Earthquake damage analysis of arch dams considering dam–water–foundation interaction

Abstract

A comprehensive model is integrated in this paper to analyze the nonlinear earthquake response of arch dams. The following factors are taken into account: the semi-unbounded size of foundation rock and compressible water, the opening of contraction joints, the cracking of the dam body, and the spatial variation of ground motions. As a case study, the earthquake response of the Pacoima dam to the 1994 Northridge earthquake is investigated using the proposed model. The earthquake damage is simulated based on the actual conditions during the earthquake to verify the developed analysis model. The joint opening and concrete cracking are qualitatively reproduced, wherein the ground motion excitation is spatially defined based on the acceleration records at the dam–rock interface. Several influencing factors, such as the earthquake input mechanism, shape of the thrust block, and water level, are further considered to analyze their contribution to the actual damage. The result shows that the variation of ground motions along the dam–foundation interface may be the most important factor for the damage mode of the Pacoima dam.