Scattering of plane wave by circular-arc alluvial valley in a poroelastic half-space

Abstract

Based on the complex variable function method, a new approach for solving the scattering of plane P wave by circular-arc alluvial valley in poroelastic half-space is developed in the paper. In this analysis, the poroelastic half-space and the circular-arc valley are modeled as poroelastic medium based on Biot's dynamic theory. By introducing three potentials, the governing equations for Biot's theory are reduced to three Helmholtz equations. The series solutions of the Helmholtz equations are obtained by the wave function expansion method. Here, the large circle assumption is applied to simulate the boundary conditions at the half-space boundary. The stresses and pore pressures are obtained by using the boundary conditions and continuous conditions of the poroelastic half-space and the circular-arc alluvial valley. Numerical results show that the dynamic stresses concentration and pore pressures concentration are mainly relative to the wave shape of incidence, angle of incidence, dimensionless frequency of incident wave, stiffness and pore ratio of the poroelastic half-space and valley.