ABSTRACT
Earthquake-induced failures have occurred in several dams which were indicated by the pseudo-static approach to have adequate seismic stability, largely because the method provides no means for taking into account the effects of pore-pressures generated by earthquake shaking and the resulting reduction in strength of the soils on the stability of the embankment. The selection of an appropriate time-history of earthquake excitation at the base of the dam or in an adjacent rock outcrop is thus an important part of the analysis procedure. A good understanding of the general characteristics of strong earthquake shaking is thus an essential component of any analysis to be used for practical purposes. In recognition of the many factors involved, the writer has for many years used an analysis approach which seems to embody most of the essential elements of a seismic safety evaluation procedure for embankment dams.
