Materials for Embankment Dams - USSD

1 United States Society on Dams Materials for Embankment Dams January 2011. United States Society on Dams Materials for Embankment Dams January 2011. Prepared by the USSD Committee on Materials for Embankment Dams Society on Dams Vision To be the nation's leading organization of professionals dedicated to advancing the role of dams for the benefit of society. Mission USSD is dedicated to: Advancing the knowledge of dam engineering, construction , planning, operation, performance, rehabilitation, decommissioning, maintenance, security and safety.

2 Fostering dam technology for socially, environmentally and financially sustainable water resources systems;. Providing public awareness of the role of dams in the management of the nation's water resources;. Enhancing practices to meet current and future challenges on dams; and Representing the United States as an active member of the International Commission on Large Dams (ICOLD). The information contained in this report regarding commercial products or firms may not be used for advertising or promotional purposes and may not be construed as an endorsement of any product or firm by the United States Society on Dams.

3 USSD accepts no responsibility for the statements made or the opinions expressed in this publication. Copyright 2009 U. S. Society on Dams Printed in the United States of America ISBN 978-1-884575-49-5. Library of Congress Control Number 2009942447. Society on Dams 1616 Seventeenth Street, #483. Denver, CO 80202. Telephone: 303-628-5430. Fax: 303-628-5431. E-mail: Internet: FOREWORD. The USSD Committee on Materials for Embankment Dams has prepared this White Paper on Materials for Embankment Dams. The paper provides an outline of important points that need to be recognized and understood when selecting material for use in Embankment dams.

4 It covers soil Materials ; rockfill Materials ; granular filters and drains;. asphalt concrete as a water barrier; concrete facing rockfill dams; geosynthetics;. reinforced fill; upstream slope protection; material for watertight cutoffs; and construction issues. For each of these topics, design and construction considerations are presented. USSD Committee on Materials for Embankment Dams Craig W. Harris, Chair Ralph W. Rabus, Vice Chair William H. Allerton Michael C. Canino Dean B. Durkee John W. France Edwin R. Friend Garry H.

5 Gregory Gregory J. Hanson Carlos A Jaramillo David E. Kleiner Richard W. Kramer Danny McCook Debora J. Miller Ali M. Oskoorouchi Del A. Shannon Michael K. Sharp Christopher Slaven Justin Frederick Smith Richard L. Volpe Randal G. Pool i TABLE OF CONTENTS. 1. INTRODUCTION ..1. Historical Perspective ..1. Basic Requirements of the Embankment Dam ..2. Embankment Dam Underlying Concepts ..4. 2. SOIL Fine Grained Soils (Silts and Clays)..7. General Characteristics and Index Properties ..7. Shear Compressibility ..9. Earthquake Resistance.

6 9. Dispersive Clays ..10. Coarse Grained Soils (Sands and Gravels) ..10. General Characteristics and Properties ..11. Hydraulic Conductivity (Permeability)..11. Relative Surface Erosion Liquefaction Broadly Graded General Characteristics and Properties ..14. material Internal Erosion and Piping ..15. Earthquake-Induced Settlements ..16. design and construction Fine Grained Coarse Grained Broadly Graded 3. ROCKFILL Materials ..23. Requirements of Rock as a construction material ..23. Determining Engineering Properties of Rockfill.

7 25. Compacted Unit Weight ..26. Compressibility ..26. Hydraulic Shear Strength and Durability ..29. Rockfill material design and construction Concerns ..30. ii 4. GRANULAR FILTERS AND DRAINS ..35. Underlying Principles Basic Requirements of Filters and Drains in Dams ..35. Flow Conditions Acting on Filter Research ..38. design Requirements of Filters ..41. Base Soil Analysis ..41. Retention Permeability Discharge Capacity ..43. Segregation ..44. Self-Healing by Collapse ..45. Ability to Control a Crack in the Core material .

8 45. Critical Filter to Protect the construction Practice ..47. Width of Filters ..47. Compaction Segregation Problems ..48. Filter Contamination ..48. Change in Properties during Quality Control Unclear Specifications ..49. Inadequate construction Resultant Unsatisfactory Structure ..50. 5. ASPHALT CONCRETE (AC) AS THE WATER BARRIER IN. Embankment DAMS ..53. Water Barrier ..53. The AC Core ..53. The AC Materials ..56. Asphalt ..56. Asphalt Concrete Materials Testing ..60. design Tests of Asphalt ..60. Tests of Aggregate.

9 61. Tests of Filler ..62. Tests of Asphalt Concrete Frequency of Quality Control Testing ..63. iii 6. CONCRETE FACING FOR ROCKFILL design ..67. Typical Section ..67. Materials ..68. Types of Materials ..68. Aggregates ..69. Cement ..69. Additives ..69. Concrete ..69. Earthfill ..70. Granular Rockfill Zone 3 ..71. Compacted Rockfill ..71. Compaction ..72. Density ..72. Grading ..73. Shear Modulus ..74. Reinforcing ..74. Protection of Zone 7. Geosynthetic Materials ..77. Geotextiles ..78. Geomembranes ..78. Other Engineering Considerations.

10 80. Mechanical Loads ..81. Physical, Chemical and Biological Geomembranes for Earth Dam Water Dam Embankment Subgrade ..83. Base Layer ..84. Supporting Layer ..84. Geomembrane ..85. Protective Layer ..86. iv Quality Control and Performance Repair of Earth Dam Concrete Facings ..87. Geomembranes for Concrete Dam Water Geotextiles as Filters in Fill Possible Applications of Geotextiles as Filters in Earth Principles of Filtration ..89. Differences Between Geotextile Filters and Granular Opening Sizes of Filter design Criteria for Geotextiles.