Measures of slope stability in bonded soils governed by linear failure criterion with tensile strength cut-off

Abstract

The linear failure criterion with a tensile strength cut-off is increasingly applied to geotechnical stability problems in response to the uncertainty originating from the predicted tensile strength in soil. However, several attempts at slope stability analysis have employed classical failure mechanisms with geometrical and computational constraints. In the context of limit analysis, an advanced failure mechanism was utilized in this study for more accurate and comprehensive solutions of practical stability measures, including stability factors and factors of safety. This mechanism delivers lower stability factors and enables the estimation of the traditionally defined factor of safety, particularly in the tensile regime associated with the nonlinear part of the envelope. A technique that transforms the Hoek–Brown rock strength criterion into the equivalent linear failure criterion with a tensile strength cut-off is presented. The factors of safety based on the equivalent Mohr–Coulomb envelope subjected to the tension cut-off showed exceptional agreement with those based on the original Hoek–Brown equation, owing to the truncation of the overestimated strength in the low-stress regime.