Coal Engineering ›› 2023, Vol. 55 ›› Issue (2): 12-18.doi: 10.11799/ce202302003

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Study on reasonable coal pillar width of coal-rock gob-side entry driving in inclined coal seam

  

  • Received:2022-10-13 Revised:2022-11-24 Online:2023-02-20 Published:2023-03-27

Abstract: Aiming at the problem of asymmetric large deformation of surrounding rock caused by unreasonable coal pillar width in gob-side entry driving in inclined coal seam, 1509 return airway of a mine in Guizhou was taken as an example to study the reasonable coal pillar width of this kind of roadway. Based on the limit equilibrium theory, the calculation model of reasonable coal pillar width of coal-rock gob-side entry driving in inclined coal seam is established. Combined with the actual production geological conditions of the mine, the reasonable theoretical width of coal pillar is 4.68~5.46 m. The distribution of plastic zone, stress and displacement evolution of surrounding rock of 1509 return airway under five different widths of coal pillars are analyzed through numerical simulation. It is concluded that when the width of coal pillar is 5m, the stability of roadway is better and the recovery rate of mine can be guaranteed. After comprehensive consideration, it is determined that 5m wide coal pillar should be retained for the subsequent excavation of 1509 return airway. In the industrial test, the results of mine observation and surrounding rock drilling detection in the stable section of the subsequent new excavation support of 1509 return air roadway show that after the roadway is excavated and protected by retaining 5m wide coal pillars, compared with the original design at the same time, the contour of the roadway is relatively complete, the deformation is obviously reduced, the inner wall of the roof and the two sides of the borehole is smooth and there is no collapse hole, and the integrity of the surrounding rock is good, which is conducive to improving the stability of the coal-rock gob-side entry driving in inclined coal seam, and further verifies the reliability of the research results.

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