采空区上覆岩层裂隙发育及瓦斯流动规律分析

Analysis on Fracture Development Law in Overlying Strata of Goaf and the Gas Flowing Law in Fracture Field

针对煤矿采空区上覆岩层裂隙发育,采动裂隙瓦斯流动规律等对合理确定高位钻孔抽采区域的重要性,对采空区上覆岩层的裂隙发育规律和采动裂隙场的瓦斯流动规律进行分析,从采空区覆岩"竖三带"裂隙分布特征、采动裂隙"O"形圈以及U型通风采动裂隙瓦斯流动规律出发,找出采空区对工作面上隅角瓦斯超限影响较大的区域,得出高位钻孔的理论最佳抽采区域大致为工作面后方50 m区域,这个区域的覆岩裂隙发育情况是高位钻孔层位优化设计的关键,为高位钻孔抽采参数优化提供了理论基础。

The fracture development in overlying strata of goaf and the flowing law of gas in mining-induced fracture field is important to reasonably locating the area of gas drainage with high-level borehole.So,this paper analyzes the development law of fracture in overlying strata and the flowing law of gas in mining-induced fracture field.Basing on the fracture distribution in ＂vertical three-zone＂ and the distribution of mining-induced ＂O＂ type fracture ring in overlying strata of goaf,and the gas flowing law in mining-induced fracture under ＂U＂ type ventilation,the areas in goaf,which have great influence on gas overrun at upper corner of working face,are fount out,the optimal area of gas drainage by high-level borehole is located at about 50 m behind working face in theory,and it is considered that the developmental conditions of fracture in overlying strata in this area is a key to the optimal design of strata level arrangement of high-level borehole.The study provides a theoretical basis for the parameters optimization of gas drainage by high-leve borehole.