Dam–reservoir interaction effects on the elastic dynamic response of concrete and earth dams

•The effects of elastic dam–reservoir interaction (DRI) on dams are investigated.•Both thin rectangular concrete and large trapezoidal earth dams are considered.•DRI effects are more important for concrete than earth dams.•DRI changes the fundamental period of the dam and the amplification of accelerations.

The relative effects of dam–reservoir interaction on the dynamic response of concrete and earth dams are studied. The amplification of accelerations at the dam crest is explored under harmonic acceleration load. For certain cases of concrete dams the accelerations can be significantly affected by the upstream reservoir, whereas this influence is smaller for earth dams.