含气岩层对首采工作面回采的影响

Impact of Rock Containing Gas on First Mining Face

任家庄煤矿在建井及首采煤层巷道掘进过程中,遇到含有大量游离瓦斯气体的砂岩层,针对该含气岩层的分布情况,对回采工作面开采后形成的冒落带、裂隙带的高度进行经验计算和数值研究,研究结果表明该含气岩层处于开采引起的裂隙带内,在首采工作面推进400 m后,含气岩层内的游离瓦斯将直接涌入采空区,威胁回采工作面的安全生产。

A rock strata which contains abundant methane is found when return air shaft is building and tunnel is digging in Renjiazhuang mine and the phenomenon of abnormal gas emission appeared.Basing on the distribution of the siltstone strata containing gas,the height of fractured zone is computed with experience formula and numerical simulation method when first working face is advanced.The result indicates that the zone of siltstone strata which contains abundant methane locates in fracture area.when the length of the first working face exceed 400 m,the gas will flow into the working face from the siltstone strata,then it will bring great potential threat for mining.