Rockfall Hazard Rating System along SH-72: a case study of Poladpur-Mahabaleshwar road (Western India), Maharashtra, India

Construction of railways, highways and roads around steep slopes is a challenging assignment and require special investigations by geologists and geotechnical engineers that help to identify critical slopes. Rockfall Hazard Rating System for India (RHRSI) is a modified scheme for Indian subcontinent and used to define overall stability of slopes in mountainous region or rock cut slopes. Once this rating system identifies critical zones, proper protection measures can be applied to prevent rockfalls. In this article, RHRSI is adopted to identify slopes, prone to rockfalls so that proper preventive measure can be proposed to mitigate loss. State Highway-72 (SH-72) connecting Poladpur to Mahabaleshwar, is an important transportation corridor supporting high vehicle traffic within the well-known tourist area is chosen for rockfall hazard rating. Field observations show that up to 15 km corridor from Mahabaleshwar town has frequent rockfall problems with two most rockfall locations situated at about 12 and 6 km from Mahabaleshwar town. Also, an attempt has been made to focus on risk-consequence analysis for rockfall locations. To this aim, the RHRSI is applied to SH-72 corridor on two locations which are identified as very prone to rockfall hazard.