煤峪口矿进入九十年代中前期,全部采煤工程进入11~12#408和11~12#307两个盘区,两个盘区均为厚煤层,为了提高资源回收率,均采用上下分层开采。由于地质情况和采掘接替紧张等原因,出现下分层掘巷漏顶或与上分层漏通。通常,中线点一般全部固定在顶板上,而下分层巷道没有顶板,只有 Meiyukou coal mine entered the early nineties, all coal mining projects into the 11 ~ 12 # 408 and 11 ~ 12 # 307 two panels, two panels are thick seam, in order to improve the recovery rate of resources, are used up and down Stratified mining. Due to geological conditions and mining take over the tension and other reasons, the emergence of the next stratified digging Lane Drainage or stratified through the upper strata. Normally, the midline point is generally all fixed on the roof, while the lower stratification laneway has no roof, only