Nonlinear seismic response of a concrete arch dam to spatially varying earthquake ground motions

Spatially uniform ground motion is an assumption that is often made for structural analyses of arch dams. However, it has been recognized for many years that the ground motion is non-uniform due to large distances between the supports of structures such as bridges and dams. In this paper, a comprehensive investigation on the seismic response of dam-reservoir-foundation systems subjected to spatially varying ground motions is represented. Monte Carlo simulation approach is utilized for generating spatially non-uniform ground motions. A high arch dam is selected as numerical example to investigate nonlinear seismic behaviour of the coupled system. Reservoir is modelled as compressible material and the foundation is supposed to be mass-less medium. Seismic responses of the dam due to incoherency and wave passage are investigated. According to the results, the non-uniform input produces a response that is substantially different from the response produced with uniform input and can increases the structural response of the system.