Probabilistic model of unsaturated slope stability considering the uncertainties of soil-water characteristic curve

Many soil slopes are unsaturated and their failure can be a major cause of damage to structures. Apart from soil properties, the Soil-Water Characteristic Curve (SWCC) is the backbone of any unsaturated slope analysis. Uncertainties of these effective parameters of unsaturated slopes make the probabilistic analysis more realistic, rather than deterministic. In this research, the stochastic analysis of unsaturated slope stability is carried out based on the simplified Bishop's method. The stochastic parameters are the input parameters of SWCC, in addition to effective internal angle of friction, effective cohesion, and unit weight of soil. Based on the collected results from hundreds of stochastic analyses, the probability of failure is presented as a three-dimensional surface. Finally, the probabilistic model is developed to model this surface and evaluate the probability of failure as a function of safety factor and its correlation of variation. (C) 2018 Sharif University of Technology. All rights reserved.