近距煤层群底板大巷掘前卸压开采技术研究

Research on depressurized mining technology before developing floor strata tunnel in close coal-seam group

为合理设计钱家营矿近距煤层群底板岩石大巷层位和施工顺序,减缓动压影响,采用理论分析、数值模拟等手段对大巷合理布置位置、减压开采工作面尺寸及减压开采效果技术论证与对比研究。结果表明:底板大巷应在上方采面回采结束底板稳定后掘进,采面斜长至少为两倍的支承压力影响范围,巷道应布置在采面底板破裂影响范围外;钱家营矿采用180 m的9煤层卸压工作面开采,回风巷布置在12-1煤层底板岩层中,巷道两帮围岩应力降低明显,顶底板移近量为389 mm,两帮移近量为324 mm,减压开采效果良好,有利于巷道的长期维护和运营使用。

In order to reduce the mining dynamic pressure adverse effect on floor strata ventilation roadway in close coal-seam group of Qianjiaying mine,main roadway's reasonable layout,length and effectiveness of pressure relief mining are researched by theoretical analysis,numerical simulation,etc.The results indicate:the bottom roadway should be exploited after the depressurized face recovery and its floor strata stability;length of upward mining plane is twice of support pressure range at least,and roadway should be arranged out of the fracture's distribution of mining face's floor strata;applying depressurized mining technology with180 m depressurized face in coal 9 and return-air roadway layout in coal 12-1 floor rock layer,the maintenance conditions of roadway are very effective,which could be explained by obviously reduced stress,roof-floor displacement reducing to 389 mm,side coal-walls displacement reducing to 324 mm.This kind of scheme is advantageous to maintain and use roadways safely.