SEISMIC RESPONSE ON SOFT SEMI-SPHERICAL ALLUVIAL DEPOSITS : The case of incident plane SH waves

Abstract

This paper presents the three − dimensional responses on soft semi − sphericai alluvial deposits under incidence of plane SH waves ． In し his analysis ， we modify the wave potential functions to estimate the exact solution without great computational capacity and cost ． The computed results show that 出 e seismic responses depend strongly on the aUuvial deposit depth varying along the curved boundary ． It is found that the scattering waves due to the curved boundary induce surface waves in alluvial deposits ， which are more developed as the incident angle decreases． Seismic responses show significant variations with the incident angle ， station location and impedance contrast ratio even for the simple idealized deposit model ． ． The above results suggest the formation of seismic ground motions in three − dimensional soft alluvial deposits with topographic irregular boundary ． Keyweizts ：three −dimensional resPonse ， 5 ε加 一 3 カ ゐ θ厂加 ！6 〃麗 擁 α 1 伽 ∫1 ε ∫ ， S万 wave ， Ztnne Potential ftinc − tions ， scattering wave ， imPeeinnce contrast ratio 3