Response of Dams to Earthquakes Including Effects of Sediments

Abstract

Using a technique based on the boundary element method, results are obtained for two‐dimensional dam‐water‐sediments‐foundation systems subjected to ground motion. Both deep‐stratum and half‐space idealizations of the foundation are considered. The results confirm the findings of previous investigations with respect to dam‐water and dam‐foundation interactions. However, they are in contrast with some of the results of an earlier study obtained using the so‐called “wave reflection coefficient” approach when considering dam‐water‐foundation systems. Specifically, in the case of a half‐space foundation and a full reservoir, the “wave reflection coefficient” approach leads to substantial underestimation (approximately 24% for the system considered) of the peak value of the crest horizontal acceleration due to time‐harmonic horizontal ground motion. Apparently, this is due to the excessive damping introduced into the dam‐water‐foundation system by the absorbing boundary condition imposed on the bottom of the reservoir in the “wave reflection coefficient” approach.