摘要
为研究横观各向同性(TI)介质的凸起地形对平面qP-qSV波的散射问题,采用间接边界元法进行数值模拟,并且分别给出该问题在时域和频域内的解答。在求解过程中将计算模型分解为开口层状半空间域和闭合凸起域,同时将波场分解为自由波场和散射波场,自由波场可通过直接刚度法求得,散射波场由斜线荷载动力格林函数来模拟。频域结果表明,TI介质参数的改变导致了凸起和层状半空间动力特性的改变,进而导致了凸起与层状半空间动力相互作用机制的改变,使得不同TI介质参数对应的地表位移幅值显著不同。而时域结果表明,TI介质参数与波的传播方向均对qP波和qSV波的在凸起地形中的传播有着显著影响。另外,时域结果更为清晰地展示入射波、反射波和散射波的传播过程。
To investigate scattering of plane qP-qSV waves induced by a convex topography with the transversely isotropic(TI) medium, the indirect boundary element method(IBEM) is used for the numerical simulation and the solutions of the plane qP-qSV waves scattering problem in both the frequency and time domain are given, respectively. In the process of solving, the calculation model is divided into open layered half-space region and close hill region, and the wave field is decomposed into free wave field and scattered wave field, the first of which can be solved by the direct stiffness method, and the second can be simulated by the dynamic Green’s function by applying the fictitious inclined uniformly distributed load. The results in frequency domain show that the different TI media can change the dynamic characteristics of hill and layered half-space, and alter the dynamic interaction mechanism between hill and layered half-space, making the surface displacements significantly different. The results in time domain indicate that the parameters of the TI media and incident directions of plane waves have significant effects on the propagation of qP-qSV waves around the hill. In addition, time domain results clearly show the transmission process of incident, reflected and scattered waves.
作者
巴振宁
周旭
梁建文
BA Zhen-ning;ZHOU Xu;LIANG Jian-wen(Department of Civil Engineering,Tianjin University,Tianjin 300072,China;Key Laboratory of Coastal Structures in Civil Engineering and Safety of Ministry of Education,Tianjin 300072,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2019年第1期379-387,共9页
Rock and Soil Mechanics
基金
国家自然科学基金资助项目(No.51578373
No.51578372)~~
