Research of microseismic characteristics of island working face with huge thick conglomerate

For preventing and controlling of rock burst in island working face with huge thick conglomerate effectively, relevance research is carried out for No.21141 island working face in Qianqiu Coal Mine about space-time evolution characteristic law of microseismic and correlation between periodic roof pressure and advanced abutment pressure using microseismic monitoring technology. The results show that there are three high incidence districts about microseismic events:Ⅰ area is within the scope of 50~300 m in the front of No.21141 island working face,Ⅱ area is within the scope of 600~900 m between No.21141 island mining face away from belt downhill, and Ⅲ area is downhill coal pillar in the No.21 mining area. Microseismic events mostly occur in caving zone in front of working face. Before periodic roof pressure, frequency and daily cumulative energy of microseismic events increase. While during the period of periodic roof pressure, frequency and daily accumulated energy of microseismic events are obviously higher than those outside of the periodic roof pressure. Most rock bursts occur in peak range of advanced abutment pressure.