Abstract
A program 3DSTAB combining slope stability analysis and reliability analysis is developed and validated. In this program, the limit equilibrium method is utilized to calculate safety factors of critical slip surfaces. The first-order reliability method is used to compute reliability indexes corresponding to critical probabilistic surfaces. When derivatives of the performance function are calculated by finite difference method, the previous iteration’s critical slip surface is saved and used. This sequential approximation strategy notably improves efficiency. Using this program, the stability reliability analyses of concrete faced rockfill dams and earth core rockfill dams with different heights and different slope ratios are performed. The results show that both safety factors and reliability indexes decrease as the dam’s slope increases at a constant height and as the dam’s height increases at a constant slope. They decrease dramatically as the dam height increases from 100 m to 200 m while they decrease slowly once the dam height exceeds 250 m, which deserves attention. Additionally, both safety factors and reliability indexes of the upstream slope of earth core rockfill dams are higher than that of the downstream slope. Thus, the downstream slope stability is the key failure mode for earth core rockfill dams.
Highlights
Rockfill dams are commonly used geotechnical infrastructures for water management
To calculate the safety factor of the slope stability, mean values are assigned to the variables and the particle swarm optimization (PSO) method is applied to search the critical slip surface, which is referred to as the critical deterministic surface (Li et al 2007 [27])
The critical slip surface is searched, and the corresponding safety factor is determined for every realization of the random variables in every iteration
Summary
Rockfill dams are commonly used geotechnical infrastructures for water management. One of the critical aspects of rockfill dam design is stability analysis, that is, the computation of safety factors (Chen and Morgenstern 1983 [1]; Janbu 1973 [2]). Whether LEM or SRM is used, the stability analysis of rockfill dams is a time-consuming process and the calculated safety factor is an implicit function of basic variables, such as materials’ shear strength parameters and dry bulk density. The surrogate performance function from the RSM may cause a deviation from the exact model (Luo et al 2012 [10]) When no such surrogate performance function is used, most previous reports have utilized the mean value first-order second-moment (FOSM, Hassan and Wolff 1999 [7]) method or its extension, the point-estimate method (Rosenblueth 1975 [11]), to calculate the approximate reliability index of slope stability. Rockfill dams with different heights over 100 m and different slope ratios are analyzed to study the relationships of the safety factors and reliability indices to the dam height and dam slope ratio parameter
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
