中文摘要：

目前有关土体参数空间变异性对边坡稳定性影响的研究没有考虑抗剪强度参数随深度变化的影响。为此，提出了考虑土体抗剪强度参数均值随深度变化的无限长边坡稳定性概率分析方法。采用Karhunen—Loeve展开建立了表征土体空间变异性的随机场模型。探讨了考虑土体抗剪强度参数空间变异性时边坡失效概率和最危险滑动面的变化规律。最后，以无限长边坡稳定性概率分析问题为例验证了所提方法的有效性。结果表明：土体抗剪强度参数的空间变异性对无限长边坡失效概率有明显的影响，边坡失效概率随土体抗剪强度参数相关距离的增加而减小。对于不排水黏性边坡来说，边坡不排水抗剪强度随深度变化越明显，边坡失效概率越小。边坡最危险滑动面大部分都位于边坡底部。对于摩擦／黏性边坡来说，随着边坡抗剪强度随深度变化的增强，边坡失效概率有先减后增的趋势。抗剪强度参数随深度变化不同趋势对最危险滑动面分布规律有明显的影响。不考虑抗剪强度参数均值随深度变化将会导致最危险滑动面最可能出现在边坡底部。

英文摘要：

The effect of the variation of soil shear strength parameters with depth on slope stability considering spatial variability of soil parameters has not been studied systematically. A probabilistic method is proposed for infinite slope stability analysis considering the variation of soil shear strength parameters with depth. First, the Karhunen-Loeve expansion is adopted to simulate the random field of spatially varying soils. Second, the effect of spatial variability of soil parameters on failure probability and critical slip surfaces is investigated. Finally, an infinite slope is presented to demonstrate the validity and capacity of the proposed method. The results indicate that the spatial variability of soil shear strength parameters has a significant influence on the failure probability of the infinite soil slope. The failure probability decreases with the increasing correlation length of soil shear strength parameters. For an undrained clay slope, a significant change in the undrained shear strength parameter varying with depth results in a smaller failure probability. Most of the critical slip surfaces will occur at the base of the slope. For a frictional/cohesive slope, the failure probability does not monotonically decrease with the increase of the variation of the soil shear strength parameters with depth. The trend of shear strength varying with depth has a significant influence on the critical slip surfaces. If the trend of shear strength varying with depth is ignored, it is most likely that the critical slip surfaces will occur at the base of the slope.