This report is intended to provide guidance on the evaluation of seismic deformations of embankment dams and on the use of numerical analysis procedures for such evaluations. It is intended to serve as a reference on available analysis methods for consultants, regulators, and owners involved in performing, reviewing, and procuring analyses of seismic stability and deformations of embankment dams. Because engineering practice in this field will likely continue to evolve rapidly, this guidance is expected to require periodic review and updating in the future.
Comprehensive closure planning for existing, new, and legacy Tailing Storage Facilities (TSFs) requires a thorough understanding of closure criteria and objectives. Closure regulations of states with significant mining activities in the United States of America (USA) were reviewed, along with tailings dam regulations promulgated by federal agencies to determine how they compare with industry practice. The authors also compared USA closure regulations with the closure criteria of international industry and professional organizations to understand the alignment or misalignment with the endorsed practices. This white paper discusses the industry practice and regulations of TSF closure for legacy and new mine sites. The purpose is to educate and inform the United States mining community regarding transitioning a tailings dam from operation to closure safely and environmentally responsible, considering its potential as a beneficial asset to the community.
This document presents a philosophy of foundation surface preparation and treatment of dam foundations and discusses various preparation methods. Various types of dams include earthfill and rockfill embankment dams, concrete gravity and arch dams. The document discusses surface preparation of rock and soil foundation materials for placement of embankment and surface preparation of rock foundations for placement of concrete or roller-compacted concrete (RCC). Foundation preparation methods include excavation; shaping the rock foundation surface with dental concrete or shotcrete; filling rock surface irregularities and defects with slush grout or dental concrete; treating fault, shear, or weak zones; and foundation cleaning. Special compaction requirements for the first several layers of earthfill placed on a foundation of embankment dams are also presented.
Prepared by the USSD Embankment Dams Committee
This White Paper presents a brief overview and summary of the topic of internal erosion in dams and their foundations, drawing extensively from other relevant publications. This guidance document is not intended to provide comprehensive coverage of the subject, but instead presents a general overview with some basic definitions and representative case studies, as well as annotations or recommendations for suggested references that readers can access to further educate themselves. Included in this White Paper is a brief description of internal erosion with general descriptions of the pathways through which a developing failure may occur, and a general description of the process and progression of internal erosion leading to a dam failure. Also included is clarification of how the term “piping” is often misused to describe various internal erosion mechanisms.
This series of White Papers by the USSD Committee on Monitoring of Dams and Their Foundations addresses important topics with respect to the development and successful implementation of dam safety monitoring programs. The papers in the series are available for download below:
Risk Management for Dam Construction was prepared by the USSD Committee on Construction and Rehabilitation. This White Paper uses and adapts accepted Project Risk Management techniques for new dams and dam rehabilitation projects. It discusses the formal Risk Management process, identifies risk categories for dam construction, reviews strategies to manage risks, and presents several case studies where risk management strategies were employed. It was written for engineers, owners, and contractors engaged in the planning, design, and construction of dam-related projects anticipated to cost anywhere from $20 million to over $500 million.
USSD recognizes that with an aging infrastructure, additional demands are being placed on dam owners to ensure safe and reliable operation of their dams. In support of this goal, proper equipment selection, regularly scheduled maintenance, and test-operation of equipment are key elements in determining condition and operational capability of valves. Failure to operate valves upon demand can affect the overall dam safety of a project. The USSD Hydraulics Committee commissioned its Subcommittee on Gates and Valves to develop this technical report as a source of practical experience and information to achieve long-term reliability of valves at dams.
The USSD Committee on Dam Decommissioning has prepared these Guidelines to provide dam owners, dam engineers, and other professionals with the information necessary to help guide decision-making when considering dam removal as a project alternative. The Guidelines will help in the development and execution of a successful dam decommissioning project, which would include all necessary activities associated with the removal of a dam and restoration of the river, from project planning through design and implementation.
This report, prepared by the USSD Committee on Hydraulics of Dams, Subcommittee on Reservoir Sedimentation, describes application of mathematical models to reservoir sedimentation, including the issues of selecting an appropriate transport function, sediment delivery to reservoirs, deposition patterns, and modeling specific reservoir sediment management strategies.
Guidelines for Construction Cost Estimating for Dam Engineers and Owners was prepared by the USSD Committee on Construction and Rehabilitation. The White Paper provides support for responsible cost estimating for new dams and dam rehabilitation projects. It has been written for engineers and owners engaged in the planning, design and construction of dam-related engineering projects anticipated to cost up to $100 million. This represents the collaborative effort of representatives from federal agencies, public utilities, private engineering companies and construction contractors. Stages of project design and associated estimates, the development of a work breakdown structure, direct and indirect project costs, overhead, contingency, profit, and other owner costs are addressed as they relate to responsible cost estimating. Examples of Work Breakdown Structures for various sized projects are also presented.
The USSD Committee on Earthquakes has published three reports on this topic since 1992. Volume I includes general observations on the performance of embankment and concrete dams, along with 11 case histories and a table with a comprehensive listing of dams affected by earthquakes. Volume II (2000) provides an updated commentary, and contains 12 case histories and an updated table. Volume III (2014), as with the earlier two volumes, includes general observations, an updated table and detailed descriptions of observed performance for 12 selected dams. In addition, a Bibliography on Performance of Dams During Earthquakes was published in 1984.
There are three volumes available for download here:
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. 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.
Is a White Paper prepared by the USSD Committee on Materials for Embankment Dams. The White Paper is of interest to owners of dams and those responsible for the safety of existing dams. The report notes that there are aging processes, and a project may develop aging characteristics which need to be examined, studied and remedied to preclude a safety issue.
Is a white paper prepared by the USSD Committee on Materials for Embankment Dams. The paper is intended to be a “living document” that presents the “state of the practice” for determining fill strength parameters for earthfill embankment dams and the static analysis of embankment dams.
The Executive Summary of Planning Processes for the Development of Dams and Reservoirs – Public Involvement and Alternatives Analysis: A Framework for Successful Decision-Making is based on a USSD White Paper that is now available. The White Paper presents a multidisciplinary decision-making process for the development of dams and reservoirs focusing on public involvement and the analysis of alternatives.
The 2003 White Paper’s overall purpose is “To assess the state-of-the-practice in dam safety risk assessment, and to provide commentary on appropriate types of applications and ways to facilitate and strengthen its use.” The White Paper is neither a “how to” guide nor a standard of practice.