覆岩离层区积水引发的采场突水机制研究

STUDY OF MECHANISM OF STOPE WATER INRUSH CAUSED BY WATER ACCUMULATION IN OVERBURDEN SEPARATION AREAS

通过工程探测和理论分析,就海孜煤矿745工作面巨厚火成岩条件下顶板异常突水事故的机制进行深入研究。研究结果表明:距开采煤层62 m的巨厚火成岩下封闭的离层区积水是引发745工作面异常突水的水源;按传统估算方法计算导水裂隙高度为25.3～36.5 m,不会沟通巨厚火成岩下的离层区积水,但由于离层区积水的载荷传递作用,导致下部2层亚关键层发生复合破断,使得顶板导水裂隙高度异常发育,沟通了离层区积水,这是引发745工作面异常突水事故的原因。突水机制表明,可以通过向积水离层区施工放水钻孔的方法来防治此类突水事故。

Through engineering geology investigation and theoretical analysis, the mechanism of abnormal water inrush in the roof of working face 745 under the condition of giant thick igneous rock cover in Haizi mine is researched. The results show that the water accumulation in the separation area under the giant thick igneous rock cover with 62 m away from the coal seam is the water source that causes the abnormal water inrush of working face 745. According to the traditional estimation method, the height of water flowing fracture zone is 25.3 - 36.5 m, which can not connect the accumulated water in the separation area under the giant thick igneous rock. However, the loading transfer effect of separation area water induces compound breakage of two inferior key strata in lower part, so height of water flowing fracture zone develops abnormally, and it connects separation area water, which is the reason of the 745 working face abnormal water inrush. The mechanism of separation area water inrush indicates that probing and discharging borehole drilled to the separation area can prevent this kind of water inrush.