Diffraction of plane P waves by a canyon of arbitrary shape in poroelastic half-space (Ⅱ

Diffraction of plane P waves by a canyon of arbitrary shape in poroelastic half-space (Ⅱ):

Numerical results and discussion

Jianwen Liang; Zhongxian Liu

【期刊名称】《《地震学报（英文版）》》 【年(卷),期】2009(022)003

【摘要】This paper investigates in detail the nature of diffraction of plane P waves around a canyon in poroelastic half-space, and studies the effects of incident frequency, drainage condition, porosity, etc, on the diffraction of waves. It is shown that the surface displacement amplitudes of the drained case are close to those of the undrained case, however, the surface displacement amplitudes of the dry case are very different from those of the saturated (either drained or undrained) cases. There are large phase shift between the dry case and the saturated cases, as well as slightly longer resultant wavelengths for the undrained case than those for the drained case and longer resultant wavelengths for the drained case than those for the dry case. For small porosity the surface displacement amplitudes for the saturated cases are almost identical to those for the dry case; while for large porosity, the effect of drainage condition becomes significant, and the surface displacement amplitudes for the undrained case are larger than those for the drained case. As the incident frequency increases, the effect of porosity