Rockfall hazard assessment along state highway in the eastern part of Mizoram, India

Rockfall is one of the most serious threats to human infrastructures, transportation routes, and villages located near steep slopes. In this study, two rockfall hazard rating systems, namely the Rockfall Hazard Rating System for Indian Rockmass and the Colorado Rockfall Risk Rating System, were used to analyze the areas susceptible to rockfall. These rating systems were correlated based on the data and results obtained. The study indicates that slopes 3 and 6 are highly vulnerable to rockfall, having cumulative scores greater than 500, indicating a high level of urgency and the need for rapid actions. Rocfall 4.0 software is used for numerical simulation, in which the slope geometry is depicted, such that the bouncing height and run-out distance, kinetic energy, and translational energy of rocks that fall from the investigated slopes are analyzed. The investigated slopes are in a critical state and require remedial measures in order to reduce their vulnerability to rockfall and traffic blockage. Rock-cut slopes can be sustained using a variety of approaches, including steel meshing on discontinuities, rock anchoring, and a toe wall with rock fencing. This study conducts a qualitative and quantitative assessment of rockfall risks along a significant corridor along the highway from Champhai to Zokhawthar hamlet.