Load Resistance Factor Design (LRFD) Approach for Reliability Based Seismic Design of Rock Slopes against Wedge Failures

摘要

The main objective of the paper is to summarize the developmental methodology and reliability-based LRFD guidelines for rock slopes against wedge failures. The wedge failure is one of the predominant rock slope failures observed in field situations when the discontinuity is in the form of intersecting joint planes. In this article, the Barton's theory has been used to arrive at analytical expressions for the factor of safety of the of the rock slopes against wedge failures. Design rules for rock slopes against wedge failure are developed using reliability methods, and expressed in Load and Resistance Factor Design (LRFD) format. First order reliability method (FORM) is used to estimate the probability of failure against sliding failure. The required load and resistance factors to maintain the stability against sliding mode of failure, targeting reliability indices from 2 to 5, are obtained for various values of coefficients of variation (COV) of residual friction angle of the rock, joint roughness coefficient (JRC) and joint compressive strength (JCS) and horizontal seismic acceleration coefficient.