The support effectiveness of mining gateway at closed-distance seam is determined by the layout of mining gateway and the stress effect of the upper coal pillar load on the bottom seam. The stress effect is affected by the coal pillar size and the properties of the coal pillar and surrounding rocks. These factors may cause the variation of the stress concentration, which could cause the difference in the stress distribution on the bottom seam. This paper studies on the proper coal pillar size of ultra closed-distance upper and bottom coal seam in Fu Cheng coal pit and the layout of the mining gateway.
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