深埋煤层典型断层导渗性研究

Study on permeability of typical faults in deep coal seams

城郊煤矿深部二水平南翼煤层埋深大、底板含水层水压高、小断层发育,导致深部二水平煤层开采突水危险性高。针对该问题,采用断层压渗试验技术,对主要断层导渗性开展研究。通过现场压水试验结果表明,F N-6断层在起始导渗、稳态导渗和渗透系数等量化数据方面均表现出阻渗性能非常强的特点。根据F N-6断层多次正反向压渗取得的渗透系数与压注流量随时间变化情况,总体反映出两者随时间呈基本一致的变化相关性,各次压渗渗透系数最大值均相对较小,属于微透水及极微透水级别范围,反映该段断层表现出很强的阻渗能力特征。

The deep coal seam of the second-level south wing of the Chengjiao Coal Mine has a large burial depth,high water pressure in the aquifer of the floor and the development of small faults,which leads to a high risk of water inrush from the mining of the deep second-level coal seam.Aiming at this problem,the fault permeability test technology was used to study the permeability of the main faults.The results of on-site pressure water test showed that the F N-6 fault had the characteristics of very strong barrier performance in the quantitative data of initial permeability,steady-state permeability and permeability coefficient.According to the change of the permeability coefficient and the pressure injection flow rate obtained by multiple forward and reverse pressure infiltrations of the F N-6 fault with time,the overall reflection of the two was basically consistent with time.The maximum values were relatively small,which belonged to the range of micro-permeable and ultra-permeable levels,reflecting that the faults in this section exhibit strong characteristics of impermeability.