为避免深部矿井高应力煤柱对巷道产生的不利影响,基于塑性滑移场理论、极限平衡理论,结合数值模拟方法,以葫芦素矿井2-1煤首采区为背景,研究区段煤柱集中载荷作用下底板承压破坏范围及其对巷道围岩稳定性的影响程度。结果表明:目前葫芦素2-1煤留设的30 m区段煤柱在侧向支承压力作用下对底板岩层的影响较大,其承压破坏带覆盖整个巷道底板范围,造成巷道底臌严重。为此,提出了“一高一低”的高应力区段煤柱综合卸荷技术,即高位“钻、切、压”一体化技术切断覆岩应力传递,低位煤层小孔径爆破技术释放煤柱内的集聚载荷。现场实验结果表明:卸荷后煤柱内部应力峰值由22. 5 MPa降至15. 7 MPa,压降明显,巷道变形得到有效控制。

Deep mines are generally faced with the problem of high stress in the coal pillars,which causes the serious deformation of the roadway. The main reasons for this are the unreasonableness of the coal pillars. In order to avoid the adverse effect of high-stress coal pillars on the roadway,taking the 2 -1 coal seam first mining area of the Hulusu mine,China,as a background,the deformation and failure range of the bottom slab under the concentrated load of the coal pillar and its influence on the roadway surrounding rock were studied based on the theory of plastic slip field and limit equilibrium theory. The results show that the 30 m section pillar reserved for Hulusu 2-1 coal seam currently has a greater influence on the floor rock under the effect of lateral support pressure,and its pressure failure zone covers the entire roadway floor area,which cause the roadway floor heave seriously. In order to effectively solve this problem,the “high and low” high-strength coal pillar comprehensive unloading technology was proposed. That is,the high-level “drilling,cutting,pressing” integrated technology cuts the stress transfer of the overlying rock,and the low coal seam small-bore blasting technology releases the accumulated load within the coal pillar. The results of field experiments show that the peak value of internal stress of coal pillars after unloading is from 22. 5 MPa to 15. 7 MPa,the pressure drops significantly,and the roadway deformation is effectively controlled.