ORIGINAL PAPER The stability of road cut cliff face along SH-121: a case study P. K. Singh • A. B. Wasnik • Ashutosh Kainthola • M. Sazid • T. N. Singh Received: 21 August 2012 / Accepted: 4 March 2013 / Published online: 13 March 2013 Ó Springer Science+Business Media Dordrecht 2013 Abstract Rockfall is one of the major concerns along highways, settlements and forests around the globe. Amboli road cut hill is one such region which is highly vulnerable and suffers from recurrent rockfall mostly in the rainy season, which blocks the State Highway 121 for considerable period of time. The steep and highly jointed slope along the road makes the zone prone to failure due to rainwater action. This road experiences heavy traffic throughout the year as it is the only road connecting Goa to Satara and Kolhapur via Sawantwadi in Maharashtra State, India. Therefore, an attempt has been made in this study to understand the stability of the cliff face. A combination of field study and 2D computer simulation was performed to assess surface characteristics of the cliff face. Bounce height, translational kinetic energy, translational velocity and factor of safety for saturated con- dition have been estimated. The result of this study shows that the rock face is highly unstable taking into consideration the environmental condition and daily traffic. Proper preventive measures have also been suggested to arrest the movement of falling rocks before reaching the roads or valleys. It is a belief that if proper care is taken, then further uncertain rockfall hazards can be prevented. Keywords Rockfall  Finite element method  Bounce height  Coefficient of restitution 1 Introduction Slope instability is the most critical hazard in hilly areas. It includes lateral spread, topple, creep, rotational landslides, translational landslides and rockfall (Highland and Bobrowsky 2008). Rockfall is one of the most significant geological hazards in high mountainous region, but relatively fewer studies have been carried out to investigate them along highway road cuts, particularly in Amboli hills of Sahyadri region, Maharashtra, India. P. K. Singh (&)  A. B. Wasnik  A. Kainthola  M. Sazid  T. N. Singh Department of Earth Science, Indian Institute of Technology Bombay, Mumbai 400 076, Maharashtra, India e-mail: prakashks@iitb.ac.in 123 Nat Hazards (2013) 68:497–507 DOI 10.1007/s11069-013-0627-9