3D scattering of obliquely incident SH waves by a cylindrical cavity in layered elastic half-space (Ⅱ): Numerical results and analysis

Surface displacements around a cylindrical cavity in layered elastic half-space under obliquely incident plane SH waves is studied by using the simplest model of single layer over bedrock. The result shows that there are distinct differences between the scattered waves by a cavity in layered half-space and those in homogeneous half-space. The layered half-space makes the surface displacement amplitudes around a cylindrical cavity much more complicated due to its resonant characteristics, both the bedrock-to-soil layer stiffness ratio and the thickness of the soil layer having important effect on the scattering. On the whole, surface displacement amplitudes increase with the increasing of bedrock-to-soil layer stiffness ratio, and the effects of soil layer on surface displacement amplitude decrease with the thickening of soil layer. The paper also presents a time-domain scattering solution on the basis of frequency-domain solutions, taking the Ricker waves as an example.