Stability Analysis of Rainfall-Induced Landslide Using Numerical Modelling

Landslides triggered by rainfall are very frequent in India, especially in the Himalayan region. Despite various attempts, they are still occurring and causing heavy loss of life and civilization. Natural hazards are mostly inevitable, but the reduction in damage caused by them is always possible, through preventive measures. For the prevention of landslides, we need to adopt various mitigation techniques, but before that, an analysis of a slope’s stability is required to find a critical surface. In this study, a failed slope is considered in the Shimla district of Himachal Pradesh, and its stability before and after rainfalls of different intensities (throughout the year) was studied using numerical modelling. The repeated slope failure necessitates a numerical approach to comprehend the instability components because there have been no previous stability investigations of this slope failure. According to the results, the failure of this slope was primarily caused by rain during the monsoon. Before rainfall, the slope’s F.O.S. was more than 1, indicating that it was stable; but, following rainfall, it drops to 0.801, 0.578, and 0.576, respectively. This study further in the future can be used in designing a landslide early warning system.