多元复合地基压缩模量参变量变分原理解析解

Analytical solutions of composite modulus of multi-element composite foundation by parametric variational principle

选取双折线模型作为土的弹塑性本构模型 ,并在假设桩土变形协调的前提下 ,应用参变量变分原理求解多元复合地基的复合模量在弹性及塑性状态下的解析解。该解在桩间土为弹性状态时与目前工程中应用的面积加权法结果一致 ;当桩间土进入塑性状态时 ,与荷载及土的前后刚度比等因素有关。最后 ,采用大型有限元分析软件ANSYS对以上结论进行仿真验算。

Based on the bilinear elasto plastic model for soil and on the deformation consistency of pile and soil, the analytical solutions of composite modulus in a multi element composite foundation under both elastic and plastic conditions are obtained by applying parametric variational principle of minimum potential energy.The results show that the solution in elastic condition is in accord with that calculated by conventional area weighted average method,while the solution under plastic condition is related to factors including load and the ratio of soil stiffness under elastic condition to that under plastic condition.At last,all the solutions are verified by ANSYS. The method provide a new way to calculate the composite modulus of multi element composite foundation.