蒙特卡洛法与有限元相结合分析边坡稳定性

蒙特卡洛随机搜索法与弹塑性有限元法结合,求解边坡稳定问题。根据有限元分析的应力和孔隙水压力结果计算给定滑动面的安全系数。利用随机走步法不断更新试算滑动面,使其安全系数不断减小。通过比较一定数量的试算滑动面,确定边坡临界滑动面及其对应的最小安全系数。本方法通过随机搜索克服了大多数常规优化方法易陷入安全系数局部极小的问题。同时,本方法利用有限元法分析的应力和孔隙水压力结果,按有效应力法计算边坡安全系数,可分析施工过程中应力和孔隙水压力变化对边坡最小安全系数的影响。数值算例分析说明了所提出的确定边坡临界滑动面的方法的有效性和优越性。

SLOPE STABILITY ANALYSIS USING MONTE CARLO TECHNIQUE WITH FEM

The Monte Carlo method combined with the elastoplastic finite element method(FEM) is proposed to analyze the slope stability problems. The factor of safety is calculated with the aid of stress fields and the pore pressure field obtained from the finite element analysis. The trial slip surfaces are verified frequently by the random walking method and gradually tend to the critical slip surface. The global minimum factor of safety can be found by comparing the results of a number of trial slip surfaces. The proposed method can solve the problems of falling into local minima,which most regular optimization methods are prone to be,by the random search methods. On the other side,the proposed method can also consider the influence of the change of stress fields and pore pressure field on the minimum factor of safety by the finite element analysis. Numerical examples are analyzed to show the feasibility of the proposed method.