Use of the mining rock mass rating (MRMR) classification: industry experience.
Proceedings of the International Workshop on Rock Mass Classification in Underground Mining. Mark C; Pakalnis R; Tuchman RJ, eds., Pittsburgh, PA: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, 2007 May; :73-78
In 2000, Laubscher's Mining Rock Mass Rating (MRMR) classification system was updated and published. The new system brought a few fundamental changes that were in direct response to the challenges and problems encountered when applying the classification system in the mining environment, specifically caving operations. The fundamental changes introduced into the MRMR system in 2000 were the abandonment of the Rock Quality Designation (RQD) as an input parameter, accounting for healed and cemented joints, and the concept of rock block strength. The objective of this paper is not to discuss the role and usefulness of classification systems; the fact that classification systems are widely used in every stage of mining projects speaks for itself. This paper discusses some of the experiences gained with the MRMR 2000 system in various mining projects and shows how the changes to the system have resulted in improved assessment of rock mass conditions. Issues related to core logging for rock mass assessment are also presented.
Mining-industry; Underground-mining; Coal-mining; Hard-rock-mines; Geology; Geophysics; Rock-mechanics; Analytical-models; Computer-models
National Institute for Occupational Safety and Health, Pittsburgh Research Laboratory, 626 Cochrans Mill Road, Pittsburgh, PA 15236
Marc-C; Pakalnis-R; Tuchman-RJ
Proceedings of the International Workshop on Rock Mass Classification in Underground Mining