Scattering of SV waves by a canyon in a fluid-saturated, poroelastic layered half-space, modeled using the indirect boundary element method
Scattering of SV waves by a canyon in a fluid-saturated, poroelastic layered half-space, modeled using the indirect boundary element method
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DOI：
10.1016/j.soildyn.2006.01.012
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发表时间：
2006-06
影响因子：
4
通讯作者：
Jianwen Liang;Hongbing You;V. W. Lee
中科院分区：
文献类型：
--
作者：
Jianwen Liang;Hongbing You;V. W. Lee
用间接边界元方法在频域内模拟了流体饱和的层状孔隙弹性半空间中峡谷对SV波的散射。计算自由场响应以确定峡谷表面的位移和应力，然后在自由场中对峡谷表面施加虚拟分布载荷以计算位移和应力的格林函数。根据边界条件确定虚拟分布荷载的幅值，并将自由场中的波浪引起的位移和虚拟分布荷载引起的位移相加得到解。讨论了流体饱和度、边界条件、孔隙度和土层对地表位移幅值和相移的影响，得出了一些有益的结论。结果表明，由于饱和和边界条件、不同的孔隙率或土层的存在，地表位移幅度可能非常不同，并且可以观察到大的相移。不排水饱和孔弹性介质的波长比排水饱和孔弹性介质的波长略长；排水饱和孔弹性介质的波长比干燥的孔弹性介质的波长长。随着孔隙率的增加，波长变长；层状半空间产生的波长比均匀半空间产生的波长更长。
The scattering of SV waves by a canyon in a fluid-saturated, poroelastic layered half-space is modeled using the indirect boundary element method in the frequency domain. The free-field responses are calculated to determine the displacements and stresses at the surface of the canyon, and fictitious distributed loads are then applied at the surface of the canyon in the free field to calculate the Green's functions for displacements and stresses. The amplitudes of the fictitious distributed loads are determined from the boundary conditions, and the displacements arising from the waves in the free field and from the fictitious distributed loads are summed to obtain the solution. The effects of fluid saturation, boundary conditions, porosity, and soil layers on the surface displacement amplitudes and phase shifts are discussed, and some useful conclusions are obtained. It is shown that the surface displacement amplitudes due to saturation and boundary conditions, different porosities, or the presence of a soil layer can be very dissimilar, and large phase shifts can be observed. The resulting wavelengths for an undrained saturated poroelastic medium are slightly longer than those for a drained saturated poroelastic medium; and are longer for a drained saturated poroelastic medium than those for a dry poroelastic medium. As porosity increases, the wavelengths become longer; and a layered half-space produces longer wavelengths than a homogeneous half-space.