特厚煤层综放开采底板破坏及阻隔水性能分析

Bottom Destruction and Barrier Performance Analysis of Fully Mechanized Caving Mining in Extra-thick Coal Seam

唐家会煤矿主采煤层为6煤煤层,均厚17.2m,距奥灰含水层33.5~69.60m,采用综合机械化放顶煤开采煤。由于特厚煤层采动底板破坏深度大,为确保开采安全,进行了采前水文地质补勘和底板岩层阻隔水性能、水理性质以及采动破坏深度探测试验研究。结果表明:饱和抗压强度偏低,岩石干抗压强度较高;底板30m范围内,岩石石英含量较高,呈脆性破坏特征,渗透性能强,自身隔水性能差;与奥灰含水层接触铝土泥岩,厚度均大于5m,分布稳定,含粘量较高,垂向渗透能力弱,原始导升低;特厚煤层综放采动底板破坏深度26.30~26.80m;破坏深度以下距奥灰顶部岩层粘土矿物含量高;隔水性能与再生隔水能力强,渗透性能弱,吸水后体积膨胀;受采动影响后,具有阻隔奥灰水突涌和抑制底板破坏深度向下延展的双重作用,突水系数0.025~0.044MPa/m;根据以上研究结果,成功进行了61101、61103等综放面带压高效试采,经济效益非常显著。

The main coal seam of Tangjiahui Coal Mine consists of 6 coal seams with a thickness of 17.2 m and a distance of 33.5~69.60 m from the strong aquifer of the Austrian ash. The coal is mined by comprehensive mechanized top coal caving. Due to the large depth of damage of the mining floor of the extra-thick coal seam,in order to ensure the safety of mining,the pre-harvest hydrogeological reconnaissance and the barrier water performance,water-physical properties and mining failure depth detection test of the floor rock layer were carried out. The results show that the saturated compressive strength is low and the rock dry compressive strength is high. Within 30 m of the bottom plate,the rock quartz content is high,showing brittle failure characteristics,strong permeability and poor water barrier performance;contact with the aeronautical aquifer. The thickness of the bauxite is more than 5 m,the distribution is stable,the viscosity is high,the vertical permeability is weak,and the original lead is low;the depth of the fully mechanized caving miningfloor in the extra-thick coal seam is 26.30~26.80 m. The top rock layer has a large clay mineral content;the water-blocking property and the regenerative water-blocking ability are strong,the permeability is weak,and the volume is expanded after water absorption;after being affected by the mining,it has the dual function of blocking the sudden overflow of the Austrian grey water and suppressing the downward extension of the floor damage depth. The water inrush coefficient is0.025~0.044 MPa/m. According to the above results,the high-efficiency test mining of 61101,61103 and other fully mechanized caving faces has been successfully carried out,and the economic benefits are very significant.