INTEGRATING SOIL PROPERTY VARIABILITY IN SENSITIVITY AND PROBABILISTIC ANALYSIS OF UNSATURATED SLOPE: A CASE STUDY

Abstract

Slope failure poses a significant challenge in geotechnical engineering, with the spatial variability of soil properties emerging as a crucial factor influencing slope stability. This research paper introduces a method that integrates soil property variability into sensitivity and probabilistic analyses of slope failure. By means of sensitivity analysis, we identify the most influential soil properties that affect slope stability, while probabilistic analysis allows us to quantify the probability of slope failure. To exemplify this approach, we conducted a case study in Sapa, Vietnam. In this study, TRIGRS was employed to estimate the changes in groundwater induced by rainfall within the slope. Additionally, SLOPE/W, a widely used commercial computer program that leverages Monte Carlo simulation as its underlying methodology to estimate the probability of slope failure, was utilized in the next step. Our study underscores the significance of employing accurate and representative soil properties in slope stability analysis. By comparing the outcomes obtained through a deterministic approach with those derived from a probabilistic approach, we demonstrate that the latter provides a more realistic estimate of the probability of slope failure. Our findings unequivocally establish that soil property variability exerts a substantial impact on slope stability. Consequently, it is imperative to incorporate this variability into the analysis to effectively evaluate the risk of slope failure.