The Earthquake Engineering Online Archive

A simplified procedure for estimating earthquake-induced deformations in dams and embankments

Makdisi, Faiz I.; Seed, H. Bolton

UCB/EERC-77/19, Earthquake Engineering Research Center, University of California, Berkeley, 1977-08, 65 pages (480.2/M21/1977)

The inadequacy of the pseudo-static approach recommended by the International Committee on Large Dams to predict the behavior of low embankments during earthquakes has been clearly recognized and demonstrated. The committee pointed out the need for early revision of the method, which, in several instances, predicted a safe condition for dams which were known to have had major slides. This report presents a simplified procedure for the seismic design of small embankments. The method is an approximate one which uses the concept, originally proposed by Newmark, for calculating permanent deformations; but it is based on an evaluation of the dynamic response of the embankment rather than on rigid body behavior. The method is applied to dams with heights in the range of 100 to 200 ft and constructed of compacted cohesive soils or very dense cohesionless soils. Design curves on the basis of analyzed cases are presented with an example problem. The method is an approximate one and involves simplifying assumptions. The design curves are averages based on a limited number of cases and should be updated as more data become available. Appendix A of this report is: "A simplified procedure for computing maximum crest acceleration and natural period for embankments."

Available online: http://nisee.berkeley.edu/documents/EERC/EERC-77-19.pdf (2 MB)