EM 1110-2-2300 30 July2004 US Army Corps of Engineers® ENGINEERING AND DESIGN General Design and Construction Considerations for Earth and Rock-Fill Dams ENGINEER MANUAL AVAILABILITY Electronic copies of this and other U.S. Army Corps of Engi- neers (USACE) publications are available on the Internet at http://www.usace.army.mil/inet/usace-docs/. This site is the only repository for all official USACE engineer regulations, circu- lars, manuals, and other documents originating from HQUSACE. Publications are provided in portable document format (PDF). DEPARTMENT OF THE ARMY EM 1110-2-2300 U.S. Army Corps of Engineers CECW-EG Washington, DC 20314-1000 Manual No. 1110-2-2300 30 July 2004 Engineering and Design GENERAL DESIGN AND CONSTRUCTION CONSIDERATIONS FOR EARTH AND ROCK-FILL DAMS Subject Paragraph Page Chapter 1 Introduction Purpose............................................................................................................................1-1 1-1 Applicability...................................................................................................................1-2 1-1 References.......................................................................................................................1-3 1-1 Overview of Manual.......................................................................................................1-4 1-1 Chapter 2 General Considerations General............................................................................................................................2-1 2-1 Civil Works Project Process...........................................................................................2-2 2-2 Types of Embankment Dams..........................................................................................2-3 2-3 Basic Requirements........................................................................................................2-4 2-5 Selection of Embankment Type......................................................................................2-5 2-7 Environmental Considerations........................................................................................2-6 2-8 Chapter 3 Field Investigations and Laboratory Testing Geological and Subsurface Explorations and Field Tests...............................................3-1 3-1 Laboratory Testing..........................................................................................................3-2 3-4 Chapter 4 General Design Considerations General............................................................................................................................4-1 4-1 Freeboard........................................................................................................................4-2 4-3 Top Width.......................................................................................................................4-3 4-3 Alignment.......................................................................................................................4-4 4-3 Embankment...................................................................................................................4-5 4-3 Abutments.......................................................................................................................4-6 4-3 Performance Parameters.................................................................................................4-7 4-4 Earthquake Effects..........................................................................................................4-8 4-5 Coordination Between Design and Construction............................................................4-9 4-5 Value Engineering Proposals..........................................................................................4-10 4-6 Partnering Between the Owner and Contractor..............................................................4-11 4-6 i EM 1110-2-2300 30 Jul 04 Subject Paragraph Page Modifications to Embankment Dams to Accommodate New or Revised Inflow Design Floods or to Provide Additional Storage for Water Supply or Other Purposes............................................................................................................4-12 4-7 Chapter 5 Foundation and Abutment Preparation Preparation......................................................................................................................5-1 5-1 Strengthening the Foundation.........................................................................................5-2 5-3 Dewatering the Working Area........................................................................................5-3 5-3 Chapter 6 Seepage Control General............................................................................................................................6-1 6-1 Embankment...................................................................................................................6-2 6-1 Earth Foundations...........................................................................................................6-3 6-1 Rock Foundations...........................................................................................................6-4 6-5 Abutments.......................................................................................................................6-5 6-6 Adjacent to Outlet Conduits............................................................................................6-6 6-6 Beneath Spillways and Stilling Basins............................................................................6-7 6-6 Seepage Control Against Earthquake Effects.................................................................6-8 6-7 Chapter 7 Embankment Design Embankment Materials...................................................................................................7-1 7-1 Zoning.............................................................................................................................7-2 7-2 Cracking..........................................................................................................................7-3 7-3 Filter Design....................................................................................................................7-4 7-8 Consolidation and Excess Porewater Pressures..............................................................7-5 7-8 Embankment Slopes and Berms.....................................................................................7-6 7-9 Embankment Reinforcement..........................................................................................7-7 7-9 Compaction Requirements..............................................................................................7-8 7-10 Slope Protection..............................................................................................................7-9 7-14 Chapter 8 Appurtenant Structures Outlet Works...................................................................................................................8-1 8-1 Spillway..........................................................................................................................8-2 8-1 Other Important Considerations......................................................................................8-3 8-2 Chapter 9 General Construction Considerations General............................................................................................................................9-1 9-1 Obtaining Quality Construction......................................................................................9-2 9-1 Stage Construction..........................................................................................................9-3 9-2 Stream Diversion............................................................................................................9-4 9-2 Closure Section...............................................................................................................9-5 9-3 Construction/Design Interface........................................................................................9-6 9-4 Visual Observations........................................................................................................9-7 9-4 Compaction Control........................................................................................................9-8 9-4 ii EM 1110-2-2300 30 Jul 04 Subject Paragraph Page Initial Reservoir Filling...................................................................................................9-9 9-5 Construction Records and Reports..................................................................................9-10 9-6 Chapter 10 Instrumentation General............................................................................................................................10-1 10-1 Instrumentation Plan and Records..................................................................................10-2 10-1 Types of Instrumentation................................................................................................10-3 10-3 Discussion of Devices.....................................................................................................10-4 10-3 Measurements of Seepage Quantities.............................................................................10-5 10-4 Automated Data Acquisition Systems............................................................................10-6 10-4 Appendix A References Appendix B Filter Design Appendix C Slope Protection Appendix D Automatic Data Acquisition Systems Appendix E Process for Establishing Performance Parameters Appendix F Methods of Dam Raising iii EM 1110-2-2300 30 Jul 04 Chapter 1 Introduction 1-1. Purpose This manual presents fundamental principles underlying the design and construction of earth and rock-fill dams. The general principles presented herein are also applicable to the design and construction of earth levees. The construction of earth dams by hydraulic means was curtailed in the 1940's due to economic considerations and liquefaction concerns during earthquake loading and are not discussed herein. 1-2. Applicability This manual applies to HQUSACE elements, major subordinate commands, districts, laboratories, and field operating activities having responsibility for the design and construction of earth and rock-fill dams. 1-3. References Required and related publications are listed in Appendix A. 1-4. Overview of Manual The objective of this manual is to present guidance on the design, construction, and performance monitoring of and modifications to embankment dams. The manual presents general guidance and is not intended to supplant the creative thinking and judgment of the designer for a particular project. The increased development and expansion of the population in the Nation’s watersheds have created a definite need to develop additional water supply. In many areas the existing national infrastructure cannot meet these needs. The increase in urban development has also had a negative impact on water quality. The public is asking that preservation of the environment be an equal goal with the economic benefits of water resources projects. Since the current infrastructure is not meeting public needs, this situation is placing lives, livelihood, and property at risk. Several options are available to provide the additional quantity of water. The simplest and most cost-effective method to obtain the quantities needed is to add additional storage at existing dams. Many of the Nation’s existing water resources projects must be modified to add the additional purpose of water supply. In the future, USACE designers will be challenged with requests by the customers and sponsors to modify existing dams to add water supply to other purposes of existing dams. These modifica- tions must include environmental considerations and mitigation. 1-1