The Scattering Of Seismic Waves By The Basin-mountain Coupling Terrain

The problem of site response when the seismic waves attack has always been animportant issue in earthquake engineering,while the problem of site response whenthe local terrain exists owns more attention by the majority of the scholars. Amongthem, the basin-mountain terrain is one of the typical ones.The significant impact ofground motion by the sedimentary basins and mountains has been confirmed byobservational and theoretical facts,but the composite action of both still needs to bequantified.This article is based on the single-layer potential theory.First,we use a kind ofhigh-precision dynamic boundary element method to solve the scattering of SH wavesby the basin-mountain coupling terrain.Then,we use a kind of coupling method ofboundary element and finite element to study the scattering problems of P waves,SV waves and Rayleigh waves by the mountain and the basin-mountain couplingterrain. Through detailed parametric analysis,we study the impact mechanisms of theamplitude and spectrum of ground motion by the spatial location and the geometriccharacteristics of the basin or the mountain,the frequency and angle of the incidentwaves and other factors.Research shows that the impact of SH waves, P waves and Rayleigh waves bythe basin-mountain coupling site is very significant.The amplitude of surfacedisplacement depends mainly on the frequency of the incident wave,the angle of theincident wave and the interactions of the basin-mountain coupling site.In all, with the frequency of incident wave increases,the shock of the amplitudeof the surface displacement exacerbates and the surface displacement of thebasin-mountain coupling site becomes more complex.And with the angle of theincident waves,the shock of the side of basin site exacerbates.As with the side of thebasin site, when the seismic waves come from the horizon,the mountain performs assome kind of barrier,and with the increasing height of the mountain, the barrier effectis more apparent.