A framework for seismic response analysis of dams using numerical source-to-structure simulation

Abstract

The determination of spatially-varying broadband ground motions is a prerequisite for the seismic analysis of dams. However, generating realistic ground motions at a specific dam site remains a challenge. Source-to-structure simulation, which considers source, propagation path, and site, is a promising way to reasonably synthesize site-specific ground motions. This paper proposes a practical framework for the seismic analysis of dams based on a deterministic numerical source-to-structure simulation. The site-specific broadband ground motions are generated by a physics-based 3D numerical simulation using the spectral element method (SEM) in a coarse mesh, while the nonlinear dynamic response of the dam is simulated by the finite element method (FEM) in a fine mesh. The proposed framework bridges the gap between wavefield simulation and seismic analysis of dams. The seismic response analysis of Pacoima dam during the 1994 Northridge earthquake was conducted as a case study, making it the first demonstration of a complete source-to-structure simulation for realistic concrete dams using the purely numerical method. Results show that the calculated seismic response agrees with the observation, thus indicating the utility of the proposed framework for source-to-dam simulation.