关键词: 凸起地形, 横观各向同性, 格林函数, 平面qP-qSV波, 间接边界元法

Abstract: To investigate scattering of plane qP-qSV waves induced by a convex topography with the transversely isotropic (TI) medium, the indirect boundary element method (IBEM) is used for the numerical simulation and the solutions of the plane qP-qSV waves scattering problem in both the frequency and time domain are given, respectively. In the process of solving, the calculation model is divided into open layered half-space region and close hill region, and the wave field is decomposed into free wave field and scattered wave field, the first of which can be solved by the direct stiffness method, and the second can be simulated by the dynamic Green’s function by applying the fictitious inclined uniformly distributed load. The results in frequency domain show that the different TI media can change the dynamic characteristics of hill and layered half-space, and alter the dynamic interaction mechanism between hill and layered half-space, making the surface displacements significantly different. The results in time domain indicate that the parameters of the TI media and incident directions of plane waves have significant effects on the propagation of qP-qSV waves around the hill. In addition, time domain results clearly show the transmission process of incident, reflected and scattered waves.

Key words: convex topography, transversely isotropic, Green’s function, qP-qSV waves, indirect boundary element method