A reflection-transmission matrix method for time-history response analysis of a layered TI saturated site under obliquely incident seismic waves

Abstract

This paper proposed a reflection-transmission matrix method to solve the time-history response of a layered transversely isotropic (TI) saturated site subjected to obliquely incident seismic waves. Based on Biot's theory of wave propagation in a TI poroelastic medium, the displacement, stress and pore pressure components are derived in the frequency domain using the boundary and continuity conditions of the layered half-space. By employing inverse Fourier transform and convolution theorem, time-domain solution for the site response under earthquake excitation is given. The methodology is implemented by the numerical platform FORTRAN, and is verified through comparison with degenerated solution for a layered isotropic single-phase case. Taking single-layered and multi-layered half-space as the examined models respectively, the time-history response of the stratified TI saturated site under obliquely incident seismic waves are presented and parameters studies are performed. Numerical results illustrate that the TI parameters, earthquake excitation, incident angle, and layering sequence have significant important influence on the seismic responses. The presented solutions can provide effective reference for studying the input ground motion and seismic soil-structure interaction concerning specially the layered TI saturated site.