不同随机场模拟对斜坡失稳风险评估结果的影响

使用不确定性分析方法定量评估斜坡失稳风险结果受到学者们的日益重视。针对现有斜坡失稳风险评估中仅采用平稳随机场模拟土体抗剪强度参数分布特征的问题，以一不排水饱和粘土斜坡为例，结合有限元极限分析、强度折减法和蒙特卡洛模拟，讨论了使用非平稳随机场模型和平稳随机场模型模拟土体抗剪强度参数对计算斜坡失稳风险评估结果的影响。结果表明：使用传统的平稳随机场计算斜坡失稳风险的方法会高估斜坡失稳风险，使工程造价增加；安全系数高的斜坡滑面不一定是浅层滑面；斜坡竖直相关距离对采用非平稳随机场计算其失稳风险结果影响较小，而斜坡竖直相关距离对采用平稳随机场计算其失稳风险结果影响显著；斜坡竖直相关距离对滑动面位置和形状的影响较弱。

Influence of different random field simulation on the results of slope failure risk assessment

More and more attention has been paid to the results of quantitative assessment of slope failure risk by using uncertainty analysis method. In view of the problem that only stationary random field was used to simulate the distribution characteristics of shear strength parameters in the existing risk assessment of slope failure, in this paper, taking an undrained saturated clay slope as an example, combined with finite element limit analysis, strength reduction method and Monte Carlo simulation, the influence of shear strength parameters of soil simulated by non-stationary random field model and stable random field model on Calculation of slope instability risk assessment results were discussed.The results show that the traditional method of calculating the risk of slope failure by using stationary random field will overestimate the risk of slope failure, which will increase the project cost.The slip surface of slope with high safety factor is not necessarily a shallow slip surface. The vertical correlation distance of slope has little influence on the calculation of its failure risk by using non-stationary random field, while the vertical correlation distance of slope has significant influence on the calculation of its failure risk by using stationary random field. The influence of vertical correlation distance on position and shape of sliding surface is weak.The research results can provide guidance for the accurate evaluation of slope stability.