Slope Stability Analysis of the Qalandarabad Landslide

Abstract

The current study investigates the slope failure at Qalandarabad, Khyber Pakhtunkhwa, Pakistan. The factor of safety (FOS) of the slope is determined using limit equilibrium method (LEM) with the assumption of Morgenstern and Price (MP), ordinary (O), Janbu (J) and Bishop (B) methods in Slope/W software. The analyses are assumed for dry and fully saturated field drainage condition. The values of factor of safety (FOS) for four distinct locations range from 0.344 to 0.383 for gravity loading, 0.287 to 0.332 for seismic loading. The values of FOS indicate relatively unstable slopes. Therefore, slope is strengthened with the strengthening technique (e.g., retaining wall) to increase the FOS values to 1.531 to 1.690 for gravity loading and 1.293 to 1.482 for seismic loading. In addition, the results show that FOS increases with increase in cohesion and internal friction angle, however, increase in the unit weight and overburden pressure result in decrease in FOS.