彬长矿区高位坚硬巨厚砂岩层(洛河组)破断规律分析

Analysis of breaking laws of high-level hard and thick sandstone(Luohe formation)in Bingchang mining area

4号煤为彬长矿区的主采煤层,其上覆180 m处存在着300 m巨厚砂岩层(洛河组),在工作面重复采动影响下的破断及下沉对安全回采造成极大影响,易导致冲击地压、突水等灾害的发生。针对矿井典型条件,采用力学分析及数值模拟分析的研究方法,对该高位坚硬巨厚砂岩层破断规律进行了探讨。结果表明,此岩层极限跨距为457.126 m,工作面极限宽度为568.498 m;且204、205、206及207工作面回采结束后,裂隙带仅发育至此岩层下方,裂隙带发育高度为178 m左右,该岩层尚未破断,只是呈现弯曲下沉现象。

Coal seam 4 is the main coal seam in Binchang mining area,and there is a 300 m thick sandstone(Luohe formation)at 180 m above it.Under the influence of repeated mining of the working face,the breaking and sinking of sandstone has a great impact on the safety of mining,which is easy to lead to rock burst,water inrush and other disasters.According to the geological conditions of the mine,using the research methods of mechanical analysis and numerical simulation analysis,the breaking law of the high-level hard and thick sandstone layer is discussed.The results show that the limit span of the sandstone layer is 457.126 m,and the limit width of the working face is 568.498 m.After the mining of working faces 204,205,206 and 207,the development height of the fracture zone is about 178 m,and the rock layer has not been broken,but presents the phenomenon of bending and sinking.