FEM -IBIEM coupled method for simulating scattering of seismic waves by 3-D complex local site

A hybrid technique, FEM-IBIEM is developed for studying the scattering of seismic waves by a 3-D complex local site. The indirect boundary integral equation method (IBIEM) adopts the dynamic Green's functions of concentrated loads for a layered half-space. It can accurately satisfy the radiation condition of waves in semi-infinite layered media and greatly reduce the computational memory. For the local site with complex materials and geometric features, FEM is more convenient. Based on accuracy tests and taking the seismic wave scattering resulting from 3-D sedimentary basins and mountains as the example, the adaptability of the proposed method for the seismic response in the complex local site is conformed, and several beneficial conclusions about the 3-D sedimentary basin effects and mountain vibration are drawn. This method can be used for studying the scattering of elastic waves by arbitrary inhomogeneous site in layered half-space.