ABSTRACT: A number of civil engineering projects which include river valley projects, transportation projects and metro rail projects are under construction in India. Various structures, such as underground openings, powerhouse caverns, metro tunnels, dam foundations and slopes are increasingly located in/on rock formations. The rock in its natural state is a very complex material especially wh...

The presence of complex discontinuity patterns, the inherent statistical nature their geometrical parameters, uncertainties involved in estimation and geo-mechanical properties three dimensional (3-D) in-situ stress make accurate prediction rock mass strength a difficult task. It has been great challenge for mechanics engineering professions to develop criterion dimensions that incorporates eff...