Case study of slope deterioration characteristics: Simbal Landslide, Salt Range, Pakistan

Abstract

For a slope structure, various deterioration phenomena progress in the slope over time, and failure may occur, which decreases the durability life and service life. The approach to slope stability due to deterioration is a different concept from the existing limit equilibrium analysis, which is limited to the physical characteristics and geometrical structure of the ground and groundwater. In this study, with a comparative review of various literatures related to the slope failure characteristics due to deterioration, the optimal formulas for shear strength reduction such as the exponential function, logarithmic function, and inverse hyperbolic function are found to be the best fits for the variations in strength reduction. In addition, a case study was performed for the Simbal Landslide, Salt Range, Pakistan, where the slope failure of some carbonate rock formations vulnerable to deterioration occurred. As a result, it was confirmed that landslide occurred because of the reduction in shear strength by deterioration, since the safety factor was approx. 1.0 when the slope failure occurred. Finally, as a quantitative approach to evaluate the slope stability due to deterioration, a methodology to evaluate the slope stability using the limit equilibrium analysis of the slope with optimal strength reduction curves was proposed.