关键词: 覆岩裂隙, 高位钻孔, 采空区, 裂隙扩张区, 相似模拟

Abstract: Abstract: In order to ensure the safe and efficient mining and solve the gas problem in the upper corner of the working face, based on the research of the development law of the overlying rock fracture, this paper studies the reasonable layout of the high-level borehole in the goaf roof. Taking the 20102 comprehensive mining face of shennanao coal mine as the research background, it uses the similar simulation, theoretical analysis and field test methods to study comprehensively, and uses the similar model Based on the research of fracture evolution field and so on, the distribution and change law of overburden with the compaction area and fracture area in the mining process of the working face are determined. The research results show that in the time sequence, the overburden fracture undergoes transverse fracture development, longitudinal fracture development, fracture field expansion with the mining of the working face In the process of fracture recompaction, the fracture expansion area is the reasonable location of high-level borehole, which can effectively improve the efficiency of borehole extraction. Therefore, this paper aims to find the dynamic fracture expansion area in the process of mining. Based on the dynamic expansion area obtained from this study, the author, based on the actual situation in the field, arranges multiple high-level borehole for gas extraction, and then studies the borehole Through the analysis of the extraction parameters, it is shown that the reasonable arrangement of the high-level boreholes is within the range of 30-50m from the roof of the fracture zone, which can reasonably ensure the hole forming rate and the high-efficiency extraction efficiency. Through the analysis of the extraction data, it can be seen that the arrangement of the extraction boreholes in this layer can effectively reduce the gas concentration in the upper corner (up to about 0.4%), and can be maintained stably.