刚性空心管桩屏障对P波和SH波的隔离效果研究

采用波函数展开法和Graf加法定理,根据桩-土界面处总应力和扭矩平衡的边界条件,得到单排非连续刚性空心管桩屏障对入射平面P波和SH波散射系数的理论解。引入无量纲位移和透射系数等概念,绘制了不同壁厚的刚性空心管桩屏障后的无量纲位移等值线、透射系数随管桩间距的变化曲线以及不同数量的管桩组成的屏障后的无量纲位移变化曲线等图件,通过进一步的分析得出单排非连续刚性空心管桩屏障的隔振效果随着管桩间距和壁厚的减小而提高、最佳隔离区域随着管桩数量的增多而增大等重要结论,为非连续刚性屏障的隔振设计提供了理论依据。

STUDY ON THE EFFECT OF BARRIER OF A ROW OF RIGID HOLLOW PIPE PILES FOR THE ISOLATION OF P AND SH WAVES

The expansion method of wave functions and Graf’s addition theorem are adopted, the equilibrium conditions of the total stresses and torques at the boundaries of rigid piles and soils are considered, and theoretical solutions of scattering coefficients for incident plane P wave and SH wave by the barrier composed of a row of rigid hollow pipe piles are obtained. The concepts of normalized displacements and transmissibility index are introduced. The contours of the normalized displacements behind the barrier of rigid hollow pipe piles with different wall thicknesses, the curves of transmissibility index changing with the distance between the piles and the curves of the normalized displacements changing with the number of piles are drawn. Then some important conclusions are obtained. For example, the vibration isolation effect of the barrier increases as the separations or the wall thicknesses of the rigid hollow pipe piles decrease, and the area of best vibration isolation effect increases as the number of piles increases, which provides a theoretical basis for the design of discontinuous barrier for vibration isolation.