巨厚砾岩孤岛工作面微震特征研究

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

为有效防治巨厚砾岩孤岛工作面的冲击地压,运用微震监测技术,开展了针对千秋煤矿21141孤岛工作面的微震时空演化特征规律及周期来压与超前支承压力之间的相关性研究。结果表明,微震事件高发区域有3个：Ⅰ区为21141孤岛工作面前方50-300m范围内,Ⅱ区为21141孤岛工作面距采区胶带下山600-900m范围内,Ⅲ区为21采区下山煤柱区域,微震事件多发生在工作面前方的垮落带;顶板周期来压前,微震事件的频次、日累计能量有所增加,顶板来压期间,微震事件的频次、日累计能量都明显高于非来压期间的事件频次及能量;大部分冲击地压发生在超前支承压力峰值范围。

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 of50-300min the front of No.21141 island working face,Ⅱarea is within the scope of 600-900mbetween 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.