INFLUENCE OF UNDERGROUND CAVITY ON THE SEISMICRESPONSE OF U-SHAPED CANYON USING BEM

A 2D scattering and diffraction of plane P and SV waves induced by a U-shaped canyon above underground cavities is proposed herein to account for the topographic effect of such a canyon. Time domain boundary element method(BEM),were performed to study the behaviour of this problem. To show the interaction between U-shaped canyons and underground cavities and their effects on the surface ground motion, a parametric analysis is carried out in very long periodic bands.Influence of various parameters has been investigated. It is shown that site geometry, wave characteristics, and cavity location are the key parameters governing the canyon’s response. In this regard, the important parameters considered in this study are: the width of the underground cavities; the cavity depth; radios of cavity and shape of canyon.