Study on mining roadway layout in lower seam of close seam group
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Abstract
The face of close seam group is easy to interact with each other, mechanical environment of the surrounding rock in the lower stope is complex, and the high roadway layout requirements, reasonable layout of roadway is the key to efficient mining of lower coal seam.In order to solve the problems of roadway layout in lower seam, field measurements, numerical calculations, theoretical analysis and other methods are adopted to study the range of roadway loose circle,the roadway layout influence factors and the roadway layout parameters, results show that the residual coal pillar bearing of upper stope, the upper goaf water and the mining action of the same coal seam are the main influence factors of roadway layout in lower seam; the bearing shape of residual coal pillar is saddle-shaped, the bearing will transfer to the floor and form the stress concentration in the floor rock near the pillar, stress intensity is negatively correlated with the distance from the residual pillar; the pressure distribution feature in the roadway surrounding is “increase-decrease-increase-decrease” under the mining action of the near stope of the same coal seam, and it is easy to superimpose the mining action of the upper and lower stope; the key to the layout of the near-lower coal seam mining roadway is to take into account the influence of upper and lower coal seam mining and reasonably design the width of the coal pillar.
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