Rockfall Hazard Assessment for Access Road to dam “Sveta Petka” using Rockfall Hazard Rating System (RHRS)

Large number of roads in our country are constructed in mountainous and hilly terrains. Execution of cuts in the hard rock masses is inevitable. In light of the geological nature of the rocks, processes like rockfalls and landslides in different forms and magnitude are very usual. They occur during construction activities and afterwards in exploitation of the roads. Correct protective measures must be undertaken in order to secure the safety of traffic and people using this roads. One such case is the access road to Dam “Sv.Petka”, where constant rockfalls, result of great rupture tectonics and steep cut angles built in marbly limestones, endanger the safety of traffic and construction workers using this road. In order to stress out the hazard invoked by rockfalls and the need of protective measures, we used the well established Rockfall Hazard Rating System (RHRS). Posted speed limit has great influence. Along other possibilities that this method offers is the planning of annual programs for protection measures, with separation of most dangerous zones according the classification, before any undertaking of geotechnical analyses of slope stability. Further software modeling is needed in order to get a better understanding of the nature of rockfalls