软土e-p曲线确定的简化方法及在非线性沉降计算中的应用

A simplified method for determining e-p curve of soft soil and its application to analyzing nonlinear settlement of foundation

首先假设软土的压缩曲线符合双曲线方程,并通过某工程一系列的数据进行验证,验证结果表明双曲线假定比较符合软土压缩曲线;由于双曲线方程参数相对较少,数据拟合确定比较简单易行,可对实际工程软土地基沉降进行简化计算并能满足工程的精度要求;同时还针对目前地质报告一般不提供详细的孔隙比-压缩应力(简称e-p)试验数据的情况,对e-p双曲线方程提出了一个只采用初始孔隙比e0、压缩模量Es来确定其参数的简化方法。在此基础上,基于e-p曲线确定邓肯-张模型的切线模量Et,采用分层总和法应用于软土地基的非线性沉降计算。对计算结果与实测数据进行比较分析表明,所提出的方法是切实可行的。

Firstly,an assumption that the compressibility curve of soft soil fits in with the hyperbolic equation is adopted;and it is validated by a series of data in a certain project.Since there are only a few parameters of hyperbolic equation,it is simple and feasible to use data fitting.Thus a simplified calculation can be introduced to the practical calculation of soft soil foundation and meets the accuracy requirement of a project.And then under the circumstance of not having adequate e-p experimental data in a geological report,a simplified approach is put forward to determine parameters of e-p hyperbolic equation with initial void ratio e0 and compressive modulus Es.Finally,based on the above-mentioned method of e-p curve,we acquire tangential modulus（Et） of Duncan-Chang model and with the Layer-wise Summation method（LST） apply it to the nonlinear settlement calculation of soft soil foundation.By comparing the tested settlements with the calculated ones,it is shown that the simplified method is capable and practicable.