Slope Stability Analysis Consid­ering Local Factors of Safety Using Non-vertical Slices within the Limit Equilibrium framework

Abstract

A method for slope stability analysis considering local factor of safety is pro­posed based on a technique of non-vertical slices ,vithin the limit equilibriumf amework, ·which wonk! give an estimate of the stability of a slope that failsprogressively. To accommodate the non-uniform shear stress distribution, the local factors of safety are calculated by defining variable factor of safety instead of conventional single value safety factor along a shear surface. Simplifying as­sumptions about the inter-slice forces and their points of action made this method determinate. In the analysis, the acting points of inter-slice forces and forces at slice base are set to he varied for the complete converged solnti,on .. Strnin softening using Law and Lumb (1978) approach of peak and residual strength, is also included in the analysis. Two loading conditions called as In­stantaneous Load-ing Cond·it-ion(ILC) and Grndual Loading Condition(GLC), a.re introthtced for treating the locally failed zones. An overall factor of safety is introduced for the ultimate stability of a slope. The appropriate boundary conditions are satisfied successfully. A rigorous optimization scheme is intro­duced in order to find out the equilibrium conditions using simplex method. The proposed method can handles both the approaches of non-vertical and vertical slices as well.-------