Perched water zone occurs in the subsurface of the slope under heavy rainfall or above an impeding layer with relatively low permeability. It causes a decrease in the shear strength of the soil and the increase in the loading on the slope. As the most used method of estimate the slope stability, the limit equilibrium method considers the influence of rainfall infiltration on the slope stability by increasing the underground water table and decreasing the shear strength parameters on the slip surface. However, the contribution of perched pore water pressure is usually ignored. To incorporate the effect of perched water pressure into the stability analysis, the Bishop’s simplified method and Janbu’s simplified method are modified to perform stability analysis in the situation of circular and composite slip surfaces, respectively. The detailed methodology and numerical implement procedure are presented. Then, three examples are adopted to verify the proposed methods and to investigate the impact of the perched water zone on slope stability. The results show that the program developed in this study has considerable accuracy compared to commercial software. The pore water pressure in the perched water zone has important impacts on slope stability, especially when the depth of the perched water zone is greater than 4 m. Ignoring the perched pore water pressure in the slope stability analysis might overestimate the safety status of the slope.

在暴雨下或渗透率相对较低的阻挡层上方，斜坡水面会出现栖息水带。这会导致土壤的抗剪强度下降，并导致斜坡上的荷载增加。极限平衡法是估计边坡稳定性最常用的方法，它通过增加地下水位和减少滑动面的抗剪强度参数来考虑降雨入渗对边坡稳定性的影响。然而，通常忽略孔隙水压力的贡献。为了将栖息水压力的影响纳入稳定性分析，对Bishop的简化方法和Janbu的简化方法进行了修改，分别对圆形和复合滑动面情况进行了稳定性分析。介绍了详细的方法和数值实现程序。然后，通过三个例子来验证所提出的方法，并研究栖息水带对边坡稳定性的影响。结果表明，与商业软件相比，本研究开发的程序具有相当大的准确性。栖息水区的孔隙水压力对边坡的稳定性有重要影响，特别是当含水区的深度大于4 m时。在边坡稳定性分析中忽略高孔隙水压力可能会高估边坡的安全状态。结果表明，与商业软件相比，本研究开发的程序具有相当大的准确性。栖息水区的孔隙水压力对边坡的稳定性有重要影响，特别是当含水区的深度大于4 m时。在边坡稳定性分析中忽略高孔隙水压力可能会高估边坡的安全状态。结果表明，与商业软件相比，本研究开发的程序具有相当大的准确性。栖息水区的孔隙水压力对边坡的稳定性有重要影响，特别是当含水区的深度大于4 m时。在边坡稳定性分析中忽略高孔隙水压力可能会高估边坡的安全状态。