Antiplane seismic response from semi-sine shaped valley above embedded truncated circular cavity: a time-domain half-plane BEM

In this paper, normalized displacement amplitude of the ground surface was presented in the presence of the semi-sineshaped valley above the truncated circular cavity embedded in a homogenous isotopic linear elastic half-plane, subjected toobliquely propagating incident sh waves as ricker wavelet type. the proposed direct time-domain half-plane boundaryelement formulation was used and extended to analyze the combined multi-boundary topographic problems. while using it,only boundary of the valley and the surrounding cavity should be discretized. the effect of four geometric parametersincluding shape ratio of the valley, depth ratio, horizontal location ratio and truncation thickness of the cavity and incidentwave angle was investigated on the responses at a single dimensionless frequency. the studies showed that surface behaviorwas completely different due to complex topographic features, compared with the presence of either valley or cavity alone. inaddition, the cavity existence below the surface could play a seismic isolation role in the case of vertical incident waves andvice versa for oblique waves.