in full or partial suspension. 17 points have been planned by TWD and the location be chose based on the following conditions : • Located near existing airing valves or working wells. • Enough space to set up the temporary water supply equipment. • Located near main traffic line or shelters. In addition, 12 seismic resistance storage tanks in disaster-prevention parks and 22 temporary water supply points formed with stainless steel buckets, water supply vehicles and temporary hydrants have been planned. Figure 1. Emergency water supply points located near running-water main pipeline (printed by Taipei Water Department). 3 355 Promote Popular Capacity of Emergency Response Taipei Water Department promoted popular capacity and willingness of emergency response through various public disaster drills that residents directly participate and practically operated facilities. And TWD regularly investigated the opinion of populace about the demand of post-earthquakes water supply including daily consumption and quality of water. The results will be helpful to improve the plans about disaster prevention and emergency response. TWD also provided related information for disaster prevention to the populace by the publicity containing operation descriptions of facilities, locations of the emergency water supply points and procedures for emergency water supply, etc., shown in figure 2. Figure 2. The publicity printed by Taipei Water Department ANALYSIS OF THE EMERGENCY WATER SUPPLY IN TAIPEI METROPOLITAN Taipei Water Department supplied 4 million people in Taipei metropolitan with tap water of 3.1 million tons per day. Safety, health and convenience are three important goals for TWD. After earthquakes, TWD had distributed the tap water to the residents in disaster area in duty. To estimate the demand for emergency water supply, this paper estimates the affected population, the quantity of emergency water supply, working-hours and manpower for repair according to the basic statistical data such as population in each district, population density, number of households, pipeline density and the scale of earthquake (return period of 500 years). And base on the result, the countermeasures and strategies of emergency response will be designed to make fundamental suggestions toward pipeline system under major earthquake attack. 4 356 Analysis of Distribution of the Population in the Service Area of Taipei Water Department The service area of Taipei Water Department covers with 16 districts which 4 districts (SanChong city, YongHe city, JhongHe city and SinDian city) are part of Taipei County and 12 districts are part of Taipei City. Based on the latest population statistics (October, 2006)[2], the population in each district were between 200,000 to 300,000 except DaAn (over 300,000 people), NanGong, DaTong, ZhongShan and WanHua (less than 200,000). The current average population density of Taipei City were 9,667 people per square kilometer. Because of the difference in geographical conditions and development , the population density of every districts were not equal, more than 27,000 people per square kilometer in DaAn but less than 5,000 people per square kilometer in BeiTou, ShiLin and SinDian for example. The detail is shown in Table 1 and Figure 3. TABLE 1. POPULATION DISTRIBUTION IN THE SERVICE AREA OF TAIPEI WATER DEPARTMENT Population Area Population number of District density ( km2 ) (person) households (person/ km2) SongShan 9.29 208,788 22,480 75,646 XinYi 11.21 230,943 20,606 84,934 DaAn 11.36 313,628 27,605 113,784 ZhongShan 13.68 219,091 16,013 86,950 ZhongZheng 7.61 158,393 20,822 59,496 DaTong 5.68 126,901 22,336 45,349 WanHua 8.85 194,652 21,989 72,271 WenShan 31.51 260,863 8,279 93,027 NanGang 21.84 112,992 5,173 38,992 NeiHu 31.58 264,154 8,365 90,114 ShiLin 62.37 287,918 4,616 96,713 Beitou 56.82 249,151 4,385 84,951 SanChong 16.32 383,524 23,505 128,920 YongHe 5.71 235,407 41,200 86,889 JhongHe 20.14 410,203 20,364 145,046 SinDian 120.23 288,495 2,400 109,075 Total 434.20 3,945,103 16,883 1,412,157 5 357 Beitou Beitou ShiLin ShiLin NeiHu NeiHu ZhongShan ZhongShan SanChong Da To n g Da To n g SanChong SongShan SongShan ZhongZheng Na n Gong ZhongZheng Na n Gong Xi nYi Xi nYi WanHua Da An WanHua Da An YongHe Popul at i on YongHe densi t y JhongHe WenShan WenShan Unit:person/km^2 JhongHe Popul at i on Un i t ： p e r s o n > 40,000 > 400,000 > 20,000 > 300,000 Si nDi an > 10,000 Si nDi an > 200,000 > 5,000 < 200,000 < 5,000 Figure 3. Population distribution in the service area of Taipei Water Department The Estimation of the Affected Population and the Amount of Emergency Water Supply after the Earthquake Based on the repair rate of water pipelines, the dry rate and affected population after earthquake could be estimated preliminarily. In this paper, the local formula of repair rate referring to large GIS databases compiled after 1999 Chi-Chi earthquake in Taiwan be adopted[3].This empirical formula be obtained by the approach of regression considering the effects of ground shaking and permanent ground deformation simultaneously. The estimation of the affected population were shown as table 2. However, the rate of aged people (more than 65 years old) and youth people(less than 14 years old) is higher in JhongHe city, SanChong city, DaAn, WenShan and SinDian city. Therefore, more temporary water supply points should be set in these districts and emergency water bags with suitable capacity should be designed. Meanwhile, in accordance with the restoring rate of water supply and the required quantity per person per day, the total quantity of emergency water supply within 10 days after the earthquake can be estimated. This paper assumed that the required quantity of water per person is 3-liter within 4 days, 10-liter on 5th day, 12-liter on 6th day, 16-liter on 7th to 9th day and 20-liter on 10th day after the earthquake[3]. According to the demand, the total quantity of emergency water supply is about 6,000 tons on the first day. And 1,200 vehicle trips will be dispatched based on the carrying capacity 6 358 of the vehicle of 5-ton. The daily required quantity of water supply within 10 days after earthquake is shown as Table 3. The peak quantity of water supply will be on the 5th and 10th day. Therefore, the vehicle scheduling must to be planned in advance. But the daily water supply for unaffected residents still have to be considered. TABLE 2. AFFECTED POPULATION AFTER EARTHQUAKE Affected < 14 15-64 > 65 District population years old years old years old (person) (person) (person) (person) SongShan 102,185 18,538 71,766 11,881 XinYi 122,811 19,028 88,743 15,041 DaAn 162,895 27,831 113,529 21,535 ZhongShan 107,189 16,115 78,521 12,553 ZhongZheng 82,162 15,009 56,265 10,888 DaTong 63,388 9,921 45,596 7,871 WanHua 102,683 14,382 73,898 14,404 WenShan 141,634 25,930 100,761 14,943 NanGang 55,010 9,244 40,197 5,569 NeiHu 120,259 22,957 87,967 9,335 ShiLin 111,835 18,033 81,651 12,150 Beitou 94,537 15,973 68,738 9,826 SanChong 213,725 35,920 161,866 15,940 YongHe 115,214 19,374 84,951 10,888 JhongHe 227,948 34,154 175,855 17,939 SinDian 156,131 23,876 117,491 14,764 total 1,979,605 326,284 1,447,795 205,526 TABLE 3. THE ESTIMATION OF REQUIRED QUANTITY AND VEHICLE TRIPS WITHIN 10 DAYS AFTER EARTHQUAKES District 1st day 2nd day 4th day 5th day 6th day 7th day 10th day SongShan 307 252 207 656 750 956 1,053 XinYi 368 303 249 788 902 1,150 1,266 DaAn 489 402 330 1,045 1,196 1,525 1,679 ZhongShan 322 264 217 688 787 1,003 1,105 ZhongZheng 246 203 166 527 603 769 847 DaTong 190 156 128 407 465 593 653 WanHua 308 253 208 659 754 961 1,058 7 359 WenShan 425 349 287 909 1,040 1,326 1,460 NanGang 165 136 111 353 404 515 567 NeiHu 361 297 243 771 883 1,126 1,240 ShiLin 336 276 226 717 821 1,047 1,153 Beitou 284 233 191 606 694 885 974 SanChong 641 527 433 1,371 1,569 2,001 2,203 YongHe 346 284 233 739 846 1,078 1,188 JhongHe 684 562 461 1,462 1,674 2,134 2,349 SinDian 468 385 316 1,002 1,146 1,461 1,609 Total 5,939 4,882 4,007 12,699 14,536 18,529 20,404 Vehicle trips 1,188 977 801 2,540 2,908 3,706 4,081 The Estimation of Manpower for Repair after the Earthquake The Estimation of Working Hours for Repair The total working hours for repair of water pipelines in each diameter should include excavation, drainage, replacement of the pipe, washing the pipe and restoring water supply and was shown in table 4 [4]. But working hours may be added because of the special environment, damages on the traffic lines and other reasons. TABLE 3. THE REQUIRED WORKING HOURS FOR REPAIR OF PIPELINES IN EACH DIAMETER Diameter Working hours for repair Working hours for replace < 65 mm 10 (person-hour) 10 (person-hour) 65mm~150mm 50 (person-hour) 70 (person-hour) 150mm~300mm 90 (person-hour) 220 (person-hour) 300mm~500mm 120 (person-hour) 400 (person-hour) 500mm~900mm 800 (person-hour) 900mm~1500mm 1,400 (person-hour) > 1500mm 2,500 (person-hour) The Estimation of Manpower for Repair To distribute the existing manpower effectively, the required manpower in each district should be estimated further based on the estimation of working hours. In this paper, the repair efficiency be analyzed according to 282 data about the repair of pipelines on database established by Taiwan Water Corporation after Chi-Chi earthquake. Each datum included that how many manpower and working 8 360 hours be cost in each damage on pipelines. This paper assumed that the repair efficiency equal manpower divided by working hours. Therefore, the estimation of required manpower in each district could be counted based on the average repair efficiency and the required working hours in each district. However, the actual manpower for repair of pipeline must be adjusted from the estimation because the loss of the existing manpower caused of earthquakes should be considered. Therefore, the actual required manpower equal the estimation multiplied a factor. This safety factor was tentatively set at 1.25 in this paper. The estimation of actual required working hours and manpower in each district was shown in table 5. TABLE 5. THE REQUIRED WORKING HOURS AND MANPOWER IN EACH DISTRICT Working hours (hour) Total District Diameter (mm) Working <65 65-150 150-300 300-500 500-900 900-1500 >1500 manpower hours SongShan 1,232 777 1,585 689 995 889 2,187 8,354 1,392 XinYi 1,823 1,121 1,400 705 502 2,321 0 7,872 1,312 DaAn 2,760 1,518 2,025 871 1,361 4,981 5,048 18,563 3,094 ZhongShan 2,727 1,226 1,861 942 2,642 1,756 3,095 14,250 2,375 ZhongZheng 1,841 987 1,245 1,128 2,420 2,000 3,910 13,531 2,255 DaTong 2,011 506 734 569 1,097 306 0 5,223 870 WanHua 2,285 752 1,029 573 1,555 348 2 6,543 1,091 WenShan 2,536 1,479 1,696 766 1,440 698 2,168 10,784 1,797 NanGang 867 476 1,020 533 1,150 218 0 4,265 711 NeiHu 1,306 870 1,794 1,174 1,488 1,026 0 7,657 1,276 ShiLin 3,093 1,441 1,754 720 2,305 815 1,199 11,327 1,888 Beitou 2,254 1,103 1,523 1,854 303 2,010 0 9,047 1,508 SanChong 2,458 1,885 2,251 1,834 1,280 1,606 8,173 19,487 3,248 YongHe 2,934 1,118 2,145 949 1,200 1,336 0 9,680 1,613 JhongHe 2,620 1,591 2,108 881 1,650 1,156 1,927 11,933 1,989 SinDian 1,957 920 978 465 850 253 1,566 6,988 1,165 Total 34,704 17,768 25,148 14,651 22,238 21,719 29,274 165,502 27,584 The Estimation of required quantity in each emergency water supply point The affected population and restoring rate of water supply must be considered to estimate the daily vehicle trips per day per Li ( the government organization under the district ). The carrying capacity of 5 tons of each vehicle used for water supply is fixed, but the population serviced by each vehicle is different by the day, each vehicle can supply about 1,300 people within 4 days, 500 people 9 361 on the 5th day, 400 people on the 6th day and 250 people after the earthquake for example. The detail is shown as table 6. TABLE 6. THE AVERAGE AFFECTED POPULATION AND REQUIRED VEHICLE TRIPS PER LI BY THE DAY 1st day 2nd day 4th day 5th day 6th day 7th day 10th day District No. of Li (person) (person) (person) (person) (person) (person) (person) SongShan 33 3,097 2,545 2,089 1,986 1,895 1,811 1,596 XinYi 41 2,995 2,462 2,021 1,922 1,833 1,752 1,544 DaAn 53 3,073 2,526 2,074 1,972 1,881 1,798 1,584 ZhongShan 42 2,552 2,098 1,722 1,637 1,562 1,493 1,315 ZhongZheng 31 2,650 2,179 1,788 1,700 1,622 1,551 1,366 DaTong 25 2,536 2,084 1,711 1,627 1,552 1,483 1,307 WanHua 36 2,852 2,345 1,924 1,830 1,745 1,669 1,470 WenShan 39 3,632 2,985 2,450 2,330 2,222 2,125 1,872 NanGang 19 2,895 2,380 1,953 1,857 1,772 1,694 1,492 NeiHu 37 3,250 2,672 2,193 2,085 1,989 1,901 1,675 ShiLin 51 2,193 1,803 1,479 1,407 1,342 1,283 1,130 Beitou 42 2,251 1,850 1,519 1,444 1,377 1,317 1,160 SanChong 119 1,796 1,476 1,212 1,152 1,099 1,051 926 YongHe 62 1,858 1,528 1,254 1,192 1,137 1,087 958 JhongHe 93 2,451 2,015 1,654 1,572 1,500 1,434 1,263 SinDian 69 2,263 1,860 1,527 1,452 1,385 1,324 1,166 Average 2,647 2,175 1,786 1,698 1,619 1,548 1,364 Average vehicle trips 2 2 2 4 4 6 6 per day per Li CONCLUSION Taipei Water Department has planned the locations of the post-disaster emergency water supply points. This paper provided the quantitative results in required quantity, working hours, manpower and vehicle trips, etc. However, currently the capacity of emergency response and preparedness of TWD may not be enough to handle disaster prevention and rescue. Therefore, we suggested TWD to improve the emergency response plan and preparedness of water supply system reference to the quantitative results in this paper. Furthermore, TWD should send the information about the emergency response and preparedness to residents actively through various media. 10 362 REFERENCES [1] Website of Taipei Water Department, http://www.eng.twd.gov.tw/english/Construction/latest.asp. (in Chinese) [2] Website of Department of Civil Affairs, Taipei City Government, http://www.ca.taipei.gov.tw/civil/page.htm. (in Chinese) [3] “ The study on the seismic vulnerability function for water pipelines in Taipei metropolitan (2006),” Report, National Center for Research on Earthquake Engineering, Taiwan. (in Chinese) [4] “Reconnaissance Report on Earthquake in Taitung on April 1, 2006,” Report, National Science and Technology Center for Disaster Reduction, Taiwan. (in Chinese) 11 363 364 EARTHQUAKE RESPONSE PLANNING – GAINING CONTROL OF DISASTER Walter J. Bishop, Thomas J. Linville, Stephen J. Welch Contra Costa Water District INTRODUCTION The Contra Costa Water District (CCWD, District) provides raw and treated water service to over 550,000 customers in Contra Costa County, California. Its primary water conveyance system is a 70-year old, 85-kilometer long, open, concrete lined canal which serves two CCWD water treatment plants, and various cities, municipalities, industries and agricultural customers. In 1994, following the Loma Prieta and Northridge earthquakes, CCWD undertook a comprehensive seismic assessment of its water conveyance, treatment and distribution systems. The study focus was to identify strategic improvements throughout the CCWD system to minimize water service interruption after a maximum credible earthquake. The study identified over $185 million (2007 U.S. dollars) of improvements required in the system, including improvements to existing pumping and piping, as well as construction of additional pumping, piping and canal improvements. Over the last decade CCWD has implemented various improvements to complete the important task of readying its water conveyance, treatment and distribution system for earthquakes. Nevertheless, CCWD realizes that the threat of major earthquake or other natural or manmade damage is ongoing, and therefore prepares for such events and the necessary response. This report describes how lessons learned from past disasters such as the Northridge and Loma Prieta earthquakes in California, and the Hurricane Katrina disaster in Louisiana, United States can better prepare response teams for disaster response and recovery following a major disaster. CCWD’s critical event for planning purposes is a major earthquake, but the response plan is applicable for terrorist or natural disasters alike. This report summarizes key lessons learned from past disasters, and presents a framework for a response plan based on these lessons. The report also provides an overview of the importance and key aspects of training and practice for emergency response, as well as outlines the importance of re-evaluating the emergency response plan, and incorporating updates and new lessons to ensure that the plan is current and responsive. OUTLINE OF CONTRA COSTA WATER DISTRICT CCWD was established in 1936 to provide water to the central and northeastern regions of Contra Costa County, California. CCWD headquarters is in Concord, California, approximately 56 kilometers east of San Francisco, located in Central Contra Costa County, one of the fastest growing counties in California. (See Figure 1) 365 Figure 1 – Vicinity Map CCWD draws its water from the Sacramento-San Joaquin Delta under a contract with the U.S. Central Valley Project (CVP). As part of the CVP, the 85-kilometer Contra Costa Canal was built in 1937. By means of the canal, water is diverted from Rock Slough (13-kilometers east of Antioch, California) through a 7-kilometer unlined channel into a 78-kilometer concrete-lined canal. Four stations lift water 37.8-meters above sea level to the canal's Antioch summit, after which gravity flows the water to its terminus in Martinez. The canal runs through Oakley, Antioch, Pittsburg, Concord, Walnut Creek, Pleasant Hill, Pacheco, ending at a terminal reservoir in Martinez, California (see Figure 2). 366 Contra Costa Water District Service Area Map Figure 2 – CCWD Service Area CCWD has 4 raw water storage reservoirs: Martinez, Contra Loma, Mallard, and Los Vaqueros, totaling a storage capacity of 1,233,487-litres (103,070 acre-feet). It also has two treatment plants; the Ralph D. Bollman Water Treatment in Concord, with a capacity of over 300 million litres per day; and the Randall-Bold Water Treatment Plant in Oakley, with a capacity of 200 million litres per day. CCWD is also in the process of constructing a new water treatment plant in Brentwood, California with an initial treatment capacity of 60 million litres per day. Roughly half of CCWD customers receive treated water directly from CCWD, the remaining from 6 local agencies who treat and distribute CCWD water. Today, Contra Costa Water District serves a population of over 550,000 and includes treated water distribution facilities with 33 pump stations, 45 storage reservoirs, and 1,252-kilometers of pipelines. CCWD is managed by a General Manager appointed and governed by a 5-member, publicly elected, Board of Directors. CCWD’s 325 employees serve customers that include the municipalities of Antioch, Pittsburg, Brentwood and Martinez, commercial and industrial companies, agricultural entities, and the residential communities of Clayton, Concord, Pleasant Hill, and Walnut Creek The greatest challenge CCWD faces today is continuing to provide high-quality water with an ever-increasing customer demand in an environment with an extremely limited water supply. Such increasing demands are continuously increasing the consequences of damage from an 367 earthquake or other disaster, further increasing the importance of CCWD’s duty to provide reliable water. CCWD is committed to ensuring adequate water resources, high water quality, and reliability for the present and future, particularly in times of emergency. LEARN FROM THE PAST CCWD has had a long interest in being well prepared for emergency response. The District has had several smaller level emergencies over the past several years, such as extended power outages, but has not had to respond to a significant event. However, CCWD has studied the response of others for major events such as the California Northridge and Loma Prieta earthquakes, and more recently, the Hurricane Katrina disaster in Louisiana. In fact, CCWD sent considerable resources to the Hurricane Katrina disaster recovery in an effort to not only assist those in need, but bring back meaningful disaster recovery lessons for use at CCWD. Each disaster has its own specific intricacies. Every effective emergency response plan should be prepared with this understanding in place to ensure the plan includes flexibility. Study of past disasters and the ensuing response allows a plan provider the opportunity to leverage off past lessons to ensure a plan provides the overall breadth of thinking necessary to ensure the plan is inclusive, yet flexible. In studying past disasters, CCWD has identified the following key difficulties in response: • The ability to communicate is greatly reduced. Almost all disasters place a significant strain on communication infrastructure. Not only is there the direct impact of the disaster on facilities such as utility poles, wires, underground infrastructure, towers and electronics, but there is the added “crisis” communication demand on the systems. Communications systems “lock-up” from the added demand on a damaged system. Response by other public services then face the added difficulty of responding without normal levels of communication. This fact increases the need and importance of pre- planned response without normal communication. • Contacts with outside support agencies and resources are difficult to establish. In the above noted disasters, the United States Federal Emergency Management Agency (FEMA) was the primary federal support agency. In addition, local state Office of Emergency Services (OEM) support was available at the state level. The support from these agencies tends to be slow. In the case of Hurricane Katrina, the response was significantly slower than other past U.S. disasters, and possibly resulted in the loss of lives, and increased hardship to the victims. Any emergency response plan must focus on self-sufficiency as reliance on outside agencies and resources is unpredictable, and very likely insufficient. • Transportation systems are greatly restricted. Roads and bridges, railways, traffic signals, and vehicle inventory itself is almost always greatly impacted by disasters. In the event of an earthquake, it is a good assumption that many bridges will be damaged beyond safe use, thereby blocking normal thoroughfare. In the case of Katrina, there was also the added impact of major flooding (an over 4 meter high storm surge) which almost entirely destroyed the vehicle inventories of most the response agencies, and impacted the private and commercial supply. The lesson for an emergency response plan is that movement of people and supplies will be greatly limited. Response plans need to consider this result by pre-staging supplies and people in strategic locations. 368 • Power distribution is unreliable. Similar to the damage to communications, power distribution through poles and underground is vulnerable to many forms of natural and man-made disaster. Given that so much of business and infrastructure is tied to electrical power, loss of this utility has a significant impact to response. Utilities generally have some redundancy for power, and core systems have been hardened for loss of power. Though not as integral to the response as communication and transportation (assuming the primary systems requiring power have redundant supply), loss of power for a long period of time needs to be a part of response planning. The impact to living conditions such as lighting, heat and ventilation, computers and communication equipment must be considered with any response plan. • Monetary supply is greatly reduced; ATM and credit cards do not work, and cash is limited. Banks and financial institutions are closed in the early stages of the emergency response. Even if stores are open, they generally only take cash. An effective emergency response plan needs to consider the ability to transact for services and supplies in the absence of electronic financial institutions and services. • Commerce is greatly reduced. Not only is there the direct impact of materials, supplies and distribution (stores and transportation) being damaged and destroyed, but there is a shortage of individuals willing to conduct commerce. Individuals provide immediate support to their families. The result is that even if commerce has the infrastructure in place to function, staffing and other resources necessary to conduct business are greatly reduced. Because everyone is busy meeting basic needs, there is less availability of resources for infrastructure recovery. • Safety and Security is a greater concern than normal. Unfortunately, though most people respond in a time of crisis by greater generosity, caring and giving, some individuals look at disasters as an opportunity to prey. In the above events studied, all the disasters had significant incidents of looting, theft, and even physical harm. Given the above noted impacts, police, fire and military response is greatly hampered immediately following the event. The emergency response plan should keep this fact in mind, and ensure responders will be safe and secure. Threats from crime, as well as safety impacts such as downed power lines, leaking hazardous materials and chemicals, and structural damage risks, all should be a part of response planning. Using these impacts as guidelines, an effective emergency response plan should prepare a response that addresses the impacts, yet allows for flexibility necessary to respond to variations. The plan should consider necessary actions, responsibilities and assignments, needed resources (both human and physical), needed information, and the overall organization of a response. PREPARING THE PLAN As with any plan, an emergency plan needs to be prepared with the end purpose in mind. The purpose of an effective emergency response plan is to provide the necessary framework to direct an effective response to various likely emergency situations. The plan is not only the guideline for actual emergency response, but also the template for developing and facilitating training and practice as well . It needs to outline who is responsible for what, and provide an overall structure in the possible chaotic response following the emergency event. An effective emergency response plan contains the following key elements: 369 • Purpose of the plan clearly defined; • Definition of key resources (staff, supplies, equipment, including checklists); • Definition of key responsibilities of responders, including any contract support response; the plan should define the default responsibilities (standing orders) in the event of no defined leader; • Definition of expectations for responder preparation (for example, supplies that should be on hand, home preparation, equipment needs); • Response staging areas (locations) clearly defined; • Organization chart (including any back-up assignments); • Any necessary forms, or standard procedures (for example building inspection procedures and forms). Knowing the variety of difficulties likely to be faced in an emergency (as identified above), the plan should include consideration of the following objectives. • Be prepared to be self-sufficient, and include provisions for o Repair parts and supplies o Fuel, power, oils o Water, food, shelter, safety supplies and equipment o Personal care items: towels, toothpaste, sunscreen, etc… o Pre-contracted response support (for example fuel) o Drinking water o Safe and secure housing o Basic medical care, shots, medicines • Develop redundant, reliable communications o Satellite phones o Low band radios o Walkie-talkies o Reporting structure for physical person-to-person contact o Establish pre-determined meeting locations and protocol • Be prepared for a reduced work force - employees will take care of themselves and family first o Develop plans for addressing employee family needs (possible shelter, food and water) o Employee phone “hotline” for assignments and response information o Standing orders for employee response (possibly staggered over time) o Contracts in place for additional support o Pre-planned prioritizations to assist operations with less staff Note: In the Hurricane Katrina event, emergency response staffing was often as low as 20- percent of normal staffing. Staff fled the disaster with their families, and did not return for emergency response. Such low response is not likely in an earthquake response as there will be no lead time to flee the disaster, but an employer should prepare for a moderate level of absenteeism immediately following an earthquake event. 370 • Pre-plan compliance with local, state and federal response requirements and guidelines o Be a signatory to any state or regional office of emergency services compacts, mutual response plans or agreements o Plan with state or regional emergency services offices, practice response with exercises that dovetail with these agency protocols o Pre-plan with state or regional emergency services for water and food distribution to key locations for employee assistance o Develop emergency assistance agreements with similar agencies (agencies out of the area provide redundant support that possibly will not be impacted by the disaster) • Pre-plan business system continuity – electronic commerce will not function or be accepted o Keep enough cash on hand and secure for response for critical needs o Ensure procurement accounts are in place and active for purchase of critical needs (repair parts, materials, fuel, response supplies) o Provide adequate identification (for example, procurement cards) o Assure billing can be issued to customers and payment accepted The above key elements are consistent needs for each emergency response. Ensuring these elements are addressed in the plan, and are consistent with the purpose ensures a workable structure for a response. TRAIN AND PRACTICE One of the significant benefits of any emergency response plan is its value as a foundation for training and practice. The plan not only becomes a solid starting point for training and practice, but then can also be the memory of the practice exercises through continuous modifications and updates. As the response team uses the plan for exercises, lessons learned from the practice sessions then are recorded in the plan through modifications to the plan. Needs such as a different organization, additional or different team members and responsibilities, resources (both human and physical), shelter, and equipment can be identified and addressed. Each agency and each event will clearly require its own specific response (as noted above, the reason the plan should ensure a framework that includes flexibility.) However, there are a few key aspects of training and practice that should be included in development of exercises. • Develop practice scenarios that simulate likely actual conditions during the emergency response (for example loss of power, loss of communications, etc…) • Practice actual deployment of resources (for example delivery and hook-up of emergency power) • Keep mapping and reference information organized, easily accessible (including ability to print in the absence of primary power) and current • Keep phone lists (for example home and cell numbers) current with regularly (monthly) updates and distributions 371 • Conduct actual table-top exercises on a regular basis (quarterly); strengthen key team members through exercises specific to these team member responsibilities (emulate pressure as much as possible) • Form sub-teams in the response team to practice key responsibilities (for example records research, or power deployment, etc…) • Keep exercises practical, applicable and realistic. Exercises need to focus on creating as much of the actual demands and pressure of a foreseeable actual event • Lessons learned from each exercise should be defined, summarized and recorded for future response improvement • Keep the emergency response plan current. The plan should be updated at least annually, and all key lessons learned from exercises should be incorporated into the plan to ensure the plan is continuously improving and adjusting to the changing organization and environment. While practice provides the best approach to simulating the actual emergency response, improving the skills of responders, and learning lessons for future improvement, training outside of practice is also important to ensure that industry-wide lessons and advancements are incorporated into the emergency response plan. In looking for training opportunities, training should include: • Study recent disasters and responses, and inform response team members of the key lessons learned • Send key response team members to assist in response of actual emergencies, battle test the team. Ensure lessons learned by these response team members are incorporated into the emergency response plan • Develop contacts outside the area, and send team members to these contact training exercises, seminars and conferences • Attend federal, state and regional training opportunities, and ensure the latest information is incorporated into the emergency response plan • Ensure key managers are trained in standard response approaches (for example the State of California Standardized Emergency Management System), as well as the specific customized response of the emergency response plan • Bring experienced responders and trainers (individuals with actual experience leading and responding to an emergency) to assess the emergency plan, develop exercises based on this plan, and oversee practice sessions. Through continuous practice and training in the use, development and revision of the emergency response plan, an agency ensures it will be as prepared as possible for the actual emergency, whether large or small. By looking outside the organization as well, the agency in addition can ensure it makes use of the most recent knowledge available for effective response. CONCLUSION The threat of disaster is present for almost every major urban area in the world. The result is that almost all utilities face a future need to respond to an unplanned emergency event. The importance of gaining control of conditions to speed recovery following a disaster is the primary responsibility for any organization charged with the public’s well being. CCWD plans for this primary duty by continuously studying the lessons of past disasters, formalizing response plans, and practicing and training staff for effective response in the face of pressure and confusion 372 This report provided an overview of lessons CCWD has learned from past disasters. The report provided an overview of how a utility can develop a response plan to gain control of disaster level conditions as quickly and as effectively as possible. The report identified how effective plans can be prepared by focusing on response objectives such as: • Communications • Outside Support • Transportation • Monetary Supply • Ability to Carry out Commerce • Safety and Security Additionally, in meeting the above objectives, an effective response plan needs to include consideration and planning for key elements such as: • Purpose of the plan • Key resources • Key responsibilities • Expectations • Response locations • Organization • Forms and procedures Response plans need to also be sure responders have prepared: • To be self-sufficient • Develop redundant, reliable communications • Work with reduced work force • Compliance with regional, state and federal response requirements • Business system continuity An added value of the response plan, beyond providing the framework for the actual response, is the fact that the plan is a template for practicing effective response as a team. Practice is an essential aspect of a response plan to ensure the team is familiar with the plan and its application, and has opportunities to test and “fine tune” the plan. And, while practicing the response plan assists the team improve its likelihood of success in an actual response, training to advance the team in the lessons of the latest emergency response practices and information also is an important aspect of readying for disaster. Lessons learned from past disasters, other industry experts, and internal experience are critical in ensuring a response plan that is comprehensive, yet flexible for unpredictable events and resulting conditions. Identifying the lessons of past disasters and addressing those lessons in a plan with clearly identified objectives is the first step in a successful disaster response. A response plan that incorporates the above discussed approach in its development is not going to eliminate the problems and pressures of a disaster response, but it will ensure a working and comprehensive framework to gain control of the multitude of unforeseen conditions following a major disaster. The result is an organization ready to make a difference when the public needs such leadership and stewardship the most. 373 REFERENCES 1. Contra Costa Water District, “Water Facility Supply and Reliability Improvement Strategy – Development of Seismic and Reliability Criteria Final Report – Volume 1,” August 1994 2. Contra Costa Water District, “Seismic and Reliability Improvements Project, Volume 2”, September 1996 3. Contra Costa Water District, “Seismic and Reliability Improvements Project, Volume 3”, September 1996 4. Contra Costa Water District, “2002 Treated Water Master Plan Update, Final Report”, December 2002 5. Contra Costa Water District, “Hurricane Katrina Disaster Response Assistance and Recovery,” June 2006, AWWA 2006 Annual Conference and Exposition 6. Contra Costa Water District, “Emergency Operation Plan”, August 2006 7. Contra Costa Water District, “Engineering Response Plan”, December 2006 8. U.S. Department of Homeland Security, “National Incident Management System”, March 2004 374 Near-field earthquake displacements of the non-liquefiable ground relevant to damage to buried pipelines Kimiyasu Ohtake, and Tatsuo Ohmachi ABSTRACT The damage to buried water supply pipelines in the non-liquefiable ground caused by the 1995 Hyogoken-Nanbu earthquake was first compared with calculation results from relevant seismic codes showed that damage occurred even if there was a margin of safety factor of about 2. The earthquake-induced displacement of the non-liquefiable ground was next evaluated using results from survey, strong motion observation and numerical simulation in the near-field of the 1995 earthquake. It was found that the dynamic displacement and the permanent displacement were significant not only on the surface layer but also at the engineering bedrock. ______Kimiyasu Ohtake, Engineer, Nippon Jogesuido Sekkei Co., Ltd. 7-20-9, Nishi-Gotanda Shinagawa, Tokyo Japan 141-0031 Tatsuo Ohmachi, Professor, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama Japan 226-8502 375 INTRODUCTION Following the 1995 Hyogoken-Nanbu earthquake, better known as the Kobe earthquake, the Level 2 (L2) earthquake motion has been introduced in seismic design of civil engineering structures. The L2 motion addresses input motions of extremely high intensities like that experienced in Kobe City during the 1995 earthquake. Among various seismic design codes, those for buried pipelines of such as water supply, sewage water, and high pressure gas were also revised after the 1995 earthquake, with a main focus on introduction of the L2 motions［1］. As a result, intensity of the seismic design spectra of velocity on the engineering bed rock was upgraded to about 4 times as large as the previous ones, as shown in Figure 1. Most parts of the seismic codes except the design spectra, however, were kept the same as the previous codes. For example, the revised codes also apply the so-called seismic deformation method, which has traditionally based on an assumption that ground displacement on the engineering bed rock is negligible during earthquakes, and that the earthquake-induced ground displacement associated with the damage to pipelines is produced in the surface ground layered above the engineering bedrock, as shown in Figure 2.and Figure 3. The detailed contents of this paper is found elsewhere [2]. 1000 (100cm/s) (cm/s) V 100 (80cm/s) (24cm/s) velocity S 10 Response water supply, high pressure gus (L2) sewage water(L2) before the 1995 earthquake(L1) 1 0.1 1 10 Natural period of surface ground layer TG(s) Figure 1. Design response spectra of velocity on the engineering bedrock 376 Groud surface w av ele ng th U ( x') =U ･ h si Engineering n(2 π x y' bedrock '/L Vs≧300m/s ) x' Figure 2. The seismic ground displacement in seismic code of buried pipeline. D i re p ct r io o n p o a f ga w ti a on ve Ｌ Usx Us Usy θ cos ･ y Usy=Us θ x Us Buried pipeline X’ Usx=Us･sinθ Lx=L/cosθ Figure 3.The ground displacement distribution in the horizontal plane and relations of buried pipelines 377 CASE STUDIES IN THE NEAR FIELD OF DAMAGING ERTHQUAKES The damage to the water supply pipelines in the non-liquefiable ground from the 1995 Hyogoken-Nanbu earthquake and the 2004 Niigata-ken-chuetsu earthquake was compared with calculation results using the seismic design code of buried pipeline. Figure4 shows location of the water supply pipelines damage (only Ductile Cast Iron Pipe) from the 1995 Hyogoken-Nanbu earthquake[3], and the circles are the focus areas of this study. In these areas, the damage ratio of DCIP was high, and the damage mode was mainly the joint pull-out. Figure5 shows the calculation results of the joint displacement using the seismic design code and that allowed for joint displacement. Figure 6 shows the calculation results of the stress of the pipe material using the seismic design code and that allowed for the pipe material. The results showed that the joint pull-out occurred even if there was a margin of safety of about 2. In addition, it was the similar results in 2004 Niigata-ken Chuetsu Earthquake. It was estimated that the contradiction between the calculation results using the seismic design code revised after the 1995 earthquake and the damage to the water supply pipelines was in the evaluation of the ground displacement. Figure 4. Locations of the pipelines damage (only Ductile Cast Iron Pipe) in the non-liquefiable ground during the 1995 Hyogoken-Nanbu earthquake 378 5 allowable vale Takatori station Daikai station Sannomiya staion 4 Rokko-michi station Konan-yamate station 3 2 Joint displacement(cm) Joint 1 0 100 200 300 400 500 Pipeline diameter(mm) Figure5. Calculation results of joint displacement 300 2 250 allowable vale Takatori station Daikai station Sannomiya staion 200 Rokko-michi station Konan-yamate station 150 100 Stress of pipe (N/mm ) (N/mm pipe of Stress 50 0 100 200 300 400 500 Pipeline diameter (mm) Figure6. Calculation results of stress of pipe material 379 NEAR-FIELD EARTHQUAKE DISPLACEMENT OF THE NON-LIQUEFIABLE GROUND The seismic displacement of the non-liquefiable ground was computed using results from survey, strong motion observation and numerical simulation in the near field of the 1995 Hyogoken-Nanbu earthquake and the 2004 Niigata-ken-chuetsu earthquake. The 1995 Hogoken-Nanbu earthquake In order to estimate the seismic ground displacement of the 1995 Hyogoken-Nanbu earthquake, we performed the numerical simulation of the near fault area. The numerical simulation utilizing the boundary element method was done on 3 dimensions. The results of the seismic ground displacement calculations are shown in Figure 7 and Figure 8. The maximum ground displacement was more than 1 meter in the near-field. TABLE I shows a comparison of the seismic ground displacement at the study area in Kobe city. The dynamic displacement of the numerical simulation subtracted the permanent displacement from the maximum displacement. TABLE I. COMPARISON OF THE GROUND DISPLACEMENT ON ATTENTION AREA IN KOBE CITY Displacement Permanent Numerical simulation displacement of Location of seismic Maximum Dynamic Permanent design code survey displacement displacement displacement 1. Takaroti 10 25 63 49 14 station 2. Daikai 16 26 68 43 25 station 3. Sannomiya 8 10 44 32 12 Station 4. Rokkomichi 2 41 77 41 36 station 5. Kounan-yamate 6 46 114 72 42 station 380 Liquefaction area ( 100%) Liquefaction area (50%) The projection line of fault Figure7. Maximum ground displacement from numerical simulation Liquefaction area ( 100%) Liquefaction area (50%) The projection line of fault Figure8. Permanent ground displacement from numerical simulation 381 The 2004 Niigata-ken-chuetsu earthquake Figure 9 shows the permanent ground displacement obtained from the strong motion observation [4] and numerical simulation in the near field of the 2004 Niigata-ken-chuetsu earthquake. Because both of the permanent displacement yielded almost the same results, the accuracy of strong motion observations and numerical simulation was high. TABLE II shows comparison of the seismic ground displacement at K-net stations during the 2004 earthquake. The seismic displacement of the strong motion observation was computed using double integration of digitally recorded ground acceleration [5]. The dynamic displacement of the strong motion observation was more than 10 times compared with the displacement of the seismic design code. Strong-motion records Numerical simulation Figure9. Comparison of the permanent displacement obtained from strong-motion records, numerical simulation in the near field of the 2004 Niigata-ken Chuetu earthquake TABLE II. COMPARION OF THE GROUND DISPLACEMENT AT K-NET STATION Displacement Strong-motion Condition of surface ground of seismic observation (cm) Location Layer thickness Velocity of design code Dynamic Permanent (m) S-wave (m/s) (cm) displacement displacement OJIYA 3 100 0.2 46 10 NAGAOKA 3 100 0.2 14 5 KOIDE 4 118 0.3 11 26 TOKAMACHI 3 164 0.1 12 9 382 Characteristic of the ground displacement in near-field In near field, the seismic displacement of non-liquefiable ground based on actual survey became larger than the displacement using the seismic design code of the buried pipeline. It was found out that the dynamic displacement and the permanent displacement are large not only on the surface layer but also at the engineering bedrock, as shown in Figure10. On the other hand, in some cases, the ground displacement of the seismic design code is smaller than the actual ground displacement in near field, because it is not taken into account the ground displacement at the engineering bedrock Usmax U sp Usd Usr sur face Vs＜300m/s engineering bedrock Vs≧ 300m/s U bp Ubd Ubmax sismic bedrock Usmax:Maximum ground displacement on the surface Usp :Permanent ground displacement on the surface Usd :Dynamic ground displacement on the surface Ubmax:Maximum ground displacement on the engineering bedrock Ubp :Permanent ground displacement on the engineering bedrock U :Dynamic ground displacement on the engineering bedrock bd Figure10. The schematic explanation of the seismic ground displacement on the engineering bedrock and the ground surface. 383 CONCLUTIONS In this study, based on earthquake damage to water supply pipeline, we tried to find the reason followed by evaluation of the near-field earthquake displacement of the non-liquefiable ground and comparison with the displacement given by the seismic design code. As a result, the following findings were obtained: 1. The earthquake damage to the water supply pipeline occurred even if there was a margin of safety factor of about 2. 2. According to actual survey, strong motion observation and numerical simulation, the seismic displacement of non-liquefiable ground in the near field is larger than the displacement given by the seismic design code of the buried pipeline. 3. The contradiction in terms of the seismic ground displacement is attributed to the fact that the ground displacement at the engineering bedrock is not as negligibly small in the near field as assumed in the seismic design code . ACKNOWLEDGMENTS K-net strong motion data used in this study was provided by NIED. REFERENCES [1] Earthquake resistant design codes in Japan, JSCE, 2000 [2] Kimiyasu Ohtake, Tatsuo Ohmachi and Shusaku Inoue: The displacement of non-liquefiable ground in near field related to the damage of buried pipelines, Jour. JSCE, Vol. A63, No.1, pp. 93-107, 2007. (in Japanese) [3] The database of the water supply pipeline damages by 1995 Hyogoken-Nanbu Earthquake, Japan Water Works Association, 1997(in Japanese) [4] National Research Institute for Earth Science and Disaster Prevention:K-net,http://www.k-net.bosai.go.jp [5] Emmanuel H. Javelaud, Gota Kubo, Tatsuo Ohmachi and Shusaku Inoue: Coseismic ground displacement due to the 2004 Niigata-ken Chuetsu Earthquake, Japan, Proceeding of the 4th Annual Meeting of Japan Association for Earthquake Engineering, pp.312-313, 2005. 384 5th AWWARF/JWWA Water System Seismic Conference DISCUSSION SESSION AND CLOSING REMARKS 385 386 5th AwwaRF and JWWA Workshop Discussion Session Results August 16, 2007 The discussion session held on August 16, 2007 focused on three primary subjects: cost- benefit analysis, water storage and supply, and future directions. The discussion session provided useful and valuable information for advancing water system seismic practices. The main points derived from the discussion session are: • Cost-Benefit o Cost-benefit analysis is good to use as part of a water system seismic program to help show value in the improvements o It is important to use direct and indirect costs o Include initial and life cycle costs o Consider environmental factors and include the environmental costs o Need a means to properly asses life safety with due consideration that local governments are held to a high standard for protecting life o Avoided losses are benefits • Water Storage and Supply o Safeguarding water supply is an important issue for waterworks o Need a good definition on adequate water storage volume for earthquakes o There are several competing factors regarding water storage and supply Water storage vs. water quality Land and environmental impacts vs. area needed for storage Volume needed for firefighting vs. ability to supply the water in a damaged system o There are concerns and differing opinion on how rapid emergency drinking water can be distributed shortly after an earthquake o Long-term recovery should be a primary focus for planning because it is too difficult to develop high system reliability for large earthquakes o Need to define an expected level of service for water transmission from wholesale agencies o Citizens expect pressurized water to be available o Need direction for decision making on when to, or if one should, isolate post-earthquake storage instead of feeding it into a damaged system This is an issue of competing demands for post-earthquake firefighting water vs. longer-term drinking water • Future Directions o Agreement to continue workshop series every 1.5 to 2 years o The next workshop will be hosted by the Japan Water Works Association at a time and location to be determined, a suggestion was made to coordinate timing with the 8th International Symposium on Water Supply Technology o Developing water system seismic practices is a work in progress and continued communications is needed 387 o We hold the responsibility for our Cities and Countries to prepare water systems to resist earthquakes o We need to take the responsibility to disseminate the workshop information to other organizations, and staff within organizations o Need to identity ways to help smaller waterworks organizations implement seismic improvements o Suggested future topics include: Asset management Finances, manpower, and associated trade-offs for seismic improvements and earthquake response How to work with political leaders on seismic aspects Guidelines for seismic resistant measures (Japanese are working on) o Suggested improvements include: Three areas of focus: technical, policy, multi-hazard Include other participants such as fire fighters, emergency managers, primary water users, sewage companies/departments, etc. An overview of the discussions that transpired is presented below. As part of the water supply segment of the discussion, Craig Davis gave a PowerPoint presentation summarizing results of the pre-workshop survey. The presentation slides are included with this discussion summary. A summary of the survey results is also provided as part of these proceedings. Cost-Benefit Analysis: Adam Rose commented on the good use of cost-benefit analysis in seismic programs and specifically made note of Santa Clara Valley Water District. Crystal Yezman stated that cost-benefit analysis was identified as part of the Santa Clara Valley Water District scope of work and was performed by consultants. David Lee noted that FEMA requires a hazard mitigation plan to get Federal grant money. Most are not met the planning requirements. The Association of Bay Area Governments (ABAG) has prepared a hazard plans for cities. Twelve years ago the East Bay Municipal Utility District performed cost-benefit analysis and considered two categories, direct and indirect. For the East Bay Municipal Utility District a cost-benefit analysis using only the direct costs was not adequate justification to perform strengthening; it was cheaper to repair than to strengthen. However, when including indirect costs, such as impacts to the community, cost-benefit analysis showed a 6 to 1 payback. The total of direct and indirect costs was $1.2 billion. Use of indirect costs is worthwhile. The total mitigation cost is compared to the product of benefits times the probability of damage occurring. When mitigation cost is lower the mitigation is considered 388 worthwhile. This was found to only work out when the total of direct and indirect costs were considered. A rebuttal by Professor Shinozuka to this concept is that there may be an impression that mitigation for low probability earthquakes may not be worthwhile. Even when a discount rate of return is included, the mitigation may not seem worthwhile unless indirect costs. Therefore, indirect costs must be included in the benefit stream. The latest analysis procedures can factor additional events (who 50 year, 100 year, etc. recurrence). Also, the avoided losses are considered benefits. Life safety and the cost of human life are difficult for to quantify. Hidehiko Aihara suggested when planning, consider the initial cost in the cost-benefit evaluate. Yokohama also considers the durability and long term performance. This is not just the seismic issue, but a normal part of facilities planning. In some areas of Japan, the historical record shows they should expect great a earthquake in the next 30 years. In many places water systems are ran by local government. Local government must pay a higher price for life safety, they are held to a high standard for protecting life. The question is how to use cost-benefit analysis under such consideration. When considering the seismic upgrade strategy you must also take into account the vulnerabilities of other local facilities. When an earthquake hits it would not be a good situation if the only thing left is the water system. The implication is that seismic mitigation should be applied appropriately to call community aspects. Kazuhiko Mizuguchi stated that the City of Kobe local government is looking at buildings, life cycle costs, financial statements, and applying principles of asset management. Buildings are an asset. It was noted by others that some Cities in the United States are performing similar work. Also, in some cases environmental considerations are taken into account. Bill Cain pointed out the East Bay Municipal Utility District considered two types of earthquakes, a probable earthquake and a maximum earthquake. Previously, life cycle costs were not considered. However, now for evaluation of the aqueducts life cycle costs are being considered. David Pitcher gave a specific example of a dam for the Central Utah Water Conservancy District where the work needed to be completed was not found to be worthwhile on its own. However, when they included benefits to the environment, in this case fish, the project was justified and they even got $6 million in government funding. 389 Professor Shinozuka noted that there is a tremendous emphasis on energy and natural environment in the United States today. He now also emphasizes the built environment as part of the overall environment. Masaru Oneda commented that in Tokyo, citizens not only consider earthquake but also the environment. The citizens also approved the upgrading of a dam using their own funds, no support for local of national government, for the purpose of seismic improvement. Shingeru Hataya noted that cost/benefits are an economic analysis of facilities and life safety. Water systems in Japan are driven by either seismic upgrade or structure maintenance. Pipelines are embedded and hard to replace, they can be fixed when broken. Water treatment plants and other facilities can be upgraded as part of the Japanese level 2 seismic criteria. Water Storage and Supply Shingeru Hataya stated that the main issue is how to safeguard water supply and that should be our focus. Professor Hosoi commented that the United States is much larger than Japan; both have large and small cities. In Japan, if one city is struck by an earthquake then other cities move in to help. Professor Hosoi asked Craig Davis, with consideration of the workshop survey results he compiled, if the United States cities are more self contained and self sufficient. Craig Davis responded that he does not know if United States cities are more self sufficient than those in Japan. He cannot speak for other cities, but in Los Angeles the idea has historically been to attempt to store as much water as possible for use in times of emergency. Results of the survey show that Los Angeles has the largest volume per person of storage. However, Los Angeles is still concerned if they have enough storage for a large earthquake. What is inappropriate storage volume and how does the volume support recovery? A gentleman stated, in Japan if the in-reservoir water quality decreases over time, in twelve hours or so, you could run out of storage without time for restoration. An alternate Japanese opinion, a chlorine residual must remain and therefore water quality does not really decrease over time. In Japan 3 liters per person per day is a standard for earthquake response. After the second or third day only 3 liters per person creates a problem because they can’t bath or have water for other sanitary purposes. How much water per person is acceptable? David Lee stated on that drinking water does not seem to be a problem after an earthquake. This seemed to be the case even after the disastrous Kobe earthquake. This is because bottled water is available and many, including large corporations such as beer 390 and soda suppliers, provide aid with bottled water. The only problem is water for fire fighting. Bill Cain noted an additional issue: when water is stored for a long time and it is not turned over it goes bad. This goes against emergency preparedness goals. There is a balance to be considered. Mr. Kirkpatrick pointed out that when you look at maximizing storage a set of conflicting priorities and dilemmas manifest themselves related to water quality and supply. Raw/non-potable water has problems when developing environmental permits and with land space. Portable water is subject to water age degradation. Firefighting is another dilemma, if you assume a fair amount of pipelines are broken then you cannot distribute the water anyway and therefore how do you consider the fire fighting volume needed for storage. Long term recovery is the problem and where we have to focus on planning. Mankind will not step up, in general, to provide the financial backing for this high level of reliability. Ahmad Nisar raised a question about how much does each need? 250 liters per day? People are looking for pressurized water. Need to store a satisfactory level to meet citizen needs. Wholesale suppliers are not responsible for fire fighting water supplies. However, is there a mechanism for calculating a transmission level of service? In Japan some cities provide for emergency stop valves to retain and save water for emergency use. The rest of the storage will be used in the distribution for domestic or firefighting purposes and may leak out of broken pipes. The emergency water is isolated. The problem arises with having to make the decision to stop the water from flowing into the leaking distribution system and retain it for later emergency use. David Lee commented that maybe we cannot answer some of these questions because we do not separate drinking and fire fighting water. However, twenty liters per day is not much to us in the United States. Craig Davis commented on the differences in thoughts and strategies being discussed. If we look at the variations in different strategies perhaps both the Americans and Japanese can better learn from each other. The Japanese strategy is to isolate and save half of the storage for post earthquake emergency purposes and use the remainder through the distribution system. Is this a lesson learned from the Kobe earthquake? If you have a reasonable storage but loose most of it to leakage than it is useless. In Los Angeles a strategy is to keep large volumes of water for immediate use in the distribution system to help locate leaks for rapid repair and for fire flow. At this point, in the severely damaged areas water quality is not an issue until at least two or three days on after the earthquake and therefore non-potable emergency water supplies can be utilized. Professor Hosoi asked for the opinion of the Japanese delegates. 391 Kizahiko Minaguchi stated that in 1995 Kobe City lost many people because there was inadequate water supply for firefighting purposes. Also water could not be supplied as quickly as needed due to administrative issues. This led to installing automatic isolation valves on many tanks for emergency water storage. Also, Kobe Waterworks Bureau installed the large diameter transmission tunnel for additional storage. Kobe has also established water recycling programs which provides more access to firefighting water. The transmission tunnel provides 60,000 cubic meters of volume in an emergency. After an earthquake the transmission can be isolated and used as a large underground storage tank. Deep shafts provide means for pumping out the water and distributing it in containers to residents. People in the community practice this for emergency preparation. A question was asked by Fred von Hofe if there are adequate chemicals for treating stored water after an earthquake. Can this be a problem? Kobe responded that they have adequate chemical storage. Question for Dr. Siao-Syun Ke: when you published your results that Taipei was not ready for an earthquake what was the reaction? Dr. Ke responded by stating he did not tell this fact to the people broadly. There is enough water but not enough emergency equipment. Taipei Water Department can get additional supply from adjacent areas in a catastrophic event, but distribution would be a challenge. Future Directions and Closing There was unanimous agreement to continue having seismic workshops approximately every 1.5 to 2 years. The next workshop will be hosted by the Japan Water Works Association at a location to be determined. Considerations will be given for having the workshop in the Fall of 2009. Roy Martinez requested input on future workshop topics and improvements that can be made to the workshop. The number of new topics discussed during this workshop shows how this process is a work in progress and there is a need for continued communications to help improve water system seismic practices. (Bill Cain, East Bay Municipal Utility District) Future workshops can include asset management and other topics we can teach each other. (Kazuhiko Mizuguchi, Kobe Waterworks Bureau) For this workshop, the Japan Water Works Association requested papers on seismic practice and implementation; therefore all Japanese presentations were similar. Other topics can be considered in the future. It is difficult for the smaller waterworks 392 organizations to implement seismic upgrades. The Japan Water Works Association needs to inform the smaller organizations on how to make improvements and what others are doing around the world. As a result, it is important to continue this workshop series. (Kazutomo Nakamura, Japan Water Works Association) Seismic upgrades are important but need finances and manpower and we must consider the tradeoffs. We also need to deal with City Councils and other politicians who want to reduce the funding, cost of water, and manpower. We need suggestions on how to deal with this. This could be topic of future workshops. (Shigeru Hataya , Chiba Perfectural Waterworks Bureau) In response to Mr. Hataya’s statements, Bill Cain suggested to get more engineers on City Councils. 1997 guidelines for seismic resistant measures were prepared as a result of the 1995 Kobe earthquake. In March 2009 the guidelines will upgraded. This was suggested as a topic in the next workshop. Three tracts observed: Technical, policy, and multi-hazard. For multi-hazard there are other participants who are missing in the discussion, for example fire fighters, emergency managers, and other water users. We need to work closer with users to obtain a better understanding of their water supply needs. In doing this we will learn much more than just performing abstract engineering evaluations and discussions. (Comments from a manager of the East Bay Municipal Utility District) Need to spread information from this workshop to other organizations and to staff in our organizations to be more effective. Also need to include people from other fields to improve development. Need to include people from other fields to learn their opinions. After the 1995 Kobe earthquake learned we also need to work closer with sewer companies and would like to include this topic in the future. (Nobuhiro Hasegawa, JFE Engineering Corporation) A suggestion was made to hold the next workshop in June 2009 to allow United States participants to take advantage of the 8th International Symposium on Water Supply Technology to be hold in Kobe, Japan. 8th International Symposium on Water Supply Technology Kobe, Japan June 10th - 12th, 2009 Kobe International Convention Center Organized by the Steering Committee for 8th International Symposium on Water Supply Technology Supported by International Water Association 393 Continuing this workshop will improve our earthquake know-how. We have a responsibility to do this for our Cities and Countries. Roy Martinez, Craig Davis, Kazutomo Nakamura, and David Lee were recognized for their leadership and organization of this workshop. (Bill Cain, East Bay Municipal Utility District) Roy Martinez, on behalf of the American Water Works Association Research Foundation, thanked the Japan Water Works Association, Taiwan Water Works Association, all presenters and participants, Multidisciplinary Center for Earthquake Engineering Research, the Japanese interpreter, and the East Bay Municipal Utility District for a successful workshop. Professor Nagaoka, on behalf of Japanese participants and the Japan Water Works Association, thanked the American Water Works Association Research Foundation, Taiwan Water Works Association, East Bay Municipal Utility District, all participants, the Japanese interpreter, and the keynote speakers Professor O’Rourke and Professor Hosoi, for sharing knowledge and making a successful workshop. 394 55thth AWWARF/JWWAAWWARF/JWWA WaterWater SystemSystem SeismicSeismic WorkshopWorkshop Discussion Session August 16, 2007 1:30 – 5:00 PM Craig Davis August 16, 2007 1 395 PurposePurpose ¾¾ ShareShare informationinformation ¾¾ LearnLearn z FromFrom SSimilaritiesimilarities z FromFrom DifferencesDifferences ¾¾ ImproveImprove ¾¾ HelpHelp definedefine areasareas ofof neededneeded developmentsdevelopments andand futurefuture collaborationcollaboration Crag Davis August 16, 2007 2 396 SurveySurvey ¾ WaterWater StorageStorage andand SupplySupply ¾ PerformancePerformance CriteriaCriteria ¾ 2020 Responses!Responses! ThankThank You!!You!! ¾ InitialInitial resultsresults summarizedsummarized inin TablesTables (handed(handed out)out) ¾ ResultsResults usefuluseful forfor understandingunderstanding strategiesstrategies othersothers areare implementingimplementing ¾ PlanPlan toto improveimprove andand sendsend finalfinal afterafter workshopworkshop Crag Davis August 16, 2007 3 397 SurveySurvey ResultsResults SummarySummary ¾ Wide Range of Organizations and Conditions ¾ Water Wholesale Suppliers & Distributors ¾ Storage: 18,760,235 m3 LADWP 43,000 m3 Tottori City ¾ Population: 12,246,523 Tokyo 150,000 Tottori City ¾ Service Area: 1,834 km2 MLGW 211 km2 Osaka 98 km2 Tottori City Crag Davis August 16, 2007 4 398 SurveySurvey ResultsResults SummarySummary SupplySupply ¾ 77 ofof 1199 statedstated theythey havehave enoughenough postpost-- earthquakeearthquake waterwater supplysupply ¾ 88 dodo notnot ¾ 33 dondon’’tt knowknow ¾ AllAll butbut 44 indicatedindicated theythey havehave emergencyemergency interinter--connectionsconnections ¾ AllAll butbut 55 describeddescribed plansplans forfor distributingdistributing emergencyemergency drinkingdrinking water.water. Crag Davis August 16, 2007 5 399 SurveySurvey ResultsResults SummarySummary SupplySupply ¾¾ FireFire FollowingFollowing EarthquakeEarthquake z 11 U.S.U.S. organizationorganization (SFPUC)(SFPUC) identifiedidentified specialspecial firefire fightingfighting waterwater supplysupply z 11 JapaneseJapanese organizationorganization ((NagoyaNagoya)) identifiedidentified specialspecial firefire fightingfighting waterwater supplysupply z SomeSome JapaneseJapanese FireFire DepartmentsDepartments installinstall cisternscisterns ¾¾ MostMost relyrely onon emergencyemergency supplysupply toto assistassist inin fightingfighting fifirreses (same(same supplysupply usedused forfor peoplepeople’’ss emergencyemergency drinkingdrinking waterwater).). Crag Davis August 16, 2007 6 400 SurveySurvey ResultsResults SummarySummary PerformancePerformance CriteriaCriteria ¾¾ AllAll butbut 22 havehave specifiedspecified performanceperformance criteriacriteria z JapaneseJapanese criteriacriteria similarsimilar forfor allall organizationsorganizations ¾¾ MostMost havehave anan estimateestimate ofof restorationrestoration timestimes ¾¾ MutualMutual AidAid // AssistanceAssistance z AllAll JapaneseJapanese havehave agreementsagreements z OnlyOnly 44 U.S.U.S. respondentsrespondents havehave agreementsagreements Crag Davis August 16, 2007 7 401 PreliminaryPreliminary EvaluationEvaluation ¾ StorageStorage volumevolume perper capitacapita z Post-earthquake usable storage 3 z Range: 0.07 m /person (Kanagawa) 0.03 m3/person (Santa Clara) 0.26 m3/person (Fukuoka) 2.2 m3/person (EBMUD) 4.6 m3/person (LADWP) ¾ WholesaleWholesale supplierssuppliers typicallytypically havehave lowerlower volumevolume perper personperson ¾ U.S.U.S. typicallytypically greatergreater thanthan JapanJapan ¾ JapanJapan distributorsdistributors rangerange fromfrom 0.260.26 toto 0.370.37 mm3/person/person Crag Davis August 16, 2007 8 402 QuestionsQuestions ¾ WhatWhat isis anan adequateadequate ppostost--eearthquakearthquake waterwater supplysupply andand howhow dodo wewe determinedetermine thatthat volume?volume? ¾ WhatWhat isis aa goodgood assumptionassumption onon postpost--earthquakeearthquake consumptionconsumption fromfrom distributiondistribution system?system? ¾ AreAre wewe accountingaccounting forfor allall parametersparameters whenwhen estimatingestimating waterwater supplysupply needed?needed? ¾ WhatWhat isis rolerole ofof wholesalewholesale suppliers?suppliers? ¾ HowHow shouldshould firefire fightingfighting bebe consideredconsidered inin determiningdetermining postpost--earthquakeearthquake waterwater supplies?supplies? Crag Davis August 16, 2007 9 403 QuestionsQuestions ¾ WhatWhat isis anan acceptableacceptable minimumminimum levellevel systemsystem functionality?functionality? ¾ AreAre wewe implementingimplementing thethe appropriateappropriate mitigationsmitigations toto actuallyactually reachreach ourour performanceperformance goals?goals? ¾ HasHas everyoneeveryone adequatelyadequately consideredconsidered regionalregional earthquakeearthquake disasters?disasters? ¾ IsIs thethe performanceperformance criteriacriteria describeddescribed toto thethe communitycommunity (residents(residents andand businesses)businesses) ssoo theythey cancan prepareprepare accordingly?accordingly? Crag Davis August 16, 2007 10 404 FutureFuture CooperationCooperation ¾¾ YoungYoung fieldfield –– muchmuch cancan stillstill bebe improvedimproved inin waterwater ssystemystem seismicseismic programsprograms ¾¾ ContinueContinue workshopworkshop seriesseries ¾¾ AnyAny interest/abilityinterest/ability forfor otherother typestypes ofof collaborationcollaboration (committees,(committees, workwork groups)?groups)? ¾¾ JJWWWWAA implementingimplementing seismicseismic planningplanning programprogram forfor allall waterworks.waterworks. z IsIs thisthis aa goodgood areaarea forfor collaboration?collaboration? ¾¾ MultiMulti--hazardhazard considerationsconsiderations Crag Davis August 16, 2007 11 405 406 5th AwwaRF-JWWA Water System Seismic Workshop Information Survey A pre-workshop survey, presented at the end of this section, was sent to all workshop participants. The survey requested information relating to: 1. Post-earthquake water storage and supply available for use after an earthquake, 2. Water System post-earthquake performance criteria, and 3. Water system information related to earthquake performance. The survey request presented herein is slightly modified from that originally sent out before the workshop to reflect follow-up questions sent to respondents. Responses were received from 19 different waterworks organizations, 8 from the United States and 11 from Japan. In addition, the Japan Water Works Association and the Japan Water Research Center responded with some general information. The survey results are presented using English units in Tables 1E, 2E, and 3E and metric units in Tables 1M, 2M, and 3M. Tables 1E and 1M are identical except for the units used; similarly for Tables 2E and 2M, and Tables 3E and 3M. As a result, this description will only refer to Tables 1, 2, and 3, leaving the reader to refer to the English or metric versions. The tables reflect information provided as part of the original survey response and follow up requests for information. Draft tables were handed out at the workshop to all participants for review and comment and requests for suggested modifications were sent out immediately following the workshop. The tables reflect all suggested modifications from the participants. A blank in a table cell means information is not applicable or was not provided. The survey results are useful for: ¾ Comparing different water system aspects, ¾ Defining a current state of practice in water system seismic preparedness, ¾ Understanding earthquake practices and strategies different waterworks organizations are implementing, and ¾ Obtaining ideas on what waterworks organizations are doing to prepare for earthquakes (especially in Table 3). Table 1 presents system general information identifying the waterworks organization, the person responding to the survey, if the organization is a distributor or wholesale water supplier, service region and area, and other statistics related to the individual systems. Fifteen distributors (6 from the United States and 9 from Japan) and 5 wholesale agencies (3 from the Unites States and 2 from Japan) responded to the survey. The organizations were identified as distributors or wholesalers in Table 1 based on their primary function. The San Francisco Public Utilities Commission (SFPUC) is unique in that it is identified in Table 1 as a distributor to the City of San Francisco and as a wholesaler to 28 San Francisco Bay Area agencies due to significant dual functions that organization performs. A more detailed justification for distinguishing between the different SFPUC functions is presented at the bottom of Table 1. Tables 2 and 3 also present SFPUC information relating to the distribution or wholesale functions. Table 2 presents earthquake water supply information and identifies each organization’s understanding if they have an adequate water supply, the basis for and how they evaluated supply adequacy, and any special provisions for: fire fighting water supply, additional emergency water sources, and emergency drinking water distribution. Table 3 Survey Summary-1 407 5th AwwaRF-JWWA Water System Seismic Workshop focuses primarily on performance criteria and emergency response information identifying the general ground failure hazard, a listing of any specified performance criteria, estimates of restoration time and bases for the estimate, number of employees expected to be available for post-earthquake restoration, in any mutual aid/assistance agreements are in place, alternate forms for assistance, and any stockpiled materials and equipment specifically for earthquake purposes. The table headings are intended to summarize the information presented in each column. Refer to the actual survey questions at the end of this section to see obtain a better understanding for the basis of each response. Additional useful information that could be added to Tables 1 to 3 is flow rate data (peak, annual average, maximum daily, etc.) An overview of the survey results is given in the PowerPoint slides provided in these proceedings and presented as part of the Discussion Session. The overview will not be repeated here. Data in Tables 1 to 3 are useful for performing preliminary evaluations to compare different water system capabilities and developing metrics for earthquake preparedness. Figure 1 presents an example of a simple evaluation of usable storage volume per capita. The horizontal axis in Figure 1 identifies each waterworks organization using their initials in the order presented in Table 1. As seen in Figure 1 the surveyed organizations provide a wide range of storage per capita. Waterworks organizations in the United States generally have more storage per person than Japan. Wholesale agencies, except for the SFPUC, generally have less storage/person than distributors as a result of providing bulk supplies to several large constituent agencies. The ranges are as follows: Distribution: low 0.26 m3/person (69 gal/person) Fukuoka City WB high 4.63 m3/person (1,223 gal/person) Los Angeles DWP Wholesale: low 0.03 m3/person (8 gal/person) Santa Clara Valley WD high 2.12 m3/person (560 gal/person) San Francisco PUC The Japanese distribution waterworks storage per person fall within a tight range of 0.26 to 0.37 m3/person (69 to 98 gal/person). 5 4.63 4 /person) 3 3 2.27 2.12 2.04 2 1.05 1.05 Storage per Capita (m 1 0.55 0.37 0.27 0.26 0.33 0.27 0.29 0.27 0.29 0.27 0.16 0.03 0.11 0.07 0 D B B A B WD C C-d C-w WD W WB TC C W LGW U U V PW WS K MWB YW A CCWD M C FC HWSA K NWSB OMWB T CU EBMUD LADWP FP FP SC HRWSA S S Organization Figure 1. Storage per capita. Survey Summary-2 408 5th AwwaRF-JWWA Water System Seismic Workshop The simplified evaluation shown in Figure 1 provides insight into the relative abilities to provide post-earthquake water, but is not adequate to make any determination regarding any of the water systems’ expected seismic performance. Many more parameters must be considered and evaluated to make that kind of determination such as seismic ground motion level and intensities, pipeline and other component fragilities, repair capabilities, system isolation and redundancy capabilities, etc. A detailed evaluation of the data presented in Tables 1 to 3 is beyond the intent of this document. The data is being presented for comparative purposes, to promote thought and discussion, and allow others to further evaluate the data as appropriate with the intent of fostering advances in water system seismic practices. However, the data does allow initial observations to be made as follows: • Tables 1 to 3 show a wide range of results differing for nearly every organization, • The determination of an adequate post-earthquake water supply is deferent for different organizations, and in some cases is tied to the defined performance goals, • The minimum level of functionality varies by organization, • Some organizations have not determined an acceptable minimum level of service, • Few, if any, directly consider fire fighting water in their estimates for needed post- earthquake water supplies, • Stored water should be adequately distributed around the system; it may not be enough to simply have enough water at a few locations, • Japan has defined minimum storage and performance criteria, whereas the United States does not, • There are a wide range of practices and strategies being implemented, and all organizations can learn from the different practices and strategies. Review of the data, along with discussions and presentations during the workshop, identifies areas needing further development: • How to estimate post-earthquake consumption from the distribution system, • The role of wholesale suppliers, • How to consider fire fighting water in determining post-earthquake water supplies, • Better tools to account for all parameters when estimating the water supply needed for earthquakes, • Methods and procedures for identifying acceptable minimum level system functionality, • Considerations of regional earthquake effects and reliance on local/neighboring agencies for post-earthquake recovery support, • Communicating defined performance criteria and level of services to communities (residents and businesses) to allow their preparation accordingly, • How to implement appropriate mitigations to meet the performance goals. In summary, the survey results and discussions that transpired in response to the survey information indicates that may organizations are implementing very good practices and strategies for system-wide improvements. At the same time, the information reveals that the general field of water system seismic engineering (with an emphasis on “system” referring to a systems approach) is still young and much can still be learned and improved in all water system seismic programs. Survey Summary-3 409 410 Table 1E. System General Information (English units). Organization Service Population Service Pipe Length Pipe Total Storage Number of Storage Size (survey Connections (miles) Diameter Capacity Tanks and Range (gallons) responder) Range (gallons) Reservoirs Type Region Area See Table 1a See Table 1a (inches) (mi2) United States Alameda County Distributor Cities of 103 324,800 78,150 total 871 total 2 – 48 90,000,000 13 total 500.000 to Water District Fremont, 69,000 sf 1 ci 7 tanks 21,000,000 (Threse Newark, and 2,020 mf 99 s 6 in-ground Wooding) Union City, 3,480 c/i/g 136 p reservoirs California 1,830 LI 629 ac 1,820 fh 6 O Central Utah Wholesaler 10 counties 1,200,000 Wholesale to 25 80 total 18 – 120 50,000,000 6 tanks 760,000 to Water service 50 s 8 raw water 20,000,000 Conservancy providers 1.2 P301S reservoirs District (David 4.7 RC Pitcher) 24 tunnels Contra Costa Distributor Central and 214 270,000 88,000 total 790 total 2 – 96 75,000,000 40 250,000 to Water District Eastern 53,000 sf 13 ci 7,000,000 (Steve Welch) Contra 30,500 mf 26 di Costa 4,000 c/i/g 133 s County, 500 A/I (raw) 185 p California 500 R 430 ac East Bay Distributor Portions of 325 1,300,000 403,402 total 4,136 total 2 - 108 780,000,000 170 3,000 to Municipal Alameda 320,478 sf 1,361 ci treated water 154,000,000 Utility District and Contra 29,277 mf 2 di (Bill Cain) Costa 4,697 A/I 1235 s Counties, 48,950 O 363 p California 1,146 ac 10 PCCP 14 RCCP 0.7 copper 3 wrought iron 0.6 O Los Angeles Distributor City of Los 465 4,050,000 712,351 total 7,230 total 2 – 144 4,956,469,000 108 potable 1,700 to Department of Angeles, 614,253 sf+mf 4,740 ci potable water 3,313,718,000 Water and Power California 83,744 c/i/g 708 di 4 raw water (Craig Davis) 631 O 1,044 s 7,945,878,000 (emergency 0.6 p raw (stored in storage only) 610 ac the distribution 83 concrete system area) 28 copper 16 O Table 1E – page 1 411 Organization Service Population Service Pipe Length Pipe Total Storage Number of Storage Size (survey Connections (miles) Diameter Capacity Tanks and Range (gallons) responder) Range (gallons) Reservoirs Type Region Area See Table 1a See Table 1a (inches) (mi2) Memphis Light Distributor City of 708 850,000 253,759 total 3,672 total 2 – 36 123,500,000 34 100,000 to Gas and Water Memphis 228,656 res 3,659 ci+di 15,000,000 (Fred von Hofe) unincorpor- 19,924 c/i/g 0.8 s ated areas of 5,179 O 4 p Shelby Co., Cities of Arlington & Lakeland, Tennessee San Francisco Distributor* City of San 47 770,000 Approximately 1,250 total 0.75 – 78 415,000,000 21 75,000 to Public Utilities Francisco, 250,000 total Consisting 89,400,000 Commission* California mainly of ci, (Luke Cheng) some ci being replaced with di San Francisco Wholesaler* 28 agencies 2,477 1,700,000 150 turnouts to 1,193 total 28 – 96 953,000,000 24 1,000,000 to Public Utilities in San residential, Bay Area Water Consisting 661,600,000 Commission* Francisco commercial, Supply and mainly of s, (Luke Cheng) Bay area, and industrial Conservation RCCP, PCCP California users District agencies Santa Clara Wholesaler Santa Clara 1,300 1,700,000 45 total 150 total 20 – 120 55,395,060,000 10 raw 130,000,000 to Valley Water County, 18 A/I 37.5 s Mostly raw 1 treated 29,000,000,000 District (Erin California 27 wholesale 108 PCCP water not usable (raw) Baker) retailer turnouts 4.5 RCCP for earthquake 15,000,000 response. (treated) Japan Chiba Prefecture Distributor 11 cities and 217 2,830,000 unknown 5,244 total 2 – 71 203,434,610 792,602 to Waterworks 2 towns 4981 di 15,852,048 Bureau (Shigeru (Chiba, 105 s Hataya) Funabashi, 11 ac Matsudo, 147 HIPV Ichikawa, -replaced 1,429 Ichihara, mi ac Narashino, Urayasu, Shiroi, Inzai, Narita, Imba, Motono) Table 1E – page 2 412 Organization Service Population Service Pipe Length Pipe Total Storage Number of Storage Size (survey Connections (miles) Diameter Capacity Tanks and Range (gallons) responder) Range (gallons) Reservoirs Type Region Area See Table 1a See Table 1a (inches) (mi2) Fukuoka City Distributor Fukuoka 90 1,402,200 736,380 total 2,348 total 1.6 – 71 96,723,910 45 (17 sites) 15,852 to Waterworks City unknown sf 90 ci 5,918,098 Bureau (Kuniaki unknown mf 2,226 di Nakamura) 64,062 c/i/g 24 s 98 A/I (other 1.8 p system) 1,592 R Hachinohe Distributor 1 city 308 336,276 131,642 total 1,130 total 3 – 59 29,221,136 47 14,795 to Regional Water (Hachinohe) 122,212 sf + mf 22 ci 2,642,008 Supply 6 towns 9,430 c/i/g 926 di Authority (Oirase, 6 s (Norbou Gonohe, 129 p Murakami) Rokunohe, 48 ac Hashikami, Nanbu, Sannohe) Hanshin Water Wholesaler Kobe, 185 2,500,000 21 supply points 78 total 12 – 94 69,431,968 15 343,461 to Supply Ashiya, Kobe (6), 7 ci 21,136,063 Authority (Shinji Nishinomiya Ashiya (4), 33 di Nakayasu) and Nishinomiya (8) 24 s Amagasaki Amagasaki (3) 0.6 ac Cities 14 tunnel Kanagawa Water Wholesaler Kanagawa 575 8,007,450 40 supply points 124 total 31 – 110 141,770,145 17 1,321,004 to Supply Prefectural, total for 4 37 di 15,852,048 Authority (Ken- Yokohama constituent waterworks 67 s ichi Koike) City, waterworks 21 di + s Kawasaki has 50% City, and dependence Yokosuka on KWSA City water Kobe Distributor Kobe City 213 1,523,521 744,592 total 3,049 total 2 – 94 148,776,750 251 (123 7,926 to Waterworks 700,910 sf+mf+ 874 ci sites) 10,303,831 Bureau school+hospital 1,922 di (Kizuhiko 444 ABK 143 s Mizuguchi) 74 pbh 110 p 43,164 o/f Nagoya Distributor Nagoya City 137 2,316,000 793,208 total 5,006 total 0.6 – 79 167,658,917 43 7,662 to Waterworks and 501,539 sf 142 ci 13,210,039 Sewerage 67,487 mf 3,175 di Bureau (Yukio 224,182 c/i/g 23 s Mabuchi) 1,663 p 2.4 O Table 1E – page 3 413 Organization Service Population Service Pipe Length Pipe Total Storage Number of Storage Size (survey Connections (miles) Diameter Capacity Tanks and Range (gallons) responder) Range (gallons) Reservoirs Type Region Area See Table 1a See Table 1a (inches) (mi2) Osaka Municipal Distributor Osaka City 81 2,600,000 925,000 total 3,108 total 3 – 79 202,298,547 10 132,100 to Waterworks 411,000 sf 516 ci 26,657,860 Bureau (Hiroaki 369,000 mf 2,548 di Miyazaki) 144,000 c/i/g+R 44 s Tokyo Distributor Tokyo City 470 12,246,523 6,550,765 total 15,700 total 2 – 106 870,117,041 176 793 to Metropolitan (2005 FY) 6,328,931 sf 230 ci 75,772,787 Waterworks 220,911 mf 15,232 di Bureau (Masaru 923 pbh 221 s Oneda) 217 O 16 p 0.6 ac Tottori City Distributor Tottori City 38 150,000 49,000 total 696 total 0.8 – 47 11,360,634 31 52,840 to (Prof. Yosihiko 17 ci 2,642,007 Hosoi) 465 di 15 s 199 p Yokahama Distributor Yokahama 168 3,623,795 1,696,549 total 5,589 total 3 – 79 255,667,107 39 (23 sites) 1,532,364 to Waterworks City 1,696,549 sf+mf 3,978 ci + di 35,931,307 Bureau (Ken 68,838 c/i/g 1,101 s Yokoyama) 124 pbh 508 p 2.5 concrete *San Francisco Public Utilities Commission (SFPUC) is responsible for water distribution to the City of San Francisco and wholesale supply to suburban agencies in portions of Alameda, Santa Clara, and San Mateo Counties represented by the Bay Area Water Supply and Conservation District (www.bawsca.org). For purposes of tabulation, the distribution and wholesale portions of SFPUC are presented separately for better comparison. Although the SFPUC system cannot be completely separated into two independent systems, for tabulation purposes information for SFPUC wholesale for the most part does not account the City of San Francisco distribution, and vice versa. The SFPUC is tabulated in two parts because the distribution component of SFPUC is similar to the Los Angeles Department of Water and Power, East Bay Municipal Utility District, and others who have their own aqueduct supplies but are not considered wholesalers to themselves and the wholesale component of SFPUC is similar to Santa Clara Valley Water District, Hanshin Water Supply Authority, and others who do not distribute water directly to customers. Table 1a. Service Connection and Pipe Type abbreviations. Service Connection Pipe Type sf = single family dwellings ci = cast iron mf = multi-family dwellings di = ductile iron res = residential s = steel c/i/g = commercial/industrial/government p = plastic (e.g. PVC) A/I = Agriculture/Irrigation O = Other R = Recreational ac = asbestos cement O = Other PCCP = Prestressed Concrete Cylinder Pipe LI = Landscape Irrigation RCCP = Reinforced Concrete Cylinder Pipe fh = firelines and hydrant RC = Reinforced Concrete pbh = public bath houses P301S = Prestressed 301 Steel ABK = Apartments sharing Bath and Kitchen o/f = offices/factories Table 1E – page 4 414 Table 2E. Earthquake Water Supply Information (English units). Organization Adequate Post- Earthquake Supply? Post-Earthquake Fire Additional Emergency Water Emergency Drinking Water Fighting Provisions Evaluation Basis United States Alameda County Don’t know No special provisions at No special provisions at this time No special provisions at this time Water District this time Central Utah Don’t know Water Conservancy District Contra Costa Yes (for Fragility analysis performed – No special provisions 10 emergency interconnections [with Contra Costa Water District is responsible for Water District emergency results used to implement East Bay Municipal Utility District (2 public drinking water response. No other plans demands seismic improvement program treated, 1 raw), Cities of Martinez (2), in place in the event Contra Costa Water not normal focused on rapid recovery. Pittsburg (2), Antioch, Brentwood, and District’s system is insufficient. demand) Diablo Water District] totaling 103 mgd treated and 100 mgd untreated. East Bay Yes East Bay Municipal Utility Terminal storage Interconnections with the San Francisco Will follow regional office of Emergency Municipal District performed systematic reservoirs Public Utilities Commission and Contra Services directions Utility District evaluation of distribution system 53,765,795 gal loaded by Costa Water District capable of using Monte Carlo simulation of helicopter for fighting supplying 30-50 mgd. 4 scenario earthquakes ranging urban-wild land interface from an operating earthquake of fires. M6.0 on Hayward fault to maximum credible events of M7.0 Hayward fault, M6.75 Calaveras fault, and M6.5 Concord fault. The damage that occurred in the simulations was used to guide development of a 10-year Seismic Improvement Program (recently completed) in which facilities and pipelines contributing to overall post- seismic system performance were fixed. Table 2E – page 1 415 Organization Adequate Post- Earthquake Supply? Post-Earthquake Fire Additional Emergency Water Emergency Drinking Water Fighting Provisions Evaluation Basis Los Angeles Yes No specific evaluation has been -No added fire storage -The Los Angeles Department of Water - Los Angeles Department of Water and Department of performed. The Los Angeles volume. and Power can utilize more than 25 Power has a plan to provide drinking water Water and Power Department of Water and Power -Inter-system connections Metropolitan Water District of Southern emergency water distribution stations. A P has historically maintained a allow fire engine pumping California (wholesale supplier) station will consist of one or more 350-gallon large volume of water supply in units to pump from a connections to receive additional potable water storage bladders and PVC pipe the distribution network that lower pressure to higher supplies. manifold with dispensing spigots, set up on a aided the system recovery pressure zone through -The Los Angeles Department of Water pair of extra strong aluminum folding tables. during the 1971 San Fernando adjacent fire hydrants. and Power has a few small connections 50 bladder-manifold kits are stored in a sealed and 1994 Northridge -Helistops at reservoir and other municipal water agencies (Beverly 55-gallon steel drum to keep it clean and ready Earthquakes. The assumption is mountainous regions (e.g., Hills, Long Beach, Inglewood El for use and stand at 6 district yards around the that this supply will be adequate Elysian Park) Segundo, Las Virgenes, Los Angeles City. in future earthquakes. -Fire fighters take County Waterworks District No. 29), -When deployed, the stations will be advantage of swimming primarily to provide water to them, repeatedly filled by potable water tender pools as added supply however it may be possible for the Los tankers. Los Angeles Department of Water (this is a usable supply, Angeles Department of Water and Power and Power plans to purchase, store and but not specifically to receive some water from these maintain in a ready state two stainless steel identified as an alternate agencies in an emergency. tanker trailers of 3,700-gallons capacity each, supplemental supply for as a means of immediate first response. fire suppression). Additional tankers will be employed as needed through spot rental and mutual aid. Memphis Light Yes Currently having this checked Maintain 8 - 30 mgd Have interconnections with a number of Unlike most systems Memphis Light Gas and Gas and Water by consultant plants at different small systems that could be used on Water has 8 major plants and anticipates locations, if one fails emergency basis. several plants will survive a major earthquake. others can pick up load if Water from operating plants available for fire distribution system fighting, sanitation, and drinking. functions. San Francisco Yes Levels of Service (LOS) Goals 400 million gallons Interconnections with East Bay Approximately 70 potable water hydrants Public Utilities following completion of the domestic supply; an Municipal Utility District and Santa throughout the City of San Francisco are Commission Water System Improvement additional 2 billion gallons Clara Water District allow water sharing marked with a blue water drop, and serve as (S.F. City Program (WSIP) in 2014: non-potable fire capacity up to 70 mgd. emergency water distribution sites following distribution, suppression reserves in an earthquake or other disaster. They will be see * bottom of Deliver minimum system cisterns, local lakes, manned by San Francisco Public Utilities Table 1) demand (winter month demand) untreated reservoirs, etc. Commission crews and neighborhood within 24 hours after a major emergency response teams following a earthquake. Minimum winter The San Francisco Fire disaster. Additionally, the San Francisco Zoo month demand is estimated at Department maintains an Well serves as an emergency potable water 215 mgd in 2030. auxiliary water supply supply. The Zoo Well project includes a truck system independent of the fill station, disinfection facilities, upgrade of Deliver average demand under water distribution system the existing power system for the well, and an the condition of one unplanned and dedicated only to fire emergency generator outage concurrent with one fighting. planned outage of major facilities. Average demand in 2030 is estimated at 300 mgd. Table 2E – page 2 416 Organization Adequate Post- Earthquake Supply? Post-Earthquake Fire Additional Emergency Water Emergency Drinking Water Fighting Provisions Evaluation Basis San Francisco Yes LOS Goals following WSIP Local lakes and reservoirs; Interconnections with East Bay Varies by wholesale customer/jurisdiction. Public Utilities contingency plans and Municipal Utility District and Santa Some can use groundwater. Commission At least 70 percent of the emergency storage vary Clara Valley Water District allow water (wholesale, turnouts within each region by wholesale customer/ sharing capacity up to 70 mgd. see * bottom of should receive flow to achieve jurisdiction. Table 1) minimum month demand for the Other provisions vary by wholesale region. Estimated 2030 customer/jurisdiction. minimum month demands for the three regions noted above are 96 mgd, 37 mgd, and 82 mgd respectively. Restore facilities to meet average demand within 30 days after a major earthquake . Santa Clara No Modeled seismic hazard events No special provisions -Interconnection with San Francisco No special provisions Valley Water to determine water supply Public Utilities Commission District infrastructure reliability. -Planned future well fields for emergency Although the Santa Clara Valley supplies Water District (District) has enough raw water storage, the Infrastructure Reliability Project found that the District would not likely be able to treat and deliver the water following a seismic event due to treatment plant damage and numerous pipe breaks and leaks. The District has available groundwater and is implementing a project that will provide wells for emergency water supply. Table 2E – page 3 417 Organization Adequate Post- Earthquake Supply? Post-Earthquake Fire Additional Emergency Water Emergency Drinking Water Fighting Provisions Evaluation Basis Japan Chiba Prefecture Yes Installed emergency stop valves No special provisions Supply provided to Chiba Prefecture -10 water supply trucks with 528-1,057 gal. Waterworks in the distribution reservoirs up Waterworks Bureau by 2 wholesale water -69 water tanks with 264 gallons Bureau to 114 million gallon storage supply authorities totaling about 61 mgd. -50,000 aluminum canned water capacity. The remaining 90 If the two water supply authorities remain -1,775 water tanks with 5.3 gallons million gallons can flow for operable after earthquake, they can -60,000 water supply bags with 1.6 to 2.6 gal. domestic and fire fighting use. supply 8 to 13 mgd more than usual. -Emergency faucets and fire hydrants in 5 purification plants and 14 treated pump stations used to distribute water, once water restored to those plants and stations. -Emergency water brought to refuge places and medical care institutions with the aid of Water Piping Construction Cooperative Society, before other municipal water supply entities come to aid. Support agreement maintained with Society for emergency water. Fukuoka City Yes The essential water volume in No special provisions, but 2 connections with the water wholesale Anti-earthquake pipe lines used for important Waterworks the first stage on the emergency system designed with agency, one connection with neighboring distribution lines connecting trunk line to Bureau is estimated 0.8 gallons per seismic resistant ductile city in order to assist each other in evacuation sites. Also have two water carrier person. It means the essential iron pipe so many emergencies. vehicles to supply drinkable water to water total daily volume sum up to hydrants on distribution suspended areas. 740,000 gallons, which is far pipe can be available for smaller than existing storage fire fighting. capacity. Hachinohe No Because maintenance of the No special provisions No special provisions Emergency water obtained from fire-plug and Regional Water block distribution system is seismic storage tank. Drinking water Supply insufficient, mutual flexibility is prioritized and transported to medical Authority impossible. Therefore, when the institutions and to the elementary schools used earthquake damage happens, for refuge. Standard is 0.8 gallons/day/person. enough water cannot be As emergency repair advances the amount of supplied to the customer. the water offered from distribution network is increased. Hanshin Water No Have not performed an No special provisions Have 4 emergency water supply facilities No plan, in the business of wholesale water Supply evaluation because this supply, but will support customers. Authority organization is in the business of wholesale supply to distributing organizations Kanagawa Water No See Note 1. No special provisions. Have interconnection raw water main Kanagawa Water Supply Authority is a bulk Supply Cannot prepare counter- between two different water resources. water supplier, but can supply drinking water Authority measures for earthquake to 4 waterworks (constituent bodies) at main scenarios because fault reservoirs. Kanagawa Water Supply Authority positions cannot be clearly trains for emergency supply with constituent identified. bodies every year. Table 2E – page 4 418 Organization Adequate Post- Earthquake Supply? Post-Earthquake Fire Additional Emergency Water Emergency Drinking Water Fighting Provisions Evaluation Basis Kobe No, but are Planning emergency storage of -The emergency water Emergency connections with neighboring An emergency system provides storage every Waterworks in progress 0.8 gallons/person/day. Will storage system developed water suppliers; 7 pipes with 5 cities. Up 1.2 mile radius for efficient conveyance of Bureau of creating soon have enough storage up to for drinking water supply to 2 million gallons of water can be drinking water supply trucks. 47 sites cover enough 7-days. would also be used for fire delivered in emergency situation. the whole city. 37 systems are completed at emergency fighting. present, and emergency water is secured about storage Supply for full recovery -Fire Department built and 14.3 million gal. See also Note 2 for Table 3. dependent upon other sources. maintain 252 earthquake Kobe only has 25% of it own resistant water supply Store several types of carrying containers for water sources. cisterns for emergency fire emergency use in seven branch offices. fighting. 6.7 million -11,240 back pack water bags (1.6 gallons) gallons total volume. -10,249 water tank container (0.5 -4.8 gallons) Nagoya No Nagoya Waterworks has Nagoya Fire Fighting 11 Emergency connections with 7 200 emergency water supply facilities located Waterworks and sufficient total water supply Bureau constructed 568 neighboring waterworks for total of 18 so all residents can reach on foot. Sewerage after upgrading water reservoirs. earthquake resistance fire mgd. 208 underground hydrants installed in Bureau The total purified water storage prevention water tanks in distribution pipes leading to elementary capacity is 168 million gallons, 2006. schools that are used as evacuation sites. indicating that water supply of 12 hours or more with respect to a design daily maximum water supply volume of 329 million gallons is secured. However, there is still a problem of resolving the regionally uneven distribution that exists in the amount of water stored. Osaka Municipal No Total storage capacity is 202 No special provisions Interconnection with neighboring water 2 emergency water supply plans. One is Waterworks million gallons. Have a plan to system delivery of water cans to shelters. The other is Bureau increase the total storage transportation by water tank truck to shelters, capacity to 264 million gallons, medical facilities, and so on. Stockpiles of which is equivalent to 50% of various emergency equipment and materials; the immediate design maximum water tank truck, polyethylene bags for daily supply. This plan is based emergency water supply, temporary water on the direction of the Ministry tanks, and pipes, etc. of Health, Labor and Welfare. However, Osaka Waterworks didn’t actually estimate how much is necessary to supply victims. Osaka Waterworks has a plan to construct new reservoirs within the City to expand well-balanced tanks and reservoirs to be used as emergency action bases. Table 2E – page 5 419 Organization Adequate Post- Earthquake Supply? Post-Earthquake Fire Additional Emergency Water Emergency Drinking Water Fighting Provisions Evaluation Basis Tokyo No In the Japanese standard, the No special provisions. Yes with Saitama Prefecture Waterworks Emergency water supply bases placed Metropolitan distributing reservoir capacity is Tokyo Waterworks doesn't and the Kawasaki City Waterworks approximately every 1.2 miles to be reached Waterworks to secure half of the design consider fire fighting use, from any place in Tokyo to secure drinking Bureau maximum daily supply, but because the facilities scale water in case of a disaster. Tokyo Waterworks does not is large. Even if the fire have enough capacity of water fighting water is taken distribution reservoirs against from fire hydrants, the the number of customers in the water supply isn’t some region. influenced. Tottori City Don’t know Total storage capacity of No special provisions 349,000 gallons of water can be stored in 3 water trucks with 528 gallon tank and 4 earthquake resistant reservoirs is earthquake resistant distribution compact membrane filtration systems each of about 20% of daily water reservoirs which can supply 12,682 gallons of purified supply. water per day. 440 handy water containers with volume of 2.6-5.3 gallons and 25,000 emergency water bags with volume of 1.6 gallons are stored. Yokahama Yes In emergency without -Fire water supply and Interconnection with neighboring water -Underground circulating type water tanks Waterworks earthquake, we need 12 hours distribution determined utilities; Yokosuka City, Kawasaki City, used to ensure the minimum drinking water Bureau storage water volume in each using Japan Water Works and Kanagawa Prefecture. There are 10 requirements for residents in the disaster. They distribution reservoir. It is the Association Guideline receiving points. are installed at elementary and junior high standard of Japan Water Works “Design Criteria for schools, and public parks. 134 total tanks. Association Guideline. Waterworks Facilities” 15,852 gallon tanks at 118 sites, 26,420 gallon Yokahama Waterworks Bureau -Reservoirs have tanks at 11 sites, 185,000 gallon tanks at 2 distribution system has new emergency shutoff valves, sites, 264,200 gallon tank at 1 site, 343,461 target of 15 hours long. Water automatically closing gallon tank at 1 site, and 396,300 gallon tank volume of distribution reservoir when sensing earthquakes at 1 site. 3.5 million gallons total water is 249 million gallons, design more than intensity 5, but volume. maximum water supply volume continue supplying water -385 taps in the city for emergency water is 397 million gallons. 249 for post-earthquake supply distribution. divides by 397, and times 24 firefighting and other -All distribution reservoirs have emergency hours is 15.1 hours. needs until reaching the shut-valves to secure 50 million gallons water security quantity of water (security quantity of water). needed for emergency drinking water storage. Table 2E – page 6 420 Organization Adequate Post- Earthquake Supply? Post-Earthquake Fire Additional Emergency Water Emergency Drinking Water Fighting Provisions Evaluation Basis Japan Water The Ministry of Health, Labor The indicator of the Ministry of Health, The indicator of the Ministry of Health, Labor Research Center and Welfare recommends the Labor and Welfare published in the and Welfare published in the manual of Japan (Yasuhiko Sato) total minimum distribution manual of Japan Water Research Center Water Research Center is defined as follows. and reservoir capacity equal 12 is defined as follows. 1) Amount of emergency water supply per day Japan Water hours of planned daily 1) When securing emergency water one person (0.8 gallons or more) Works maximum supply amount. This supply and the city water for restoration 2) Initial emergency water supply period days Association value was announced in the long work, it is effective to perform water (about 3 days) (Kazutomo term plan for water works accommodation for a disaster system Nakamura) aiming 21 century on June 1, from other systems. 1991. 2) Therefore, strengthening of a widening backup function is promoted by maintaining wide area supply which can accommodate water over a wide area, and the transition pipe between drinking- water supply utilities. The Japan Water Works Association guideline for anti-earthquake planning (see Note 6 for Table 3) of water supply system (draft) says a connection pipeline with neighbor waterworks or another pipe system is effective for emergency supply and restoration activity. Therefore the connection pipe is strongly recommended. mgd = million gallons per day Table 2E Notes: 1. Kanagawa Water Supply Authority ( KWSA) does not have enough water stored and available to the local distribution network for a damaging earthquake. If the raw water main in Sakawa water supply system is broken, KWSA cannot intake raw water to three treatment plants in Sakawa water supply system, requiring use of other water resources. As a result, KWSA doesn't have enough ability for intaking raw water in case of earthquake. An evaluation was performed to determine a response in case of emergency as follows: First, assume earthquakes on the Kannawa and Kozu-Matuda fault belt. In this scenario, estimate the water demand of constituent waterworks from past results. The following amount of water is estimated in this scenario. (1) Can supply treated water to constituent waterworks from our three treatment plants (including transfer to another water resource), (2) Cannot supply treated water to constituent waterworks from our three treatment plants. Table 2E – page 7 421 422 Table 3E. Performance Criteria and Emergency Response Information (English units). Organization Ground Performance Criteria Restoration Time Estimate Number of Mutual Aid Alternate Forms Earthquake Materials and Failure Employees and of Assistance Equipment Hazard to Restore Assistance System Agreements? United States Alameda County High None at this time No estimate has been made 36 No None None Water District Central Utah High Currently Developing Criteria No estimate has been made 20 No None None Water (Wasatch Conservancy front) District Low (east state) Contra Costa Moderate -Temporary repairs to achieve full service 30 days 50 Yes None -Flexible hose Water District within 30 days. General earthquake scenarios -Portable generators -Water for partial service to wholesale for known faults in area. - Repair parts and valves customers within 3 days. and piping -Water for essential services to wholesale Based on modeling of - Emergency supplies customers within 15 days. anticipated damage from (food, clothing, etc.) -Water for partial service to industrial, scenario earthquake divided - Satellite radios agricultural, landscape customers within 10 by anticipated response - Emergency fuel days. effort to arrive at a total - Emergency cash - Temporary service for fire service and response time. essential services as soon as possible. - Emergency fire service within 1.5 miles for all customers within 8 hours. - Full service to all functioning emergency and critical care facilities via distribution system within 10 days. - Partial water service to all areas via distribution system within 10 days. - Essential (sanitary) service to all areas via distribution system within 15 days East Bay Varies See Note 1. 40 to 50 days 800 Yes None -pipe Municipal from Low System analyzed to -flexible large diameter Utility District to Very determine estimated return to hoses with flaking boxes High in service times following four -valves different earthquake scenarios -tunnel repair sets areas of developed for seismic -boxes for Emergency system program (see Table 2). Made Operations Team break estimates repair time Members to fix breaks and damaged facilities determined by estimating crew time to repair using historical data. Table 3E - page 1 423 Organization Ground Performance Criteria Restoration Time Estimate Number of Mutual Aid Alternate Forms Earthquake Materials and Failure Employees and of Assistance Equipment Hazard to Restore Assistance System Agreements? Los Angeles Moderate The Los Angeles Department of Water and Anticipate approximately 7 More than No, currently None at 5 district yards store: Department of Power has not specified any water system days for nearly full recovery 500 working on -food packages Water and Power seismic performance criteria after an earthquake of CALWARN -cooking utensils magnitude on the order of and East Bay -sleeping cots 6.7 based on the 1994 Municipal -blankets Northridge Earthquake Utility (no special pipe or fittings recovery. District stockpiled beyond normal agreements operation) Memphis Light Depends Memphis Light Gas and Water is in the Work in progress, specific 32 to 40 Yes Retired Purchasing department has Gas and Water on process of a multi-hazard risk assessment. restoration times not yet employees can worked out agreements location Performance goals will follow from the risk available. be called into with suppliers. assessment. service if 3 scenarios consider small, medium and large. necessary (have Small based on smallest earthquake that can used on special damage system. projects). San Francisco Varies After completion of the Water System Minor damage, within 3 Unknown, Yes None Pipe segments, fittings and Public Utilities around Improvement Program, the goals are: days, typical break, within depends on other equipment Commission system -Deliver the winter demand (82 million 14 days. Within 30 days for severity of stockpiled at strategic (S.F. City gallons/day) within 24 hours with 90% most major system extents; failure locations throughout the distribution, reliability up to 90 days for bridge and system. see * bottom of -Deliver average day demand (114 million tunnel work, depending on Table 1) gallons/day) within 30 days with 90% earthquake location. reliability Evaluations ongoing based on specific earthquakes on Hayward, Calaveras, and San Andreas faults. San Francisco Varies After completion of the Water System Minor damage, within 3 Unknown, Yes None Pipe segments, fittings and Public Utilities around Improvement Program, the goals are: days, typical break, within depends on other equipment Commission system -Deliver the winter demand (215 million 14 days. Within 30 days for severity of stockpiled at strategic (wholesale, gallons/day) within 24 hours with 90% most major system extents; failure locations throughout the see * bottom of reliability up to 90 days for bridge and system. Table 1) -Deliver average day demand (300 million tunnel work, depending on gallons/day) within 30days with 90% earthquake location. reliability Evaluations ongoing based on specific earthquakes on Hayward, Calaveras, and San Andreas faults. Table 3E - page 2 424 Organization Ground Performance Criteria Restoration Time Estimate Number of Mutual Aid Alternate Forms Earthquake Materials and Failure Employees and of Assistance Equipment Hazard to Restore Assistance System Agreements? Santa Clara High Level of service goal is potable water service -45 to 60 days for M7.9 San Unknown No, but None, but -spare pipe in diameters Valley Water at the average winter flow rate available to a Andreas earthquake. planning to planning to 20 – 120 inches District minimum of one turnout per retailer within 7 -30 to 45 days for a M6.7 obtain in near secure retainer -valves and appurtenances days. Southern Hayward future. agreements for -internal pipe joint seals earthquake. contractors to -7 to 10 days for a M6.2 perform Central Calaveras infrastructure earthquake. emergency -earthquakes were modeled repairs based on probability of occurrence Japan Chiba Prefecture Low classified goals for water supply: 28 days 500 Yes None -aluminum canned water - Waterworks (maybe) -0.8 gallons/day/person within 3 days after Would like to repair water -necessity for camping Bureau earthquake supply facilities within 4 such as tents, blankets, -5.3 gallons/ day/person from 4 days to 10 weeks, even if Hanshin sleeping bags, mats, days after earthquake earthquake grade occurs. -radios -26.4 gallons/ day/person from 11 days to 21 -Not sure if specific for days after earthquake earthquake: stockpile -66 gallons/ day/person from 22 days to 28 pipes, bends, cover joints days after earthquake Fukuoka City Low Essential water volume increases according to 4 weeks 19 normal Yes 12 work units None Waterworks the elapsed days following the earthquake. M7.1 on Kego fault. 100 skilled from private Bureau -0.8 gallons per person in 3 days Damages estimated by employees companies, -water supply increases with passing time, dividing City into 820 ft can be Fukuoka Pipe until almost fully recovered the water supply meshes, each mesh assigned available Work Company system in 4 weeks. earthquake shock. Association Hachinohe Moderate Aim for ending emergency restoration within 3 weeks 174 Yes None -water service tank Regional Water three weeks M8.2 used to calculate days -bottled water Supply needed for restoration -pipe material (ductile iron Authority pipe) Hanshin Water Moderate Emergency restoration work of damaged 1 week Yes None None Supply facilities will be completed within one week General earthquake, Authority restoration shorter than end suppliers restoration process Kanagawa Water High Goal is to restore supply water to four No estimate 433 Yes None Stockpile materials and Supply waterworks (constituent bodies) within 7 days. equipment for post- Authority earthquake restoration to continue water supply at each 40 water supply point. (e.g., portable generator, measure for chlorine, etc.) Table 3E - page 3 425 Organization Ground Performance Criteria Restoration Time Estimate Number of Mutual Aid Alternate Forms Earthquake Materials and Failure Employees and of Assistance Equipment Hazard to Restore Assistance System Agreements? Kobe Moderate Post-earthquake performance criteria are as 4 weeks 343 Yes None None Waterworks follows. Assume similar level as the See Note 3. Bureau a. Complete emergency restoration within 4 1995 Hanshin-Awaji Great weeks earthquake. b. Step-by-step provision of emergency The 1995 earthquake showed drinking water the tolerable limit for water c. Water distribution toward emergency system outage is hospitals and schools approximately four weeks. d. Deciding emergency restoration area in a See Note 2 for restoration fair order process. e. Stabilization of the people's livelihood Nagoya Moderate -First 3 days provide 0.8 gallons/person/day 4 weeks targeted, but do not Do not Yes Request Equipment in 24 material Waterworks and using mobile and central station water supply have estimate of how long it know how cooperation warehouses Sewerage to sustain life will take to restore system to many staff from retired -264 gallon water tank Bureau -4 to 10 days provide 5.3 gallons/person/day normal. will be staff (mobile type) using mobile and central station water supply available to -1 KVA dynamo for cooking and washing face and hands make -temporary hydrant (4 -11 to 21 provide 26.4 gallons/person/day repairs taps) using central station and pipeline distribution -264 gallon emergency water supply for washing cloths and bathing water supply tank -22 to 28 days provide 66 gallons/person/day -polyethylene tank (1.3, using central station and pipeline distribution 2.6, and 5.3 gallon) water supply for regular life function. -tent -Increase reliability of pipe distribution system -fire hydrant hose over time until fully restore within 28 days. -Light and tools, -pipe drawings (1/2500) Osaka Municipal High -Within 3 days from earthquake occurrence - 1 month 2,200 Yes Emergency Various emergency Waterworks Securing of drinking water for refugees (0.8 Restoration estimate based Mutual water supply equipment and materials; Bureau gallons/day/person) on calculations of how many assistance agreements with water tank truck, -Within 10 days from earthquake occurrence - teams will perform pipe or agreements the Japan Truck polyethylene bags for Securing of eating and drinking water (5.3 facilities repairs using 5 with 14 major Association and emergency water supply, gallons/day/person) earthquake scenarios. cities. a soft drink temporary water tanks, -Within 15 days from earthquake occurrence - maker. and pipes, etc. Securing of subsistence water (26.4 gallons/day/person) -Within a month from earthquake occurrence- Securing of daily life water (66 gallons/day/person) Table 3E - page 4 426 Organization Ground Performance Criteria Restoration Time Estimate Number of Mutual Aid Alternate Forms Earthquake Materials and Failure Employees and of Assistance Equipment Hazard to Restore Assistance System Agreements? Tokyo High -The supply routes to the capital center 30 days 500 Yes Constructor Tokyo Waterworks Metropolitan organizations are restored within three days -M6.9 and M7.3 Tokyo Bay Agreements secures all the restoration Waterworks after the earthquake occurs. Northern part Earthquakes; materials of the supply Bureau -other water supply facilities are restored and M6.9 and M7.3 Tama routes such as the capital within 30 days inland Earthquake. The center organizations, and hypocenter depths were 19- provides to the 31 miles, respectively. constructors. -The water suspension rate is calculated for 820 ft mesh in consideration of pipe length, material and caliber, liquefaction, and ground speed. Tottori City High After 2-3 days: Emergency water supply by 3 or 4 weeks 30 Yes Assistance None using stored water Earthquake JMA seismic agreements with After 4 days: Direct water supply to important intensity 6. cooperative facilities with emergency supply pipelines Estimation by total predicted water works After 21 to 28 days: restore system completely number of pipe damages and association in ability of repair parties. the City. Estimate 1.6-2.4 pipe breakages per km, 250 of transmission and distribution pipes and 700 of supply pipes. Yokahama High See Note 4. After earthquake until third day, 28 days 300 Yes The union of Stockpile materials and Waterworks called the confusion period, Yokahama -Yokahama Waterworks Prepares to pipe equipment at 14 sites in Bureau Waterworks supplies water to residents by the estimates for major accept the construction the city and through underground circulating type water tanks and earthquake based on support from company's mutual assistance stored water in the distribution reservoirs. One earthquake disaster example cities not members repairs agreements. person can use 0.8 gallons/day. After that until that happened in other cities. affected by broken pipes -DIP and service pipe seventh day, called the primary restoration disaster and and will work material, bottled water, period, the residents receive water from between these with employees. portable tank, power emergency water supply taps. One person can cities, carries generator, fuel, emergency use 2.6 gallons/day. After that until fourteenth out disaster water supply tap, battery day, called the secondary restoration period, prevention charger, pump, hand the residents receive water from emergency training twice operation pump, simple water supply distribution stations and a year filter machine, radio temporary water tap. One person uses 5.3 facilities gallons/day. After that, called the revival period, one person uses 26.4 gallons/day. Table 3E - page 5 427 Organization Ground Performance Criteria Restoration Time Estimate Number of Mutual Aid Alternate Forms Earthquake Materials and Failure Employees and of Assistance Equipment Hazard to Restore Assistance System Agreements? Japan Water The Ministry of Health, Labor and Welfare 28 days is in the guideline See Note 6. Works has the standard of water works facilities that for anti-earthquake planning Association Japanese call the performance criteria. Japan of water supply system (Kazutomo Water Works Association published the (draft) that is supervised by Nakamura) design criteria for water works facilities and the Ministry of Health, and the earthquake-resistant design criteria for Labor and Welfare and Japan Water water works facilities that most of Japanese published by the Japan Research Center water works use for designing their facilities. Water Research Center. (Yasuhiko Sato) The restoration goal should be within 4 weeks (28 days) if possible, to decrease fear of sufferer and stabilized their daily life. See Note 5. Table 3E Notes: 1. East Bay Municipal Utility District Service Level Goals Service category Operating Earthquake Maximum Earthquake General -Minimal secondary damage and risk to the public -Minimal secondary damage and risk to the public -Limit extensive damage to system facilities -Limit extensive damage to system facilities -All water introduced into distribution system minimally disinfected, using -All water introduced into distribution system minimally disinfected Orinda and Walnut Creek treatment plants -All water introduced into the distribution system fully treated -All water introduced into the distribution system fully treated Fire Service -Sufficient portable pumps to provide limited fire service in all areas -Sufficient portable pumps to provide limited fire service in all high risk areas -All areas have minimal fire service (one reliable pumping plant and reservoir) -All areas have minimal fire service (one reliable pumping plant and reservoir) -High risk areas have improved fire service (at facilities reliable, minimum fire -High risk areas have improved fire service (at facilities reliable, minimum fire reserves) reserves) -Service to all hydrants within 20 days -Service to all hydrants within 100 days Hospitals and Disaster -Minimum service to all affected areas within 1 day (water available via -Minimum service via distribution system or truck within 3 days Collection Centers backbone distribution system near each facility) -Impaired service to affected area within 3 days (water available via -Minimum service within 10 days (water available via backbone distribution distribution system to each facility, possibly at reduced pressures) system near each facility) Domestic Users -Potable water via distribution system within 1 day -Impaired service within 30 days (water available via distribution system to -Impaired service to affected area within 3 days (water available via each domestic user, possibly at reduced pressures) distribution system to each domestic user, possibly at reduced pressures) -Potable water at central locations for pick up within 3 days -Minimum service to 70% of customers within 10 days Commercial Industrial, -Impaired service to affected area within 3 days (water available via -Potable water at central locations for pick up within 1 week and other Users distribution system to each commercial or industrial user, possibly at reduced -Minimum service to 70% of customers within 10 days pressures) -Impaired service to 90% of customers within 30 days 2. Kobe restoration scenario is as follows: 1st run the water through the pipes to find leakage. This requires restoration to be completed one by one downstream from the transmission tunnels branch connections, even with plenty of human resources. Using multiple sources to the distribution pipe network (such as Large Capacity Transmission Main, Emergency Contact Pipes, and Prefecture Water), in addition to the existing transmission tunnels, we can find the leakage and repair them in several directions at the same time. 2nd isolate a pipe block by shutting valves from others to easily find the leakage in the block. The work force leveling in every stage is concerned with reduction of the restoration period. Kobe Waterworks Bureau is trying to simulate those processes with several assumptions on seismic practices, water sources, new transmission systems, and so on. The population distribution and demographics in Kobe have been floating since the 1995 earthquake, but they have become stable gradually; in consideration of this the recovery period is being re-examined. Table 3E - page 6 428 3. Kobe Waterworks Bureau has mutual aid agreements for disasters in a group of 15 large cities as well as with nearby local cities. Those agreements include both providing emergency drinking water for customers and repairing the damaged water system. Extensive damage predicted for the great offshore earthquake expected in the near future. In such occasion, the neighboring governments also may suffer, and Kobe may not be able to expect aid from them. Therefore, it is very important to have a mutual aid agreement among 15 large cities in Japan. In the case of Kobe City, Osaka City and Hiroshima City are assigned as the mutual aid city. 4. Yokahama Waterworks Bureau performance criteria Time progress 8 hrs 16 hrs 24 hrs 2 – 3 days 4-7 days 8-14 days 15-28 days Distributed drinkable water volume 0.8 gallon/day/person 0.8 gal/d/p 2.6 gal/d/p 5.3 gal/d/p 26.4 gal/d/p Transportation water supply by vehicle to hospitals XXXXXXXX XXXXX XXXXX XXXXX Transportation water supply by vehicle to refuge places XXXXX XXXXX XXXXX Share water of Distribution Reservoir’s water XXXXXXXXXXXX XXXXX XXXXX XXXXX Share water of Underground Circulation Type Water Tank’s water XXXXXXXXXX XXXXX Distribution water from Emergency Water Supply Tap YYYYY XXXXX XXXXX XXXXXX Distribution water from Temporary Water Supply Pipeline YYYYY XXXXX XXXXXX Distribution water from Water Supply Pipeline YYYYY YYYYY YYYXXX 5. Japan Ministry of Health, Labor and Welfare restoration performance goals published by the Japan Water Research Center: Period Quantity Carry Distance Supply Methods 0-3 days 0.8 gallons/person/day within 3280 ft anti-seismic tank, emergency tank, water trucks 10 days 5.3 gallons/person/day within 820 ft temporary tap near trunk main 21 days 26.4 gallons/person/day within 328 ft temporary tap near lateral main 28 days normal amount as before earthquake within 33 ft temporary tap to each house 6. Japan Water Works Association has the report of emergency response for water supply system. Just after the Kobe earthquake, the committee set up and studied the emergency response procedure. The contents of report are: a) basic rule of assistance request b) communication procedure c) about expenditure and accident, etc d) organization of assistance team e) manual for assistance activity f) manual for restoration g) assistance activity in field h) publicity and public relations i) recording of activities j) sample of mutual assistance agreement. Table 3E - page 7 429 430 Table 1M. System General Information (metric units). Organization Service Population Service Pipe Length Pipe Total Storage Number of Storage Size 3 3 (survey Connections (km) Diameter Capacity (m ) Tanks and Range (m ) responder) Range Reservoirs Type Region Area See Table 1a See Table 1a (mm) (km2) United States Alameda County Distributor Cities of 267 324,800 78,150 total 1,401 total 51 – 1,219 340,650 13 total 1,893 to Water District Fremont, 69,000 sf 1 ci 7 tanks 79,485 (Threse Newark, and 2,020 mf 99 s 6 in-ground Wooding) Union City, 3,480 c/i/g 136 p reservoirs California 1,830 LI 629 ac 1,820 fh 6 O Central Utah Wholesaler 10 counties 1,200,000 Wholesale to 25 129 total 457 – 3,048 189,250 6 tanks 2,877 to Water service 80 s 8 raw water 75,700 Conservancy providers 2 P301S reservoirs District (David 8 RC Pitcher) 39 tunnels Contra Costa Distributor Central and 554 270,000 88,000 total 1,271 total 51 – 2,438 283,875 40 946 to 26,495 Water District Eastern 53,000 sf 21 ci (Steve Welch) Contra 30,500 mf 42 di Costa 4,000 c/i/g 214 s County, 500 A/I (raw) 298 p California 500 R 692 ac East Bay Distributor Portions of 842 1,300,000 403,402 total 6,656 total 51 – 2,743 2,952,300 170 11 to 582,890 Municipal Alameda 320,478 sf 2,190 ci treated water Utility District and Contra 29,277 mf 3 di (Bill Cain) Costa 4,697 A/I 1,987 s Counties, 48,950 O 585 p California 1,844 ac 17 PCCP 123 RCCP 1 copper 4 wrought iron 1 O Los Angeles Distributor City of Los 1,204 4,050,000 712,351 total 11,632 total 51 – 3,658 18,760,235 108 potable 6.4 to Department of Angeles, 614,253 sf+mf 7627 ci potable water 12,542,423 Water and Power California 83,744 c/i/g 1139 di 4 raw water (Craig Davis) 631 O 1,044 s 30,075,148 raw (emergency 0.6 p (stored in the storage only) 610 ac distribution 83 concrete system area) 28 copper 16 O Table 1M – page 1 431 Organization Service Population Service Pipe Length Pipe Total Storage Number of Storage Size 3 3 (survey Connections (km) Diameter Capacity (m ) Tanks and Range (m ) responder) Range Reservoirs Type Region Area See Table 1a See Table 1a (mm) (km2) Memphis Light Distributor City of 1,834 850,000 253,759 total 5,908 total 51 – 914 467,448 34 379 to 56,775 Gas and Water Memphis 228,656 res 5,887 ci+di (Fred von Hofe) unincorpor- 19,924 c/i/g 1.3 s ated areas of 5,179 O 6.4 p Shelby Co., Cities of Arlington & Lakeland, Tennessee San Francisco Distributor* City of San 122 770,000 Approximately 2,011 total 19 – 1,981 1,570,775 21 284 to Public Utilities Francisco, 250,000 total Consisting 338,379 Commission* California mainly of ci, (Luke Cheng) some ci being replaced with di San Francisco Wholesaler* 28 agencies 6,515 1,700,000 150 turnouts to 1,920 total 711 – 2438 3,607,105 24 3,785 to Public Utilities in San residential, Bay Area Water Consisting 2,504,156 Commission* Francisco commercial, Supply and mainly of s, (Luke Cheng) Bay area, and industrial Conservation RCCP, PCCP California users District agencies Santa Clara Wholesaler Santa Clara 502 1,700,000 45 total 241 total 500 – 3,048 209,670,302 10 raw 492,050 to Valley Water County, 18 A/I 60 s Mostly raw 1 treated 109,765,000 District (Erin California 27 wholesale 174 PCCP water not usable (raw) Baker) retailer turnouts 7 RCCP for earthquake 56,775 response (treated) Japan Chiba Prefecture Distributor 11 cities and 564 2,830,000 unknown 8,438 total 50 – 1,800 770,000 3,000 to Waterworks 2 towns 8,015 di 60,000 Bureau (Shigeru (Chiba, 169 s Hataya) Funabashi, 17 ac Matsudo, 237 HIVP Ichikawa, -replaced 2,300 Ichihara, km ac Narashino, Urayasu, Shiroi, Inzai, Narita, Imba, Motono) Table 1M – page 2 432 Organization Service Population Service Pipe Length Pipe Total Storage Number of Storage Size 3 3 (survey Connections (km) Diameter Capacity (m ) Tanks and Range (m ) responder) Range Reservoirs Type Region Area See Table 1a See Table 1a (mm) (km2) Fukuoka City Distributor Fukuoka 235 1,402,200 736,380 total 3,778 total 40 – 1,800 366,100 45 (17 sites) 60 to 22,400 Waterworks City unknown sf 145 ci Bureau (Kuniaki unknown mf 3,582 di Nakamura) 64,062 c/i/g 38 s 98 A/I (other 3 p system) 1,592 R Hachinohe Distributor 1 city 801 336,276 131,642 total 1,819 total 75 – 1,500 110,602 47 56 to 10,000 Regional Water (Hachinohe) 122,212 sf + mf 35 ci Supply 6 towns 9,430 c/i/g 1,490 di Authority (Oirase, 9 s (Norbou Gonohe, 207 p Murakami) Rokunohe, 78 ac Hashikami, Nanbu, Sannohe) Hanshin Water Wholesaler Kobe, 478 2,500,000 21 supply points 126 total 300 – 2,400 262,800 15 1,300 to Supply Ashiya, Kobe (6), 11 ci 80,000 Authority (Shinji Nishinomiya Ashiya (4), 53 di Nakayasu) and Nishinomiya (8) 39 s Amagasaki Amagasaki (3) 1 ac Cities 22 tunnel Kanagawa Water Wholesaler Kanagawa 1,489 8,007,450 40 supply points 199 total 800 – 2,800 536,600 17 5,000 to Supply Prefectural, total for 4 59 di 60,000 Authority (Ken- Yokohama constituent waterworks 107 s ichi Koike) City, waterworks 33 di + s Kawasaki has 50% City, and dependence Yokosuka on KWSA City water Kobe Distributor Kobe City 553 1,523,521 744,592 total 4,906 total 50 – 2,400 563,120 251 (123 30 to 39,000 Waterworks 700,910 sf+mf+ 1,407 ci sites) Bureau school+hospital 3,092 di (Kizuhiko 444 ABK 230 s Mizuguchi) 74 pbh 177 p 43,164 o/f Nagoya Distributor Nagoya City 356 2,316,000 793,208 total 8,054 total 16 – 2,000 634,589 43 29 to 50,000 Waterworks and 501,539 sf 228 ci Sewerage 67,487 mf 5,108 di Bureau (Yukio 224,182 c/i/g 37 s Mabuchi) 2,676 p 4 O Table 1M – page 3 433 Organization Service Population Service Pipe Length Pipe Total Storage Number of Storage Size 3 3 (survey Connections (km) Diameter Capacity (m ) Tanks and Range (m ) responder) Range Reservoirs Type Region Area See Table 1a See Table 1a (mm) (km2) Osaka Municipal Distributor Osaka City 211 2,600,000 925,000 total 5,000 total 75 – 2,000 765,700 10 500 to Waterworks 411,000 sf 830 ci 100,900 Bureau (Hiroaki 369,000 mf 4,100 di Miyazaki) 144,000 c/i/g+R 70 s Tokyo Distributor Tokyo City 1,222 12,246,523 6,550,765 total 25,262 total 50 – 2,700 3,293,393 176 3 to 286,800 Metropolitan (2005 FY) 6,328,931 sf 370 ci Waterworks 220,911 mf 24,509 di Bureau (Masaru 923 pbh 356 s Oneda) 217 O 26 p 1 ac Tottori City Distributor Tottori City 98 150,000 49,000 total 1120 total 20 – 1,200 43,000 31 200 to 10,000 (Prof. Yosihiko 27 ci Hosoi) 748 di 24 s 320 p Yokahama Distributor Yokahama 435 3,623,795 1,696,549 total 8,993 total 75 – 2,000 967,700 39 (23 sites) 5,800 to Waterworks City 1,696,549 sf+mf 6,401 ci + di 136,000 Bureau (Ken 68,838 c/i/g 1,771 s Yokoyama) 124 pbh 817 p 4 concrete *San Francisco Public Utilities Commission (SFPUC) is responsible for water distribution to the City of San Francisco and wholesale supply to suburban agencies in portions of Alameda, Santa Clara, and San Mateo Counties represented by the Bay Area Water Supply and Conservation District (www.bawsca.org). For purposes of tabulation, the distribution and wholesale portions of SFPUC are presented separately for better comparison. Although the SFPUC system cannot be completely separated into two independent systems, for tabulation purposes information for SFPUC wholesale for the most part does not account the City of San Francisco distribution, and vice versa. The SFPUC is tabulated in two parts because the distribution component of SFPUC is similar to the Los Angeles Department of Water and Power, East Bay Municipal Utility District, and others who have their own aqueduct supplies but are not considered wholesalers to themselves and the wholesale component of SFPUC is similar to Santa Clara Valley Water District, Hanshin Water Supply Authority, and others who do not distribute water directly to customers. Table 1a. Service Connection and Pipe Type abbreviations. Service Connection Pipe Type sf = single family dwellings ci = cast iron mf = multi-family dwellings di = ductile iron res = residential s = steel c/i/g = commercial/industrial/government p = plastic (e.g. PVC) A/I = Agriculture/Irrigation O = Other R = Recreational ac = asbestos cement O = Other PCCP = Prestressed Concrete Cylinder Pipe LI = Landscape Irrigation RCCP = Reinforced Concrete Cylinder Pipe fh = firelines and hydrant RC = Reinforced Concrete pbh = public bath houses P301S = Prestressed 301 Steel ABK = Apartments sharing Bath and Kitchen o/f = offices/factories Table 1M – page 4 434 Table 2M. Earthquake Water Supply Information (metric units). Organization Adequate Post-Earthquake Supply? Post-Earthquake Fire Additional Emergency Water Emergency Drinking Water Fighting Provisions Evaluation Basis United States Alameda County Don’t know No special provisions at No special provisions at this time No special provisions at this time Water District this time Central Utah Don’t know Water Conservancy District Contra Costa Yes (for Fragility analysis performed – No special provisions 10 emergency interconnections [with Contra Costa Water District is responsible for Water District emergency results used to implement East Bay Municipal Utility District (2 public drinking water response. No other plans demands seismic improvement program treated, 1 raw), Cities of Martinez (2), in place in the event Contra Costa Water not normal focused on rapid recovery. Pittsburg (2), Antioch, Brentwood, and District’s system is insufficient. demand) Diablo Water District] totaling 389,855 m3/day treated and 378,500 m3/day untreated. East Bay Yes East Bay Municipal Utility Terminal storage Inter-connections with the San Francisco Will follow regional office of Emergency Municipal District performed systematic reservoirs Public Utilities Commission and Contra Services directions Utility District evaluation of distribution system 203,504 m3 loaded by Costa Water District capable of using Monte Carlo simulation of helicopter for fighting supplying 113,550-189,250 m3/day. 4 scenario earthquakes ranging urban-wild land interface from an operating earthquake of fires. M6.0 on Hayward fault to maximum credible events of M7.0 Hayward fault, M6.75 Calaveras fault, and M6.5 Concord fault. The damage that occurred in the simulations was used to guide development of a 10-year Seismic Improvement Program (recently completed) in which facilities and pipelines contributing to overall post- seismic system performance were fixed. Table 2M – page 1 435 Organization Adequate Post-Earthquake Supply? Post-Earthquake Fire Additional Emergency Water Emergency Drinking Water Fighting Provisions Evaluation Basis Los Angeles Yes No specific evaluation has been -No added fire storage -The Los Angeles Department of Water - Los Angeles Department of Water and Department of performed. The Los Angeles volume. and Power can utilize more than 25 Power has a plan to provide drinking water Water and Power Department of Water and Power -Inter-system connections Metropolitan Water District of Southern emergency water distribution stations. A has historically maintained a allow fire engine pumping California (wholesale supplier) station will consist of one or more 1.3 m3 large volume of water supply in units to pump from a connections to receive additional potable water storage bladders and PVC pipe the distribution network that lower pressure to higher supplies. manifold with dispensing spigots, set up on a aided the system recovery pressure zone through -The Los Angeles Department of Water pair of extra strong aluminum folding tables. during the 1971 San Fernando adjacent fire hydrants. and Power has a few small connections 50 bladder-manifold kits are stored in a sealed and 1994 Northridge -Helistops at reservoir and other municipal water agencies (Beverly steel drum to keep it clean and ready for use Earthquakes. The assumption is mountainous regions (e.g., Hills, Long Beach, Inglewood El and stand at 6 district yards around the City. that this supply will be adequate Elysian Park) Segundo, Las Virgenes, Los Angeles -When deployed, the stations will be in future earthquakes. -Fire fighters take County Waterworks District No. 29), repeatedly filled by potable water tender advantage of swimming primarily to provide water to them, tankers. Los Angeles Department of Water pools as added supply however it may be possible for the Los and Power plans to purchase, store and (this is a usable supply, Angeles Department of Water and Power maintain in a ready state two stainless steel but not specifically to receive some water from these tanker trailers of 14 m3 capacity each, as a identified as an alternate agencies in an emergency. means of immediate first response. Additional supplemental supply for tankers will be employed as needed fire suppression). through spot rental and mutual aid. Memphis Light Yes Currently having this checked Maintain 30,280 – Have interconnections with a number of Unlike most systems Memphis Light Gas and Gas and Water by consultant 113,550 m3/day plants at small systems that could be used on Water has 8 major plants and anticipates different locations, if one emergency basis. several plants will survive a major earthquake. fails others can pick up Water from operating plants available for fire load if distribution system fighting, sanitation, and drinking. functions. San Francisco Yes Levels of Service (LOS) Goals 1,514,000 m3 domestic Interconnections with East Bay Approximately 70 potable water hydrants Public Utilities following completion of the supply; an additional Municipal Utility District and Santa throughout the City of San Francisco are Commission Water System Improvement 757,000 m3 non-potable Clara Water District allow water sharing marked with a blue water drop, and serve as (S.F. City Program (WSIP) in 2014: fire suppression reserves capacity up to 264,950 m3/day. emergency water distribution sites following distribution, in cisterns, local lakes, an earthquake or other disaster. They will be see * bottom of Deliver minimum system untreated reservoirs, etc. manned by San Francisco Public Utilities Table 1) demand (winter month demand) Commission crews and neighborhood within 24 hours after a major The San Francisco Fire emergency response teams following a earthquake. Minimum winter Department maintains an disaster. Additionally, the San Francisco Zoo month demand is estimated at auxiliary water supply Well serves as an emergency potable water 813,775 m3/day in 2030. system independent of the supply. The Zoo Well project includes a truck water distribution system fill station, disinfection facilities, upgrade of Deliver average demand under and dedicated only to fire the existing power system for the well, and an the condition of one unplanned fighting. emergency generator. outage concurrent with one planned outage of major facilities. Average demand in 2030 is estimated at 1,135,500 m3/day. Table 2M – page 2 436 Organization Adequate Post-Earthquake Supply? Post-Earthquake Fire Additional Emergency Water Emergency Drinking Water Fighting Provisions Evaluation Basis San Francisco Yes LOS Goals following WSIP Local lakes and reservoirs; Interconnections with East Bay Varies by wholesale customer/jurisdiction. Public Utilities contingency plans and Municipal Utility District and Santa Some can use groundwater. Commission At least 70 percent of the emergency storage vary Clara Valley Water District allow water (wholesale, turnouts within each region by wholesale customer/ sharing capacity up to 264,950 m3/day. see * bottom of should receive flow to achieve jurisdiction. Table 1) minimum month demand for the Other provisions vary by wholesale region. Estimated 2030 customer/jurisdiction. minimum month demands for the three regions noted above are 363,3600 m3/day, 140,045 m3/day, and 310,370 m3/day respectively. Restore facilities to meet average demand within 30 days after a major earthquake . Santa Clara No Modeled seismic hazard events No special provisions -Interconnection with San Francisco No special provisions Valley Water to determine water supply Public Utilities Commission District infrastructure reliability. -Planned future well fields for emergency Although the Santa Clara Valley supplies Water District (District) has enough raw water storage, the Infrastructure Reliability Project found that the District would not likely be able to treat and deliver the water following a seismic event due to treatment plant damage and numerous pipe breaks and leaks. The District has available groundwater and is implementing a project that will provide wells for emergency water supply. Table 2M – page 3 437 Organization Adequate Post-Earthquake Supply? Post-Earthquake Fire Additional Emergency Water Emergency Drinking Water Fighting Provisions Evaluation Basis Japan Chiba Prefecture Yes Installed emergency stop valves No special provisions Supply provided to Chiba Prefecture -10 water supply trucks with 2-4 m3 Waterworks in the distribution reservoirs up Waterworks Bureau by 2 wholesale water -69 water tanks with 1 m3 Bureau to 430,000 m3 storage capacity. supply authorities totaling about 230,000 -50,000 aluminum canned water The remaining 340,000 m3 can m3/day. If the two water supply -1,775 water tanks with 20 liters flow for domestic and fire authorities remain operable after -60,000 water supply bags with 6 to 10 liters fighting use. earthquake, they can supply 30,000 to -Emergency faucets and fire hydrants in 5 50,000 m3/day more than usual. purification plants and 14 treated pump stations used to distribute water, once water restored to those plants and stations. -Emergency water brought to refuge places and medical care institutions with the aid of Water Piping Construction Cooperative Society, before other municipal water supply entities come to aid. Support agreement maintained with Society for emergency water. Fukuoka City Yes The essential water volume in No special provisions, but 2 connections with the water wholesale Anti-earthquake pipe lines used for important Waterworks the first stage on the emergency system designed with agency, one connection with neighboring distribution lines connecting trunk line to Bureau is estimated 3 liters per person. seismic resistant ductile city in order to assist each other in evacuation sites. Also have two water carrier It means the essential total daily iron pipe so many emergencies. vehicles to supply drinkable water to water volume sum up to 2,800 m3, hydrants on distribution suspended areas. which is far smaller than pipe can be available for existing storage capacity. fire fighting. Hachinohe No Because maintenance of the No special provisions No special provisions Emergency water obtained from fire-plug and Regional Water block distribution system is seismic storage tank. Drinking water Supply insufficient, mutual flexibility is prioritized and transported to medical Authority impossible. Therefore, when the institutions and to the elementary schools used earthquake damage happens, for refuge. Standard is 3 liters/day/person. As enough water cannot be emergency repair advances the amount of the supplied to the customer. water offered from distribution network is increased. Hanshin Water No Have not performed an No special provisions Have 4 emergency water supply facilities No plan, in the business of wholesale water Supply evaluation because this supply, but will support customers. Authority organization is in the business of wholesale supply to distributing organizations Kanagawa Water No See Note 1. No special provisions. Have interconnection raw water main Kanagawa Water Supply Authority is a bulk Supply Cannot prepare counter- between two different water resources. water supplier, but can supply drinking water Authority measures for earthquake to 4 waterworks (constituent bodies) at main scenarios because fault reservoirs. Kanagawa Water Supply Authority positions cannot be clearly trains for emergency supply with constituent identified. bodies every year. Table 2M – page 4 438 Organization Adequate Post-Earthquake Supply? Post-Earthquake Fire Additional Emergency Water Emergency Drinking Water Fighting Provisions Evaluation Basis Kobe No, but are Planning emergency storage of -The emergency water Emergency connections with neighboring An emergency system provides storage every Waterworks in progress 3 liters/person/day. Will soon storage system developed water suppliers; 7 pipes with 5 cities. Up 2 km radius for efficient conveyance of Bureau of creating have enough storage up to 7- for drinking water supply to 8,000 m3 of water can be delivered in drinking water supply trucks. 47 sites cover enough days. would also be used for fire emergency situation. the whole city. 37 systems are completed at emergency fighting. present, and emergency water is secured about storage Supply for full recovery -Fire Department built and 54,000 m3. See also Note 2 for Table 3. dependent upon other sources. maintain 252 earthquake Kobe only has 25% of it own resistant water supply Store several types of carrying containers for water sources. cisterns for emergency fire emergency use in seven branch offices. fighting. 25,300 m3 total -11,240 back pack water bags (6 liters) volume. -10,249 water tank container (2 -18 liters) Nagoya No Nagoya Waterworks has Nagoya Fire Fighting 11 Emergency connections with 7 200 emergency water supply facilities located Waterworks and sufficient total water supply Bureau constructed 568 neighboring waterworks for total of so all residents can reach on foot. Sewerage after upgrading water reservoirs. earthquake resistance fire 68,300 m3/day. 208 underground hydrants installed in Bureau The total purified water storage prevention water tanks in distribution pipes leading to elementary capacity is 634,589 m3, 2006. schools that are used as evacuation sites. indicating that water supply of 12 hours or more with respect to a design daily maximum water supply volume of 1,244,000 m3 is secured. However, there is still a problem of resolving the regionally uneven distribution that exists in the amount of water stored. Osaka Municipal No Total storage capacity is No special provisions Interconnection with neighboring water 2 emergency water supply plans. One is Waterworks 765,700 m3. Have a plan to system delivery of water cans to shelters. The other is Bureau increase the total storage transportation by water tank truck to shelters, capacity to 1,000,000 m3, which medical facilities, and so on. Stockpiles of is equivalent to 50% of the various emergency equipment and materials; immediate design maximum water tank truck, polyethylene bags for daily supply. This plan is based emergency water supply, temporary water on the direction of the Ministry tanks, and pipes, etc. of Health, Labor and Welfare. However, Osaka Waterworks didn’t actually estimate how much is necessary to supply victims. Osaka Waterworks has a plan to construct new reservoirs within the City to expand well-balanced tanks and reservoirs to be used as emergency action bases. Table 2M – page 5 439 Organization Adequate Post-Earthquake Supply? Post-Earthquake Fire Additional Emergency Water Emergency Drinking Water Fighting Provisions Evaluation Basis Tokyo No In the Japanese standard, the No special provisions. Yes with Saitama Prefecture Waterworks Emergency water supply bases placed Metropolitan distributing reservoir capacity is Tokyo Waterworks doesn't and the Kawasaki City Waterworks approximately every 2 km to be reached from Waterworks to secure half of the design consider fire fighting use, any place in Tokyo to secure drinking water in Bureau maximum daily supply, but because the facilities scale case of a disaster. Tokyo Waterworks does not is large. Even if the fire have enough capacity of water fighting water is taken distribution reservoirs against from fire hydrants, the the number of customers in the water supply isn’t some region. influenced. Tottori City Don’t know Total storage capacity of No special provisions 1,320 m3 of water can be stored in 3 water trucks with 2 m3 tank and 4 compact earthquake resistant reservoirs is earthquake resistant distribution membrane filtration systems each of which about 20% of daily water reservoirs can supply 48 m3 of purified water per day. supply. 440 handy water containers with volume of 10-20 liters and 25,000 emergency water bags with volume of 6 liters are stored. Yokahama Yes In emergency without -Fire water supply and Interconnection with neighboring water -Underground circulating type water tanks Waterworks earthquake, we need 12 hours distribution determined utilities; Yokosuka City, Kawasaki City, used to ensure the minimum drinking water Bureau storage water volume in each using Japan Water Works and Kanagawa Prefecture. There are 10 requirements for residents in the disaster. They distribution reservoir. It is the Association Guideline receiving points. are installed at elementary and junior high standard of Japan Water Works “Design Criteria for schools, and public parks. 134 total tanks. 60 Association Guideline. Waterworks Facilities” m3 tanks at 118 sites, 100 m3 tanks at 11 sites, Yokahama Waterworks Bureau -Reservoirs have 700 m3 tanks at 2 sites, 1000 m3 tank at 1 site, distribution system has new emergency shutoff valves, 1300 m3 tank at 1 site, and 1500 m3 tank at 1 target of 15 hours long. Water automatically closing site. 13,380 m3 total water volume. volume of distribution reservoir when sensing earthquakes -385 taps in the city for emergency water is 967,700 m3, design maximum more than intensity 5, but supply distribution. water supply volume is continue supplying water -All distribution reservoirs have emergency 1,540,000 m3. 967,700 divides for post-earthquake shut-valves to secure 190,200 m3 water by 1,540,000, and times 24 firefighting and other (security quantity of water). hours is 15.1 hours. needs until reaching the security quantity of water needed for emergency drinking water storage. Table 2M – page 6 440 Organization Adequate Post-Earthquake Supply? Post-Earthquake Fire Additional Emergency Water Emergency Drinking Water Fighting Provisions Evaluation Basis Japan Water The Ministry of Health, Labor The indicator of the Ministry of Health, The indicator of the Ministry of Health, Labor Research Center and Welfare recommends the Labor and Welfare published in the and Welfare published in the manual of Japan (Yasuhiko Sato) total minimum distribution manual of Japan Water Research Center Water Research Center is defined as follows. and reservoir capacity equal 12 is defined as follows. 1) Amount of emergency water supply per day Japan Water hours of planned daily 1) When securing emergency water one person (3 liters or more) Works maximum supply amount. This supply and the city water for restoration 2) Initial emergency water supply period days Association value was announced in the long work, it is effective to perform water (about 3 days) (Kazutomo term plan for water works accommodation for a disaster system Nakamura) aiming 21 century on June 1, from other systems. 1991. 2) Therefore, strengthening of a widening backup function is promoted by maintaining wide area supply which can accommodate water over a wide area, and the transition pipe between drinking- water supply utilities. The Japan Water Works Association guideline for anti-earthquake planning (see Note 6 for Table 3) of water supply system (draft) says a connection pipeline with neighbor waterworks or another pipe system is effective for emergency supply and restoration activity. Therefore the connection pipe is strongly recommended. Table 2M Notes: 1. Kanagawa Water Supply Authority ( KWSA) does not have enough water stored and available to the local distribution network for a damaging earthquake. If the raw water main in Sakawa water supply system is broken, KWSA cannot intake raw water to three treatment plants in Sakawa water supply system, requiring use of other water resources. As a result, KWSA doesn't have enough ability for intaking raw water in case of earthquake. An evaluation was performed to determine a response in case of emergency as follows: First, assume earthquakes on the Kannawa and Kozu-Matuda fault belt. In this scenario, estimate the water demand of constituent waterworks from past results. The following amount of water is estimated in this scenario. (1) Can supply treated water to constituent waterworks from our three treatment plants (including transfer to another water resource), (2) Cannot supply treated water to constituent waterworks from our three treatment plants. Table 2M – page 7 441 442 Table 3M. Performance Criteria and Emergency Response Information (metric units). Organization Ground Performance Criteria Restoration Time Estimate Number of Mutual Aid Alternate Forms Earthquake Materials and Failure Employees and of Assistance Equipment Hazard to Restore Assistance System Agreements? United States Alameda County High None at this time No estimate has been made 36 No None None Water District Central Utah High Currently Developing Criteria No estimate has been made 20 No None None Water (Wasatch Conservancy front) District Low (east state) Contra Costa Moderate -Temporary repairs to achieve full service 30 days 50 Yes None -Flexible hose Water District within 30 days. General earthquake scenarios -Portable generators -Water for partial service to wholesale for known faults in area. -Repair parts and valves customers within 3 days. and piping -Water for essential services to wholesale Based on modeling of -Emergency supplies customers within 15 days. anticipated damage from (food, clothing, etc.) -Water for partial service to industrial, scenario earthquake divided -Satellite radios agricultural, landscape customers within 10 by anticipated response -Emergency fuel days. effort to arrive at a total -Emergency cash -Temporary service for fire service and response time. essential services as soon as possible. -Emergency fire service within 2.4 km for all customers within 8 hours. -Full service to all functioning emergency and critical care facilities via distribution system within 10 days. -Partial water service to all areas via distribution system within 10 days. -Essential (sanitary) service to all areas via distribution system within 15 days East Bay Varies See Note 1. 40 to 50 days 800 Yes None -pipe Municipal from Low System analyzed to -flexible large diameter Utility District to Very determine estimated return to hoses with flaking boxes High in service times following four -valves different earthquake scenarios -tunnel repair sets areas of developed for seismic -boxes for Emergency system program (see Table 2). Made Operations Team break estimates repair time Members to fix breaks and damaged facilities determined by estimating crew time to repair using historical data. Table 3M - page 1 443 Organization Ground Performance Criteria Restoration Time Estimate Number of Mutual Aid Alternate Forms Earthquake Materials and Failure Employees and of Assistance Equipment Hazard to Restore Assistance System Agreements? Los Angeles Moderate The Los Angeles Department of Water and Anticipate approximately 7 More than No, currently None at 5 district yards store: Department of Power has not specified any water system days for nearly full recovery 500 working on -food packages Water and Power seismic performance criteria after an earthquake of CALWARN -cooking utensils magnitude on the order of and East Bay -sleeping cots 6.7 based on the 1994 Municipal -blankets Northridge Earthquake Utility (no special pipe or fittings recovery. District stockpiled beyond normal agreements operation) Memphis Light Depends Memphis Light Gas and Water is in the Work in progress, specific 32 to 40 Yes Retired Purchasing department has Gas and Water on process of a multi-hazard risk assessment. restoration times not yet employees can worked out agreements location Performance goals will follow from the risk available. be called into with suppliers. assessment. service if 3 scenarios consider small, medium and large. necessary (have Small based on smallest earthquake that can used on special damage system. projects). San Francisco Varies After completion of the Water System Minor damage, within 3 Unknown, Yes None Pipe segments, fittings and Public Utilities around Improvement Program, the goals are: days, typical break, within depends on other equipment Commission system -Deliver the winter demand (309,234 m3/day) 14 days. Within 30 days for severity of stockpiled at strategic (S.F. City within 24 hours with 90% reliability most major system extents; failure locations throughout the distribution, -Deliver average day demand (431,490 up to 90 days for bridge and system. see * bottom of m3/day) within 30 days with 90% reliability tunnel work, depending on Table 1) earthquake location. Evaluations ongoing based on specific earthquakes on Hayward, Calaveras, and San Andreas faults. San Francisco Varies After completion of the Water System Minor damage, within 3 Unknown, Yes None Pipe segments, fittings and Public Utilities around Improvement Program, the goals are: days, typical break, within depends on other equipment Commission system -Deliver the winter demand (813,775 m3/day) 14 days. Within 30 days for severity of stockpiled at strategic (wholesale, within 24 hours with 90% reliability most major system extents; failure locations throughout the see * bottom of -Deliver average day demand (1,135,500 up to 90 days for bridge and system. Table 1) m3/day) within 30 days with 90% reliability tunnel work, depending on earthquake location. Evaluations ongoing based on specific earthquakes on Hayward, Calaveras, and San Andreas faults. Table 3M - page 2 444 Organization Ground Performance Criteria Restoration Time Estimate Number of Mutual Aid Alternate Forms Earthquake Materials and Failure Employees and of Assistance Equipment Hazard to Restore Assistance System Agreements? Santa Clara High Level of service goal is potable water service -45 to 60 days for M7.9 San Unknown No, but None, but -spare pipe in diameters Valley Water at the average winter flow rate available to a Andreas earthquake. planning to planning to 508 – 3,048 mm District minimum of one turnout per retailer within 7 -30 to 45 days for a M6.7 obtain in near secure retainer -valves and appurtenances days. Southern Hayward future. agreements for -internal pipe joint seals earthquake. contractors to -7 to 10 days for a M6.2 perform Central Calaveras infrastructure earthquake. emergency -earthquakes were modeled repairs based on probability of occurrence Japan Chiba Prefecture Low classified goals for water supply: 28 days 500 Yes None -aluminum canned water - Waterworks (maybe) -3 liters/day/person a within 3 days after Would like to repair water -necessity for camping Bureau earthquake supply facilities within 4 such as tents, blankets, -20 liters/ day/person from 4 days to 10 days weeks, even if Hanshin sleeping bags, mats, after earthquake earthquake grade occurs. -radios -100 liters/ day/person from 11 days to 21 -Not sure if specific for days after earthquake earthquake: stockpile -250 liters/ day/person from 22 days to 28 pipes, bends, cover joints days after earthquake Fukuoka City Low Essential water volume increases according to 4 weeks 19 normal Yes 12 work units None Waterworks the elapsed days following the earthquake. M7.1 on Kego fault. 100 skilled from private Bureau -3 liters per person in 3 days Damages estimated by employees companies, -water supply increases with passing time, dividing City into 250 m can be Fukuoka Pipe until almost fully recovered the water supply meshes, each mesh assigned available Work Company system in 4 weeks. earthquake shock. Association Hachinohe Moderate Aim for ending emergency restoration within 3 weeks 174 Yes None -water service tank Regional Water three weeks M8.2 used to calculate days -bottled water Supply needed for restoration -pipe material (ductile iron Authority pipe) Hanshin Water Moderate Emergency restoration work of damaged 1 week Yes None None Supply facilities will be completed within one week General earthquake, Authority restoration shorter than end suppliers restoration process Kanagawa Water High Goal is to restore supply water to four No estimate 433 Yes None Stockpile materials and Supply waterworks (constituent bodies) within 7 days. equipment for post- Authority earthquake restoration to continue water supply at each 40 water supply point. (e.g., portable generator, measure for chlorine, etc.) Table 3M - page 3 445 Organization Ground Performance Criteria Restoration Time Estimate Number of Mutual Aid Alternate Forms Earthquake Materials and Failure Employees and of Assistance Equipment Hazard to Restore Assistance System Agreements? Kobe Moderate Post-earthquake performance criteria are as 4 weeks 343 Yes None None Waterworks follows. Assume similar level as the See Note 3. Bureau a. Complete emergency restoration within 4 1995 Hanshin-Awaji Great weeks earthquake. b. Step-by-step provision of emergency The 1995 earthquake showed drinking water the tolerable limit for water c. Water distribution toward emergency system outage is hospitals and schools approximately four weeks. d. Deciding emergency restoration area in a See Note 2 for restoration fair order process. e. Stabilization of the people's livelihood Nagoya Moderate -First 3 days provide 3 liters/person/day using 4 weeks targeted, but do not Do not Yes Request Equipment in 24 material Waterworks and mobile and central station water supply to have estimate of how long it know how cooperation warehouses Sewerage sustain life will take to restore system to many staff from retired -1 m3 water tank (mobile Bureau -4 to 10 days provide 20 liters/person/day normal. will be staff type) using mobile and central station water supply available to -1 KVA dynamo for cooking and washing face and hands make -temporary hydrant (4 -11 to 21 provide 100 liters/person/day using repairs taps) central station and pipeline distribution water -1 m3 emergency water supply for washing cloths and bathing supply tank -22 to 28 days provide 250 liters/person/day -polyethylene tank (5, 10, using central station and pipeline distribution and 20 liter) water supply for regular life function. -tent -Increase reliability of pipe distribution system -fire hydrant hose over time until fully restore within 28 days. -Light and tools, -pipe drawings (1/2500) Osaka Municipal High -Within 3 days from earthquake occurrence - 1 month 2,200 Yes Emergency Various emergency Waterworks Securing of drinking water for refugees (3 Restoration estimate based Mutual water supply equipment and materials; Bureau liters /day/person) on calculations of how many assistance agreements with water tank truck, -Within 10 days from earthquake occurrence - teams will perform pipe or agreements the Japan Truck polyethylene bags for Securing of eating and drinking water (20 facilities repairs using 5 with 14 major Association and emergency water supply, liters/day/person) earthquake scenarios. cities. a soft drink temporary water tanks, -Within 15 days from earthquake occurrence - maker. and pipes, etc. Securing of subsistence water (100 liters/day/person) -Within a month from earthquake occurrence- Securing of daily life water (250 liters/day/person) Table 3M - page 4 446 Organization Ground Performance Criteria Restoration Time Estimate Number of Mutual Aid Alternate Forms Earthquake Materials and Failure Employees and of Assistance Equipment Hazard to Restore Assistance System Agreements? Tokyo High -The supply routes to the capital center 30 days 500 Yes Constructor Tokyo Waterworks Metropolitan organizations are restored within three days -M6.9 and M7.3 Tokyo Bay Agreements secures all the restoration Waterworks after the earthquake occurs. Northern part Earthquakes; materials of the supply Bureau -other water supply facilities are restored and M6.9 and M7.3 Tama routes such as the capital within 30 days inland Earthquake. The center organizations, and hypocenter depths were 30- provides to the 50 km, respectively. constructors. -The water suspension rate is calculated for 250 m mesh in consideration of pipe length, material and caliber, liquefaction, and ground speed. Tottori City High After 2-3 days: Emergency water supply by 3 or 4 weeks 30 Yes Assistance using stored water Earthquake JMA seismic agreements with After 4 days: Direct water supply to important intensity 6. cooperative facilities with emergency supply pipelines Estimation by total predicted water works After 21 to 28 days: restore system completely number of pipe damages and association in ability of repair parties. the City. Estimate 1.6-2.4 pipe breakages per km, 250 of transmission and distribution pipes and 700 of supply pipes. Yokahama High See Note 4. After earthquake until third day, 28 days 300 Yes The union of Stockpile materials and Waterworks called the confusion period, Yokahama -Yokahama Waterworks Prepares to pipe equipment at 14 sites in Bureau Waterworks supplies water to residents by the estimates for major accept the construction the city and through underground circulating type water tanks and earthquake based on support from company's mutual assistance stored water in the distribution reservoirs. One earthquake disaster example cities not members repairs agreements. person can use 3 liters/day. After that until that happened in other cities. affected by broken pipes -DIP and service pipe seventh day, called the primary restoration disaster and and will work material, bottled water, period, the residents receive water from between these with employees. portable tank, power emergency water supply taps. One person can cities, carries generator, fuel, emergency use 10 liters/day. After that until fourteenth out disaster water supply tap, battery day, called the secondary restoration period, prevention charger, pump, hand the residents receive water from emergency training twice operation pump, simple water supply distribution stations and a year filter machine, radio temporary water tap. One person uses 20 facilities liters/day. After that, called the revival period, one person uses 100 liters/day. Table 3M - page 5 447 Organization Ground Performance Criteria Restoration Time Estimate Number of Mutual Aid Alternate Forms Earthquake Materials and Failure Employees and of Assistance Equipment Hazard to Restore Assistance System Agreements? Japan Water The Ministry of Health, Labor and Welfare 28 days is in the guideline See Note 6. Works has the standard of water works facilities that for anti-earthquake planning Association Japanese call the performance criteria. Japan of water supply system (Kazutomo Water Works Association published the (draft) that is supervised by Nakamura) design criteria for water works facilities and the Ministry of Health, and the earthquake-resistant design criteria for Labor and Welfare and Japan Water water works facilities that most of Japanese published by the Japan Research Center water works use for designing their facilities. Water Research Center. (Yasuhiko Sato) The restoration goal should be within 4 weeks (28 days) if possible, to decrease fear of sufferer and stabilized their daily life. See Note 5. Table 3M Notes: 1. East Bay Municipal Utility District Service Level Goals Service category Operating Earthquake Maximum Earthquake General -Minimal secondary damage and risk to the public -Minimal secondary damage and risk to the public -Limit extensive damage to system facilities -Limit extensive damage to system facilities -All water introduced into distribution system minimally disinfected, using -All water introduced into distribution system minimally disinfected Orinda and Walnut Creek treatment plants -All water introduced into the distribution system fully treated -All water introduced into the distribution system fully treated Fire Service -Sufficient portable pumps to provide limited fire service in all areas -Sufficient portable pumps to provide limited fire service in all high risk areas -All areas have minimal fire service (one reliable pumping plant and reservoir) -All areas have minimal fire service (one reliable pumping plant and reservoir) -High risk areas have improved fire service (at facilities reliable, minimum fire -High risk areas have improved fire service (at facilities reliable, minimum fire reserves) reserves) -Service to all hydrants within 20 days -Service to all hydrants within 100 days Hospitals and Disaster -Minimum service to all affected areas within 1 day (water available via -Minimum service via distribution system or truck within 3 days Collection Centers backbone distribution system near each facility) -Impaired service to affected area within 3 days (water available via -Minimum service within 10 days (water available via backbone distribution distribution system to each facility, possibly at reduced pressures) system near each facility) Domestic Users -Potable water via distribution system within 1 day -Impaired service within 30 days (water available via distribution system to -Impaired service to affected area within 3 days (water available via each domestic user, possibly at reduced pressures) distribution system to each domestic user, possibly at reduced pressures) -Potable water at central locations for pick up within 3 days -Minimum service to 70% of customers within 10 days Commercial Industrial, -Impaired service to affected area within 3 days (water available via -Potable water at central locations for pick up within 1 week and other Users distribution system to each commercial or industrial user, possibly at reduced -Minimum service to 70% of customers within 10 days pressures) -Impaired service to 90% of customers within 30 days 2. Kobe restoration scenario is as follows: 1st run the water through the pipes to find leakage. This requires restoration to be completed one by one downstream from the transmission tunnels branch connections, even with plenty of human resources. Using multiple sources to the distribution pipe network (such as Large Capacity Transmission Main, Emergency Contact Pipes, and Prefecture Water), in addition to the existing transmission tunnels, we can find the leakage and repair them in several directions at the same time. 2nd isolate a pipe block by shutting valves from others to easily find the leakage in the block. The work force leveling in every stage is concerned with reduction of the restoration period. Kobe Waterworks Bureau is trying to simulate those processes with several assumptions on seismic practices, water sources, new transmission systems, and so on. The population distribution and demographics in Kobe have been floating since the 1995 earthquake, but they have become stable gradually; in consideration of this the recovery period is being re-examined. Table 3M - page 6 448 3. Kobe Waterworks Bureau has mutual aid agreements for disasters in a group of 15 large cities as well as with nearby local cities. Those agreements include both providing emergency drinking water for customers and repairing the damaged water system. Extensive damage predicted for the great offshore earthquake expected in the near future. In such occasion, the neighboring governments also may suffer, and Kobe may not be able to expect aid from them. Therefore, it is very important to have a mutual aid agreement among 15 large cities in Japan. In the case of Kobe City, Osaka City and Hiroshima City are assigned as the mutual aid city. 4. Yokahama Waterworks Bureau performance criteria Time progress 8 hrs 16 hrs 24 hrs 2 – 3 days 4-7 days 8-14 days 15-28 days Distributed drinkable water volume 3 Liters/day/person 3 L/d/p 10 L/d/p 20 L/d/p 100 L/d/p Transportation water supply by vehicle to hospitals XXXXXXXX XXXXX XXXXX XXXXX Transportation water supply by vehicle to refuge places XXXXX XXXXX XXXXX Share water of Distribution Reservoir’s water XXXXXXXXXXXX XXXXX XXXXX XXXXX Share water of Underground Circulation Type Water Tank’s water XXXXXXXXXX XXXXX Distribution water from Emergency Water Supply Tap YYYYY XXXXX XXXXX XXXXXX Distribution water from Temporary Water Supply Pipeline YYYYY XXXXX XXXXXX Distribution water from Water Supply Pipeline YYYYY YYYYY YYYXXX 5. Japan Ministry of Health, Labor and Welfare restoration performance goals published by the Japan Water Research Center: Period Quantity Carry Distance Supply Methods 0-3 days 3 liters/person/day within 1000 m anti-seismic tank, emergency tank, water trucks 10 days 20 liters/person/day within 250 m temporary tap near trunk main 21 days 100 liters/person/day within 100 m temporary tap near lateral main 28 days normal amount as before earthquake within 10 m temporary tap to each house 6. Japan Water Works Association has the report of emergency response for water supply system. Just after the Kobe earthquake, the committee set up and studied the emergency response procedure. The contents of report are: a) basic rule of assistance request b) communication procedure c) about expenditure and accident, etc d) organization of assistance team e) manual for assistance activity f) manual for restoration g) assistance activity in field h) publicity and public relations i) recording of activities j) sample of mutual assistance agreement. Table 3M - page 7 449 450 5th AwwaRF-JWWA Water System Seismic Workshop Survey Request 451 5th AwwaRF-JWWA Water System Seismic Workshop Information Survey 5th AWWARF/JWWA Water System Seismic Workshop August 15-17, 2007 Oakland, California During the discussion session scheduled for Thursday August 16 from 13:30 to 17:00 hours, we would like to focus on the topics of: 4. Post-earthquake water supply in the water distribution network, and 5. Water System post-earthquake performance criteria. These two topics are very closely related. The purpose for selecting these topics is to obtain a better understanding on what water systems are doing to determine: (a) what is an adequate post- earthquake water supply that can be used immediately following an earthquake, (b) how can this water volume be determined, (c) to what level should a water system perform during an earthquake, and (d) other related questions. It is recognized that each water system cannot address these issues in the same manner, but understanding how different water systems address these issues is helpful in improving water system seismic practices. All participating water organizations are requested to prepare in advance of attending the 5th AWWARF/JWWA Workshop in Oakland, California. Please work with the appropriate knowledgeable personnel in your organization to provide information on the topics identified in the following pages. The water supply portion of this survey is oriented toward water distribution networks. If your organization is not in the business of distributing directly to customers (for example your organization may be in the business of wholesale supply to distributing organizations), then some of the information requested regarding water supply may not apply or may require special description to understand how the topic applies to your organization. This survey is not intended to take too much time. There are 18 statements on the following pages requesting information. The requested information is hopefully readily available. Please provide what you can. If appropriate, additional information can be provided at a later time. Please type all responses in English and email responses to [email protected] by Monday August 13, 2007. You can provide additional information to Craig Davis from the Los Angeles Department of Water and Power (in electronic form) on August 15. Please provide information requested on the following pages. If necessary and appropriate please provide additional pages of information (in English) to help others gain an understanding of your water system as related to the requested information. If you do not have adequate information to provide a response or you do not believe an item applies to your organization please indicate so or leave it blank. Please make the units of measurement very clear. See attached for recommended units. Survey-1 452 5th AwwaRF-JWWA Water System Seismic Workshop 1. The area for which you are responsible for distributing water ______(regional description and area in square units) 2. Total population within the distribution service area ______(for wholesale agencies total population of all constituent agency service areas) 3. Total number of service connections ______If possible please provide a breakdown of service connections in the following, or similar, categories: a. Single family dwellings ______b. Multi-family dwellings ______c. Commercial/industrial/government ______d. Agriculture/irrigation ______e. Recreational ______f. Other (please specify) ______ For wholesale agencies provide the number of turnouts ____ 4. Total length of pipe in the distribution network ______If possible, but not necessary, please provide a breakdown of pipe lengths by pipe type: a. Cast iron ______b. Ductile Iron ______c. Steel ______d. Plastic (e.g., PVC) ______e. Other (please specify) ______ 5. The range of pipe diameters within the distribution network (include transmission and distribution pipe) ______ 6. The total storage capacity in the distribution system ______ 7. Number of storage tanks and reservoirs in the distribution system ______ 8. What is the size range of the storage tanks and reservoirs within the distribution system? Smallest storage volume: ______Largest storage volume: ______ 9. Does your organization believe they have enough water stored and available to the local distribution network for use following a damaging earthquake? (mark one) ______yes _____ no _____ do not know If yes or no, how do you know, was a specific evaluation performed (please briefly explain)? ______ Survey-2 453 5th AwwaRF-JWWA Water System Seismic Workshop 10. Please estimate the level of total ground failure hazard within the distribution area (including surface fault rupture, landslide, liquefaction and lateral spreading). ____low _____ moderate ____ high ____ do not know 11. In your distribution area, are there any special provisions for water supply to fight fires after an earthquake? ____ yes ____no If so, what is total supplementary fire water supply volume? ______ Please briefly explain special fire provisions (e.g., cisterns, separate fire fighting water system, etc.; attach information as appropriate): ______ 12. Do you have any special provisions for obtaining additional emergency water supplies following an earthquake? (e.g., inter-connection with neighboring water system) ___ yes ____no Please briefly explain emergency water supply provisions (attach information as appropriate): ______ 13. What plans do you have for providing emergency drinking water for customers who may not have water service following an earthquake (under emergency response conditions)? Please briefly explain any emergency drinking water distribution plans and identify if you maintain special equipment and materials for distribution and/or have contracts in place for assisting (attach information as appropriate): ______ Survey-3 454 5th AwwaRF-JWWA Water System Seismic Workshop 14. Does your organization have any specific post-earthquake performance criteria such as goals at which your system is intended to function following an earthquake? (Examples: (a) provide a minimum level of supply to all pressure zones following an earthquake, (b) return service to 70% of customers within 10 days following a magnitude 7 earthquake, or (c) similar criteria). ___ yes ____no Please briefly explain any water system seismic performance criteria and provide any appropriate supporting information (provide attachments as appropriate): ______ 15. Total number of service employees in your organization who will be available to repair earthquake damage (e.g., broken water pipes) ______ 16. Do you have agreements in place to obtain assistance from others in repairing the damaged water system? ____ yes ____ no a. If yes, are these mutual aid or mutual assistance agreements? _____ yes _____ no b. Do you have other types of available assistance agreements? (e.g., community members, volunteer organizations, etc.)? _____ yes _____ no If so, please provide a brief explanation: ______ 17. Do you have an estimate of how long it will take for your system to return to normal service conditions following an earthquake? ____ yes ____ no If yes, a. Are estimates based on any general earthquake or specific earthquake scenarios? Please provide brief explanation. ______b. How were estimates made? ______ 18. In addition to materials and equipment used for normal operations and maintenance, do you stockpile specific materials and equipment for post-earthquake restoration? ____ yes ____ no If yes, please briefly describe (provide attachments as appropriate): ______ Survey-4 455 5th AwwaRF-JWWA Water System Seismic Workshop Recommended units of measurement: Length: Km, meters, miles, feet Area: hectare, square meters, square miles, square feet Volume: liters, cubic meters, cubic feet, gallons Please clearly specify the units used. Survey-5 456 5th AWWARF/JWWA Water System Seismic Conference TECHNICAL TOUR Walnut Creek Water Treatment Plant, Walnut Creek, CA San Pablo Reservoir Recreation Area, El Sobrante, CA San Francisco Public Utility Commission’s Crossover and Isolation Valves Project, Fremont, CA 457 458 WALNUT CREEK WATER TREATMENT PLANT General Facts Plant Capacity: 160 Million Gallons per Day Commissioned in 1967 with major improvements constructed 2002 to 2005 Systems Facts Raw Water: In-line rapid mix Filters: Six filters - 2,304 square feet each; 6 to 8 gallons/minute/square foot Filter Bottoms: “Wheeler bottom” (4 filters), false floor with nozzle type (2 filters) • Dual Media: Sand (0.55 mm size; 12-inch depth), Anthracite (1.0 mm size; 3-foot depth) Chlorine Contact Chamber: 4 million gallons (MG) spiral design Clearwell: 16 MG Chemical Systems: • Chemicals: ammonia, polyaluminum hydrochloride, cationic, anionic, and nonionic polymers, sodium hypochlorite, sodium hydroxid, fluorosilicic acid • Chemical Storage: Centralized, 30 day minimum capacity • Chemical Feed: Eductor and metering pumps; “powerless” backup feed systems. Reclamation/Solids Handling Systems: All reclaimed water is recirculated back to the head of the plant at ≤ 10% of the plant rate. Solids are off-hauled. 459 460 FISHING EBMUD San Pablo Reservoir is known as one of the SAN PABLO RESERVOIR RECREATION fish finest fisheries in the East Bay. The AREA visitor center offers fishing licenses for sale and a wide array of bait and tackle. THE OAKS RESERVABLE The lake is stocked regularly with trout, GROUP SITE catfish and bass. Our friendly and knowledgeable staff are available to assist A lush, beautiful park setting, you with all your freshwater fishing and perfect for your wedding, boat boating needs. They know the best reception, anniversary, fishing spots and can help you catch the BIG ONE! birthday party or other special event. Rustic, yet private, BOAT RENTALS with lake views, The Oaks offers a spacious area for up to Patio boats, deluxe and motor boats, kayaks and row boats 100 guests, including parking. hike are available for rent ADA accessible. For additional daily. The aluminum information, please contact fishing boats come the recreation area at 510- equipped with a four- 223-1661. stroke motor, which is ideal for fishing and picnic cruising the waters of the reservoir. Rent a boat six times and receive a free 1/2 day 2007 PARK FEES weekday rental. ENTRY/PARKING $6.00 SEASON PASS $75.00* PICNICKING BOAT LAUNCH $4.00/$6.50 (weekends-holidays) SEASON PASS $75.00* The main recreation area and the boat launch offer picnic ENTRY PLUS BOAT LAUNCH ANNUAL PASS $140.00* sites with tables and barbeques. All of the sites have lake kayak DAILY FISHING ACCESS PERMIT $4.00 views. The main recreation area has a children’s playground and CANOE/KAYAK LAUNCH $3.00 SEASON PASS $110.00* lawn area. The visitor center and THE OAKS PICNIC SITE $200.00 SAN PABLO RESERVOIR café are conveniently located. There is also a reservable picnic *50% OFF FOR SENIORS AND THE DISABLED RECREATION AREA site, The Oaks, that can accommodate 100 people. San Pablo Reservoir CLOSE TO NATURE... VISITOR CENTER Recreation Area The visitor center offers a complete 7301 San Pablo Dam Road CLOSE TO HOME array of fishing bait and tackle, as El Sobrante, CA 94803 well as outdoor clothing, hats, Phone: 510-223-1661 sunscreen, gifts, and supplies. If Fax: 510-223-1015 your birthday falls within one week of your visit, you receive a free lunch at the café. Maximum value is For additional information, please visit 461 $6.50. WWW.EBMUD.COM WWW.NORCALFISHING.COM EBMUD TRAILS/HIKING EBMUD WELCOME TO SAN PABLO RESERVOIR San Pablo Recreation Area has a SAN PABLO RESERVOIR RECREATION RECREATION AREA shoreline trail for hiking and fishing AREA access and the Old San Pablo Dam Road trail, which runs from the boat launch, through the main recreation area to Kennedy Grove Regional Park. This trail connects with several other regional trails. KAYAKING/CANOEING San Pablo offers some of the best flat water kayaking and canoeing in the East Bay. Come for the day or San Pablo Reservoir Recreation Area offers a just a few hours. We offer rentals wide variety of exciting outdoor activities, of tandem and single kayaks from including fishing, boating, picnicking, kayaking the marina at the main recreation and hiking. The park also has facilities for group area. Paddle along 14 miles of shoreline and discover sandy beaches, great fishing spots, events, weddings and meetings. The park is and spectacular wildlife viewing. open to the public mid-February through the end of October. BOAT LAUNCH San Pablo offers an eight lane boat launch facility that can PARK HOURS accommodate motor boats and kayaks/canoe launching. Plenty of parking is available and bait and tackle are FEBRUARY 6:30AM — 5:00PM available on the weekends. MARCH 6:00AM — 5:30PM WILDLIFE VIEWING APRIL 6:00AM— 6:00PM(PST) Bird watching opportunities feature flocks of white pelicans, migratory water fowl such as 6:00AM— 7:00PM(DST) geese, ducks, and shorebirds. Along the trails within the park, a viewer can see a MAY 6:00AM — 7:30PM variety of upland game species, including wild turkey, quail and dove, and an array of JUNE 6:00AM — 8:00PM predators such as eagles, ospreys, hawks, and owls. Also be on the lookout for deer and bobcats. JULY 6:00AM — 8:00PM THE CAFE San Pablo is an EBMUD AUGUST 6:00AM — 7:30PM drinking water reservoir, The San Pablo Café offers premium coffee, swimming and wading are espresso, snacks, and sandwiches on SEPTEMBER 6:30AM — 7:00PM prohibited. weekdays. On weekends, the full service grill OCTOBER 6:30AM — 6:00PM is open for breakfast and lunch. We offer a For additional Rules and visitor’s pass (no gate fee) that is valid for up Regulations, please inquire at 462 to one hour. Validation required. the Visitor Center. Seismic Upgrade Project Update Background In coordination with the California Division of Safety of Dams (DSOD), EBMUD commissioned a study to determine the seismic safety of San Pablo Dam. The study was completed in October 2004. It showed that some of the soils and foundation that make up the dam are susceptible to liquefaction. If a maximum credible 7.5 earthquake occurred on the Hayward Fault, the study predicted the dam would slump and decrease in height, allowing water to flow over the top, causing flooding downstream. Based on the study’s recommendations, EBMUD lowered the water level behind the dam to protect downstream communities from flooding in case of earthquake damage. EBMUD explored various alternatives for the permanent retrofit of the dam and is now designing an expansion of the downstream buttress for the dam. During construction, the reservoir will remain in service at its currently reduced water level. Details about the project are How will EBMUD permanently improve the available at www.ebmud.com embankment? EBMUD will mix concrete deep into the soil on the dry side below the dam, which will strengthen the foundation. EBMUD will then rebuild the buttress making it higher and wider. Here is the type of equipment that will be used to reinforce the dam’s foundation. 463 View of San Pablo Dam from Kennedy Grove Sea Foam Trail Vista Point Visual simulation of proposed San Pablo Dam with the downstream buttress looking southwest as it looks before construction. in place. What will it look like? How long will the construction take? The contours of the dam will change due to the larger The San Pablo Dam Seismic Upgrade will take buttress. A visual simulation is shown in the photos above. approximately two years to construct and is expected to begin in early 2008. How will this affect recreation at Kennedy Grove and San Pablo Reservoir? How to get more information? There will be some noise, visual, and access impacts. The Draft EIR and the Response to Comments in the EBMUD will mitigate the temporary impacts to the degree Final EIR are available for review or download at possible. Additional information can be found at www.ebmud.com. These documents include all the known www.ebmud.com, see Current Events/ProjectUpdates. impacts associated with this project and the measures that The majority of visits and events at Kennedy Grove are will be used to mitigate the impacts. on weekends. EBMUD will allow access to Kennedy How much will it cost? Grove via San Pablo Dam Road on weekends and for selected special events. Weekday access to the Grove will The estimated cost of construction is $60 million, and it is be via Hillside Drive. EBMUD is working closely with the funded under EBMUD’s existing capital improvement East Bay Regional Park District to develop a traffic budget and rate structure. control and community outreach plan to minimize impacts Schedule Information to the residents on Hillside Drive and Patra Drive. • The Final Environmental Impact Report approved by Recreation facilities at San Pablo Reservoir will not be EBMUD’s Board of Directors September 26, 2006 adversely affected. • Design began September 2006 Design Testing - April through May 2007 Environmental monitoring - April 2007 through end of project Do you have questions, concerns? • A pre-construction public meeting is planned at Would you like to be added to a mailing list for Kennedy Grove in October 2007. future notices? Call (510) 287-2053 • Construction is expected to begin in January 2008 Email [email protected] • Construction is expected to be completed in 2010 or go to www.ebmud.com 464 April 2007, SPDSU, MB Bay Division Pipelines #3 & #4 Crossover and Isolation Valves at Hayward Fault Crossing Project The Crossover and Isolation Valves Project is a 15-month, $20million project located in Fremont, California. It is part of the San Francisco Public Utilities Commission's (SFPUC) $4.3billion Water System Improvement Program (WSIP) to repair, replace, and seismically upgrade the Hetch Hetchy System's aging pipelines, tunnels, dams, and reservoirs. The SFPUC has four main transmission/distribution pipelines in the Bay Area. Bay Division Pipelines #3 and #4, which were built in the 1950's and 1960's, are a 2m diameter reinforced concrete pipe and a 2.44m diameter pre-stressed concrete cylinder pipe, respectively, and carry a combined to total of up to 829ML/day at 865kPa. This project is intended to protect neighbors and their property, prevent flooding of a major inter- state freeway, and ensure a reliable water supply to Bay Area residents by allowing the SFPUC to isolate a rupture at the seismically active Hayward Fault. Situated within 0.5km on each side of the fault, the two valve vaults each contain new 2m welded steel pipe and butterfly valves, and a 1.07m crossover. The main valves will be operated by hydraulic actuators, remotely operated and monitored. Substantial completion is anticipated at the end of October 2007. The SFPUC owns and manages the Hetch Hetchy water system that delivers drinking water from the Sierra Nevada Mountains to 2.4million customers in four Bay Area counties. The SFPUC also treats the wastewater for the City of San Francisco and generates clean hydropower that provides electricity for San Francisco municipal services. For more information, visit www.sfwater.org. 465 466