Nonlinear Seismic Analysis of an Arch Dam Subjected to Very Intensive Earthquake Loading

Abstract

This paper presents the results of a state-of-the-art dynamic analysis where a nonlinear seismic analysis of an existing arch dam under an intense earthquake was recently performed. The 3D finite element model was developed and the analysis performed using the explicit finite element program LS-DYNA. This 3D model includes the effects of dam-foundation-reservoir interactions. Also, rock wedges within the abutments were modeled to simulate potential abutment block sliding. Non-reflecting absorbing boundaries were modeled along the foundation sides and the reservoir extents. The vertical contraction joints and the dam-foundation interface were modeled with contact elements capable of opening and closing along with sliding. Additionally, a nonlinear concrete model was used to simulate the concrete cracking during the earthquake. Finally, the analysis was performed under an intense earthquake with a peak ground acceleration (PGA) of about 0.9g. The results of this analysis are a reasonable match to the simulated failure mode created by a scaled shake table test of similar arch dams.