Quantitative evaluation on rock stability in 5_1-7_2 seam section of Renlou Mine

According to the factors influenced to the rock mass stability and in combination with the released information of the drilling boreholes,the single factor analysis and fuzzy comprehensive evaluation method were applied to study the stability degree of the rock mass in 51-72 seam section.The study showed that the rock mass in 51-72 seam section would be mainly in fracture and loose structure,the folded development degree was mainly in medium development,the unidirectional compressive strength of the rock was 60% ranging from 30～45MPa.The rock mass were mainly in the fine sandstone-mudstone sedimentation zone.The stability of rock mass in the in 51-72 seam section was about 65% mainly ultimate instable and instable,about 25% quite stable and about 10% stable.The evaluation results were basically the same to the mine actual released conditions and could provide the basis for the mine roadway layout and support mode selection.