Multi-index monitoring of rock burst and risk zone division of island mining coal face

Under superposition influence of stress concentration of coal pillar and dynamic pressure of working face in mining process of island mining coal face, rock burst disaster is easy to occur.At present, the single index is used to give early warning to the impact risk, which has large error in early warning and cannot fully reflect impact risk in the mining process. For the above problems, in order to study hazard degree of rock burst in the mining process of island mining coal face, taking 93down 05 island mining coal face of Jining No.2 Coal Mine as engineering background, a multi-index monitoring method of rock burst of island mining coal face was put forward. The impact risk of the working face was analyzed by means of cuttings，microseismic and borehole stress, and risk zones were divided according to the impact risk of different areas of the working face. The analysis results show that the maximum and total vibration energy of microseismic day, cuttings and borehole stress value are significantly increased in the vicinity of connection roadway and unprotected area, and it is concluded that the vicinity of connection roadway and unprotected area are the dangerous areas of rock burst during the mining process of the island mining coal face. According to the result of the classification of dangerous regions and considering the difference of stress concentration degree in different regions, a large-diameter pressure relief and anti-impact measure with parameter differences was proposed and implemented, which reduces the stress concentration degree, avoids the energy accumulation and prevents occurrence of rock burst disater.