Diffraction of SH-waves by topographic features in a layered transversely isotropic half-space  

作　　者：Ba Zhenning Liang Jianwen Zhang Yanju 

机构地区：[1]Department of Civil Engineering, Tianjin University, Tianjin 300072, China [2]Key Laboratory of Coast Civil Structure Safety ( Tianjin University), Ministry of Education, Tianjin 300072, China

出　　处：《Earthquake Engineering and Engineering Vibration》2017年第1期11-22,共12页地震工程与工程振动（英文刊）

基　　金：National Natural Science Foundation of China under Grant Nos.51578373 and 51578372

摘　　要：Abstract： The scattering of plane SH-waves by topographic features in a layered transversely isotropic （TI） half-space is investigated by using an indirect boundary element method （IBEM）. Firstly, the anti-plane dynamic stiffness matrix of the layered TI half-space is established and the free fields are solved by using the direct stiffness method. Then, Green＇s functions are derived for uniformly distributed loads acting on an inclined line in a layered TI half-space and the scattered fields are constructed with the deduced Green＇s functions. Finally, the free fields are added to the scattered ones to obtain the global dynamic responses. The method is verified by comparing results with the published isotropic ones. Both the steady-state and transient dynamic responses are evaluated and discussed. Numerical results in the frequency domain show that surface motions for the TI media can be significantly different from those for the isotropic case, which are strongly dependent on the anisotropy property, incident angle and incident frequency. Results in the time domain show that the material anisotropy has important effects on the maximum duration and maximum amplitudes of the time histories.Abstract： The scattering of plane SH-waves by topographic features in a layered transversely isotropic （TI） half-space is investigated by using an indirect boundary element method （IBEM）. Firstly, the anti-plane dynamic stiffness matrix of the layered TI half-space is established and the free fields are solved by using the direct stiffness method. Then, Green＇s functions are derived for uniformly distributed loads acting on an inclined line in a layered TI half-space and the scattered fields are constructed with the deduced Green＇s functions. Finally, the free fields are added to the scattered ones to obtain the global dynamic responses. The method is verified by comparing results with the published isotropic ones. Both the steady-state and transient dynamic responses are evaluated and discussed. Numerical results in the frequency domain show that surface motions for the TI media can be significantly different from those for the isotropic case, which are strongly dependent on the anisotropy property, incident angle and incident frequency. Results in the time domain show that the material anisotropy has important effects on the maximum duration and maximum amplitudes of the time histories.

关 键 词：wave scattering and diffraction Green＇s function transversely isotropic SH-WAVES indirect boundaryelement method 

分 类 号：P315.9[天文地球—地震学]