土体在长期的地质作用下，饱和渗透系数表现出天然的空间强变异性。为探究饱和渗透系数变异性对边坡破坏概率的影响。对Green-Ampt模型进行改进，确定了湿润峰深度、边坡安全系数与降雨历时的关系式，利用蒙特卡罗法建立了饱和渗透系数变异性分析框架，探讨了不同降雨强度作用下，饱和渗透系数变异性对边坡破坏概率的影响。结果表明:在降雨初期，饱和渗透系数变异系数越小，边坡表现出的失稳破坏概率越小；随着降雨历时增加，边坡破坏概率逐渐升高，且随着饱和渗透变异系数增大，边坡破坏概率反而越小。在临界降雨区间内，边坡破坏概率会骤然上升，且临界降雨区间随着降雨强度的增大而变得集中。

Under the long-term geological action, the saturated permeability coefficient of soil shows natural strong spatial variability. In order to explore the influence of saturated permeability coefficient variation on the failure probability of slope, the Green-Ampt model was improved and the relationship among the depth of wetting front, the safety factor of slope and the duration of rainfall was determined. Then, Monte Carlo method was used to establish the analysis framework of variation of saturated permeability coefficient, and the  influence of saturated permeability coefficient variation on the failure probability of slope under different rainfall intensity was discussed. The results show that in the initial stage of rainfall, the smaller of the coefficient of variation of saturated permeability is, the smaller the failure probability of the slope is. With the increase of rainfall duration, the failure probability of the slope increases gradually, and with the increase of the coefficient of variation of saturated permeability, the failure probability of the slope becomes smaller. In the critical rainfall range, the failure probability of slope instability rises suddenly, and the critical rainfall range becomes concentrated with the increase of rainfall intensity.