A COMPUTER PROGRAM FOR STABILITY ANALYSIS OF ROCK SLOPES FOR WEDGE FAILURE

Abstract

Rock slope failure frequently occurs in landslides, mining, road — cuts and tunneling projects. There are several features that affect the stability of rock slopes. Shear strength of the jointed rocks and rock masses is the governing factor for the stability of a slope. Joint analysis and stability computations were generally done through stereographic projections which is undoubtedly a time consuming process. Therefore, in this work a graphics package has been developed to obtain the stereographic projections of the joint planes. Program has also been developed to analyze the 3-D Wedge stability including the shear failure out of the different failure modes. The shear strength of the joint planes vary non-linearly with normal stress. To study the effect of this non-linearity, the program has been developed to assess the shear strength for a particular normal stress level by using the shear strength models proposed by Hoek and Brown (1980), IIT-D (Rao,1984;Ramamurthy,1986), Ladanyi and Archambault (1970), Patton (1966), Barton (1973) and Mohr-Coulomb (1953) model—the original and linear model for conceptualization of shear strength versus normal stress behavior. The shear strength obtained from these models corresponding to any normal stress gives the values of instantaneous cohesion `cf and friction angle `12if which are fitted into the Hoek and Bray (1971) method of rigorous analysis for determining the factor of safety of 3 dimensional wedge failure.