沉桩挤土效应分析

Pile-sinking induced soil squeezing effect

将平面圆孔扩张理论推广到空间轴对称条件,改进了沉桩引起的位移解析解;考虑土体的弹塑性和挤土引起的土体性质的变化,利用有限元法对沉桩进行了分析计算;对沉桩进行了离心模型试验.研究结果表明,沉桩挤土效应的求解应考虑空间轴对称条件,沉桩引起的挤土效应将影响桩基础的计算结果,解析解较有限元结果更接近试验值.

The cavity expansion theory used for plane problems is extended to the spatial axisymmetric condition to improve the analytical solution of soil displacement induced by pilesinking. The FEM is used for calculation of the soil displacement with consideration of the elastoplastic behavior of soil and variation of soil characteristics induced by soil squeezing, and centrifugal model tests are performed for pilesinking. Research shows that in solution of pipesinking induced soil squeezing effect, the spatial axisymmetric condition should be considered, that the soil squeezing effect will influence the calculated results of pile foundations, and that the analytical solution is closer to the data measured from centrifugal model tests than that calculated with the FEM.