基于剪应变判据和修正重度增加法的边坡稳定分析

Slope Stability Analysis Based on Shear Strain Criterion and Modified Weight Increment Method

基于强度折减法,以膨胀土边坡为例,分析了其危险滑面剪应变随强度折减系数的变化特征,将其划分为三个阶段:弹性变形阶段、塑性平衡阶段和无限塑性流动阶段。基于此提出两种求解边坡稳定系数的方法:剪应变的突变性和临界剪应变的方法,并在案例中验证了两者的可行性。同时提出了重度增加法的修正公式,并结合临界剪应变的方法,求解出修正后的安全系数,结果与强度折减法符合较好,克服了传统重度增加法精度差的问题,也验证了修正公式和临界剪应变法的可行性。

Based on the strength reduction method and taking the expansive soil slope as an example,the variation characteristics of the shear strain on the dangerous sliding surface with the strength reduction coefficient were analyzed and divided into three stages:elastic deformation stage,plastic equilibrium stage and infinite plastic flow stage.Based on these three stages,two methods were proposed to solve the stability coefficient of the slope:the abrupt change of the shear strain and the method of the critical shear strain and the feasibility of the two methods were verified in the case.At the same time,the modified formula of the heavy weight increasing method was put forward,and the modified safety coefficient was obtained by combining with the method of critical shear strain.The results are in good agreement with the strength reduction method,which overcomes the problem of poor accuracy of the traditional method of increasing the weight,and verifies the feasibility of the modified formula and the critical shear strain method.