基于随机场理论的强降雨条件下花岗岩残积土边坡的稳定性分析

Stability of Completely Decomposed Granite Slopes under Intense Rainfall Infiltration based on the Random Field Theory

花岗岩残积土具有明显的空间变异性,采用随机场方法研究了土体力学参数空间变异性对强降雨条件下花岗岩残积土边坡的稳定性的影响。采用湿润锋模型模拟强降雨条件下边坡中孔隙水压力分布,采用随机场模拟土体强度参数的空间变异性,采用强度折减法计算边坡的安全系数。研究表明:土体空间变异性可改变边坡的失效模式,随着土体空间相关距离的减少,滑体体积减小;考虑土体空间变异性后,边坡的失效概率对湿润锋的增加更为敏感,忽略土体内聚力和内摩擦角之间的负相关性会高估边坡的失效概率。

Completely decomposed granite（ CDG） is subjected to substantial amount of spatial variability. The purpose of this paper is to investigate the effect of spatial variability of the shear strength parameters of CDG on the stability of CDG slopes under intense rainfall infiltration. In the method used in this paper,the pore water pressure is modeled using the wetting font concept. The spatial variability of the strength parameters is modeled based on the random fields. The factor of safety of the slope is computed using the shear strength reduction method. It is found that the presence of spatial variability will change the failure modes of the slope. As the correlation distance reduces,the size of the sliding mass also tends to reduce. The stability of the soil will be more sensitive to the advancing of the wetting front. Ignoring the negative correlation between the cohesion and the friction angle will overestimate underestimate the failure probability of the slope.