Deterministic and Probabilistic Slope Stability Applied to a Landfill Slope

This paper, for the first time, presents a practical case where the probabilistic slope stability approach has successfully been used to evaluate a Municipal Solid Waste (MSW) landfill slope that failed due to a combination of steeper slopes and high liquid levels. The results of this evaluation will benefit practicing landfill engineers in applying probabilistic theory to landfill design and operational practice. Conclusions are presented based on deterministic factors of safety (FS), reliability indices (β), and probability of failure (P_f) values. The β and P_f values are compared with the US Corps of Engineers' recommended values for slope performance. Results show that probabilistic methods can capture the behavior of highly heterogeneous slopes (such as MSW slopes) and can be used by landfill engineers to make design, construction, and operational decisions.