平面SV波入射下弹性半空间中三维球形洞室的动力响应

Dynamic response of 3D spherical cavity in elastic half-space under plane SV waves

采用一种间接边界积分方程法求解了平面SV波入射下弹性半空间中三维洞室的动力响应问题。通过与已有结果的比较,验证了方法的计算精度。在此基础上,以半空间中圆球形洞室为例,对地表位移响应和洞周动应力集中特征进行了详尽的参数分析,并与二维模型进行了比较。研究表明:二维和三维模型对平面波的动力响应在平面内存在一定的相似性,但在波型转换上存在显著差别,尤其体现在响应峰值及空间分布特征上,并且随着频率的升高,空间分布差异愈加明显;在出平面方向,三维洞室周围存在着显著的波散射效应,而二维模型难以描述这种出平面波型转换现象。

Dynamic response of a three-dimensional （3D） spherical cavity in elastic half-space under incident plane SV waves is investigated by using the indirect boundary integral equation method （IBIEM）. The accuracy of the method is verified through comparison with the solutions in literatures. Taking a spherical cavity as an example, both the dynamic surface displacement and the dynamic stress concentration around the cavity in a homogeneous half-space are solved and analyzed through parametric studies, and the comparison between 3D and 2D results is implemented. It is shown that the dynamic responses around 2D and 3D cavity are similar in general, but there are still evident differences in wave-pattern conversion, especially for their peak values and spatial distributions, and the differences of the spatial distribution are more obvious when the incident frequency increases. In the anti-plane direction, the scattering effect is significant in 3D case, but it is difficult to be described in 2D case.