Innovative Dam and Levee Design and Construction for Sustainable Water Management

United States Society on Dams

Innovative Dam and Levee Design and Construction for Sustainable Water Management

32nd Annual USSD Conference New Orleans, Louisiana, April 23-27, 2012 CONTENTS

Plenary Session

Call to Stewardship ...... 1 Patrick J. Regan, Federal Energy Regulatory Commission

Dams and Energy Sectors Interdependency Study ...... 3 William N. Bryan and Kenneth Friedman, U.S. Department of Energy; Tiffany Choi, SAIC; Enrique E. Matheu, U.S. Department of Homeland Security; Laura P. Keith, SRA International; Elizabeth Hocking, Argonne National Laboratory; and Bill H. Clark, SRA International

An Overview and Comparison of Navigable Storm Surge Barriers...... 5 P.T.M. Dircke, ARCADIS The Netherlands; T.H.G. Jongeling, Deltares; and P.L.M. Jansen, Rijkswaterstaat Centre for Infrastructure

Organizational Response to Failure...... 7 Christopher J. Hill, Metropolitan Water District of Southern California

Risk Analysis Guides — Dam Safety Decisions for Beaver Park Dam, Colorado ....9 John W. France, URS Corporation; and Bill McCormick and Matt Gavin, Colorado Division of Water Resources

Changes to Reclamation’s Dam Safety Review Process ...... 11 Daniel W. Osmun, William O. Engemoen and William R. Fiedler, Bureau of Reclamation

The Taum Sauk Dam Failure Was Preventable — How Do We Prevent the Next Operational Dam Failure? ...... 13 David W. Lord, Federal Energy Regulatory Commission

A Dam Incident at Table Rock Lake Dam ...... 15 D. Wade Anderson, Elmo J. Webb and Bobby Van Cleave, Corps of Engineers

Lower Dam Rehabilitation — From FERC to DCR ...... 17 Greg Zamensky, Black & Veatch Corporation; and Mishelle Noble-Blair and Greg Prelewicz, Fairfax Water

Consequence Estimation Dam Failures ...... 19 William Lehman and Jason Needham, Corps of Engineers

Dam and Levee Safety Risk Assessment — Evaluation Routing and Life Loss Estimation Using LIFESIM ...... 21 Woodrow Fields, Corps of Engineers; Chris Bahner, WEST Consultants, Inc.; Jason Needham, Corps of Engineers; and Christopher R. Goodell, WEST Consultants, Inc.

v Modeling Adaptive Threats: Incorporating a Terrorist Decision Model into Security Risk Assessments ...... 23 Yev Kirpichevsky, Institute for Defense Analyses; Enrique E. Matheu, U.S. Department of Homeland Security; and Yazmin Seda-Sanabria, Corps of Engineers

SONAR for Protection of Maritime Structures ...... 25 Jason Curd, L. Sebastian Bryson and Michael Kalinski, University of Kentucky

Defensive Directed Energy Systems for Dam Security...... 27 Alexander D. Krumenacher, L. Sebastian Bryson and Michael E. Kalinski, University of Kentucky

Quantitative Risk Analysis for a Dam Under Construction in Spain ...... 29 Daniel Sanz-Jiménez, Confederación Hidrográfica del Duero; Ignacio Escuder-Bueno, Universidad Politécnica de Valencia; and Francisco Silva-Tulla, Consultant

Concrete Dams

Recent Experience with Alkali Aggregate Reaction Effects in Concrete Dams .....31 Dan D. Curtis, HATCH Renewable Power

Addressing AAR Stability Concerns at Santeetlah Dam ...... 33 Jesse Kropelnicki, PB Americas, Inc.; Michael Sabad, Alcoa Power Generating Inc.; and Paul F. Shiers and Edith J. Butterworth, PB Americas, Inc.

Freeze-Thaw Deterioration on Aging Structures — Structural Analysis of Gerber Dam ...... 35 Hillery Venturini, Bureau of Reclamation

Spillway Chute Slab Concrete Delamination and Spalling Due to Thermal Expansion...... 37 Daniel D. Mares, Bureau of Reclamation

Concrete Thermal Strain, Shrinkage and Cracking Analysis for the Panama Canal Third Set of Locks Project ...... 39 Vik Iso-Ahola, Bashar Sudah and Vincent Zipparro, MWH Americas, Inc.

Hydromechanical Analysis for the Safety Assessment of a Gravity Dam ...... 41 Maria Luísa Braga Farinha, Eduardo M. Bretas and José V. Lemos, Portuguese National Laboratory for Civil Engineering

vi Monitoring

Automatic Data Acquisition System at Santeetlah Dam ...... 43 Kevin Finn, PB Americas, Inc.; Alvin Diamond and Michael Sabad, Alcoa Power Generating Inc.; and Paul Shiers and Jesse Kropelnicki, PB Americas, Inc.

Investigation and Evaluation of Seepage Conditions and Potential Failure Modes Around Outlet Conduits ...... 45 Keith A. Ferguson, HDR Engineering, Inc.

Self Monitoring Levees: How Close Are We? ...... 47 Dennis M. Kamber, ARCADIS; Harry R. Kolar, IBM Research; and Rob Vining, HNTB

Developing Embankment Dam Fragilities for Emergency Modeling and Response ..49 Yogesh Prashar, Atta B. Yiadom and Elizabeth Bialek, East Bay Municipal Utility District

Application of Acoustic Imaging for Underwater Substructure Inspection and Mapping ...... 51 Kenneth J. LaBry, Fenstermaker

Improved Characterization of Dams, Reservoirs, Levees and Other Water-Related Infrastructure Through Detailed Multi-Sensor Surveying ...... 53 Todd Mitchell, Fugro Consultants, Inc.

3D Topographic Integration Method on Interior and Exterior Floodplains of Levees Using LiDAR and SONAR Data ...... 55 Myung Hee Jo, Kyungil University; Hyen Cheol Park, Jun Ho Song and Yun Jae Choung, Institute of Spatial Information Technology Research

Embankment Dams

Discussion of Modeling for Analyses of Fully Softened Levees ...... 57 Danny K. McCook, McCook Geotechnical Engineering, PLLC

Utilizing Geophysics in Auxiliary Spillway Integrity Evaluation ...... 59 Cari R. Beenenga, Gannett Fleming, Inc.; L. Andrew Deichert and Joseph M. Seybert, Natural Resources Conservation Service; and David M. Snyder, Gannett Fleming, Inc.

A Large Scale Resonant Column Testing System for Evaluating Dynamic Properties of Gravelly Fill Materials of Dams...... 61 Nam-Ryong Kim, Dong-Hoon Shin, Ik-Soo Ha and Min-Seub Kim, Korea Water Resources Corporation

vii Ragged Mountain Dam — The Twists and Turns of Selecting and Designing a New Dam ...... 63 Randall P. Bass, Schnabel Engineering, Inc.; and Jennifer A. Whitaker, Douglas J. March and Thomas Frederick, Rivanna Water & Sewer Authority

Seepage Control and Monitoring at Two Existing Colorado Earthen Embankment Dams ...... 65 Doug Yadon, AECOM Technical Services, Inc.; and Ron Sanchez, Andy Funchess, Pat Schmidt and Dave Mason, Colorado Springs Utilities

Risk Informed Decision Making Influences on the Ashton Dam Remediation Project Design ...... 67 Roger L. Raeburn, PacifiCorp Energy; Jennifer L. Williams, URS Corporation; and Frank L. Blackett, Federal Energy Regulatory Commission

Case Study: Blakely Mountain Dam ...... 69 Ben Emery, Corps of Engineers

Evaluation on Phreatic Line in Homogeneous Earth Dams with Different Drainage Systems ...... 71 R. Ziaie Moayed, V. Rashidian and E. Izadi, Imam Khomeini International University

Levees

Seabrook Sector Gate Complex — Geotechnical Considerations and Issues ...... 73 Robert Chamlee, ARCADIS

Levee Cutoff Wall Design and Construction through Loose Sacramento River Silts ..75 Jonathan W. Pease and Christopher R. Nardi, Kleinfelder, Inc.

It Is Seepage Indeed — A Sensitivity Study on Seepage and Seepage Induced Slope Stability for Levees ...... 77 Khaled Chowdhury, Richard Millet, Sujan Punyamurthula, Gyeong-Taek Hong and Nichole Tollefson, URS Corporation

Reaching Settlements: Using Design Mediation to Resolve Subsurface Conflict Between Flexible and Rigid Foundations Within Levee System Transition Zones ...79 Michael S. Quinn, ARCADIS; James J. Hance, Eustis Engineering Services, LLC; Richard J. Varuso, Corps of Engineers; and Sean G. Walsh, ARCADIS

Pile Foundation Design in Soft Soil for the World's Largest Drainage Pumping Station ...... 81 Kevin Zitzow, ARCADIS

viii Full-Scale Testing of Levee Resiliency During Wave Overtopping ...... 83 Christopher Thornton, Bryan Scholl, Steven Hughes and Steven Abt, Colorado State University

Flood Protection for the Henderson Bayou Watershed ...... 85 Stephen L. Whiteside, Nabil S. Mikhail and Richard L. Hoffer, CDM Smith

We Do Not Want that to Happen at Our Wastewater Treatment Plant Levee! .....87 Tyler C. Dunn, Stephen L. Whiteside and Michael P. Smith, CDM Smith

Geophysical Investigations for Levee Systems — Killing Several Birds with One Stone...... 89 Michael K. Sotak, Douglas E. Layman and Thomas A. Chapel, Tetra Tech, Inc.

Suction and Movement Monitoring of Levees ...... 91 Vishal Dantal, Charles Aubeny and Robert L. Lytton, Texas A&M University

Enhancing Erosion Resistance of Levee by Ground Modification ...... 93 James T. Kidd, Air Force Research Laboratory; Chung R. Song and Alexander H.-D. Cheng, University of Mississippi; and Wongil Jang, Korea Land and Housing Corporation

Protecting Our National Heritage — The Washington, DC, Levee ...... 95 Pete Nix and Steven Riedy, Tetra Tech, Inc.

Building a Levee in the Alaska Wilderness: Balancing Risk, Robustness, and Project Cost ...... 97 Matthew Redington and Glen Krogman, HDR Engineering, Inc.

Addressing Deficiencies in the Ventura River Levee System...... 99 Ike Pace and Michael E. Zeller, Tetra Tech, Inc.

Sustainable Design for the Soldier Creek Levee Repair ...... 101 John Ruhl, Black & Veatch Corporation; and Seth Laliberty, Corps of Engineers Decomissioning

USSD Guidelines for Dam Decommissioning Projects, Executive Summary .....103 Timothy J. Randle and Thomas E. Hepler, Bureau of Reclamation

Elwha River Restoration: Sediment Management ...... 105 Timothy J. Randle and Jennifer A. Bountry, Bureau of Reclamation

Detailed Plan for Potential Removal of Klamath River Hydroelectric Facilities ...107 Thomas Hepler and Blair Greimann, Bureau of Reclamation

Modeling Channel Formation on the Klamath River Due to Reservoir Drawdown . . 109 Yong G. Lai and Blair P. Greimann, Bureau of Reclamation

ix Environment

Preserving Regulated Rivers by Optimizing Hydroelectric Dam Operations .....111 Brent Travis, WEST Consultants, Inc.

Reservoir Operations for Trout Survival Along the White River ...... 113 Kevin Fagot, WEST Consultants, Inc.; and Mike Biggs, Corps of Engineers

Delivering the Abberton Scheme, An Enhanced Water Resource for South-East England ...... 115 Jonathan Troke, MWH; Jim Jenkins, Essex & Suffolk Water; and Ian Carter and David Knott, MWH

Louisiana DOTD Reservoir Priority Development Program...... 117 William F. McHie and William R. Swanson, MWH Americas, Inc.; and Zahir Bolourchi, Louisiana Department of Transportation and Development

Scripting of Rules in HEC-Ressim for the ACF and ACT Basins...... 119 Kevin Fagot, WEST Consultants, Inc.; Andy Ashley, James Hathorn, Jr., and Joan Klipsch, Corps of Engineers; and Henry Hu and Dan Eggers, WEST Consultants, Inc.

Sustainability of Historic Water Resource Projects Affecting the National Park System ...... 121 Charles Karpowicz, Safety of Dams Engineer

Assessment of the Flood Vulnerability of Dams Due to Climate Change in South Korea ...... 123 Soo Jun Kim, Columbia University; Hung Soo Kim, Jong So Lee and Hui Seong Noh, Inha University; and Kyung Seok Kang, Pyunghwa Engineering Consultants Ltd

Construction and Rehabilitation

Roanoke Rapids Dam — Addressing Concrete Deterioration Issues...... 125 Matthew Pauvlinch, Brayman Construction Corporation

Rock Stabilization to Facilitate Repair of the Historic Ocoee No. 2 Hydro-Electric Project...... 127 Lindsay Cooper, ARCADIS

The Third Time’s a Charm ...... 129 Victor M. Vasquez, M. Leslie Boyd and John L. Rutledge, Freese and Nichols, Inc.; Martin J. Cristofaro, AECOM; Donald A. Bruce, Geosystems, L.P.; and Patrick Carr, Judy Company, Inc.

x Design of Emergency Water Supply Line Tunnel at Warm Springs Dam ...... 131 Sam Yao, Ben C. Gerwick, Inc.; and Hugh Caspe and Michael O’Hagan, HNTB Corporation, Inc.

San Vicente Dam Raise Project — Tensile Strength Testing on Existing Dam and Trial Placement ...... 133 Michel Jubran, MWH; Jim Zhou, San Diego County Water Authority; Russ Grant, Kleinfelder, Inc.; James Stiady,G2D Resources, LLC; and Andrew Oleksyn, San Diego County Water Authority

Partial Demolition and Surface Preparation of Existing San Vicente Dam ...... 135 Eric Sturtz, Black & Veatch Corporation; Nick Patch, Barnard Construction Company, Inc.; Wayne Younger, American Hydro Corporation; and Jerry E. Reed III and Gary Olvera, San Diego County Water Authority

The Beneficial Behavioral Characteristics of Fly Ash-Rich RCC Illustrated through Changuinola 1 Arch/Gravity Dam ...... 137 Quentin Shaw, ARQ (PTY) Ltd.

Construction of a 100-Foot Deep Cofferdam in the Ohio River ...... 139 W. James Marold, MWH

Temporary and Permanent Dewatering of Earth Embankment Dams to Facilitate Rehabilitation ...... 141 Greg M. Landry, Moretrench American Corporation; and Cari R. Beenenga, Gannett Fleming, Inc.

Effective Modeling of Dam-Reservoir Interaction Effects Using Acoustic Finite Elements...... 143 Matthew Muto and Nicolas von Gersdorff, Southern California Edison Company; Zee Duron, Harvey Mudd College; and Mike Knarr, Southern California Edison Company

USACE Emsworth Dam Spillway Gates Rehabilitation ...... 145 Michael Hanley, Electro Hydraulic Machinery Company

Levee Construction and Remediation Using Roller Compacted Concrete and Soil Cement ...... 147 Carl M. Rizzo, Charles W. Weatherford and Paul C. Rizzo, Paul C. Rizzo Associates, Inc.; and John Bowen, ASI Constructors

Mangla Dam Raising — Pakistan ...... 149 J. Dominic Molyneux and Michael Hieatt, Black & Veatch Corporation

Large-Scale Concrete Testing ...... 151 Stephen B. Tatro and James K. Hinds, Tatro Hinds Advanced Concrete Engineering

xi Hydraulics and Hydrology

Inspection of Trunnion Rods at Greenup Dam ...... 153 Mark A. Cesare and J. Darrin Holt, FDH Engineering, Inc.

Improving Debris Management at Lake Lynn Dam ...... 155 Stefan Schadinger and Bryce Mochrie, PB Power; and Andrew Datsko and Jacob Vozel, First Energy

Comprehensive Spillway Tainter Gate Assessment and Identification of Interim Risk Reduction Measures ...... 157 Laurie Ebner and Matt Craig, Corps of Engineers

Maintenance and Repair of Spillway Gates ...... 159 Todd Schellhase, Black & Veatch Corporation

Computational Modelling of Advanced Flow Characteristics in Aerated High Energy Spillways ...... 161 Kevin Franke and Piroz Zamankhan, University of Iceland

Potential Applications for Piano Key Weirs at Dams in the United States...... 163 Greg Paxson, Schnabel Engineering; Blake P. Tullis, Utah State University; and Dave Campbell, Schnabel Engineering

Revisiting Spillway Discharge Coefficients for Several Weir Shapes ...... 165 William Kortney Brown and Gregory S. Paxson, Schnabel Engineering; and Bruce Savage, Idaho State University

Using the Sacramento Soil Moisture Accounting Model to Improve Flood Frequency Estimates for Dam Safety ...... 167 Frank Dworak, Bureau of Reclamation

Site-Specific PMP for North Texas: Bringing HMR 51 into the 21st Century .....169 Bill Kappel and Ed Tomlinson, Applied Weather Associates LLC; Courtney Jalbert and Louie Verrealt, Tarrant Regional Water District

Improving Hydrologic Analysis and Applications Using Quality Weather Radar Data and the Storm Precipitation Analysis System ...... 171 Ed M. Tomlinson, Applied Weather Associates, LLC; Tye W. Parzybok, Metstat, Inc.; Bill D. Kappel and Doug M. Hultstrand, Applied Weather Associates, LLC; and Beth Clarke, Weather Decision Technologies, Inc.

Dam Breach Modeling with Unsteady HEC-RAS: Common Techniques and Assumptions Compared ...... 173 Sunit Deo and Scott M. Muchard, HDR Engineering, Inc.

xii Development and Implementation of Web-Based Dam-Break Flood Inundation Analysis Capabilities ...... 175 Mustafa S. Altinakar, University of Mississippi, Enrique E. Matheu, U.S. Department of Homeland Security; Marcus Z. McGrath and Vijay P. Ramalingam, University of Mississippi; and Jun Z. Zou, U.S. Department of Homeland Security

Dam-Break Flood Inundation Analysis for Lake Youngs Reservoir ...... 177 Henry Hu and John Howard, WEST Consultants, Inc.; and Daniel Huang, Seattle Public Utilities

Dam Breach Analysis Simulation on the Lower Susquehanna River ...... 179 Jay Greska, Bryce Mochrie, Chii-Ell Tsai and Christopher Godwin, PB Power

Wave Overtopping Hydraulic Parameters on Protected-Side Slopes ...... 181 Steven Hughes, Bryan Scholl and Christopher Thornton, Colorado State University

New Reservoir Models for Oklahoma...... 183 John Ruhl, Black & Veatch Corporation; and B. Dan Hernandez, Corps of Engineers

Earthquakes

Analysis of Dam Response Under Foundation Faulting ...... 185 Lelio Mejia and Ethan Dawson, URS Corporation

Considerations for Deformation Analyses for Subduction Zone Earthquake Loadings...... 187 Bryan M. Scott and Navead C. Jensen, Bureau of Reclamation

Shaken, But Not Stirred — Earthquake Performance of Concrete Dams ...... 189 Larry K. Nuss, Bureau of Reclamation (retired); Norihisa Matsumoto, Japan Dam Engineering Center; and Kenneth D. Hansen, Consulting Engineer

Hume Dam — Seismic Analysis of Soil/Structure Interaction ...... 191 Guy Lund, Brad Dawson and Mark Foster, URS Corporation

General Approach Used for the Seismic Remediation of Perris Dam ...... 193 Steven Friesen and Ariya Balakrishnan, California Department of Water Resources

Evaluation for Fundamental Periods of Korean Rockfill Dams with Micro- Earthquake Records...... 195 Ik-Soo Ha, Kyungnam University; and Dong-Hoon Shin and Jeong-Yeul Lim, Korea Water Resources Corporation

xiii Effect of Earthquake on Embankment Dams ...... 197 Gopi Siddappa, P.E.S. College of Engineering

Foundations

Quality Control and Quality Assurance in Cut-off Walls...... 199 D.A. Bruce, Geosystems, L.P.; and G. Filz, Virginia Polytechnic Institute and State University

New Developments and Important Considerations for Standard Penetration Testing for Liquefaction Evaluations ...... 201 Jeffrey A. Farrar, Bureau of Reclamation

Installation of Concrete Cut-Off Walls by Hydrocutters — A Safe and Economical Approach for a Durable Solution ...... 203 Peter E. Banzhaf, Bauer Spezialtiefbau GmbH; Martin Hoegg, Bauer Foundation Corp.; and Philip J. Snyder, GEI Consultants, Inc.

A New Zoned Embankment Dam and Cutoff Wall in Piedmont Geology...... 205 Dennis Hogan and Greg Zamensky, Black & Veatch Corporation

Construction of a Cut-Off Wall for Existing Tailings in Warm Permafrost in Alaska ...... 207 Franz-Werner Gerressen, BAUER Maschinen; and Brian W. Wilson, Golder Construction Inc.

Mitigating Risk When Drilling at the Toe of a Dam ...... 209 Cari Beenenga and Edward J. Barben, Gannett Fleming, Inc.

Pine Creek Dam — Phase IV Void Investigation and Backfilling ...... 211 Kathryn A. White and D. Wade Anderson, Corps of Engineers

xiv CALL TO STEWARDSHIP

Patrick J. Regan, P.E.1

ABSTRACT

Water is power. The power to make the desert bloom. The power to create civilizations. The power to move products to distant markets. The power to industrialize economies. The power to create life. The power to destroy life.

We; dam owners, consultants, and regulators, are the current stewards of a large segment of the world’s water resource infrastructure. Stewardship is defined by the Merriam- Webster dictionary as:

The conducting, supervising, or managing of something; especially: the careful and responsible management of something entrusted to one's care.2

We are entrusted with the current responsibility for the operation of facilities that harness the power of water and make it available to provide varied benefits to society: domestic, industrial and agricultural water, flood control, hydroelectric power, navigation, recreational opportunities, and environmental enhancement. These same facilities also have a cost: monetary, risk of loss of life and property, displacement of populations and environmental degradation.

This paper explores the author’s thoughts on what it means to be a steward of water resource infrastructure.

1 Principal Engineer – Risk-Informed Decision-Making, Federal Energy Regulatory Commission, Division of Dam Safety and Inspections, 503-552-2741, [email protected] 2 Merriam Webster (2011) The opinions expressed herein are those of the author and do not necessarily represent the views of the Federal Energy Regulatory Commission or the Commission’s Division of Dam Safety and Inspections.

1 NOTES

2 DAMS AND ENERGY SECTORS INTERDEPENDENCY STUDY

William N. Bryan3 Kenneth Friedman, PhD4 Tiffany Choi5 Enrique E. Matheu, PhD6 Laura P. Keith7 Elizabeth Hocking8 Bill H. Clark9

ABSTRACT

The U.S. Department of Energy (DOE) and the U.S. Department of Homeland Security (DHS) collaborated to examine the interdependencies between two critical infrastructure sectors – Dams and Energy.10 The study highlights the importance of hydropower generation to the national economy and electric reliability, with a particular emphasis on the variability of weather patterns and competing demands for water which determine the water available for hydropower production. This joint effort underlines the value of a cross-sector partnership model to discuss the challenges and concerns that constitute priority issues for dam and utility owners and operators. Discussions with owners and operators revealed that the storage capacity and conveyance flexibility of most conventional hydroelectric facilities were designed to accommodate local or regional historical patterns of hydrologic variability. Thus, episodic low water conditions, as opposed to long-term drought conditions, are not critical contributors to reduced hydropower production; however, the requirements for providing sufficient water for irrigation, environmental protection, transportation, as well as community and industrial uses are already in conflict in certain places. Low water conditions (e.g., drought) and high water conditions (e.g., flood) resulting from extreme weather variability can strain the operation of dams and heighten the degree of competition for available water. The collaborative process in which this paper was developed provided a unique forum that strengthened partnerships and allowed secure and open information sharing which are key elements to enhancing critical infrastructure resilience.

3 Deputy Assistant Secretary, Office of Electricity Delivery and Energy Reliability, U.S. Department of Energy, Washington, DC 20585, [email protected] 4 Senior Policy Advisor, Office of Electricity Delivery and Energy Reliability, U.S. Department of Energy, Washington, DC 20585, [email protected] 5 Senior Associate, ICF International, Fairfax, VA 22031, [email protected] 6 Chief, Dams Sector Branch, Office of Infrastructure Protection, National Protection and Programs Directorate, U.S. Department of Homeland Security, Washington, DC 20598. 7 Program Analyst, Intelligence, Homeland Security and Special Operations Group, SRA International, Arlington, VA 22202. 8 Policy Analyst, Argonne National Laboratory, Washington, DC 20003. 9 Program Analyst, Intelligence, Homeland Security and Special Operations Group, SRA International, Arlington, VA 22202. 10 The term “critical infrastructure” has the meaning given to that term in section 1016(e) of the USA PATRIOT Act of 2001. Also see the National Infrastructure Protection Plan, U.S. Department of Homeland Security, http://www.dhs.gov/xlibrary/assets/NIPP_Plan.pdf (accessed December 22, 2010).

3 NOTES

4 AN OVERVIEW AND COMPARISON OF NAVIGABLE STORM SURGE BARRIERS

P.T.M. Dircke11 12 T.H.G. Jongeling13 P.L.M. Jansen14

ABSTRACT

Storm surge barriers can greatly enhance protection for coastal cities and ports. An advantage of some barrier types for port areas is that they allow free navigation under normal conditions when they are open. Experience thus far with developing and implementing barrier designs learns there is not one single perfect gate type, and often a tailor made design procedure that selects or combines the most favorable aspects of different gates and other flood protection measures, should be considered in order to find the best fitting solution.

Although barriers can be a suitable solution for flood protection, for sustainable, economically and environmentally reasons they should always be compared to or combined with other flood protection or risk reducing alternatives including flood walls, dikes or natural coastal systems like dunes, or non-structural measures like building codes for adaptive housing in flood zones. Therefore a holistic selection and design approach and integrated solutions are recommended.

This paper presents a systematic overview, comparison and selection of navigable storm surge barriers that are suitable for coastal cities. The gates presented are proven concepts and most designs operate successfully within flood protection systems. The gate types are compared and an overview of advantages and disadvantages for each gate type is given as well as a procedure to select the right gate type for a certain situation. Different aspects including type of gate structures, design criteria, risk management, environmental aspects, navigation aspects, technical design details and operation and maintenance aspects are considered.

11 ARCADIS The Netherlands, Water Division, P.O. Box 4205, Rotterdam 3006 AE, the Netherlands; PH 31(0)10 253 2222; e-mail: [email protected] 12 Rotterdam University of Applied Sciences, RDM Sustainable Solutions, Directiekade 23, Rotterdam 3089 JA, the Netherlands; PH 31(0)10 794 4853; e-mail: [email protected] 13 Deltares, Department of Hydraulic Engineering, P.O. Box 177, Delft 2600MH, The Netherlands; PH 31 (0)88 335 8273; e-mail: [email protected] 14 Rijkswaterstaat Centre for Infrastructure, Ministry of Transport, Public Works and Water Management, P.O. Box 20000, Utrecht 3502 LA, the Netherlands; PH 31 (0)6 11 62 89 39; e-mail:[email protected]

5 NOTES

6 ORGANIZATIONAL RESPONSE TO FAILURE

Christopher J. Hill15

ABSTRACT

Very few dams fail, but when they do, they send shock waves throughout the affected communities. The profession works to avoid a repeat occurrence through understanding technical aspects of the failure and preventing similar occurrences in the future, the media jump to conclusions about the cause of the failure, and the public responds with anger and grief.

Is there anything we can learn about what happens to organizations that experience failure that would also help us prevent repeat incidents?

Studying organizational responses to famous dam and non-dam failures such as Teton Dam, Taum Sauk, the Challenger explosion and others, we can learn a great deal from what an institution does in the wake of a disaster. How can we build an organizational culture that develops values that result in safe dams?

15Team Manager, Safety of Dams Team, Metropolitan Water District of Southern California. 213-217- 7969, [email protected]

7 NOTES

8 RISK ANALYSIS GUIDES — DAM SAFETY DECISIONS FOR BEAVER PARK DAM, COLORADO

John W. France, PE16 Bill McCormick, PE, PG17 Matt Gavin, PE18

ABSTRACT

Beaver Park Dam, originally constructed between 1912 and 1914 has a long history of seepage through the left abutment. In the spring of 2010, a sinkhole was observed on the downstream left abutment, near the dam, in a location of prior seepage concerns. After an initial evaluation, the Colorado State Engineer’s Office (SEO) restricted storage in the reservoir to 20 feet below the spillway crest. A facilitated, expert elicitation, risk analysis was conducted to estimate failure probabilities and risks for 1) the existing facility under normal operation, 2) the existing facility under the currently restricted operation, and 3) a potentially repaired facility under normal operations. The results of the risk analysis were compared to the risk guidelines being used by the Department of Interior, Bureau of Reclamation at that time (2010). The results indicated risks for case 1 that exceeded the guidelines for expedited risk reduction action; risks for case 2 that justified long term risk reduction actions; and risks for case 3 that were generally within the guidelines for decreasing justification for risk reduction action. These results helped the owner in understanding the significance of the existing conditions, the risk reduction benefits resulting from the current restriction, and the need to pursue dam safety modifications for the facility. The results also helped provide the Colorado SEO with a sound basis for the magnitude of the interim reservoir restriction.

16 URS Corporation, 8181 East Tufts Avenue, Denver, CO 80237, [email protected] 17 Colorado Division of Water Resources, 7405 South Highway 50, Salida, CO 81201, [email protected] 18 Colorado Division of Water Resources, 160 Rockpoint Drive, Suite E, Durango, CO 81301, [email protected]

9 NOTES

10 CHANGES TO RECLAMATION’S DAM SAFETY REVIEW PROCESS

Daniel W. Osmun, P.E.19 William O. Engemoen, P.E.20 William R. Fiedler, P.E.21

ABSTRACT

The Bureau of Reclamation’s (Reclamation) processes for performing periodic reviews on dams have changed and evolved over time. In the mid-1990s Reclamation’s dam safety reviews shifted to focus on potential failure modes, and a probabilistic approach to dam safety risks was adopted. The goal of the Comprehensive Facility Review (CFR) process is to document the current condition and performance of a dam, assess the safety of the dam (by defining the potential failure modes and estimating their risks), and define dam safety activities and monitoring that should be performed to better define and reduce risk. The information developed in the process is used to identify the risk to the public, and help in prioritization of future dam safety activities. Although the process has been successful in accomplishing these goals, with at least two CFRs being performed on all Reclamation dams, it is believed that the process could be more efficient.

The new Comprehensive Review (CR) process involves updating existing reports from the previous CFR process and relies on a multi-disciplinary team, rather than a few individuals, to perform the review. In 2011 Reclamation performed a pilot program of the new CR process on 8 Reclamation dams, and 4 other dams under the jurisdiction of other Department of Interior (DOI) agencies (i.e. Bureau of Indian Affairs, Fish and Wildlife Service, National Park Service, Bureau of Land Management). Lessons learned from the pilot program influenced the new CR process. This paper describes the new CR process, the changes that Reclamation is implementing to the overall dam safety review process, and the benefits that the new CR process brings to Reclamation as well as other DOI Bureaus.

19 Geotechnical Engineer, Risk Advisory Team, Bureau of Reclamation, Technical Service Center, Denver, CO; 303-445-2980; [email protected]. 20 Geotechnical Engineer, Risk Advisory Team, Bureau of Reclamation, Technical Service Center, Denver, CO; 303-445-2960; [email protected]. 21 Civil Engineer, Risk Advisory Team, Bureau of Reclamation, Technical Service Center, Denver, CO; 303-445-3248; [email protected].

11 NOTES

12 THE TAUM SAUK DAM FAILURE WAS PREVENTABLE — HOW DO WE PREVENT THE NEXT OPERATIONAL DAM FAILURE?

David W. Lord, P.E.22

ABSTRACT

Taum Sauk Dam in Missouri overtopped and failed in December 2005. A number of factors contributed to the failure, including the lack of a spillway, changes to the project that decreased the already minimal freeboard, a lack of understanding of the original and current design basis of the project, inadequate electrical/mechanical equipment and controls, and an inadequate owner’s dam safety program (ODSP). Potential failure modes (PFMs) related to these factors are best described as operational failure modes. The risk of these types of failures is increasing because of operational changes at dams, caused by deregulation of utilities, environmentally required changes, and the increasing numbers of remotely operated dams. This paper discusses how the lessons learned from the failure of Taum Sauk Dam can be used to evaluate and protect all dams from overtopping failures.

Completing rigorous risk analysis procedures for operational PFMs often requires a very personnel and time-intensive process. Even with these rigorous procedures, many of the interactions of these complex systems will be missed because linear risk analyses cannot consider every interaction. Systems engineering does consider these interactions, but does not yet provide a fully developed framework for evaluating overtopping PFMs of dams like the risk procedures do. Dam owners need a simplified framework to begin to evaluate and manage operational failure modes without missing the complexity inherent in these systems. The framework should be broad enough to include very simple to very complex evaluations depending on the vulnerability of the dam to an overtopping failure. This paper proposes such a framework.

This overtopping protection framework (developed from the Pumped Storage Hydro- Electric Project Technical Guidance, October 5, 2007 and new FERC ODSP procedures) can be used to assess the vulnerability of projects to operational PFMs. The framework includes general procedures for analyzing the specific vulnerabilities of each dam and for reducing the likelihood of these types of failures. Using a combination of monitoring and rigorous management policies, the framework could prevent dam failures without needing to know the specific failure path or set of interactions that might cause a failure. Combined with guided use of risk analysis procedures, this could significantly reduce the risk of these failures.

22 Senior Civil Engineer, FERC, Division of Dam Safety and Inspections, Portland Regional Office, 503- 552-2728, [email protected]

13 NOTES

14 A DAM INCIDENT AT TABLE ROCK LAKE DAM

D. Wade Anderson, P.E.23 Elmo J. Webb, P.E.24 Bobby Van Cleave, P.E.25

ABSTRACT

Table Rock Dam, Power Plant and Auxiliary Spillway are located on the White River approximately 8 miles southwest of Branson in southwestern Missouri. Significant releases or failure of this dam would lead to catastrophic loss of life and significant economic loss in the Branson, MO and White River, MO area.

During the spring of 2011, extreme rainfall occurred over the White River Basin in Arkansas and Missouri. Table Rock Lake experienced record inflow, record releases, and a record pool. As the pool approached a new record pool and releases exceeded previous records, a slide developed on the upper downstream slope and extended to the crest of the dam. Operations personnel quickly notified the Dam Safety Officer who mobilized geotechnical and dam safety engineers. Once on site the engineers assured Operations, Water Management, and the Dam Safety Officer the dam was not at risk of failure. With the support and leadership of the Dam Safety Officer, the team of engineers further evaluated the condition of the dam and expeditiously developed a contract to repair the slide. The emergency contract was awarded within 4 days of the incident and repairs were completed within 14 days.

The response to this incident highlights the ability of Operations, Engineering and Construction, and Contracting personnel to respond to dam safety emergencies and how a focused team of multi-disciplined engineers from two districts were able to quickly evaluate, inform leadership, and respond to such an incident. Additionally, it emphasizes the need to have well trained and experienced engineers available to properly ascertain and design remediation efforts for dam safety deficiencies.

23 Dam Safety Program Manager, U.S. Army Engineer District, Tulsa, OK 74128, [email protected] 24 Civil Engineer, U.S. Army Engineer District, Little Rock, AR, 72201, [email protected] 25 Geotechnical Engineer, U.S. Army Engineer District, Little Rock, AR, 72201, [email protected]

15 NOTES

16 LOWER DAM REHABILITATION — FROM FERC TO DCR

Greg Zamensky, P.E.26 Mishelle Noble-Blair27 Greg Prelewicz, P.E.28

ABSTRACT

The Lower Occoquan Dam (Lower Dam) is owned and operated by Fairfax Water as part of their water supply and delivery system. The dam is also part of the Occoquan River Project, a small hydroelectric facility regulated by the Federal Energy Regulatory Commission (FERC). Fairfax Water is surrendering their FERC license due to considerable capital investment required to maintain the hydroelectric facilities. By surrendering the hydropower license, regulatory responsibility for the dam transitions from FERC to the Virginia Department of Conservation and Recreation (DCR).

The 60 year old Lower Dam is classified by FERC as a high hazard potential structure. The concrete gravity dam is a typical run-of-river structure with a height ranging from 10 to 30 feet and a length of about 500 feet. The spillway and non-overflow sections exhibited deteriorated and delaminated concrete along the crest and downstream slope. In addition, seepage was observed emanating from horizontal concrete lift joints and significant seepage (> 30 gpm) was observed coming from beneath one of the monoliths.

Before the surrender process can be completed, FERC required Fairfax Water to address the issues surrounding the Lower Occoquan Dam. Fairfax Water realized dealing with the Lower Dam meant satisfying FERC dam safety guidelines as well as Virginia dam safety regulations. The numerous and significant changes to the Virginia dam safety regulations between September 2008 and July 2010 created a moving target for Fairfax Water’s response plan including hazard classification and the inflow design flood.

With a surrender schedule in place, Fairfax Water needed to efficiently navigate FERC guidelines and Virginia dam safety regulations; evaluate the dam’s integrity and stability; assess disposition alternatives; decide how to move forward; and implement the plan. Rehabilitation plans have been prepared and construction is scheduled to begin in 2012.

26 Regional Practice Leader, Geo-Engineering Department – Dams, Levees, and Reservoirs Practice, Black & Veatch Water, Gaithersburg, MD 20879, [email protected] 27 Senior Plant Engineer – Griffith Water Treatment Plant, Fairfax Water, 9600 Ox Road, Lorton, VA 22079; [email protected] 28 Chief, Source Water Planning and Protection, Fairfax Water, 8560 Arlington Blvd, Fairfax, VA 22031, [email protected]

17 NOTES

18 CONSEQUENCE ESTIMATION DAM FAILURES

William Lehman 29 Jason Needham 30

ABSTRACT

HEC-FIA is a stand-alone, GIS-enabled model for estimating flood impacts due to flooding used by the United States Army Corps of Engineers. The software tool can generate required economic and population data for a study area from readily available data sets and use the data to compute urban and agricultural economic flood damage, area inundated, number of structures inundated, population at risk, and loss of life. These results can be used to inform risk assessments within the dam and levee safety programs as well as the Corps traditional planning process. All damage assessments in HEC-FIA are computed on a structure-by-structure basis using inundated area depth and arrival grids, or hydrograph data. The life loss computation contained in HEC-FIA includes consideration of the effectiveness of warning systems, community responses to alert, and evacuation of large populations.

HEC-FIA is also capable of analyzing economic and life safety benefits from various non-structural flood damage reduction measures, including installation of flood warning systems, public education campaigns, and flood-proofing or raising of individual structures. These estimates can be computed with uncertainty for single catastrophic failures, so that decision makers can be aware of which parameters contribute the most uncertainty to the life loss estimations.

29 Economist, Hydrologic Engineering Center, U.S. Army Corps of Engineers, Davis, CA, 95616, [email protected]. 2 30 Sr. Consequence Specialist, Risk Management Center, U.S. Army Corps of Engineers, Davis, CA, 95616, [email protected].

19 NOTES

20 DAM AND LEVEE SAFETY RISK ASSESSMENT — EVALUATION ROUTING AND LIFE LOSS ESTIMATION USING LIFESIM

Woodrow Fields, P.E.31 Chris Bahner, P.E., D. WRE32 Jason Needham33 Christopher R. Goodell, P.E., D. WRE34

ABSTRACT

LIFESim is a modular, spatially-distributed, dynamic simulation system for estimating potential life loss from dam and levee failure or non failure flood events that explicitly considers the primary factors contributing to life loss in a flood situation. LIFESim is the U.S. Army Corps of Engineers (USACE) most rigorous approach for estimating potential life loss due to dam failure, and it can be used to provide inputs for dam safety risk assessment. LIFESim considers detailed flood dynamics, loss of shelter, warning and evacuation, and uses historically-based fatality rates to estimate life loss.

The Warning and Evacuation Module spatially redistributes the population at risk from its initial distribution at the time that a warning is issued, to a new distribution with assigned flood zone categories at the time of arrival of the flood. USACE is in the process of improving the LIFESim evacuation-transportation process to account for defining initial escape routes based on shortest travel time and allowing evacuees to turn around if they come to a flooded road. USACE is also in the process of performing a comparison study to demonstrate that LIFESim is appropriate for a breach and/or overtopping scenario of a levee structure. In support of the comparison study, LIFESim was applied to two highly urbanized areas.

This paper provides an overview of LIFESim, discusses the changes to the evacuation- transportation process in LIFESim and their expected effects on life loss estimation, and presents development and results of LIFESim models for the one of the urbanized areas.

31 Hydraulic Engineer, U.S. Army Corps of Engineers, Institute For Water Resources, Hydrologic Engineering Center, 609 Second Street, Davis, CA 95616; ph: 530 756-1104; [email protected]. 32 Senior Hydraulic Engineer, WEST Consultants, Inc., 2601 25th Street SE, Suite 450, Salem, OR 97302, ph: 503-485-5409, [email protected]. 33 Senior Consequence Specialist, U.S. Army Corps of Engineers, Risk Management Center, 609 Second Street, Davis, CA 95616, ph: 503-756-1104, [email protected]. 34 Portland Office Manager/Senior Hydraulic Engineer, WEST Consultants, Inc., 103000 SW Greenburg Rd., Suite 470, Portland, OR 97223, ph: 503-946-8536, [email protected].

21 NOTES

22 MODELING ADAPTIVE THREATS: INCORPORATING A TERRORIST DECISION MODEL INTO SECURITY RISK ASSESSMENTS

Yev Kirpichevsky, PhD 35 Enrique E. Matheu, PhD 36 Yazmin Seda-Sanabria 37

ABSTRACT

This paper describes the development of a terrorist decision model, which can be used to systematically estimate the relative likelihood of potential attack scenarios for a given risk manager’s portfolio. The terrorist decision model is derived from information elicited from terrorism experts and intelligence analysts. Once the model is established through a baseline expert elicitation, it can be used to estimate threat for any number of attack scenarios and to accommodate additional scenarios without conducting new elicitations. The approach, which is based on the conjoint (trade-off) analysis methodology used frequently in market research, constitutes a unique contribution to the methods of eliciting expert uncertainty and aggregating expert opinions. The model can quantify the reduction of relative threat as a result of a particular risk mitigation strategy and, consequently, enable return-on-investment analyses for multiple risk mitigation alternatives. This paper describes the process used for identifying the key terrorist decision criteria that are assumed to have the greatest influence on their decision process, the expert elicitation process, the derivation of the terrorist decision model, and its application for estimation of relative likelihood of attack scenarios.

35 Research Staff Member, Strategy Forces, and Resources Division, Institute for Defense Analyses, Alexandria, VA 22311. 36 Chief, Dams Sector Branch, Office of Infrastructure Protection, National Protection and Programs Directorate, U.S. Department of Homeland Security, Washington, DC 20528. 37 National Program Manager, Critical Infrastructure Protection and Resilience Program, Office of Homeland Security, U.S. Army Corps of Engineers, Headquarters, Washington, DC 20314.

23 NOTES

24 SONAR FOR PROTECTION OF MARITIME STRUCTURES

Jason Curd, EIT38 L. Sebastian Bryson, Ph.D., P.E.39 Michael Kalinski, Ph.D., P.E.40

ABSTRACT

The prevention of attacks on marine structures has been an ongoing challenge and has created an awareness of the vulnerability of these structures to such attacks. Especially since the 9/11 era, it has become crucial for owners and operators of dams to protect them from underwater attacks and maintain a constant, secure perimeter that will provide immediate detection and tracking of all threats. Sonar provides a cost effective and efficient means of underwater security because unlike other methods of surveillance, acoustic waves with low to mid-range frequencies can travel virtually unimpeded through water until reflected back to the receiver. The center frequency and power levels are largely determinant of a sonar's performance, as well as the unique aspects of the marine environment where it will be used. This paper presents an evaluation of the uncertainties that exist underwater that can affect sonar performance. These uncertainties include the sound velocity profile (which shows the speed of sound underwater as a function of temperature, depth, and salinity), the signal-to-noise ratio, and the behavior of sound waves as they propagate through various mediums. This study determined that factors such as depth and variable sound profiles can lead to problems such as reverberation, multipath reflections, and poor range performance. Also, ambient noise associated with daily dam operation and recreational lake activity can result in false alarms and missed detections. However, it was concluded that when all of these factors are included in the deployment considerations, sonar provides adequate warning time to counteract approaching underwater threats.

38Research Assistant, Department of Civil Engineering, University of Kentucky, Lexington, KY 40506, [email protected] 39Assistant Professor, Department of Civil Engineering, University of Kentucky, Lexington, KY 40506, [email protected] 40 Hardin-Drnevich-Huang Professor, Department of Civil Engineering, University of Kentucky, Lexington, KY 40506, [email protected]

25 NOTES

26 DEFENSIVE DIRECTED ENERGY SYSTEMS FOR DAM SECURITY

Alexander D. Krumenacher, EIT41 L. Sebastian Bryson, Ph. D., P.E.42 Michael E. Kalinski, Ph. D., P.E.43

ABSTRACT

Protecting dams in the U.S. from potential terrorist attacks presents a unique challenge to dam owners and operators because of the risk of harming innocent boaters and swimmers. For this reason, it is advantageous for a dam owner to integrate less-than- lethal (LTL) defensive directed energy technologies into a protection mitigation strategy. A LTL defense strategy would help the dam operator ascertain the intentions of a potential threat, as a real threat will continue advancing in the midst of deterrence. To this end, a number of innovative defensive directed energy technologies are available. Although several of these technologies are under development, an increased awareness will undoubtedly expand the LTL technologies market. This paper describes the operating characteristics of an experimental surface technology and a subsurface technology that may possibly be effective in enforcing a safety zone around marine assets. The surface technology discussed, millimeter wave technology, is still in the early stages of development. This technology uses microwave energy focused into a beam, to heat the target’s skin without causing permanent damage. The subsurface technology discussed is the Sparker, which creates an acoustic pulse concurrently with a bright flash of light. Millimeter wave technology in its current state is cost prohibitive. However, continued development should result in decreasing costs. The Sparker is a more established technology, but has not yet been widely implemented for use in dam security. Regardless, both technologies will potentially provide a high level of deterrence without causing lethal or permanent damage to personnel, thereby limiting the personal injury liability for the asset owner. As only some of the two technologies performance information is accessible, actual performance must be inferred.

41 Research Assistant, Department of Civil Engineering, University of Kentucky, Lexington, KY 40506, [email protected] 42 Assistant Professor, Department of Civil Engineering, University of Kentucky, Lexington, KY 40506, [email protected] 43 Hardin-Drnevich-Huang Professor, Department of Civil Engineering, University of Kentucky, Lexington, KY 40506, [email protected]

27 NOTES

28 QUANTITATIVE RISK ANALYSIS FOR A DAM UNDER CONSTRUCTION IN SPAIN

Daniel Sanz-Jiménez, Civil Engineer44 Ignacio Escuder-Bueno, Civil Engineer, M.Sc., PhD45 Francisco Silva-Tulla, Civil Engineer, M.Sc., PhD46

ABSTRACT

Full quantitative risk assessment of Castrovido Dam (a gravity dam under construction) has included gathering and analyzing hydrologic data and projected conditions, working sessions to identify failure modes and make estimates by expert judgment as well as probabilistic analysis based on Monte Carlo simulations, among main tasks. The work is presented is particularly relevant as a complete example of a dam risk analysis during construction phase, with the benefit of drawing conclusions in advance to improve dam safety management. The most important point for stakeholders is the possibility of evaluating different scenarios, including the situation before and after dam construction, as well as the effect of the Dam Emergency Action Plan on risk reduction. Furthermore, this analysis can be used in the future (incorporating, for example, monitoring and surveillance outcomes) for reevaluating dam conditions within a continuous reviewing process, with the aim to achieve a more robust understanding for prioritizing investments and decision making. Finally, some considerations on USACE risk guidelines for new dams are made as uncertainties before finishing the construction and operating the dam have remarkable influence in risk estimates.

44 Confederación Hidrográfica del Duero, Valladolid, Spain. [email protected] 45 Universidad Politécnica de Valencia, Valencia, Spain. [email protected] 46 Lexinton, Massachussets, USA. [email protected]

29 NOTES

30 RECENT EXPERIENCE WITH ALKALI AGGREGATE REACTION EFFECTS IN CONCRETE DAMS

Dan D. Curtis47

ABSTRACT

Recently Hatch has been involved in numerous hydro projects where alkali aggregate reaction (AAR) has affected dams in several countries around the world. A finite element program has been developed to analyze the effects of concrete expansion on various dams, powerhouses and lock structures. The finite element program GROW3D has been calibrated to both displacement and stress measurements from various concrete dams. The objective of this paper is to present selected results from the analysis of various dams and how the effects of AAR have been managed. The effects of AAR on the stability of concrete dams will be discussed using a recent project. The Red Rock Dam AAR Project is given as a case history example and other AAR projects in the United States and Canada are briefly discussed. In some cases the effects of AAR have been beneficial to the stability of concrete dams.

47 Project Manager, HATCH Renewable Power, 4342 Queen Street, Suite 500, Niagara Falls, Ontario, Canada L2E 7J7; Tel: (905)357-6998; Fax (905) 374-1157; email: [email protected]

31 NOTES

32 ADDRESSING AAR STABILITY CONCERNS AT SANTEETLAH DAM

Jesse Kropelnicki48 Michael Sabad49 Paul F. Shiers50 Edith J. Butterworth51

ABSTRACT

The Santeetlah Development is one of four dams which comprise the Tapoco Project owned and operated by Alcoa Power Generating Inc. (APGI). The Santeetlah Development was originally constructed during the period 1926-1928 with modifications throughout its operating history. The project consists of an integral intake section, an arch section spanning between the massive left and right thrust blocks, and left and right wing wall non-overflow gravity sections. There exists evidence of continued alkali- aggregate reactivity (AAR) at the dam. Slots were cut in the right thrust block and left wing wall in 1950, in the left wing wall in 1999 and in the right thrust block in 2003 to relieve stresses from AAR growth.

A potential failure mode identified as part of the project’s PFMA session was AAR induced lifting of the thrust blocks resulting in instability and dam failure. To address these concerns, a finite element model (FEM) was created to analyze the effects of AAR induced growth on the stability of the dam.

The concrete expansion caused by AAR was modeled in the finite element analysis as a thermal load. In addition to the AAR loads, the FEM was used to evaluate the effect of gravity, hydrostatic, uplift and thermal loads. The AAR growth used in the model was calibrated to produce results matching field measured dam displacements. The measured field stresses were also considered in the calibration effort. Non-linear contact elements were modeled at the base of the dam and at joints between the wing wall, thrust block and arch. The factor of safety was calculated by lowering the friction angle at the base of the dam until the dam slid downstream. This friction angle was then compared to the friction angle of the rock to concrete contact to determine the factor of safety.

The paper will discuss use of this model to evaluate stability of the arch section and thrust blocks with and without reactivity, as well as the model development work that was needed to match the field measured displacements and stresses.

48 Jesse Kropelnicki, Lead Engineer, PB Americas, Inc., 75 Arlington St. Boston, MA 02116, (617) 960- 4975, [email protected] 49 Michael Sabad, Vice President, Alcoa Power Generating Inc., Tapoco Division, 300 North Hall Road, MS-T1521, Alcoa, TN 37701, (865) 977-2218, [email protected] 50 Paul F. Shiers, Senior Project Manager, PB Americas, Inc., 75 Arlington St. Boston, MA 02116, (617) 960-4990, [email protected] 51 Edith Butterworth, Engineer, PB Americas, Inc., 75 Arlington St. Boston, MA 02116, (617) 960-4829, [email protected]

33 NOTES

34 FREEZE-THAW DETERIORATION ON AGING STRUCTURES — STRUCTURAL ANALYSIS OF GERBER DAM

Hillery Venturini52

ABSTRACT

The structural analysis of Gerber Dam included addressing the existing concrete deterioration, continued damage progression due to freeze-thaw effects, and the resulting impacts on the structural integrity of the dam. Conditions of the dam were considered for two scenarios, existing and extreme. Existing conditions were represented by deterioration extending through 20 percent of the structure thickness. Extreme conditions were represented by deterioration extending through 40 percent of the structure thickness, which reflects a possible future condition. Damage was considered in both the vertical (along joints) and lateral (along lift lines) directions.

Results of the structural analysis showed that instability was driven by static loadings during normal operations and dynamic loadings associated with seismic event return intervals greater than 50,000 years. Structural factors considered include the existence of multiple unbonded lift lines, the current state of concrete deterioration, and the integrity of the existing reinforcement within the structure based on age and steel type. Results of the structural analysis aided in predicting that the stability of the structure would reach a critical state following approximately 40 years of continued operation and freeze-thaw cycles based on a deterioration rate of approximately 2-3 inches per 10 years.

Findings of the structural analysis illustrated that in general, damaged concrete was localized along the contraction joints and lift lines, which causes stress concentrations to develop at the intersection of these features. In addition, stress redistribution into the lower, thicker sections of the structure, was an apparent result of the reduction in concrete sections due to the deterioration.

52 Hillery Venturini, Civil Engineer, Structural Analysis Group, Bureau of Reclamation, Denver Federal Center, Bldg. 67, 4th Floor, P.O. Box 25007 (86-68110), Denver, CO 80225-0007, [email protected]

35 NOTES

36 SPILLWAY CHUTE SLAB CONCRETE DELAMINATION AND SPALLING DUE TO THERMAL EXPANSION

Daniel D. Mares, P.E.53

ABSTRACT

Concrete damage occurred adjacent to several spillway chute contraction joints. The worst location had a concrete spall five inches deep that extended about two feet downstream from the contraction joint. Other areas of drummy concrete were noted in areas both upstream and downstream of the spillway chute slab contraction joints.

In order to determine the cause of the concrete damage, instrumentation was installed to measure chute slab temperatures and joint displacements. Thermocouples were installed at various depths between 0.25 and 10.75 inches from the top of the concrete chute slab. Temperature and joint displacement data were electronically collected. Results of the temperature data indicated that the temperatures at the surface of the concrete were significantly higher than the ambient temperature. The data from the thermocouples also indicated that the concrete temperature declined with depth. During a typical summer day, the top thermocouple measured a daily maximum temperature of 130 degrees F. The low daily temperatures in the summer were about 60 degrees F for all the thermocouples. This resulted in a daily fluctuation in temperature near the surface of the chute concrete of 70 degrees F.

This paper discusses the cause of the concrete delamination and resulting spalling, considerations associated with potential failure modes due to offsets in flow surfaces and possible repair strategies.

53 Daniel D. Mares, P.E., Civil Engineer, Waterways and Concrete Dams Group, Bureau of Reclamation, [email protected].

37 NOTES

38 CONCRETE THERMAL STRAIN, SHRINKAGE AND CRACKING ANALYSIS FOR THE PANAMA CANAL THIRD SET OF LOCKS PROJECT

Vik Iso-Ahola, P.E.54 Bashar Sudah, P.E.55 Vincent Zipparro, P.E.56

ABSTRACT

The Panama Canal Authority (ACP) has undertaken the Panama Canal Expansion Program to increase the Canal’s capacity in order to meet the continuous growth in the number of transits and vessel size. The expansion of the Canal involves the construction of two new lock facilities, one on the Atlantic side and another on the Pacific side each with three chambers; the excavation of a new Pacific access channel to the new locks, and widening and deepening of the existing navigational channels and entrances; and increasing the elevation of Gatun Lake’s maximum operating level.

Two-dimensional and three-dimensional incremental finite element thermal analyses were performed using ANSYS software to estimate the temperature distribution within the new lock walls, lock heads, crossunders, central connections, and chamber conduits which consist of reinforced mass concrete structures. The estimated temperatures from the finite element model were used to estimate the thermal strains and potential for cracking using procedures outlined in ACI 207. The overall evaluation was used to determine optimal concrete placement temperatures, contraction joint spacing, and to comply with the Employer’s Requirements regarding concrete temperature gradient limitations. Potential for cracking due to drying shrinkage was also evaluated and crack depths were estimated based on the anticipated moisture distribution within the concrete structures.

This paper presents the thermal strain, drying shrinkage strain, and cracking potential analyses that have been performed for the new lock walls, lock head structures, and related concrete structures for the Panama Canal Third Set of Locks Project. The results of these analyses were used as key inputs to concrete mixes and their placement temperatures which are designed to withstand for 100 years the deleterious effects of seawater and load cycling of hydrostatic pressures during filling & emptying of lock chambers.

54 Principal Engineer, MWH Americas Inc., Walnut Creek, California, [email protected] 55 Structural Engineer, MWH Americas Inc., Walnut Creek, California, [email protected] 56 Design Engineer, Panama Canal Third Set of Locks Project, MWH Americas Inc., Chicago, Illinois, [email protected]

39 NOTES

40 HYDROMECHANICAL ANALYSIS FOR THE SAFETY ASSESSMENT OF A GRAVITY DAM

Maria Luísa Braga Farinha57 Eduardo M. Bretas58 José V. Lemos59

ABSTRACT

This paper presents a study on seepage in a gravity dam foundation carried out with a view to evaluating dam stability for the failure scenario of sliding along the dam/foundation interface. A discontinuous model of the dam foundation was developed, using the code UDEC, and a fully coupled mechanical-hydraulic analysis of the water flow through the rock mass discontinuities was carried out. The model was calibrated taking into account recorded data. Results of the coupled hydromechanical model were compared with those obtained assuming either that the joint hydraulic aperture remains constant or that the drainage system is clogged. Water pressures along the dam/foundation interface obtained with UDEC were compared with those obtained using the code DEC-DAM, specifically developed for dam analysis, which is also based on the Discrete Element Method but in which flow is modelled in a different way. Results confirm that traditional analysis methods, currently prescribed in various guidelines for dam design, may either underestimate or overestimate the value of uplift pressures. The method of strength reduction was used to estimate the stability of the dam/foundation system for different failure scenarios and the results were compared with those obtained using the simplified limit equilibrium approach. The relevance of using discontinuum models for the safety assessment of concrete dams is highlighted.

57 Research Engineer, Concrete Dams Department, LNEC – National Laboratory for Civil Engineering, Av. Brasil 101, 1700-066 Lisboa, Portugal, [email protected]. 58 PhD, Graduate Student, Universidade do Minho, Departamento de Engenharia Civil, P-4800-058 Guimarães, Portugal, [email protected]. 59 Senior Research Engineer, Concrete Dams Department, LNEC – National Laboratory for Civil Engineering, Av. Brasil 101, 1700-066 Lisboa, Portugal, [email protected].

41 NOTES

42 AUTOMATIC DATA ACQUISITION SYSTEM AT SANTEETLAH DAM

Kevin Finn60 Alvin Diamond61 Michael Sabad62 Paul Shiers63 Jesse Kropelnicki64

ABSTRACT

The Santeetlah Development is one of four dams which comprise the Tapoco Project owned and operated by Alcoa Power Generating Inc. (APGI). The Santeetlah Development was originally constructed during the period 1926-1928 with modifications throughout its operating history. The project consists of an integral intake section, an arch section spanning between the massive left and right thrust blocks, and left and right wing wall non-overflow gravity sections.

The dam is continuously monitored by an Automatic Data Acquisition System (ADAS) for the purpose of evaluating dam performance and safety, in light of the age of the structures and observed alkali aggregate reactivity (AAR) growth at the dam. The present instrumentation program for the Santeetlah Development consists of horizontal and vertical survey points, inclinometers, multi position mechanical extensometers, vibrating wire piezometers, seepage monitoring locations, one dimensional and three dimensional crackmeters, and reservoir and tailwater level monitoring devices.

Since construction of the dam, the instrumentation program has evolved to meet the demands of maintenance and monitoring projects at the site. This includes instrumentation installed to quantify the reduction of stresses in the dam during major slot cutting activities, and routine upgrades to the instruments and control systems to match changing technologies.

The paper will discuss the ADAS system, and improvements to the system to allow for future upgrades to the monitoring program as well as its use to evaluate the performance of the existing dam structures.

60 Kevin Finn, Engineer, PB Americas, Inc., 75 Arlington St., Boston, MA 02116, (617) 960-5031, [email protected] 61 Alvin Diamond, P.E., Alcoa Power Generating Inc., Tapoco Division, 300 North Hall Road, MS-T1521, Alcoa, TN 37701, (865) 977-2759, [email protected] 62 Michael Sabad, Vice President, Alcoa Power Generating Inc., Tapoco Division, 300 North Hall Road, MS-T1521, Alcoa, TN 37701, (865) 977-2218, [email protected] 63 Paul Shiers, Senior Project Manager, PB Americas, Inc., 75 Arlington St., Boston, MA 02116, (617) 960- 4990, [email protected] 64 Jesse Kropelnicki, Lead Engineer, PB Americas, Inc., 75 Arlington St. Boston, MA 02116, (617) 960- 4975, [email protected]

43 NOTES

44 INVESTIGATION AND EVALUATION OF SEEPAGE CONDITIONS AND POTENTIAL FAILURE MODES AROUND OUTLET CONDUITS

Keith A. Ferguson, P.E.65

ABSTRACT Evaluation of potential seepage failure modes in embankment dams and in particular around outlet works penetrations is a very important aspect of dam safety evaluations. Assessing potential seepage failure modes typically requires designing and evaluating investigation and instrumentation programs. Experience has shown that adverse seepage and piping conditions can develop and remain difficult to detect until the failure mode is in an advanced stage of the continuation phase of the failure mode development process (Appendix O, ER 1110-2-1156). In this paper both the theoretical considerations and practical observations of seepage conditions around conduits will be supported with case history information from two large outlet works conduits through embankment dams on relatively deep alluvial foundations: Lake Darling Dam, North Dakota, and Lake Isabella Auxiliary Dam, California. In both cases, large twin barrel cast-in-place reinforced concrete outlet conduits were constructed with partial cut and cover methods. The conduits were placed on relatively thick alluvial foundation soil deposits and operated for extended periods of time before detailed safety evaluation studies were initiated. These case histories reveal how the identification of small unfiltered defects in and around the conduits is critical to the assessment of the potential for the initiation of seepage and piping failure modes. Once initiation has occurred, the small and insidious nature of erosion pipes that develop during the early stages of the failure mode makes direct detection almost an impossible task. Even with extensive investigation and instrumentation monitoring programs, the assessment of the safety of these structures is a very difficult task and requires extensive experience and keen engineering insight and judgment.

65 National Practice Leader for Dams, Levees, and Hydraulic Structures, HDR Engineering, Inc., 303 East 17th Avenue, Suite 700, Denver, CO 80203-1256, [email protected], 303-764-1546.

45 NOTES

46 SELF MONITORING LEVEES: HOW CLOSE ARE WE?

Dennis M. Kamber66 Harry R. Kolar67 Rob Vining68

ABSTRACT

When you turn the ignition key in your car, the instrument panel is illuminated with a range of lights, and other indicators. They provide an overview of various functions and safety features. You are advised of fluid levels; engine and outdoor temperature; tire pressure; and brake status. Additionally, you are alerted if your doors are ajar or to fasten your seat belt, and automatically connected to wireless communication devices. In a matter of seconds, you are apprised of the vehicle status, and advised of safety concerns. Can we cost effectively apply analogous technologies to our levee systems in order to provide indications of condition and areas of distress?

The quick answer is; yes, but the extent of self-monitoring will depend on a number of circumstances. Traditionally we inspect levees primarily by visual observation, and occasionally utilize minor invasive testing. However, very little is generally known about condition of the interior of the flood defense structure, and therefore provides very little data to support our crucial decision making ranging from repair priority to evacuation. Technology continues to advance, providing us with an array of in-situ and remote sensing devices, cameras, membranes, fiber optics, and data transmission techniques. This discussion will look at these technologies and the practicality for using them in both existing and planned levees. Included is an overview of how these devices can be integrated to create a dashboard that provides an indication of condition, and extent of distress. Storm, localized weather, waterway surge, and other predictive models can be linked to the dashboard to enhance risk management decisions by the responsible manager. Also, the topic will look at advanced technologies currently in development that have applicability to intelligent levees in the future.

66 Senior Vice President, Global Water Management, ARCADIS, Washington, DC 20037, [email protected] 67 Distinguished Engineer, IBM Research, Yorktown Heights, NY 10598, [email protected] 68 Vice President, HNTB, Santa Ana, CA 92707, [email protected]

47 NOTES

48 DEVELOPING EMBANKMENT DAM FRAGILITIES FOR EMERGENCY MODELING AND RESPONSE

Yogesh Prashar, PE, GE69 Atta B. Yiadom, PE70 Elizabeth Bialek, PE71

ABSTRACT

This paper discusses the approach to developing fragilities for the embankment dams in the East Bay Municipal Utility District (EBMUD) Service Area. The goal is to approximately model the performance of these embankment dams during a seismic event and to help allocate resources for post-earthquake inspection. EBMUD has developed Marconi, an open-source emergency management software that integrates seismic model results with emergency response. By inputting the fragility data of these dams into the software, EBMUD can predict which dams are most likely to suffer damage and therefore prioritize immediate post-seismic response. As part of its Dam Safety Program, EBMUD had already completed the seismic stability evaluation of most of the 29 dams under consideration. These results of which were used to develop the seismic dam fragilities. Many of the dams in this study are under the jurisdiction of the California Department of Water Resources, Division of Safety of Dams (DSOD) and all the dams conform to the regulatory agency high standards of performance under static and earthquake loading conditions. Using the ShakeCast developed by USGS we are able to identify ground motion parameters at the 29 sites and rapidly predict the expected behavior given the fragility of each facility. The approach of this assessment and how it will be used to prioritize deployment of emergency staff is explained in the paper. The approach can easily be applied and implemented by water agencies, utilities or entities with critical infrastructure in areas of high seismicity.

69 Associate Civil Engineer, East Bay Municipal Utility District, Engineering and Construction Department, Engineering Services Division, 375 11th Street, MS #610, Oakland, CA 94607. 70 Senior Civil Engineer, East Bay Municipal Utility District, Engineering and Construction Department, , Engineering Services Division, 375 11th Street, MS #610, Oakland, CA 94607. 71 Engineering Services Division Manager, East Bay Municipal Utility District, Engineering and Construction Department, , Engineering Services Division, 375 11th Street, MS #805, Oakland, CA 94607.

49 NOTES

50 APPLICATION OF ACOUSTIC IMAGING FOR UNDERWATER SUBSTRUCTURE INSPECTION AND MAPPING

Kenneth J. LaBry72

ABSTRACT

This discussion presents a system and methodology for the application of high definition Underwater Acoustic Imaging (UAI) in the inspection of submerged structures and the interfaces of those structures with the surrounding water bottom. The UAI methodology utilizes an integrated remote sensing platform to visualize and quantify underwater structures and any external abnormalities associated with the structures, and adjacent water bottom surfaces.

The presentation demonstrates the pitfalls and problems associated with acoustic sonar utilization in substructure inspection and shallow environments, the environmental difficulties, cost effectiveness, and benefits, as well as result capabilities and integration of data sets from the underwater remote sensing systems, High Definition Laser Scanning and surface topography into a comprehensive geo-referenced model of a structure system and the adjacent land mass. It outlines the basic acoustic principles involved in the inspection of substructures, the development of remote sensing equipment capable of generating the necessary resolution and definition for shallow environments, as well as the development of the techniques and methodologies necessary for proper execution of substructure inspections and comprehensive shallow water bottom surface mapping. The discussion also encompasses remarks regarding the economic advantages of remote sensing in substructure inspections.

Several case study examples are shown and briefly discussed. The examples depict integrated modeling capabilities for depicting the inspection results, and a discussion of the problems overcome with execution and data assimilation for a specific case.

72 Kenneth J. LaBry, Manager – Underwater Acoustics Group, FENSTERMAKER, 205 Paddington Dr., Lafayette, LA 70508, [email protected]

51 NOTES

52 IMPROVED CHARACTERIZATION OF DAMS, RESERVOIRS, LEVEES AND OTHER WATER-RELATED INFRASTRUCTURE THROUGH DETAILED MULTI-SENSOR SURVEYING

Todd Mitchell, Certified Mapping Scientist73

ABSTRACT

A growing demand for detailed characterization of cartographic, geophysical, geotechnical and geologic conditions related to water impoundment infrastructure highlights the critical need for surveying methodologies that provide new levels of detail. Integration of multibeam bathymetry and mobile laser scanning survey sensors onto a single waterborne vessel allow for efficient surveys. Through collected data, engineers, operators and maintenance personnel in multiple disciplines have the opportunity to perform virtual inspection of the infrastructure site. Capture of integrated topography and bathymetry is vital for engineering design, change detection, as well as identifying geohazards endangering the site. This also extends into mapping of near-surface geology and stratigraphy, which play a critical role in site evaluation and risk assessment, especially in areas of steep terrain or complex depositional environments. The ability to map features and characterize conditions both above and below the waterline can provide valuable forensic information regarding historical landslide events and alluvial stratigraphic complexities. Sedimentation issues are also frequently a concern when establishing, maintaining and removing dams as well as in monitoring rivers and levees. The merging of multiple sensors’ data spanning the waterline can provide additional information for modeling flow dynamics, sediment transport and sediment characteristics. Hydraulic modeling also benefits from being able to characterize flood events that extend to the top of a water channel/reservoir. A data set collected from these surveys can allow hydraulic engineers to take cross-sections at any interval for 1D hydraulic models or to populate mesh vertex elevations in 2D models, even when using an extremely dense mesh. This paper will discuss examples of utilization of this technology set.

73 Fugro Consultants, Inc., 4820 McGrath Street #100, Ventura, CA, 93003, 805-650-700, [email protected]

53 NOTES

54 3D TOPOGRAPHIC INTEGRATION METHOD ON INTERIOR AND EXTERIOR FLOODPLAINS OF LEVEES USING LIDAR AND SONAR DATA

Myung Hee Jo74 Hyen Cheol Park75 Jun Ho Song 76 Yun Jae Choung77

ABSTRACT

The topographic establishment of interior and exterior floodplains located mainly along the embankment line of the area next to a river is important in regard to the protection of the river environment and the related ecosystem, the development and management of the area next to a river, and the simulation related to flooding. In particular, the underwater topographic monitoring process which causes changes to a river bed is significant for the construction of an embankment and the estimation of a dredging amount for interior and exterior floodplains. In the past, a number of ground measuring technologies were used to extract such topographic information of a river. However, such tools as LiDAR, SONAR, a single beam and a multi-beam have recently been used in such countries as the US. This study focuses on the topographic establishment of a precise river structure including interior and exterior floodplains in order to obtain the information of major infrastructure and construct a database for the 4 Major River Project which is currently being executed by the government of South Korea. For such a purpose, the LiDAR data has been used for the interior floodplain of an embankment, while the SONAR data has been utilized for the exterior floodplain. For the continuous indication of such data, the Mosaic tool of EDARS Imagine has been used. By executing a continuous monitoring process for the topography of a river, it will be possible to extract topographic data for the cross section of a river bed and check the current state regarding changes to a river bed in the future. Also, while executing the continuous monitoring process for changes to a river bed, which could possibly lead to a flood, it will be possible to establish a dredging plan, organize a river channel for the maintenance of a river bed, and manage a riverside and a crossing structure.

74 Dept. of Satellite Geoinformatics Engineering, Kyungil University, Gyeongsan-si, Gyeongsangbuk-do, Republic of Korea, Email: [email protected] 75 Institute of Spatial Information Technology Research, GEO C&I Co., Ltd., Gyeongsan-si, Gyeongsangbuk-do, Republic of Korea, Email: [email protected] 76Institute of Spatial Information Technology Research, GEO C&I Co., Ltd., Gyeongsan-si, Gyeongsangbuk-do, Republic of Korea, Email: [email protected] 77 Institute of Spatial Information Technology Research, U&GIT Co., Ltd., Gyeongsan-si, Gyeongsangbuk- do, Republic of Korea, Email: [email protected]

55 NOTES

56 DISCUSSION OF MODELING FOR ANALYSES OF FULLY SOFTENED LEVEES

Danny K. McCook78

ABSTRACT

Levees and embankments constructed of highly plastic clays are susceptible to a special kind of instability often referred to as surficial or sloughing slides. Highly plastic clay soils become desiccated over time from repeated drying cycles and develop a pronounced blocky, open structure. When a heavy rainfall closely follows an extended droughty period, the cracks in the blocky structured clay become full of water and interfaces between the blocks in the clay become saturated. The process of repeated wetting and drying creates what has been termed a “softening” process. The result is a translational movement of the desiccated zone in the levee.

This phenomenon is particularly severe in southern climates such as Texas, Mississippi, and Louisiana. The accepted state of the art for modeling the shear strength of these soils for this condition is to use the fully softened shear strengths. These shear strengths may be based on either specialized laboratory testing or empirical methods. This paper discusses the way that empirical methods developed by Stephen Wright, based on the work done by Stark and Eids, as well as the Stark empirical estimate, can be employed to obtain safety factors for preliminary analyses. Comparisons are presented for safety factors obtained by detailed laboratory testing done by the USACE on a project versus the empirical estimates for several design examples.

The paper also discusses appropriate safety factors and implications of various modeling assumptions to the design of levees. Factors such as assumed depth of desiccation, involvement of foundation soils in the model, and others are examined and summarized. Finally, recommendations are provided on methods that are practical and useful for designing levees where detailed laboratory testing may not be justified.

78 Danny K. McCook, McCook Geotechnical Engineering, PLLC, 3221 Rosehaven Drive, Unit 1510, Fort Worth, TX 76116, [email protected], [email protected]

57 NOTES

58 UTILIZING GEOPHYSICS IN AUXILIARY SPILLWAY INTEGRITY EVALUATION

Cari R. Beenenga, P.E.79 L. Andrew Deichert, P.E.80 Joseph M. Seybert, P.E.81 David M. Snyder, P.E.82

ABSTRACT

This paper will discuss the geophysical and geotechnical techniques performed at two U.S. Department of Agriculture (USDA), Natural Resources Conservation Service (NRCS) earth embankment dams. New Creek Site 14 Dam, south of Keyser, WV, constructed in 1963, is approximately 114 feet high. Upper Deckers Creek Site 1 Dam, west of Reedsville, WV, constructed in 1969, is approximately 45 feet high. Both dams have grass-lined auxiliary spillways constructed as side hill cuts in the abutment. Project site geology consists primarily of shale, sandstone, siltstone and minor amounts of limestone and coal. At the New Creek Dam site these geologic units are overturned and have nearly vertical bedding.

Gannett Fleming is the designer working with NRCS on the rehabilitation of these dams. The dams are being upgraded to meet current design standards. Geophysical efforts were undertaken at each site to assist with the creation of a subsurface profile along the entire length of the grass-lined spillways. Seismic refraction and MASW (multi-channel analysis of surface waves) technologies were utilized to assist in determination of engineering parameters for the SITES computer program. Data provided by these techniques were validated through traditional geotechnical test borings, test pits and laboratory testing of the collected soil and rock samples. Headcut erodibility analyses using the SITES computer program were completed by Gannett Fleming as part of the designs.

The paper will explain the technology and method by which seismic refraction and MASW data were utilized. Reliability, value and economics related to use of geophysical technology will be discussed as conclusions.

79 Gannett Fleming, Inc., Geotechnical Project Manager, P. O. Box 67100, Harrisburg, PA 17106; PH 717- 763-7211; FAX 717-303-0346; email: [email protected] 80 US Department of Agriculture, Natural Resources Conservation Service, Civil Engineer, 1550 Earl Core Road, Suite 200, Morgantown, WV 26505; PH 304-284-7563; FAX 304-284-4839; email: [email protected] 81 US Department of Agriculture, Natural Resources Conservation Service, Civil Engineer, 1550 Earl Core Road, Suite 200, Morgantown, WV 26505; PH 304-284-7567; FAX 304-284-4839; email: [email protected] 82 Gannett Fleming, Inc., Geotechnical Project Engineer, P.O. Box 67100, Harrisburg, PA 17106; PH 717- 763-7211; FAX 717-303-0346; email: [email protected]

59 NOTES

60 A LARGE SCALE RESONANT COLUMN TESTING SYSTEM FOR EVALUATING DYNAMIC PROPERTIES OF GRAVELLY FILL MATERIALS OF DAMS

Nam-Ryong Kim83 Dong-Hoon Shin84 Ik-Soo Ha85 Min-Seub Kim86

ABSTRACT

This article introduces a large scale resonant column testing apparatus to evaluate small- strain shear modulus, damping ratio, and the modulus reduction curve corresponding to shear strain level of gravelly soils. These key parameters are important for the seismic analysis of geotechnical systems such as earth embankment dams and the main purpose of this new testing system is focusing on the characterization of gravelly fill materials for dam construction. Detailed configurations of the fixed-free Stokoe type resonant column testing apparatus which can test 200mm in diameter specimen are introduced, and the system was calibrated. A series of tests for gravelly fill material have been conducted on large scale specimens 200mm in diameter and 400mm in height. The result and applicability of this testing apparatus to evaluate dynamic properties of gravelly fill materials is addressed. Finally, the applicability of this new system is discussed.

83 K-water Institute, 462-1 Jeonmin, Yuseong, Daejeon, Korea, +82-42-870-7632, [email protected] 84 K-water Institute, 462-1 Jeonmin, Yuseong, Daejeon, Korea, +82-42-870-7600, [email protected] 85 K-water Institute, 462-1 Jeonmin, Yuseong, Daejeon, Korea, +82-42-870-7603, [email protected] 86 K-water Institute, 462-1 Jeonmin, Yuseong, Daejeon, Korea, +82-42-870-7613, [email protected]

61 NOTES

62 RAGGED MOUNTAIN DAM — THE TWISTS AND TURNS OF SELECTING AND DESIGNING A NEW DAM

Randall P. Bass, P.E. 87 Jennifer A. Whitaker, P.E.88 Douglas J. March, P.E.89 Thomas Frederick, P.E.90

ABSTRACT

The Rivanna Water and Sewer Authority (RWSA) is an independent, wholesaling water agency that owns and operates various facilities for the impoundment, treatment, and transmission of potable water, as well as the collection and treatment of wastewater. Included in the assets or facilities that the RWSA owns and/or operates are a series of raw water impoundments/reservoirs. In 2004, the RWSA concluded that the demand for a reliable source of water was approaching the safe yield of the existing impoundment and set forth with engineering evaluations to select the best options for providing a safe and reliable raw water source for the next 50 years. In 2006, a water plan that included the enlargement of the existing Lower Ragged Mountain Reservoir was approved by Albemarle County and the City of Charlottesville, Virginia.

The existing Lower Ragged Mountain reservoir is impounded by a cyclopean gravity dam that was constructed in 1908. Due to a seriously inadequate spillway system and possible stability issues, the Lower Ragged Mountain Dam is considered unsafe by the Dam Safety Program, Department of Conservation and Recreation (DCR). Early indications suggested that a new enlarged dam could be located immediately downstream of the existing dam. A Roller Compacted Concrete (RCC) gravity structure was initially selected as the preferred alternative for the proposed new dam.

This paper will present the trials and tribulations of how the RCC gravity dam option changed over time to an earth fill dam. Also, the paper will discuss some design elements of the new 125 foot tall earth fill dam and how the design incorporates a future increase in the normal pool elevation of 12 feet.

87 Schnabel Engineering, Inc., 6445 Shiloh Road, Suite A, Alpharetta, GA 30005; [email protected] 88 Rivanna Water & Sewer Authority, 695 Moores Creek Lane, Charlottesville, VA 22902 89 Rivanna Water & Sewer Authority, 695 Moores Creek Lane, Charlottesville, VA 22902 90 Rivanna Water & Sewer Authority, 695 Moores Creek Lane, Charlottesville, VA 22902

63 NOTES

64 SEEPAGE CONTROL AND MONITORING AT TWO EXISTING COLORADO EARTHEN EMBANKMENT DAMS

Doug Yadon, PE, GE, PG, CEG,91 Ron Sanchez, PE,92 Andy Funchess,93 Pat Schmidt, PLE94 Dave Mason, PLE95

ABSTRACT

Work was recently completed at Rampart Dam and Reservoir and Gold Camp Dam and Reservoir as part of an ongoing program of dam safety upgrades by Colorado Springs Utilities (UTILITIES). Rampart and Gold Camp Dams are zoned earthen embankments constructed from decomposed Pikes Peak granite – “dg”. Horizontal seepage through more permeable zones in the embankments emerged on the downstream slopes some time after initial filling. The seepage at Gold Camp Dam was found in prior studies to result in locally high internal pore pressures in the downstream shell of the 103-foot high embankment. These pore pressures resulted in factors of safety against downstream slope failure that fell below dam safety standards, and concerns were identified that piping (internal erosion) could develop. Similarly, a zone of perched horizontal seepage emerged on the mid-downstream slope of the 230-foot high Rampart Dam. Although analyses demonstrated that slope stability met standards, a concern remained that piping of the “dg” might occur.

Two very different approaches address the potential seepage-related failure modes at these dams. The work at Gold Camp Dam involved design and construction of a new upstream slope geosynthetic liner to replace the original 25-year old liner. The new liner maintains downstream slope stability by keeping seepage and pore pressures in the downstream shell at safe levels; monitoring of existing piezometers and the seepage collection system will continue. At Rampart Dam the sufficient and more cost-effective solution was to control piping potential where seepage emerged on the mid downstream slope. A new filter-protected seepage collection system was designed and constructed to replace an existing but non-functional system. The new system is comprised of a two- stage filter and drain trench/blanket with a slotted PVC collection pipe conveying seepage to an existing flow measurement vault with real-time data transmission to the UTILITIES Operations Center.

91 Senior Geotechnical Engineer, AECOM Technical Services, Inc., 717 17th Street, Suite 2600, Denver, Colorado 80502, 303.542.4755,[email protected]. 92 Managing Engineer, Colorado Springs Utilities, Water Planning and Design, 1521 Hancock Expressway, MC 1821, Colorado Springs, CO 80947, 719-668-8611, [email protected]. 93 Field Operations Manager, Colorado Springs Utilities, 456 W. Fontanero Street, P.O. Box 1103, Mail Code 1210, Colorado Springs, Colorado 80947-1210, 719.668.3819, [email protected]. 94 Project Manager ,Colorado Springs Utilities, Water Planning and Design, 1521 Hancock Expressway, Colorado Springs, CO 80903, 719.668.4485, [email protected]. 95 Project Manager, Colorado Springs Utilities, Water Planning and Design, 1521 Hancock Expressway, Colorado Springs, CO 80903, 719.668.4485, [email protected].

65 NOTES

66 RISK INFORMED DECISION MAKING INFLUENCES ON THE ASHTON DAM REMEDIATION PROJECT DESIGN

Roger L. Raeburn, P.E.96 Jennifer L. Williams, P.E.97 Frank L. Blackett, P.E.98

ABSTRACT

At 65 feet high and 252 feet long, Ashton Dam is a semi-zoned earth and rockfill dam on the Henry’s Fork River in Eastern Idaho. Completed in 1916, Ashton Dam is the only remaining example of four similarly designed dams of that era. Since its construction the dam has experienced sinkholes and sediment plumes. In 1991 the dam’s owners made significant modifications to facilitate passage of the probable maximum flood that included lowering of the crest, construction of a roller compacted concrete overlay, and seismic stabilization of the upstream face. The Ashton–St. Anthony Hydroelectric Project is licensed with the Federal Energy Regulatory Commission and classified as high hazard potential.

The dam’s core is considered to be in a meta-stable condition; that is to say the core has experienced some deterioration and potential internal erosion of the fine grained low- plastic silt core material into and through downstream embankment zones, as evidenced by the historic occurrence of sinkholes and pluming. An increase in the crest’s settlement since 1991 is confirmation that the failure mode is progressing at an increasing rate. In response to these symptoms, PacifiCorp implemented risk reduction measures including lowering the reservoir and implementation of an enhanced monitoring program while the remediation plan is developed. A risk assessment was performed to aid in the remediation evaluation process, resulting in significant changes to some alternatives and the final remediation design. The risk assessment identified inadequacies in some proposed remediation alternative designs that may have exacerbated the potential for foundation seepage and piping, resulting in more problems than it would fix. This paper provides a brief history of the dam’s performance, how the risk analysis was used to scope both the geotechnical investigations, and the development of a comprehensive remediation design to be implemented.

96 PacifiCorp, 825 NE Multnomah St., Portland, OR 97232, [email protected] 97 URS Corporation, 8181 E Tufts Ave, Denver, CO 80237, [email protected] 98 Federal Energy Regulatory Commission, 805 SW Broadway, Suite 550, Portland, OR 97205, [email protected].

67 NOTES

68 CASE STUDY: BLAKELY MOUNTAIN DAM

Ben Emery99

ABSTRACT

Blakely Mountain Dam, a 1,100 foot long, 205 foot high earthen dam, which forms Lake Ouachita, is located approximately 10 miles NW of Hot Springs, AR. This project was placed in service in August 1953 and is currently being evaluated for concerns regarding seepage and piping failure modes of the dam. Blakely Mountain Dam was built with a gravel drain abutting against the impervious core for 3,300 square feet along the length of the dam. This gravel drain does not meet filter criteria for the impervious core materials and therefore may lead to piping of the core material.

Construction of a 2 million dollar seepage collection system consisting of an impervious berm with 10 manholes, ditches, and a V-notch weir was completed in October 2009 to monitor flow through the dam. Three manholes were equipped with turbidity meters to monitor soil particles movement through the system.

Between November 2010 and January 2011, the collection system had no flow. This prompted the Vicksburg district to test for possible leaks throughout the dam, which may cause water and possible piped material to bypass the seepage collection system. In January 2011, a dye test was performed on the dam. This consisted of pumping highly concentrated dye into the blanket drain and monitoring for leakage. To date no evidence of piping has been observed. An Issue Evaluation Study (IES) for Blakely commenced this past March. This presentation will profile the dam’s history, results of recent tests, and the outcome of the IES.

99 Geotechnical Engineer, USACE, Vicksburg District, Inspection and Investigation Section, 4155 Clay St, Vicksburg, MS 39183, [email protected]

69 NOTES

70 EVALUATION OF PHREATIC LINE IN HOMOGENEOUS EARTH DAMS WITH DIFFERENT DRAINAGE SYSTEMS

R. Ziaie Moayed100 V. Rashidian101 E. Izadi102

ABSTRACT

The phreatic surface in earth dams should be kept at or below the downstream toe. The phreatic surface within a dam can be controlled by properly designed drain. This paper presents a numerical evaluation of phreatic line location within an earth dam with different drainage systems in both steady-state and rapid drawdown condition of reservoir water table. Toe drain, horizontal drainage blanket and chimney drain effects on phreatic line have been studied. The results have been compared with the case of no drainage system. It is found that, in steady-state condition, the toe drain installation is just in an effort to prevent softening and erosion of the downstream toe and its efficiency attenuate as the dam height increase. By the use of horizontal drainage blanket, the phreatic line recedes from the downstream slope and when the chimney drain is installed the phreatic line tends to remain mainly in upstream side so the seepage will not continue throughout the embankment. In rapid drawdown condition, in which the important matter is pore pressure dissipation within the embankment, it was observed that the phreatic line height and its corresponding pore pressure are decreased faster in the dam with chimney drain than the dam with toe or blanket drain.

100Associate Professor, Civil Engineering Department, Imam Khomeini International University, Qazvin, Iran (phone: 281-837-1153; fax: 281-837-1153; E-mail: [email protected]). 101M.Sc. Student, Civil Engineering Department, Imam Khomeini International University, Qazvin, Iran (E-mail: [email protected]; [email protected]). 102M.Sc. Student, Civil Engineering Department, Imam Khomeini International University, Qazvin, Iran (E-mail: [email protected]).

71 NOTES

72 SEABROOK SECTOR GATE COMPLEX GEOTECHNICAL CONSIDERATIONS AND ISSUES

Robert (Bob) Chamlee, P.E.103

ABSTRACT

The Seabrook complex features a 95-foot opening sector gate flanked by two 50-foot opening vertical lift gates and tie-in T walls that connect to the existing hurricane protection to the east and west. The project is located at the northern terminus of the Inner Harbor Navigation Canal (IHNC), near Lake Pontchartrain, in New Orleans, Louisiana. The project is being constructed for the U.S. Army Corps of Engineers (USACE) under the Early Contractor Involvement (ECI) contracting method.

Several geotechnical issues had to be addressed during design. For starters, key components of the project were located over a deep scour hole in the canal. The scour hole was as deep as 85 feet below the water surface. The scour hole had to be filled to foundation grade. Filling with clean sand was the method selected. Vibro-compaction was selected to densify the material in-situ. Filling the scour hole with clean sand resulted in a pervious foundation. Seepage had to be addressed for both the permanent structures as well as the cofferdam.

All structures for the Seabrook complex are pile supported. Pile design had to consider vertical and lateral loading. A test pile program was conducted but it was performed on the canal bank and could not duplicate all foundation conditions, thus requiring some interpolation to model some pile sections or design with a higher factor of safety.

The north wall of the cofferdam was designed to provide the interior storm protection required for the June 2011 hurricane season. Construction completion is scheduled for June 2012.

103 Lead Geotechnical Engineer, ARCADIS, 1210 Premier Drive, Suite 200, Chattanooga, TN 37421, Phone: 423-756-7193; e-mail: [email protected]

73 NOTES

74 LEVEE CUTOFF WALL DESIGN AND CONSTRUCTION THROUGH LOOSE SACRAMENTO RIVER SILTS

Jonathan W. Pease, Ph.D., G.E.104 Christopher R. Nardi, P.E., G.E.105

ABSTRACT

A 10-mile stretch of Sacramento River east levee improvements near Sacramento, California, is underlain by very weak low-plasticity to non-plastic silts. These soils are commonly characterized by SPT blowcounts of 0 to 5 blows per foot for 20 to 35 feet depth below grade. A detailed subsurface exploration program with high quality sampling and laboratory testing, cone penetration testing (CPT), and vane shear testing (VST) was performed to characterize these soils to assess stability of cutoff walls at the toe of the existing levee. Cut-off-wall slurry trench stability and end-of-construction levee slope stability were modeled with SHANSEP undrained strengths. Construction instrumentation including inclinometers, vibrating wire piezometers, and settlement sensors were installed between the existing levee and slurry trench as part of construction instrumentation, as well as additional sampling and testing to verify strength assumptions. Results of inclinometer measurements showed both slurry and vertical- auger method cutoff walls experienced the greatest lateral deformation following completion of the backfill. This is attributed to horizontal consolidation of the soil bentonite backfill. Trench settlement was generally small within the 21 day settlement period, but lateral movement continued for a considerably longer duration and appears to match the time rate of consolidation curve for a 3-foot-thick double-draining layer.

104 Senior Geotechnical Engineer, Kleinfelder, 4835 Longley Lane, Reno, Nevada, 89502 [email protected]. 105 Principal Geotechnical Engineer, Kleinfelder, 1330 Broadway, Suite 1200, Oakland, California 94612, [email protected].

75 NOTES

76 IT IS SEEPAGE INDEED — A SENSITIVITY STUDY ON SEEPAGE AND SEEPAGE-INDUCED SLOPE STABILITY OF LEVEES

Khaled Chowdhury, PE, GE1 Richard Millet, PE, GE2 Sujan Punyamurthula, PhD., PE3 Gyeong-Taek Hong, PhD., PE4 Nichole Tollefson5

ABSTRACT

Typical failure modes observed in levees are caused by underseepage, through seepage, slope instability, erosion, and overtopping. Overtopping and erosion are strongly influenced by hydraulic conditions. For the remaining failure modes seepage is the major contributor to multiple types of distress conditions in a levee during flood events. Underseepage, which may cause piping and internal erosion of materials due to excessive pore water pressure under the blanket layers, also negatively impacts slope stability by reducing effective stresses in the foundation soils. Similarly, through seepage, which may cause removal of materials from levee embankments due to piping through non-cohesive soils, reduces the factor of safety against slope stability failure. Underseepage and through seepage are dependent on multiple factors that include net head, embankment and foundation stratigraphy, material types, levee geometry, hydraulic conductivity of the embankment, blanket, and aquifer, contrast between blanket and aquifer hydraulic conductivity, blanket thickness, and the presence or absence of a waterside blanket.

A sensitivity study was performed to evaluate different factors on steady state underseepage and through seepage conditions on levees, and subsequently, the effects on slope stability. The results of these seepage and stability studies were compared with current United States Army Corps of Engineers (USACE) criteria (EM 1110-2-1913). Different contributing factors were evaluated under both existing and remediated levee conditions. If a reduction in a slope stability factor of safety is driven by seepage conditions, seepage mitigation measures should also improve stability conditions. Sensitivity study results indicate that slope stability factors of safety vary significantly for a wide range of soil strength parameters as seepage conditions vary. However, this variation in slope stability factors of safety is significantly reduced in levee sections remediated for seepage conditions. Exceptions to these findings include levees founded on soft organic soils or fissured highly plastic clay, where stability of an existing levee is mainly dependent on the strengths of embankment and near surface foundation layers. Due to the findings that levee seepage characteristics affect the majority of levee failure modes (i.e. underseepage, through seepage, and seepage-induced slope stability conditions), data collection efforts should focus more on collecting information on factors that affect seepage conditions so that an effective mitigation measure can be designed.

1 Project Manager, URS Corporation, 2870 Gateway Oaks Ste 150, Sacramento CA 95833, [email protected] 2 Vice President, URS Corporation, Sacramento, CA , [email protected] 3 Vice President and A/E Division Manager, URS Corporation, Sacramento, CA, [email protected] 4 Senior Staff Engineer, URS Corporation, Sacramento, CA , [email protected] 5 Senior Staff Engineer, URS Corporation, Sacramento, CA , [email protected]

Slope Stability of Levees 659 NOTES

78 REACHING SETTLEMENTS: USING DESIGN MEDIATION TO RESOLVE SUBSURFACE CONFLICT BETWEEN FLEXIBLE AND RIGID FOUNDATIONS WITHIN LEVEE SYSTEM TRANSITION ZONES

Michael S. Quinn111 James J. Hance112 Richard J.Varuso113 Sean G.Walsh114

ABSTRACT

The Joint Venture design team recognized during the USACE Independent Technical Review (ITR) process that the transition from the proposed the T-wall section of the levee system to a proposed 16 feet high earthen levee required a detailed understanding of settlement response within this transition zone. The design review was preformed on two segments of the New Orleans West Bank and Vicinity (WBV) Hurricane Storm Damage Risk Reduction System (HSDRRS) where the estimated settlements made it clear that careful design consideration was imperative given the anticipated settlements of the pile supported T-wall monoliths were less than one inch, and settlements of the abutting earthen levee embankment were estimated in excess of several feet.

Ground improvement through preconsolidation of thick soft to very soft compressible silt and clay soils was selected for the transition zone where T-wall construction supported by deep pile foundation ends and earthen embankment placed on existing subgrade begins. Preconsolidation was achieved by the use of vertical and lateral drains (i.e., geosynthetic composite drains), a sand blanket drain at the surface and a designed pre- load soil mass. The preconsolidation of the transition zone addressed two significant design concerns: 1) Overstressing of steeply battered piles as a result of free field soil mass movement across the piles during consolidation; and 2) Large settlement beneath the T-wall bases, leading to separation and development of voids as the subgrade settles away from the pile supported base.

A geotechnical instrumentation plan was developed to monitor settlement and porewater pressure response within the foundation soils in response to preloading and evaluate when sufficient consolidation had been reached. This paper presents the data collected from the instrumentation which include vibrating wire settlement gauges and piezometers as well as standpipe settlement platforms and inclinometers.

Using the observed settlements, this paper presents an evaluation of battered pile bending stresses that were mitigated through pre-consolidation. Bending moments are estimated using the method developed by researchers at Virginia Tech and the USACE who were commissioned by the USACE to develop a practical, straightforward approach for engineering design of T-wall pile foundations using the computer program LPILEby Ensoft, Inc.

111 Principal Geotechnical Engineer, Malcolm Pirnie – ARCADIS, [email protected] 112 Vice President, Eustis Engineering Services, LLC., [email protected] 113 Deputy Chief, Geotechnical Branch,USACE-New Orleans District, [email protected] 114 Geotechnical Engineer, Malcolm Pirnie – ARCADIS, [email protected]

79 NOTES

80 PILE FOUNDATION DESIGN IN SOFT SOILS FOR THE WORLD’S LARGEST DRAINAGE PUMPING STATION

Kevin Zitzow, PE115

ABSTRACT

The design of the Gulf Intercoastal Waterway, West Closure Complex Pump Station included a pile foundation developed based on methods outlined in the USACE Engineering Manual 1110-2-2906 (1991) and the Hurricane Storm Damage Risk Reduction System Design Guidelines (July 2008). Design capacities based on these methods for deep foundations in soft soils were used in several iterations of the design. Pile load tests were conducted on test piles and production piles providing an opportunity to compare the design methods to the site test results. Methods used to develop design capacity curves from soil parameters are outlined and these theoretical capacities are compared with some of the values measured in the field, before and during construction of this massive project.

115 ARCADIS, 1210 Premier Drive, Suite 200, Chattanooga, TN 37421, [email protected]

81 NOTES

82 FULL-SCALE TESTING OF LEVEE RESILIENCY DURING WAVE OVERTOPPING

Christopher Thornton116 Bryan Scholl117 Steven Hughes118 Steven Abt119

ABSTRACT

Resilient levee design requires reliable guidelines that relate the performance of levee grass and armoring alternatives to expected wave overtopping hydrodynamic loads. This guidance can only be developed using controlled experiments conducted at full scale to avoid significant scale effects related to grass strength and soil erosion. Colorado State University was commissioned by the New Orleans District, Corps of Engineers to: (1) design, build, fabricate, and calibrate a large Wave Overtopping Simulator, and (2) conduct extensive resiliency tests of grass slopes and other erosion protection alternatives subjected to very high irregular wave overtopping rates. The landward-side levee slope was replicated for the experiments using “planter boxes” prepared in the same manner as actual levee slopes. The planter boxes were placed into the overtopping facility, and wave overtopping loading was applied at progressively higher discharge rates. The grass proved to be surprisingly resilient at average discharges up to 4 ft3/s per ft without failure, but dormant grass did fail at lower average discharge rates. Bare clay exhibited little resiliency to wave overtopping. This paper overviews the features and capability of the Wave Overtopping Test Facility; describes preparation of “planter trays” containing representative levee slope protection; and presents results from full-scale tests on healthy levee grass, dormant levee grass, bare clay, and articulated concrete block protection.

116 Director, Engineering Research Center, Colorado State University, USA. [email protected]. 117 PhD Candidate, Colorado State University, USA. [email protected]. 118 Senior Research Scientist, Colorado State University, USA. [email protected]. 119 Senior Research Scientist Scholar, Colorado State University, USA. [email protected].

83 NOTES

84 FLOOD PROTECTION FOR THE HENDERSON BAYOU WATERSHED

Stephen L. Whiteside, P.E.120 Nabil S. Mikhail, P.E., D.GE. 121 Richard L. Hoffer, P.E.122

ABSTRACT

The Henderson Bayou Watershed in Ascension Parish, Louisiana, includes the town of Galvez, Louisiana, and has an area of approximately 14 square miles. The main channel of Henderson Bayou begins near the intersection of Misty Oak Court and N. Burnside Avenue. It flows southeast until it crosses Henderson Bayou Road. From there, the channel flows northeast until it eventually discharges into the Amite River.

Flood management facilities were recommended in a preceding watershed study to protect against backwater flooding from the Amite River. That study showed major flooding within the Henderson Bayou Watershed resulting from backwater from the Amite River.

Based on the previously completed watershed hydrology report, and due to the various flooding sources, the focus was designing a flood protection structure for a 10-year Amite River backwater event. The proposed project includes flood gates to maintain the existing level of service within the watershed when the Amite River is under normal conditions. Because backwater events could potentially occur in conjunction with large storm events, the design includes a pump station to reduce the potential for flooding of structures within the watershed when all gates are closed.

This paper presents the final design and construction of the flood management facilities consisting of a proposed stormwater pump station, flood protection levee, and flood gate structure upstream of the Amite River confluence. The flood gate system consists of four bulkhead gates including one for the navigation channel to maintain navigation in the bayou. Also, the project includes a levee system that ties into the west side of the pump station/flood gate structure and extends in a westward direction in order to complete the backwater prevention protection system The system is currently under construction.

120 Vice President, CDM Smith, 5400 Glenwood Avenue, Suite 300, Raleigh, NC 27612, [email protected] 121 Senior Geotechnical Engineer, CDM Smith, 1515 Poydras Street, Suite 1350, New Orleans, LA 70112, [email protected] 122 Principal, CDM Smith, 1515 Poydras Street, Suite 1350, New Orleans, LA 70112, [email protected]

85 NOTES

86 WE DO NOT WANT THAT TO HAPPEN AT OUR WASTEWATER TREATMENT PLANT LEVEE!

Tyler C. Dunn, P.E.123 Stephen L. Whiteside, P.E.124 Michael P. Smith, E.I.T.125

ABSTRACT

CDM Smith was retained by the Narragansett Bay Commission (NBC) to perform a geotechnical evaluation to rehabilitate the flood protection levee at the Bucklin Point Wastewater Treatment Facility (BPWWTF) located in East Providence, Rhode Island. The facility was constructed in 1952 on a low-lying peninsula on the Seekonk River. In 1973, tidal flats were filled to expand the site and the flood protection levee was built around the perimeter of the expanded peninsula to protect the facility from a 100-year storm event. The levee consists of a 2,990-foot-long earthen embankment with heights ranging from 8 to 19 feet. Two stormwater drainage basins are located at the landside toe of the levee. At each stormwater drainage basin, a drain pipe passes under the levee to an outfall at the riverside toe.

In light of the March 2010 floods that overtopped a levee severely affecting another wastewater treatment plant, NBC decided to evaluate the condition of their levee. The project included a review of existing documents; performing a field inspection, topographic survey, and subsurface investigations; and conducting multiple analyses to evaluate the levee. Designed remedial repair alternatives were evaluated and contract documents were prepared for the rehabilitation of the levee. Improvements that will be made include raising the crest of the levee by approximately 3 feet, restoring and fortifying riverside slopes with riprap, and building out the landside slope. To maintain the storage volume of the two adjacent stormwater drainage basins, the improvements also include two gabion walls to support the added landside slope. Construction is planned to start in the first quarter of 2012.

123 Senior Geotechnical Engineer, CDM Smith, 50 Hampshire Street, Cambridge, MA 02139 [email protected] 124 Vice President, CDM Smith, 5400 Glenwood Avenue Suite 300, Raleigh, NC 27612 [email protected] 125 Geotechnical Engineer, CDM Smith, 50 Hampshire Street, Cambridge, MA 02139 [email protected]

87 NOTES

88 GEOPHYSICAL INVESTIGATIONS FOR LEVEE SYSTEMS — KILLING SEVERAL BIRDS WITH ONE STONE

Michael K. Sotak, P.E.126 Douglas E. Laymon, P.G.127 Thomas A. Chapel, P.G., P.E.3

ABSTRACT

Geophysical investigations can be an excellent tool for building the foundation of any new or existing levee system project. A wealth of data can be collected very quickly that can ultimately serve many purposes in the planning, design, and construction of levee embankments. In recent flooding along the Missouri River, we learned that the information obtained can be an excellent tool for anticipating and designing under- and through-seepage control measures in levees, thereby reducing the uncertainty during flood fighting events. Coupled with traditional geotechnical investigations (drillholes, corings, test pits), geophysical investigations can help to reduce overall project costs, both in the investigations themselves, and in the constructed project. This is accomplished by “filling in the gaps” in geotechnical investigations and reducing the unknowns and risks associated with the unknown during system design and analysis that can lead to higher construction costs. This paper addresses the geophysical investigations performed to date for one project near Omaha, Nebraska and how that will be coupled with future geotechnical investigations.

Along with aerial imagery and soil information, geophysical profiles can often help to reveal part of the geologic history of a levee system. A solid understanding of the geologic history affords the design team the ability to design the appropriate controls and appurtenances for levee systems that enhance the overall performance and reliability of the system by reducing uncertainty in the levee foundations. Included herein are examples from two projects how this “toolbox” approach can reduce risk for designers and levee owners.

Collectively, the cost savings, understanding and increased confidence that geophysical investigations offer to levee systems reduces both the risk and uncertainty in these systems and is therefore a tool that can benefit every levee system operator and owner. Some examples of cost savings are given herein and more are being developed as the project progresses.

126 Tetra Tech, 12120 Port Grace Blvd, Suite 102, Omaha, NE 68128, [email protected] 127 Tetra Tech, 7800 Shoal Creek Blvd, Ste 253E | Austin, TX 78757-1031, [email protected] 3 Tetra Tech, 3801 Automation Way, Suite 100, Fort Collins, CO 80525, [email protected]

89 NOTES

90 SUCTION AND MOVEMENT MONITORING OF LEVEES

Vishal Dantal128 Charles Aubeny129 Robert L. Lytton130

ABSTRACT

The failure mode for levees includes: excessive settlement, foundation failure, seepage due to cracking or piping and surface erosion. Cracks in levees induce excessive seepage rates across the section which results in failure of the levee during flooding periods. The current analysis for cracks or suction prediction is done using climatic variation for a given region. The climatic variation as an input makes the suction evaluation generalized and erases the local effect of soil conditions and overestimates the suction values. It estimates the suction in the absence of a water table. When a water table is present within 10 m of the surface, it becomes necessary to have the local reading of moisture content close to the site for predicting the suction values which are unique to the specific site conditions.

In this research, a two phase approach is taken. First the Ground Penetrating Radar (GPR) is used to measure the overall moisture variation along the levee to locate the possible crack zones. This will help in predicting cracks induced by the site specific suction values. After the critical sites have been identified they will be instrumented using moisture content sensor, tensiometers and tilt meter as a long term monitoring systems. This method will result in accurate estimation of impeding failure. This approach will also help in early warning systems by giving a realistic estimate of the health of the levee. The current work will help in reducing cost of inspection and maintenance, and will help to save valuable lives and resources.

128Doctoral Student, Zachry Department of Civil Engineering, Texas A&M University, College Station, TX 77843-3136. Ph.no: 9795712286. E-mail: [email protected]. 129Associate Professor, Zachry Department of Civil Engineering, Texas A&M University, College Station, TX 77843-3136. Ph.no: 9798454478. E-mail: [email protected] 130Professor, Zachry Department of Civil Engineering, Texas A&M University, College Station, TX 77843- 3136. Ph.no: 9798459964. E-mail: [email protected].

91 NOTES

92 ENHANCING EROSION RESISTANCE OF LEVEE BY GROUND MODIFICATION

James T. Kidd, EIT131 Chung R. Song132 Alexander H.-D. Cheng133 Wongil Jang134

ABSTRACT

Hurricane Katrina caused erosion of soils in New Orleans, and consequently the failure of several sections of floodwalls in New Orleans. This study evaluated the erosion mitigation techniques. The soil cement and geo-fibers were used as soil modifiers. And the erosion characteristics of modified soils were evaluated using University of Mississippi Erosion Testing Bed (UMETB). Test results showed that soil cement was effective in reducing erosion but the geo-fibers were not as good as soil cement.

131 AOS Research Group, Air Force Research Laboratory, Tyndall AFB, FL 132 Associate Professor, Department of Civil Engineering, University of Mississippi, [email protected] 133 Cheng, Professor and Dean, School of Engineering, University of Mississippi 134 Korea Land and Housing Corp.

93 NOTES

94 PROTECTING OUR NATIONAL HERITAGE — THE WASHINGTON, D.C., LEVEE

Pete Nix, P.E.135 Steven Riedy, P.E.136

ABSTRACT

The existing Potomac Park flood protection system was authorized by the Flood Control Act of 1936 following a devastating flood in March of that year. Construction was completed in 1940 and the system consists of an earthen berm that extends from the Lincoln Memorial on 23rd Street to the National Monument on 16th. The berm runs along the north side of the Reflecting Pool and has an opening at the roadway of 17th Street that can be closed using sand bags and an earthen berm.

The National Park Service and the Corps of Engineers – Baltimore District are upgrading the flood protection system for our Nation's capital. As part of the first phase of work, Tetra Tech designed and is providing construction support for a new closure structure at 17th Street. The new closure consists of a removable post and panel closure structure across the 17th Street and two permanent reinforced concrete floodwalls located outside the 17th Street right-of-way. The reinforced concrete floodwalls are veneered with stones that are compatible with the nearby existing structures and surrounding environmental settings.

The second phase of the project will consist of designing and constructing a new levee along 23rd Street at Constitution Avenue, raising the Reflecting Pool levee to withstand the project design flood, and designing and constructing a new closure alignment near Fort McNair on the south side of the City. Tetra Tech is currently designing this second phase of the project.

135 Senior Program Manager Tetra Tech, 6530 West Campus Oval, Suite 130, New Albany, OH 43054. 614-289-0117, [email protected] 136 Geotechnical/Civil Engineer Tetra Tech, 6530 West Campus Oval, Suite 130, New Albany, OH 43054, [email protected]

95 NOTES

96 BUILDING A LEVEE IN THE ALASKA WILDERNESS: BALANCING RISK, ROBUSTNESS, AND PROJECT COST

Matthew Redington, P.E.137 Glen Krogman, P.E.138

ABSTRACT

The Alaska Railroad Corporation (ARRC) is building an 80-mile extension of its existing main line track between Fairbanks and Delta Junction, AK. One of the project’s major features is a 3,300 foot long bridge across the Tanana River. Backwater effects from this bridge necessitate construction of a levee along the Tanana River upstream from the bridge. This levee will be 2 miles in length and will protect the riverside community of Salcha, AK.

The river experiences severe ice jams and flooding from spring mountain snowmelt, rains and glacier runoff. The Tanana is a dynamic river with braid configurations and channel bank locations that constantly change. The convergence of channel braids can create 50 foot deep scour holes. Channel bank undercutting into the mature Spruce tree forests that flank the river results in heavy debris conditions in the main channel. The presence of heavy debris loads, ice jams, and deep scour holes result in highly variable levee design conditions.

Careful evaluation of risk and robustness was an essential part of project design. Through the Contractor Manager General Contractor (CMGC) project delivery approach, a team was assembled including representatives of the owner, contractor and engineer to evaluate project risks and mitigate for those risks through refinements to design. Key refinements to the design included changes to levee stabilization design and levee alignment. The harsh conditions of the Alaska wilderness required a careful balance between risk, robustness of design, and economics. Total project costs were reduced as a result of identifying risks and reducing uncertainties.

137 Project Manager, HDR Engineering, Inc. 701 Xenia Avenue South, Suite 600, Minneapolis, MN 55416. [email protected] 138 Project Manager, HDR Alaska, Inc. 2525 C Street, Suite 305, Anchorage, AK 99503. [email protected]

97 NOTES

98 ADDRESSING DEFICIENCIES IN THE VENTURA RIVER LEVEE SYSTEM

Ike Pace, P.E.139 Michael E. Zeller, P.E. P.H., 2

ABSTRACT

Originally constructed in 1949 by the U.S. Army Corps of Engineers, the Ventura River 1 Levee System (VR-1) in Ventura County, California was an approximately 2.65-mile- long levee system placed along the bank of the Ventura River. The levee slope was protected with loose riprap revetment from the Pacific Ocean to river mile 0.92 then with grouted riprap revetment to the upstream limit.

In an August 31, 2007 letter to the Ventura County Watershed District (District), FEMA identified potential levees or levee-like situations in Ventura County which FEMA had reason to believe might provide base-level flood protection to the areas landward of such levees. FEMA’s letter provided the District with the opportunity to seek Provisionally Accredited Levee (PAL) designation status for some or all of those levees. After a period of negotiation with FEMA, the list was refined to nine (9) levees, including VR-1 levee, which the District would consider for potential certification pursuant to 44 CFR 65.10. Tetra Tech, on November 25th 2008, was contracted by The District, to perform the analysis for the PAL certification in order to meet the November 30, 2009 deadline date for the submission of levee documentation packages to FEMA. In an evaluation report dated February 20, 2011, Tetra Tech determined that the VR-1 levee could not be certified without rehabilitation of the system. With the PAL timeline expired, FEMA is in the process of revising their mapping to reflect de-accreditation of this levee.

The District is pursuing options with the U.S. Army Corps of Engineers to fully assess the conditions (existing and future) and rehabilitate the levee. A Feasibility Study or a Design Deficiency Study is being considered as likely routes to accomplish this work.

139 Ike Pace, P.E., Principal Program Manager 17885 Von Karman Avenue, Irvine, 92614, [email protected] 2 Michael E. Zeller, P.E., P.H., Principal Water Resources Engineer 4801 East Broadway Blvd., Tucson, AZ 85711, [email protected]

99 NOTES

100 SUSTAINABLE DESIGN FOR THE SOLDIER CREEK LEVEE REPAIR

John Ruhl140 Seth Laliberty141

ABSTRACT

The Soldier Creek Diversion Unit Repair Project represents the latest USACE Kansas City District investment in sustainable water infrastructure. Soldier Creek crosses the north side of the City of Topeka, Kansas through a partially developed floodplain of the Kansas River. The diversion unit, constructed in the 1950s, consists of eighteen miles of earthen levee, nine miles of improved channel, and thirty-five drainage structures. The 1950’s channelization project significantly changed the planform of the channel and induced substantial changes in profile.

The instabilities identified today may be derived from the steep banks that resulted from these drops in channel elevation. The existing slope of the channel bed continues to amplify the rate of degradation, being steeper than the equilibrium slope, given the existing channel bed materials. In October 2005, the levee was overtopped and the diversion unit seriously damaged. Black & Veatch prepared a conceptual design for the repair using the Soar & Thorne approach and HEC-RAS to evaluate any changes in water surface profiles, stream velocities, and energy gradelines. The design features included rock checks to maintain bed elevation, vegetation to augment stability, and a meandering low flow channel within the levee system.

Construction has been on-going since November 2009. A variety of construction challenges have arisen including unexpected utilities, differing geotechnical conditions from those expected, plant establishment, and high water events. Construction completion is expected late this year or early in 2012.

140 Black & Veatch, 6601 College Blvd., Overland Park, KS, [email protected] 141 Corps of Engineers, Kansas City District, 601 East 12th Street, Kansas City, MO, [email protected].

101 NOTES

102 USSD GUIDELINES FOR DAM DECOMMISSIONING PROJECTS, EXECUTIVE SUMMARY

Timothy J. Randle142 Thomas E. Hepler143

ABSTRACT

Dam removal is becoming more common in the United States as dams age and environmental concerns increase. The USSD Dam Decommissioning Committee has produced a new document entitled: Guidelines for Dam Decommissioning Projects. The primary objective of these guidelines is to provide dam owners, dam engineers, and other professionals with the information necessary to help guide decision-making when considering dam decommissioning as a project alternative. This document has chapters on the following topics: • Factors to consider for decommissioning a dam • Project planning and decision making • Design process • Sediment management • Construction activities • Performance monitoring and mitigation

In addition to these important topics, the Guidelines provide links to many case studies.

142 Supervisory Hydraulic Engineer, Bureau of Reclamation, Denver, Colorado, [email protected]. 143 Civil Engineer and Technical Specialist, Bureau of Reclamation, Denver, Colorado, [email protected].

103 NOTES

104 ELWHA RIVER RESTORATION: SEDIMENT MANAGEMENT

Timothy J. Randle144 Jennifer A. Bountry145

ABSTRACT

The National Park Service, with technical support from the Bureau of Reclamation, is in the process of removing Elwha and Glines Canyon Dams on the Elwha River near Port Angeles, Washington to restore anadromous fish and the natural ecosystem. Elwha Dam was completed in 1913 and forms Lake Aldwell. Glines Canyon Dam was completed upstream in 1927 and forms Lake Mills. These two dams are the largest ever removed. These dams are being removed concurrently in controlled increments over a three-year period, which began on September 17, 2011. As of July 2010, reservoir sedimentation for the two lakes was estimated to be 24 million yd3, of which 20 million yd3 are stored in Lake Mills.

Facilities have been constructed for water quality and flood protection, including water treatment plants, new wells, a new surface water intake, raising the height of existing levees, and the construction of new levees. A monitoring plan is presently being implemented to compare measured effects with predictions and take corrective actions if necessary. Early monitoring results confirm that lowering the reservoir pool in a controlled increment, and then holding the reservoir pool at constant elevation, is inducing vertical and lateral erosion of the exposed delta surface. Coarse sediments eroded from the exposed delta are re-deposited across the width of the receded reservoir. Eroded fine sediments become suspended in the reservoir and a portion of them are passing downstream of the dam.

144 Supervisory Hydraulic Engineer, U.S. Bureau of Reclamation, Denver, Colorado, [email protected]. 145 Hydraulic Engineer, U.S. Bureau of Reclamation, Denver, Colorado, [email protected].

105 NOTES

106 DETAILED PLAN FOR POTENTIAL REMOVAL OF KLAMATH RIVER HYDROELECTRIC FACILITIES

Tom Hepler, P.E.146 Blair Greimann, P.E.147

ABSTRACT

Feasibility-level studies have been performed for removal of four hydroelectric dams on the Klamath River in Oregon and California, to provide a free flowing condition and volitional fish passage to an estimated 68 miles of coho salmon habitat and 420 miles of steelhead habitat in the upper Klamath River basin. Numerous engineering reports and environmental documents have been prepared to allow the Secretary of the Interior to determine whether the removal in 2020 of all or part of each of the hydroelectric facilities would (a) advance restoration of the salmonid fisheries of the Klamath Basin, (b) be in the public interest, and (c) not exceed $450 million, which is the total amount to be provided by Oregon and California. This paper addresses the physical methods and timetable necessary for dam removal; plans for management, removal, and/or disposal of reservoir sediment; plans for site restoration and potential impact mitigation; and estimated project costs, as provided in the Detailed Plan (Reclamation, 2011b).

146 Technical Specialist, Bureau of Reclamation, P.O. Box 25007, Denver CO 80225, [email protected] 147 Hydraulic Engineer, Bureau of Reclamation, P.O. Box 25007, Denver CO 80225, [email protected]

107 NOTES

108 MODELING CHANNEL FORMATION ON THE KLAMATH RIVER DUE TO RESERVOIR DRAWDOWN

Yong G. Lai148 Blair P. Greimann149

ABSTRACT

Four dams - JC Boyle, Copco 1, Copco 2, and Iron Gate - on the Klamath River in Oregon and California are under consideration for possible decommissioning. Copco 2 dam is proposed to be removed first as it contains negligible sediment deposits. A concurrent drawdown of the remaining three reservoirs (JC Boyle, Copco1, and Iron Gate) and subsequent removal are proposed to follow. There are about 10 million cubic meters of deposits stored within these reservoirs that consist of mostly high water content silt and clay. Drawdown of the reservoir is expected to cause erosion of a significant portion of this sediment and the specific dam decommissioning plan chosen would try to limit the negative consequences of this sediment release. The erosion and deposition pattern upstream would also impact the strategy of how to restore a functional riparian corridor.

In this study, the channel formation process due to drawdown of Copco 1 Reservoir is investigated using a two-dimensional flow and mobile-bed model, SRH-2D. Copco 1 Reservoir is selected since it contains the largest portion of the reservoir deposits and may have the largest impact due to many nearby residences. The channel form resulting from drawdown is predicted, as well as the areas of deposition. These model results provide a basis in determining the best strategy for revegetating the reservoir area and recovering a functional riparian corridor. The model also determines the amount of sediment released downstream under different drawdown scenarios so that impacts from high suspended sediment concentration may be compared and assessed. The results aid in determining the timing, duration, and rate of drawdown

148 Technical Service Center, US Bureau of Reclamation, Denver, CO; (303) 445-2560; [email protected] 149 Technical Service Center, US Bureau of Reclamation, Denver, CO; (303) 445- 2560;[email protected]

109 NOTES

110 PRESERVING REGULATED RIVERS BY OPTIMIZING HYDROELECTRIC DAM OPERATIONS

Brent Travis150

ABSTRACT

Fluctuating flow releases on regulated rivers destabilize downstream riverbanks, causing unintended, unnatural, and uncontrolled geomorphologic changes. These flow releases, usually a result of upstream hydroelectric dam operations, create manmade tidal effects that cause significant environmental damage; harm fish, vegetation, mammal, and avian habitats; and destroy riverbank camping and boating areas.

For regulated rivers downstream of hydroelectric dams, bank failures can often be reduced, but not eliminated, by modifying flow release schedules. Typically, comprehensive mitigation can only be accomplished with expensive rebuilding floods which release trapped sediment back into the river.

Here, a simulated annealing scheme is presented to optimize weekly hydroelectric dam releases in order to minimize the cost of annually mitigating downstream bank failures. A full array of constraints is considered, including physical, environmental, mechanical, operations, and flow factors. The general procedure is presented, and an example application is given utilizing a recently developed comprehensive risk model for bank failures along the Colorado River in the Grand Canyon. A solution is obtained that mitigates downstream failure risk, allows annual rebuilding floods, and predicts a hydroelectric revenue increase of more than 2%.

150 Senior Hydraulic Engineer, WEST Consultants, Inc., 8950 South 52nd Street, Suite 210, Tempe, AZ 85284-1043, [email protected]

111 NOTES

112 RESERVOIR OPERATIONS FOR TROUT SURVIVAL ALONG THE WHITE RIVER

Kevin Fagot, P.E.151 Mike Biggs, P.E.152

ABSTRACT

The White River consists of five high head dams located in northern and central Arkansas as well as in southern Missouri. These projects include Beaver, Table Rock, Bull Shoals, Norfork, and Greers Ferry. Due to the coldwater releases from these dams, the impact to the smallmouth bass fishery was mitigated through the introduction of a trout fishery. Below these five dams, approximately 150 miles of cold water environment for trout exists. This trout fishery provides great economic benefit to the region and produced a world record brown trout on the Little Red River in 1992. This trout fishery is maintained by three fish hatcheries located at Table Rock, Norfork, and Greers Ferry. This paper will explore the operational efforts that are conducted by the Little Rock District of the U.S. Army Corps of Engineers to ensure that the necessary dissolved oxygen and temperature requirements are met to ensure the survival of this fishery.

151 Project Manager, WEST Consultants, Bellevue, WA, [email protected] 152 Chief, Reservoir Control, U.S. Army Corps of Engineers, Little Rock District, [email protected]

113 NOTES

114 DELIVERING THE ABBERTON SCHEME, AN ENHANCED WATER RESOURCE FOR SOUTH-EAST ENGLAND

Jonathan Troke153 Jim Jenkins154 Ian Carter155 David Knott156

ABSTRACT

The Abberton Scheme is a £150M water resources scheme in the south-east of England being undertaken by Essex & Suffolk Water Company to provide additional water for the Essex Supply Area and Greater London. The scheme comprises the raising of Abberton Reservoir and the uprating of the existing Ely-Ouse to Essex Transfer Scheme that transfers water from Norfolk to Essex, thus increasing the availability of pumped inflows to the reservoir. It is the first of an expected programme of water resource schemes to meet the predicted shortfall in supply to the south east of England. With a project life approaching 20 years, this paper describes how the scheme has been delivered to date, including the promotion and stakeholder engagement process and the engineering design and procurement. The paper places a particular focus on the works at the reservoir to increase storage and improve the habitat for wild fowl. Construction of the Abberton Scheme commenced in December 2009 and is scheduled for completion in April 2013.

153 Project Engineer, MWH, Terriers House, 201 Amersham Road, High Wycombe, Bucks, HP13 5AJ [email protected] 154 Abberton Programme Manager, Essex & Suffolk Water, Sandon Valley House, West Hanningfield, CM3 8BD 155 All Reservoirs Panel Engineer, MWH, Terriers House, 201 Amersham Road, High Wycombe, Bucks, HP13 5AJ 156 Project Manager, MWH, Terriers House, 201 Amersham Road, High Wycombe, Bucks, HP13 5AJ [email protected]

115 NOTES

116 LOUISIANA DOTD RESERVOIR PRIORITY DEVELOPMENT PROGRAM

William F. McHie, P.E.157 William R. Swanson158 Zahir (Bo) Bolourchi, P.E.159

ABSTRACT

Water, both above and below ground, is Louisiana's most abundant resource. Louisianans recognize the importance of sustainable water resource management to support healthy ecosystems and promote thriving economies. In the recent past, some consequences of water resources development have begun to appear in locations around the state, as evident in low surface water flows, impaired surface water quality, groundwater level decline, and degraded groundwater quality. To encourage projects that will address these issues and promote sustainable economic development, the Louisiana Department of Transportation and Development (DOTD) Public Works and Water Resources Division was directed by the Legislature to establish a Reservoir Priority and Development Program (RPDP).

The RPDP establishes procedures to submit and evaluate applications for proposed state- funded reservoir projects (based on a comprehensive suite of engineering, environmental and socioeconomic criteria) and provide a list of ranked projects to the Legislature for funding based on the best value for the state. To support evaluation criteria and funding decisions, the RPDP provides information about statewide water resource issues relative to available water, future demands, and relevant environmental and socioeconomic issues. The RPDP also provides recommendations for a statewide water resources management strategy.

157 Vice President and Senior Project Manager, MWH Americas, Inc, 7742 Office Park Blvd, Ste. C-2, Baton Rouge, LA 70809; [email protected] 158 Vice President and Director of Technology, MWH Americas, Inc., 2121 N. California Blvd., Ste. 600, Walnut Creek, CA 94596; [email protected] 159 Director, P.W. and Water Resources Programs, Louisiana Department of Transportation and Development, P.O. Box 94245, Baton Rouge, LA 70809-9245, [email protected]

117 NOTES

118 SCRIPTING OF RULES IN HEC-RESSIM FOR THE ACF AND ACT BASINS

Kevin Fagot, P.E.160 Andy Ashley, P.E.161 James Hathorn, Jr.162 Joan Klipsch163 Henry Hu, PhD, P.E.164 Dan Eggers, P.E.165

ABSTRACT The U.S. Army Corps of Engineers (USACE) reservoir simulation software, HEC- ResSim, was used to model both the ACF and ACT river systems. Both of these systems are operated by USACE, Mobile District. The ACT and ACF were modeled for the updating of water control manuals, while the ACF system was additionally modeled as part of the implementation of the Corps Water Management System (CWMS). The ACT basin consists of the Alabama, Coosa, and Tallapoosa Rivers and drains approximately 22,800 mi2 in Georgia, Tennessee, and Alabama. There were 17 projects modeled in the HEC-ResSim model of the ACT. The ACF basin consists of the Apalachicola, Chattahoochee, and Flint Rivers and drains approximately 19,600 mi2 in Georgia, Alabama, and Florida. There were 10 projects modeled in the HEC-ResSim model of the ACF. Due to the complexity of these systems, the basic rules such as minimum and maximum releases, rate of change, and downstream control functions were inadequate to fully replicate the operation of these systems. This paper will detail the development and use of some of the state variables and scripted rules needed to reflect the real time operation of these systems.

160 Project Manager, WEST Consultants, Bellevue, WA, [email protected] 161 Chief, Hydraulics and Hydrology Branch, U.S. Army Corps of Engineers, Savannah District, [email protected] 162 Hydraulic Engineer, U.S. Army Corps of Engineers, Mobile District, [email protected] 163 Hydraulic Engineer, U.S. Army Corps of Engineers, Hydrologic Engineering Center, [email protected] 164 Project Manager, WEST Consultants, Bellevue, WA, [email protected] 165 Senior Engineer, WEST Consultants, Bellevue, WA, [email protected]

119 NOTES

120 SUSTAINABILITY OF HISTORIC WATER RESOURCE PROJECTS AFFECTING THE NATIONAL PARK SYSTEM

Charles Karpowicz 166

ABSTRACT

This paper is a general survey of four historic National Park Service (NPS) water resource projects recently modified, underway, or planned. These projects are in various natural, suburban, or urban national park unit settings and are critical in protecting life, property, natural resources, and/or maintaining project purposes.

They are as follows:

Rock Creek Park, Washington, DC: “Removing Barriers to Restore Fish Populations” which included a fish ladder being installed at the historic Peirce Mill Dam. The dam dates back to the early 1800’s and is still being used. Status: Modifications completed in 2007.

National Mall, Washington, DC: “West Potomac Park Levee Emergency Closure Modification”. Status: Original project completed in 1938 and modification is currently underway.

Chesapeake and Ohio Canal National Historic Park, DC, MD, WV: “1830’s Historic Mary’s Canal Wall Stabilization” Great Falls Tavern, MD. Status: Historic preservation stabilization ongoing.

“1834 Historic Dams No. 4 & 5 Eelway Passage Projects” Williamsport, MD. Status: Planning stage.

A standardized project data sheet is provided for each project with photographs and text.

166 Professional Engineer, Safety of Dams Engineer, Retired National Park Service and U.S. Army Corps of Engineers Dams Programs, Water Resources Management, Fairfax Station, VA 22039, [email protected]

121 NOTES

122 ASSESSMENT OF THE FLOOD VULNERABILITY OF DAMS DUE TO CLIMATE CHANGE IN SOUTH KOREA

Soo Jun Kim167 Hung Soo Kim168 Jong So Lee169 Hui Seong Noh170 Kyung Seok Kang171

ABSTRACT

Due to monsoons and tropical cyclones, more than two-thirds of the total annual precipitation falls during the summer rainy season of June to August in Korea. In addition, the geographical features of Korea produce relatively high peak flood discharge in conjunction with short duration rainfall events. This situation is getting worse as climate change becomes severe having a significant impact on flood control in Korea. In this study, a flood control vulnerability analysis that considers climate change is performed. The Han River Basin, located in the center of the Korean Peninsula, accounts for 23% of the territory of the Republic of Korea and is the country’s largest river basin, with an area of 23,000 km2. Within the basin, several multi-purpose dams are operated to reduce the risk of flood damage. We explored the effects of these dams on flood control considering different climate change scenarios. For the scenarios developed, runoff events are simulated by HEC-HMS based on the rainfall obtained under climate change. Finally, a comparison between the current flood control capacity of the dams in the Han River Basin and future flood capacity, obtained from the results of the simulation, was made to assess the vulnerability of flood control provided by multi-purpose dams considering these possible climate change scenarios.

167 Post-doctoral Researcher, Dept. of Earth and Environmental Engineering, Columbia University, US (e- mail: [email protected]) 168 Professor, Dept. of Civil Engineering, Inha University, Korea (e-mail: [email protected]) 169 Ph. D. Candidate, Dept. of Civil Engineering, Inha University, Korea (e-mail: [email protected]) 170 Ph. D. Candidate, Dept. of Civil Engineering, Inha University, Korea (e-mail: [email protected]) 171 Managing Director, Dept. of Water Resources, PEC (Pyunghwa Engineering Consultants Ltd), Korea (e-mail: [email protected])

123 NOTES

124 ROANOKE RAPIDS DAM — ADDRESSING CONCRETE DETERIORATION ISSUES

Matthew Pauvlinch172

ABSTRACT

Constructed in 1955, Roanoke Rapids Dam is a 72-foot-high, 3,050-foot-long concrete gravity dam with four 26-MW power generating units located on the Roanoke River in North Carolina. It is classified as a “high hazard” dam under the Federal Energy Regulatory Commission (FERC) guidelines by virtue of the potential loss of life and extensive property damage expected should the dam fail.

In the mid-1990’s, instrumentation at the South Non-Overflow Section (SNOS) began to indicate significant changes, including a steady increase in downstream movement. In 2003, there was little to no seepage/leakage discharge from the gallery entrance; however, leakage increased to over 100 gallons per minute by 2006.

Further investigation revealed long-term alkali-silica reaction (ASR) was occurring, which resulted in expansion of the concrete and cracking of the structure. The owner retained a commercial diving contractor to map the cracking on the upstream face of the SNOS. The inspection confirmed a crack extending from Block S3 to Block S8 with a maximum width of one inch and an offset of up to one inch.

The objective became the development of a remediation system to provide for future stability of Roanoke Rapids Dam during a probable maximum flood (PMF) event. The design also needed to recognize and accommodate the future effects of ASR expansion.

Ultimately, the plan comprised two components: grouting the existing cracks along the face of the SNOS and installation of 33 post-tensioned anchors. The crack required stabilization before anchor installation to avoid “breaking the back” of the dam, by possible closure of the crack during tensioning of the anchors. Therefore, the grout repair work was completed prior to anchor installation.

172 Project Manager, Brayman Construction, [email protected]

125 NOTES

126 ROCK STABILIZATION TO FACILITATE REPAIR OF THE HISTORIC OCOEE NO. 2 HYDRO-ELECTRIC PROJECT

Lindsay Cooper, P.G.173

ABSTRACT

The Ocoee No. 2 Project is a hydroelectric facility constructed by the Eastern Tennessee Power Company in 1913. Engineered by W.P. Creager, unique features of the Ocoee No. 2 Project are the 4.5-mile-long flume and siphon spillway which was the largest of its type in the world. The project was purchased by the Tennessee Valley Authority (TVA) in 1939, became a historic land mark in 1979 and may be the last surviving example of such a large scale development. The diversion dam was treated with roller compacted concrete (RCC), making the project the first ever use of RCC for over-topping protection.

Constructed in the mountainous terrain of Appalachia, rockslides are a constant threat. A rockslide occurred in April 2010 destroying approximately 70 feet of flume. During rehabilitation, three primary hazards at the site included unstable rocks along the surface of the upper slope, an unsettled debris pile, and a damaged flume foundation. A rock stabilization program was developed for the upper slope to minimize hazards during flume repairs. The rock stabilization consisted of scaling and rock bolting.

Rock bolt drilling revealed a system of interconnected voids. Subsequent investigations provided evidence of potential failure planes within the rock mass which required additional rock bolts and a phased approach to the debris pile excavation. This approach stabilized the rock mass across the deeper-seated discontinuities while taking advantage of the potential stability added by the debris pile. Debris removal exposed fractured and loose rocks all along the outer edge of the flume foundation. Subsurface exploration elevated concerns of foundation stability. Additional rock bolting was performed to stabilize the lower bluff and reinforce the foundation of the flume.

173 Staff Geologist, ARCADIS, 1210 Premier Drive, Chattanooga, Tennessee, 423-756-7193, [email protected].

127 NOTES

128 THE THIRD TIME’S A CHARM

Victor M. Vasquez, P.E.174 M. Leslie Boyd, P.E. 175 John L. Rutledge, P.E.176 Martin J. Cristofaro, P.E.177 Donald A. Bruce, Ph.D., C.Eng.178 Patrick Carr, P.E.179

ABSTRACT

The City of San Antonio has suffered from numerous floods on the San Antonio River throughout its history. In response to major floods in 1913 and 1921, the City implemented a flood control improvements program. Olmos Dam, finished in 1929 and located six miles north of downtown, was built as a flood retarding concrete gravity dam with no emergency spillway. Flood releases were made through six outlet tunnels regulated by slide gates. In 1974, an engineering study indicated that the dam did not have sufficient discharge capacity to prevent overtopping at PMF and the structure did not meet acceptable safety factors for events larger than the 100-year flood. As a result, modifications began in 1978 to replace 1,500 feet of the non-overflow section with an uncontrolled spillway and to add post-tensioned anchors to the non-overflow sections. As early as 1984, problems were reported with some of the bar anchors. In 1995, post- tensioned strand anchors were added to a select area of the dam to again increase its resistance to sliding and overturning. Subsequent inspection and testing of the anchors at Olmos Dam demonstrated a progressive deterioration of the anchors and a reduction in their capacity to hold the required load. Thus, in 2007 Bexar County embarked on a study to evaluate alternatives to stabilize Olmos Dam. Several alternatives were considered for stabilizing the dam in addition to strand anchors. However, strand anchors were far more cost effective in the final analysis and would have little or no effect on the historic appearance of the dam. Thus, Olmos Dam headed into its third round of anchors.

174 Freese and Nichols, Inc., 10814 Jollyville Rd., Building 4, Suite 100, Austin, TX 78759, (512) 617- 3142, [email protected] 175 Freese and Nichols, Inc., 10814 Jollyville Rd., Building 4, Suite 100, Austin, TX 78759, (512) 617- 3118, [email protected] 176 Freese and Nichols, Inc., 4055 International Plaza, Suite 200, Fort Worth, TX 76109, (817) 735-7284, [email protected] 177 AECOM, 6800 Park Ten Blvd, Suite 180S, San Antonio, TX 78213, (210) 296-2000, [email protected] 178 GEOSYSTEMS, L.P., 161 Bittersweet Circle, Venetia, PA, 15367, (724) 942-0570, [email protected] 179 Judy Company, Inc., 8334 Ruby Avenue, Kansas City, KS, 66111, (913) 422-5088, [email protected]

129 NOTES

130 DESIGN OF EMERGENCY WATER SUPPLY LINE TUNNEL AT WARM SPRINGS DAM

Sam Yao, PhD, PE180 Hugh Caspe, PE181 Michael O’Hagan, PE182

ABSTRACT

The Warm Springs Dam, measuring 319 feet high and 3,000 feet long, was completed in 1983 for the purposes of flood control, water supply, and recreation. The fish hatchery at Warm Springs was constructed to mitigate for the loss of upstream spawning and rearing habitat of salmon by the construction and operation of the dam. After the designation of Coho Salmon as federally threatened in 1995, US Army Corps of Engineers (USACE) expanded hatchery operations with the Coho Salmon Rescue Program. Consequently, the existing emergency water supply line can no longer meet the hatchery’s full demand for water. A new Emergency Water Supply Line, up to a supply capacity of 283 cubic feet per second, is being planned and designed to tap water from Lake Sonoma for the fish hatchery and downstream habitat. After completing an engineering evaluation of various alternatives, USACE decided to focus the design efforts on the tunnel options. This alternative consists of an approximately 3,000 feet long carrier tunnel constructed through the left abutment of the dam, tapping the existing wet well in the control structure. At the downstream end of the proposed carrier tunnel, the water supply pipeline continues as a buried pipe to connect to a stilling well structure, where the water is diverted to the fish hatchery. This alternative requires a water control design at the stilling well end to divert and/or split the flow. The tunnel water supply system is gravity fed with no pumps.

180 Ben C. Gerwick, Inc., 1300 Clay Street, 7th Floor, Oakland, CA 94804, (510) 267-7139, [email protected] 181 HNTB Corporation, Inc., 31 St. James Avenue, Boston, MA 02116, (617) 532-2290, [email protected] 182 HNTB Corporation, Inc., 1508 Eureka Road, Suite 130, Roseville, CA 95661, (916) 380-3983, [email protected]

131 NOTES

132 SAN VICENTE DAM RAISE PROJECT — TENSILE STRENGTH TESTING ON EXISTING DAM AND TRIAL PLACEMENT

183 Michel Jubran 184 Jim Zhou 185 Russ Grant 186 James Stiady 187 Andrew Oleksyn

ABSTRACT

The San Diego County Water Authority (Water Authority) is a public agency that imports up to 80 percent of the region’s water supply. The pipelines conveying imported water to the region cross several major fault lines. In 1998, the Water Authority approved a $1.5 billion Emergency Storage Project (ESP) to increase local storage and provide a more flexible conveyance system. The San Vicente Dam Raise (SVDR) project is a major component of the last phase of the ESP and consists of raising the existing 220-foot-high dam by 117 feet to increase reservoir storage capacity by 152,000 acre-feet. The raised San Vicente Dam will be about 337 feet high, creating an approximately 247,000 acre- foot reservoir. The dam raise is being constructed using roller compacted concrete (RCC). A saddle dam about 700 feet west of the main dam is also to be built using RCC. The saddle dam will be approximately 660 feet long and have a maximum height of about 45 feet above the foundation. The objective of the RCC for the San Vicente dam buttress and raise is to achieve strength and thermal properties of the RCC similar to those in the existing dam.

A full scale RCC trial placement was constructed using the same aggregate used to construct the existing concrete dam. Several 6-inch-diameter cores were extracted for direct tensile and unconfined compression strength testing. This paper presents the results of that coring program and how these results were used to confirm the RCC mix design for construction.

183 Design Resident Engineer, Montgomery Watson Harza, 9444 Farnham Street, San Diego, CA, [email protected]. 184 Design Manager, San Diego County Water Authority, 4677 Overland Avenue, San Diego, California 92123-1233. [email protected]. 185 Lab Manager, Klienfelder, 611 Corporate Circle, Suite C, Golden, Colorado, 80401, [email protected]. 186 QC Manager, G2D Resources, LLC, 7966 Arjons Drive, Suite 204, San Diego, CA 92126, [email protected]. 187 Construction Administrator, San Diego County Water Authority, 4677 Overland Avenue, San Diego, California 92123-1233. [email protected].

133 NOTES

134 PARTIAL DEMOLITION AND SURFACE PREPARATION OF EXISTING SAN VICENTE DAM

Eric Sturtz, P.E.188 Nick Patch189 Wayne Younger190 Jerry E. Reed III P.E191 Gary Olvera192

ABSTRACT

The San Diego County Water Authority (Water Authority) is currently undertaking the raise of the existing San Vicente Dam to provide both emergency and carryover storage to increase local reservoir supplies in San Diego County, California. The San Vicente Dam is part of the $1.5 billion Emergency Storage Project (ESP) and Carryover Storage Project (CSP) which will provide a more flexible conveyance system, and increase water supply reliability in case of catastrophic failure to the delivery system due to a major earthquake. The San Vicente Dam Raise (SVDR) project is a major component of the last phase of the ESP and consists of raising the existing 220-foot high gravity dam with 90,063 acre-feet of storage, by 117-feet to increase reservoir storage capacity by 152,000 acre-feet. Scheduled to be completed in 2013, the SVDR will be the tallest dam raise in the United States and tallest roller compacted concrete (RCC) dam raise in the world. The reservoir capacity will be more than doubled, making it the largest single increase in water storage in this region’s history.

Proper preparation of the expanded foundation, and existing San Vicente dam face, was critical for proper bonding and adhesion at the contact point between the existing dam downstream face and the new RCC dam. This paper will present the unique construction, scheduling, and coordination processes associated with preparing the existing concrete dam surface using hydro-demolition techniques to provide a sound contact-surface free of micro fissures and debris to bond with the new RCC dam on the downstream face, and preparation of the foundation under the footprint for the planned raised dam. Additionally, numerous existing dam features such as the dam crest, spillway ogee crest, parapet walls, spillway guide walls, flip bucket, stairways, and landings required demolition using conventional methods in preparation for the new RCC dam.

188 Resident Engineer, Black & Veatch Corporation, 300 Rancheros Drive, Suite 250, San Marcos, CA 92069, (760) 613-4503, Email: [email protected]; [email protected] 189 Project Manager, Barnard Construction Company, Inc, 701 Gold Avenue, Bozeman, MT 59771, (406) 586-1995, Email: [email protected] 190 Project Engineer, American Hydro Corporation, 9209 Philadelphia Road, Baltimore, MD 21237, (410) 574-8470, Email: [email protected] 191 Engineering Manager, , San Diego County Water Authority, 4677 Overland Avenue, San Diego, CA 92123, (858) 522-6835, Email: [email protected] 192 Construction Manager, San Diego County Water Authority, 4677 Overland Avenue, San Diego, CA 92123, (760) 535-3770, Email: [email protected]

135 NOTES

136 THE BENEFICIAL BEHAVIORAL CHARACTERISTICS OF FLY ASH-RICH RCC ILLUSTRATED THROUGH CHANGUINOLA 1 ARCH/GRAVITY DAM

Dr Quentin Shaw193

ABSTRACT

Recent research by the author focusing on four prototype dams identified a stress relaxation behavior during the hydration process in high cementitious, fly ash-rich RCC that is quite different to that of conventional mass concrete and low strength RCC and gives rise to specific benefits for the use of RCC in arch dams.

In this paper, the author discusses the findings of this research and illustrates the consequential impacts on RCC dam design and the specific benefits developed for RCC arch and arch/gravity dams. The innovations in dam design consequently made possible are illustrated through a description of the design and early performance monitoring of the 105 metre Changuinola 1 RCC arch/gravity Dam in northern Panama, which is the first RCC arch/gravity dam to be brought into service outside China and South Africa. With the last of the 900,000 m3 of RCC at Changuinola 1 Dam placed on 26th April 2011, the dam had filled to capacity and first spilled on 25th June 2011.

193 Director, Dams & Hydropower: ARQ (PTY) Ltd, Pretoria, South Africa

137 NOTES

138 CONSTRUCTION OF A 100-FOOT DEEP COFFERDAM IN THE OHIO RIVER

W. James Marold, PE194

ABSTRACT

The American Municipal Power, Inc. (AMP) is in the process of planning, design and construction of six new hydroelectric projects adjacent to existing USACE Locks and Dams on the Ohio River. The projects will deliver about 300 Megawatts of new power to the grid in the Ohio River Valley. Four of the projects are now under construction with two others in licensing applications. The four projects under construction are at Locks and Dams at Smithland, Cannelton, and Meldahl all in Kentucky and Willow Island in West Virginia.

The Cannelton Hydroelectric project was the first to acquire licensing. This paper describes the construction of the cofferdam that was built to facilitate construction of Cannelton Hydroelectric project. The cofferdam was completed in September 2010. The cofferdam for the Cannelton Hydroelectric Project was constructed on the Kentucky side of the Ohio River just west of the Domtar Paper plant and about 5 miles upstream of Hawesville, Kentucky. AMP awarded the cofferdam and powerhouse excavation construction contract to Kiewit Traylor Constructors – A Joint Venture (KTC) on February 7, 2009. The project was a design-build contract with Mueser Rutledge Consulting Engineers (MRCE) preparing the detailed cofferdam design and KTC carrying out the construction.

This paper describes the construction of the cofferdam on land and in the Ohio River, the means and methods including the up to 137 foot deep cement-bentonite slurry wall to top of bedrock, rock fill placement in the river to form the Marine dike, vibrocompaction of sand fill material within the rock fill dikes, earthfill, excavation, and emergency flood gate structure. Installation of deep dewatering wells, piezometers, inclinometers and monitoring points is also discussed. Lessons learned include measures taken during the Ohio River flood occurrence in December, 2009.

194 Principal professional engineer and resident engineer for cofferdam contract, MWH Global, Inc.700 West Wescor Road, Hawsville, Kentucky, 42348, [email protected].

139 NOTES

140 TEMPORARY AND PERMANENT DEWATERING OF EARTH EMBANKMENT DAMS TO FACILITATE REHABILITATION

Greg M. Landry, P.E.195 Cari R. Beenenga, P.E.196

ABSTRACT

Earth embankment dam stability is greatly affected by pore water pressures within the dam and related through- and under-seepage. Elevated pore pressures, with or without a high water table in the dam, increases the likelihood of failure by slope instability. Uncontrolled movement of water, through- or under-seepage, increases the likelihood of soil erosion, piping and loss of foundation or embankment mass. Additionally, excavations into an earth embankment dam for rehabilitation purposes must first consider the insitu conditions in the dam. Many situations occur during a rehabilitation effort that require lowering the phreatic surface within an earth embankment dam to provide safe, continued operation of the dam during rehabilitation.

Permanently lowering the water table in a dam through either actively or passively pumped wells and collection trenches can improve the factor of safety against slope failure and also prevent soil migration by collecting and discharging water through properly graded trench and well filters. Unfortunately, installation of a permanent dewatering system or groundwater collection system often requires excavating into the dam itself. This can be problematic, particularly for dams already in need of rehabilitation, since removing mass from the dam during excavation can change the dam’s global stability.

This paper will explore issues relating to designing and constructing permanent and temporary dewatering systems for earth embankment dams to mitigate these effects.The first half of the paper will discuss design of permanent dewatering systems, including subsurface investigation, groundwater and failure mode analysis, system design, maintenance, contractual language, and regulatory oversight and requirements. The second half of the paper will discuss issues related to design and implementation of temporary dewatering systems on dams, including flow rate estimation, the need for redundant designs, and opportunities for value engineering.

195Moretrench American Corporation, 100 Stickle Avenue, Rockaway, New Jersey 07866. [email protected] 196Gannett Fleming Inc., PO Box 67100, Harrisburg, PA [email protected]

141 NOTES

142 EFFECTIVE MODELING OF DAM-RESERVOIR INTERACTION EFFECTS USING ACOUSTIC FINITE ELEMENTS

Matthew Muto, Ph.D.197 Nicolas von Gersdorff, P.E.198 Zee Duron, Ph.D.199 Mike Knarr, P.E., S.E.200

ABSTRACT

Southern California Edison (SCE) is currently evaluating the seismic stability of two large concrete dams. Extensive finite-element analyses of these two dams are being performed to evaluate their response to large earthquakes. The earthquake analysis of these dams requires an accurate representation of dam-reservoir interactions to capture appropriate hydrodynamic loading and radiation damping effects.

Traditional modeling considerations for the reservoir include the use of lumped added masses or the use of finite fluid elements to represent a portion of the reservoir domain that attaches directly to the dam model. However, in a seismic analysis the elements can become excessively distorted, increasing the computational cost and potentially affecting the accuracy of the results. SCE has recently completed a series of evaluations that suggest modeling the reservoir domain as acoustic medium using finite elements that track only pressure, not deformation, can provide reliable representations of dam- reservoir interactions. These evaluations included comparisons between computed hydrodynamic pressure responses from numerical models with acoustic reservoir elements and measured hydrodynamic pressures acquired during forced vibration tests on a large concrete dam. Additional and enhanced confidence in the use of acoustic elements to model dam-reservoir interactions is gained by demonstrating that these elements can be used to obtain satisfactory comparisons in problems with known closed- form solutions.

The results presented in this paper show that the use of acoustic finite elements avoids some of the potential problems with traditional reservoir modeling techniques while providing comparable accuracy.

197 Southern California Edison, 300 N. Lone Hill Ave., San Dimas, CA 91773. [email protected] 198 Southern California Edison, 300 N. Lone Hill Ave., San Dimas, CA 91773. [email protected] 199 Harvey Mudd College, 1200 Platt Blvd, Claremont, CA 91711, [email protected] 200 Southern California Edison, 300 N. Lone Hill Ave., San Dimas, CA 91773, [email protected]

143 NOTES

144 USACE EMSWORTH DAM SPILLWAY GATES REHABILITATION

Michael Hanley201

ABSTRACT

The U.S. Army Corps of Engineers (USACE) Pittsburgh District has been gradually replacing aging electro-mechanical drive systems for 13 spillway gates on the Emsworth Lock and Dam at the headwaters of the Ohio River. This work is being done in conjunction with other efforts on the spillway such as scour protection and abutment wall rehabilitation. Started in 2002, the project involved replacement of the 1937 vintage chain-drive machinery. These original mechanical systems were failing and getting increasingly difficult to maintain. The replacement systems are state of the art hydraulic drive systems with PLC electronic controls which allow the spillway gates to be operated either locally or from remote locations.

Emsworth spillway dam controls water pool levels for the downtown area of Pittsburgh, Pennsylvania. Most of the downtown area street level is at elevations less than two feet above the average water level. The city is strategically located at the confluence of the Monongahela and Alleghany rivers. These two rivers meet at the pinnacle of downtown Pittsburgh and form the beginning of the Ohio River. Emsworth Dam is the first lock and dam structure for the Ohio River located just Northwest of Pittsburgh.

Details of the electrical, hydraulic, and mechanical systems will be reviewed. Unique aspects of the design include lifting of 200,000 pound spillway gates a total of 40 feet using hydraulic cylinders that have only a 30 foot stroke. This challenge required automated cycling of the cylinder bodies to get the additional 10 feet of stroke. Each 105 foot wide spillway gate has two independently operated hydraulic cylinders electronically controlled to keep the gate level within one inch.

Other areas of interest with regards to electronic monitoring of gate positions, data collection, and data logging for maintenance/operation efficiencies are discussed. Long term service expectations of the hydraulic cylinders and their unique floating cardanic ring (like a universal joint) design are also be reviewed in detail.

201 Vice President, Electro Hydraulic Machinery, 2501 John P Lyons Lane, Pembroke Park, FL 33009, [email protected]

145 NOTES

146 LEVEE CONSTRUCTION AND REMEDIATION USING ROLLER COMPACTED CONCRETE AND SOIL CEMENT

Carl M. Rizzo, CCM202 Charles W. Weatherford, P.E.203 Dr. Paul C. Rizzo, P.E.204 Contributor – John Bowen, ASI Constructors205

ABSTRACT

Roller Compacted Concrete (RCC) was pioneered in the 1970s as a low cost, rapid construction substitute for mass concrete placement primarily for large concrete dams. RCC is placed with earthmoving equipment, and the long-term strength of RCC is similar to concrete.

RCC consists of a zero slump mix of sand, gravel, cement, and water. Fly ash is sometimes used along with cement to reduce material costs and to reduce the heat of hydration. Soil Cement (SC) is similar to RCC but is typically produced with naturally occurring sands and silty sands instead of sand and gravel. While RCC is primarily used for large mass concrete dam construction, SC is typically used for slope and erosion protection for earthen dams and levees.

This paper will address advantages of RCC/SC construction over earthfill, placement methods and techniques, quality management, and contracting issues associated with the use of RCC or SC for levee remediation and construction.

202 Vice President Construction Management, Paul C. Rizzo Associates, Inc. – 500 Penn Center Boulevard, Suite 100, Pittsburgh, PA 15235 [email protected] 203 Resident Engineer, Paul C. Rizzo Associates, Inc. – 500 Penn Center Boulevard, Suite 100, Pittsburgh, PA 15235 [email protected] 204 President, Paul C. Rizzo Associates, Inc. – 500 Penn Center Boulevard, Suite 100, Pittsburgh, PA 15235 [email protected] 205 President, ASI Constructors – 1850 E. Platteville Boulevard, Pueblo West, CO 81007 [email protected]

147 NOTES

148 MANGLA DAM RAISING — PAKISTAN

J Dominic Molyneux, BEng, CEng, MICE206 Michael Hieatt, MA, CEng, C Env, FICE, FCIWEM, FGS207

ABSTRACT

The Mangla Dam project in Pakistan was the largest embankment dam project in the world when it was completed in 1967. The 260 square km reservoir is formed by four major dams, each with a different cross-section and each a significant structure. The original designs included provision for raising the dams by up to 12 m to offset the effects of future sedimentation. In 2000, capacity lost due to sedimentation became a significant issue and the Government of Pakistan decided to exploit the raising provisions of the original design, and store flood water which was routinely being released.

Following studies to confirm the most economic extent of raising, the original designs were reviewed and modified. Since the 1960’s there have been advances in geotechnical and seismic engineering, changes in design parameters and information from 40 years performance of the dams, all of which had to be taken into account in revisiting the original designs for the raising. As a result the dam cross-sections for the raised embankments have been adjusted using updated parameters and the opportunity taken to address some areas of seepage which have been under observation since the original construction.

Construction for a 9 m raise began in 2004 and was completed in December 2009. The total length of dam embankment after raising is 14 km with a maximum height of 148 m. The work required 31 million m3 of fill materials and is one of the largest dam raising projects ever undertaken.

206 Project Manager, Black & Veatch, 69 London Road, Redhill, RH1 1LQ, United Kingdom - [email protected] 207 Technical Director, Black & Veatch, Director MJV BOM, 69 London Road, Redhill, RH1 1LQ, United Kingdom - [email protected]

149 NOTES

150 LARGE-SCALE CONCRETE TESTING

Stephen B. Tatro, PE208 James K. Hinds, PE209

ABSTRACT

Large-scale laboratory testing using large specimens is not commonly done. The equipment and manpower required to produce the required concrete volume and the apparatus required to restrain and apply loads can be quite substantial. All are beyond the market capability of most testing organizations. However, large projects may realize significant benefits if properties of concrete from testing of large specimens can be determined.

This paper will provide guidelines for when large specimen testing may be advantageous. It will also provide recommendations on practical measures to implement when organizing such testing. The presentation is illustrated with an example of a project where production and testing of large specimens has been done. The example is from an RCC project where biaxial shear and direct tensile testing has been done. This is not intended to be a case study but a guidance document that may be applied to future projects.

208 Civil Engineer and Concrete Materials Specialist, Tatro Hinds Advanced Concrete Engineering, 148 Country Way, Walla Walla, WA 99362 (509) 240-6422, fax (509) 525-8671, [email protected] 209 Civil Engineer and Concrete Materials Specialist, Tatro Hinds Advanced Concrete Engineering, 40975 SE Latigo Lane, Sandy, OR 97055 (503) 505-1102, [email protected]

151 NOTES

152 INSPECTION OF TRUNNION RODS AT GREENUP DAM

Mark A Cesare210 J. Darrin Holt, P. E.211

ABSTRACT

Post-tensioned trunnion anchor rods are widely used as the structural support of Tainter gates at many dams throughout the United States. There may be hundreds of these rods that are used for transferring the Tainter gate forces to the monolithic structure of the dam. Previous failures have occurred in some rods whereby their post-tensioned stress levels have unknowingly released. When this occurs a rod may no longer function as originally intended. Identifying rods that have experienced such failure is a major problem for dam operators, a safety issue, and the subject of current research.

The Greenup Lock and Dam is located north of the town of Greenup, KY. Since its original construction, about 950 trunnion rod lift-off tests have been preformed to manually determine their in-situ states of tension. In 2010, a newly developed nondestructive test (NDT) utilizing Dispersive Wave Propagation was applied to 104 of Greenup’s trunnion rods to collect data used for making preliminary computation of their in-situ loads.

This paper describes the three-fold approach to nondestructively estimating tension in trunnion rods. These approaches are based upon historical data, Dispersive Wave Propagation and vibration studies, and the use of a limited number of lift-off tests for calibration and validation. Discussions will include a derivation of the mathematical model, a description of the statistical approaches applied, and a discussion of how computational estimates are made for a rod’s tension along with the statistical uncertainties.

210 FDH Engineering, Inc., 2730 Rowland Road, Raleigh NC 27616, [email protected]. 211 FDH Engineering, Inc., 2730 Rowland Road, Raleigh NC 27616, [email protected].

153 NOTES

154 IMPROVING DEBRIS MANAGEMENT AT LAKE LYNN DAM

Stefan Schadinger 212 Bryce Mochrie 213 Andrew Datsko214 Jacob Vozel 215

ABSTRACT

Lake Lynn Dam is a 125 foot high, 1,000 foot long hydropower project, located on the Cheat River in West Virginia, which consists of an integral intake/powerhouse, a gated spillway, and two concrete bulkheads. The dam is owned and operated by Allegheny Energy Supply, LLC and has been generating hydroelectric power with a rated capacity of 51.2 MW of power generation since construction was completed in 1926.

There is a history of debris buildup at Lake Lynn Dam, particularly during a 1985 flood, where almost all of the twenty six spillway gates were partially blocked. The significant amount of large debris reduced the spillway capacity, raised the reservoir level, and flooded the powerhouse. The accumulation of debris during high flows is a potential failure mode for the project, reducing spillway capacity, leading to higher flood elevations potentially causing stability problems.

Following the 1985 flood, it was determined that improved debris management was required. Several potential debris management options were then studied, including the installation of debris control measures upstream of the project and revising gate operation procedures to redirect debris. The results of these studies will be discussed in the paper.

The two existing trash gates are currently being replaced by a single larger hydraulically operated hinged crest gate, with an increased ability to flush trash and increased spillway capacity. The actual fabrication and installation will be discussed in the paper and included in the presentation. A 1,000 foot long log boom will also be installed to direct debris to the new trash gate. It is believed that the improved trash gate and the installation of the log boom will mitigate the potential for upstream flooding due to the accumulation of debris at the spillway.

212 Stefan Schadinger, Lead Engineer, PB Power, 75 Arlington St. Boston, MA 02116, (617) 960-4976, [email protected] 213 Bryce Mochrie, Senior Project Engineer, PB Power, 75 Arlington St. Boston, MA 02116, (617) 960- 4971, [email protected] 214 Andrew Datsko, Manager, FirstEnergy, PO Box 97, Lake Lynn Rd. Lake Lynn, PA 15451, [email protected] 215 Jacob Vozel, Engineer, FirstEnergy, 800 Cabin Hill Dr. Greensburg, PA 15601, (724) 830-5912, [email protected]

155 NOTES

156 COMPREHENSIVE SPILLWAY TAINTER GATE ASSESSMENT AND IDENTIFICATION OF INTERIM RISK REDUCTION MEASURES

Laurie Ebner216 Matt Craig217

ABSTRACT

The US Army Corps of Engineers (USACE) Portland District, CENWP, has 90 spillway Tainter gates. There are 42 gates at Projects in the Willamette Valley, 5 at Projects in the Rogue Basin, and 43 at Projects on the Columbia River. Since 2001 there have been various studies, inspections, and incidents that have prompted the Portland District to become concerned about the structural integrity and mechanical and electrical reliability of these gates. Buckling of tainter gate strut arms at three of the four tainter gates at Foster Dam in 2008 led to emergency tainter gate repairs. Observations of buckled tainter gate strut arms at Dexter Dam in December 2009 created urgency with respect to documenting the risk to the downstream population. In 2010, the district performed a comprehensive assessment of the tainter gates in the Willamette Valley and Rogue Basin projects. The comprehensive assessment included a gates specific potential failure modes analysis (PFMA), structural, mechanical and electrical assessments, identification of interim reduction measures and analysis of impacts of the interim reduction measures. As part of this assessment, the District developed a tool for prioritizing projects for gate repair based on the results of the assessment.

216 Hydraulic Engineer, US Army Corps of Engineers, Portland District, Portland, OR, [email protected]. 217 Civil Engineer, US Army Corps of Engineers, Portland District, Portland, OR, [email protected].

157 NOTES

158 MAINTENANCE AND REPAIR OF SPILLWAY GATES

Todd Schellhase, P.E., S.E.218

ABSTRACT

Significant attention is placed by owners and regulatory agencies, FERC being the lead, on assessing the condition of and maintaining spillway gates. Aging and other mechanical stresses can hamper the ability of these structures to operate especially under challenging conditions such as flooding or seismic events. This presentation details the process followed by one Texas utility for the rehabilitation of their spillway gates. The process to be explained begins with regulatory agency inspection and culminates with construction of modernization upgrades. Along the way numerous inspections, investigations, studies and reviews were undertaken to identify modernization alternatives.

This presentation focuses on the upgrades of spillway gates at two of the owner’s dams. Flow through one of the spillways is controlled by radial gates while the other spillway is controlled by both radial and roller gates. Problems common to the radial gates at both locations included corrosion of the skin plates and framing members, coating failure, seal aging and corrosion protection system deficiencies. Problems unique to the radial gates at the larger of the two spillways included an excessive amount of time required to open the gates, some gates which failed to fully open and corrosion of the hoisting equipment. Investigations also identified structural and mechanical deficiencies in the roller gates. The conscientious implementation of the spillway gate modernization plans will allow these valuable assets to continue to safely and reliably control flow through the spillways for years to come.

218 Todd Schellhase P.E., S.E., Engineering Manager, Hydropower and Hydraulic Structures, Black & Veatch, 8400 Ward Parkway, Kansas City, MO 64114, [email protected]

159 NOTES

160 COMPUTATIONAL MODELLING OF ADVANCED FLOW CHARACTERISTICS IN AERATED HIGH ENERGY SPILLWAYS

Kevin Franke219 Piroz Zamankhan220

ABSTRACT

The hydrodynamics in open channel flows are most challenging and obey complex physical laws. To choose the distance from the inlet of a spillway for an aeration device located on the spillway bottom to prevent the occurrence of cavitation is mostly a function of the channel slope, friction factor and water discharge. Nevertheless, for an accurate determination the evolvement of an aerated flow depending on bubble size and its distribution, suspended particles and the geometry of the aerator have to be taken into account. In this work, the analogy between a bubbly water flow in a tube and that of in a mixing tank compared to the flow behavior of an aerated spillway is used to distinguish the physical complexity. The analysis is mainly based on numerical modelling which is a combined large-eddy simulation technique (LES) and disceret element method. Three- dimensional simulations of an aerator are performed on a graphics processing unit (GPU). The simulation results are in agreement with the aforementioned experiments and confirm prior findings from physical models such as formation of bubble size, bubble coherence and separation and air concentration profiles. This promising effort in GPU computing could pave the way for developing advanced simulation techniques for the study of waterways and ports, as well as coastal and ocean engineering in the future.

219 Faculty of Civil and Environmental Engineering, University of Iceland, Hjarðarhagi 2-6, 107 Reykjavík, [email protected] 220 Faculty of Industrial-, Mechanical Engineering and Computer Sciences, University of Iceland, Hjarðarhagi 2-6, 107 Reykjavík, [email protected]

161 NOTES

162 POTENTIAL APPLICATIONS FOR PIANO KEY WEIRS AT DAMS IN THE UNITED STATES

Greg Paxson, PE221 Blake P. Tullis, PhD222 Dave Campbell, PE223

ABSTRACT

Similar to labyrinth weirs, piano key (PK) weirs are folded in plan to increase discharge capacity for a given spillway channel width. Because of their configuration, PK weirs may be better suited than labyrinth weirs for applications where the weir footprint (length and/or width) dimensions are restricted (e.g., crest of gravity dams) as PK weirs can facilitate a significant amount of weir length relative to their footprint size. For channel applications without significant footprint restrictions, labyrinth and PK weirs may both represent viable spillway options.

This paper provides an overview of some of the advantages and disadvantages of PK weirs, labyrinth weirs, and gated structures in channel applications and/or dam rehabilitation, including economic, structural, and hydraulic considerations. Two case studies are reviewed where a labyrinth weir or other type of control structure were constructed. The potential application of a PK weir was comparatively assessed for the same projects, had the option been available at the time of design.

221 Principal, Schnabel Engineering, 1380 Wilmington Pike, Suite 100, West Chester, PA 19382, 610-696- 6066, [email protected] 222 Associate Professor, Utah Water Research Laboratory, Utah State University, 8200 Old Main Hill, Logan, UT 84322, [email protected] 223 Director of Dam Engineering, Schnabel Engineering, 1380 Wilimington Pike, Suite 100, West Chester, PA 19382, 610-696-6066, [email protected]

163 NOTES

164 REVISITING SPILLWAY DISCHARGE COEFFICIENTS FOR SEVERAL WEIR SHAPES

William Kortney Brown, E.I.T.224 Gregory S. Paxson, P.E.225 Bruce Savage, PH.D., P.E.226

ABSTRACT

For practicing engineers, spillway discharge is often estimated with the weir equation, using discharge coefficients obtained from hydraulics textbooks or other publications. These discharge coefficients are typically considered to be accurate and appropriate since they have been widely published and used for many years. However, in some cases, the sources for these values are more than 100 years old and there is little documentation of the experiments that were used to develop the discharge coefficients.

Discharge coefficients for five weir shapes presented in “Handbook of Hydraulics” (Brater et al., 1996) are reevaluated through physical (flume) and Computational Fluid Dynamics (CFD) modeling and compared with the results published data. The results of the physical and CFD modeling are presented and compared with the historical data. This research suggests that applying the discharge coefficients published in Brater et al. may underestimate discharge for some of the weir shapes studied. The authors recommend further studies of these and other weir shapes.

This study also demonstrates the value of practicing engineers collaborating with local Universities. The relatively inexpensive study allowed the consultant to obtain specific, valuable data while providing research credentials to the University and providing degree credits to the author.

224 Senior Staff Professional, Schnabel Engineering, West Chester PA 19382, [email protected] 225 Principal, Schnabel Engineering, West Chester PA 19382, [email protected] 226 Assistant Professor, Department of Civil and Environmental Engineering, Idaho State University, Pocatello ID 83209, [email protected]

165 NOTES

166 USING THE SACRAMENTO SOIL MOISTURE ACCOUNTING MODEL TO IMPROVE FLOOD FREQUENCY ESTIMATES FOR DAM SAFETY

Frank Dworak227

ABSTRACT

The Bureau of Reclamation uses multiple methods to develop hydrologic loadings for dam safety risk analysis. Hydrologic hazard estimates typically consist of peak flow frequency, volume frequency, and flood hydrographs for a full range of Annual Exceedance Probabilities (AEPs). The methods used to estimate hydrologic hazard include deterministic and stochastic modeling approaches often requiring rainfall-runoff models. The use of rainfall-runoff modeling introduces potential for error and increased project cost in model development and calibration. Reclamation has begun to use the Sacramento Soil Moisture Accounting (SAC-SMA) model in drainage basins already being modeled by the National Weather Service (NWS) to improve hydrologic hazard estimates while reducing model calibration, setup, and project cost.

SAC-SMA is a continuous soil moisture accounting model with spatially lumped parameters. The model is ideal for large drainage basins and uses multiple years of records for calibration. There are many advantages in using the SAC-SMA model for hydrologic hazard estimates, including: the model is calibrated to actual basin parameters, snowmelt is also modeled, precipitation is a unique input and can be easily manipulated, and the model can be automated to run multiple iterations.

A case study of East Park Dam, California is presented to demonstrate how the SAC- SMA model was used to make hydrologic hazard estimates for dam safety. A detailed hydrologic hazard study was conducted for East Park Dam, California using multiple methods. One of the methods used was a custom rainfall-runoff modeling method with L-moments precipitation and the SAC-SMA model; the second method was peak-flow frequency with site-specific paleoflood data collection. The study used the SAC-SMA model in a quasi Monte Carlo type approach to calculate runoff for a large range of hydrologic conditions and frequency rainfall. Code written in the Python programming language was used to automate the model runs allowing several thousand iterations of the model. This approach resulted in improved estimates for the hydrologic hazard at East Park Dam from preliminary studies, and increased potential for use of the SAC-SMA model in future studies.

227 Hydraulic Engineer, Flood Hydrology and Emergency Management Group, 86-68250, Bureau of Reclamation, Denver, CO 80225, [email protected]

167 NOTES

168 SITE-SPECIFIC PMP FOR NORTH TEXAS: BRINGING HMR 51 INTO THE 21ST CENTURY

Bill Kappel228 Ed Tomlinson, Ph.D.229 Courtney Jalbert230 Louie Verreault231

ABSTRACT

As part of an ongoing effort to evaluate continued performance of Tarrant Regional Water District (TRWD) dams, the TRWD Dam Safety Program is actively re-evaluating some of its aging infrastructure. Since design of some structures was completed in the 1920s, TRWD is comparing performance to modern standards and, if indicated, designing remedial measures. A geotechnical stability review and analysis is currently underway, and in 2009 an updated probable maximum flood (PMF) study was completed for one of the four reservoirs. The final component evaluated was the probable maximum precipitation (PMP) values. The PMP directly affects the resulting PMF and updated PMP values allow for PMF updates for all four TRWD basins.

In 1978 the National Weather Service (NWS) published Hydrometeorological Report No. 51 (HMR 51). The most recent storm used in HMR 51 to derive PMP values for the TRWD region occurred in 1954, so TRWD recognized the need for an updated PMP analysis. Due to limited funding and staffing, the NWS no longer produces PMP estimates. TRWD turned to Applied Weather Associates (AWA), a company with 17 years of experience producing site-specific, statewide, and regional PMP studies. For this study, AWA identified the most significant recent storms that have occurred over geographic regions that are topographically and climatologically similar to the TRWD basins. Several new extreme rainfall storms were identified, analyzed, and used along with storms in HMR 51 to determine PMP values for the TRWD basins. The study results reduced PMP compared to HMR 51 by as much as 21% for the TRWD basins. Study methods, process, data, and results are presented and discussed.

228 Vice President and Senior Meteorologist, Applied Weather Associates, PO Box 860, Monument, CO 80132, [email protected] 229 President and Chief Meteorologist, Applied Weather Associates, PO Box 860, Monument, CO 80132, [email protected] 230 Meteorologist, Tarrant Regional Water District, 808 E. Northside Dr, Ft Worth, TX 76102, [email protected] 231 Professional Engineer, Tarrant Regional Water District, 808 E. Northside Dr, Ft Worth, TX 76102, [email protected]

169 NOTES

170 IMPROVING HYDROLOGIC ANALYSIS AND APPLICATIONS USING QUALITY WEATHER RADAR DATA AND THE STORM PRECIPITATION ANALYSIS SYSTEM

Ed M. Tomlinson, PhD232 Tye W. Parzybok233 Bill D. Kappel234 Doug M. Hultstrand235 Beth Clarke236

ABSTRACT

The use of radar estimated precipitation is among the most important technological advancements improving the accuracy and reliability of hydrologic models in recent years. Not surprisingly, the use of radar estimated precipitation is a significant area of research and is applied operationally in a number of practical applications, such as reservoir inflow monitoring, water resources management, stormwater management, and flood warning systems.

Radar data far exceeds the spatial densities of rain gauge networks and has a finer temporal scale (as frequent as 5-minutes) than traditional rain gauges, therefore allowing precipitation estimates to be made at all ungauged locations. While radar estimated precipitation provides a great improvement in temporal and spatial scales for hydrologic modelling, the radar precipitation estimates require correction adjustments to account for under/over estimations, radar beam blockage, hail contamination and radar-precipitation relationships.

The Storm Precipitation Analysis System (SPAS) includes state-of-the-science advances in spatial and temporal radar-aided precipitation analysis. Utilizing Weather Decision Technology’s (WDT) quality controlled Level-II radar data, SPAS utilizes hourly algorithms and correction adjustments to improve the accuracy and reliability of radar- estimated precipitation for use in many applications, including civil infrastructure design and operational hydrology. For many years, SPAS operated as a post-storm analysis tool, providing hydrologic models the necessary high-resolution precipitation data for calibration and validation. However, SPAS has evolved to have near real-time capabilities using innovative, state-of-the-science techniques. An overview of SPAS real-time (SPASRT), WDT’s radar processing, and a comparison of precipitation using different radar inputs and Z-R algorithms are provided.

232 President and Chief Meteorologist, Applied Weather Associates, PO Box 860, Monument, CO 80132, [email protected] 233 President, Metstat, Inc, Windsor, CO, [email protected] 234 Vice President and Senior Meteorologist, Applied Weather Associates, PO Box 860, Monument, CO 80132, [email protected] 235 Hydrometeorologist, Applied Weather Associates, PO Box 860, Monument, CO 80132, [email protected] 236 Meteorologist, Weather Decision Technologies, Norman, OK, [email protected]

171 NOTES

172 DAM BREACH MODELING WITH UNSTEADY HEC-RAS: COMMON TECHNIQUES AND ASSUMPTIONS COMPARED

Sunit Deo, P.E.237 Scott M. Muchard, P.E.238

ABSTRACT

Unsteady flow modeling is often used in dam breach analysis due to regulatory requirements or the need to obtain more detailed or accurate results for inundation mapping than a simplified steady-state model can provide. However, use of unsteady models, such as the unsteady flow dam breach component within The U.S. Army Corps of Engineers Hydrologic Engineering Center - River Analysis System (HEC-RAS), can be time consuming and have extensive data requirements. Unsteady modeling of various aspects of the dam failure and downstream flood wave propagation with HEC-RAS can be performed using differing techniques and assumptions. This paper discusses some of the commonly used techniques and assumptions and, through case studies on several dams in Texas and Kentucky, compares the results obtained with each technique or assumption.

237 HDR Engineering, Inc., 4401 West Gate Blvd., Suite 400, Austin, TX, 78745, [email protected]. 238 HDR Engineering, Inc., 4401 West Gate Blvd., Suite 400, Austin, TX, 78745, [email protected].

173 NOTES

174 DEVELOPMENT AND IMPLEMENTATION OF WEB-BASED DAM-BREAK FLOOD INUNDATION ANALYSIS CAPABILITIES

Mustafa S. Altinakar, PhD 239 Enrique E. Matheu, PhD 240 Marcus Z. McGrath 241 Vijay P. Ramalingam 242 Jun Z. Zou, PE 243

ABSTRACT

The Dams Sector Analysis Tool (DSAT) is a Web-based tool that provides users with secure access to a wide range of analytical capabilities. In particular, DSAT provides users with access to the advanced flood modeling capabilities developed by the National Center for Computational Hydroscience and Engineering of the University of Mississippi (UM-NCCHE). Implementation of this capability is the result of a joint effort between UM-NCCHE and the U.S. Department of Homeland Security (DHS), Office of Infrastructure Protection. The flood modeling computational tools were developed at UM-NCCHE with support provided by the DHS-sponsored Southeast Region Research Initiative (SERRI) Program at the Oak Ridge National Laboratory.

To run an automated dam-break flood simulation, the user provides the basic input data using the DSAT Viewer. The data defining the scenario to be simulated is transmitted to a dedicated NCCHE server, which hosts the Decision Support System for Water Infrastructural Security (DSS-WISE). Special procedures allow the preparation of the computational domain and the input data fully automatically without user intervention. The simulations are carried out using the DSS-WISE, which employs a multi-core, multi- threaded implementation of a first-order, shock-capturing finite volume scheme that solves the full dynamic shallow water equations governing the flow of flood waters over complex topography. The solver can handle mixed flow regimes (subcritical, transcritical, supercritical). Once the simulation is completed, the output files, representing the flood depth and flood arrival-time grids, can be uploaded on the DSAT viewer for further analysis.

239 Director and Research Professor, National Center for Computational Hydroscience and Engineering, The University of Mississippi, Oxford, MS 38677. 240 Chief, Dams Sector Branch, Sector-Specific Agency Executive Management Office, Office of Infrastructure Protection, U.S. Department of Homeland Security, Washington, DC 20598. 241 Graduate Student, National Center for Computational Hydroscience and Engineering, The University of Mississippi, Oxford, MS 38677. 242 Scientific Software Developer, National Center for Computational Hydroscience and Engineering, The University of Mississippi, Oxford, MS 38677. 243 Civil Engineer, Dams Sector Branch, Sector-Specific Agency Executive Management Office, Office of Infrastructure Protection, U.S. Department of Homeland Security, Washington, DC 20598.

175 NOTES

176 DAM-BREAK FLOOD INUNDATION ANALYSIS FOR LAKE YOUNGS RESERVOIR

Henry Hu244 John Howard245 Daniel Huang246

ABSTRACT

A dam failure analysis was conducted for the Seattle Public Utilities to determine the flood inundation extents of a hypothetical failure of the Lake Youngs Reservoir Outlet Dam in King County, Washington. The 690-acre reservoir is unique as it is completely impounded by embankments and perimeter dikes without receiving natural inflows. The lake is filled with water piped from the Cedar River and serves as an intake regulation reservoir for the Metropolitan Seattle Area drinking water supply system. The Outlet Dam is classified as High, Hazard Class 1A and failure could potentially place a large number of people and property along the Soos Creek and Green River valley in danger. An unsteady flow HEC-RAS model was developed for a sunny day failure, a winter failure, and a probable maximum flood failure. This paper discusses the methods and assumptions used to build the HEC-RAS model. The paper presents dam break flood routing results, including the travel time (warning time) of the flood wave to various key locations in the downstream valley and the representative channel/valley cross-sections depicting flow depth and typical flow velocities. It finally presents the elements and information depicted on an inundation map, which is used by stakeholders and public agencies for the purpose of emergency alert and management.

244 Senior Project Manager, WEST Consultants, Inc., 12509 Bel-Red Road, Suite 100, Bellevue, WA 98005, [email protected]. 245 Project Engineer, WEST Consultants, Inc., 12509 Bel-Red Road, Suite 100, Bellevue, WA 98005, [email protected]. 246 Supervising Senior Engineer, Seattle Public Utilities, 700 Fifth Avenue, Suite 4900, Seattle, WA 98124, [email protected].

177 NOTES

178 DAM BREACH ANALYSIS SIMULATION ON THE LOWER SUSQUEHANNA RIVER

Jay Greska247 Bryce Mochrie 248 Chii-Ell Tsai 249 Christopher Godwin 250

ABSTRACT

Recent advances in unsteady flow modeling enhance the ability of engineers to predict the effects of dam failures and other unanticipated releases on low-lying areas, thereby reducing the risk to lives and property. Using a HEC-RAS one-dimensional hydrodynamic model of the lower Susquehanna River, the authors re-created the flood of record (Hurricane Agnes in June 1972), simulated the Probable Maximum Flood (PMF), and estimated downstream impacts associated with the failure of Safe Harbor Dam in southern Pennsylvania under both sunny day and PMF conditions.

Using cross section data obtained from FEMA, the authors created a HEC-RAS model of the river, beginning 7.6 miles below Safe Harbor at Holtwood Dam, and extending 10.7 miles above Safe Harbor to Wrightsville. Using as-built drawings, the model was revised to include Safe Harbor Dam and its 31 spillway gates. A rating curve for the concrete spillway, flashboards and rubber dams originally in use at Holtwood Dam was used to establish downstream boundary conditions. The model was then calibrated based on water surface elevations observed during Hurricane Agnes, and at lesser discharges.

Using a revised rating curve based on current conditions at the downstream facility (flashboards in place on entire spillway), this calibrated model was then used to estimate downstream stages and discharges associated with various failure scenarios at Safe Harbor Dam. For the sunny day breach, a 0.20 hour time to failure was assumed and the dam’s spillway gates are closed, with all flow directed through the Safe Harbor powerhouse prior to the breach. The PMF breach, like the sunny day, is also based on a 0.20 hour time to failure. The results of the analysis were used to update the Emergency Action Plan, including the downstream inundation maps.

247 Jay Greska, Lead Engineer, PB Power, Boston, MA 02116, (617) 960-5021, [email protected] 248 Bryce Mochrie, Senior Project Engineer, PB Power, Boston, MA 02116, (617) 960-4971, [email protected] 249 Chii-Ell Tsai, Supervising Engineer, PB Power, Boston, MA 02116, (617) 960-4974, [email protected] 250 Christopher Godwin, Civil Engineer, PB Power, Boston, MA 02116, (617) 960-5025, [email protected]

179 NOTES

180 WAVE OVERTOPPING HYDRAULIC PARAMETERS ON PROTECTED-SIDE SLOPES

Steven Hughes251 Bryan Scholl252 Christopher Thornton253

ABSTRACT

During irregular wave overtopping, the protected (landward) side of an earthen levee is subjected to unsteady hydrodynamic loading characterized by short-duration peak loads that are many times greater than the average loading. Recent experiments at full scale and laboratory experiments at smaller scale have provided useful new measurements that help characterize wave overtopping in terms of engineering design parameters. This paper presents new results obtained from measurements made during full-scale wave overtopping simulations conducted in the new Wave Overtopping Test Facility at Colorado State University. The tested landward-side levee geometry consisted of a 28-ft- long 1-on-3 slope transitioning to a 12-ft-long berm with a 1-on-25 slope. Synoptic, measurements of instantaneous flow thickness were made using both bottom-mounted pressure gauges and “surfboards” that floated on the water surface. Instantaneous velocities near the water surface were measured using rotating “paddlewheels” housed in the surfboard. Measurements were acquired at numerous locations on the levee slope and berm. The amount of air entrained into the flow was quantified by using multiple instruments at the same location. The largest overtopping hydraulic loading occurred at the transition between the 1-on-3 slope and the mild sloping berm, a known location for problematic erosion. Localized centrifugal forces acting near the transition during the unsteady wave overtopping can be quantified and represented as a localized “effective discharge.”

251 Senior Research Scientist, Colorado State University, USA. [email protected] 252 PhD Candidate, Colorado State University, USA. [email protected]. 253 Director, Engineering Research Center, Colorado State University, USA. [email protected].

181 NOTES

182 NEW RESERVOIR MODELS FOR OKLAHOMA

John Ruhl254 Dr. B. Dan Hernandez255

ABSTRACT

The USACE Tulsa District asked Black & Veatch to develop unsteady- and steady-state HEC-RAS models for over 2000 miles of river reaches downstream of 17 reservoirs in the watersheds of the Arkansas River and Red River. Flood inundation maps for the 10- year, 50-year, 100-year, and 500-year flood events were prepared from the model results. HEC-FIA economic models were also developed. A web application will allow the Tulsa District to manage and update the information in future years.

Management of geospatial data on a very large geographic scale was required. The data included elevation data from the USGS National Elevation Dataset and raster images. The GIS activities have included development of stream centerlines and banklines, a stream burning process to establish a uniform slope and channel shape, and a script to automate the Manning's "n" value development.

Information from the Water Control Manuals was used to prepare the reservoir gate information used in the unsteady models of the spillway design floods. The economic analyses were prepared at a basic level of detail using the results of the steady-state models throughout most of the river reaches and at a greater level of detail for one reach using the unsteady-state model results. The unsteady-state models will be used by the Tulsa District Risk Management Center Cadre (RMC) to refine numerical methodologies to predict flood inundation due to events such as dam break, levee breach, and flash flood. Evacuation plans for affected communities will be able to be developed.

254 Black & Veatch, 6601 College Blvd., Overland Park, KS, [email protected] 255 Corps of Engineers, Tulsa District, 1645 S. 101 E. Ave, Tulsa, [email protected]

183 NOTES

184 ANALYSIS OF DAM RESPONSE UNDER FOUNDATION FAULTING

Lelio Mejia256 Ethan Dawson257

ABSTRACT

Considerable experience has been gained by the engineering profession over the past 40 years with the seismic performance of dams subjected to earthquake shaking. Significant progress has also been made in developing procedures to evaluate the effects of earthquake shaking on dams. On the other hand, modest experience is available regarding the evaluation of dams for the effects of foundation fault rupture. Although insightful research on the subject has been carried out in recent years, procedures for the analysis of foundation rupture effects on dams have not been well established.

This paper aims at contributing to the knowledge and experience on the subject by presenting an overview of factors to be considered in the analysis of embankment dams for foundation faulting, and by describing an approach to analyze the effects of foundation faulting on embankment dam stability. The approach is illustrated with the case history of Aviemore Dam.

256 Principal Engineer, URS Corporation, Oakland, California, USA 257 Senior Project Engineer, URS Corporation, Los Angeles, California, USA

185 NOTES

186 CONSIDERATIONS FOR DEFORMATION ANALYSES FOR SUBDUCTION ZONE EARTHQUAKE LOADINGS

Bryan M. Scott, Ph.D., P.E.258 Navead C. Jensen 259

ABSTRACT

Recent global seismic events and a better understanding of subduction zone behavior have placed an increased emphasis on analyzing the effects of long duration shaking on earth embankments. Analytical tools that have largely been developed with shorter events in mind may not accurately account for the effects of long duration shaking. When analyzing long duration shaking within the finite difference framework of FLAC, force imbalances due to large deformations are magnified by long duration loading records, leading to unrealistic deformations and misleading results.

With large deformations that can accompany long duration shaking, the mass within the model is redistributed such that initial static reaction forces may not reasonably balance the deformed mass. Additionally, reservoir pressures calculated for the undeformed embankment may not accurately represent the pressures that should be applied to the deformed embankment. These phenomena lead to force imbalances that can cause significant distortion of the model. This distortion is increased when the unbalanced forces act over the extended time associated with subduction zone loadings. Even when incorporating an increased bedrock thickness in the model, significant distortion may remain for long duration loadings.

Using FLAC’s internal programming language, an approach was developed to update reservoir pressures and reaction forces that significantly reduces the force imbalance and mitigates the effects of any remaining unbalanced forces. The force updating routines recalculate correct reservoir pressures and reaction forces associated with the constantly deforming model. After correctly accounting for these forces, the increased confidence in the results can lead to more economical designs.

258 United States Bureau of Reclamation, Denver Federal Center, Bldg. 67, 11th floor, PO Box 25007 (86- 68312), Denver, CO, 80225-0007, 303-445-2977, [email protected] 259 United States Bureau of Reclamation, Denver Federal Center, Bldg. 67, 11th floor, PO Box 25007 (86- 68311), Denver, CO, 80225-0007, 303-445-3142, [email protected]

187 NOTES

188 SHAKEN, BUT NOT STIRRED — EARTHQUAKE PERFORMANCE OF CONCRETE DAMS

Larry K. Nuss, P.E.260 Norihisa Matsumoto261 Kenneth D. Hansen, P.E.262

ABSTRACT

One real-life full-scale experience is worth a hundred opinions. Such is the experience gained from the performance of concrete dams that have been severely shaken by actual earthquakes. This paper presents data from 19 concrete dams that have been shaken by Peak Horizontal Ground Accelerations (PHGA) exceeding 0.3 g during earthquakes worldwide. This historical perspective goes back more than 100 years.

Case histories are presented for each type of concrete dam: gravity, arch, and buttress dams. Case histories were selected based on a number of factors including: 1) importance of the dam, 2) severity of the ground motion, 3) occurrence or lack of observed damage, and 4) availability of quality strong motion records at or near the dam.

The case histories include reports on 1) the first two roller-compacted concrete (RCC) dams subjected to high base accelerations, 2) the first reported “failure” of a concrete dam due to a rupture of a fault below the structure, 3) three dams experiencing more than 2.0 g acceleration at the crest, 4) two dams shaken by two significant earthquakes, and 5) the performance of concrete dams subjected to the 2011 Tohoku Earthquake off the coast of Japan. Of interest is that one concrete gravity dam had significant acceleration amplification from the base to the crest of the dam in the cross-canyon direction.

The performance of each type of concrete dam is summarized, including the lessons learned. The paper includes a table listing all the dams, the date of construction, the height and crest length, earthquake specifics, the PHGA at the dam, and the reported dam response. The reasons why concrete dams have outperformed their design criteria or analysis is discussed.

260 Larry K. Nuss, Structural Engineer, (Bureau of Reclamation - retired), 4502 South Hoyt Street, Littleton, Colorado, 80123, 303-517-8504, [email protected]. 261 Norihisa Matsumoto, Advisor, Japan Dam Engineering Center (JDEC) and Executive Director, Japan Commission on Large Dams (JCOLD), +81-3-5815-4161, [email protected]. 262 Kenneth D. Hansen, Consulting Engineer, 6050 Greenwood Plaza Blvd., Suite 100, Greenwood Village, Colorado, 80111, 303-695-6500, [email protected].

189 NOTES

190 HUME DAM — SEISMIC ANALYSIS OF SOIL/STRUCTURE INTERACTION

Guy Lund263 Brad Dawson264 Mark Foster265

ABSTRACT

Hume Dam is located near Albury/Wodonga, Australia and was constructed between 1919 and 1936. The reservoir was enlarged in the 1960s to its current capacity of 3,038,000 megaliters (2.5 × 106 acre-feet). It is the main regulating reservoir on the River Murray System and supplies irrigation water and hydro-electric power. State Water Corporation (State Water) on behalf of the Murray Darling Basin Authority (MDBA) currently manages the dam and reservoir.

The main dam consists of an embankment dam with a concrete core wall and a gated concrete gravity spillway. Spillway discharges flow through the gates, over the ogee gravity section, and into the river through a discharge channel. The flow is trained with large concrete training wall on both the right and left side of the discharge channel. The left, southern training wall (STW) is located between the spillway channel and the main embankment, and retains the embankment fill as well as containing the spillway discharges. The height of the STW varies from approximately 50 meters (165 feet) near the crest of the embankment dam to 18 meters (60 feet) at the downstream end, and is the subject of this paper.

Modifications have been performed on the STW over the last few decades to improve stability due to the increased loads caused by severe deformation of the embankment. The modifications have included installation of sub-vertical post-tensioned tendons and horizontal post-tensioned anchors. However, continued embankment deformation has resulted in the need for additional rehabilitation. In addition, it is understood that the critical loading condition is due to the safety evaluation earthquake (SEE), and a significant portion of the load is dependent on the combined behavior of the embankment fill and the mass concrete wall.

The finite element method of analysis was used to analyze the soil/structure interaction and the behavior of the STW for both static and dynamic loads. This paper summarizes the finite element model, parameter assumptions, and sensitivity studies used to verify the behavior of the model with the actual STW, and the results used to develop the design modification.

263 P.E., Principal Civil/Structural Engineer, URS Corporation, Denver 264 P.E., Civil/Mechanical Engineer, URS Corporation., Denver 265 CP Eng., Project Manager, URS Australia., Sydney, Australia

191 NOTES

192 GENERAL APPROACH USED FOR THE SEISMIC REMEDIATION OF PERRIS DAM

Steven Friesen, P.E.266 Ariya Balakrishnan, Ph.D., G.E.267

ABSTRACT

Remediation for Perris Dam has been proposed in response to deficiencies identified in a recent seismic stability study. Lenses of potentially liquefiable soil have been identified within the dam foundation which may lose strength during a seismic event leading to unacceptable deformation of the dam. The remediation will rely on cement deep soil mixing (CDSM) to strengthen the foundation and construction of a downstream berm to stabilize the dam. Since most of the liquefiable lenses will remain under the dam, residual strengths for these lenses were estimated by averaging values from two methods based on representative Standard Penetration Test (SPT) blowcounts. To manage analytical time and effort of performing multiple iterative analyses of many sections of the dam, the selection process of the remediation design parameters relied primarily on pseudostatic models using both limit equilibrium (SLOPE/W) and finite difference (FLAC) factor of safety analyses. The geometry of the berm and CDSM was determined based on a minimum factor of safety of 1.1 with a horizontal seismic load of 0.15g. This pseudostatic design criterion was selected based on preliminary Newmark deformation analyses that produced acceptable deformations for the design earthquake. Deformation of the remediated dam was then confirmed using both Newmark and nonlinear FLAC deformation analyses.

266 California Department of Water Resources, 1416 Ninth St #538 Sacramento CA 95814, (916) 657-4913, [email protected]. 267 California Department of Water Resources, 1416 Ninth St #510-6 Sacramento CA 95814, (916) 653- 8478, [email protected].

193 NOTES

194 EVALUATION FOR FUNDAMENTAL PERIODS OF KOREAN ROCKFILL DAMS WITH MICRO-EARTHQUAKE RECORDS

Ik-Soo, Ha268 Dong-Hoon, Shin269 Jeong-Yeul, Lim270

ABSTRACT

The purpose of this study was to identify a method that can reliably evaluate the fundamental period of a rockfill dam using the micro-earthquake records, which were obtained at Korean dam sites. For total 20 micro-earthquake records obtained at 7 Korean rockfill dam sites during 6 earthquake events which recently occurred, the fundamental periods of the dams were evaluated by two methods; one is a method using acceleration amplification ratio and the other is a method using acceleration response spectrum ratio. The applicability of each method to the evaluation of the fundamental periods of Korean rockfill dams was examined. In the moderate seismicity region like Korea, the method evaluating the fundamental period of the rockfill dam using acceleration response spectrum ratio, that is, the ratio between the response spectrum for acceleration observed at the dam crest and the response spectrum for acceleration observed at the dam base or abutment, proved to be reliable and was proposed in this study. From the examination results, it was found that the selected and proposed method could consistently evaluate the fundamental periods of rockfill dams and the results obtained by the proposed method were very similar to the results by the existing method which was proposed by Okamoto (1984) from the analysis for the earthquake records observed at Japanese dam sites.

268 Assistant Professor, Dep. of Civil Engineering, Kyungnam University, Changwon, Republic of Korea, [email protected] 269 Director, Infrastructure Technology Center, Korea Resources Corporation(K-water), Daejeon, Republic of Korea, [email protected] 270 Principal Researcher, Infrastructure Technology Center, K-water, Daejeon, Republic of Korea, [email protected]

195 NOTES

196 EFFECT OF EARTHQUAKE ON EMBANKMENT DAMS

Dr. Gopi Siddappa271

ABSTRACT

An earthquake is a vibration of the earth produced by a rapid release of energy. An earthquake only occurs for a few brief moments; the aftershocks can continue for weeks; the damage can continue for years. The present work deals with an important and complex issue in geotechnical and earthquake engineering, which concerns the influence of both elasticity and pore water pressure on the seismic response of earthen dams to artificial earthquake records using the finite element program GEOSTUDIO QUAKE/ W.

The study includes observation during earthquake loading, the different methods of seismic analysis of earth dams, such as the simplified methods, the empirical methods, the equivalent-linear analyses and the non linear methods. The study presents numerical analyses of the seismic behavior of homogeneous and cored earthen dams. The analysis is first conducted for a simple case which concerns the elastic response of the earthen dam. This analysis provides some indications about the response of the dam, mainly the dynamic amplification and pore water generation. For the elastic analyses, a parametric study is conducted for the investigation of the influence of major parameters such as the mechanical properties of the earth material density and soil stiffness. If the post- earthquake stability analyses indicate factors of safety against sliding above 1.0, the expected amount of deformation can be estimated using several methods. The most rigorous method is to use finite element or finite difference programs.

271 Professor, Department of Civil Engineering, P.E.S. College of Engineering, MANDYA– 5710401, Karnataka State, INDIA. Phone: 91-9448745759. e-mail: [email protected]

197 NOTES

198 QUALITY CONTROL AND QUALITY ASSURANCE IN CUT-OFF WALLS

Dr. D.A. Bruce272 Prof. G. Filz273

ABSTRACT

There is an unprecedented level of activity in the construction of cut-off walls for existing dams and levees. Such cut-off walls range in type from Category 1 walls (i.e., excavated soil and total replacement with an engineered “backfill”) to Category 2 walls (i.e., some form of Deep Mixing). This paper provides, for each wall type, a description of the various tests and assessments which are used to quantify the various parameters upon which acceptance is typically based. These are principally homogeneity, strength and permeability. It highlights how certain tests may not be wholly appropriate for different types of walls ─ an issue which is often at the source of contractual disputes.

272President, Geosystems, L.P., P.O. Box 237, Venetia, PA 15367, U.S.A., Phone: 724-942-0570, Fax: 724-942-1911, [email protected]. 273 Virginia Polytechnic Institute and State University, Department of Civil Engineering, Blacksburg, VA 24061, U.S.A., Phone: 540-231-7151, Fax: (540) 231-7532, [email protected].

199 NOTES

200 NEW DEVELOPMENTS AND IMPORTANT CONSIDERATIONS FOR STANDARD PENETRATION TESTING FOR LIQUEFACTION EVALUATIONS

Jeffrey A Farrar M.S., P E274

ABSTRACT

Standard Penetration Tests (SPT) are often used for evaluating earthquake induced ground liquefaction for dam safety evaluations. A procedure for SPT testing for liquefaction potential is specified in American Society for Testing and Materials (ASTM) standard D 6066. In gravelly soils it is recommended to perform SPT and record penetration per blow. A new laser distance finder has been developed to record penetration per blow data. Automatic hammer systems are preferred for testing and because they are rate dependent corrections for rate must be made. Other factors which affect the test such as long drill rods and other mechanical and operator variables are presented.

274 U S Bureau of Reclamation, Technical Service Center, Denver CO, 303-445-2333, [email protected]

201 NOTES

202 INSTALLATION OF CONCRETE CUT-OFF WALLS BY HYDROCUTTERS — A SAFE AND ECONOMICAL APPROACH FOR A DURABLE SOLUTION

Peter E. Banzhaf275 Martin Hoegg276 Philip J. Snyder277

ABSTRACT

The construction for a sustainable water management is directly related to the approach for a durable and economical foundation of hydro structures, whether it is for dams or levees. Design and planning of new dams and of dam rehabilitations/remediation lays the basis for durability of the structure and cost effectiveness of the construction works. The importance of the foundation in general is known and not the subject-matter of this paper. However, the effective and durable seepage control is a key-issue for a sustainable structure, hence a basis for sustainable water management.

The paper will discuss the advantages of concrete-barrier-walls installed by the latest hydrocutter technology; the requirements of pretreatments in different soil-rock conditions versus the general approach by a drilling and grouting campaign as a preliminary measure and the requirement of a containment wall for the installation of a concrete cut-off wall still considering dam safety as being the main focus.

To illustrate the topics, approach and lessons learned supported by evaluation, matrixes and tables form part of the paper. The effective pretreatment of alluvial and colluvial geology or of karst formations as well as the complete closure of gorges is a technique in state-of the art foundation technology.

The hydrocutter technology has proven itself both a successful and economical means to install concrete cut-off walls in very hard rock at great depths. This hydrocutter technique combined with the experience to design and install plastic concrete for durable barrier walls are available for the designers of sustainable seepage mitigation structures under new dams or in and below aging dams.

Project experiences and innovative approaches on selected construction sites involving plastic concrete cut-off walls installed by hydrocutters for effective seepage control will supplement the paper and the presentation.

275 Dipl.-Ing., BAUER Spezialtiefbau GmbH, BAUER-Str. 1, 86529 Schrobenhausen, Germany, Tel. +49 8252 97-0, [email protected] 276 Dipl.-Ing., BAUER Foundation Corp., 13203 Byrd Legg Drive, Odessa, FL 33556, Phone (727) 536- 4748, [email protected] 277 P.E., GEI Consultants, Inc., 400 Unicorn Park, Woburn, MA 01801, Phone (781) 721-4085, [email protected]

203 NOTES

204 A NEW ZONED EMBANKMENT DAM AND CUTOFF WALL IN PIEDMONT GEOLOGY

Dennis Hogan, P.E.278 Greg Zamensky, P.E.279

ABSTRACT

In response to the water scarcity issues that are evident throughout the Southeastern United States, a joint venture by Union County, NC and Lancaster County Water and Sewer District (LCWSD), SC undertook the design of a 100 foot high, 1,500 foot long zoned earth embankment dam to impound a new 100 million gallon pumped storage reservoir. The pumped storage scheme upgrades the existing pump station, piping, and smaller existing reservoir.

The project included an extensive geotechnical investigation in the challenging Piedmont Geology. The focus of the investigation was to maximize the use of on-site materials for the embankment construction and minimize external impacts. A cutoff wall will be installed from the existing valley surface, through saprolite, to the top of bedrock to provide for seepage protection in the foundation. The embankment core will be built onto the embedded cutoff wall. Elastic silts and clays from on site will be processed and utilized as the core of the earth embankment dam, and on-site alluvial deposits will be utilized as best possible for processing filter and shell materials.

A unique aspect is the fact that the embankment dam will not have a low-level outlet through the body of the dam. Drawdown of the reservoir will be achieved using a new pump station tower within the reservoir that will operate as the intake and outlet. The pumped storage scheme has a remote outfall location, away from the dam, that will evacuate the reservoir if needed. An auxiliary spillway was sized to account for the PMF storm over the small watershed of the reservoir, along with full operation of the pumps to prevent overtopping.

278 Senior Project Engineer, Geo-Engineering Department – Dams, Levees, and Reservoirs Practice, Black & Veatch Water, Philadelphia, PA 19106, [email protected] 279 Regional Practice Leader, Geo-Engineering Department – Dams, Levees, and Reservoirs Practice, Black & Veatch Water, Gaithersburg, MD 20879, [email protected]

205 NOTES

206 CONSTRUCTION OF A CUT-OFF WALL FOR EXISTING TAILINGS IN WARM PERMAFROST IN ALASKA

Franz-Werner Gerressen280 Brian W. Wilson, P.Eng.281

ABSTRACT

Diaphragm walls are generally known as underground structural elements most commonly used for retention systems and permanent foundation walls. They can of course also be used to construct cut-off walls and act as deep groundwater barriers.

This paper describes the construction method and sequence of activities required for the construction of cut-off-walls using the trench cutter system, including a discussion ofthe equipment required to execute such works. In addition the paper describes the work involved in the design and construction of a cut-off wall along the Back Dam of the existing tailings impoundment at Red Dog Mine, Alaska. The completed cut-off wall was about 5,000 ft long and up to 150 ft deep.

Red Dog Mine is situated in northwestern Alaska in an area of warm permafrost and high potential seismic activity. Proposed increases in capacity for the tailings pond required raising the back dam and necessitated construction of a cut-off to protect the adjacent watershed. Design incorporated a detailed assessment of the site hydrogeology and an assessment of rock jointing to define the final depth of the wall along the alignment. Cut- off wall construction required the use of plastic concrete backfill to address concerns associated with potential cracking of the wall due to settlement of the dam, and ground movements during seismic activity.

About 4,000 ft² of cut-off wall was constructed in 2007 to evaluate the performance of the cutter heads, the slurry transport systems, and the mix design, allowing appropriate planning for future seasons. Cut-off wall construction continued in 2008 and 2009 with two 12-hour shifts operating from May to October in each year. Approximately 148,000 ft² of wall was completed in 2008 and 150,000 ft² in 2009. The balance of the wall was completed in 2010.

280 Director Method Development, BAUER Maschinen, Germany 281 Principal – Project Development, Golder Construction Inc., Canada

207 NOTES

208 MITIGATING RISK WHEN DRILLING AT THE TOE OF A DAM

Cari R. Beenenga, P.E.282 Edward J. Barben, P.E.283

ABSTRACT

The occurrence of artesian conditions at the toe of existing dams is common due to the reservoir pool charging an underlying aquifer while the dam itself acts as a confining layer. The volume and velocity of artesian flow varies depending on the reservoir head, distance downstream and subsurface geology. Boreholes drilled at the toe of a dam can, in effect, shorten the seepage path and create an open conduit which can lead to piping and erosion of embankment or foundation materials causing irreversible damage. Being prepared for artesian conditions prior to drilling is necessary to prevent potential dam failure.

This paper will present three case studies where artesian conditions were encountered and quickly remedied before detrimental erosion occurred. The drilling conducted at each dam herein was completed as part of a subsurface investigation prior to structure rehabilitation. In each scenario, the purpose of the boreholes drilled at or near the toe was for the construction and installation of instrumentation used to collect data pertinent for the rehabilitation design.

Each of the three case studies are unique in that the severity of the artesian flow varied and, as such, were uniquely remediated. As evident within this paper, a remedial technique that works for one scenario may not work for another. As a result, consideration of the need for a boring at the toe of a dam versus the risk of artesian flow is necessary. Evaluation of the existing geology, possible flow regimes, and as-built construction data must be reviewed prior to drilling such that potential remedial solutions can be premeditated should a boring at the toe be necessary. The concluding paragraphs of this paper will provide recommendations for preparation prior to drilling at the toe of a dam as well as how to assess the situation and remedial alternatives during an artesian event.

282Geotechnical Project Manager, Gannett Fleming, Inc., P.O. Box 67100, Harrisburg, PA 17106-7100, Phone: 717-763-7212 ext. 2698, [email protected] 283 Geotechnical Engineer, Gannett Fleming, Inc., P.O. Box 67100, Harrisburg, PA 17106-7100, Phone: 717-763-7212 ext. 2889, [email protected]

209 NOTES

210 PINE CREEK DAM — PHASE IV VOID INVESTIGATION AND BACKFILLING

Kathryn A. White, P.E284 D. Wade Anderson, P.E.285

ABSTRACT

Seepage in the conduit joints and along the downstream exit of the conduit has been present since the first filling of Pine Creek dam. After dewatering of the conduit in May, 2010, small amounts of sand and silt were observed within the seepage. Several investigations have been performed to investigate potential voids surrounding the conduit and to provide information for analysis and remediation measures at Pine Creek Dam. This paper focuses primarily on Phase IV Void Investigation and Backfilling. Background information and potential concerns with the dam, summary of geotechnical investigations that led to Phase IV Void Investigation and Backfilling, description of the investigation methods and field activities, and discussion of the results and conclusions drawn from the investigation are provided.

284 Lead Geotechnical Engineer, U.S. Army Engineer District, Tulsa, OK 74128, [email protected] 285 Dam Safety Center Director, U.S. Army Engineer District, Tulsa, OK 74128, [email protected]

211