超大采高工作面过沟回采精准防治水技术

Precise water control technology for under-gully mining in super-high mining face

超大采高工作面开采造成上覆岩层剧烈运动,导致覆岩裂隙发育,为地表及含水层水体提供流动通道,成为了矿井安全生产的隐患。以上湾煤矿12402超大采高工作面为背景工程实践,进行离散元数值模拟,揭示了工作面回采过程中上覆岩层导水裂隙带高度发育规律,结果表明导水裂隙带能够贯通地表,沿工作面倾向上覆岩层导水裂隙形态呈现“马鞍形”分布,由于采空区中部区域压实作用,工作面斜巷对应上覆区域成为防治水重点区域;同时该工作面上方为石灰沟,沟内积水量约10万m3,且地表下沉变形量达7.19m,在降雨量较大季节时易造成地面积水,对井下防治水工作提出了挑战。针对此,提出了井上下一体化精准防治水技术,包括地面采用提前疏放和塌陷坑回填措施、设置地面水文观测孔自动监测水位、井下调整工作面开采参数、精准探放水、优化设置排水设施安装地点和管路参数,制定防治水应急预案。工程实践表明,应用上述技术措施,能够有效降低大采高工作面涌水量,确保井下安全生产。

The mining of the super high working face causes the violent movement of the overlying strata, leading to the development of overburden fractures and formation of flow channels for the surface and aquifer water, which is a hidden danger against safe mining. Based on the engineering background of 12402 super-high working face in Shangwan Coal Mine, discrete element numerical simulation is carried out to reveal the height development law of the water conducting fracture zone of the overburden during the working face mining, and it is obtained that the water conducting fracture zone reaches the surface, and the fractures of the overburden along the working face dip is shaped as a saddle. As the central area of the goaf was compacted, the overlying area above the inclined roadway of the working face is the key area for water control. As there is a lime ditch above the working face, containing about 100000m~3 water, and the surface subsidence reaches 7.19m. In the rainy season, water is likely to accumulate on the surface, which is a challenge to the underground water control. In view of this, a precise ground-underground water prevention and control technology is proposed, including the advance drainage and backfilling of collapse pits on the ground, setting of surface hydrological observation holes to automatically monitor water level, adjustment of mining parameters of working face, accurate water detection and drainage, optimization of the setting of drainage facilities installation sites and pipeline parameters, and the formulation of water prevention and control emergency plans. The engineering practice shows that the application of the above technical measures can effectively reduce the water inflow of the super-high working face and ensure the safe mining.