Kinematic-based failure angle analysis for discontinuity-controlled rock slope instabilities: a case study of Ren Yi Peak Cluster in Fusong County, China

Failure angle, also called maximum safe slope angle, is an important design parameter for rock slope stability analysis and slope excavation. This study aims to scientifically acquire the failure angle of the jointed rock slope, and a method incorporating the kinematic analysis, Bayesian estimation and Monte Carlo simulation is proposed. The probabilistic kinematic analysis could consider the variety of discontinuity properties. The Bayesian estimation and Monte Carlo simulation could consider the varieties and uncertainties of the failure angle data. The proposed method is applied to a discontinuity-controlled rock slope located in the Fusong County, Jilin Province, China. Numerous widely scattered failure angle data is firstly obtained using the probabilistic kinematic analysis. Then the Bayesian estimation and Monte Carlo simulation are applied to determine the failure angle scientifically. The suggested failure angle of west, middle and east section of the studied slope are 65.67 degrees, 65.79 degrees and 64.76 degrees, respectively. The probabilities of kinematic instabilities are also obtained based on the failure angle data. In general, the studied slope is stable and suitable to develop projects.