Rock mass rating
![Input Chart for determining RMR parameter intact rock strength](/Images/godic/202502/07/RMR_chart,_strength_ratings0947.jpg")
![Input Chart for determining RMR combined parameters RQD and discontinuity spacing](/Images/godic/202502/07/RMR_chart,_joint_density_ratings0947.jpg")
![Output Chart for determining Stand Up Time for Tunnels as a function of RMR](/Images/godic/202502/07/Stand_Up_Time_for_tunnels_in_civil_and_mining_engineering_as_a_function_of_RMR0947.jpg")
![Output Chart for determining rock mass deformability modulus Em as a function of RMR](/Images/godic/202502/07/Rock_mass_modulus_of_deformation_Em_as_a_function_of_RMR0947.jpg")
The Rock Mass Rating (RMR) System is a geomechanical classification system for rocks, developed by Z. T. Bieniawski between 1972 and 1973. It combines the most significant geologic parameters of influence and represents them with one overall comprehensive index of rock mass quality, which is used for the design and construction of excavations in rock, such as tunnels, mines, slopes and foundations.