Landslide Risk Evaluation of Road-Cut Slopes Along NH-707A in Mussoorie, Uttarakhand, India Using Conventional Rock Mass Classification System

One of the major issues in the road-cut slopes of the Himalayan region is the widening of roads and construction operations which are increasing nowadays due to rapid urbanization and increasing demands of different geoengineering projects. The stability these slopes gets more affected during the occurrence of rainfall and seismic activity resulting to Landslide. This paper presents the risk evaluation of the road-cut slopes in the lesser Himalayas. The analysis has been performed on five road-cut slopes (S1, S2, S3, S4, S5) along NH-707A near Mussoorie, Uttarakhand, India. For evaluating the vulnerability of these slopes, rock mass classification schemes such as Landslide Susceptibility Score (LSS), Landslide hazard evaluation factor (LHEF), Rock Mass Rating (RMR) and Slope Mass Rating (SMR) are used. These methods are based on certain parameters which are obtained from field surveys and laboratory experiments. The results from LSS shows that all the five slopes are falling under the category of moderate susceptibility. In the case of LHEF, S2 and S4 are coming in high hazard zone and rest of the slopes (S1, S3, S5) in moderate hazard zone. Similarly, RMR and SMR rating system are categorizing S1 and S3 under stable slope class state and remaining slopes (S2, S4, S5) in partially stable state.