Dynamic response of concrete gravity dams including dam–water–foundation interaction

Abstract

AbstractIn this paper, the gravity dam–water–foundation system including the physical and mechanical properties of the sediment at the reservoir bottom is modelled using a finite element and infinite element coupling model. The sediment at the reservoir bottom has been assumed to be a viscoelastic solid medium. The effects of thickness, elastic modulus, Poisson's ratio and material damping of the sediment on the response of the dam have been studied. The related numerical results from this study illustrated that the existence of the sediment at the bottom of the reservoir has significant effects on the response of concrete gravity dams since the soft layer of the sediment plays two main roles in the dam–water–foundation system, the energy dissipation of the system and the amplification of the incident wave on the water–sediment interface. It is the amplified acceleration on the water–sediment interface that results in different mechanisms of the effect of the sediment on the response of the dam. Therefore, apart from the incident wave, the thickness, the softness and the damping ratio of the sediment can also affect the response of the dam.