考虑优势流作用的降雨入渗边坡可靠度分析

降雨诱发滑坡是世界上最普遍的地质灾害，而关于降雨入渗对边坡的可靠度分析，优势入渗的影响被长期忽视。使用Comsol Multiphysics对降雨条件下优势入渗做数值求解，利用无限边坡模型计算边坡安全系数；并应用改进Cholesky分解法生成空间相关随机场，使用蒙特卡洛方法分析降雨过程中边坡的可靠度。结合确定性与可靠度计算对比均质入渗与优势入渗在降雨过程中边坡安全性变化：（1）降雨强度较低时，优势入渗安全性较好，而降雨强度较高时，均质入渗更稳定；（2）均质入渗中参数空间变异性是边坡失稳破坏的关键因素，而优势入渗的边坡失稳则由湿润峰快速推进所导致；（3）针对优势入渗模型研究，发现基质域与优势域水力交换强度较大时边坡有更大概率失稳，而较小的水力交换强度可能影响边坡底部的失稳破坏。

Reliability analysis of slope under rainfall infiltration considering preferential flow model

Rainfall-induced landslides are the most common geological hazard in the world, and the effect of preferential flow infiltration has been neglected for a long time regarding the slope reliability analysis under rainfall infiltration. The preferential infiltration under rainfall conditions is solved numerically by Comsol Multiphysics, and the slope factor of safety is calculated using an infinite slope model. An improved Cholesky decomposition method is applied to generate spatially correlated random fields, and the slope reliability during rainfall is analyzed using the Monte Carlo method. Combining the deterministic and reliability results to compare the variation of slope factor of safety between the homogeneous infiltration and the preferential infiltration during rainfall, it can be found that: (1) the preferential infiltration model is safer when the rainfall intensity is low, while the homogeneous infiltration is more stable at higher rainfall intensity; (2) the spatial variability of infiltration parameters is the crucial factor of slope failure in homogeneous infiltration, while the slope instability of preferential infiltration is mainly caused by the rapid advance of the wetting front; (3) for the study of preferential infiltration model, the slope has a higher probability of failure when the hydraulic exchange intensity between the matrix domain and the preferential domain, while smaller hydraulic exchange intensity may affect the slope failure at the bottom.