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In order to reveal the failure morphology and mine pressure behavior of overlying strata during shallow buried close multi-coal seam mining, this research takes the Shenmu Zhangjiamao mining area as the engineering background, the study of overlying rock movement and mine pressure distribution law in shallow and close coal seams was carried out. The results show that: with the gradual mining of 2−2 coal seam, the support stress in front and back of the working face increases first and then decreases, and the compaction strength of the collapsed overburden in the middle of the mined-out area increases gradually. With the mining of 2−3 coal seams, the displacement of the direct roof of the lower mined-out area and the rock layer of the upper compaction area increases gradually. With the increase of interlayer spacing, the peak stress in the concentrated stress area on both sides of the 2−3 coal seam decreases gradually. The compaction stress of overlying strata in the upper mined-out area decreases gradually, and the peak value of compaction stress in the middle of the lower goaf increases gradually. Through the measured results of the borehole stress sensor and separation instrument, the obvious influence range of the advance support pressure of the working face is about 40 m. The research results can provide practical experience for similar coal seam group mining in other mines, and can also be used to study the mining pressure behavior of inclined close distance multiple coal seams.
Hu et al. (Sat,) studied this question.