常规的滑坡稳定性评价方法仅考虑到滑动面基质吸力对强度的贡献,当降雨入渗深度小于滑面深度时,常规方法不能反映滑坡稳定性随降雨进行而降低这一现象。运用饱和土非饱和土统一抗剪强度理论,对滑坡土条受力分析进行了改进,推导了考虑土条侧边基质吸力变化的条分法,结合Iverson降雨入渗解析解,对降雨入渗过程中基质吸力变化导致边坡稳定性降低的机制进行了探讨。研究表明,土条侧面基质吸力提高了土体抗剪强度,它作为抗剪强度的一部分,通过条间作用力的形式提高土坡的稳定性,随着降雨入渗的进行,土条侧边基质吸力急剧下降,导致条间作用力下降,稳定系数降低。 Conventional methods for evaluating landslide stability consider only the contribution of the matrix suction of the sliding surface to the strength. When the infiltration depth is less than the depth of the sliding surface, the conventional method can not reflect the fact that the stability of the landslide decreases with the rainfall. Based on the unified shear strength theory of saturated soils unsaturated soil, the stress analysis of landslide soils was improved. The striping method which takes into account the change of soil matric suction is derived. Combined with Iverson rainfall infiltration analytical solution, The mechanism of the decrease of slope stability due to the change of substrate suction during the process was discussed. The results show that the lateral matrix suction of soil increases the shear strength of soil. As a part of shear strength, the stability of soil slope is improved by the force between the strips. With the infiltration of rainfall, Matrix suction decreased sharply, resulting in decreased force between the bars, the stability coefficient decreased.