采动破坏新近系地层隔水性能恢复可行性试验研究

Experimental Study on Water-proof Restoring Feasibility of Neogene Strata Destroyed by Coal Mining

由于伊犁一矿煤层与松散层含水层距离小,基岩薄且极软弱破碎,开采易产生突水、突泥、溃砂现象,新近系上部隔水层是煤层开采的关键隔水层,其受采动破坏的隔水性能恢复可行性成为影响工作面开采突水突泥溃砂的关键因素。为探讨分析伊犁一矿新近系地层受采动破坏后隔水性能恢复可行性,以伊犁一矿SW-3孔采取的新近系地层为研究对象,通过进行X射线衍射分析获得岩石的矿物成分及其含量,扫描电镜获得岩石内部结构形态,并利用RT多场耦合试验仪,分析新近系地层试样不同裂隙宽度在相同的试验条件下对应的渗透率变化情况,判断隔水层恢复的可行性。试验结果表明采动破坏新近系地层表现出隔水性恢复性能,采动裂缝宽度越小,裂隙愈合能力越强,裂隙愈合时间越短。

Because the distance between the coal seam and the loose aquifer in Yili No.1 Coal Mine is small,and the bedrock is thin and extremely weak and broken,the phenomena of water inrush,mud inrush and sand burst are easy to occur in mining,the upper aquifuge of Neogene is the key waterproof layer in coal seam mining.The feasibility of restoration of water insulation performance destroyed by mining has become the key factor affecting water inrush,mud and sand burst in working face mining.In order to explore and analyze the feasibility of the water-proof restoration of Neogene strata in Yili No.1 Mine after mining damage,the Neogene strata in SW-3 hole of Yili No.1 Mine was taken as the research object.The mineral composition and content of the rock were obtained by X-ray diffraction analysis,and the internal structure of the rock was obtained by scanning electron microscopy.The permeability variation of Neogene formation samples with different crack widths under the same test conditions is analyzed to judge the feasibility of the recovery of water barrier.It is found that the smaller the crack width is,the stronger the crack healing ability is and the shorter the crack healing time is.