边坡稳定性分析的Sarma模式及其可靠度计算方法

Sarma model for slope stability analysis and its reliability degree calculation method

推导了边坡Sarma力学模式稳定性分析的有关公式,揭示了其稳定性系数是隐式函数的特点,研究了该隐式稳定性系数的迭代计算方法。针对Sarma模式和经典响应面法的特点,将响应面中的有限元数值模拟以Sarma模式中隐含稳定性系数的迭代方法代替,而隐含稳定性系数迭代计算过程中随机变量的抽样则遵从响应面中的规则,将传统的响应面思路与Sarma模式结合起来,形成了一种新的边坡稳定可靠性响应面分析方法。最后采用此方法分析了某一边坡工程的稳定可靠性,并把分析过程与结果与蒙特卡洛模拟法计算结果进行对照,表明该方法计算效率较高,原理简单,精度满足要求。

The formula for analyzing the slope stability based on the Sarma model was deduced and the iteration method for determining the implicit stability coefficient was studied. The finite element numerical simulation in classical response surface method was substituted by iterative calculation of implicit stability coefficient of slope in Sarma model. Sampling rule of random variables in iterative calculation method of implicit stability coefficient obeys sampling rules of response surface method. An idea of classical response surface method was combined with Sarma model and a new response surface method of slope stability reliability degree analysis was established. The new method was applied to analyze the stability of a slope and the procedure and calculation result were compared with those of Monte-Carlo method. It is found that the calculation efficiency of the proposed method is much higher and the accuracy of calculation result is acceptable.