United States Society on Dams
21st Century Dam Design — Advances and Adaptations
31st Annual USSD Conference San Diego, California, April 11-15, 2011 CONTENTS
Plenary Session
Managing Multiple Priorities: Raising a Dam, Operating a Reservoir, and Coordinating a System of Projects ...... 1 Kelly Rodgers and Gerald E. Reed III, San Diego County Water Authority; Rosalva Morales and Yana Balotsky, City of San Diego; Thomas O. Keller, GEI Consultants, Inc.; and Kevin N. Davis, Black & Veatch Corporation
Partnering with Project Stakeholders at the San Vicente Dam Raise...... 3 Thomas C. Haid, Parsons/Black & Veatch JV; Gerald E. Reed III, Vic Bianes and Kelly Rodgers, San Diego County Water Authority; and William A. Corn, Shimmick Construction Company
Managing Unexpected Endangered Species Issues on Bid-Ready Projects...... 5 Anita M. Hayworth, Dudek; Mary Putnam, San Diego County Water Authority; and Douglas Gettinger, Jeffrey D. Priest and Paul M. Lemons, Dudek
Planning and Cost Reduction Considerations for RCC Dam Construction...... 7 Adam Zagorski, Shimmick/Obayashi JV; and Mike Pauletto, M. Pauletto and Associates
Ten Years After the World Commission on Dams Report: Where Are We?...... 9 Manoshree Sundaram, Federal Energy Regulatory Commission
Australian Risk Approach for Assessment of Dams ...... 11 M. Barker, GHD
The Relative Health of the Dams and Reservoirs Market ...... 13 Del A. Shannon, ASI Constructors, Inc.
Design of the Dams of the Panama Canal Expansion ...... 15 Lelio Mejia, John Roadifer and Mike Forrest, URS Corporation; and Antonio Abrego and Maximiliano De Puy, Autoridad del Canal de Panama
Concrete Dams: Advances in Analysis
Myponga Dam Stability Evaluation: Modeling Stress Relaxation for Arch Dams Using Linear Finite Element Analysis ...... 17 Scott L. Jones and Guy S. Lund, URS Corporation; Bill Moler, URS Australia Pty Ltd; and Derek Moore, SA Water
iv Blue Lake Dam Left Abutment Geological Modeling for Dam Raise ...... 19 Peter C. Friz and Dan Curtis, Hatch Ltd.; James H. Rutherford, Stephen Hart and David C. Johnston, Hatch Associates Consultants, Inc.; and Dean Orbison, City and Borough of Sitka
Stability Evaluation of Leftmost Power-Unit Monoliths of the Three Gorges Dam...... 21 Haibo Liang, Gannett Fleming, Inc.; and Christopher S. Bailey and Trent L. Dreese, Gannett Fleming, Inc.
Three Predominate Failure Modes of Thin Arch Dams ...... 23 Chad Gillan and Guy S. Lund, URS Corporation; and James Weldon, Denver Water
The Investigation of a Concrete Gravity Dam in a Narrow Canyon Using 3-D Nonlinear Analysis ...... 25 Mike Knarr, Matthew Muto, Nicolas von Gersdorff and John Dong, Southern California Edison, Co.; Ziyad Duron, Harvey Mudd College; and John Yen, Southern California Edison, Co.
Folsom Dam JFP — A Tale of Strength Design, Risk Analysis, and Interagency Cooperation ...... 27 Cecily M. Nolan, Corps of Engineers
Concrete Dams: Advances in Materials and Construction
Selecting Strength Input Parameters for Structural Analysis of Aging Concrete Dams ...... 29 Timothy P. Dolen, Bureau of Reclamation
Wyaralong RCC Dam Summary & the Impact of “Low” Quality Aggregate on Design ...... 31 Colleen Stratford, SMEC; Emily Schwartz, Paul C. Rizzo Associates; Robert Montalvo, Macmahon; Ernest Schrader, Schrader Consulting; and Richard Herweynen, Entura
Limestone Filler Used as Cementitious Material in the Mix for the Largest RCC Dam in Europe: La Breña II ...... 33 Rafael Ibáñez de Aldecoa, Dragados S.A.; Gonzalo Noriega, Dragados-USA; Antonio Sandoval, acuaSur; and Miguel Sanz, Dragados S.A.
Beyond RCC — Building Quality into the San Vicente Dam Raise ...... 35 James L. Stiady,G2D Resources, LLC; Russell Grant, Kleinfelder, Inc.; David Ribble, Parsons/Black & Veatch JV; and Wade Griffis, San Diego County Water Authority
v Directional Drilling for High Capacity Anchors at Bluestone Dam ...... 37 Mark J. Rothbauer and Jeff R. Hopple, Brayman Construction Corporation
Estimated Shear Strength of Shear Keys and Bonded Joints in Concrete Dams ....39 Dan D. Curtis, Hatch Renewable Power
New Materials and Technologies for Leakage Sealing Without Affecting Operation — High Pressure Resins Injections ...... 41 A. Gonzalo, HCC; J. Alonso, ENDESA; F. Vazquez, EMASESA; and A. Vaquero, HCC
Hydraulics and Hydrology I
Penstock Scour Formation at Bluestone Dam ...... 43 E.F.R. Bollaert, AquaVision Engineering Ltd.
Designing the Folsom Auxiliary Spillway Piers Using LS-DYNA® Time-History Results ...... 45 Eric Kennedy, Corps of Engineers
Large-Eddy Simulation of Flow Over a Low-Head Dam ...... 47 Piroz Zamankhan, University of Iceland
Sensitivities of Channel Geometry Compared to Modeling Assumptions in Dam Failure Analysis ...... 49 Joey M. Windham, Corps of Engineers
Dam Failure System Modeling in the Muskingum Watershed — Beach City Dam ...51 Edward L. Stowasser, Corps of Engineers
Unsteady Flow Simulations and Inundation Mapping for the Missouri River Main-Stem Dam System ...... 53 Thomas Gorman, Curtis Miller, Lowell Blankers, Laurel Hamilton, Neil Vohl and Megan Splattstoesser, Corps of Engineers
Modeling Dam Failures of the Rancocas Creek Watershed in Southern New Jersey ...... 55 Arthur C. Miller, AECOM; Dennis Johnson, Juniata College; and Norman Folmar, Pennsylvania State University
Development of Computational Methodology to Assess Erosion Damage in Dam Spillways ...... 57 B. Dasgupta, D. Basu, K. Das and R. Green, Southwest Research Institute
Economic Analysis of Privatized Hydroelectric Power Plant Projects in Turkey ....59 Murat Gunduz, Middle East Technical University; and Haci Bayram Sahin, GESTAS Construction Inc. Co.
vi Post-Tensioned Trunnion Anchor Rod Testing, West Point Dam and R.F. Henry Dam...... 61 George V. Poiroux, Corps of Engineers
Intelligent Flow Control After Load Rejection at the Juniper Ridge Hydroelectric Power Generation Project, Bend, Oregon ...... 63 Alden C. Robinson and Z. (Joe) Zhao, Sunrise Engineering, Inc.
Foundations
Safe Grouting Pressures for Dam Remediation ...... 65 Jeffrey A. Schaefer, David B. Paul and Douglas D. Boyer, Corps of Engineers
Rock Grouting for Dams and the Need to Fight Regressive Thinking ...... 67 Donald A. Bruce, Geosystems, L.P.
Evaluating the Risks of an Internal Erosion Failure at Amistad Dam...... 69 William O. Engemoen, Bureau of Reclamation; Randel Mead, Corps of Engineers; and Luis Hernandez, International Boundary and Water Commission
Geologic Data and Risk Assessment; Improving Geologic Thinking and Products ...71 Peter T. Shaffner, Corps of Engineers
Assessing the Potential for Seepage Barrier Defects to Propagate into Seepage Erosion Mechanisms ...... 73 Ryan G. Van Leuven and John D. Rice, Utah State University
Reliable Seepage Control by Plastic Concrete Cut-off Walls ...... 75 Peter E. Banzhaf and Eckart Colmorgen, Bauer Spezialtiefbau GmbH
Assessment and Analysis of Wyaralong Dam Foundation ...... 77 Jared Deible, Paul C. Rizzo Associates; Richard Herweynen, Entura; and John Ager, SMEC Australia
Navigation Lock Foundation Design in Complex Karst Geology at Chickamauga Dam...... 79 Mark S. Elson and Juan Payne, Corps of Engineers; and Dewayne Ponds, ARCADIS US, Inc.
Construction and Rehabilitation
Howard A Hanson Dam Right Abutment Seepage Fast Track to Interim and Final Repairs ...... 81 Richard E. Smith, Robert E. Romocki and Dennis A. Fischer, Corps of Engineers
vii Cement Bentonite Slurry Wall Strength — Tuttle Creek Dam Seismic Remediation ...... 83 Amod K. Koirala, Glen M. Bellew, John C. Dillon and David L. Mathews, Corps of Engineers
Construction of Cut-Off Wall by Low-Headroom-Cutter Inside Dam Tunnel in China ...... 85 Wolfgang G. Brunner, BAUER Maschinen GmbH; Arthur Bi and William Chang, BAUER Technologies Ltd.; and Dung Feng Zong, China Water Group
Wanapum Dam Future Unit Infill Project ...... 87 Jim Rutherford, Hatch Associates Consultants; Cliff Stump, Barnard Construction, Inc.; Gary Mass, Concrete Engineer & Consultant; David Lehto, Knight Construction and Supply; and Randy Nash, Grant County Public Utility District No. 2
Falls Dam Stoney Gate Repairs ...... 89 Mark J. Gross, Alcoa Power Generating Inc.; and Paul F. Shiers, Anthony W. Plizga and Jesse Kropelnicki, PB Americas, Inc.; and John C. Lyon, Federal Energy Regulatory Commission
Remediation Measures Implemented to Resolve Gate Operation Difficulties Related to Spillway Deck Concrete Expansion ...... 91 Mark J. Gross, Alcoa Power Generating Inc.; Jacob Vozel, Allegheny Energy Engineering & Construction, and Bryce Mochrie and Stefan Schadinger,PB Power; and Paul F. Shiers, PB Americas, Inc.
Cheesman Dam Outlet Works Renovation — Underwater Construction Engineering...... 93 Jeff Martin, Denver Water; and Gordon Harbison, Krech Ojard & Associates
Guidelines for Assessing Sediment-Related Effects of Dam Removal ...... 95 Timothy J. Randle, Jennifer A. Bountry and Blair P. Greimann, Bureau of Reclamation
Short- and Long-Term Impacts of Sediment Erosion Following Dam Removal: Sediment and Nutrient Loading ...... 97 John R. Shuman, Johnson, Mirmiran and Thompson
Sediment Impacts from the Removal of Savage Rapids Dam ...... 99 Jennifer A. Bountry, Yong G. Lai and Timothy J. Randle, Bureau of Reclamation
Remove or Reinforce: Design Alternatives to Meet Dam Safety and Fish Passage Requirements at San Clemente Dam ...... 101 Tom Hepler and Blair Greimann, Bureau of Reclamation; Trish Chapman, State Coastal Conservancy; and Jeffery Szytel, Water Systems Consulting, Inc.
viii Lake Townsend Dam Replacement — Construction Update, Greensboro, NC ....103 Robert Cannon, Tillman Marshall, Gerald Robblee, Frederic Snider and Jerry Gardner, Schnabel Engineering; Melinda King and Allan Williams, City of Greensboro; and Andrew R. Downs, Crowder Construction Company
Emergency Response and Rehabilitation of Spillway Damage Caused by a Mother’s Day Storm...... 105 Stephen L. Whiteside, Tyler C. Dunn and Aaron J. Rubin, CDM; and Richard Dawe, Lynn Water & Sewer Commission
Seepage Modeling for Evaluation of Dewatering Efforts for Construction of the Coachella Canal Lining Project ...... 107 Geraldo R. Iglesia,G2D Resources, LLC; Christopher M. Dull, R.W. Beck, Inc.; Kenneth A. Steele, Consultant; and Halla Razak, San Diego County Water Authority
Reliability Analysis of Side Slopes for the All-American Canal Lining Project ....109 Geraldo R. Iglesia,G2D Resources; Christopher M. Dull, R.W. Beck, Inc.; Kenneth A. Steele, Consultant; and Kathy L. Schuler, San Diego County Water Authority
Design and Construction of a Sub-Liner Drain System for the Ludington Pumped Storage Plant ...... 111 Gerald Robblee, Edward Billington, Robert Cannon, Gary Rogers, Donald Basinger, Frederic Snider and Alex Rutledge, Schnabel Engineering; and David Battige, Consumers Energy
Saving Institutional Memory and the Extraordinary Cost Effectiveness of Project Databases ...... 113 Donald A. Bruce, Geosystems, L.P
Stress Analysis of Proposed Raising of the Blue Lake Arch Dam ...... 115 D. Curtis and F. Feng; Hatch Ltd.; S. Hart, Hatch Associates Consultants, Inc.; and D. Orbison, City and Borough of Sitka
Rebuilding the Silver Lake Dam ...... 117 Jeffrey M. Bair, Black & Veatch Corporation; Benjamin K. Ferguson, Paul C. Rizzo Associates; Jeffrey E. Krueger, Integrys Business Support, LLC; and Robert J. Meyers, Upper Peninsula Power Company
Investigating and Rehabilitating a 100-Year Old Earthen Embankment Dam in Southeastern Massachusetts ...... 119 Stan S. Sadkowski, III, Vernon R. Kokosa and Luke D. Norton, Sanborn, Head & Associates, Inc., George Rogers, A.D. Makepeace Company; and Alan Swieder, McNamara/Salvia, Inc.
ix Lessons Learned at the Taum Sauk Rebuild ...... 121 Paul C. Rizzo and Carl Rizzo, Paul C. Rizzo Associates, Inc.; and John Bowen, ASI Constructors, Inc.
Stability Issues at Intake UD, Hong Kong ...... 123 A. Rowland, C. F. Wan and J. Dominic Molyneux, Black & Veatch Corporation
Embankment Dams
Performance of Flood-Tested Soil-Cement Protected Levees ...... 125 Kenneth D. Hansen, Consultant; Dennis L. Richards, Ayres Associates; and Mark E. Krebs, Pacific Advanced Civil Engineering, Inc.
Gibe III: A Zigzag Geomembrane Core for a Rockfill Cofferdam in Ethiopia .....127 G. Pietrangeli and A. Pietrangeli, Studio Ing.; A. Scuero and G. Vaschetti, Carpitech; and J. Wilkes, Carpi USA Inc.
Design and Construction of Nemiscau-1 Dam, the First Asphalt Core Rockfill Dam in North America ...... 129 Vlad Alicescu and Jean-Pierre Tournier, Hydro-Québec; Pierre Vannobel, SEBJ; and Véronique Moore, Groupe Qualitas Inc.
Central Filter Drain Installation for the Rehabilitation of Buckeye FRS No. 1 ....131 Sam Sherman, Flood Control District of Maricopa County; and Lawrence Hansen, AMEC Earth & Environmental
First Introduction of Greg Hanson’s "Jet Erosion Test" in Europe: Return on Experience after 2 Years of Testing...... 133 Patrick Pinettes, geophyConsult SAS; Jean-Robert Courivaud and Jean-Jacques Fry, eDF-CIH; and Fabienne Mercier and Stéphane Bonelli, Cemagref UR Ouvrages hydrauliques et hydrologie
Application of ‘A Unified Method for Estimating Probabilities of Failure of Embankment Dams by Internal Erosion and Piping’—AUKPerspective ...... 135 M. Eddleston, MWH; P. Rigby, Haweswater House; R. Margrett and P. J. Mason, MWH; K. D. Gardiner, United Utilities Water PLC; and J. Cyganiewicz, Cyganiewicz Geotechnical, LLC
Pine Creek Dam — Issues, Investigations, and Interim Measures ...... 137 D. Wade Anderson and Kathryn A. White, Corps of Engineers
x Safety, Security and Emergency Response
Modeling, Mapping & Consequence Production Center / Illustrated Guide to MMC Inundation Mapping Graphic Specification ...... 139 Joey M. Windham and Will Breitkreutz, Corps of Engineers
USACE Modeling, Mapping, & Consequence Center — Bluestone Dam Failure Analysis & Lessons Learned ...... 141 Edward L. Stowasser, Corps of Engineers
Proactive Ownership of the Pedlar Dam Leads to Timely and Cost-Efficient Solutions with Changing Regulations...... 143 Dennis Hogan and Greg Zamensky, Black & Veatch Corporation
Approaches to Estimating Consequences Due to Levee Failure, St Paul Levee System Beta Test ...... 145 Corby Lewis, Patrick Foley, Mitch Laird, Kari Layman, Jeff McGrath and Andrew Sander, Corps of Engineers
A Consistent Approach for Vulnerability Assessment of Dams...... 147 Yazmin Seda-Sanabria, Corps of Engineers; M. Anthony Fainberg, Institute for Defense Analyses; and Enrique E. Matheu, U.S. Department of Homeland Security
Development of a Practical Tabletop Exercise Support Tool ...... 149 Michael Bowen, Robert C. Hughes, Alan Patterson and Enrique E. Matheu, U.S. Department of Homeland Security
Emergency Action Planning — Inundation Map Updates Using a Geographic Information System ...... 151 Kareem A. Bynoe, PB Americas, Inc., Ray Barham, Alcoa Power Generating Inc., Michael Woodruff, Federal Energy Regulatory Commission; and Shirley Williamson and Paul F. Shiers, PB Americas, Inc.
21st Century Dam Safety Programs in the U.S. Department of the Interior ...... 153 M. E. Baker, Bureau of Reclamation
Quality and Quantity, It Can Be Done! NC NRCS Dam Assessments ...... 155 Everett L. Litton, Greg Zamensky and Dennis Hogan, Black & Veatch Corporation
Levee Safety and Tolerable Risk — Implications for Shared Risk, Responsibility, and Accountability ...... 157 Dale F. Munger, Corps of Engineers; David S. Bowles, Utah State University and RAC Engineers & Economists; and Darryl W. Davis, Brian K. Harper and David A. Moser, Corps of Engineers
xi Seismic Fragility of Mühleberg Dam Using Nonlinear Analysis with Latin Hypercube Simulation...... 159 Yusof Ghanaat, Quest Structures, Inc.; Philip S. Hashimoto, Simpson Gumpertz & Heger, Inc.; Olivier Zuchuat, BKW FMB Energie AG; and Robert P. Kennedy, RPK/Structural Mechanics Consulting, Inc.
Reservoir Safety Management in Hong Kong...... 161 Chi-fai Wan, Black & Veatch Australia Pty Ltd.; and Siu-lung Li, Water Supplies Department of Hong Kong
Levees
Lower Missouri River Basin Dam and Levee Flood Fight Lessons Learned...... 163 Willem H. A. Helms, Eugene J. Kneuvean, Stephen J. Spaulding, William B. Empson, Jared D. Mewmaw and Rexford G. Goodnight, Corps of Engineers
Hydrologic and Hydraulic Analyses for FEMA Levee Certification in San Bernardino County, California ...... 165 Daniela Todesco, Dragoslav Stefanovic and Darren Bertrand, WEST Consultants, Inc.; and Mark Seits and Yunjing Zhang, HDR Engineering, Inc.
Assessment of Site Variability and Geotechnical Levee Hazard with Flood Frequency and Repair Options ...... 167 Christopher B. Groves, Hollie L. Ellis and N. Kyle Tabor, Shannon & Wilson
Transient Analysis — Case History of Use and Impacts ...... 169 Michael L. Bachand, CDM; Michael Stuer, Lowell Regional Wastewater Utility; and James S. Drake, CDM
Integrating Dam Inspection Skills into Safety Evaluations for Levees and Canals ...... 171 Laura LaRiviere and Rebecca Allen, Kleinfelder, Inc.
Balancing Nature, Society and the Climate
Improving Fish Passage and Public Safety at Low Head Dams ...... 173 Paul G. Schweiger, Gannett Fleming, Inc.; Luther Aadland, Minnesota Department of Natural Resources; and Don Roarabaugh, Eric Neast and Chad Hoover, Gannett Fleming, Inc.
Providing Fish Passage at the Middle Fork Nooksack River Diversion Dam .....175 Lawrence M. Magura, Black & Veatch Corporation; and Clare Fogelsong, City of Bellingham
Methodology for Hydropower Certification in Italy and Slovenia ...... 177 N. Smolar-Zvanut, Institute for Water of the Republic of Slovenia; A. Goltara, Italian Centre for River Restoration; and G. Conte, Ambiente Italia Srl
xii Collaboration on Climate Change Analysis in the Pacific Northwest ...... 179 James D. Barton, Corps of Engineers
Earthquakes
Deformations of a Zoned Rockfill Dam from a Liquefiable Thin Foundation Layer Subjected to Earthquake Shaking ...... 181 Mahmood Seid-Karbasi and Upul Atukorala, Golder Associates Ltd
Several Observations on Advanced Analyses with Liquefiable Materials ...... 183 Michael L. Beaty, Beaty Engineering LLC; and Vlad G. Perlea, Corps of Engineers
Hebgen Dam — A History of Earthquake Hazards and Analyses ...... 185 Steve Benson, Tom O’Brien and Bonnie Witek, URS Energy and Construction; and Ethan Dawson, URS Infrastructure and Environment
Seismic Analyses and Potential Failure Modes of the Intake Tower and Borel Conduit at Lake Isabella Auxiliary Dam ...... 187 Said Salah-Mars, Mourad Attalla and Erik Newman, URS Corporation; Chung Wong, David Serafini and Michael Ma, Corps of Engineers; Yusof Ghanaat, Quest Structures, Inc.; Faiz Makdisi, AMEC Geomatrix, Inc.; and Keith Ferguson, HDR, Inc.
Near Failure of the All American Canal in Southern California Due to a 7.2 Magnitude Earthquake in April, 2010 ...... 189 Bob Dewey and Dave Palumbo, Bureau of Reclamation
Earthquake Response of Rockfill Dam with Asymmetric Plan Geometry of Upstream and Downstream Slope with Respect to Dam Axis ...... 191 Ik-Soo Ha, Korea Water Resources Corporation
Behavior Characteristics of Composite Dam Using Centrifuge ...... 193 Jeong-Yeul Lim and Ik-Soo Ha, Korea Water Resources Corporation
Monitoring
San Roque Multipurpose Project — Performance Monitoring Assessment ...... 195 Michael Pavone, Joseph Ehasz, Stephen Benson and Bonnie Witek, URS Energy and Construction
Automation of the Long-Term Technical Monitoring of the O balt Concrete Dam ...... 197 Pavel vanut, Slovenian National Building and Civil Engineering Institute
xiii Web-Based Real-Time Monitoring at Perris Dam Using In-Place Inclinometers and Piezometers with an Automatic Notification System ...... 199 John Lemke, Geodaq, Inc.; Mike Driller, California Department of Water Resources; and Dan Wilson, University of California, Davis
Assessment Method for Routine Dam Safety Monitoring Programs ...... 201 Jay N. Stateler, Bureau of Reclamation
Nondestructive Evaluation of Seepage in an Earthen Dam ...... 203 John Stoessel and Matthew Pruchnik, Southern California Edison; and Paul Rollins, Willowstick
Fiber Optics Based Monitoring of Levees and Embankment Dams ...... 205 Jean-Robert Courivaud, EDF; Patrick Pinettes and Cyril Guidoux, geophyConsult; and Jean-Jacques Fry and Yves-Laurent Beck, EDF
Paradigm Shifts in Monitoring Levees and Earthen Dams: Distributed Fiber Optic Monitoring Systems...... 207 Daniele Inaudi, Smartec SA; and Joseph Church, Roctest, Inc.
Rogue Piezometers ...... 209 Douglas A. Crum, Corps of Engineers
Hydrology and Hydraulics II
Performance of Dams and Spillways — 2009 Georgia Floods...... 211 Randall P. Bass, James R. Crowder and Joseph S. Monroe, Schnabel Engineering
Using Multiple Methods to Improve Hydrologic Hazard Estimates for Dam Safety ...... 213 Frank Dworak, Bureau of Reclamation
Development of a Restricted Reservoir Operating Plan at West Point Dam, Georgia ...... 215 Kevin Fagot, WEST Consultants, Inc.; Jamie M. Bartel, CDM Federal Programs; Andy Ashley, Corps of Engineers; and Michael Schmidt, CDM
Evolving Design Approaches and Considerations for Labyrinth Spillways ...... 217 Greg Paxson, Dave Campbell and Joe Monroe, Schnabel Engineering
The Design and Analysis of Labyrinth Weirs ...... 219 B. M. Crookston and B. P. Tullis, Utah State University
Upgrading Lake Holiday Spillway Using a Labyrinth Weir ...... 221 John Ackers, Felicity Bennett and Greg Zamensky, Black & Veatch Corporation
xiv Piano Key Weir Hydraulics ...... 223 Ricky M. Anderson and Blake P. Tullis, Utah State University
San Vicente Dam
Structural Design for San Vicente Dam Raise ...... 225 Glenn S. Tarbox, Michael F. Rogers, Vic Iso-Ahola and Bashar Sudah, MWH Americas, Inc., Jim Zhou, San Diego County Water Authority; and Mark Schultz, California Department of Water Resources
Geologic Characterizations of San Vicente Dam Raise ...... 227 David L. Schug, URS Corporation; Nicola Kavanagh, San Diego County Water Authority; and Michael Higgins, URS Corporation
Geotechnical Basis of Design for the San Vicente Dam Raise ...... 229 Leo D. Handfelt, Kelly C. Giesing and Melissa Cox, URS Corporation; and Jim Zhou, San Diego County Water Authority
Seismic Hazard Evaluation for Design of San Vicente Dam Raise...... 231 Leo D. Handfelt and Ivan Wong, URS Corporation; and Nicola Kavanagh, San Diego County Water Authority
Application of Customized Construction-Cost Index on the San Vicente Dam Raise Project ...... 233 Geraldo R. Iglesia,G2D Resources; and P. Timothy H. Dyer and Aaron S. Rouch, San Diego County Water Authority
Staying Dry — Cofferdam Challenges on the San Vicente Dam Raise Project ....235 Wayne O. Mac Donell, Ben C. Gerwick, Inc.; Aaron Rietveld, Barnard Construction Company, Inc.; and Gary Olvera, San Diego County Water Authority
xv MANAGING MULTIPLE PRIORITIES: RAISING A DAM, OPERATING A RESERVOIR, AND COORDINATING A SYSTEM OF PROJECTS
Kelly Rodgers, P.E.1 Gerald E. Reed III P.E.2 Rosalva Morales 3 Yana Balotsky 4 Thomas O. Keller, P.E., G.E.5 Kevin N. Davis, P.E. 6
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 San Diego region cross several major fault lines. In 1998, the Water Authority’s Board of Directors approved the Emergency Storage Project (ESP). The purpose of this $1.5 billion project is to increase local storage and provide a more flexible conveyance system to address the risk associated with disruption of imported water deliveries. 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 concrete gravity dam by 117 feet to increase reservoir storage capacity by 152,000 acre-feet. The City of San Diego (City) owns and operates the San Vicente Dam and the Water Authority will be raising it as part of the SVDR Project. It 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 the region’s history. Raising a dam poses many challenges from planning to design and construction. Also, during dam raise construction, the dam and reservoir must remain fully operational to supply water to the City’s customers. Finally, there are other Water Authority projects being constructed simultaneously at the San Vicente site, necessitating close inter-project coordination.
1 Senior Engineer, San Diego County Water Authority, 4677 Overland Avenue, San Diego, California 92123-1233, [email protected]. 2 Engineering Manager, San Diego County Water Authority, 4677 Overland Avenue, San Diego, California 92123-1233, [email protected]. 3 Associate Engineer - Civil, City of San Diego, 2797 Caminito Chollas, San Diego, California 92105- 5097, [email protected] 4 Associate Engineer - Civil, City of San Diego, 2797 Caminito Chollas, San Diego, California 92105- 5097, [email protected] 5 Vice President, GEI Consultants, Inc., 2141 Palomar Airport Road, Suite 160, Carlsbad, California 92011-1463, [email protected]. 6 Project Director, Black & Veatch, 300 Rancheros Dr # 250, San Marcos, California 92069-2969, [email protected]
1 NOTES
2 PARTNERING WITH PROJECT STAKEHOLDERS AT THE SAN VICENTE DAM RAISE
Thomas C. Haid, P.E., CCM7 Gerald E. Reed, III, P.E.8 Vic Bianes, P.E.9 Kelly Rodgers, P.E.10 William A. Corn 11
ABSTRACT
The San Vicente Dam in Lakeside, California, is being raised to increase water storage for the region. The existing 220-foot-high concrete gravity dam will be raised by 117 feet using roller-compacted concrete (RCC), thereby expanding the usable reservoir capacity approximately 152,000 acre-feet. The existing San Vicente Dam is owned and operated by the City of San Diego (City) for water supply and has marina facilities and a boat ramp providing public access to the water surface. Following the dam raise, the San Diego County Water Authority (Water Authority) and City will jointly use the expanded reservoir for water supply. In addition to the City, Water Authority, and public stakeholders, the key regulatory stakeholder is State of California, Department of Water Resources, Division of Safety of Dams (DSOD), which provides approvals throughout the planning, design, and construction processes. The project is being completed as a series of competitively bid public works construction contracts, and the multiple engineering and construction companies working for the Water Authority comprise another set of project stakeholders, which results in additional challenges in coordinating the multiple construction contracts and project interfaces at the site. Uniting the many diverse project stakeholders into a cohesive team involved using a partnering process, which included periodic formal meetings as well as applying the principles of partnering on a daily basis. The various ways partnering is used to unite the multiple stakeholders is discussed.
7Project Manager, Parsons/Black & Veatch JV, 110 West “A” Street, Suite 1050, San Diego, CA 92101, Email: [email protected] 8Engineering Manager, Project Management Group, San Diego County Water Authority, 4677 Overland Avenue, San Diego, CA 92123, Email: [email protected] 9Manager, Design Group, San Diego County Water Authority, 4677 Overland Avenue, San Diego, CA 92123, Email: [email protected] 10Senior Engineer, Project Management Group, San Diego County Water Authority, 4677 Overland Avenue, San Diego, CA 92123, Email: [email protected] 11 Operations Manager, Shimmick Construction Company, 16481 Scientific Way, Irvine, CA 92618, Email: [email protected]
3 NOTES
4 MANAGING UNEXPECTED ENDANGERED SPECIES ISSUES ON BID-READY PROJECTS
Anita M. Hayworth, Ph.D.12 Mary Putnam13 Douglas Gettinger14 Jeffrey D. Priest15 Paul M. Lemons16
ABSTRACT
Dam construction and subsequent reservoir inundation may affect sensitive plants and wildlife, thus requiring rigorous environmental permitting. Even with permits in hand, routine surveys may result in the unexpected discovery of sensitive species during project implementation. For dam construction projects, delays or work stoppages to allow for agency consultation and issuance of amended permits are problematic and potentially expensive.
The San Vicente Dam Raise (SVDR) Project entails construction activity with habitat impacts. Initial surveys indicated three federally listed endangered species were present. A Biological Opinion for these species was issued as part of the Endangered Species Act Section 7 consultation between the U.S. Fish & Wildlife Service (USFWS) and the U.S. Army Corps of Engineers (Corps). However, during preconstruction surveys, a species not addressed with the permits, the federally listed endangered Quino Checkerspot Butterfly (Euphydryas editha quino) was unexpectedly observed on site.
To avoid delays and address the species, the Water Authority and its consultant (Dudek) requested informal consultation with the agencies. Biologists were mobilized and Dudek used a USFWS model to estimate “occupied Quino Checkerspot Butterfly habitat”. The Water Authority team worked quickly and cooperatively with the agencies to conduct a site visit, prepare graphics, provide the model results, and prepare documents for use in permit amendments. Based on this information, impacts were calculated, mitigation was negotiated, and the amended Corps Section 404 permit and Biological Opinion were issued. The formal consultation process was completed in less than three weeks and resulted in no change in the project schedule.
12Senior Biologist/Senior Project Manager, Dudek, 605 Third Street, Encinitas, CA 92024, [email protected] 2 Project Manager, San Diego County Water Authority, 4677 Overland Avenue, San Diego, CA 92123, [email protected] 14Restoration Specialist, Dudek, 605 Third Street, Encinitas, CA 92024, [email protected] 15 Biologist, Dudek, 605 Third Street, Encinitas, CA 92024, [email protected] 16 Biologist, Dudek, 605 Third Street, Encinitas, CA 92024, [email protected]
5 NOTES
6 PLANNING AND COST REDUCTION CONSIDERATIONS FOR RCC DAM CONSTRUCTION
Adam Zagorski17 Mike Pauletto18
INTRODUCTION
The San Vicente Dam Raise Project is currently being constructed for the San Diego County Water Authority (SDCWA) and the City of San Diego in the hills east of San Diego near Lakeside, California by Shimmick-Obayashi Joint Venture. The City of San Diego is the owner of the dam and original reservoir storage, while SDCWA will take ownership of the incremental storage capacity created from the raised dam. The purpose of the project is to raise the existing dam 117 ft and increase the reservoir storage capacity from 90,000 acre ft to 242,000 acre ft (see figure 1). In addition to the main dam raise portion, there is construction of a saddle dam in a topographic low point in the reservoir rim just to the west of the dam. SDCWA is utilizing the San Vicente project as a major feature in its development of an “Emergency Storage Project” (ESP) and part of its ”Carryover Storage Project” (CSP), both of which will increase the operational flexibility of the water delivery system in the San Diego region. The contract awarded for the raised-dam portion of the construction of the San Vicente Dam Raise is the third (Package 3) in a series of packages awarded to perform the construction of all facilities, including exploratory quarry and test fill programs as well as foundation excavation and the main dam raise structure. This paper will review the planning and scheduling processes performed after the award of Package 3 which help to ensure that a safe, high quality, low cost project can be attained.
17 Shimmick Construction Company, [email protected] 18 M. Pauletto and Associates LLC
7 NOTES
8 TEN YEARS AFTER THE WORLD COMMISSION ON DAMS’ REPORT: WHERE ARE WE?
Manoshree Sundaram, P.E.19
ABSTRACT
Ten years after the publication of the World Commission on Dams’ (WCD) report entitled Dams and Development: Report of the World Commission on Dams, significant progress has been made to incorporate the WCD’s core values of equity, efficiency, sustainability, participatory decision-making, and accountability in the development of dams and water resource projects to address the world’s current and future water needs. Many entities have incorporated these core values to address a variety of challenges including sustainability and climate change, and a widely recognized obstruction to progress – corruption. However, there is still significant progress to be made to successfully develop sustainable dam and water resource projects in a socio- economically, geo-politically, and environmentally responsible manner.
The International Hydropower Association published the final version of their Hydropower Sustainability Assessment Protocol in late 2010. The U.S. Bureau of Reclamation issued its strategy to address water resource needs for the region while accounting for the effects of climate change. Along these lines, during the Institution of Civil Engineers’ (ICE) 2010 convention, the Protocol for Engineering a Sustainable Future for the Planet originally signed in 2006 by ICE, the Canadian Society of Civil Engineering, and the American Society of Civil Engineers was updated. Although many challenges face the dams and water resources community, it is evident that significant progress has been made towards responsible and sustainable projects around the world. Projects in the U.S., Africa, Nepal, and Canada, among other countries, have been successfully planned, designed, constructed, and maintained while exemplifying the WCD guidelines. These examples should provide inspiration to continue the development of innovative solutions to the challenges facing the dams and water community. This paper reviews some achievements by the global dam and water resource community to advance responsible projects which embody the core values established by the WCD ten years ago and provides suggestions to address the continually evolving world water needs in a sustainable, yet responsible manner.
19 Civil Engineer, Federal Energy Regulatory Commission, Chicago Regional Office, 230 South Dearborn, Room 3130, Chicago, IL 60604, [email protected]
9 NOTES
10 AUSTRALIAN RISK APPROACH FOR ASSESSMENT OF DAMS
M. Barker20
ABSTRACT
The Australian National Committee on Large Dams (“ANCOLD”) produced the Guidelines on Risk Assessment (“Guidelines”) in October 2003. The possible roles for risk assessment in reaching a conclusion on the safety of dams were given in the Guidelines as:
(a) an enhancement to the traditional method; (b) an alternative to the traditional approach; and (c) a sole basis for decision making.
At the time of the Guideline publication, ANCOLD only supported the first of these roles for important and conclusive decision making regarding dam safety. However, current use of the guidelines and application of risk assessment techniques have evolved and some of the States within Australia have accepted the second of the above, i.e. the use of both the traditional and risk assessment techniques for the safety regulation of dams.
ANCOLD is currently in the process of developing supporting information for the Guidelines in order to:
1) Re-emphasise practice that is important but generally not being followed; 2) Provide explanatory notes to update practice or enhance guidance already provided; and 3) Introduce new concepts that should be included in current practice.
The purpose of this paper (and conference presentation) is to provide an overview of the practices being followed within the Australian States with regard to the application of risk assessment in dam safety management and to provide information as to the status of the ANCOLD Guidelines on Risk Assessment supporting information.
20 Principal Engineer Dams, GHD, Brisbane, Australia, [email protected]
11 NOTES
12 THE RELATIVE HEALTH OF THE DAMS AND RESERVOIRS MARKET
Del A. Shannon, PE21
ABSTRACT
The relative health of the dams and reservoirs market is a subject not widely discussed and poorly understood. While recently there has been a notable increase in dam projects (and more recently levee projects), specific tracking of this market is not currently being published or openly discussed. Forecasting of future trends of the market, beyond very general estimates as to the required capital costs to remediate existing deficient dams, does not exist and there is virtually no data on the future market for dams. However, there is some data available that may be used to review the past performance of this market and anticipate future trends. Beginning in 1998, and continuing each year after, the Engineering News Record (ENR) published the top 10 firms (revenues) for specific market sectors. By compiling and analyzing this data specific trends become visible. In 1998 the ENR reported the combined revenues of the top 10 firms in the dams and reservoirs category were reported as $97.1 million. In 2010 the combined revenues of the top 10 firms in this same category were reported as $753.1 million; an increase of 675% in 13 years. This is a 20% average annual increase in total revenues.
While the accuracy of this data could, and should, be debated it serves as a relative barometer to the overall health of the dams and reservoirs market. This paper will further evaluate the ENR data, and other published data, to show historic market trends, and will also attempt to forecast future trends in the dams and reservoirs market.
21 Design Manager, ASI Constructors, Inc., 1850 E. Platteville Blvd., Pueblo West, CO 81007, [email protected]
13 NOTES
14 DESIGN OF THE DAMS OF THE PANAMA CANAL EXPANSION
Lelio Mejia22 John Roadifer23 Mike Forrest24 Antonio Abrego25 Maximiliano De Puy26
ABSTRACT
Together with new Post-Panamax locks at the Pacific entrance, the Panama Canal Expansion will include a 6.7-km-long channel to provide navigation access from the new locks to the existing Gaillard Cut section of the Canal. Two dams with a combined length of nearly 4 km and up to about 30 m high, known as the Borinquen Dams 1E and 2E, are needed to form the new channel’s eastern bank. Two additional dams, referred to as the Borinquen Dams 1W and 2W and totaling 1.4 km in length, are necessary along the western bank.
The dams will retain Gatun Lake, the main waterway of the Panama Canal. Therefore, they are critical components of the Canal expansion and must be built to withstand their design loads with a high level of reliability. Design of the dams posed multiple challenges including: 1) variable foundation conditions with occasional weak features, 2) sole availability of residual soils derived from rock weathering as impervious materials for a dam core, 3) a wet tropical climate with a short dry season, 4) a high seismic hazard, including possible surface fault rupture across the dam foundations, and 5) potential for grounding of Post-Panamax-size ships against the inboard face of the dams.
This paper describes the dams of the Panama Canal Expansion and the challenges associated with their design. It presents the site geologic and seismic setting, the design criteria including foundation fault rupture displacements and ship impact conditions, and the design rationale and key characteristics of Dam 1E, the largest of the Borinquen Dams.
22 Principal Engineer and Vice President, URS Corporation, Oakland, CA, [email protected] 23 Senior Geotechnical Engineer, URS Corporation, Oakland, CA, [email protected] 24 Vice President, URS Corporation, Oakland, CA, [email protected] 25 Senior Earthquake Engineer, Geotechnical Section, Autoridad del Canal de Panama, Panama, [email protected] 26 Manager, Geotechnical Section, Autoridad del Canal de Panama, Panama, [email protected]
15 NOTES
16 MYPONGA DAM STABILITY EVALUATION: MODELING STRESS RELAXATION FOR ARCH DAMS USING LINEAR FINITE ELEMENT ANALYSIS
Scott L. Jones, P.E.27 Guy S. Lund, P.E.28 Bill Moler, P.E.29 Derek Moore, P.E.30
ABSTRACT
Myponga Dam, a concrete arch dam owned and operated by the South Australia Water Corporation (SA Water), is located on the Myponga River, approximately 55 km (34 miles) south of Adelaide, South Australia. As part of a previous safety inspection, a cursory pseudo-static study of the extreme (seismic) loading condition performed in 2003 indicated the potential for overstressing of the concrete and a more detailed dynamic analysis of the dam was recommended. To address these recommendations, SA Water contracted with URS to perform a linear finite element analysis as part of a Stage 1 Safety Review of Myponga Dam. The linear finite element analysis was used to perform a stability evaluation of Myponga Dam for the usual (full supply level), unusual (inflow design flood), and extreme (maximum design earthquake) loading conditions. The initial results from the preliminary evaluation indicated the potential for overstressing, especially in the colder winter months. Based on the initial results and the understanding that the joints in the foundation would not carry significant tension, adjustments were made to the material properties in the linear model to better simulate conditions and understand the response of the dam. The updated results from the modified model indicated that the stresses in the dam were less than the allowable strength of the concrete; therefore, no further analysis was deemed necessary, allowing SA Water to move forward with the Stage 2 Safety Review without further expense on seismicity or stability evaluations.
27 Civil/Structural Engineer, URS, 8181 E. Tufts Ave., Denver, CO 80237; [email protected] 28 Principal Civil/Structural Engineer, URS, 8181 E. Tufts Ave., Denver, CO 80237; [email protected] 29 Principal Engineering Geologist, URS Australia Pty Ltd, Level 4, 70 Light Square, Adelaide, SA 5000, Australia; [email protected] 30 Principal Dams and Geotechnical Engineer, SA Water, 250 Victoria Square, Adelaide, SA 5000, Australia, [email protected]
17 NOTES
18 BLUE LAKE DAM LEFT ABUTMENT GEOLOGICAL MODELING FOR DAM RAISE
Peter C. Friz31 Dan Curtis32 James H. Rutherford33 Stephen Hart34 David C. Johnston35 Dean Orbison36
ABSTRACT
Hatch Associates Consultants Inc. was retained by the City and Borough of Sitka, Alaska to perform design engineering services for the Blue Lake Expansion Project. Due to a significant increase in load growth, the best alternative to achieve power system expansion is through increasing the dam height of the Blue Lake arch dam by 83 ft.
This paper presents a description of how a left abutment 3-D model was developed and will be used to effectively assess the complex rock blocks and jointing in order to identify kinematically viable mechanisms that need to be addressed in our analysis of the dam raise. The design for the dam raise includes an assessment of the left abutment stability, because of the potential for the formation of unstable rock blocks under loading from the raised dam that does not appear to exist on the right abutment.
During the geotechnical investigation program, geological mapping was undertaken and four boreholes were drilled on the left abutment. Using the LIDAR data and the discontinuity data collected from geological mapping and discontinuity data collected during drilling, a 3-D geological model was created.
An ANSYS analysis of the dam included the left abutment. ANSYS results will be used to estimate the forces exerted by the raised dam on each potential block identified based on the 3-D model. The stability of the blocks and the joint planes will be initially assessed using simple limit equilibrium analyses. If these analyses indicate that movement of these blocks is viable, then dynamic analyses will be considered.
31 Senior Engineering Geologist, Hatch Ltd., Vancouver, BC, Canada, [email protected] 32 Structural Analysis Group Leader for Hatch Ltd. , Niagara Falls, Ontario, Canada, [email protected] 33 Senior Structural Engineer, Hatch Associates Consultants Inc., Seattle WA, [email protected] 34 Project Manager, Hatch Associates Consultants, Inc., Seattle, WA, [email protected] 35 Senior CAD Specialist, Hatch Associates Consultants, Inc, Seattle, WA, [email protected] 36 Engineer for the City and Borough of Sitka, AK, [email protected]
19 NOTES
20 STABILITY EVALUATION OF LEFTMOST POWER-UNIT MONOLITHS OF THE THREE GORGES DAM
Haibo Liang37 Christopher S. Bailey38 Trent L. Dreese39
ABSTRACT
This paper summarizes stability analyses and evaluation of the leftmost power-station monoliths of the Three Gorges Dam. Those monoliths are constructed immediately upstream of the power station atop of a high and steep foundation cut slope which dips in a downstream direction. Problematic discontinuities dipping downstream at low angles within the cut slope pose a threat to the monolith stability against deep-seated sliding. This became one of the top issues among many challenges of the project. The Department of Hydraulic Engineering at Tsinghua University in Beijing, China was retained to perform stability analyses and evaluations of the monoliths. By employing the conventional limit equilibrium method and advanced finite element analysis, significant efforts were made to conduct the analyses and evaluate the stability of the monoliths against a deep-seated sliding potential failure. Efforts also were made to study the effect of the counter force from the cut slope on the powerhouse.
37 P.E., Senior Engineer, Gannett Fleming, Inc., P.O. Box 67100, Harrisburg, PA 17106, [email protected]; former Associate Professor at the Dept. of Hydraulic Engineering, Tsinghua University, Beijing, China 38 P.E., Senior Engineer, Gannett Fleming, Inc., P.O. Box 67100, Harrisburg, PA 17106 39 P.E., Vice President, Gannett Fleming, Inc., P.O. Box 67100, Harrisburg, PA 17106
21 NOTES
22 THREE PREDOMINATE FAILURE MODES OF THIN ARCH DAMS
Chad Gillan40 Guy Lund41 James Weldon42
ABSTRACT
Strontia Springs Dam is a double-curvature thin-arch dam located on the South Platte River in Colorado, and is owned and operated by Denver Water. The project was completed in 1986. Based on current practice, the probable maximum flood and maximum design earthquake loads are greater than those used for the design of the project. Therefore, an updated structural stability evaluation was recommended for the project.
URS performed a comprehensive structural stability analysis of the dam, and evaluated the safety of the structure against three potential failure modes that are typical for many concrete arch dams. The study used the three-dimensional finite element method of analysis to evaluate the behavior of the dam for the usual, unusual, extreme, and post- earthquake loading conditions. This paper presents an overview of the structural stability analysis, and how results were used to assess dam safety with regard to the potential failure modes, which consisted of concrete overstressing, abutment stability, and rock erosion.
40 P.E., Project Manager, URS Corporation, [email protected] 41 P.E., Senior Principal, URS Corporation. 42 P.E., Engineering Manager/Dam Safety, Denver Water
23 NOTES
24 THE INVESTIGATION OF A CONCRETE GRAVITY DAM IN A NARROW CANYON USING 3-D NONLINEAR ANALYSIS
Mike Knarr, P.E., S.E.43 Matthew Muto, Ph.D.44 Nicolas von Gersdorff45 John Dong, Ph.D., P.E.46 Ziyad Duron, Ph.D.47 John Yen, P.E.48
ABSTRACT
A series of numerical and field analyses were performed on a gravity dam located in a steep, narrow canyon for the purpose of evaluating performance under extreme flood and earthquake loading. The dam exhibits both stream and cross-stream behavior which is not captured in traditional 2-D stability analyses. To accommodate this behavior, a complete 3-D finite element model of the dam was built and analyzed. The model of the dam, which included the foundation and the reservoir, was validated through the use of low- level field testing. This paper discusses the significant aspects and findings of the 3-D modeling and analysis. This study is part of a larger effort to develop risk-based performance criteria and fragility analyses for dams to address potential failure modes that lead to risk-based decisions for resource allocation and remedial action.
43 Principal Structural Engineer, Dam Safety, Southern California Edison, San Dimas, CA 917773, [email protected] 44 Technical Specialist, Civil Engineering, Southern California Edison, San Dimas, CA 91773, [email protected] 45 Structural Engineer, Dam Safety, Southern California Edison, San Dimas, CA 91773, [email protected] 46 Structural Engineer, Dam Safety, Southern California Edison, San Dimas, CA 91773, [email protected] 47 Professor, Department of Engineering, Harvey Mudd College, Claremont, CA 91711, [email protected] 48 Chief Engineer, Dam Safety, Southern California Edison, San Dimas, CA 91773, [email protected]
25 NOTES
26 FOLSOM DAM JFP — A TALE OF STRENGTH DESIGN, RISK ANALYSIS, AND INTERAGENCY COOPERATION
Cecily M. Nolan, P.E.49
ABSTRACT
The Folsom Dam Joint Federal Project (JFP) is an auxiliary spillway being added at Folsom Lake, which was created in 1956, through the construction of a concrete gravity dam which includes the service spillway, embankment wing dams that flank the concrete dam, an embankment auxiliary dam and eight embankment dikes. The spillway includes the following: a 900-ft approach channel, a 146-ft high gated control structure, a 2095-ft long downstream chute, a 632-ft long stepped chute, and a 300-ft long stilling basin. Only the control structure design has been completed and was recently awarded to Granite Construction Company. The focus of this paper is the design process of the control structure and its appurtenances. This includes the structural design of the five concrete monoliths (both mass concrete and heavily reinforced concrete), six bulkhead gates, and six submerged tainter gates (including their anchorage). Note that geotechnical design sometimes overlapped with the structural analysis, especially as the control structure foundation affected the propagation of seismic accelerations. The design was performed concurrently by both the U.S. Army Corps of Engineers (Corps) and the U.S. Bureau of Reclamation (Reclamation). Each agency has its own design methodologies and criteria. In this unique project, satisfying both has been an additional challenge and has afforded the opportunity to compare and contrast the criteria. This paper describes the background of the project and the methodologies and criteria of each agency. In addition, discussion is presented on how the two sets overlap, how the agencies have cooperated, and how the final designs have been affected by each agency’s philosophy.
49Structural Engineer, U.S. Army Corps of Engineers, American River Design Section, 1325 J Street, Sacramento, CA 95814, [email protected]
27 NOTES
28 SELECTING STRENGTH INPUT PARAMETERS FOR STRUCTURAL ANALYSIS OF AGING CONCRETE DAMS
Timothy P. Dolen50
ABSTRACT
The Bureau of Reclamation Dam Safety Program performs periodic examinations and risk analysis of all of their dams. Structural analysis results are typically used during a risk analysis to estimate the failure probabilities of concrete dams under static, hydrologic, and seismic loadings. The probability of failure is estimated, often considering average, high, and low strength properties of mass concrete. Not all dams have a complete history of construction and the strength properties must be assumed. A database of mass concrete core tests from the past 50 years was analyzed to determine bond strength input parameters. The average direct tension and shear properties of lift lines were compared for different state-of-the-practice construction methods in the 20th Century. The properties were estimated for three primary construction eras and separately for dams suffering from alkali-aggregate reaction. In addition to bond strength, the percent of bonded lift lines greatly influenced the input parameters for these construction eras.
50 Bureau of Reclamation, P.O. Box 25007, 86-68180, Denver, Colorado, 80225, 303-445-2380, Fax: 303- 445-6341, [email protected].
29 NOTES
30 WYARALONG RCC DAM SUMMARY & THE IMPACT OF “LOW” QUALITY AGGREGATE ON DESIGN
Colleen Stratford51 Emily Schwartz52 Robert Montalvo53 Ernest Schrader54 Richard Herweynen55
ABSTRACT
Wyaralong dam in Southeast Queensland, Australia is a 47 m high RCC dam containing 160,000 m3 of RCC. Influenced by foundation concerns, the design used a reasonably wide base. In combination with low seismic loading, this resulted in low stresses on the order of only 1 MPa compression with no significant tension. The design team opted to achieve water tightness by using a “wetter” consistency RCC having a cement plus fly ash content of 85 + 85 kg/m3, which is much more than needed for strength. This normally would have required considerable cost to control thermal stresses due to seasonal temperature changes, heat from hydration, and stiffness of the RCC. Typically, the modulus for a mix like this would be about 27 GPa. Tests with imported basalt, initially considered by “traditional thinking” to be necessary because of the poor quality of on-site sandstone, had these values. However, because strength was not an issue, sandstone was also included in studies of potential aggregate. The low specific gravity of 2,460 to 2,510 kg/m3 and high absorption of 4.8% to 5.2% normally indicate unsuitable material. However, adequate strengths were achieved, and tests showed durability would not be an issue. In addition to cost savings and avoiding issues related to hauling aggregate from a remote source, the most valuable advantage of the on-site sandstone was its low RCC modulus at 10 GPa. In combination with high creep, thermal stresses were reduced enough to allow placing with no forced cooling.
51 Designer, SMEC, Level 5, 71 Queens Road, Melbourne, Victoria 3004, Australia, Australia, [email protected] 52 Thermal & Field Engineer, Paul C. Rizzo Associates, Suite 100, Building 5, 500 Penn Center Blvd., Pittsburgh, PA, 15235, USA, [email protected] 53 Quality & RCC/Materials Manager, Macmahon, Level 3, 104 Melbourne St, South Brisbane 4101, Queensland, Australia, [email protected] 54 Consultant, Schrader Consulting, 1474 Blue Creek Road, Walla Walla, WA 99362, USA, [email protected] 55 Lead Dam Designer, Entura, GPO Box 355, Hobart 7001, Tasmania, Australia, [email protected]
31 NOTES
32 LIMESTONE FILLER USED AS CEMENTITIOUS MATERIAL IN THE MIX FOR THE LARGEST RCC DAM IN EUROPE: LA BREÑA II
Rafael Ibáñez de Aldecoa56 Gonzalo Noriega57 Antonio Sandoval58 Miguel Sanz59
ABSTRACT
La Breña II is a roller-compacted concrete (RCC) straight gravity dam located on the Guadiato River, about 25 km southwest to the city of Cordoba in Southern Spain. With a height of 119 m, and RCC volume of 1.4x106 m3 -out of a total of 1.6x 106 m3 of concrete placed-, La Breña II is the largest RCC dam built in Europe. The use of a high (230 kg/m3) cementitious content RCC mix, of which 70% was to be flyash, required a total flyash consumption of roughly 225,000 t during a planned 20 month construction period. This would have required an average flyash supply of approximately 11,000 t/month, with peaks on the order of 21,000 t/month and 1,100 t/day. In depth market investigation showed that, even monopolizing the flyash supply available from several Spanish and Italian thermal power plants, it was very uncertain to fulfill the target. Therefore an alternative using a second type of mineral admixture that would reduce the need for flyash was carefully studied.
The chosen option was to use a limestone filler that complies with the European Standard EN 197-1 as a suitable mineral admixture with required cementitious properties, which could be used by cement manufacturers to produce certain types of common cements. The use of this limestone dust in the RCC mix for La Breña II, in a proportion of 20% by weight with respect to the total cementitious materials, resulted in satisfactory long term concrete strengths that met the project requirements and exceeded all expectations.
La Breña II RCC dam is owned by AcuaSur, the designer for the Construction Design was Idom, the site engineer Initec Infraestructuras, and the contractor Dragados S.A.
56 Head Hydraulic Works Division, Dragados S.A., Avda. Camino de Santiago, 50, 28050 Madrid, Spain, [email protected] [Member of SPANCOLD] 57 Portugues RCC Dam Construction Manager, Dragados-USA, Road PR10, km 5.5, Ponce, PR 00731, [email protected] [La Breña II RCC Dam Construction Manager] 58 Water Supply and Irrigation Technical Manager, acuaSur, Pza. Cuba, 9, 41011 Seville, Spain, [email protected] [La Breña II RCC Dam Project Manager] 59 Hydraulic Works Division, Dragados S.A., Avda. Camino de Santiago, 50, 28050 Madrid, Spain, [email protected]
33 NOTES
34 BEYOND RCC — BUILDING QUALITY INTO THE SAN VICENTE DAM RAISE
James L. Stiady, Ph.D., P.E./G.E.60 Russell Grant, P.E.61 David Ribble62 Wade Griffis, P.E.63
ABSTRACT
The San Vicente Dam Raise (SVDR) will be the tallest dam raise in the United States and tallest roller compacted concrete dam (RCC) raise in the world. Building quality into the San Vicente Dam Raise project began at the inception of the project by focusing two key elements: selecting highly qualified teams and enhancing the quality assurance program.
First, the Design Team and Construction Management (CM) Team were selected based on the qualification and experience of the individuals that will be involved directly in the project. Because this is a specialized and complex construction project, the construction prime contractors were prequalified to ensure the firms bidding on the project possessed the required experience and financial stability to complete the work on schedule and budget, and to a high quality standard. The prequalified primes then participated in a competitive bidding process.
Second, the Quality Assurance (QA) program was developed with two goals: assuring that the final product meets the design requirements and requiring the contractor to focus on process control. With the understanding that quality is built in the field, the contractor Quality Control (QC) program is closely monitored by the QA team, and inspection is focused on the contractor’s process instead of just the final product. The QA testing program is enhanced by constructing a state of the art, American Association of State Highway Transportation Officials (AASHTO) accredited, onsite materials testing laboratory.
60 Senior Engineer, G2D Resources, LLC, 7966 Arjons Drive, Suite 204, San Diego, California 92126. [email protected]. 61 Project Manager, Kleinfelder, 611 Corporate Circle, Suite C, Golden, Colorado 80401. [email protected]. 62 Quality Assurance Manager, Parsons/Black & Veatch Joint Venture, 12393 Moreno Avenue, Lakeside, California 92040. [email protected]. 63 Lead Construction Administrator, San Diego County Water Authority, 4677 Overland Avenue, San Diego, California 92123. [email protected].
35 NOTES
36 DIRECTIONAL DRILLING FOR HIGH CAPACITY ANCHORS AT BLUESTONE DAM
Mark J. Rothbauer, P.E.64 Jeff R. Hopple, E.I.T.65
ABSTRACT
Bluestone Dam is located in Hinton, West Virginia and is owned and operated by the United States Army Corps of Engineers. Ongoing phased construction to correct deficiencies identified in the Dam Safety Assurance Program includes the installation of rock anchors containing up to 61 strands in 15-inch diameter holes. Due to embedded structures in the dam and close anchor spacing, conventional drilling tolerances would increase the risk of intercepting structures or intersecting adjacent drill holes or tensioned anchors. Directional drilling pilot holes is used to meet the specified tolerances, preventing interception and intersection issues. A real time, optical directional drilling system is used to drill the holes. This system was selected to maximize the drilling capability and limit site conditions from affecting the directional drilling. This system has a number of unique components compared to conventional anchor hole drilling. After the pilot hole is completed, the hole is reamed to the final diameter. Each hole is surveyed to ensure it meets the tolerance requirements. The system is able to drill straight holes meeting a tolerance of 1:150 on holes as deep as 270-feet. Significant lessons learned from the project are discussed including a summary of the capabilities and limitations of the directional drilling system used on the project.
64 Project Executive, Brayman Construction Corporation, 1000 John Roebling Way, Saxonburg, PA 16056 [email protected] 65 Project Engineer, Brayman Construction Corporation, 1000 John Roebling Way, Saxonburg, PA 16056 [email protected]
37 NOTES
38 ESTIMATED SHEAR STRENGTH OF SHEAR KEYS AND BONDED JOINTS IN CONCRETE DAMS
Dan D. Curtis66
ABSTRACT
The shear strength of bonded lift joints and shear keys is important to overall dam stability during an earthquake but it is poorly understood. This paper provides a brief review of shear strength data from recent testing and available literature to estimate the strength of shear keys in vertical contraction joints and bonded horizontal lift joints in concrete dams.
Three shear failure criteria for concrete are compared to assess the shear strength of shear keys and lift joints. The Griffith failure criteria is selected as the most appropriate because it tends to provide a lower bound estimate of strength and it is appropriate for brittle materials like concrete subjected to shear loading. Relatively simple shear strength equations are developed and compared to results available from the literature. Both static and dynamic shear strengths are given. The resulting shear strength parameters are compared to shear strengths which have traditionally been used in dam design and assessment. It is concluded that relatively high shear strengths are available particularly under dynamic conditions.
66 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]
39 NOTES
40 NEW MATERIALS AND TECHNOLOGIES FOR LEAKAGE SEALING WITHOUT AFFECTING OPERATION — HIGH PRESSURE RESIN INJECTIONS
A. Gonzalo67 J. Alonso68 F. Vazquez69 A. Vaquero70
ABSTRACT
Dam repair works often require the reservoir to be emptied, which can be a problem. New materials and technologies developed in Spain in the last decade avoid this problem, allowing large leaks to be sealed and structural monolithism to be recovered, even under high water pressure, without polluting the environment. The use of high viscosity, thixotropic polymers, almost visco-elastic solids, in addition to the design of new and powerful pumps able to inject these polymers up to 60 MPa, have enabled more than 100 dams to be repaired without disturbing their operation.
67 Dr, Civil Engineer. HCC General Manager . Madrid, Spain. alberto@hcc-es,com 68 Civil Engineer. ENDESA. Manager of Civil Works and Enviromment. Ponferrada. Spain. [email protected] 69 Civil Engineer. EMASESA. Operations Dams Manager. 70 Civil Engineer. HCC. Project Manager. Madrid. Spain. [email protected]
41 NOTES
42 PENSTOCK SCOUR FORMATION AT BLUESTONE DAM
71 E.F.R. Bollaert
ABSTRACT
This paper presents some results of a 3D scour assessment downstream of the penstocks of Bluestone Dam, West Virginia, US. The assessment makes use of the Comprehensive Scour Model (CSM) developed by Bollaert (2002, 2004). This practical engineering model is physics based and relates the hydrodynamic pressure fluctuations generated by flow spillage to the resistance of the downstream foundation to rock block ejection, rock mass fracturing and rock block peeling off. It has been developed based on detailed pressure measurements performed on a near-prototype scaled experimental facility and accounts for two-phase transient wave propagation of pressures inside joints of the rock. The model is not only able to predict the ultimate scour depth, but also the time and spatial evolution of the scour hole as a function of future flood events.
At Bluestone Dam, the jets issuing from the penstocks are very shallow and, as such, generate particular 3D flow turbulence conditions inside the flow dissipation area just downstream. The CSM has been adapted and applied to these shallow turbulent jets in order to allow a 3D spatial assessment of the time evolution of scour formation through the rocky foundation. This foundation mainly consists of ortho-quartzite, interbedded shale layers and claystone. These complex local geological conditions have been accounted for with depth in a quasi-3D manner. The model predicts future scour development by rock mass fracturing (CFM), rock block uplift (DI) and finally rock block peeling off by return currents (QSI, Bollaert 2009). The latter is of particular importance because it directly leads to regressive erosion towards the toe of the dam.
71President, AquaVision Engineering Ltd., Chemin des Champs-Courbes 1, CH-1024 Ecublens, SWITZERLAND, [email protected]
43 NOTES
44 DESIGNING THE FOLSOM AUXILIARY SPILLWAY PIERS USING LS-DYNA® TIME-HISTORY RESULTS
Eric Kennedy, P.E.72
ABSTRACT
The Folsom Auxiliary Spillway is a joint project between the U.S. Army Corps of Engineers and the Bureau of Reclamation for flood damage reduction and dam safety purposes. The spillway will increase the discharge capacity from the Folsom Reservoir, enabling it to pass the probable maximum flood (PMF). The main feature is the concrete control structure, which consists of three non-flow-through monoliths and two flow- through monoliths, each of which contains three bulkhead and three tainter gates. An LS- DYNA model of the control structure was developed for evaluation, design, and verification of several components. Two water surfaces were modeled, one representing the PMF and the other the maximum normal pool; the latter was combined with two operational scenarios and 28 combinations of ground motions to envelope the expected demand on the structure.
This paper focuses on utilizing results from the LS-DYNA model to design the spillway piers. Because of site constraints and hydraulic requirements, the piers have a higher aspect ratio than would be expected, the obvious result of which is an increase in steel reinforcement. The model output included nodal forces at several locations in each pier; these were translated into axial, moment, and shear demands on tributary strips of the piers. The axial force on each strip was used to calculate both moment and shear capacities. At each output time step, instantaneous demand-to-capacity ratios were evaluated using Corps criteria for the allowable magnitude and number of exceedences. The resulting design concentrates the heaviest reinforcing only where necessary, resulting in a substantial cost savings.
72 Civil Engineer, U.S. Army Corps of Engineers, Structural Design Section, 1325 J Street, Sacramento, CA 95814, [email protected]
45 NOTES
46 LARGE-EDDY SIMULATION OF FLOW OVER A LOW-HEAD DAM
Piroz Zamankhan73
ABSTRACT
Flow over a low-head dam is quite complex. A dangerous roller may develop on the down-stream of the dam which makes it difficult to dislodge floating objects. This paper presents the results of a simulation using the large-eddy simulation technique (LES) and the level-set approach to predict the flow over a low-head dam. Qualitative and quantitative comparisons with experimental results provide insights in the capabilities of LES and the level-set approach to predict complex two-phase flows including flow over a low-head dam or a sharp-crested weir. In addition, suggestions are made on how to diminish the hazards associated with rollers.
73 Faculty of Industrial, Mechanical Engineering and Computer Sciences , University of Iceland Hjardarhagi 2-6, IS- 107 Reykjavik, Iceland, [email protected]
47 NOTES
48 SENSITIVITIES OF CHANNEL GEOMETRY COMPARED TO MODELING ASSUMPTIONS IN DAM FAILURE ANALYSIS
Joey M. Windham, P.E74
ABSTRACT
This research includes a sensitivity analysis of channel geometry and model assumptions in 1 dimensional (1D) dam break analysis. The specific modeling assumptions that are analyzed include: breach development time, breach width, and breach side-slopes. The question always arises when doing 1D dam break modeling of how detailed does the geometry data need to be to answer the subject question within an acceptable tolerance. LIDAR data and bathymetric data used for channel characteristic add significant detail to the model geometry as opposed to using coarse gridded data such as the USGS 10 meter Digital Elevation Models (DEMs). However, as geometry detail increases so does model development time, model run time, and cost to retrieve data. This research analyzes the level of error introduced in model results from accuracy of channel geometry as compared to the level of error introduced from assumptions made in breach characteristics.
74 Civil Engineer, United States Army Corps of Engineers, Vicksburg District, 4155 East Clay Street, Vicksburg, MS 39183, [email protected]
49 NOTES
50 DAM FAILURE SYSTEM MODELING IN THE MUSKINGUM WATERSHED — BEACH CITY DAM
Edward L. Stowasser, P.E.75
ABSTRACT
Beach City Dam is one of sixteen flood control projects located in the Muskingum Watershed. The Huntington District, U.S. Army Corps of Engineers was tasked to model a dam failure for Beach City Dam and provide water surface profiles and inundation mapping to aid in estimating consequences. The district developed a system model to incorporate the water management of the entire basin during a probable maximum flood and the residual rainfall affects on the surrounding sub-basins in the watershed. The entire system includes modeling of over 200 miles of stream. The model has also been used to develop dam failure models for Dover Dam, Bolivar Dam, and Mohawk Dam located within the same basin.
A new PMF was developed for the Beach City modeling efforts using HMR 51 and 52. A HEC-HMS model was used for rainfall-runoff estimation by applying initial and constant loss rates and determining the runoff hydrographs. The runoff hydrographs were generated by obtaining antecedent floods as input into the development of a HEC-ResSim model. This model was created to determine how all sixteen dams would operate for downstream impact areas. Finally, HEC-RAS was used to calculate the water surface profiles and inundation areas to aid in consequence estimation. This paper will provide an overview of the methods used in developing all the system model programs and components for the Beach City Dam Failure Study.
75 Hydraulic Engineer, U.S. Army Corps of Engineers, Huntington, WV 25701, [email protected]
51 NOTES
52 UNSTEADY FLOW SIMULATIONS AND INUNDATION MAPPING FOR THE MISSOURI RIVER MAIN-STEM DAM SYSTEM
Thomas Gorman76 Curtis Miller77 Lowell Blankers78 Laurel Hamilton79 Neil Vohl80 Megan Splattstoesser81
ABSTRACT
The U.S. Army Corps of Engineers, Northwest Division, operates six dams and reservoirs on the main-stem of the upper Missouri River. The total system gross storage is about 73.4 million acre feet. For purposes of evaluating multiple dam safety related scenarios which included dam failures, hydraulic analyses were developed for the system. These analyses were conducted by the Corps’ Modeling, Mapping and Consequences (MMC) Production Center for the Critical Infrastructure Protection and Resilience (CIPR) program.
Unsteady flow hydraulic analyses were accomplished using the HEC-RAS computer program. It was desired to model the entire reach of the Missouri River from each dam to the river mouth. From the most upstream dam, Fort Peck Dam in Montana, to the confluence with the Mississippi River near St. Louis is a stream distance of approximately 1770 miles.
Geometric data from previously developed HEC-RAS and HEC-2 hydraulic models was combined and extended with geometric data extracted from 10-meter digital elevation models (10m DEM) using the HEC-GeoRAS program. The hydraulic models included dam outlet works operations, storage areas, downstream levee systems and tributary inflows.
An important part of the analyses was the use of HEC-GeoRAS as an automated method to rapidly develop inundation mapping for the different scenarios. The results of the study are being compiled by the MMC into map atlas end products, or Emergency Action Plans (EAP) maps, providing inundation maps for selected scenarios displaying flood arrival times for the flood peaking at various downstream locations.
76 Hydraulic Engineer, U.S. Army Corps of Engineers, Omaha District, Omaha, NE, 68102, [email protected] 77 Hydraulic Engineer, U.S. Army Corps of Engineers, Omaha District, Omaha, NE, 68102, [email protected] 78 Hydraulic Engineer, U.S. Army Corps of Engineers, Omaha District, Omaha, NE 68102, [email protected] 79 Hydraulic Engineer, U.S. Army Corps of Engineers, Omaha District, Omaha, NE, 68102, [email protected] 80 Hydraulic Engineer, U.S. Army Corps of Engineers, Omaha District, Omaha, NE, 68102, [email protected] 81 GIS Specialist, U.S. Army Corps of Engineers, Omaha District, Omaha, NE, 68102, [email protected]
53 NOTES
54 MODELING DAM FAILURES OF THE RANCOCAS CREEK WATERSHED IN SOUTHERN NEW JERSEY
Arthur C. Miller82 Dennis Johnson83 Norman Folmar84
ABSTRACT
In the evening of July 12, 2004, an intense rainfall fell on much of the Rancocas Creek watershed in Southern New Jersey. Due to the large amount of rainfall and the inadequate size of many of the dam outlet structures, 16 dams located within the 347 square mile watershed overtopped and failed. The purpose of the study was to determine what, if any, increased flooding occurred due to the failure of the dams.
Several U.S. Army Corps of Engineers (USACE) computer software programs were used in this study. The HEC-HMS computer model was used for the hydrologic modeling and Geo-HMS was used to develop the basin model, which consisted of 86 sub-basins. Radar derived precipitation hyetographs were obtained for the event, and hyetographs were developed for each sub-basin at a six minute time resolution. The model was calibrated using recorded hydrographs from four USGS stream gages within the watershed.
An unsteady flow model was then developed using the HEC-RAS computer program. Cross-sectional geometry data were developed using Geo-RAS with the LIDAR data. The geometry model consisted of 13 river reaches. Stream flow hydrographs determined from HEC-HMS were inputted into the HEC-RAS model for all 86 sub-basins. The dams were modeled as inline weirs. A total of 33 dams were modeled with 16 of them breaching. Comparisons of results were made between peak stages obtained from model executions for the dam breach conditions and those with the dams not being breached.
82Distinguished Professor Emeritus, Department of Civil and Environmental Engineering, Penn State University, AECOM Science Practice Leader, State College, PA 16801, [email protected] 2Professor, Juniata College, Huntingdon, PA 16652, [email protected] 84Assistant Professor of Civil and Environmental Engineering, Penn State University, AECOM Engineer III, State College, PA 16801, [email protected]
55 NOTES
56 DEVELOPMENT OF COMPUTATIONAL METHODOLOGY TO ASSESS EROSION DAMAGE IN DAM SPILLWAYS
B. Dasgupta85 D. Basu86 K. Das87 R. Green88
ABSTRACT
High-velocity overflow from free jet spillways or overtopping of dams during flooding can cause significant erosion of the riverbed rock mass and risk instability of the dam foundations. Erosion is caused when the erosive capacity of the water exceeds the resistive capacity of the rock mass. In this paper, a methodology is presented to model the complex-flow-induced damage mechanism of the erosion, numerically accounting for both the fluid flow and its effect on the geomechanical behavior of the rock. The erosive capacity of water is estimated by computational fluid dynamics (CFD) simulation of the free jet flow and turbulence in the plunge pool. The resistive capacity of the rock is addressed by discontinuum modeling of the jointed rock under the hydrodynamic forces obtained from the flow analysis. Erosion of the rock in the plunge pool of the Kariba Dam, located in Zimbabwe, is used as an example to demonstrate the capability of the methodology. This explicit modeling approach provides support to the traditional physics-based approaches such as the Erodibility Index Method (EIM) and the Comprehensive Scour Model (CSM) used in industry. The compulational approach provides flexibility over the existing approachs because it allows multiple full-scale flow simulations and geomechanical analyses to understand the effects of ranges of parameters on the erosion mechanism and aid in mitigation design (e.g., rock bolts and rock anchors).
85Staff Engineer, Geosciences and Engineering Division, Southwest Research Institute®, San Antonio, TX 78238, ([email protected]) 86Research Engineer, Geosciences and Engineering Division, Southwest Research Institute®, San Antonio, TX 78238, ([email protected]) 87Research Engineer, Geosciences and Engineering Division, Southwest Research Institute®, San Antonio, TX 78238, ([email protected]) 88Institute Scientist, Geosciences and Engineering Division, Southwest Research Institute®, San Antonio, TX 78238, ([email protected])
57 NOTES
58 ECONOMIC ANALYSIS OF PRIVATIZED HYDROELECTRIC POWER PLANT PROJECTS IN TURKEY
Murat Gunduz89 Haci Bayram Sahin90
ABSTRACT
Since Turkey has increasing energy consumption, electricity generating projects are recently very popular. In 2010 spring, privatization of energy projects including 52 hydroelectric power plant projects (HEPP), which are under operation, took place in Turkey. 617 companies responded to the bid and competition was very big. In this study, economic analyses of 19 group projects, which total 52-HEPP projects, were performed. 34 of those projects were investigated at the site and information of all projects was gathered. An economic analysis table is created for each group of projects. Based on the analyses, economic results of bid prices for each group were determined and compared with each other.
89 PhD, Associate Professor, Department of Civil Engineering, Middle East Technical University, Ankara, Turkey, [email protected] 2Civil Engineer, GESTAS Construction Inc Co., Ankara, Turkey, [email protected].
59 NOTES
60 POST-TENSIONED TRUNNION ANCHOR ROD TESTING, WEST POINT DAM AND R.F. HENRY DAM
George V. Poiroux, P.E.91
ABSTRACT
The Corps of Engineers (COE) embarked on a nationwide mission to construct navigation and hydroelectric projects during the 1960s and 1970s. During this time period, the use of post-tensioned trunnion anchor rods for support of tainter gates became the standard for the COE and was also embraced by other governmental agencies and industries within the United States and abroad. Retaining tension in this anchorage system is critical in providing an acceptable Factor-of-Safety for the tainter gates being structurally supported.
Currently, the only means to measure the tension in these post-tensioned anchor rods is a lift-off test. Lift-off testing is logistically challenging, dangerous, and could potentially be destructive. This paper will present the results of a newly developed non-destructive technology using a dispersive bending wave at various frequencies to estimate the tension in individual anchor rods. The paper will also include our attempt to validate the tension estimated by this new technology with actual lift-off test results from two Corps of Engineers Dams, West Point Dam in West Point, Georgia and R.F. Henry Dam near Selma, Alabama.
91Chief Geotechnical, Environmental & HTRW Branch , US Army Corps of Engineers, Mobile District Office, 109 St. Joseph, Mobile, AL 36602, [email protected]
61 NOTES
62 INTELLIGENT FLOW CONTROL AFTER LOAD REJECTION AT THE JUNIPER RIDGE HYDROELECTRIC POWER GENERATION PROJECT BEND, OREGON
Alden C. Robinson, PE92 Z. (Joe) Zhao, PE, Ph.D.93
ABSTRACT
A new hydroelectric project with a long and large diameter steel penstock was designed and constructed with a bypass system for the Central Oregon Irrigation District (COID). During normal operation, flow passes through the turbine to generate electricity. However, for abnormal conditions or maintenance, flow will be switched to the bypass system. There are two major requirements for the hydraulic system. First, the flow rate downstream of the hydroelectric facility must remain constant always. Second, transient pressures in the hydraulic system after load rejection must be properly controlled. To meet these requirements, intelligent flow controls are required. In order to design and implement a proper flow control scheme, numerical modeling of the entire hydraulic system was performed. The numerical modeling helped evaluate various flow conditions in the system with three goals: 1) control the discharge downstream of the powerhouse by adjusting turbine wicket gates and valves; 2) compute the highest hydraulic pressures including positive transient pressures along the entire hydraulic system such that they are lower than the allowable design values of the penstock and the associated components; and 3) compute the lowest hydraulic pressures including negative transient pressures along the entire hydraulic system such that vacuum conditions are not induced. These challenges were successfully resolved by COID at the Juniper Ridge Hydroelectric Power Generation Project in 2009-2010 and are described herein.
92 President/CEO, Sunrise Engineering Inc., 25 East 500 North, Fillmore, Utah 84631, arobinson@sunrise- eng.com 93 Project Engineer/Manager, Sunrise Engineering Inc., 12227 South Business Park Dr., Draper, Utah 84020, [email protected]
63 NOTES
64 SAFE GROUTING PRESSURES FOR DAM REMEDIATION
Jeffrey A. Schaefer, PhD, PE, PG 94 David B. Paul, PE95 Douglas D. Boyer, PE, CEG96
ABSTRACT
Signs of embankment displacement and hydrofracture have been observed on several recent U.S. Army Corps of Engineers (USACE) dam grouting projects and at dam projects for various other agencies and dam owners over the years. The grouting procedures employed at the USACE projects were all following established “rules of thumb” for safe grouting pressures. Although the “rules of thumb” are good starting points, they were generally developed for new dam construction, and this paper demonstrates why the rules of thumb are not appropriate for grouting through existing dam embankments. A more rigorous method for determining safe grouting pressures is proposed. It is based on estimating the minor effective principle stress in the dam and foundation using basic finite element modeling. It is recommended that when grouting through existing dams, the effective grout pressure should stay below the effective minor principle stress for all stages that could have connections to embankment materials or foundation soils. Although it may be likely that the pressures required to perform a foundation grouting project may be much higher than the limiting safe grouting pressures, these decisions should be made consciously with respect to the overall safety and stability of the dam.
94Lead Civil Engineer, U.S. Army Corps of Engineers, Risk Management Center, Institute for Water Resources, 600 Dr. Martin Luther King Jr. Place, Louisville, KY 40202, [email protected], Phone 502-315-6452 95Lead Civil Engineer, U. S. Army Corps of Engineers, Risk Management Center, Institute for Water Resources, 12300 W. Dakota Ave Suite 230, Lakewood, CO 80228, [email protected], Phone 720-289-9042 96Western Division Chief, U. S. Army Corps of Engineers, Risk Management Center, Institute for Water Resources, 12300 W. Dakota Ave Suite 230, Lakewood, CO 80228, [email protected], Phone (303) 349-4061
65 NOTES
66 ROCK GROUTING FOR DAMS AND THE NEED TO FIGHT REGRESSIVE THINKING
Dr. Donald A. Bruce, C.Eng.97
ABSTRACT
It is generally recognized, both nationally and internationally, that rock grouting theory and practice in North America has undergone a most positive revolution during the last decade or so. Key elements of this progress have included the development and use of suites of balanced, stable High Mobility Grouts (HMG); increasing use of Low Mobility Grouts (LMG); new overburden and rock drilling methods; computer monitoring control and analysis; and the use of Apparent Lugeon Theory and Lugeon testing to assure proper stage refusals and low residual permeabilities, respectively. These concepts have been most strongly implemented on major Federal dam remediation projects. Also, certain consultants are using them on smaller, non-Federal projects.
However, the author has noted over the past few years a distinctly retrogressive faction in the grouting industry which, if left unchallenged, will undo much of the advantages gained over the last decade. Examples include a reversion to the use of highly unstable HMG’s as engineers confuse “thin” and high water content. Perhaps more concerning is the re-emergence in certain circles of the thirty-year-old GIN Method (Grouting Intensity Number). This method was devised with the laudable goal of trying to assure a certain basic standard of care in grouting projects in countries of a lesser degree of resource and sophistication.
In this paper, the author urges against the regression in U.S. grouting practice, which is in danger of occurring due to a relapse into old, unsatisfactory habits, and a “rediscovery” of outdated and inappropriate methodologies. The U.S. grouting industry today is ranked amongst the most active and effective in the world, and this level of approbation should be guarded and cultivated, not let slide.
97President, Geosystems, L.P., P.O. Box 237, Venetia, PA 15367, U.S.A.; Phone: (724) 942-0570; Fax: (724) 942-1911; Email: [email protected].
67 NOTES
68 EVALUATING THE RISKS OF AN INTERNAL EROSION FAILURE AT AMISTAD DAM
William O. Engemoen98 Randel Mead99 Luis Hernández100
ABSTRACT
Amistad Dam is an important storage and flood control facility on the Rio Grande operated by the United States and Mexico Sections of the International Boundary and Water Commission. This large dam, which contains a concrete section and two very long embankment sections, was constructed on a karstic foundation of soluble limestone and marl. Since construction, extensive seepage has been measured downstream and sinkholes have been discovered and treated in the reservoir area. Although the embankment sections have performed satisfactorily in the 41-year operational history of the dam; the karstic foundation conditions, high seepage flows, and sinkhole formation pose a real concern for the potential of ongoing or future internal erosion of the embankment and foundation. A joint team of engineers from both Mexico and the United States was convened to discuss the various methods in which the dam may fail and to estimate the risks of such a failure. This process included a review and evaluation of the design, construction, and past performance of the facility; the development of potential failure modes; an estimation of the probability of dam failure under each failure mode; and the evaluation of potential consequences in Mexico and the United States in the event of a dam failure. This process has resulted in a better understanding of the threat posed by internal erosion at this dam with a karstic foundation, and has led to a plan for the future investigations and actions necessary to better evaluate and protect the structure against various types of internal erosion failure modes.
98Geotechnical Engineer - Bureau of Reclamation, Denver, Colorado, [email protected] 99Geotechnical Engineer – US Army Corps of Engineers, Tulsa, Oklahoma, [email protected] 100Civil Engineer – International Boundary and Water Commission – US Section, El Paso, Texas, [email protected]
69 NOTES
70 GEOLOGIC DATA AND RISK ASSESSMENT; IMPROVING GEOLOGIC THINKING AND PRODUCTS
Peter T. Shaffner101
ABSTRACT
One of the most important dam safety tools available for summarizing, focusing, and understanding dam foundation performance and potential failure modes is a robust set of foundation drawings combining geologic and geotechnical data with instrumentation response information. Understanding potential failure modes and using the risk evaluation process can provide focus to the creation and development of these important subsurface drawings, and improve the efficiency of foundation exploration. An impressive amount of important information can be synthesized, portrayed and summarized in detailed subsurface drawings, and this process must not become a lost art due to advancements in computer modeling capabilities. This paper will discuss the need for geologists and engineers to work together to define and develop foundation drawings and summary documents critical for dam safety evaluations, including failure mode analysis and risk assessment. The advantages that engineering geology drawings and focused summary documents provide for improving the review process are described. Several example plan maps and cross sections are provided, however these are intended to be viewed as full size drawings and are not as useful in a reduced format.
Many quotes from Dr. Ralph Peck are included throughout this paper. Most of these quotes were taken from DiBiagio, Elmo and Flaate, Kaare (2000). Dr. Peck spoke frequently on the power of careful and trained observation, the necessity for sound engineering judgment, and the value of developing concise summaries of problems and solutions. He and Dr. Terzaghi always spoke of the importance of geology. All of those concepts match the philosophies presented here regarding engineering geology and the development of foundation drawings. In fact, Dr. Terzaghi considered soil mechanics a sub-discipline of geology and in 1929, Terzaghi, along with Redlich and Kampe, published their own Engineering Geology text.
101 Engineering Geologist, PG, Corps of Engineers Risk Management Center, 12300 W Dakota Ave, Suite 230, Lakewood, CO 80228, [email protected]
71 NOTES
72 ASSESSING THE POTENTIAL FOR SEEPAGE BARRIER DEFECTS TO PROPAGATE INTO SEEPAGE EROSION MECHANISMS
Ryan G. Van Leuven102 Dr. John D. Rice103
ABSTRACT
Seepage barriers have been used extensively to mitigate seepage problems in dams and levees. Although the design of many of these dams and levees has been based on intact barriers, seepage barriers have been shown to be susceptible to deformation and cracking when high differential hydraulic pressures act across the barrier. Under certain conditions, these cracks can lead to serious seepage problems which could potentially lead to the development of a low-resistance seepage pathway. Three scenarios have been identified where there is the potential for erosion to occur adjacent to a crack in a barrier: 1) erosion at the interface between a fine grained soil and a course grained soil, 2) erosion of overlying soil due to flow along a joint in bedrock, and 3) erosion of the barrier material. The objective of this study is to investigate the first mode of erosion and identify the conditions at which more serious seepage problems can develop. The research has been performed using a laboratory model to simulate conditions near a seepage barrier crack under the scenarios described above. The results from the laboratory testing were compared to finite element seepage models for each scenario to estimate the flow velocities near the crack. The flow velocities were compared to critical velocities of the soil estimated from published relationships to estimate where erosion is likely to occur. A comparison was made between the observed behavior in the model and the behavior predicted with the computer model. Although not presented in this paper, the results of the research will be used to develop a method to assess the potential for erosion to occur and develop into a failure mode based on conditions near seepage barrier cracks.
102 Graduate Student, Department of Civil & Environmental Engineering, Utah State University, Logan, UT 84322, [email protected] 103 Assistant Professor, Department of Civil & Environmental Engineering, Utah State University, Logan, UT 84322, [email protected]
73 NOTES
74 RELIABLE SEEPAGE CONTROL BY PLASTIC CONCRETE CUT-OFF WALLS
Peter E. Banzhaf104 Eckart Colmorgen105
ABSTRACT
New hydro projects, upgrading by heightening of existing embankment dams, as well as remedial works on aging dams and their foundations require reliable seepage control for durable dam safety.
The combination of cut-off wall installation using suitable, project specific designed plastic concrete together with the new cutter generation designed for challenging, extreme soil-rock formations allow the effective and successful treatment of seepage prone foundations.
Concrete cut-off walls for the upgrade or remediation of existing dams with larger depths to be reached and the execution of projects in areas with challenging soil-rock-conditions are being successfully executed.
104 Dipl.-Ing., Bauer Spezialtiefbau GmbH, BAUER-Str. 1, 86529 Schrobenhausen, Germany [email protected] 105 Dipl.-Ing., Bauer Spezialtiefbau GmbH, BAUER-Str. 1, 86529 Schrobenhausen, Germany [email protected]
75 NOTES
76 ASSESSMENT AND ANALYSIS OF WYARALONG DAM FOUNDATION
Jared Deible, P.E. 106 Richard Herweynen107 John Ager108
ABSTRACT
Wyaralong Dam is a Roller Compacted Concrete (RCC) dam located on the Teviot Brook near the township of Beaudesert in south-east Queensland, Australia. The dam is approximately 48 meters tall and 490 meters long, and has a total volume of RCC of approximately 190,000 cubic meters. The foundation at the damsite is sandstone overlain by alluvium.
A complete engineering and geologic assessment was conducted at Wyaralong to characterize the foundation, develop shear strength parameters for bedding planes and other weak layers in the dam foundation, develop potential failure mechanisms, and quantify the amount of reliance that was placed on passive pressure from rock above weak layers in the foundation. Bedding planes and other weak layers in the foundation were critical to the design, and they controlled the size of the dam section. Shear strength properties for bedding planes at the project were developed using a combination of the Barton estimate of shear strength for rough surfaces and field measured roughness values.
Two dimensional and three dimensional stability analyses were conducted for the dam due to the geometry of weak layers in the foundation. In the cases where three dimensional stability analyses were conducted, two dimensional analyses would have been overly conservative. This paper discusses the testing and methods used to perform the engineering and geologic assessment and the stability analysis that was performed for the project. The paper focuses on the challenges encountered during the process and the solutions developed.
106 Senior Project Engineer, Paul C. Rizzo Associates, 500 Penn Center Blvd, Suite 100, Pittsburgh PA 15235 (412) 849 4236 [email protected] 107 Principal Consultant - Civil, Entura, 89 Cambridge Park Drive, Cambridge, Tasmania, Australia, +61 429 705 127, [email protected] 108 Principal Engineering Geologist, SMEC Australia, Level 1, 154 Melbourne St, South Brisbane, QLD Australia +61 413 274 092 [email protected]
77 NOTES
78 NAVIGATION LOCK FOUNDATION DESIGN IN COMPLEX KARST GEOLOGY AT CHICKAMAUGA DAM
Mark S. Elson, P.G.109 Juan Payne, P.G.110 Dewayne Ponds, P.G.111
ABSTRACT
Chickamauga Lock and Dam are located on the Tennessee River in Chattanooga, Tennessee. The project is located in the Valley and Ridge Physiographic Province of East Tennessee on karst prone rock and in a structurally complex geologic setting. A new 600- by 110-foot lock has been designed and will be constructed to replace the existing lock, which is suffering from significant concrete growth problems in the form of alkali carbonate reaction. The new lock foundation design accounts for rock conditions including folded limestone and shale beds, imbricate faulting with associated closely spaced joints, karstic conditions, and 2- to 3-foot thick bentonite beds within and below the excavation. The design solutions for foundation excavation and construction are based on evaluation of the geology at each individual concrete monolith. Precision blasting techniques will be required due to the nature of the geology and the proximity of the existing lock, dam and powerhouse. Rock bolts and shotcrete will be utilized to insure the stability of the excavation during construction. At one critical location, a secant pile wall will be installed to insure the stability of the cofferdam foundation directly adjacent to the lock monolith excavation. Due to the presence of relatively weak and compressible bentonite layers in the foundation rock, many monoliths will be founded on eight-foot diameter drilled shafts. The detailed geologic investigation of the site was also used to design a grouting program for achieving seepage closure of the lock chamber. The lock design was completed during construction of the cofferdam and additional geologic information from the ongoing construction activities was incorporated into the lock foundation design as appropriate.
109 Geologist, US Army Corps of Engineers, Nashville District, 801 Broad St., Estes-Kefauver Building Nashville, TN 37203, [email protected] 110 Geologist, US Army Corps of Engineers, Nashville District, Chickamauga Lock Field Office, 5518 Trailhead Dr., Chattanooga, TN 37415, [email protected] 111 Geologist, ARCADIS US, Inc., 1210 Premier Drive Suite 200, Chattanooga TN 37421, [email protected]
79 NOTES
80 HOWARD A HANSON DAM RIGHT ABUTMENT SEEPAGE FAST TRACK TO INTERIM AND FINAL REPAIRS
Richard E. Smith112 Robert E. Romocki113 Dennis A. Fischer114
ABSTRACT
Howard A Hanson Dam (HHD) completed in 1962 on the Green River in Washington State has had a history of excessive seepage for pool elevations above 1155 feet. HHD is a high hazard dam protecting over 30,000 permanent residents and economic benefits give it a net present value of over $16B. A record pool (elevation 1188.8 feet) was held at HHD on January 9, 2009. During the subsequent post flood drawdown, symptoms indicative of potential piping/internal erosion within the dam’s right abutment were observed including: turbid water discharge from vertical drain well 25 in the right abutment drainage tunnel, a depression formed on the upstream face of the right abutment, and dye placed into the larger of the two depressions as the flood pool was drawn down (pool elevation 1158 feet) exited 300 feet downstream from vertical tunnel well 34 in approximately 5 hours. Interim repairs including a double row grout curtain and improvements to the existing right abutment drainage tunnel were designed and constructed in 2009 to reduce the risk of seepage related failure during the 2009/2010 winter flood season. Additional instrumentation, a geophysical investigation, a geotechnical drilling program, and additional dye tests were conducted to better understand the seepage characteristics of the right abutment. A fast-tracked dam safety modification study (DSMS) was initiated and conducted in parallel with construction and investigation activities to rapidly determine and implement the preferred alternative for returning risk at HHD to tolerable levels.
112Supervisory Geologist, U.S. Army Corps of Engineers, 4735 E. Marginal Way S., Seattle, WA 98134, [email protected] 113Dam Safety Program Manager, U.S. Army Corps of Engineers, 4735 E. Marginal Way S., Seattle, WA 98134, [email protected] 114Supervisory Civil Engineer, U.S. Army Corps of Engineers, 4735 E. Marginal Way S., Seattle, WA 98134, [email protected]
81 NOTES
82 CEMENT BENTONITE SLURRY WALL STRENGTH — TUTTLE CREEK DAM SEISMIC REMEDIATION
Amod K. Koirala, Ph.D.115 Glen M. Bellew, P.E.116 John C. Dillon, P.E.117 David L. Mathews, P.E.118
ABSTRACT
Cement bentonite (CB) slurry walls were constructed as a seismic remediation to stabilize the downstream slope of Tuttle Creek Dam in Manhattan, Kansas. A full-scale test program was conducted to evaluate various slurry mixes and construction techniques prior to main construction. Grout mixes with cement/water (c/w) ratios of 0.3, 0.4, 0.45, and 0.5 were used. Construction equipment in the test program included long-reach and clamshell excavators. Sampling and testing were performed on wet grab samples and core samples. Wet grab samples were obtained from freshly constructed slurry walls and cured in a laboratory. Core samples were obtained from cured walls. Evaluation of the test section results led to the selection of a c/w ratio of 0.5 and the use of a clamshell excavator for seismic stabilization construction. The required peak unconfined compressive strength (UCS) of the cured wall was 300 psi based on stability and deformation modeling. Observations showed UCS of core samples were less than wet grab samples. UCS generally increased with specific gravity and c/w ratio.
1Civil Engineer, US Army Corps of Engineers, 601 E 12th St. Kansas City, MO 64106, [email protected] 2Geotechnical Engineer, US Army Corps of Engineers, 601 E 12th St. Kansas City, MO 64106 , [email protected] 3Project Manager, US Army Corps of Engineers, 601 E 12th St. Kansas City, MO 64106, [email protected] 118Chief, Geotechnical Branch, US Army Corps of Engineers, 601 E 12th St. Kansas City, MO 64106, [email protected]
83 NOTES
84 CONSTRUCTION OF CUT-OFF WALL BY LOW-HEADROOM-CUTTER INSIDE DAM TUNNEL IN CHINA
Wolfgang G. Brunner119 Arthur Bi120 William Chang121 Dung Feng Zong122
ABSTRACT
In the South of Sichuan province a 240 MW Yeleh hydroelectric plant was constructed by Sichuan Nanya River Basin Hydraulic Power Development Company Limited, a state- owned enterprise, and China Gezhou Ba Water & Power Group Company Limited. This project sets out to develop the mountain cascade of the Nanya River, a tributary of the Dadu River, provide superior electricity and adjust flood peak & frequency. The specialist contractor Foundation Engineering Company of China Water Resource and Hydropower (FEC) was awarded the contract for foundation treatment at the right bank, which included the construction of a 75m deep concrete Cut-Off Wall (COW) inside a 6.0m x 6.5m tunnel. The requirement for 19,317m2 COW to be constructed in permeable and very dense gravel/cobble formations and a demanding project program led FEC to adopt Bauer Low Headroom Cutter CBC25/MBC30 in conjunction with Overlap Cutter Joint (OCJ).
119 Professor, Dipl. Ing. Marketing Director, BAUER Maschinen GmbH, BAUER-Str. 1, D-86522 Schrobenhausen, Germany, [email protected] 120 Deputy General Manager, BAUER Technologies Taiwan Ltd., Taipei, Taiwan 121 Senior Engineer, BAUER Technologies Taiwan Ltd., Taipei, Taiwan 122 Deputy Chief Engineer, China Water Group, Beijing, China
85 NOTES
86 WANAPUM DAM FUTURE UNIT INFILL PROJECT
Jim Rutherford123 Cliff Stump124 Gary Mass125 David Lehto126 Randy Nash127
ABSTRACT
Grant County Public Utility District No. 2 (the District) engaged Hatch Associates Consultants Incorporated (Hatch), with concrete engineer Gary Mass as special consultant, to design and help implement the Wanapum Future Unit Infill Project. Barnard Construction Company (BCCI) with specialty subcontractors, including Knight Construction and Supply, Inc (KCC), was selected to construct the project. The objective of the project was the infill of the Wanapum Future Unit Intakes (Wanapum FUI) with mass concrete such that structures would remain stable even if their anchors were to become ineffective. Numerous design and construction innovations and teamwork through a formal partnering program allowed the Wanapum Future Unit Infill Project to be completed ahead of schedule, within the District’s budget limits, while meeting the project design objectives. This paper documents this successful project.
123 Project Engineer, Hatch Associates Consultants, Seattle, WA, [email protected] 124 Project Manager, Barnard Construction, Bozeman, MT, [email protected] 125 Concrete Engineer & Consultant, Cheyenne, WY [email protected] 126 David Lehto, Project Manager, Knight Construction and Supply, Deer Park, WA [email protected] 127 Project Manager, Grant County PUD No. 2, Beverly, WA, [email protected]
87 NOTES
88 FALLS DAM STONEY GATE REPAIRS
Mark J. Gross128 Paul F. Shiers129 Anthony W. Plizga130 Jesse Kropelnicki131 John C. Lyon132
ABSTRACT
Falls Dam is one of the four dams which comprise the Yadkin Project. The Yadkin Division of Alcoa Power Generating Inc. (APGI) owns and operates the Project. The dam and powerhouse were completed in 1919. The dam includes an integral intake/powerhouse, ten Stoney gates, two Tainter gates and a non-overflow gravity section. The Stoney gates are 35 ft wide by 34 ft high. The Stoney gates are operated by individual fixed electric powered screw stem hoists from the spillway deck above.
In August 1994, Stoney gate 4 became stuck during closure and eventually dropped resulting in a failure of the gate’s lifting mechanisms. In August 2004, the binding of Stoney gate 1 resulted in modifications to the gate side rollers to facilitate its operation.
Recently, in December 2008 and June 2009, there were failures on the lifting mechanisms at two other Stoney gates. These occurred after successful completion of full open testing of the gates with the caisson in place in 2008. The more recent incident occurred during gate closure, when the gate apparently got hung up while the gate stem continued to lower, eventually hitting the bottom of the yoke assembly, causing the gate to fall a short distance.
This paper discusses the repairs to the lifting mechanism failures The issues presented in the paper are important in understanding the future repair needs for this type of gate to ensure continuous and safe operation of spillway facilities.
128 Mark J. Gross, Technical Manager, Alcoa Power Generating Inc., Yadkin Division, P.O. Box 576, Badin, NC 28009, (704) 422-5774, [email protected] 129 Paul F. Shiers, Senior Project Manager, PB Americas, Inc., 75 Arlington St. Boston, MA 02116, (617) 960-4990, [email protected] 130 Anthony W. Plizga, Senior Project Engineer, PB Americas, Inc., 75 Arlington St. Boston, MA 02116, (617) 960-4972, [email protected] 131 Jesse Kropelnicki, Lead Engineer, PB Americas, Inc., 75 Arlington St. Boston, MA 02116, (617) 960- 4975, [email protected] 132 John C. Lyon, Senior Civil Engineer, Federal Energy Regulatory Commission, 3700 Crestwood Pkwy, Duluth, GA 30096, (678) 245-3000, [email protected]
89 NOTES
90 REMEDIATION MEASURES IMPLEMENTED TO RESOLVE GATE OPERATION DIFFICULTIES RELATED TO SPILLWAY DECK CONCRETE EXPANSION
Mark J. Gross133 134 Jacob Vozel 135 Bryce Mochrie 136 Stefan Schadinger Paul F. Shiers137
ABSTRACT
Lake Lynn Dam is a 125-ft-high, 1,000-ft-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. Through the years, the project has experienced cracking of the powerhouse, deck and spillway concrete. An Alkali Aggregate Reactivity (AAR) investigation concluded that recent spillway deck deformation problems at Lake Lynn were primarily due to ongoing AAR coupled with the lack of functional expansion joints in the spillway deck and the unbalanced restraint conditions which exist at the powerhouse. In the fall of 2007, six expansion joints were re-established and the cutting effort has successfully freed the joints.
A similar problem was identified at the Falls Development, located near Badin, North Carolina, at Mile 234 on the Yadkin River. The Falls Development is a concrete gravity structure approximately 750 ft long. The Falls Development has been experiencing expansion and cracking at the powerhouse, the spillway deck for the 10 Stoney gates has been bowing upstream, and the piers have been tilting and moving laterally. To help alleviate built-up stresses and associated tilting and lateral movement of the piers, installation of two expansion joints was performed in 2010.
The paper will discuss, for both locations, the repair alternatives evaluated; the results of slot cutting at both developments on gate operation; the impact on the spillway piers including the results of ongoing monitoring programs; construction techniques utilized in this process; and the expected life of the repairs.
133 Mark J. Gross, Technical Manager, Alcoa Power Generating Inc., Yadkin Division, P.O. Box 576, Badin, NC 28009, (704) 422-5774, [email protected] 134 Jacob Vozel, Project Engineer, Allegheny Energy Engineering & Construction 800 Cabin Hill Drive, Greensburg, PA 15601, 724-830-5912, [email protected] 135 Bryce Mochrie, Senior Project Engineer, PB Power, 75 Arlington St. Boston, MA 02116, (617) 960- 4971 [email protected] 136 Stefan Schadinger, Lead Engineer, PB Power, 75 Arlington St. Boston, MA 02116 (617) 960-4976 [email protected] 137 Paul F. Shiers, Senior Project Manager, PB Americas, Inc., 75 Arlington St. Boston, MA 02116, (617) 960-4990, [email protected]
91 NOTES
92 CHEESMAN DAM OUTLET WORKS RENOVATION UNDERWATER CONSTRUCTION ENGINEERING
Jeff Martin, P.E.138 Gordon Harbison, P.E.139
ABSTRACT
Denver Water is in the process of an Outlet Works Rehabilitation at Cheesman Dam. The outlet works consists of tunnels bored through the left abutment at elevations 6,780, 6,690, and 6,645, respectively referred to as the Auxiliary, Mid-Level, and Low-Level Outlets. The rehabilitation was accomplished by installing new stainless steel slide gates through underwater construction diving and at depths up to 210 feet.
The Cheesman Upstream Control project is a phased project spanning several years of design and construction. The project begun in 2007 with the removal of the old balance valve at the low level intake and is anticipated to finish in 2011 with the removal of the old guard valves within the outlet tunnel and replacement of the Larner-Johnson Needle Valve with a new Jet Flow Gate. The entire project includes providing upstream control by means of new slide gates at the inlets to the outlet works tunnels, a new control building housing the hydraulic power for the gates, and finally removal of the guard gates within the outlet tunnel.
The project design was based upon historical information including the original survey note books, asbuilt drawings, and photographs. The high costs of construction diving coupled with the likelihood of differing subsurface conditions required a good partnering effort between the Contractor, Resident Engineer, and Design Engineers. A fast-paced construction schedule (24-hours a day for approximately 15 weeks) required quick analysis of existing conditions and subsequent design changes to avoid lost production time and unnecessary costs.
138 Jeff Martin, Project Manager/Design Engineer, Denver Water Department, 1600 West 12th Ave, Denver, CO 80202 139 Gordon Harbison, Resident Engineer, Krech Ojard & Associates, 3580 Mount Hickory Blvd., Hermitage, PA 16148
93 NOTES
94 GUIDELINES FOR ASSESSING SEDIMENT-RELATED EFFECTS OF DAM REMOVAL
Timothy J. Randle140 Jennifer A. Bountry141 Blair P. Greimann142
ABSTRACT
Dam removal is becoming more common in the United States as dams age and environmental concerns increase. Sediment management is an important part of many dam removal projects, but there are no commonly accepted methods to assess the level of risk associated with sediment stored behind dams. Therefore, the interagency Subcommittee on Sedimentation (SOS) is sponsoring the development of a decision framework for assessing sediment-related effects from dam removals.
The decision framework provides guidance on the level of sediment data collection, analysis, and modeling needed for reservoir sediment management. The framework is based on criteria which scale the characteristics of the reservoir sediment to sediment characteristics of the river on which the reservoir is located. To assist with the framework development, workshops of invited technical experts from around the United States were convened October 2008 in Portland, Oregon and October 2009 in State College, Pennsylvania. The decision framework developed at these workshops is currently being validated with actual dam-removal case studies from across the United States including small, medium, and large reservoir sediment volumes. This paper provides the latest thinking on key components of the guidelines. The paper represents contributions from over 26 entities who have participated in the development of the guidelines. After completion of the case study application, the framework will be finalized and published.
140 Supervisory Hydraulic Engineer, U.S. Bureau of Reclamation, P.O. Box 25007, Denver, Colorado 80225, [email protected] 141 Hydraulic Engineer, U.S. Bureau of Reclamation, P.O. Box 25007, Denver, Colorado 80225, [email protected] 142 Hydraulic Engineer, U.S. Bureau of Reclamation, P.O. Box 25007, Denver, Colorado 80225, [email protected]
95 NOTES
96 SHORT- AND LONG-TERM IMPACTS OF SEDIMENT EROSION FOLLOWING DAM REMOVAL: SEDIMENT AND NUTRIENT LOADING
John R. Shuman143
ABSTRACT
Legacy sediments have, over the last two centuries, accumulated in valley floodplains in the eastern United States from the ubiquitous clearing of forests during 19thcentury agricultural and industrial development. Concomitant with the clearing of forests was the construction of small and medium sized mill dams along streams in the eastern United States. Sediments accumulated behind these mill dams, which in some cases were located every few miles along streams.
As these mill dams have collapsed or been purposefully removed, the legacy sediments that accumulated in the inundated floodplain behind these dams144 have been eroding and the sediments and nutrients carried downstream. A recent study showed five legacy sediment streams with dams long removed were eroding laterally with an average 323 tons of sediment, 747 lbs of nitrogen, and 348 lbs of phosphorus eroded per 1,000 feet of stream over a 4.4 month monitoring period.145
The headcut that develops up the stream channel once a dam has been removed is the comparative short-term sediment impact. The lateral stream bank erosion of legacy sediments accumulated in the impounded floodplain is the long-term impact that will continue to transport sediments and nutrients to downstream waters and estuaries. Dam removal planning and design needs recognize these long-term loading impacts from legacy sediments.
143 Senior Water Resources Scientist, Johnson, Mirmiran and Thompson, 220 St. Charles Way, Suite 200, York, PA 17402. [email protected] 144 Walter, R.C. and D.J. Merritts. 2008. Natural Streams and the Legacy of Water-Powered Mills. Science 39:299-304, January 2008. 145 J. Shuman and C. Shuman. 2011. Stream Bank Erosion and the Chesapeake Bay TMDL – Loading Rates and Bay Model Assumptions. Pages 377-394, in Impaired Waters Symposium 2011: Spanning the Water Quality Continuum – From Standards to TMDLs. January 11-12, 2011, Miami, Florida.
97 NOTES
98 SEDIMENT IMPACTS FROM THE REMOVAL OF SAVAGE RAPIDS DAM
Jennifer A. Bountry, M.S., P.E.146 Yong G. Lai, Ph.D.147 Timothy J. Randle, M.S., P.E.148
ABSTRACT
As part of the dam removal decision making process, scientists and engineers are often asked to predict the impacts from the release of reservoir sediment. Field measurements along with numerical and physical models are typically used to quantify sediment predictions. This information helps make informed decisions about whether to allow the river to erode the reservoir sediment, remove or stabilize the reservoir sediment prior to dam removal, or whether mitigation is needed. When the predictions are followed up with monitoring, our knowledge base increases on the types and level of predictions needed for future dam removals. This paper describes the tools used for prediction and experience gained from a ten-year effort involving sediment predictions and follow-up monitoring for the removal of Savage Rapids Dam on the Rogue River near Grants Pass, Oregon. Unique to the Savage Rapids project was the construction and operation of a new diversion facility and water intake located immediately downstream of the dam, which introduced additional challenges to the dam removal project. For this project, all of the reservoir sediment was allowed to be eroded by the river. Comparisons of numerical 1D and 2D hydraulic and sediment models are made with monitoring data of sediment erosion and deposition. Conclusions are made regarding the applicability of the data collection and modeling efforts accomplished relative to resource management questions associated with sediment impacts from dam removal. Lessons learned are also discussed on the value of incorporating an adaptive management approach.
146 Hydraulic Engineer, Bureau of Reclamation, Technical Service Center, Denver, CO, [email protected] 147 Hydraulic Engineer, Bureau of Reclamation, Technical Service Center, Denver, CO, [email protected] 148 Hydraulic Engineer, Bureau of Reclamation, Technical Service Center, Denver, CO, [email protected]
99 NOTES
100 REMOVE OR REINFORCE: DESIGN ALTERNATIVES TO MEET DAM SAFETY AND FISH PASSAGE REQUIREMENTS AT SAN CLEMENTE DAM
Tom Hepler, P.E149 Blair Greimann, P.E.150 Trish Chapman151 Jeffery Szytel, P.E.152
ABSTRACT
San Clemente Dam was constructed in 1921 at the confluence of the Carmel River and San Clemente Creek, approximately 15 miles southeast of Carmel, California. The 106- foot high thin arch concrete dam is owned and operated by California American Water (CAW), a regulated utility that serves the Monterey Peninsula. The dam impounds a reservoir having an initial storage capacity of 1,425 acre-feet at the spillway crest, elevation 525. The dam was constructed as a point of diversion for surface water from the Carmel River, which would flow to the Carmel Valley Filter Plant and be distributed to CAW’s customers. Since construction, more than 2.5 million yd3 of sediment have accumulated behind the dam, nearly filling the reservoir and essentially eliminating its usable storage capacity. Engineering studies performed in 1992 concluded that the dam could sustain structural damage resulting in the potential loss of the reservoir during a Maximum Credible Earthquake (MCE), and would be overtopped and possibly fail during a Probable Maximum Flood (PMF).
The San Clemente Dam (SCD) Seismic Safety Project was established to meet current standards for maximum earthquake and flood loads for dam safety, and to provide for fish passage at the dam, while maintaining a point of diversion for CAW. A joint Environmental Impact Report/Environmental Impact Statement (EIR/EIS) was prepared in 2006 to address the environmental effects of the project alternatives. The proponent’s proposed project was to strengthen the dam and construct a new fish ladder; however, several alternatives were evaluated. The Carmel River Reroute and Dam Removal alternative would remove the concrete dam and fish ladder, and use the rubble to stabilize sediment at the site. The lower portion of the Carmel River above the dam would be permanently bypassed by excavating a channel through the bedrock ridge that separates the Carmel River from San Clemente Creek. The bypassed portion of the Carmel River would be used as a sediment disposal site for accumulated sediments in both the Carmel River and San Clemente Creek. The lower San Clemente Creek channel would be reconstructed to handle the natural flows from both drainages, while accommodating upstream passage of native steelhead to over 25 miles of spawning and rearing habitat. This paper will explore the two project alternatives and the decisions leading up to the development of final designs to remove the dam.
149 Bureau of Reclamation, PO Box 25007, Denver, CO 80225; [email protected] 150 Bureau of Reclamation, PO Box 25007, Denver, CO 80225; [email protected] 151 State Coastal Conservancy, 1330 Broadway, Oakland, CA 94612; [email protected] 152 Water Systems Consulting, Inc., PO Box 4255, San Luis Obispo, CA 93403; [email protected]
101 NOTES
102 LAKE TOWNSEND DAM REPLACEMENT — CONSTRUCTION UPDATE, GREENSBORO, NC
Robert Cannon, P.G.153 Tillman Marshall153 Gerald Robblee, P.E.153 Frederic Snider, P.G.153 Jerry Gardner, RPR153 Melinda King, P.E.154 Allan Williams, P.E.154 Andrew R. Downs, P.E.155
ABSTRACT
Lake Townsend Dam impounds the primary water supply for the City of Greensboro, North Carolina. The original 44-year old concrete gated spillway is suffering from severe deterioration due to alkali silica reactivity (ASR) and has inadequate hydraulic capacity. After an analysis of repair and replacement options, the selected alternative consists of a new spillway designed with a hydraulic capacity similar to the existing spillway and allowance for embankment overtopping during high flows. The new replacement dam is being constructed immediately downstream of the existing dam. The new spillway consists of a reinforced concrete, seven cycle, 300-ft wide labyrinth with a weir height of 20 feet. Articulating concrete blocks (ACB) will be used to armor the earthen embankments. Underwater demolition of the existing spillway and portions of the embankments will be completed after commissioning of the new dam.
Construction of the new replacement dam began in spring 2009, with an estimated duration of 30 months. Planned commissioning is in November, 2011. The Contractor has faced multiple challenges during construction. Working downstream of a full, operational reservoir entailed additional risk. Diversion of flood flows up to about 10,000 cfs was required. Extensive dewatering was necessary, as soft alluvial clays and loose alluvial sand had to be excavated in the floodplain below the footprint of the new dam. The foundation excavation exceeded 30 feet in the deepest parts. Foundation preparation also required removal of part of the downstream slope of the original embankment. Geotechnical instrumentation was installed to allow performance monitoring of the remaining embankment during foundation excavation and dewatering. Borrow area soils were too wet to achieve the stringent compaction requirements needed for the labyrinth spillway foundation. Several alternatives were tested, and ultimately, cement was added to the site soils at 5% by weight. This cement-modified soil, or CMS, provided numerous benefits during construction.
This paper is a follow-up to a paper entitled Lake Townsend Dam Replacement Project, Greensboro, NC, presented at the April 2009 Annual USSD conference in Nashville, which provided a summary of the site investigations and alternatives assessment.
153 Schnabel Engineering, 11A Oak Branch, Greensboro, NC 27407, [email protected], [email protected], [email protected], [email protected], [email protected] 154 City of Greensboro, 2602 S. Elm-Eugene Street, Greensboro, NC 27406, melinda.king@greensboro- nc.gov, [email protected] 155 Crowder Construction Company, 6409 Brookshire Blvd. Charlotte, NC 28216, [email protected]
103 NOTES
104 EMERGENCY RESPONSE AND REHABILITATION OF SPILLWAY DAMAGE CAUSED BY A MOTHER’S DAY STORM
Stephen L. Whiteside, P.E.156 Tyler C. Dunn, P.E.157 Aaron J. Rubin, E. I. T.158 Richard Dawe159
ABSTRACT
During Mother’s Day weekend in 2006, a 100-year, 48-hour storm dropped more than 11 inches of rain in some regions of Massachusetts, including Walden Pond located in Saugus and Lynn. The west end of the pond in Saugus is impounded by the Walden Pond Outlet Dam, an earthen embankment with a concrete core wall, that is classified as a large, high-hazard potential dam. During the storm, flow into the spillway rose rapidly to a maximum depth of 1.5 feet above the spillway crest which resulted in erosion and damage to the downstream discharge channel. An emergency watch was organized to monitor the erosion occurring at the left training wall and an evacuation plan was established. A Phase I inspection of the dam, performed by CDM in August 2006, concluded that the overall condition of the dam was poor due to the damage and erosion of the spillway. The Massachusetts Office of Dam Safety (ODS) reviewed the Phase I report and ordered the dam owner to perform a Phase II investigation of the dam. The Phase II inspection/investigation prepared by CDM in 2008 evaluated the spillway capacity and embankment slope stability, and provided conceptual remediation options to bring the dam into compliance. CDM prepared the final design contract documents for rehabilitation of the spillway and construction was performed between August and December 2009. This paper will present the extent of the storm’s damage, emergency response, and the constructed design features to ensure repeat storm damage does not occur.
156 Vice President, CDM, 5400 Glenwood Avenue Suite 300, Raleigh, NC 27612 [email protected] 157 Senior Geotechnical Engineer, CDM, 50 Hampshire Street, Cambridge, MA 02139 [email protected] 158 Geotechnical Engineer, CDM, 50 Hampshire Street, Cambridge, MA 02139 [email protected] 159 Superintendent, Lynn Water & Sewer Commission, 390 Parkland Avenue, Lynn, MA 01905 [email protected]
105 NOTES
106 SEEPAGE MODELING FOR EVALUATION OF DEWATERING EFFORTS FOR CONSTRUCTION OF THE COACHELLA CANAL LINING PROJECT
Geraldo R. Iglesia, Ph.D., P.E./G.E.160 Christopher M. Dull, P.E.161 Kenneth A. Steele, P.E.162 Halla Razak, P.E. 163
ABSTRACT
During construction for a new concrete-lined canal to replace a ~35-mile stretch of the existing earthen Coachella Canal, the required dewatering efforts had substantially exceeded initial expectations. Because the new canal had to be constructed without impacting operation of the existing canal, the section between the new and existing canals functioned much like a levee or fill for an elevated canal. With the aid of finite element modeling software, seepage analyses of the site conditions were performed to obtain an understanding of the underlying physical processes that likely contributed to the situation. Based on the seepage modeling results, the presence of a predominantly fine-grained layer overlain by relatively coarser-grained material tended to keep the water seeping from the existing canal into the new canal. These results were mostly corroborated by construction experience in the field, which showed a strong correlation between the location of dewatering drain tile installations and where the predominantly fine-grained soil layer was present.
160 Principal, G2D Resources, LLC, 7966 Arjons Drive, Suite 204, San Diego, California 92126-6361. [email protected]. 161 Vice President, R.W. Beck, Inc., 15373 Innovation Drive, Suite 390, San Diego, California 92128. [email protected]. 162 Consultant, 1740 Burnside Way, Stockton, CA 95207. [email protected]. 163 Colorado River Programs Director, San Diego County Water Authority, 4677 Overland Avenue, San Diego, California 92123-1233. [email protected].
107 NOTES
108 RELIABILITY ANALYSIS OF SIDE SLOPES FOR THE ALL-AMERICAN CANAL LINING PROJECT
Geraldo R. Iglesia, Ph.D., P.E./G.E.164 Christopher M. Dull, P.E.165 Kenneth A. Steele, P.E.166 Kathy L. Schuler, P.E.167
ABSTRACT
Primarily aimed at reducing seepage loss from an existing earthen canal that straddles multiple geopolitical boundaries, the All-American Canal Lining Project (AACLP) was conceived and executed, with authorization by the United States Congress. The AACLP includes building a 23-mile concrete-lined canal parallel to, and in replacement of, a section of the earthen canal. The original project concept envisioned during the project feasibility and environmental studies proposed side slopes with 1.5H:1V (horizontal to vertical) inclination for the new concrete-lined canal. During the formal design phase, the U.S. Bureau of Reclamation (USBR), as the ultimate owner of the AACLP, required the project to provide 2H:1V side slopes. USBR’s only concern in requiring the change was related to the stability of the side slopes during construction rather than for long-term performance or other considerations. This change would have added substantial cost to the project, all of which would have been borne by the San Diego County Water Authority. Additional geotechnical testing and engineering analyses were performed, including triaxial shear tests, which persuaded the USBR to concur with the viability of constructing 1.75H:1V side slopes, at least for two reaches of the project. This paper seeks to summarize the results of the geotechnical analyses performed for the AACLP, which led to a beneficial design change in the constructed side slopes, mitigating the incremental cost impact by about 50 percent. There were no side slope stability issues during construction or during an earthquake of magnitude 7.2 occurring a few months following the end of construction.
164 Principal, G2D Resources, LLC, 7966 Arjons Drive, Suite 204, San Diego, California 92126-6361. [email protected]. 165 Vice President, R.W. Beck, Inc., 15373 Innovation Drive, Suite 390, San Diego, California 92128. [email protected]. 166 Consultant, 1740 Burnside Way, Stockton, CA 95207. [email protected]. 167 Principal Engineer, San Diego County Water Authority, 4677 Overland Avenue, San Diego, California 92123-1233. [email protected].
109 NOTES
110 DESIGN AND CONSTRUCTION OF A SUB-LINER DRAIN SYSTEM FOR THE LUDINGTON PUMPED STORAGE PLANT
Gerald Robblee, P.E. G.E.168 Donald Basinger, P.E. 168 Edward Billington, P.G.168 Frederic Snider, P.G. 168 Robert Cannon, P.G.168 Alex Rutledge, P.G., E.I. 168 Gary Rogers, P.G.168 David Battige169
ABSTRACT
The Ludington Pumped Storage Plant (LPSP) is an 1872 megawatt capacity hydroelectric plant located on the eastern shore of Lake Michigan. The facility was the largest pumped storage plant in the world when it was put into service in 1973. At 842 acres and 27 billion gallons of water, the upper reservoir is still the largest man-made pumped storage reservoir in the United States. Water flow into and out of the upper reservoir is through a massive concrete intake structure. The upper 80 vertical feet of the interior slope of the reservoir is protected by a hydraulic asphaltic concrete liner system (asphalt liner) that contains a gravel drain layer with dike drain pumps for seepage detection and control.
Shortly after construction, a bulge developed in the asphalt liner adjacent to the intake structure. The bulge cracked the upper asphalt layer in 1974, activating the dike drain pumps. Investigations of the bulge area found excessive hydrostatic pressures existed beneath the asphalt liner. A well-point dewatering system was installed in 1975 to relieve sub-liner pressures but further deformation of the asphalt liner occurred. The well-point system was also periodically damaged by ice loading. A new drain system, to be constructed below the asphalt liner, was designed to replace the well-point system. Construction was completed in 2009 by around-the-clock operations during a three-week outage.
168 Schnabel Engineering, 11A Oak Branch, Greensboro, NC 27407, [email protected]; [email protected]; [email protected]; [email protected]; [email protected]; [email protected]; [email protected]. Schnabel personnel offer engineering services in Michigan through a management agreement with AG&E, Inc. 169 Consumer Energy, 3525 S. Lakeshore Drive, Ludington, MI 49431, [email protected]
111 NOTES
112 SAVING INSTITUTIONAL MEMORY AND THE EXTRAORIDNARY COST EFFECTIVENESS OF PROJECT DATABASES
Dr. Donald A. Bruce, C.Eng., D.GE170
ABSTRACT
There is a well known adage to the effect that “those who ignore the lessons of history are condemned to repeat the same mistakes.” This is particularly apt in the current period of dam and levee rehabilitation. In theory, for every project completed during at least the last 50 years, there should be a full “as-built” package of information available for review: such dossiers are extremely important sources of information when planning and undertaking subsequent repairs and modifications. And yet, it is the author’s experience that the expectation does not always — or even often — meet the reality. The completeness of project reporting has often been curtailed by the transfer of key personnel to the “next” project while, in other cases, the package itself — or major portions of it, such as progress photographs, or the original specifications — cannot be located. Such reports also leave the institutional memory banks when personnel retire, and/or their former offices or storerooms are “cleaned out” soon thereafter.
The information contained in contemporary “lessons learned” reports will usually provide clear indications of the cause of the problems which may subsequently develop. Such reports can highlight, with the benefit of hindsight, geological features improperly treated, design assumptions no longer consistent with current practice, and defects made in construction. When these reports are complete and available, their information will allow contemporary engineers to justify not having to spend large sums of money on field research, or having to devote countless hours to “alternatives analysis.” They can therefore be extremely cost effective.
There are two ways in which this historical value can be mined: by industry-wide reviews of specific technology applications, and through project-specific studies of historical records. In recent years the author has compiled two comprehensive databases relating to North American dam rehabilitation — one dealing with prestressed rock anchors, the other dealing with seepage cut-offs. The manner of their funding, execution and contents are summarized in this paper. The paper also illustrates how careful appraisal of such reports has proved invaluable in helping to understand current phenomena and in, therefore, optimizing design time and effort.
170President, Geosystems, L.P., P.O. Box 237, Venetia, PA 15367, U.S.A.; Phone: (724) 942-0570; Fax: (724) 942-1911; Email: [email protected].
113 NOTES
114 STRESS ANALYSIS OF PROPOSED RAISING OF THE BLUE LAKE ARCH DAM
D. Curtis171 F. Feng172 S. Hart173 D. Orbison174
ABSTRACT
Hatch Associates Consultants Inc. was retained by the City and Borough of Sitka, Alaska to perform design engineering services for the Blue Lake Expansion Project. Significant benefits in terms of energy production are apparent if the reservoir level can be increased to el 425. With an increase in height of 83 ft above the current height and 60 ft above the original design height, this represents a 34% increase in height above the original design height.
This paper presents the results of stress analysis which was performed during the design of the dam raise. The finite element program ANSYS was used for the static and dynamic stress analysis of the dam. The static loading on the dam includes dead load, hydrostatic loading including PMF, ice and thermal loads. The dynamic loading includes the design earthquake which has a horizontal PGA of 0.31g. The finite element model includes surface contact element at the vertical contraction joints in the dam and at the concrete/rock interface.
The results of the seismic analysis of the dam indicated that relatively large cantilever tensile stresses develop in both the existing and new dam concrete. However, the results of the analysis with an unbonded horizontal joint between the existing and new concrete showed significantly reduced earthquake induced tensile stresses.
171 Senior Civil Engineer, Hatch Ltd., Niagara Falls, Ontario, Canada, [email protected] 172 Senior Civil Engineer, Hatch Ltd., Niagara Falls, Ontario, Canada, [email protected] 173 Project Manager, Hatch Associates Consultants, Inc., Seattle, WA, [email protected] 174 Engineer for the city and Borough of Sitka, AK, [email protected]
115 NOTES
116 REBUILDING THE SILVER LAKE DAM
Jeffrey M. Bair, P.E.175 Benjamin K. Ferguson, P.E.176 Jeffrey E. Krueger177 Robert J. Meyers178
ABSTRACT
Silver Lake Dam was rebuilt following extensive engineering analyses to fully- understand the 2003 activation of the fuse plug spillway which nearly emptied the reservoir. Along the way and to support the overall cost of the rebuild, studies were undertaken to fully understand the project benefits which include hydro-power, augmentation of low flows, maintaining recreation pool levels downstream, and flood control. Various approaches were developed to reduce the overall cost of remediation to match the perceived project benefits. This was accomplished within the bounds of the existing project license which reduced both schedule and cost.
The need for remediation stems from inadequate spillway capacity as a result of updated flood studies conducted in early 2000. A previous remediation to augment spillway capacity in the form of a fuse-plug spillway was completed in 2002. Less than one year later, a significant rainfall event coupled with seasonal snow melt activated the fuse-plug and essentially drained the impoundment.
From 2003 to 2008, engineering analyses were completed to evaluate whether to rebuild the Silver Lake Dam, and if so, what additional items could be modified to minimize construction costs while providing for a safe dam under FERC guidelines. Items such as spillway crest elevation, energy dissipation alternatives, and embankment raising configurations were evaluated as to their merits and effects not only on Silver Lake, but on the Dead River Hydroelectric Project as a whole. By December of 2008, the rebuild was complete and Silver Lake began the refill process. This paper examines both the engineering and construction challenges faced in the years of 2003 through 2008.
175 Practice Leader – Dams, Black & Veatch Corporation, 750 Holiday Drive, Pittsburgh, PA 15220, [email protected] 176 Project Engineer, Paul C. Rizzo Associates, Inc. 500 Penn Center Blvd., Suite 100, Pittsburgh, PA 15235, [email protected] 177 Project Manager, Integrys Business Support, LLC, 700 North Adams Street, P.O. Box 19001, Green Bay, WI, 54307-9001, [email protected] 178 Project Manager, Upper Peninsula Power Company, 500 North Washington Street, Ishpeming, MI 49849, [email protected]
117 NOTES
118 INVESTIGATING AND REHABILITATING A 100-YEAR OLD EARTHEN EMBANKMENT DAM IN SOUTHEASTERN MASSACHUSETTS
Stan S. Sadkowski, III, P.E.179 Vernon R. Kokosa, P.E.180 Luke D. Norton181 George Rogers182 Alan Swieder183
ABSTRACT
As the world’s largest cranberry grower, A.D. Makepeace Company (ADM, Owner) owns and operates over 20 dams ranging from small, non-jurisdictional to large, high hazard. To help meet their regulatory needs and for future planning and maintenance, Sanborn, Head and Associates, Inc. (Sanborn Head) provided Phase II investigation and inspection services, strategies for dam hazard re-classification and regulatory compliance, as well as, professional services for dam repair permits (Wetlands Protection Act, USACE Section 404, and Massachusetts DCR Chapter 253). Together with McNamara/Salvia, Inc., Sanborn Head provided design and construction recommendations for one of ADM’s larger dams, the Glen Charles Pond Dam, a large, significant hazard, 420-foot long, 20-foot tall earthen embankment dam with a 30-foot wide concrete ogee spillway. Glen Charles Pond Dam, located in southeastern Massachusetts, controls the outflow of Glen Charles Pond to allow for the operation of over 130 acres of cranberry bogs. Due to the dilapidated condition of the concrete spillway and deficiencies along the embankment, it was listed to be in Poor condition and out of compliance with Commonwealth of Massachusetts dam regulations.
This paper presents the case history of Glen Charles Pond Dam, from our Phase II Inspection and Investigation through conceptual and final design to construction. It also details the investigatory work, describes engineering studies performed to revise the dam’s hazard classification, conceptual design alternatives, the final design plan, and design changes during construction. The paper will highlight some of the challenges associated with rehabilitating and reconstructing the 100-year old concrete spillway and training walls.
179Senior Project Manager (Young Professional), Sanborn, Head & Associates, Inc., 1 Technology Park Drive, Westford, MA 01886, [email protected] 180Vice-President, Sanborn, Head and Associates, Inc., [email protected] 181Project Engineer (Young Professional), Sanborn, Head and Associates, Inc., [email protected] 182Senior Vice President, A.D. Makepeace Company, 158 Tihonet Road, Wareham, MA 02571, [email protected] 183 Senior Field Engineer, McNamara/Salvia, Inc., 160 Federal Street, 5th Floor, Boston, MA 02210, [email protected]
119 NOTES
120 LESSONS LEARNED AT THE TAUM SAUK REBUILD
Paul C. Rizzo, Ph.D., P.E.184 Carl Rizzo185 John Bowen186
ABSTRACT
The Authors served in key roles for the design and rebuild of the Dam for the Taum Sauk Rebuild Project between 2007 and 2009. Taum Sauk is the largest RCC Dam in the United States and has a symmetrical cross-section with conventional concrete faces upstream and downstream. The curvilinear shape and the cross-section presented a number of placement issues. In addition, a large number of “Lessons” were learned because of the rapid construction schedule, highly variable temperatures, highly confined working space, numerous details related to waterstops, construction joints and crest-to- gallery drains, foundation preparation, lift maturity, bedding mixes, crack repairs, and the conventional concrete upstream face. The authors discuss these issues from the perspective of the Designer, Construction Manager, and Contractor.
184 President/CEO, Paul C. Rizzo Associates, Inc., Pittsburgh, PA 15235, [email protected] 185 Vice President of Construction Management, Paul C. Rizzo Associates, Inc., Pittsburgh, PA 15235, [email protected] 186President, ASI Constructors, Inc., Pueblo West, CO 81007, [email protected]
121 NOTES
122 STABILITY ISSUES AT INTAKE UD, HONG KONG
A. Rowland187 C.F. Wan188 J. Dominic Molyneux189
ABSTRACT
The High Island water supply reservoir, named one of the Ten Engineering Wonders in Hong Kong, was created in the 1970s by constructing two 350-foot-high rockfill dams at each end of a sea water channel open to the South China Sea. An extensive catchment collection system diverts water from the surrounding area into a tunnel network feeding the reservoir. Intake structure UD is a 30-foot-high siphon weir. The structure is constructed of mass concrete with reinforced concrete used only in the siphon inlets and hood. Staff of the Water Supplies Department (WSD) noted relative movement between adjacent siphon monoliths and, after draining the basin, horizontal cracking of the upstream face. The evidence was consistent with a stability failure of the structure. However, conventional analysis showed that the factors of safety for all load conditions were adequate and in line with normal design criteria. WSD carries out regular inspections of its structures and no exceptional events that could have led to increased loadings had been recorded. This paper describes the investigations undertaken to establish the failure mechanism as well as the remedial measures proposed.
187 Technical Director, Head of Dams and Reservoirs Europe, Black & Veatch, Redhill RH1 1LQ, United Kingdom, [email protected] 188 Technical Director, Regional Practice Leader - Dams, Levees and Reservoirs, Black & Veatch Australia, Suite 2, 32/F. 100 Miller Street, North Sydney, NSW 2060, Australia, [email protected] 189 Regional Practice Leader – Heavy Civil Engineering, Black & Veatch Corp, 217 Edmor Road, West Palm Beach, FL 33405, USA, [email protected]
123 NOTES
124 PERFORMANCE OF FLOOD-TESTED SOIL-CEMENT PROTECTED LEVEES
Kenneth D. Hansen, P.E.190 Dennis L. Richards, P.E.191 Mark E. Krebs, P.E.192
ABSTRACT
Although there were some early projects using soil-cement to protect levees or banks dating back to 1965, large scale use of soil-cement bank protection did not occur until the late 1970’s and early 1980’s in the Tucson area. Following its excellent performance during the October 1983 flood of record in Tucson, the use of soil-cement to protect mainly sandy riverbanks soon spread to other urban areas of Arizona, New Mexico, Colorado and California.
This paper will present the results of the performance of soil-cement protected levees during the following five major floods: - The October 1983 flood on the Santa Cruz and Rillito Rivers in Tucson, AZ - The January 1993 flood on the same rivers in Tucson, AZ - The January 1993 flood on the Salt River in the Phoenix, AZ area - The January 2005 flood on the Santa Clara River at Santa Clarita and Fillmore, CA - The July 2006 flood on the Rillito River in Tucson, AZ
Soil-cement protected banks are typically built to contain the 1 in 100-year event. In two of these cases, the measured flow exceeded the 100-year flood. Thus the soil-cement protection was overtopped and the levee material behind the soil-cement exposed to erosion.
In addition, in several of the events, high flows caused erosion beneath the scour depth to which the soil-cement was placed. The performance of the protection in each case will be presented.
The case history at Phoenix will focus on the resistance of cement-stabilized alluvium (as soil-cement along the Salt River in Maricopa County is called) to very abrasive flow while the performance of a buried soil-cement design in California will be presented.
190 Individual Consultant, 6050 Greenwood Plaza Blvd. – Suite 100, Greenwood Village, CO 80111; [email protected] 191 Senior Project Manager, Ayres Associates, 1500 North Priest Drive – Suite 107, Tempe, AZ 85281; [email protected] 192 President, Pacific Advanced Civil Engineering, Inc. (PACE), 17520 Newhope Street – Suite 200, Fountain Valley, CA 92708; [email protected]
125 NOTES
126 GIBE III: ZIGZAG GEOMEMBRANE CORE FOR ROCKFILL COFFERDAM IN ETHIOPIA
G . Pietrangeli193 A . Pietrangeli193 A . Scuero194 G . Vaschetti195 J. Wilkes196
ABSTRACT
The third phase of the Gibe cascade, known as Gibe III HPP, with an installed power of about 1870 MW will be one of the largest hydropower plants in Africa. The plant includes a 240 m high RCC dam and a 50 m high rockfill cofferdam on the Omo river. Studio Ing. G. Pietrangeli S.r.l. is the designer. The cofferdam body is made with river gravel, basalt and trachyte. The impervious core of the cofferdam is made with a flexible 3.5 mm thick PVC geomembrane sandwiched between two layers of 1200 g/m2 geotextile that protect it against puncturing by the fill materials. The geomembrane core solution was adopted in light of the necessity to finalize the approximately 500,000 m3 embankment during the short, 6 month span of the dry season (average river flow is 200 m3/s), since the rainy season has average flow is 1000 to 1500 m3/s with peak floods reaching 5200 m3/s, in a return period of Tr=30 years. The geomembrane waterproofing system, designed to follow step by step, the construction of the rockfill cofferdam, will create a continuous impervious barrier running in a zigzag pattern, along the longitudinal axis of the dam from the bottom cut-off up to the crest. The body of the dam has been constructed in alternated sections starting from the center line defined by the longitudinal axis, upstream and downstream directed. The waterproofing system has been placed on the face of each section toward the center of the dam, finished with a 1V:1H slope. The paper describes the design rationale and details, and steps of construction and geomembrane installation.
193 Studio Ing. G. Pietrangeli S.r.l., Via Cicerone 28, 00193 Rome, Italy, [email protected] 194 Carpitech, S.A., Via Passeggiata 1 Balerna, 6828. Switzerland, [email protected] 195 Carpitech, S.A., Via Passeggiata 1 Balerna, 6828. Switzerland, [email protected] 196 Carpi USA, 4370 Starkey Rd, Roanoke, VA, USA 24018, [email protected]
127 NOTES
128 DESIGN AND CONSTRUCTION OF NEMISCAU-1 DAM, THE FIRST ASPHALT CORE ROCKFILL DAM IN NORTH-AMERICA
Vlad Alicescu197 Jean-Pierre Tournier198 Pierre Vannobel199 Véronique Moore200
ABSTRACT
After using for more than 50 years the glacial till as waterproofing material for its embankment dams, Hydro-Québec was looking forward to develop new dam concepts, mainly for La Romaine HEP, where natural waterproofing materials are scarce, of poor quality or situated at long distances from the construction site. In order to do so, Hydro- Québec has decided to design and construct the Nemiscau-1 Dam as a prototype Asphalt Core Rockfill Dam. Being one of the retaining structures of the Eastmain - Rupert Diversion project, situated in the North of Quebec, the design of this 15 m high dam follows the experiences and standards of many constructed Hydro-Québec dams, which have a very good record. The given dam site, geology and materials were well suited for a dam with an asphalt core. The paper will present the design criteria, technical specifications and finally, the construction of the dam, which started in May, 2008 and was completed by October 2008, ahead of the schedule and within the contractual budget.
197 Eng., MBA, Planning of Development Projects, Hydro-Québec, 75, Boul. René Lévesque O, Montréal, Québec, Canada H2Z 1A4, [email protected], [email protected] 198 Eng., PhD, Expertise HEP, Hydro-Québec, 855, Ste-Catherine E, Montréal, Québec, Canada H2L 4P5, [email protected] 199 Eng., M. Eng., Geotechnical specialist, SEBJ, 855, Ste-Catherine E, Montréal, Québec, Canada H2L 4P5, [email protected] 200Jr. Eng., M. Eng., Engineer – soils and asphalt, Groupe Qualitas Inc., 50, William Dobell Street, Baie- Comeau, Québec, Canada, G4Z 1T7, [email protected]
129 NOTES
130 CENTRAL FILTER INSTALLATION FOR THE REHABILITATION OF BUCKEYE FRS NO. 1
201 Sam Sherman, P.E. Lawrence Hansen, Ph.D., P.E.202
ABSTRACT
Buckeye Flood Retarding Structure (FRS) No.1 is one of a system of three earthen dams built within the Buckeye Watershed in Maricopa County, Arizona. This 7.1 mile long dam is located north of the Interstate Highway 10 (I-10) in Buckeye, Arizona and southwest of the White Tank Mountains. The dam was built in the 1970s by the Soil Conservation Service (now the Natural Resource Conservation Service) to provide flood protection to the I-10 and downstream farmland. The dam is operated and maintained by the Flood Control District of Maricopa County (District). Several dam safety deficiencies were identified at this dam and a rehabilitation project, the Buckeye FRS No. 1 Rehabilitation Project is in progress to address them. The project consists of the overall rehabilitation of the Buckeye FRS No.1 to maintain flood control benefits, correct the current deficiencies, and comply with state dam safety requirements.
The work presented includes the methodology for alternatives analysis, the evaluation factors used to complete the alternatives analysis, and the selection of a final alternative for the design of the rehabilitation project. The final outcome of the selection process was to rehabilitate the dam by constructing a central filter. The paper briefly describes the details of the proposed central filter installation for the project.
201 Dam Safety Engineer, Flood Control District of Maricopa County, Phoenix, AZ 85009, [email protected] 202 Principal Geotechnical Engineer, AMEC Earth & Environmental, Tempe, Arizona 85284, [email protected]
131 NOTES
132 FIRST INTRODUCTION OF GREG HANSON’S « JET EROSION TEST » IN EUROPE : RETURN ON EXPERIENCE AFTER 2 YEARS OF TESTING
Patrick Pinettes203 Jean-Robert Courivaud204 Jean-Jacques Fry204 Fabienne Mercier203, 205 Stéphane Bonelli205
ABSTRACT
Earthen hydraulic structures are known to be subject mainly to erosion processes. The vulnerability to these phenomena cannot be quantified with the identifications that are commonly used to assess the level of risk of hydraulic structures. geophyConsult thus introduced in 2009 to Europe the Greg Hanson’s « Jet Erosion Test », which dynamically impacts soils and quantifies the erosion parameters. The present paper presents the experiences and lessons learned from the application of this method, based on over 100 tests carried out in 2 years.
First, we show how this series of « Jet Erosion Test » in Europe met an actual demand, in France.
Second, we focus on how the introduction of the « Jet Erosion Test » in Europe led to further refinements of the test procedures, so that the test can be carried out more broadly. This led to the development of a new mathematical method for deriving the erosion parameters from experimental data (based on the same physical assumptions and equations as Mr. Hanson’s) and to an estimate of the mathematical uncertainties associated with the modelling. geophyConsult, eDF and other partners plan to launch a new erodimeter in 2011. It will include, among others, a sensor for the measurement of the scour depth, and thus reduce the running costs.
203 geophyConsult SAS, B.P. 231 – 73 374 Le Bourget du Lac, France, [email protected] 204 eDF-CIH, Savoie Technolac – 73 373 Le Bourget du Lac, France 205 Cemagref UR Ouvrages hydrauliques et hydrologie, 3275 route Cézanne – 13 182 Le Tholonet, France
133 NOTES
134 APPLICATION OF ‘A UNIFIED METHOD FOR ESTIMATING PROBABILITIES OF FAILURE OF EMBANKMENT DAMS BY INTERNAL EROSION AND PIPING’ — A UK PERSPECTIVE
M. Eddleston206 P. Rigby207 R. Margrett208 P. J. Mason209 K. D. Gardiner210 J. Cyganiewicz211
ABSTRACT
Many UK dam owners consider that the greatest potential threat to their old embankment dams is internal erosion or piping. However, evaluation of the potential for internal erosion to occur is complex and necessitates the use of risk analysis methodologies to provide an estimation of failure probabilities. This often requires subjective judgments best made by a very limited number of experienced dam engineers using expert elicitation methods. To date, such techniques have not generally been adopted in the UK.
A major UK dam owner, United Utilities, has been using Portfolio Risk Assessment (PRA) since 2002 to evaluate the vulnerability of their dams to major threats including piping and internal erosion using methods developed at the University of New South Wales, Australia. Remedial works have been proposed on a number of dams but the degree of risk reduction likely to be achieved by these works cannot be ascertained at the Portfolio level. It was recognized that a robust method was needed to estimate dam performance before and after remedial works to justify the expenditure.
In 2008 UU were given permission by the US Bureau of Reclamation (Reclamation) and the US Army Corporation of Engineers (USACE to trial the “Unified Method for Estimating Probabilities of Failure of Embankment Dams by Internal Erosion and Piping (aka “Toolbox”).
The Toolbox probability estimates are being used to refine the ranking of those dams closest to the top of UUs PRA assessments - i.e. those with the highest probability of failure. From this review the requirement for and the cost effectiveness of proposed remedial works are assessed using published UK Health and Safety Executive Guidelines.
206 Technical Director, Ground Engineering, MWH, Dominion House, Temple Court, Warrington Cheshire WA3 6GD. [email protected]. 207 Principal Geotechnical Engineer. Haweswater House, Lingley Mere Business Park,Great Sankey Warrington, Cheshire.WA5 3LP. [email protected], 208 Design Manager, MWH, Clearwater 2, Lingley Mere Business Park, Lingley Green Avenue, Great Sankey, Warrington WA5 3LP. [email protected]. 209 Technical Director, Dams and Hydro Power, Terriers House, Amersham Rd, High Wycombe, Buckinghamshire HP13 5AJ. [email protected]. 210 Regional Safety Manager, United Utilities Water PLC, Thirlmere House, Lingley Mere Business Park, Lingley Green Avenue, Great Sankey, Warrington WA5 3LP. [email protected] 211 Geotechnical Engineering Consultant, Cyganiewicz Geotechnical, LLC, 15378 W Iliff Drive, Lakewood, CO 80228. [email protected].
135 NOTES
136 PINE CREEK DAM — ISSUES, INVESTIGATIONS, AND INTERIM MEASURES
D. Wade Anderson, P.E.212 Kathryn A. White, P.E.213
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 will provide background information on the dam, potential concerns with the dam, ongoing investigations conducted at the project location, and will discuss results of investigations, interim risk reduction measures to address issues of concern, and provides conclusions drawn from the investigations.
212 Dam Safety Program Manager, U.S. Army Engineer District, Tulsa, OK 74128, [email protected] 213 Lead Geotechnical Engineer, U.S. Army Engineer District, Tulsa, OK 74128, [email protected]
137 NOTES
138 MODELING, MAPPING, & CONSEQUENCE PRODUCTION CENTER / ILLUSTRATED GUIDE TO MMC INUNDATION MAPPING GRAPHIC SPECIFICATION
Joey M. Windham, P.E214 Will Breitkreutz215
ABSTRACT
The Modeling, Mapping, and Consequences Production Center (MM&C) is responsible for accomplishing hydraulic modeling, mapping, and consequences analysis for USACE Dams in support of the USACE Dam Safety and Critical Infrastructure Protection and Resilience (CIPR) Programs. The MM&C is managed by the Vicksburg District and supplemented by virtual staff of 100 plus members including technical specialists, hydraulic engineers, economists, and Geographical Information System (GIS) professionals from across USACE. The following are the major initiatives for the MM&C: develop consistent and scalable dam failure models and consequence estimates for Corps dams, develop reliable mapping products to meet multiple objectives and apply, test and advance modeling and GIS mapping capabilities of the USACE.
The MM&C formulation was initiated in September 2008. Since conception the MM&C has modeled 200 plus Corps Dams including Flood Control Dams, Navigation Dams, and Hurricane Barriers. The MM&C is continually developing and refining hydraulic modeling methods and consequence estimates techniques by incorporating lessons learned, researching sensitivities of modeling parameters, researching applications of new technologies, and working with Corps of Engineers Research Centers to advance modeling software and refining dam failure modes. In addition to dam failure modeling the MM&C is researching the best methods for modeling levee failures and resulting consequence estimates and inundation mapping, and will begin analysis in 2011.
214Civil Engineer, United States Army Corps of Engineers, Vicksburg District, 4155 East Clay Street,Vicksburg, MS 39183, [email protected] 215GIS Professional, United States Army Corps of Engineers, Kansas City District, 601 East 12th Street, Kansas City, MO, 39183
139 NOTES
140 USACE MODELING, MAPPING, & CONSEQUENCE CENTER — BLUESTONE DAM FAILURE ANALYSIS & LESSONS LEARNED
Edward L. Stowasser, P.E.216
ABSTRACT
The U.S. Army Corps of Engineers (USACE) Office of Homeland Security (OHS) tasked the Hydraulics and Hydrology (H&H) Community of Practice to develop and execute, a dam failure flood inundation mapping initiative for Bluestone Dam. This effort supports the risk assessment responsibilities of USACE Dam Safety program and USACE Office of Homeland Security’s critical infrastructure program.
Estimating consequences, including life loss and economic impacts, for both dam failure and non-failure conditions are critical for risk assessment. For the Bluestone Dam project area, a geo-referenced HEC-RAS hydraulic model was developed and utilized to simulate failure and non-failure conditions under normal to extreme hydrologic loading conditions. Additionally, a HEC-FIA (Flood Impact Analysis) model was developed to aid in consequence estimation.
During the modeling, mapping, and consequence analysis several assumptions, difficulties, and lessons learned were documented. These include the importance of incorporating bathymetric data; calculating and communicating flood wave arrival times; coordinating with state and county emergency managers for study input and map reviews; incorporating downstream navigation dams and non-federal dams; and including a inflow design flood hydrograph to model dam failures during flood control operations.
The Bluestone Dam inundation project has helped identify various improvements that have been incorporated into the USACE Modeling, Mapping, and Consequences (MM&C) production practices. Current production standards are documented within the USACE Modeling, Mapping, and Consequences Production Center Standard Operating Procedures (SOP).
216Hydraulic Engineer, U.S. Army Corps of Engineers, Huntington, WV 25701, [email protected]
141 NOTES
142 PROACTIVE OWNERSHIP OF THE PEDLAR DAM LEADS TO TIMELY AND COST-EFFICIENT SOLUTIONS WITH CHANGING REGULATIONS
Dennis Hogan, P.E.217 Greg Zamensky, P.E.218
ABSTRACT
Significant amendments to the Virginia dam safety regulations, enacted September 2008, include safety standards similar to the federal standards and the standards of many other states. Changes to the dam safety regulations include, but are not limited to: ¾ reclassifying dams as high, significant or low hazard potential, instead of I through IV ¾ increased spillway design flood (SDF) criteria ¾ more rigorous certification renewal requirements ¾ dam break inundation zone mapping ¾ incorporation of the inundation zone maps into local zoning and land use plans ¾ stronger Emergency Action Plans and annual drills with local emergency responders ¾ more rigorous construction/alterations permit process ¾ additional administrative fees The Pedlar Dam is owned by the City of Lynchburg, with a regular Operations and Maintenance certificate from the Virginia Department of Conservation and Recreation (DCR), Dam Safety Group, as a Class II (or significant hazard), medium size dam. In preparation for certificate renewal, engineering analyses were performed to determine the proper hazard classification, ability of the dam to withstand the associated SDF, and dam alterations that would be needed to meet the new requirements.
The City’s Utilities Department is proposing dam alterations in the City’s Capital Improvement Plan. These alterations would include general concrete repair, dredging and removal of sediment and debris from inside and outside the intake tower, repair of gates, addition of trash racks, and the above improvements required to meet the amended dam safety regulations. It is anticipated that the City will apply for an Alterations Permit by submitting a design report in accordance with the regulations.
217 Senior Project Engineer, Geo-Engineering Department – Dams, Levees, and Reservoirs Practice, Black & Veatch Water, Philadelphia, PA 19106, [email protected] 218 Regional Practice Leader, Geo-Engineering Department – Dams, Levees, and Reservoirs Practice, Black & Veatch Water, Gaithersburg, MD 20879, [email protected]
143 NOTES
144 APPROACHES TO ESTIMATING CONSEQUENCES DUE TO LEVEE FAILURE, ST PAUL LEVEE SYSTEM BETA TEST
Corby Lewis, P.E.219 Patrick Foley, P.E., D.WRE220 Mitch Laird221 Kari Layman, P.E.222 Jeff McGrath223 Andrew Sander224
ABSTRACT
A Potential Failure Mode Analysis (PMFA), which has become a standard tool for many dam safety agencies, is essential in the evaluation of levee safety as well. Prior to a PFMA, it is important to have an understanding of the hydrologic loadings and magnitude of the consequences of failure. Estimating the consequences of failure for a levee system becomes complex when factors such as likely failure location(s), breach size(s), evacuation times, and appropriate fatality rates are considered. This paper presents the approaches that were taken to estimate consequences for the City of St Paul levee system in advance of the PFMA.
An unsteady HEC-RAS (River Analysis System) model of the Mississippi River including the St Paul Levee system was created using a combination of LiDAR elevation data, existing HEC-2 cross sections, and recently surveyed existing levee elevation data. The model was then used to simulate failure and non-failure conditions for various hydrologic events. The resulting stage hydrographs within the interior protected area, which was modeled as a single storage cell, were then used along with US Census HAZUS data in a HEC-FIA (Flood Impact Analysis) model to estimate loss of life and other consequences.
Although the approach utilizing HEC-RAS and HEC-FIA models produces reasonable results in the case of the St Paul levee system, it does not attempt to properly simulate the overland spreading of flow in the interior area. Thus, as an alternative the interior area was also modeled with the two dimensional software FLO-2D. This approach enabled the application of an estimate of the loss of life that considered the effects of velocity and rate of rise at distinct locations throughout the floodplain.
219 Hydraulic Engineer, US Army Corps of Engineers, St Paul, MN, [email protected] 220 Hydraulic Engineer, US Army Corps of Engineers, St Paul, MN, [email protected] 221Economic Regional Technical Specialist, US Army Corps of Engineers, Nashville, TN, [email protected] 222 Hydraulic Engineer, US Army Corps of Engineers, St Paul, MN, [email protected] 223 Economist, US Army Corps of Engineers, St Paul, MN, [email protected] 224 Hydraulic Engineer, US Army Corps of Engineers, St Paul, MN, [email protected]
145 NOTES
146 A CONSISTENT APPROACH FOR VULNERABILITY ASSESSMENT OF DAMS
Yazmin Seda-Sanabria225 M. Anthony Fainberg 226 Enrique E. Matheu, PhD 227
ABSTRACT This paper presents a consistent methodology for security vulnerability assessment of dams. The quantification of vulnerability is based on the systematic characterization of the different defensive layers protecting the facility and its critical components. This characterization takes into account various possible attack modes (ground, water, cyber, etc.) and considers the potential asymmetric configuration of the security measures with respect to the different possible approaches (left bank vs. right bank, etc.). For any selected attack scenario, the corresponding vulnerability is numerically defined as the probability of a successful attack that is able to sequentially defeat each defensive layer protecting the intended target. The probability of successful attack against each one of the individual defensive layers is predetermined using a rigorous expert elicitation process. The resulting methodology is easy to implement and facilitates the consistent comparison of vulnerability assessment results across a large portfolio of dams.
225 Program Manager, Critical Infrastructure Protection and Resilience Program, Office of Homeland Security, U.S. Army Corps of Engineers, Headquarters, Washington, DC 20314. 226 Adjunct Research Staff Member, Strategy Forces, and Resources Division, Institute for Defense Analyses, Alexandria, VA 22311. 227 Chief, Dams Sector Branch, Sector-Specific Agency Executive Management Office, Office of Infrastructure Protection, U.S. Department of Homeland Security, Washington, DC 20528.
147 NOTES
148 DEVELOPMENT OF A PRACTICAL TABLETOP EXERCISE SUPPORT TOOL
Michael Bowen 228 Robert C. Hughes, PE 229 Alan Patterson 230 Enrique E. Matheu, PhD 231
ABSTRACT
The Office of Infrastructure within the U.S. Department of Homeland Security, as the Dams Sector-Specific Agency, coordinated with public and private stakeholders to develop the Dams Sector Tabletop Exercise Toolbox (DSTET). This toolbox aims to assist dam stakeholders in planning and conducting security-based tabletop exercises in accordance with the Homeland Security Exercise and Evaluation Program guidelines. The purpose of DSTET is to provide owners/operators and their public safety partners with the capability to identify and address security gaps, threats, issues, and concerns pertaining to their respective facilities, with a focus on information sharing and coordination during incidents.
The DSTET allows participants the opportunity to identify and examine the issues and challenges presented via two unique exercise scenarios provided as part of the toolbox. The toolbox is designed to allow exercise planners to tailor the details of the exercise to suit the specific needs of their individual facilities. Toolbox contents include exercise planner instructions, facilitator and evaluator handbook, situation manuals, facilitator briefing slides, sample invitation letters, sample feedback forms, videos, and exercise reference materials. This paper describes the development, application, and content of the DSTET.
228 Security Specialist, Dams Sector Branch, Sector-Specific Agency Executive Management Office, Office of Infrastructure Protection, U.S. Department of Homeland Security, Washington DC 20598. 229 Civil Engineer, Dams Sector Branch, Sector-Specific Agency Executive Management Office, Office of Infrastructure Protection, U.S. Department of Homeland Security, Washington DC 20598. 230 Program Analyst, Dams Sector Branch, Sector-Specific Agency Executive Management Office, Office of Infrastructure Protection, U.S. Department of Homeland Security, Washington DC 20598. 231 Chief, Dams Sector Branch, Sector-Specific Agency Executive Management Office, Office of Infrastructure Protection, U.S. Department of Homeland Security, Washington DC 20598.
149 NOTES
150 EMERGENCY ACTION PLANNING — INUNDATION MAP UPDATES USING A GEOGRAPHIC INFORMATION SYSTEM
Kareem A. Bynoe232 Ray Barham233 Michael Woodruff234 Shirley Williamson235 Paul F. Shiers236
ABSTRACT
Emergency action planning is a critical component in the management of all medium and high hazard hydroelectric facilities. An effective emergency action plan (EAP) could mean the difference between a dam failure that results in a major catastrophe with many casualties and one where few or no casualties occur. Although having an EAP will not guarantee the prevention of casualties, it will help facility owners be reasonably prepared for a dam failure emergency.
Inundation maps are a key component of an EAP. The Federal Energy Regulatory Commission (FERC) states that the purpose of an inundation map is “… to show the extent and timing of expected flooding from a dam failure”. Although unlikely, recent dam failures serve as a reminder that adequate emergency planning and inundation maps are of importance.
FERC has issued new guidelines for EAP inundation mapping that includes providing data in a geographic information system (GIS) compliant format. To implement these changes the licensee must consult with the various state and local emergency management agencies (EMAs) to understand their GIS capabilities and specific inundation mapping needs.
The purpose of this paper is to present an overview of the new FERC guidelines; discuss the major advantages of GIS based inundation maps; outline the steps that Alcoa Power Generating Inc (APGI) used in their recent inundation map updates; describe the GIS capabilities of the EMAs and APGI’s consultation process; and review the current progress made by APGI to provide a more usable tool that meets a wide range of needs.
232 Lead Engineer, PB Americas, Inc., Boston, MA 02116, [email protected] 233 Technical Manager, Alcoa Power Generating Inc., Tapoco Division, Alcoa, TN 37701, [email protected] 234 Civil Engineer, Federal Energy Regulatory Commission, Duluth, GA 30096, [email protected] 235 Senior Project Engineer, PB Americas, Inc., Boston, MA 02116, [email protected] 236 Senior Project Manager, PB Americas, Inc., Boston, MA 02116, [email protected]
151 NOTES
152 21ST CENTURY DAM SAFETY PROGRAMS IN THE U.S. DEPARTMENT OF THE INTERIOR
M. E. Baker, P.E. PMP237
ABSTRACT
Six bureaus with dams in the Department of Interior have been working together for the past 4 years to improve their dam safety programs in a project called Reduce Dam Safety Risk (RDSR). The Bureau of Indian Affairs (BIA), Bureau of Reclamation (USBR), Bureau of Land Management (BLM), Fish and Wildlife Service (FWS), National Park Service (NPS) and Office of Surface Mining (OSM) are participating. The goal is to identify and adopt best practices across all bureaus in order to reduce dam safety risks and increase program efficiency. Phase 1 is complete. A total of eight dam safety program areas were addressed: dam examination, scaling of program activities, risk management, Emergency Action Plans (EAP), inundation mapping, dam incident management, dam monitoring quality and terminology/glossary.
This paper describes this RDSR project, the recently completed eight Phase 1 subprojects, and the path forward.
237Mark E. Baker, Program Manager, Dam Safety Office, Bureau of Reclamation, [email protected]
153 NOTES
154 QUALITY AND QUANTITY, IT CAN BE DONE! NC NRCS DAM ASSESSMENTS
Everett L. Litton238 Greg Zamensky, P.E.239 Dennis Hogan, P.E.240
ABSTRACT
The Small Watershed Program authorized the Soil Conservation Service (SCS) as part of the Department of Agriculture to cooperate with states and local agencies to carry out works of improvement such as soil and water conservation, flood prevention, and proper land utilization. The result was one of the largest building periods relating to dams in the history of the United States. Now, over 50 years later, it is the ongoing responsibility of the Natural Resources Conservation Service (NRCS), formerly SCS, to assess the condition of each of these structures and ensure that they continue to meet current safety requirements.
As part of that effort, the North Carolina (NC) NRCS office contracted Black & Veatch in November, 2009 to assess 16 of their flood control dams located throughout the state. The work was to include:
• Review of historical reports and inspections • Site inspections • Existing structure hydraulic performance assessments • Dam breach analysis with inundation mapping • Hazard classification and risk analysis • Overall assessment of existing structures • Alternatives development
The inspection and assessment of these structures was budgeted to be especially efficient. While common wisdom suggests that one must choose either quality or quantity, this particular project defied the odds and provided both through the use of a multi-staged approach to perform the field investigations and the subsequent analysis and reports. This paper provides a case study on the completion of these 16 dam assessments with special attention given to the challenges and efficacy with which they were completed.
238 Project Engineer, Geo-Engineering Department, Black & Veatch Water, Gaithersburg, MD 20879, [email protected] 239 Regional Practice Leader, Geo-Engineering Department – Dams, Levees, and Reservoirs Practice, Black & Veatch Water, Gaithersburg, MD 20879, [email protected] 240 Project Engineer, Geo-Engineering Department – Dams, Levees, and Reservoirs Practice, Black & Veatch Water, Philadelphia, PA 19106, [email protected]
155 NOTES
156 LEVEE SAFETY AND TOLERABLE RISK — IMPLICATIONS FOR SHARED RISK, RESPONSIBILITY, AND ACCOUNTABILITY
Dale F. Munger241 David S. Bowles242 Darryl W. Davis243 Brian K. Harper244 David A. Moser245
ABSTRACT
The US Army Corps of Engineers (USACE) established a levee safety program in November 2007 to assess and manage risks to people, property, and the environment from inundation associated with breach or overtopping of levee systems. USACE intends to use tolerability of risk concepts and tolerable risk guidelines in this program. USACE committed to develop these policies in an open and coordinated manner with its federal, state, local, and tribal stakeholders. In March 2010 USACE began this collaborative approach with stakeholders by hosting an international workshop on tolerable risk.
Levee systems are one part of local, regional and national flood risk management strategies. Levees complement floodplain management activities that govern floodplain use, identify, and reduce vulnerabilities to promote resilient communities. Shared responsibilities for floodplain management at the Federal, state and local levels require collaborative and coordinated decision-making to ensure that flood risks are tolerable.
Levee systems help manage flood risk to existing development and at the same time make floodplains available for more extensive uses such as residential, commercial and industrial development. These activities produce benefits, but increased development places an increased number of people and assets in the floodplain. Consequently, the levee system may lead to an increase in economic risk over time, and may transform economic risk into life-safety risk as the floodplain population increases. Development activities and other floodplain decisions may begin to undermine the risk reduction objectives of the levee system.
This paper provides an overview of the USACE levee safety program, a summary of current USACE levee safety policy concepts and presents and discusses findings of the March 2010 workshop addressing tolerable risk guidelines for levees.
241 U.S. Army Corps of Engineers, Portland, OR, [email protected] 242 Professor of Civil and Environmental Engineering and Director, Institute for Dam Safety Risk Management, Utah State University, Logan, UT. Managing Principal, RAC Engineers & Economists, Providence, UT 243 Senior Advisor, Water Resources Engineering, Institute for Water Resources, U.S. Army Corps of Engineers, Davis, CA 244 Economist, Institute for Water Resources, U.S. Army Corps of Engineers, Galveston, Texas 245 Chief Economist, U.S. Army Corps of Engineers
157 NOTES
158 SEISMIC FRAGILITY OF MÜHLEBERG DAM USING NONLIENAR ANALYSIS WITH LATIN HYPERCUBE SIMULATION
Yusof Ghanaat246 Philip S. Hashimoto247 Olivier Zuchuat248 Robert P. Kennedy249
ABSTRACT
A series of nonlinear seismic evaluations was performed to determine seismic fragility of the Mühleberg Dam as part of the Seismic Probabilistic Risk Analysis (SPRA) of the Mühleberg Nuclear Power Plant (KKM). Probabilistic seismic evaluation was performed by Latin Hypercube Simulation (LHS). Equal probability bins of significant variables were populated with values based on their probability distributions. The variable values were randomly assigned to a total of thirty simulations following the LHS methodology. Nonlinear finite element models of two sections of the dam were developed and analyzed first including all variables, and later including only random variables. These evaluations demonstrated that the seismic capacity of the Mühleberg Dam is controlled by the powerhouse section of the dam and that it is significantly higher than the value obtained from simplified calculations. Failure occurs in the form of sliding through a slip surface that passes through a mudstone layer at the elevation of the bases of the upstream and downstream shear keys.
246 Quest Structures, Inc., 3 Altarinda Road, Orinda, CA 94563, [email protected] 247 Simpson Gumpertz & Heger, Inc., 4000 MacArthur, Newport Beach, CA 92660, [email protected] 248 Formerly with BKW FMB Energie AG, Mühleberg, Switzerland. 249 RPK/Structural Mechanics Consulting, Inc., Escondido, CA.
159 NOTES
160 RESERVOIR SAFETY MANAGEMENT IN HONG KONG
Wan, Chi-fai250 Li, Siu-lung251
ABSTRACT
Hong Kong’s water supply system is the accumulation of over 100 years of work by the Water Supplies Department (WSD) to overcome the difficulties faced by a territory once called a “barren rock”. The potable water supply system now includes seventeen impounding reservoirs, twenty one water treatment works, and a third of Hong Kong’s land mass as gathering ground with an extensive network of catchwater channels on hillsides. This system collects rainwater that meets 20% to 30% of the demand of a population of seven million. The main source of water comes from Dongjiang River in China.
WSD makes reference to the United Kingdom Reservoirs Act (1975) to ensure the safe operation of reservoirs that hold more than 20.3 acre-ft of water above natural ground level. In Hong Kong, there are a total of twenty eight impounding reservoirs (17 nos. for water supply, 10 nos. for irrigation and 1 no. for recreation) and fifty seven large service reservoirs with storage capacity exceeding 20.3 acre-ft operated by WSD. The WSD Reservoir Safety Section is responsible for the routine surveillance, planning and co- ordination of safety upgrades for these reservoirs. Black & Veatch, formerly as Binnie & Partners, engineered a number of major impounding reservoirs in Hong Kong, and is currently appointed by WSD to carry out independent safety inspections for ten impounding reservoirs and twenty five large service reservoirs, and to provide advisory services on matters related to the safety of reservoirs.
This paper introduces the reservoir safety management system in Hong Kong, the types of dam structures forming the impounding reservoirs, and some selected cases of reservoir safety upgrade works in recent years.
250 Technical Director, Regional Practice Leader – Dams, Levees and Reservoirs, Black & Veatch Australia Pty Ltd, Suite 2, 32/F, 100 Miller Street, North Sydney, NSW 2060, Australia, [email protected] 251 Engineer, Reservoir Safety Section, Water Supplies Department of Hong Kong, 45/F, Immigration Tower, 7 Gloucester Road, Wanchai, Hong Kong, [email protected]
161 NOTES
162 LOWER MISSOURI RIVER BASIN DAM AND LEVEE FLOOD FIGHT LESSONS LEARNED
Willem H. A. Helms252 Eugene J. Kneuvean253 Stephen J. Spaulding254 William B. Empson255 Jared D. Mewmaw256 Rexford G. Goodnight257
ABSTRACT
After the Midwestern flood of 1993, the lower Missouri River Basin entered a relatively dry period without major flooding. As a result of that extended period of relatively stable water levels, experience in flood fighting, flood recovery and support to local communities became stagnant. Local knowledge of Federal assistance that can be provided to protect life and property also faded during this period. Numerous changes also occurred in the regulatory, funding and water management environment in which emergency responses are conducted. As a result of flooding in 2007, 2008 and 2010, the U.S. Army Corps of Engineers, Kansas City District developed renewed expertise in moderate flood fight operations on dams and levees and local best practices in emergency operations leadership, organization, equipment, reporting, community outreach and response and risk communication. Equipment used to save an overtopping levee in 2010 is discussed. EOC leadership through the use of Battle Captains to manage the response is presented. Use of helicopters to obtain real time situational awareness to guide flood fight response is presented. An overview of general situations under which Federal assistance can be provided to local districts, sponsors and private individuals to protect life and property is also discussed.
252 U.S. Army Corps of Engineers, Kansas City District, 635 East 12th Street, Kansas City, MO 64106, [email protected]. 253 U.S. Army Corps of Engineers, Kansas City District, 635 East 12th Street, Kansas City, MO 64106, [email protected]. 254 U.S. Army Corps of Engineers, Kansas City District, 635 East 12th Street, Kansas City, MO 64106, [email protected]. 255 U.S. Army Corps of Engineers, Kansas City District, 635 East 12th Street, Kansas City, MO 64106, [email protected]. 256 U.S. Army Corps of Engineers, Kansas City District, 635 East 12th Street, Kansas City, MO 64106, [email protected]. 257 U.S. Army Corps of Engineers, Kansas City District, 635 East 12th Street, Kansas City, MO 64106, [email protected].
163 NOTES
164 HYDROLOGIC AND HYDRAULIC ANALYSES FOR FEMA LEVEE CERTIFICATION IN SAN BERNARDINO COUNTY, CALIFORNIA
Daniela Todesco, P.E.258 Dragoslav Stefanovic, P.E., Ph.D.259 Darren Bertrand260 Mark Seits, P.E.261 Yunjing Zhang, P.E. 262
ABSTRACT
This paper summarizes hydrologic and hydraulic analyses performed for the San Bernardino County Levee Certification Project (Project) and the challenges encountered during the course of the study. The Project included forty-three non-Federal levees on the national levee inventory list, currently mapped by FEMA as Provisionally Accredited Levees (PALs). WEST Consultants performed detailed hydrologic/hydraulic analyses for thirty-five Category 2 levees in order to determine whether they are in compliance with FEMA’s regulatory requirements for certification as identified in Title 44 of the Code of Federal Regulations, Section 65.10 (44 CFR 65.10). In most cases, a complete hydrologic model (HEC-HMS) was built for the contributing watershed to determine/verify the 100-year base flood. Detailed hydraulic models (HEC-RAS) were built for the majority of the levees, some of them with split flow components, lateral spill structures, and unsteady routing. Each levee presented its own challenge in terms of data availability and modeling approach. The results of the hydrologic and hydraulic analyses were eventually used to verify levee freeboard, evaluate sedimentation and potential scour problems at the levee toes, and address any interior flooding issues.
258 Senior Engineer, WEST Consultants, Inc., 503-946-8536, [email protected] 259 Project Manager, WEST Consultants, Inc., 858-487-9378, [email protected] 260 Hydrologist, WEST Consultants, Inc., 858-487-9378,[email protected] 261 Project Manager, HDR, 858-712-8312, [email protected] 262 Senior Engineer, HDR, 858-712-8355, Vicky.Zhang @hdrinc.com
165 NOTES
166 ASSESSMENT OF SITE VARIABILITY AND GEOTECHNICAL LEVEE HAZARD WITH FLOOD FREQUENCY AND REPAIR OPTIONS
Christopher B. Groves263 Hollie L. Ellis264 N. Kyle Tabor265
ABSTRACT
Alluvial site variability and the probability of a geotechnical levee failure are interrelated. The probability of a geotechnical levee failure generally increases with site variability. Highly variable sites are difficult to characterize, and the likelihood of encountering the worst conditions during a subsurface investigation is small. The soil conditions and stratigraphy may be significantly different between borings. Variability of soil parameters have been addressed by estimating the mean and standard deviation of the various parameters and computing the uncertainty in the computed factor of safety based on a mean value analysis. This method estimates the uncertainty of the factor of safety based on the variability of the soil parameters, but does not address variability with regard to site stratigraphy, which has much more uncertainty. Groves et al. (2010) proposed a method to address the probability of a geotechnical levee failure based on the variability of soil stratigraphy. The method assumes that exploratory borings or cone penetration tests determine the subsurface conditions at one location with reasonable accuracy, and that seepage and stability analyses determine the levee factor of safety at that location with reasonable accuracy. The analyses are repeated for many borings or cone penetration tests in a given levee reach. The resulting factor of safety for levee stability is plotted on a cumulative probability curve. The tail of the plotted curve may be extrapolated to estimate the probability of the existence of a location on the levee with a factor of safety lower or higher than those computed at known locations.
The method described above has been extended to show how the risk of a levee failure may be mitigated by a repair to the entire levee system and examine the probability of failure with different flood frequencies. The latter analysis may be helpful in evaluating the probability of a geotechnical failure with a given flood frequency and may provide community officials with an additional flood management tool. In addition, the analysis may assist in evaluating the degree to which a levee repair can reduce the probability of geotechnical failure.
263 Shannon & Wilson, Inc., 2043 Westport Center Drive, St. Louis, MO 63146, PH 314-699-9660, email [email protected] 264 Shannon & Wilson, Inc. 400 N 34th Street, Suite 100, PO Box 300303, Seattle, WA 98103-8600, email [email protected] 265 Shannon & Wilson, Inc., 2043 Westport Center Drive, St. Louis, MO 63146, PH 314-699-9660, email [email protected]
167 NOTES
168 TRANSIENT ANALYSIS — CASE HISTORY OF USE AND IMPACTS
Michael L. Bachand, P.E.266 Michael Stuer267 James S. Drake, P.E.268
ABSTRACT
The city of Lowell, Massachusetts, owns and operates a local protection project (LPP) that was originally designed and constructed by the U.S.Army Corps of Engineers (USACE) in the early 1940s. The original LPP included a combination of 3,500 linear feet of earthen levee, 1,660 feet of I I-wall (concrete faced/steel sheet pile foundation), 3,225 linear feet of seepage collection system, and two flood pumping stations. On January 31, 2007, the city received a letter from USACE requiring that deficiencies observed during a routine levee inspection—including the status of the seepage collection system—be addressed. Due to funding limitations, these deficiencies resulted in the system being listed as inactive and removed from the flood insurance rate maps (FIRMs).
Early in the project, it was determined that the seepage collection system was inoperable and could not be readily repaired. Accordingly, the project focus was directed to an investigation of the function of the seepage collector system with regard to system stability in accordance with current USACE standards. This paper will present the investigations and evaluations performed to levee and floodwall systems, including the geotechnical investigations, engineering analyses—slope stability and seepage—and alternative remedial repair measures. The paper will present a summary of the initial transient analysis in comparison with traditional steady state analyses. The selection of the time-dependent physical properties of the soil layers and geometrical factors will be discussed, including their impact on the resulting factor of safeties. Initially, transient analyses were used to assess the potential impacts on computed factories of safety, which were requiring the city of Lowell to perform remedial repairs to address deficiencies. Ultimately, steady state analysis was used to satisfy USACE requirements due to the limited impact of using the transient analyses compared with the more conservative steady state results.
266Senior Geotechnical Engineer, CDM, 50 Hampshire Street, Cambridge, MA 02139, [email protected] 267 Engineering Manager, Lowell Regional Wastewater Utility, 451 First Street, Lowell, MA, 01850, [email protected] 268 Senior Project Manager, CDM, 670 N. Commercial Street, Suite 201, Manchester, NH, 03101, [email protected]
169 NOTES
170 INTEGRATING DAM INSPECTION SKILLS INTO SAFETY EVALUATIONS FOR LEVEES AND CANALS
Laura LaRiviere, P.E.269 Rebecca Allen, P.E.270
ABSTRACT
Many of us have spent countless hours in the field performing safety inspections of dams of all types and sizes. With the new public and governmental focus on other water resources structures such as levees and canals, how can we, as dam safety professionals, use the skills we have acquired inspecting dams to cross over into safety inspections for levees and canals? While these structures have many similarities in construction, earthen embankments, spillways, waste ways, outlets, their designed purposes can be very different – dams for water storage, canals for water transmission, and levees for periodic water diversion. In addition, dams are typically single site structures while levees and canals can stretch for tens of miles through multiple municipalities, jurisdictions, and land uses. How do we inspect a levee for seepage when it may only encounter water once every 10 to 50 years? How do we deal with local irrigations districts that operate and maintain canals when we are used to working with regulators for dam safety? And why do people think it is okay to landscape canals and levees? This paper highlights the similarities and differences in evaluating these different types of water resource structures and draws on lessons learned from the inspection of levees, “levee certification” studies and canal inspections.
269 Water Resources Engineer, Kleinfelder, 611 Corporate Circle, Suite C, Golden, CO 80401, [email protected] 270 Geotechnical Engineer, Kleinfelder, 611 Corporate Circle, Suite C, Golden, CO 80401, [email protected]
171 NOTES
172 IMPROVING FISH PASSAGE AND PUBLIC SAFETY AT LOW HEAD DAMS
Paul G. Schweiger271 Dr. Luther Aadland272 Don Roarabaugh273 Eric Neast, P.E.274 Chad Hoover275
ABSTRACT
During the 19th and 20th centuries, many low-head dams were constructed on rivers for water supply, ice harvesting, recreation, navigation, power generation (mills), and flow measurement. Due to the knowledge base at the time, little consideration was given to fish passage and public safety when most of these structures were designed and constructed. With significant development occurring in the vicinity of these structures, growing interest in water-based recreation, and the recent movement to restore river and stream environments to a more natural condition, many of these dams are now subject to intense pressures for their removal. When it is necessary to keep the structure in service, the dam owner is often faced with the difficult problems of addressing public safety concerns and providing effective fish passage.
This paper presents the authors’ experience rehabilitating low head dams to improve public safety and provide effective fish passage. Lessons learned from experience with litigation related to drownings at low head dams are discussed with an emphasis on design concepts for modifying low head dams to eliminate the hazardous hydraulic roller. State-of-the-art designs for fish passage facilities for low-head dams will also be presented including Denil, Vertical-Slot, Pool and Weir, Rock Ramp and Nature-Like fishways. The recent rehabilitation of several low-head dams are presented as examples. In addition to providing fish passage, the design of these dams included modern features to eliminate the hazardous hydraulic roller and improve public safety.
271Paul G. Schweiger, P.E., Engineering Manager, Gannett Fleming, Inc., Harrisburg, PA, [email protected] 272 Dr. Luther Aadland, MN DNR, Ecological Stream Habitat Program, Fergus Falls, MN, [email protected] 273 Don Roarabaugh, P.E., Senior Project Engineer, Gannett Fleming, Inc, Harrisburg, PA, [email protected]. 274 Eric Neast, P.E., Senior Project Engineer, Gannett Fleming, Inc., Harrisburg, PA, [email protected] 275 Chad Hoover, CET, Designer, Gannett Fleming, Inc., Harrisburg, PA, [email protected]
173 NOTES
174 PROVIDING FISH PASSAGE AT THE MIDDLE FORK NOOKSACK RIVER DIVERSION DAM
Lawrence M. Magura, P.E., D. WRE276 Clare Fogelsong277
ABSTRACT
Since 2002, the City of Bellingham, WA has been seeking a solution to a dilemma about how to restore fish passage at the site of their diversion dam on the Middle Fork, Nooksack River. The problem was created when the diversion dam was constructed in 1960-61 with no provisions included in it for fish passage. Different options for resolving the fish passage problem have been considered over the intervening years by the City and are discussed in this paper. These options include the addition of a fish ladder to the dam, and a river engineering concept that would have allowed the dam to be partially removed and river water diverted through a new intake structure. These previous concepts failed for various technical feasibility and economic reasons. The City’s search for a feasible solution has now turned to consideration of a siphon-based diversion system coupled with a partial removal of the dam. The current status of the siphon option is discussed.
276 Principal Water Resources Engineer, Black & Veatch Corporation, Lake Oswego, OR 97035, [email protected] 277 Manager, Environmental Resources, Department of Public Works, City of Bellingham, WA 98225 [email protected]
175 NOTES
176 METHODOLOGY FOR HYDROPOWER CERTIFICATION IN ITALY AND SLOVENIA
N. Smolar-Zvanut278 A. Goltara279 G. Conte280
ABSTRACT
The paper describes a technically and economically feasible certification procedure for existing hydro power generation facilities of higher environmental standard, being explicitly coherent with the requirements of the Water Framework Directive (WFD) (EU, 2000) to be implemented in "green labelled" electricity products. The purpose of this European Directive is to establish a framework for the protection of inland surface waters, transitional waters, coastal waters and groundwater which prevents further deterioration and protects and enhances the status of aquatic ecosystems. In order to be certified, a given hydro power plant (HPP) has to commit to carry out appropriate measures in order to mitigate its impacts on specified environmental objectives, in such a way to fulfil predefined environmental objectives and prescriptions. These measures have to be described through a specific management programme, based upon a dedicated environmental study, supported mainly by existing data, but complemented by ad-hoc assessment/monitoring when necessary. The realization of both the environmental study and the management programme must be supported by public consultation; both documents must be approved through an auditing process. In the long run, it is expected that the certification will have a positive impact on hydro power generation in Europe helping to focus the conception of new HPPs towards more sustainable solutions and by simplifying the authorization procedure.
278 Ph.D., Project Manager, Researcher, Institute for Water of the Republic of Slovenia, Hajdrihova 28c, 1000 Ljubljana, Slovenia, [email protected] 279 Director, CIRF - Italian Centre for River Restoration Viale Garibaldi 44/a, 30173 Mestre, Italy, [email protected] 280 Member of Ambiente Italia Technical Managing Board, Ambiente Italia Srl Via Vicenza 5/a, 00186 Rome, Italy, [email protected]
177 NOTES
178 COLLABORATION ON CLIMATE CHANGE ANALYSIS IN THE PACIFIC NORTHWEST
James D. Barton, P.E., D.WRE281
ABSTRACT
Climate change is likely to have a significant effect on the future of water management in the Pacific Northwest. Because many rivers in this region such as the Columbia River are operated as a coordinated system and involve many different owners and operators, regional collaboration among the various entities is extremely important. This is particularly true on issues like climate change, where the effects may vary considerably in different parts of the region.
In collaboration with the Bureau of Reclamation, Bonneville Power Administration, and other entities in the region, the U.S. Army Corps of Engineers Northwestern Division has efforts underway to analyze the effects of climate change on water management activities in the Pacific Northwest using a regional approach. One of the major goals of this effort is to develop a common set of data, models, and tools that can be used by entities throughout the region to analyze climate change. If it is successful, this effort will reduce the possibility for duplication, overlap, and conflicting results on climate change activities undertaken by the various entities, while at the same time improving regional collaboration and coordination.
This paper will describe a regional collaborative effort on climate change analysis in the Pacific Northwest that was initiated in 2008 and will be completed in 2011. It will provide some important lessons learned and other information for other organizations involved in water management who are considering similar efforts.
281 Chief of Columbia Basin Water Management Division, U.S. Army Corps of Engineers, Northwestern Division, Portland, OR 97208, [email protected]
179 NOTES
180 DEFORMATIONS OF A ZONED ROCKFILL DAM FROM A LIQUEFIABLE THIN FOUNDATION LAYER SUBJECTED TO EARTHQUAKE SHAKING
Mahmood Seid-Karbasi282 Upul Atukorala283
ABSTRACT
Seismic safety of embankment dams is affected by dam crest displacements and the intactness of the seepage control system. There are a number of simplified pseudo-static methods of analyses along with data from past earthquakes that can be utilized to assess the seismic performance of dams when seismic-induced softening and/or liquefaction of soils is not anticipated. However, when liquefiable materials are present in the dam body or its foundation, more rigorous procedures should be employed. This paper describes the results of dynamic analyses carried out for a 85-m high zoned rockfill dam retaining tailings founded on liquefiable alluvial soils underlain by stiff residual soils and bedrock. The assessment was carried out for dam closure conditions and MDE ground motions (i.e. PGA = 0.33g) using a coupled stress-flow method of analysis. The constitutive model UBCSAND was used to model the liquefiable soils and UBCHYST was used to model the nonlinear behaviour of non-liquefiable materials within the dam-foundation system. The results show that in this case the presence of a thin liquefied alluvium leads to a rigid-block type deformation of the dam with insignificant loss of freeboard. This article exemplifies the necessity of more advanced analysis for optimum design and assessment of seismic performance of dams when materials that are prone to liquefaction are involved.
282Geotechnical Engineer, Golder Associates Ltd, 500 - 4260 Still Creek Drive, Burnaby, BC, Canada, [email protected] 283Principal Geotechnical Engineer, Golder Associates Ltd, 500 - 4260 Still Creek Drive, Burnaby, BC, Canada, [email protected]
181 NOTES
182 SEVERAL OBSERVATIONS ON ADVANCED ANALYSES WITH LIQUEFIABLE MATERIALS
Michael H. Beaty284 Vlad G. Perlea285
ABSTRACT
The expected behavior of an embankment dam under earthquake loading is best related to estimates of seismic deformation. Currently, predictions of the magnitude and pattern of seismic deformation are used for both the evaluation of dam safety and the validation of remediation designs for seismically-deficient embankment dams. The US Army Corps of Engineers uses a phased approach for evaluating seismic safety that begins with simple evaluation tools and proceeds, when necessary, to sophisticated analyses. Advanced analyses are generally required for dams of high risk, with significant seismic loads, founded on problem soil, or when simplified evaluations have not resolved seismic concerns. These advanced tools often use non-linear and plasticity-based constitutive models in a two-dimensional finite difference or finite element analysis. One of the major problems with applying these tools to dams with liquefiable soils is the selection of a reliable constitutive model for these problem soils. This paper discusses some of the requirements of such models and the potential effects of modeling assumptions on the predicted seismic deformation. Comparative analyses are performed and the results obtained with advanced models are compared with those from simpler models. The importance of various features on the seismic deformation results is emphasized.
284 Principal Engineer, Beaty Engineering LLC, Beaverton, Oregon, 97007 [email protected] 285 Civil Engineer, US Army Corps of Engineers, Sacramento District, Sacramento, California, 95814 [email protected]
183 NOTES
184 HEBGEN DAM ─ A HISTORY OF EARTHQUAKE HAZARDS AND ANALYSES
Steve Benson, P.E.286 Tom O’Brien, P.E.287 Bonnie Witek, L.G., L.E.G.288 Ethan Dawson, Ph.D.289
ABSTRACT
This paper presents a retrospective of the 1959 Mw 7.3 earthquake at Hebgen Dam and an overview of subsequent analyses performed for evaluating the safety of the dam under seismic loading. The paper describes the effects of the 1959 earthquake on the dam and appurtenant structures and subsequent repairs followed by a summary of recently completed geotechnical investigations and seismic analyses of the dam.
URS performed a sensitivity analysis of seismic deformation of the dam in 2009 using the simplified method of Bray and Travasarou (2007). The purpose of this analysis was to make a preliminary determination of the ranges of expected slope and crest deformations under seismic loading for use in a supplemental Potential Failure Mode Analysis (PFMA). Based on the results of this study and the PFMA, it was decided that further investigation and analysis work was justified to evaluate the embankment under seismic loading conditions.
URS subsequently analyzed the embankment dam under seismic loading using time histories considered representative of the Maximum Credible Earthquake occurring on the Hebgen-Red Canyon fault and the computer program FLAC (Fast Lagrangian Analysis of Continua). Engineering evaluation of the results concluded that although the dam would be damaged from deformation of the crest, the dam would be stable for post seismic conditions. Deformation would not cause failure of the dam and uncontrolled release of the reservoir.
286 Manager of Geotechnical Engineering, URS Energy and Construction, Bellevue, Washington, [email protected] 287 Senior Geotechnical Engineer, URS Energy and Construction, Bellevue, Washington, [email protected] 288 Senior Engineering Geologist, URS Energy and Construction, Bellevue, Washington, [email protected] 289 Senior Geotechnical Engineer, URS Infrastructure and Environment, Los Angeles, California, [email protected]
185 NOTES
186 SEISMIC ANALYSES AND POTENTIAL FAILURE MODES OF THE INTAKE TOWER AND BOREL CONDUIT AT LAKE ISABELLA AUXILIARY DAM
Said Salah-Mars290 Mourad Attalla291 Erik Newman292 Chung Wong293 David Serafini294 Michael Ma295 Yusof Ghanaat296 Faiz Makdisi297 Keith Ferguson298
ABSTRACT
Lake Isabella is a 568,000 AF reservoir in Kern County, California impounded by two earth-fill embankment dams: a 185-foot high main dam and a 100-foot high auxiliary dam. Each dam includes an embedded intake tower to control flow releases. Recent investigations of the Kern Canyon fault, which traverses beneath the auxiliary dam at its right abutment, indicate that the fault is active and has ruptured at least once within the last 3500 years.
The Lake Isabella reservoir is classified as one of the highest risk projects in the Corps’ inventory under the Dam Safety Action Classification (DSAC) system outlined in Draft ER1110-2-1156. The seismic analyses of the auxiliary dam modeled the foundation, embankments, and tower and conduit to properly represent the soil-structure-interaction effects. The results of the analyses show that under moderate to high levels of shaking, the towers’ moment and shear demands would substantially exceed their capacity, resulting in a high potential for development of gross failures of these structures. Further, the excessive embankment deformation of the auxiliary dam adjacent to the tower and conduit would result in shear and tensile failures of the conduit joints. These types of failures could result in the development of piping failure modes leading to an uncontrolled release of the reservoir threatening the downstream population including the Lake Isabella and Bakersfield, CA.
290 Vice President, URS Corporation, 1333 Broadway Ave., Suite 800, Oakland CA 94612, Said_Salah- [email protected] 291 Project Manager, URS Corporation 1333 Broadway Ave., Oakland CA 94612, [email protected] 292 Staff Engineer, URS Corporation 1333 Broadway Ave., Oakland CA 94612, [email protected] 293 Structural Design Section, USACE Sacramento District, 1325 J Street, Sacramento, CA 95814, [email protected] 294 Dam Safety Section, USACE Sacramento District, 1325 J Street, Sacramento, CA 95814, [email protected] 295 Structural Design Section, USACE Sacramento District, 1325 J Street, Sacramento, CA 95814, [email protected] 296 President Quest Structures, Inc., 3 Altarinda Rd., Suite 203, Orinda, CA 94563, [email protected] 297 Vice President, AMEC/Geomatrix, Inc., 2101 Webster Street , 12th Floor, Oakland , CA 94612, [email protected] 298 Vice President, HDR Inc., 303 East 17th Ave, Suite 700, Denver, CO 80203, [email protected]
187 NOTES
188 NEAR FAILURE OF THE ALL AMERICAN CANAL IN SOUTHERN CALIFORNIA DUE TO A 7.2 MAGNITUDE EARTHQUAKE IN APRIL, 2010
Bob Dewey299 Dave Palumbo300
ABSTRACT
On Easter Sunday, 2010, a 7.2 magnitude earthquake struck northern Mexico near Mexicali. The All-American Canal, which diverts Colorado River water from the Imperial Reservoir and delivers irrigation water throughout the Imperial Valley, was heavily damaged. The canal parallels the California/Mexico border and the siphon carries water across the New River in southern California only 22 miles from the earthquake epicenter. The earthquake damaged the concrete canal lining, separated vertical and horizontal joints at the inlet of the siphon and wasteway, liquefied materials in the New River channel, and opened up wide cracks and fissures in the 40-foot-high embankment fill and riverbank supporting the canal, gate structure, siphon and wasteway. Concentrated seepage was observed exiting near the toe of the embankment fill between the siphon and the wasteway. Many aftershocks occurred, but the seepage remained steady for another week after the April 4th main shock. Eight days after the initial earthquake, the quantity of seepage suddenly increased approximately ten fold. That evening a significant aftershock of 4.8 magnitude occurred, and the seepage increased even more causing internal erosion of embankment materials to begin in earnest. This paper discusses the incident, what mitigation actions were taken that night to save the siphon structure, follow-up investigations and continuing engineering studies.
299Technical Specialist, U.S. Bureau of Reclamation, Geotechnical Engineering Services Division Technical Service Center Denver, Colorado, email: [email protected] 300Regional Engineer, U.S. Bureau of Reclamation, Engineering Services Office, Lower Colorado Region, Boulder City, Nevada, email: [email protected]
189 NOTES
190 EARTHQUAKE RESPONSE OF ROCKFILL DAM WITH ASYMMETRIC PLAN GEOMETRY OF UPSTREAM AND DOWNSTREAM SLOPE WITH RESPECT TO DAM AXIS
Ik-Soo, Ha301
ABSTRACT
Two-dimensional dynamic analysis for the maximum section of a dam cannot consider the canyon effect, because it is carried out in the plane strain condition. Also, if the plan geometry of upstream and downstream slope is not symmetrical with respect to the dam axis, the results of 2-D analyses cannot accurately represent dynamic response of the dam to earthquake. In this study, three-dimensional dynamic analyses for Miryang multi- purpose dam (concrete-faced rockfill type) in South Korea, with asymmetric plan geometry of upstream and downstream slope with respect to the dam axis, were carried out and the response of the dam was analyzed. The results of 3-D dynamic analyses were compared with those of 2-D plane strain dynamic analyses. It was found that the maximum settlement did not appear at the maximum cross-section and the magnitude of maximum settlement obtained by 3-D analysis was different from that by 2-D analysis for the maximum cross-section. Furthermore, it was found that the characteristics of acceleration amplification obtained by 3-D analysis were different from those by 2-D analysis. This study presents an insight in the earthquake response behaviors of a rockfill dam with the asymmetric plan geometry of upstream and downstream slope with respect to the dam axis. It can also be used as fundamental data for seismic stability and design for rockfill dams with asymmetric plan geometry of upstream and downstream slope.
301 Principal Researcher, Dam Safety Research Center, Korea Water Resources Corporation, Daejeon, Republic of Korea, [email protected]
191 NOTES
192 BEHAVIOR CHARACTERISTICS OF COMPOSITE DAM USING CENTRIFUGE
Jeong-Yeul, Lim302 Ik-Soo, Ha303
ABSTRACT
Existing dams are an important part of the safety problems, because climate change is related to increased earthquakes magnitude and the PMP and PMF.
Dam safety problems are no exceptions. Especially, the composite dam which is constructed other dam types has characteristic of different behavior during the earthquake. In the evaluation of the seismic stability of a composite dam, besides others, the main problem is the dynamic interaction between concrete gravity dam and soil embankment. In this study is analyzed dynamic behavior characteristic of composite dam, which is composed of concrete gravity and embankment section, using centrifuge (including shaking table test). In this test, prototype model is 1/40 scale model of the existing composite dam and the test condition is centrifugal a 40g. In addition, the Hachinohe (long-period) and Ofunato (short-period) waves are applied.
The characteristics of dynamic behavior are compared with those obtained by the centrifuge test which is carried out in the earthquake wave of Korea earthquake conditions. Furthermore, the results obtained in this the centrifuge test are compared with the 3D numerical analysis of the composite dam.
302 Principal Researcher, Dam Safety Research Center, Korea Water Resources Corporation, Daejeon, Republic of Korea, [email protected] 303 Principal Researcher, Dam Safety Research Center, Korea Water Resources Corporation, Daejeon, Republic of Korea, [email protected]
193 NOTES
194 SAN ROQUE MULTIPURPOSE PROJECT — PERFORMANCE MONITORING ASSESSMENT
Michael Pavone, P.E.304 Joseph Ehasz, P.E.305 Stephen Benson, PE.306 Bonnie Witek, L.G., L.E.G.307
ABSTRACT
The San Roque Multipurpose Project (SRMP) is a major hydroelectric and flood-control project in Asia. The 200-meter-high, central clay core, rock-fill dam is the 12th highest dam of its kind in the world. It is located on the Agno River in the Philippines and impounds a reservoir with a surface area of about 12.8 square kilometers that provides flood attenuation benefits downstream of the dam. The SRMP has an installed rated capacity of 411 megawatts.
URS was awarded two contracts totaling $705 million for the engineer-procure-construct (EPC) work by San Roque Power Corporation. Performance monitoring of the project began prior to first filling of the reservoir and continues on a regular schedule.
Key design requirements included stringent leakage criteria and reliability in this seismically active region. The performance monitoring program for San Roque Dam includes instrumentation monitoring and routine visual inspections. The program is intended to provide verification of design parameters, analyze adverse effects, verify performance, and identify any potential safety concerns. Instrumentation includes: 1) piezometers, 2) movement survey monuments, 3) seepage flow measurement stations, 4) rainfall gauge, and 5) turbidity meters.
This paper presents the evaluation of monitoring program data with regards to pore water pressures, seepage, and deformation considering the designer’s (URS’) prediction of performance. Performance prediction is generally tied to the appropriate factors of safety which, along with other design parameters such as calculated deformations, seepage flows and piezometric pressures, determine the desired threshold limits for the design conditions.
304 Manager of Engineering, URS Energy and Construction, Bellevue, Washington, [email protected] 305 Vice President, URS Energy and Construction, Bellevue, Washington, [email protected] 306 Manager of Geotechnical Engineering, URS Energy and Construction, Bellevue, Washington, [email protected] 307 Senior Engineering Geologist, URS Energy and Construction, Bellevue, Washington, [email protected]
195 NOTES
196 AUTOMATION OF THE LONG-TERM TECHNICAL MONITORING OF THE OŽBALT CONCRETE DAM
Pavel Žvanut308
ABSTRACT
The Ožbalt concrete gravity dam, part of the corresponding hydro-power plant (HPP) on the Drava River, in Slovenia, was built in 1960, and renovated in 2003. Its structural height is 33 m, and the dam crest has a length of 167 m. Long-term monitoring of the Ožbalt dam spans over 40 years. Using the new automatic monitoring system, since 2006, it has been possible to perform comprehensive analyses of all the assembled data, and, as well as this, the system is reliable, user-friendly and open for potential upgrading and extension of the automation to additional parameters. Thanks to automatic measurements of various important parameters within the scope of Ožbalt dam long-term monitoring program, continuous monitoring of these parameters can be performed, which means that rapid decisions can be made in the case if and when something begins to go wrong, i.e. when measured values exceed the limit values. The aim of future long-term monitoring of Ožbalt dam is to obtain as large as possible a data-base about the results of the measurements, which will be useful for diagnosis of the condition of the Ožbalt dam and its surroundings.
308 Researcher, ZAG - Slovenian National Building and Civil Engineering Institute, Ljubljana, Slovenia, [email protected]
197 NOTES
198 WEB-BASED REAL-TIME MONITORING AT PERRIS DAM USING IN-PLACE INCLINOMETERS AND PIEZOMETERS WITH AN AUTOMATIC NOTIFICATION SYSTEM
John Lemke, PE, GE309 Mike Driller, PE, GE310 Dan Wilson, PhD311
ABSTRACT
A real-time monitoring system was used to monitor subsurface movements and groundwater levels at Perris Dam during the construction of a liquefaction remediation test section. The test section considered herein included dewatering, driving sheet piles, excavation and replacement of soil, and deep soil cement mixing. The California Department of Water Resources (DWR) implemented a geotechnical instrumentation program to automatically and continuously monitor changes in subsurface movements and groundwater levels using in-place inclinometers and electronic piezometers, respectively. Each remote station at the project site automatically transmitted readings to a server at selected time intervals using wireless Internet modems. Plots of in-place inclinometer displacement profiles and water elevation were monitored by DWR project team members via a secure web page during and after construction. Water levels and displacement profiles were calculated and compared automatically, in real-time, to pre- established threshold levels. The server computer was programmed to initiate phone calls to a list of designated project members whenever threshold levels were exceeded. Each automated message included the project name, remote station number, and relevant reading from the in-place inclinometer or piezometer instrumentation. The real-time monitoring system used at Perris Dam provided continuous feedback during remediation construction work and provided a cost effective way to achieve continuous field observation with an automatic notification system. This paper will discuss the specification, set up, and performance of the geotechnical monitoring system during the test section monitoring.
309 Geodaq, Inc., 3385 Lanatt Street, Suite A, Sacramento, CA 95819, (916) 930-9800, [email protected] 310 Department of Water Resources, 1416 9th Street, Room 538, One Shields Ave., Sacramento, CA 95814, (916) 698-8724, [email protected] 311 Center for Geotechnical Modeling, University of California at Davis, Davis, CA 95616, (530) 754-9761, [email protected]
199 NOTES
200 ASSESSMENT METHOD FOR ROUTINE DAM SAFETY MONITORING PROGRAMS
Jay N. Stateler312
ABSTRACT
The U.S. Department of Interior (DOI) recently tasked a team, involving representatives of all the DOI agencies that have dams, to look at “quality control/quality assurance” issues with respect to routine dam safety monitoring. The team developed a Monitoring Program Assessment Form (MPAF) that breaks the routine dam safety monitoring process down into eight “elements,” with all but two of these elements further broken down into “sub-elements.” Breaking the process down in this way allows a close and careful evaluation of each of the “building blocks” of an effective routine dam safety monitoring program. One area of the MPAF is used to document the approach currently being used by the organization with respect to each element/sub-element so as to ensure that it is being appropriately carried out/satisfied. Another area assesses whether the current approach is apparently in need of significant improvement, and another area is used to generate possible solutions to the apparent problems that are identified. To aid assessments performed within DOI, the Team developed DOI Standards with respect to all the elements/sub-elements. Also, weighting factors were developed for each of the elements/sub-elements so that a quantitative rating between 0 and 100 could be developed using the MPAF, if desired. While rather simple in concept, initial use of the MPAF in the DOI agencies has proven it to be a powerful tool for: (1) pinpointing problem areas in current routine dam safety monitoring work and approaches, and (2) identifying possible solutions that are focused on the identified problem areas.
312 Civil Engineer, Bureau of Reclamation, Denver, CO, [email protected]
201 NOTES
202 NONDESTRUCTIVE EVALUATION OF SEEPAGE IN AN EARTHEN DAM
John Stoessel, P.E.313 Matthew Pruchnik, P.E.314 Paul Rollins315
ABSTRACT
Vermilion Valley Dam is a large earthfill dam located in the Sierra Nevada mountains east of Fresno, California. Completed in 1954, the 165-foot high, 4,234-foot long dam, situated in a glacially carved valley containing glacial till and moraine deposits has had a history of seepage issues. During the summer of 2007, seepage was observed at the toe of the dam during high reservoir conditions. The reservoir was drawn down and an engineered subsurface filter system was constructed to intercept the predicted seepage. After several years of draught, 2010 proved to be a wet year and the reservoir levels were back to where they had been in 2007. Seepage was observed about 30 feet downstream of where the 2007 seepage was seen. After constructing a sandbag chimney to confine water, provide some head to resist soil movement, and allow quantitative monitoring of the seepage levels, Willowstick was contracted to perform a geophysical investigation of seepage through the dam. The results of their investigation are presented in this paper, as well as proposed upgrades to the filter system at Vermilion Valley Dam.
313 Senior Engineer, Southern California Edison, 300 N. Lone Hill Ave., San Dimas, CA 91773. Phone 909 394-8916, email [email protected] 314 Engineer, Southern California Edison, 300 N. Lone Hill Ave., San Dimas, CA 91773. Phone 909 394- 8882 email [email protected] 315 Vice President of Business Development. Willowstick, 1184 Election Rd., Suite 100, Draper, UT 84020. Phone 801 984-9850, email [email protected].
203 NOTES
204 FIBER OPTICS BASED MONITORING OF LEVEES AND EMBANKMENT DAMS
Jean-Robert Courivaud316 Patrick Pinettes317 Cyril Guidoux318 Jean-Jacques Fry319 Yves-Laurent Beck320
ABSTRACT
Distributed temperature and strain measurements by fiber optics are presented as a new powerful technology for leakage monitoring in embankment dams and levees. After having shown the principles of this technology and its related analysis methods for processing raw temperature data, its validation on several large scale field tests and real sites is demonstrated. The industrial deployment of this technology on two projects of channel rehabilitation is then illustrated. The first site is a 5.2 km long intake channel on the Durance river, in the South-East of France. The upstream watertight bituminous concrete face of this 45 year-old channel has suffered from damages that induce leakages that may evolve in dangerous internal erosion processes. The rehabilitation of the monitoring system will include a fiber optics installation designed to detect on the one hand leakages through the new upstream watertight bituminous concrete face of the structure, on the other hand strains at the interface between the apron and the foundation. The second site is a 15 km long intake channel on the Rhône river, near the city of Lyon. This 110 year-old silt levee has been suffering for decades from contact erosion and suffusion. As the existing conventional monitoring system, based on piezometers and leakage discharge measurements has not been able to detect the pathology in action, it has been decided to design a surveillance including fiber optics installed in the drainage channel as well as at the toe of the downstream face of the levee.
316 Hydraulic and Geotechnical Engineer, Hydro-Engineering Center, EDF, Savoie Technolac, 73373 Le Bourget du Lac, France, [email protected] 317 President, geophyConsult SAS, Savoie Technolac, 12 allée du Lac de Garde, B.P. 231, 73374 Le Bourget du Lac, France, [email protected] 318 Engineer, geophyConsult SAS, Savoie Technolac, 12, allée du Lac de Garde, B.P. 231, 73374 Le Bourget du Lac, France, [email protected] 319 Dam expert, Hydro-Engineering Center, EDF, Savoie Technolac, 73373 Le Bourget du Lac, France, [email protected] 320 Engineer, EDF – DTG, 21, avenue de l’Europe, B.P. 41, Grenoble cedex, France, yves- [email protected]
205 NOTES
206 PARADIGM SHIFTS IN MONITORING LEVEES AND EARTHEN DAMS: DISTRIBUTED FIBER OPTIC MONITORING SYSTEMS
Daniele Inaudi321 Joseph Church322
ABSTRACT
Earthen embankments including levees, tailings dams, and earthen dams present many challenging problems for Civil Engineers, particularly in verification of their structural integrity and capacity, operation and maintenance (O&M), inspection, and safety. The sheer size and scale, age, and uncertainty of materials in these sometimes mammoth structures, all combine to present a difficult array of parameters for the levee professional to navigate when analyzing a new or existing levee or dam.
To make things more difficult, there are an ever growing number of assets and lives these structures protect downstream or in the “flood plain,” and more and more emphasis is being placed on the vulnerability of these structures. Also, in the wake of flood disasters associated with Hurricane Katrina and others, a complex regulatory environment has emerged; requiring engineers to certify structural and geotechnical fortitude, and levee and dam asset owners and engineers are exposed to more liability than ever.
Recent advances in instrumentation technologies and applications are providing new ways the Civil Engineer examines these structures, and present engineers with a set of monitoring tools never thought possible. Distributed fiber optic technologies create sensors that are of scale and size to finally match the dam or levee, and present an interesting, reliable, cost effective way of monitoring these structures.
321 Dr. Danieli Inaudi, Smartec SA, Lugano, Switzerland, [email protected]. 322 Joseph Church, PE, Roctest, Inc., Sullivans Island, SC, 29482 USA, [email protected].
207 NOTES
208 ROGUE PIEZOMETERS
Douglas A. Crum323
ABSTRACT
Large dams are typically instrumented with piezometers. Federal dams often have tens or hundreds of piezometers. Piezometers are installed and monitored for multiple reasons; including preconstruction site conditions, construction performance, first filling performance, and long term monitoring. In the author’s experience, most piezometers have been installed for the purposes of construction performance or first filling. Because piezometer installation is expensive, piezometers installed for any purpose are usually adopted and maintained for long term monitoring. Instrumentation advocates recommend that all devices have a clear purpose and performance predictions before installation, but this goal is implausible with inherited instrumentation. Robust programs for reading, reducing and plotting data from these devices naturally focus evaluation efforts on screening for deviations from normal. Specific issues or continuing evaluations lead to more detailed interpretation and ad hoc evaluation. Standard processes for interpretation and evaluation of instrumentation is a capricious subject since there is a myriad of possible trends and behaviors that can be derived from such instrumentation. Yet, there are some commonalities for instrumented dams that can be defined. Further complicating evaluations, piezometers may not even be responding accurately. With the increasing age of federal and private sector dams and existing instrumentation, even long lasting instruments (such as standpipe piezometers) have reliability problems. With large numbers of instruments that are inherited by new generations of engineers tasked with monitoring dams, a better defined standard of practice is needed. This paper provides suggestions for strengthening routine evaluations, including definition of instrument purposes, threshold values, response to pool level correlations, response testing, and abandonment/replacement issues.
323 Dam Safety Program Manager, Corps of Engineers, Kansas City, MO 64106, [email protected]
209 NOTES
210 PERFORMANCE OF DAMS AND SPILLWAYS — 2009 GEORGIA FLOOD
Randall P. Bass, P.E.324 James R. Crowder, P.E.325 Joseph S. Monroe, P.E.326
ABSTRACT
During the latter part of September 2009, the Atlanta metro area received several days of steady rain that cumulated with a high intensity event in the early morning hours of 21st. Counties west of the metropolitan Atlanta area received in excess of 22 inches of rain in a 24 hour period. Other regions in the greater metropolitan area of Atlanta received between 7 and 15 inches over the same 24 hour period. As a result of the intense rainfall, record flooding ensued with some stream gages recording flow rates greater than five times the previously documented record flows.
As a result of the intense rainfall and associated flooding, the auxiliary spillway systems for numerous dams activated to discharge the storm water runoff from the reservoirs. In addition, several small unregulated low-hazard dams overtopped and breached. Thanks in large part to an active Safe Dams Program, no failures of high-hazard dams were reported; however, damage did occur to numerous spillway systems as result of the subject storm.
This paper will discuss the September 2009 storm and place the recorded rainfall into historical perspective as it is relate to past extreme events and hydrologic/hydraulic design requirements as required by both State and Federal agencies; review the design and performance of several Natural Resources Conservation Service dams experienced rainfall amounts in excess of the 100-year event; discuss the performance of several dams that overtopped; and present the performance of numerous earth and rock cut auxiliary spillway channels. In addition, the paper will discuss the actions that have been or will be implemented to repair or improve, if necessary, the damaged structures.
324 Principal, Schnabel Engineering, 6445 Shiloh Road, Suite A, Alpharetta, Georgia 30005, [email protected] 325 Senior Associate, Schnabel Engineering, 6445 Shiloh Road, Suite A, Alpharetta, Georgia 30005, [email protected] 326 Senior Associate, Schnabel Engineering, 6445 Shiloh Road, Suite A, Alpharetta, Georgia 30005, [email protected]
211 NOTES
212 USING MULTIPLE METHODS TO IMPROVE HYDROLOGIC HAZARD ESTIMATES FOR DAM SAFETY
Frank Dworak327
ABSTRACT
The Bureau of Reclamation uses hydrologic loadings in the form of hydrologic hazard curves for dam safety risk analysis. These hydrologic hazard curves typically consist of peak flow frequency, volume frequency, and flood hydrographs for a full range of Annual Exceedance Probabilities (AEPs). Multiple methods and paleoflood data are used to estimate flood frequency based on the level of hydrologic information required, the availability of stream gage and rainfall data, location of the dam, and previous studies performed for the dam. These methods include deterministic and stochastic modeling approaches, some including rainfall-runoff modeling, with each having a unique combination of input data. In applying these methods, Reclamation assumes some degree of total (prediction) error dependent on data inputs and model algorithms. Model prediction error can usually be reduced through improved quality and quantity of the input data, and is commonly characterized using confidence or prediction intervals. Reclamation attempts to put a bound on prediction error by increasing available input data and using multiple independent methods (models) for each hydrologic hazard study. Methods used are dependent on the level of the study required for the project.
Using multiple methods for each study allows the hydraulic engineer to explore a larger range of possible model error, and provide ranges of predictions that may include data uncertainty. Putting bounds on these errors and uncertainties can allow for a better estimate of the true (unknown) flood frequency for a drainage basin. Reclamation uses paleoflood data as one way to refine the estimate and extrapolate flood frequency curves beyond the date of recorded data. Reclamation uses the principle that geomorphologic evidence of historic extreme floods and non-exceedance bounds can be used directly in flood frequency analysis. These data provide points in which to base model extrapolations. Therefore, the final flood frequency product results in a range of flood frequencies that have been created with more input data, a bound on possible model prediction error, and a paleoflood point of extrapolation beyond recorded data resulting in a higher confidence in the hydrologic hazard and a better estimate of the true flood frequency for a drainage basin.
327 Hydraulic Engineer, Flood Hydrology and Emergency Management Group, 86-68250, Bureau of Reclamation, Denver, CO 80225, [email protected]
213 NOTES
214 DEVELOPMENT OF A RESTRICTED RESERVOIR OPERATING PLAN AT WEST POINT DAM, GEORGIA
Kevin Fagot, P.E.328 Jamie M. Bartel, P.G.329 Andy Ashley, P.E.330 Michael Schmidt, P.E. BCEE331
ABSTRACT
Currently, the spillway gates at West Point Dam, a U.S. Army Corps of Engineers project operated by the Mobile District, on the Chattahoochee River in Georgia have trunnion rod issues and need to be repaired. These structural issues with the spillway gates may cause two of the six gates to be taken off line. If this occurs, stoplogs would be placed in front of the two non-operating gates. The top of the stoplogs is at elevation 638.0 feet. This would become the new limiting elevation, and the reservoir would need to be kept at or below this elevation using only four of the six spillway gates. Because of this, a restricted reservoir operating plan (RROP) needed to be developed for West Point Dam. For this analysis, several historical events ranging from 1919 to 2009 along with the Standard Project Flood (SPF) and Spillway Design Flood (SDF) were analyzed. The effect of dropping the top of the conservation pool to a lower elevation as well as altering the induced surcharge operation for a more aggressive release schedule was studied. This paper covers the development of the restricted reservoir operating plan as well as explaining how the Hydrologic Engineering Center (HEC) program, Res-Sim, was used to perform this analysis.
328 Project Engineer, WEST Consultants, Bellevue, WA, [email protected] 329 Task Order Manager, Geologist, CDM Federal Programs, Baton Rouge, LA, [email protected] 330 Chief, Water Management Section, U.S. Army Corps of Engineers, Mobile District, [email protected] 4Project Manager, Vice President, CDM Jacksonville, FL, [email protected]
215 NOTES
216 EVOLVING DESIGN APPROACHES AND CONSIDERATIONS FOR LABYRINTH SPILLWAYS
Greg Paxson, P.E.332 Dave Campbell, P.E.333 Joe Monroe, P.E.334
ABSTRACT
Modern labyrinth spillway design criteria began with the work of Taylor (1968), followed by Hay and Taylor (1970). Various works by the Bureau of Reclamation and ultimately, the publication Design and Construction of Labyrinth Spillways (Lux and Hinchliff, 1985) provided dam engineers with a design method for this structural spillway alternative.
Tullis et al. (1995) and other researchers have extended the available knowledge base and practitioners have designed hundreds of labyrinth spillways. In 2003, Falvey published Hydraulic Design of Labyrinth Spillways, which addressed past research and added some new interpretations. This publication, combined with the need to upgrade existing dams to meet new spillway design flood criteria, has brought about considerable expansion in the use of labyrinth spillways.
Labyrinth spillway design is now a standard tool in the dam engineer’s toolbox. However, due to the hydraulic complexity of these folded weirs, the range of geometries, headwater, tailwater, approach conditions, and other performance factors, our knowledge base is still limited. Ongoing research is answering some of these questions and additional research is needed to address others. This paper provides an overview of research developments and applications of labyrinth hydraulic designs as a backdrop for discussion of expected additions to this knowledge base and the need for additional research to more fully understand labyrinth performance. Specific items of discussion include energy dissipation, non-standard geometries, and staged labyrinth weirs.
The discussion also addresses practical design considerations. While "hydraulically" efficient designs are desirable, hydraulic optimization is not always practical due to increased construction costs and/or an inability to economically construct a hydraulically optimized weir layout into site topographic, geologic and facility constraints. As designers, we acknowledge and accept reduced hydraulic efficiency when it is associated with enhanced overall project effectiveness. Examples are presented for site conditions where a compromise in hydraulic efficiency results in reduced construction cost.
332 Principal, Schnabel Engineering, West Chester, Pennsylvania, [email protected] 333 Senior Consultant, Schnabel Engineering, West Chester, Pennsylvania, [email protected] 334 Senior Associate, Schnabel Engineering, Alpharetta, Georgia, [email protected]
217 NOTES
218 THE DESIGN AND ANALYSIS OF LABYRINTH WEIRS
B.M. Crookston335 B.P. Tullis336
ABSTRACT
The experimental results of 32 physical models were used to develop a hydraulic design and analysis method for labyrinth weirs. Discharge coefficient data for quarter-round and half-round labyrinth weirs are presented for 6° ≤ sidewall angles ≤ 35°. The influence of cycle geometry, cycle configuration, spillway orientation and placement, nappe flow regimes, artificial aeration (vents, nappe breakers), and nappe stability on hydraulic performance are discussed. The validity of this method is presented by juxtaposing discharge coefficient data from this study and previously published labyrinth weir studies.
335Postdoctoral Researcher, Utah Water Research Laboratory, Utah State Univ., 8200 Old Main Hill, Logan, Utah 84321, Phone: (435) 797-3171, Email: [email protected] 336Assoc. Prof., Utah Water Research Laboratory, Utah State Univ., 8200 Old Main Hill, Logan, Utah 84321, Phone: (435) 797-3194, Email: [email protected]
219 NOTES
220 UPGRADING LAKE HOLIDAY SPILLWAY USING A LABYRINTH WEIR
John Ackers337 Felicity Bennett338 Greg Zamensky339
ABSTRACT
A new labyrinth weir and spillway are to be constructed at Lake Holiday Dam to satisfy the recently updated dam safety regulations for the State of Virginia. Subject to compliance with a number of conditions, this requires the spillway to be capable of conveying the peak outflow resulting from a flood generated by a rainstorm comprising 60% of the probable maximum precipitation (PMP).
A number of options were considered for upgrading the spillway capacity, but this paper focuses on the chosen option, which comprises:
a 120 ft wide, four-bay labyrinth weir; a short length of plain chute and intermediate stilling basin; and a baffle-chute spillway, discharging to a natural gulley clear of the dam miter.
The paper describes the approach to the hydraulic design of the labyrinth weir, based initially on the empirical approach set out by Tullis et al (1995), then on flow behavior analyses using computational fluid dynamics (CFD), to address the following issues:
the onset of ‘drowning’, impairing the hydraulic performance of the weir; the energy losses through the structure; confirmation of the stage/discharge rating; and the pressures on the structure, in particular guarding against cavitation.
337 Technical Director, Black & Veatch, 69 London Road, Redhill, Surrey RH1 1LQ, UK, [email protected] 338 Senior Hydraulics Engineer, Black & Veatch, 69 London Road, Redhill, Surrey RH1 1LQ, UK, [email protected] 339 Regional Practice Leader, Black & Veatch, 18310 Montgomery Village Avenue, Suite 500, Gaithersburg, MD 20879, [email protected]
221 NOTES
222 PIANO KEY WEIR HYDRAULICS
Ricky M. Anderson340 Blake P. Tullis341
ABSTRACT
A piano key (PK) weir is a modified labyrinth-type weir designed specifically for spillways with relatively smaller footprints (e.g., gravity dam spillway). The PK weir has a simple rectangular crest layout (in plan-view) with inclined inlet and outlet cycle floors. Where the available footprint for the discharge control structure is limited, additional weir length is produced with a PK weir, relative to traditional labyrinth weirs, by cantilevering the inlet and outlet cycles beyond the structure footprint.
Because of the relatively recent development of the PK weir, a generally accepted standard design procedure is not currently available. This is due, in part, to the large number of PK weir geometric parameters and a limited understanding of their influence on weir performance. Despite this fact, Hydrocoop (France), a non-profit dam spillways association, has suggested a PK weir geometry with a specific inlet-to-outlet cycle width ratio of 1.25 as close to “optimal” for maximizing weir performance; although insufficient support data have been published for independent verification. The design is accompanied with an equation for estimation of the head-discharge relationship.
To develop a better understanding of the effects of PK weir geometry on weir performance, laboratory-scale sectional models with varying inlet-to-outlet cycle width ratios were fabricated and tested. These weirs were tested over a wide range of flows to investigate the sensitivity of PK weir performance to the inlet-to-outlet cycle width ratio. Using test results, the head-discharge equation proposed by Hydrocoop was evaluated.
340 MS Research Assistant, Utah Water Research Laboratory, Utah State University, 8200 Old Main Hill, Logan, UT 84322, [email protected] 341 Associate Professor, Utah Water Research Laboratory, Utah State University, 8200 Old Main Hill, Logan, UT 84322, [email protected]
223 NOTES
224 STRUCTURAL DESIGN FOR SAN VICENTE DAM RAISE
Glenn S. Tarbox, P.E.342 Michael F. Rogers, P.E.343 Vik Iso-Ahola, P.E.344 Bashar S. Sudah, P.E.345 Jim Zhou, P.E346 Mark Schultz, S.E.347
ABSTRACT
The San Diego County Water Authority (Water Authority) has undertaken the Emergency Storage Project (ESP) and Carryover Storage Project (CSP) to increase local reservoir storage in San Diego County, California. The ESP adds local storage in case of a disruption to the imported water supply system which provides more than 90% of the annual local water supply to more than 3 million residents. The CSP storage will be used to store water during “wet” seasons to carry-over for seasons of drought. The San Vicente Dam Raise Project (Project) will meet both reservoir storage needs for a total raise of 117 feet and adding approximately 152,000 acre-feet of new storage.
The existing San Vicente Dam is a 220-foot high concrete gravity dam completed in 1943 with 90,063 acre-feet of storage. The raised San Vicente Dam will be about 337 ft high, creating an approximately 247,000 acre-foot reservoir. The raised portion of the dam will be constructed using roller compacted concrete (RCC).
This paper presents the structural optimization studies that have been performed for the dam raise cross-sectional geometry, utilizing the benefits of the existing dam to minimize materials and provide an economic design. Staged construction thermal and structural analyses were performed to predict concrete temperatures in the dam and to estimate the stress state along the interface of the existing concrete and the new RCC during and after construction using ANSYS 2D finite element analyses. The two dimensional analysis was calibrated with forced vibration test results of the existing dam and used to evaluate the structural stability of the proposed dam design under loads from the Maximum Credible Earthquake (MCE) using time history analysis. Total stresses were computed using the principle of superposition to combine the static stresses from the stage constructed RCC, including the time dependent thermal effects and stresses from the applied hydrostatic and dead weight loading on the structure and the seismic stresses. The analysis output consisted of time history displacement and stress responses during the three applied seismic motions. Stresses within the body of the new composite dam and at the base of the dam were used to develop an optimized geometry for the raised dam.
342 Vice President, MWH Americas Inc., Bellevue, Washington, [email protected]. 343 Vice President, MWH Americas Inc., San Diego, California, [email protected]. 344 Civil Engineer, MWH Americas Inc., Walnut Creek, California, [email protected]. 345 Civil Engineer, MWH Americas Inc., Walnut Creek, California, [email protected]. 346 Design Manager, San Diego County Water Authority, San Diego, California, [email protected]. 347 Supervising Engineer, CA Department of Water Resources, Sacramento, California, [email protected].
225 NOTES
226 GEOLOGIC CHARACTERIZATIONS OF SAN VICENTE DAM RAISE
David L. Schug348 Nicola Kavanagh349 Michael Higgins350
ABSTRACT
The San Diego County Water Authority (Water Authority) is undertaking a raise of the existing San Vicente Dam to provide both emergency and carryover storage to increase local reservoir supplies in San Diego County, California. This paper presents the geological investigation and geotechnical testing performed for the dam raise design. The dam site is located in crystalline bedrock of Mesozoic age including Jurassic metavolcanic rocks, and Jurassic-Cretaceous gneissic granodiorite. Key features at the dam site include the geologic contact between the two rock units underlying the dam within the main valley, a mafic dike on the right abutment, and a series of close spaced shears on the left abutment of the raised dam. A saddle dam is underlain by the granodiorite, and is near the geologic contact with the Tertiary Stadium Conglomerate. Hard metavolcanic cobbles comprising the conglomerate will be crushed to produce aggregates for roller compacted concrete to construct the raised and saddle dams.
Subsurface explorations for design included core borings through the existing dam and rock foundation, packer testing, down-hole geophysical surveys and seismic refraction profiles. Geologic mapping was performed to characterize rock discontinuities such as fractures, joints and shears. Piezometers were installed in borings and monitoring wells were constructed downstream of the dam. Laboratory tests were conducted to characterize rock mass properties. The field investigation provided the basis for determining the excavation limits for the raised dam to be founded on slightly weathered or fresh rock and for saddle dam to be on moderately to slightly weathered rock. The test results were also used to evaluate excavation stability and foundation preparation.
348Principal Geologist, URS Corporation, San Diego, California-USA 92108, [email protected] 349 Design Manager, San Diego County Water Authority, San Diego, California-USA 92123, [email protected] 350 Geologist, URS Corporation, San Diego, California-USA 92108, [email protected]
227 NOTES
228 GEOTECHNICAL BASIS OF DESIGN FOR THE SAN VICENTE DAM RAISE
Leo D. Handfelt351 Kelly C. Giesing352 Melissa Cox353 Jim Zhou354
ABSTRACT
The San Diego County Water Authority (Water Authority) is undertaking a raise of the existing San Vicente Dam to provide both emergency and carryover storage to increase local reservoir supplies in San Diego County, California. This paper presents the geotechnical basis of the dam raise design that includes a thorough site characterization based on extensive subsurface explorations and laboratory testing results. The rock mass properties (modulus of elasticity, modulus of deformation, Poisson’s ratio, strength), rock discontinuity properties (frequency, roughness, infilling, strength), and rock hydraulic conductivity were investigated and formulated based on the results of the site characterization.
Geotechnical design considerations included foundation preparation, response, grouting, and drainage. The foundation preparation included the required depth of excavation for the dam to be founded on slightly weathered or fresh rock, excavation stability, and surface treatments. The foundation response evaluation included the bearing capacity of the rock, base sliding along discontinuities in the rock, and foundation deformations due to the weight of additional concrete from the raised dam. Seepage analyses were performed to determine the foundation grouting and drainage requirements.
351 Principal Geotechnical Engineer, URS Corporation, San Diego, CA, [email protected] 352 Project Geotechnical Engineer, URS Corporation, San Diego, CA, [email protected] 353 Civil/Geotechnical Engineer, URS Corporation, San Diego, CA, [email protected] 354 Technical Design Manager, San Diego County Water Authority, San Diego, CA, [email protected]
229 NOTES
230 SEISMIC HAZARD EVALUATION FOR DESIGN OF SAN VICENTE DAM RAISE
Leo D. Handfelt355 Ivan Wong356 Nicola Kavanagh357
ABSTRACT
The San Diego County Water Authority (Water Authority) is undertaking a raise of the existing San Vicente Dam to provide both emergency and carryover storage to increase local reservoir supplies in San Diego County, California. This paper presents details of the seismic hazard evaluation that formed the basis for development of strong ground motions that were considered in final design of the dam raise.
This dam is under the jurisdiction of the California Department of Water Resources, Division of Safety of Dams (DSOD) which requires the use of deterministic ground motions for design. However, the earthquake ground motions at the site are largely controlled by background (or random) earthquakes, which cannot be adequately addressed using deterministic methods alone. This prompted the development of supplemental seismic design ground motions based on a probabilistic seismic hazard analysis (PSHA). The PSHA was performed incorporating the latest information on seismic sources and recently developed Next Generation of Attenuation (NGA) relationships. Application of the NGA ground motion relationships resulted in lower estimates of peak ground accelerations than what were obtained based on the previous attenuation relationships due to use of the site-specific shear wave velocities of the foundation materials.
355 Principal Geotechnical Engineer, URS Corporation, 4225 Executive Square, Suite 1600, La Jolla, CA 92037, [email protected] 356 Principal Seismologist, URS Corporation, 1333 Broadway, Suite 800, Oakland, CA 94612, [email protected] 357 Design Manager, San Diego County Water Authority, 4677 Overland Avenue, San Diego, CA 92123, [email protected]
231 NOTES
232 APPLICATION OF CUSTOMIZED CONSTRUCTION-COST INDEX ON THE SAN VICENTE DAM RAISE PROJECT
Geraldo R. Iglesia, Ph.D., P.E.358 P. Timothy H. Dyer359 Aaron S. Rouch360
ABSTRACT
Up until a few years ago, the San Diego County Water Authority (Water Authority) had relied heavily on the Construction Cost Index (CCI) for the Los Angeles area, as published monthly by the Engineering News-Record (ENR), to calculate the present worth of the costs of projects constructed in the past. The problem with directly using the ENR CCI to account for past inflationary effects is that the weighting percentages for various cost components adopted for the ENR CCI may not necessarily reflect the makeup of the project for which construction cost estimates are desired. As it turns out, the cost breakdown on most of the construction projects administered by the Water Authority hardly resembles the weighting percentages used for the ENR CCI published each month. Since around 2006, the Water Authority has been utilizing a customizable economics-based model for tracking and forecasting escalation of construction costs, for planning and administering capital projects. Implemented via readily available spreadsheet software, this model allows for customization of parameters and weighting factors, and also provides a systematic scheme for figuring out reasonable future escalation rates, based on available historical data. This paper presents the application of this customized economics-based indexing of construction costs on the San Vicente Dam Raise project. Use of such customized indexing model on this dam project was particularly helpful in forecasting both short-term and long-term budgetary requirements, which provided robust support for critical decisions involving relatively large capital expenditures.
358 Principal, G2D Resources, LLC, 7966 Arjons Drive, Suite 204, San Diego, California 92126-6361. [email protected]. 359 Cost Estimating Supervisor, San Diego County Water Authority, 4677 Overland Avenue, San Diego, California 92123-1233. [email protected]. 360 Lead Project Scheduler, San Diego County Water Authority, 4677 Overland Avenue, San Diego, California 92123-1233. [email protected].
233 NOTES
234 STAYING DRY — COFFERDAM CHALLENGES ON THE SAN VICENTE DAM RAISE PROJECT
Wayne O. Mac Donell361 Aaron Rietveld362 Gary Olvera363
ABSTRACT
The fabrication, shipping, assembly, installation and dewatering of the San Vicente Lower Level Outlet Cofferdam was a challenge for the Contractor, Barnard Construction Company, Inc. This paper tells how this was accomplished using old ideas with new equipment and quality craftsmanship to bring success to the project. The cofferdam was to be fabricated in Montana, shipped in pieces to San Diego, assembled accurately in 8- foot- high units on-site, bolted together 3 units high and installed on a barge for floating transport to the upstream face of the dam. The units were then lifted off the barges with strand jack lifting beams which could easily lift the entire cofferdam. By lifting and assembling the units together, 11 units were assembled above water under dry conditions that could be checked by the Owner, Contractor and Engineer. After tipping the cofferdam units and setting them in place, anchor bolts were drilled into the dam face, seals were compressed, grout was pumped into a space on the back flange and the cofferdam was pumped dry — all with a minimum of underwater work. The project utilized fabricated cofferdam shells from Midwest Steel Industries, Belgrade MT, anchor bolts from Williams Concrete Form Co., seals from Seals Unlimited, Beaverton OR, a 350-ton Grove Hydraulic Truck Crane from Maxim Crane, a strand jack lifting system from Barnhart Crane & Rigging of Memphis TN, a Manitowoc 888 Crawler Crane from Bragg Crane, Flexifloat barges from Robishaw Engineering, Inc of Houston, TX and engineering design from Ben C. Gerwick, Consulting Engineers of Oakland, CA.
361 Senior Engineer, Ben C. Gerwick, Inc. 1300 Clay St. 7th Floor, Oakland, CA 94612, (510) 267- 7176, [email protected] 362 Project Manager, Barnard Construction Company, Inc. 701 Gold Ave, Bozeman, MT 59771, (406) 586- 1995, [email protected] 363 Construction Manager, San Diego County Water Authority, 4677 Overland Ave. San Diego, CA 92123, (619) 390 2310, Ext. 3327, [email protected]
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