基于剪切变形法考虑遮帘效应的群桩沉降计算

Settlement Calculation of Pile Groups Based on Shear Displacement Method Considering Restraining Effect

基于剪切变形法原理,导得了各基桩桩侧摩阻力在地基土中产生的位移场及应力场;并考虑了桩的遮帘效应,即各相邻基桩的存在对沉降的折减,得到了桩侧桩-土接触等效剪切弹簧刚度;同时,利用经深度修正后Boussinesq位移解,导得桩端-土接触等效弹簧刚度;在此基础上,分别求得了各基桩由自身桩顶荷载及其他邻桩引起的柔度系数,建立了基于剪切变形法的群桩沉降计算方法。算例结果表明,本文方法与实测值吻合较好。

Based on the shear displacement method,the displacement and stress fields in the surrounding soil of piles caused by shaft resistance were obtanined,and the restraining effect of piles was taken into account to calculate the piles＇ settlements,i.e.the reduction effect caused by the existence of the other adjacent piles,the equivalent stiffness coefficients of soil around each pile were developed.Besides,the Boussinesq solution considering the effect of pile embedded depths was used to derive the equivalent stiffness coefficients of soil under the pile tips.Then,flexibility coefficients of the displacement at the pile top induced by the load applied at itself and the other adjacent piles＇ loads were both gained.Thus,a method was built to calculate settlement of pile groups based on the shear displacement method.Settlement calculated by the present method agreed well with those measured results from field test.