Seismic analysis of a coupled dam-reservoir-foundation system considering pressure effects at opened joints

Abstract

In this paper, seismic response of a coupled dam-reservoir-foundation system is investigated under different types of artificially generated ground motions. Nonlinear behaviour of the arch dam is originated by modelling the vertical contraction and the curved peripheral joints based on discrete crack approach. Fluid–structure dynamic interaction is modelled based on Euleian–Lagrangian approach and the hydrodynamic pressure effect is considered inside the opened joints during the seismic action using heuristic approach. Foundation rock is modelled as massed medium and the viscous boundary model is applied on the exterior surface of the foundation finite element model. Artificial ground motions are applied to the coupled system using different durations and intensities. Various ground motion intensity measures (IMs) and engineering demand parameters (EDPs) are used for interpretation of the parametric study. It is shown that almost in all cases considering the pressure effect inside the joints, the demand parameter increases. Nonlinear behaviour of arch dams is sensitive not only to ground motion intensity but also its duration. This study shows that the specific energy density is the most appropriate IM almost for all the EDPs of concrete arch dams.