软弱岩层中近距离采空区煤柱下开采的实践

近距离采空区煤柱下长壁回采将受到上煤层采空区遗留煤柱和本煤层工作面动压的共同影响。针对乌鲁木齐某矿9#煤层顶底板为软岩的特点,在分析围岩破坏机理后,提出了梁、索协同支护+顶底角注浆锚杆加固+帮部锚杆组合支护+底板锚梁支护及全断面铺网的联合支护方案,即实施巷道"顶底帮整体化"治理,通过在巷道中布置卸压孔,有利于高应力向巷道深部转移,改善围岩与支护结构的应力作用环境。实践证明,采取上述措施有效解决了回采巷道的顶板破坏、煤壁片帮、底板鼓起等问题。在开采过程中采取的降低采高、调斜工作面、工作面加速通过煤柱的方法也使得工作面的生产条件得到了极大的改善,保证了工作面安全开采。

Practice of Mining Under Pillars in Close-distance Mined-out Area in Soft Rock Layer

Longwall mining under coal pillars in close-distance goaf will be influenced by the remained coal pillars at upper coal seam and the dynamic pressure of the coal face.In view of the characteristics that the roof and floor of No.9 coal seam of some coal mine in Urumqi are soft，the jointed support scheme of collaborative support of beam and cable + grouting reinforcement of top and bottom corners，side-wall bolting + bottom anchor and beam support+ full-section net is proposed after analyzing the failure mechanism of surrounding rocks，namely the integrated treatment of roof，floor and side-wall.Arranging the pressure-relief hole in the roadway is conducive to transfer high stress into the deep tunnel and improve the stress condition of surrounding rocks and support structures.The practice has proved that these measures effectively solved the issues such as roof damage in mining roadway，coal wall spalling and floor heaving etc..Approaches adopted in mining process，including reducing mining height，inclining working face，accelerating working face through coal pillars greatly improved the production conditions in working face，and ensured the mining safety.