饱和土中排桩对入射S波隔离的三维分析

Three-dimensional isolation analysis of a row of pile in saturated soil from incident S waves

基于Biot两相饱和多孔介质理论,就饱和土体中排桩对入射S波的隔离效应进行了三维分析。使用坐标转换和Graf加法定理,将某一桩体附近的总波场构造为入射波和所有桩体的散射波之和,通过施加桩土界面处的边界条件,利用不同阶三角函数的线性无关性,得到了问题的解析解。数值算例对排桩后面的饱和土体的竖向位移振幅衰减进行了分析,探讨了入射波频率和桩土弹性模量比等参数对饱和土中排桩隔离效果的影响。与弹性土中的相应结果比较表明:频率较低时,饱和土中排桩的隔离效果和弹性土中较为接近;频率较高时,两者之间的差别有所增大。

Based on the Blot＇s two phase saturated porous medium theory, the effects of a row of pile on reducing the displacement amplitudes of soil excited by incidence of S waves were investigated. The wave field near certain pile was constructed as the sum of incident waves and scattering waves from all piles with the coordinate transformation and Graf addition theorems. By imposing continuity conditions at the soil-pile interfaces and taking account of the linear independence of trigonometric function, analytical solution of the problemns were obtained. Numerical calculations of vertical displacement amplitudes of saturated soil behind a row of piles were carried out. The results indicate that at relatively lower frequency, the isolation effectiveness of a row of piles embedded in saturated soil in vertical directions is similar to that of elastic soil conditions, while the isolation effectiveness in saturated soil is better than that of elastic soil conditions with increasing frequency.