| According to the severe situations of roadway deformation in the course of mining 72 coal seam of Renlou coal mine,Based on theories and methods of sedimentary petrology,rock mechanics,structural geology,geological engineering and fuzzy mathematics,this paper systematically rock composition, lithology zone, structure characteristics, rock mechanics characteristics, rock quality, petrofabric types were systematically analyzed.The influence of rockmass engineering geological mechnical characteristics of 51-72 coal seam section of Renlou coal mine to the rockmass stability were discussed. Combined with actual situation of the research area, evaluation indexes of coal seam section rockmass was determined,namely fault fractal dimension,compressive strength, planar deformation coefficients of folds,lithology combination value.Based on the methods of double weight, weights of all influencing factors were determined.On the basis of fuzzy comprehensive evaluation, the rockmass stability of 51-72 coal seam section was evaluated.The evaluation results supplied scientific basis of roadway layout,selection of support form,roof management to Renlou coal mine. Main conclusions are as follows: Region of siltstone– mudstone and mudstone dominated most of the 51-72 coal seam section , and they accounted for30%; Most structures of 51-72 coal seam section were block fracture and fragmention.Medium development and comparative development of folding deformation degree was major ;The weighted RQD of 51-72 coal seam section was all below 75% and"the common rock"accounted for most of the rock. Most of the petrofabric of 51-72 coal seam section was mudstone-shale petrofabri,and its stability was worse; Fault fractal dimension, planar deformation coefficients was treated as evaluation factors,which supplied a new way to the evaluation of rockmass stability.In the research area, extremely unstable area and unstable area accounted for 65%,relative stable area accounted for 25%, stable area. accounted for10%.
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