基于微震系统孤岛工作面初次来压及周期来压步距研究

Based on the study of initial pressure and periodic pressure step of the isolated island working face of microseismic system

根据工作面回采初期固支梁结构理论,计算老顶断裂时的极限跨距,确定工作面初次来压步距,根据理论比例,计算周期来压步距范围;然后利用工作面安装的微震系统,分析工作面微震事件频次、能量的变化,反推工作面初次来压、周期来压时间,根据推进度,确定初次来压、周期来压步距;最后将通过计算及分析微震监测数据得出的初次来压、周期来压步距进行对比,二者基本吻合,得出可以利用微震监测系统确定工作面初次来压、周期来压步距的结论。

According to the structural theory of fixed support beam in the early stage of stoping,the limit span of fracture of the old roof is calculated,and the initial pressure step distance of working face is determined.According to the theoretical proportion,the interval of pressure step distance is calculated.Then,the microseismic system installed on the working face is used to analyze the change of frequency and energy of microseismic events on the working face,and to push back the initial pressure and cycle pressure time of the working face.According to the degree of advance,the initial pressure and cycle pressure step distance are determined.In the end,the initial pressure and the period of pressure step obtained from the calculation and analysis of microseismic monitoring data are compared.The two are basically consistent,and a conclusion is drawn that the microseismic monitoring system can be used to determine the initial pressure and the period of pressure step.