土坡稳定性分析新法——特殊对数螺线破裂面法

A New Method for Minimizing the Safety Factors in Slope Stability Analysis

本文应用变分法原理和极限平衡原理计算均质土坡的稳定系数.推导出破裂面形状应为一特殊的对数螺线。分析中引入了地震系数,用以研究地震条件下的上坡稳定性分析。根据所得破裂面形状,将作用于破裂土体上所有外力,对极点取力矩平衡,可得出不含有破裂面上法向应力函数的F_s计算式。用优化方法可以确定土坡稳定性系数及临界破裂面位置。从而避免了对破裂面形状和条间力的人为假定,提高了土坡稳定性分析结果的精度,大大简化了设计工作。本文的分析结果与文献试验结果吻合,且表明常规分析法所得稳定性系数偏低。

Based on the limit equilibrium principle and variational technique, a method for solving the safety factors in homogeneous slope stability analysis is presented. Earthquake coefficients are introduced in order to investigate slope stability under seismic conditions.It is revealed that the shape of the critical slip surface is a special logarithmic spiral. According to the critical slip surface and the moment equilibrium equation for the slope system, the method of optimization is employed to solve the safety factor in slope stability analysis. The normal stress distribution along the critical slip surface is not required to be considered in the analysis. The analysing results by this methyl are in agreement with the experimental results reported in Literature[6]. It is concluded that this method provides an effective means for practioners to facilitate their routine work in the calculation of minimum safety factors.