Existing reliability analyses of embankment slopes usually considered the spatial variabilities of shear strength parameters and saturated hydraulic conductivity separately. Additionally, the variability in the soil–water characteristic curve (SWCC) was ignored. A non-intrusive approach is proposed for reliability analyses of unsaturated embankment slopes under four different cases on a steady-state seepage analysis. The spatial variabilities of hydraulic parameters (including fitting parameters, a and n, of SWCC and saturated hydraulic conductivity) and shear strength parameters are accounted for simultaneously. To illustrate the proposed approach, a hypothetical embankment under unsaturated seepage is investigated. The soil parameters of the embankment and foundation are modeled as lognormal random fields and lognormal random variables, respectively, to take into account the inherent uncertainties. Parametric sensitivity studies are then performed to account explicitly for the influence of the spatial variation of hydraulic parameters on the reliability of embankment slope stability. The proposed approach can act as a practical and rigorous tool for estimating the reliability of embankment slopes with small levels of probability of failure (i.e., 10−4–10−3). An interesting finding that the probability of failure of the unsaturated embankment slope decreases with the variability of the fitting parameter n of SWCC is observed and explained.

中文翻译：

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考虑土壤水力和抗剪强度参数空间变化的非饱和路堤边坡非侵入式可靠度分析

现有的路堤边坡可靠性分析通常分别考虑抗剪强度参数和饱和导水率的空间变异性。此外，土壤-水特征曲线（SWCC）的变异性被忽略。在稳态渗流分析的四种不同情况下，提出了一种非侵入式方法，用于非饱和路堤边坡的可靠性分析。同时考虑了水力参数（包括 SWCC 和饱和导水率的拟合参数 a 和 n）和抗剪强度参数的空间变异性。为了说明所提出的方法，研究了一个假设的非饱和渗流路堤。路堤和地基的土壤参数被建模为对数正态随机场和对数正态随机变量，分别考虑固有的不确定性。然后进行参数敏感性研究，以明确说明水力参数空间变化对路堤边坡稳定性可靠性的影响。所提出的方法可以作为一种实用且严格的工具，用于估计具有小故障概率（即 10-4-10-3）的路堤边坡的可靠性。观察并解释了一个有趣的发现，即非饱和路堤边坡的破坏概率随着 SWCC 拟合参数 n 的变化而降低。所提出的方法可以作为一种实用且严格的工具，用于估计具有小故障概率（即 10-4-10-3）的路堤边坡的可靠性。观察并解释了一个有趣的发现，即非饱和路堤边坡的破坏概率随着 SWCC 拟合参数 n 的变化而降低。所提出的方法可以作为一种实用且严格的工具，用于估计具有小故障概率（即 10-4-10-3）的路堤边坡的可靠性。观察并解释了一个有趣的发现，即非饱和路堤边坡的破坏概率随着 SWCC 拟合参数 n 的变化而降低。