Reliability Analysis of Slope Stability of Embankment Dams Considering Spatial Variability of Hydraulic Model Parameters

Only the spatial variability of soil shear strength parameters is taken into account in most slope reliability analysis of embankment dams, whereas the spatial variation of unsaturated hydraulic model parameters is ignored.This paper develops a non-intrusive stochastic analysis method for evaluation of slope reliability of embankment dams, wherein the influence of the spatial variability of hydraulic model parameters on the slope reliability of embankment dam is incorporated.The phenomenon that the probability of slope failure decreases with increasing the coefficient of variation (COV) of hydraulic model parameter n is explained.The results indicate that the developed method has much higher computational efficiency in comparison with the direct Monte-Carlo simulation method.The probability of slope failure is positively correlated with the COVs of the cohesion, friction angle and saturated hydraulic conductivity.The variability of the cohesion affects the slope reliability the most, while that of the saturated hydraulic conductivity has the least effect on the slope reliability.In addition, the probability of slope failure almost keeps unchanged as the COV of hydraulic model parameter a varies.It is also interesting to note that the probability of slope failure decreases as the COV of hydraulic model parameter n increases.This is because more realization values of n that are close to the lower bound of 1.05 can be generated when a larger COV of n is used.As a result, a smaller hydraulic conductivity and a lower flow rate that passes through the dam body are induced.Consequently, the safer slope of embankment dam is achieved. © 2021, The Editorial Board of Journal of Basic Science and Engineering. All right reserved.