Prediction of CMRS rock mass rating using fuzzy logic

CMRS (Central Mining Research Station) Geomechanical rating of rock mass is a classification system based on the various parameters which was defined by CMRS. The rating system may possess some fuzziness in its practical applications. For example, groundwater seepage and weatherability (measured by I Cycle slake durability) are related by experts in linguistic terms with approximation. Descriptive terms vary from one expert to another, while in the RMR system values which are related to these terms are probably the same. On the other hand, sharp transitions between two classes create uncertainties. So it is proposed to determine new weight interval for these parameters. Fuzzy model based on the Mamdani algorithm was introduced to evaluate proposed weights, so that the linguistic approximation based problem could be solved. Further, experiments are done with some of coal mines areas where this fuzzy based rock mass rating gives more satisfactory result than the existing CMRS rating techniques.