An Insight into Slope Stability Using Strength Reduction Technique

In Shear strength reduction (SSR) technique, the factor of safety (FOS) is defined as the ratio of the material's actual shear strength to the minimum shear strength required to prevent failure. Failure surface is found automatically through the zones within the material, where applied shear stresses cross the shear strength of the material. In this paper, a review of the technique is discussed in reference to FLAC. A brief background of the approach together with detailed procedure is presented.An attempt is made to exhibit the shear strength dependency of the strain. As stability of the slope is a function of the shear strength, the development of failure strain reflects the potential failure zone of slope. The shear strain developed in the slope increases with reduction in the shear strength and is reflected in the analysis. The concept of failure ratio (R-f) is incorporated in shear strength reduction technique and is demonstrated. Relationships between the critical shear strength reduction ratio and the safety factor are examined.