The scattering of plane P₁ wave by a 3-D sedimentary basin in a fluid-saturated poroelastic half-space using IBEM

The indirect boundary element method (IBEM) is applied to investigate the scattering of elastic waves around a 3-D sedimentary basin filled with fluid-saturated poroelastic medium. Based on this method, the free field and scattered field can be solved according to the boundary conditions. And the numerical accuracy has been verified. The effects of parameters on elastic wave scattering are studied, such as boundary condition, incident frequency, incident angle and porosity of medium. Numerical results illustrate that the amplification effect of surface displacement near poroelastic sedimentary basin is notable. In addition, for the case of large porosity the drainage condition has a significant impact on the response amplitude. Due to the fluid exchange at the interface under the drained condition, the displacement amplitude can be much larger than that under the undrained condition in present study. The study can provide a theoretical basis for the anti-seismic design of engineering structures located in sedimentary basin.