高强度回采的首采面一次见方期矿压规律研究

Study on law of mine pressure in the first mining face of high-intensity mining in the first square period

神东煤炭集团布尔台煤矿301综放工作面作为12上煤层的首采面,在一次见方期的日进尺平均达到8.35 m的高强度级别。为研究高强度回采的首采面在一次见方期的矿压规律,通过钻孔应力计、微震系统和支架压力系统进行联合监测分析。应力计监测表明,301强采动首采面在一次见方期间超前支承压力影响范围分为缓慢影响范围和剧烈影响范围;主要运输巷正帮侧9 m和副帮侧7 m范围内、辅助运输巷正帮侧15 m和副帮侧5 m范围内,受采动影响较大而易导致煤体塑性破坏,呈现帮鼓及锚杆失效等问题。由微震监测和支架压力可知,工作面在见方前后40 m时,上覆岩层运移较强烈;工作面距离见方位置越近,上覆岩层运移越强烈;在见方后30 m左右,顶板活动最剧烈,支架压力较大。

As the first mining face of 12-upper coal seam,the No.301 fully-mechanized caving face of Buertai Coal Mine of Shendong Coal Group,the average daily footage in a square period reaches a high strength level of 8.35 m.To study the law of mine pressure in the first mining face of high strength mining,the joint monitoring and analysis were carried out by drilling stress meter,microseismic system,and support pressure system.Stress meter monitoring shows that the influence range of advance supporting pressure in the first mining face of No.301 strong mining is divided into slow influence range and severe influence range.In the range of 9 m on the main side and 7 m on the auxiliary side of the main transportation roadway,and in the range of 15 m on the main side and 5 m on the auxiliary side of the auxiliary transportation roadway and 5 m on the side of the auxiliary side,the plastic failure of the coal body is easily caused by the mining influence,and the problems of side drum and bolt failure are presented.From the microseismic monitoring and support pressure,when the working face is 40 m before and after the square,the overlying rock migrate more strongly.The closer the working face is to the square position,the stronger the overlying rock migration is.At about 30 m after the square,the roof activity is the most intense,and the support pressure is large.