一种考虑挡土墙变形的深基坑非线性土压力方法

基于深基坑墙后主动区土体应变状态模式的假定,采用反映墙后主动区土体应力-应变性状的卸荷应力路径试验确定的应力-应变关系,建立考虑挡土墙变形的非线性土压力的计算公式;就该公式的特点、参数的物理意义及其确定进行讨论;并对一简单算例进行计算,计算结果能反映土压力与挡墙位移的非线性关系以及土压力沿深度的非线性分布,得到墙后主动区土体达到主动极限状态所需的位移与深度的关系,计算结果比较满意.表明所建立的方法的合理性、可行性和适用性.

A nonlinear earth pressure method for deep excavation considering deformation of retaining wall

Based on the supposition for strain state mode of soil in active region behind wall, a nonlinear earth pressure computing formula considering retaining wall deformation is proposed, in which the unloading stress strain relationship obtained from unloading stress path laboratory tests simulating soil response in active region at back of wall is adopted. The characteristic of the formula, physical meaning of parameters and methods for obtaining them are discussed. A simple example is calculated using this nonlinear earth pressure method. The calculation results are quite satisfied, which include nonlinear relationship between earth pressure and deformation of wall, nonlinear distribution of earth pressure along depth, and deformation of wall for soil behind it reaching active limit state in different depths. It shows the rationality, feasibility and applicability of the nonlinear earth pressure method proposed in this paper.