Probabilistic stability and sensitivity analysis of rock slope subjected to seismic loading

Abstract

Being located on the Pacific Ring of Fire, Indonesia has to cope with the constant risk of earthquakes which often trigger landslides in mountainous area, causing significant and even catastrophic damage. This paper presents probabilistic stability and sensitivity analysis of rock slope subjected to seismic loading based on Generalized Hoek-Brown failure criterion. Two approaches namely Limit Equilibrium Method (LEM) and Finite Element Method (FEM) were utilized using computer programs of Rocscience Slide and Phase2, respectively. The Generalized Hoek-Brown parameters such as, σci, GSI and mi were distributed normally with their coefficients of variation (COV) of 0.25, 0.125 and 0.1, respectively. The different seismic loadings expressed as Kh of 0.1, 0.3, and 0.5 were then subjected to the rock slopes and the probability of failure (Pf) was evaluated for each slope. Eventually, the results of Pf obtaining from LEM and FEM were compared and the most decisive parameter in slope stability were evaluated in sensitivity analysis. Based on the presented results of the analysis, the probability of failure (Pf) of the rock slopes which are subjected to the seismic loading generated by both FEM and LEM will decrease as the mean of GSI, σci, and mi increase. Moreover, the increment of the D value and seismic loading will induce the probability of failure (Pf) of the rock slopes which are generated by both FEM and LEM increase.