Slope reliability analysis: some insights and guidance for practitioners

Several topics of concern have emerged in recent literature on probabilistic slope stability analysis, including the relative merits of probabilistic finite element methods, probabilistic limit equilibrium methods, Monte Carlo simulations, and first-order reliability method. Practitioners contemplating extending their long tradition of deterministic analysis into probabilistic analysis may be perplexed and even discouraged by the different views of the researchers of different probabilistic approaches. It is the purpose of this paper to contribute some personal insights and guidance on slope reliability analysis, and to provide a more balanced perspective of the different probabilistic slope stability approaches. Specifically, the following topics will be addressed, mainly in the context of soil and rock slopes: (i) Avoiding potential pitfalls in using Monte Carlo simulations, (ii) FORM reliability-based design, (iii) Probabilistic slope stability analysis accounting for spatial variation of soil properties, and (iv) System reliability analysis based on FORM and comparison with MC simulations.