Rockfall Hazard and Its Mitigation with Focus on Rock-Sheds: A Review

Rockfall is a major problem in hilly areas. Falling rocks pose a great threat to human life and engineering structures lying in these areas. To mitigate the hazard of rockfall, broadly two types of techniques are used, namely active protection and passive protection techniques. Active protection measures are those which prevent the rockfall from occurring, whereas the passive protection measures reduce the damage caused by the falling rocks. Rock-sheds have been considered as important passive protection structures for protection of roads or railway lines in the areas which are prone to rockfall. Rock-sheds are made up of reinforced concrete with a cushion layer on the top. The cushion layer can be of soil or a composite layer having soil and some other energy absorbing material which can dissipate the impact energy of rockfall and protect the rock-shed. In this paper, the work done by various researchers in the field of rockfall hazard has been discussed. Various active and passive protection measures to mitigate the rockfall hazard along with the benefits and limitations of each measure have been highlighted. The paper focuses on the importance and design of rock-sheds. Therefore, this paper discusses the design of rock-shed, the thickness of cushion layer, the various energy absorbing materials which can be used as cushion layer, and the research carried out in this area so far, and exhaustive conclusion has been made in this regard.