饱和地基中多排孔远场被动隔振分析

针对实际工程中单排孔隔振效果差的问题，采用饱和土半解析边界元法研究分析了多排孔的远场被动隔振效果。根据多排孔内表面的边界条件，推导得到了多排孔对入射Rayleigh波散射的三维边界元方程，编制了计算程序，对多排孔的远场被动隔振问题进行了详细的参数分析。结果表明：相对于单排孔，多排孔能够对入射Rayleigh波进行有效的隔振，且多排孔的排列方式对隔振效果影响较小；多排孔的排数以两排为宜，排间净距取排孔直径时隔振效果最优；多排孔每排孔的数量对隔振效果和有效屏蔽区域的面积影响较大，建议根据有效屏蔽区域来确定排孔孔数，且每排孔孔数不宜少于6个。此外，与单排孔隔振类似，排孔的深度宜取1倍Rayleigh 波波长；随着孔间净距的增加，多排孔隔振效果逐渐劣化，多排孔不再呈一个整体对Rayleigh波进行隔振。
Abstract：Aiming at the problem of single row hole vibration isolation effect being poor, the far field of multi-row holes passive vibration isolation effect in homogeneous saturated soil was studied with the semi-analytical boundary element method (BEM) combined with the basic solution of the thin layered method (TLM).According to the boundary conditions of multi-row holes’ internal surface, a 3D boundary element model for multi-row holes scattering incident Rayleigh waves was derived and the corresponding computation programming was made.The detailed parametric analysis for the far field of multi-row holes passive vibration isolation problem was performed.The results showed that multi-row holes can effectively isolate ground vibrations due to incident Rayleigh waves, and the arrangement of holes has a smaller effect on the vibration isolation effect; two-row holes are preferred, and the vibration isolation effect is the best when the net spacing between two successive rows of holes is taken as a hole diameter; the number of holes in a row has a larger effect on the vibration isolation effect and the effective isolation area; the number of holes in a row should be decided according to the needed isolation area, and it should be large than 6; the hole depth is taken as the wavelength of Rayleigh waves; with increase in the net spacing between two successive holes, the vibration isolation effect of multi-row holes gradually becomes poorer, multi-row holes no longer isolate the ground vibration due to incident Rayleigh waves as a whole.