College of Energy Engineering,Xi’an University of Science and Technology;Key Laboratory of Western Mine Mining and Disaster Prevention,Ministry of Education,Xi’an University of Science and Technology;Key Laboratory of Coal Resources Exploration and Com- prehensive Utilization,Ministry of Natural Resources;Zhundong No.2 Mine, National Energy Group

An extremely high mining intensity of working face can easily lead to some dynamic disasters such as rock burst,so it urgently needs to discuss the reasonable mining intensity of working face for the safe and efficient mining operation of rock burst mines. Based on No. 1101 fully mechanized top-coal caving face in the first layer of extremely thick coal seam with strong impact tendency in the Zhundong No. 2 Mine, the comprehensive analysis method,combining theoretical analysis with physical similarity simulation experiment,was adopted to analyze the mining stress and energy evolution law of overlying strata under different mining intensities. Also the impact risk of coal and rock mass under different mining intensities was evaluated. The reasonable mining intensity of the working face was determined, and the characteristics of high-intensity mining in rockburst mines were obtained and defined. Meanwhile,the regulation mode of high-intensity mining in rockburst mines was put forward. The results show that:1 With the increase of mining intensity,the mining stress,stress concentration coefficient and periodic weighting step are steadily increased. The microseismic energy increases gradually,and the accumulation range of large energy also increases gradually. The impact risk of working face also increases gradually with the advancing speed,and its impact risk index Im and microseismic energy Er are positively correlated with mining intensity,while the microseis- mic value b shows a negative correlation. Comprehensive analysis shows that the advancing speed of No. 1101 working face should not be greater than 8 m / d. 2 High-intensity mining in rockburst mines is not an external mining intensi- ty,but a mechanical state of comprehensive reaction stress,energy and impact risk,which is determined by its charac- teristic parameters. The characteristics of high-intensity mining in the Zhundong thick coal seam are defined as advan- cing speed greater than 8 m / d,the ratio of weighting step to advancing speed less than 1,impact risk index Im > 3,micro- seismic single energy greater than 214.38 J,and microseismic value b is less than 0.7.3 It is pointed out that the key to pre- vent and control the high-intensity mining of rockburst mines lies in regulating the mining intensity of the working face. For mines that have not reached high-intensity mining,on the premise of ensuring safe and efficient mining,the production and efficiency should be increased by adjusting the advancing speed and releasing high-quality production capacity. For mines that have reached high-intensity mining,by changing the advancing speed of working face,the stress and ener- gy distribution characteristics of surrounding rock in working face can be changed,the impact risk of coal and rock in working face can be improved,and the safe and efficient mining of rockburst mines can be ensured.

崔峰,冯港归,来兴平,等.巨厚强冲击倾向性煤层高强度开采特征与高强度开采定义[J].煤炭学报,2023,48(2):649-665.
CUI Feng, FENG Ganggui, LAI Xingping, et al. Characteristics and definition of high-intensity mining in extremely thick coal seam with strong impact tendency [ J ] . Journal of China Coal Society, 2023, 48 ( 2 ) : 649-665.