基于滑面正应力假设的土压力计算方法

Method for Computation of Earth Pressure Based on Normal Stress Assumption

基于滑面正应力假设,提出一种新的极限平衡方法计算挡土结构土压力。首先假定滑裂面上正应力分布为含2个待定参数的三次拉格朗日插值函数;推导出包含主动土压力的水平力、垂直力和绕挡土墙顶点旋转的力矩平衡方程;然后采用优化方法确定最危险滑裂面位置及对应的最大主动土压力。与传统土压力计算方法相比,作者提出的方法可以给出精度较高的土压力分布,且可分析土压力作用点位置对土压力值的影响,其土压力计算方法可应用于工程上。

In this paper, a new limit equilibrium method is proposed for calculating earth pressures acting upon retaining walls based on assumptions regarding the normal stresses over the potential slip surface. Firstly, the normal stress distribution over the slip surface is assumed to be represented by a Lagrangian interpolation function involving two unknowns. Secondly, the horizontal and vertical force and moment equilibrium equations for the sliding body are derived incorporating the active lateral force. In the end, the most dangerous failure surface and maximum active earth pressure can be readily determined by optimization procedure. Com- pared to conventional methods of computing earth pressure, using the present method can yield earth pressure distribution of relatively higher precision and can analyze the relationship between the active earth pressure and the location of the application point. Thus, this new method can be applied to practical engineering.