Sensitivity Analysis of Stability of Rockmass Slope Using Finite Element Limit Analysis

The design of various geotechnical engineering structures within/over a rockmass slope necessitates evaluating the stability. Despite numerous research, the problem of rockmass slopes still presents significant challenges to the designers. The numerical methods use the strength reduction method to evaluate the factor of safety (FoS) for a rock slope, where the stability analysis is performed by reducing the shear strength of rockmass in stages until the collapse occurs. In this study, the finite element limit analysis is performed for rockmass slope stability using Optum G2. The strength reduction method is used to evaluate the stability of rockmass slope using nonlinear Hoek–Brown failure model. The sensitivity analysis is performed to determine the effect of various parameters of rockmass on the FoS. The parameters considered are: geological strength index (GSI), material constant (mi), uniaxial compressive strength (σci), unit weight (γ), elasticity modulus (E), Poisson’s ratio (ν), slope height (H) and slope inclination (i). The results are represented in the form of spider plot and tornado plot to arrive at the sensitivity of each parameter considered in the study. Based on the study, it is found that the FoS of rockmass slope is dependent on GSI, mi, σci, γ, H and i and is independent of E and ν.