容重增加法在边坡稳定性分析中的应用

通过逐步增加容重的方法使边坡达到极限平衡状态,基于D-P准则,采用关联流动法则,用非线性有限元法进行数值模拟.将坡顶水平位移随容重增加系数的变化关系曲线上位移陡然增大作为边破的破坏标准,用一个区间描述边坡稳定安全系数.该法无须事先对滑动面的位置和形状作出任何假定,能够考虑土体的材料非线性和几何非线性,有助于了解边坡的破坏机理.同时由于用一个区间描述边坡稳定安全系数,避免了数值计算中真实安全系数的丢失.算例分析表明,用容重增加法得到的安全系数与传统方法相近,并建议安全系数区间的长度取为0.03.

Application of gravity increase method in slope stability analysis

The limit equilibrium of slope was reached through increasing the gravity acceleration gradually,and it was numerically simulated using nonlinear finite element method,with the employment of associated flow rule and D-P criterion. The jump point in the curve relating the horizontal displacement of the slope top to the gravity increase factor was taken as the failure criterion of slope,and an interval was used to describe the safety factor of slope stability. The proposed approach does not need to make any assumptions about the shape or location of the failure surface in advance. It can consider the material non-linearity and geometric non-linearity of soil,and can properly simulate the destroy of slope,which is conducive to the comprehension of destroy principle of the slope. Meanwhile,using an interval to describe the safety factor of slope stability can avoid the loss of true safety factor in numerical calculation. Analysis on an example indicates that the safety factor obtained by using gravity increase method is close to that obtained by traditional methods,and the interval length of 0.03 for safety factor is suggested.