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Coal Engineering ›› 2023, Vol. 55 ›› Issue (7): 45-50.doi: 10.11799/ce202307008

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Roadway surrounding rock control technology for stress-concentration area of boundary pillar in coal seams group staggered working face#br#

  

  • Received:2021-11-25 Revised:2022-06-26 Online:2023-07-20 Published:2025-04-07

Abstract:

The 31113 return airway of Lijiahao Coal Mine was located in the coal pillars at the boundary of the dislocation working face, and the roadway deformed greatly at the 31113 working face before the stoping. In order to obtain the mechanism of large deformation of the roadway and propose the control technology, the method of numerical calculation and field measurement was used to study the force characteristics and failure laws of the surrounding rock of the roadway. The research results showed that the superposition of the concentrated stress of the coal pillars in the upper group of coal seams and the lateral support pressure of the 31112 face in the lower group of coal seams resulted in a substantial increase in the roadway force, and the lack of original support strength resulted in a large deformation of the roadway. The main reason for the substantial increase in superimposed stress was that the concentrated stress transmitted by the coal seams on the dislocation working face comes from the boundary coal pillars, and the downward conduction stress of the boundary coal pillars had a larger influence than the inter-section coal pillars, and the attenuation was slower. At the same time, the superposition of lateral support pressure intensified the imbalance of the surrounding rock force of the roadway. The damage range of the roadway surrounding rock on the side of the auxiliary side and the roof of the auxiliary side near the adjacent mined-out area was relatively large, causing local instability of the roadway and forming Large deformation. The original support plan was revised based on the actual damage range, and the reinforcement support plan was designed. The field measurement showed that the roadway deformation was significantly reduced after the reinforcement support.

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