Estimation of Potential Seismic Displacements of Embankment Dams

While displacements in embankment (earthfill/rockfill) dams can occur due to volume changes and/or due to shear deformations and can be caused by seismic or non-seismic events, this presentation will only cover displacements due to shear deformations induced by a seismic event. Such deformations can be induced during shaking and/or after shaking had stopped.

This presentation explores analytical approaches and empirical methodologies used to estimate seismically induced displacements in embankment dams and will summarize available procedures for conducting such evaluations. These include the use of nonlinear and equivalent linear dynamic analyses and a variety of "simplified approaches". These simplified approaches range from the possible use of empirically based charts to more direct estimation of the seismic driving force on a selected segment (slice) of the embankment or the embankment-foundation system.

Drawing on decades of research and practical experience, the presentation outlines the factors that influence dam performance during earthquakes, including ground motion characteristics, dam geometry, and material properties. Special attention is given to the development of dynamic analyses and the simplified approaches, the assessment of case histories, and the integration of field and laboratory observations to enhance the reliability of displacement estimations.