近距离煤层蹬空开采底板应力分布规律

Floor Stress Distribution Laws of Mining Above Gob in Close Distance Coal Seams

近距离煤层刀柱式采空区上方进行综采回采工艺时,由于其残留煤柱上覆岩层垮落不充分,在采动压力作用下,造成下煤层老采空区残留煤柱失稳,形成应力集中区,进而引起残留煤柱上覆岩层不规则垮落破坏,造成综采工作面底板岩层失稳,威胁综采工作面安全生产。针对唐山沟煤矿刀柱式采空区上方8#煤层回采实际,对其工作面底板进行受力分析,确定出工作面安全长度,并运用UDEC数值模拟对刀柱式采空区上方工作面应力及底板塑性区进行了分析。

When fully mechanized coal mining technology was conducted above the knife gobs in close distance mine seams, due to the inadequate collapse of overlying strata of residual coal pillars, in the action with mining, it could cause the instability of residual pillar in the old goaf of the lower coal and form stress concentration area, and then cause the overlying strata of residual coal pillars irregular collapse damage and the instability of floor strata in mining working face, which threatens the safety in production of mining face. According to the 8# coal seam above knife gobs of Tangshangou Coal Mine, this article researched the working face floor with the force analysis, determined the safety length of working face, and then analyzed the stress of face above the knife gob and the plastic zone of its floor by using UDEC numerical simulation.