ABSTRACT
The variability encountered in coal refuse geotechnical properties such as density, friction angle and cohesion, and the uncertainty of site conditions such as the phreatic surface can impact the assessment of the safety of a coal refuse disposal facility by slope stability analysis. A computerized probabilistic stability analysis methodology and its implementation to the reliability and risk assessment of an impoundment type disposal facility are described in this paper. It is shown that the uncertainty around the material and site factors directly reflect upon the estimate of factor of safety, and the probabilistic methods can assist the geotechnical engineer in accounting for variability and uncertainty through quantification of the risk involved in design.
