Coal Engineering ›› 2025, Vol. 57 ›› Issue (3): 35-43.doi: 10. 11799/ ce202503006

Previous Articles     Next Articles

Roof cutting and pressure relief technology fr gob-side entry in medium-thick coal seam of kilometer-deep mine

  

  • Received:2024-05-21 Revised:2024-08-04 Online:2025-03-10 Published:2025-05-15
  • Contact: ding kunpeng ding kunpengding kunpeng E-mail:514270212@qq.com

Abstract:

Aiming at the problem of severe mine pressure in the gob-side entry of small coal pillar of Pingdingshan No.12 coal mine, the overburden structure and its mechanical influence at the end of the working face, the principle of roof cutting and pressure relief technology and the combined blasting method of deep and shallow holes are studied. The research shows that the fracture form of the basic roof has a significant effect on the stability of the surrounding rock of the gob-side entry, and the load of the coal pillar and the gob-side entry is the smallest when the cantilever length is small and the fracture position of the basic roof need to located outside the coal pillar. In order to solve the technical problem of hard roof blasting in 1 000 m deep mine, a deep-shallow hole combined directional control blasting method with “deep hole (explosives)-shallow hole (explosives)-deep hole (no explosives)” cyclic arrangement is proposed, and the directional fracture of hard roof is realized under the action of deep-shallow holes shaped blasting energy and control holes guidance. Combined with the geological characteristics of the working face, it is determined that the target height of roof cutting is 30.7m, the angle of roof cutting is 15° to the side of goaf, the diameter of deep hole is 94mm, the diameter of shallow hole is 55mm, the spacing of borehole is 0.8m, the position of borehole opening is 0.6m from the side of roadway, the depth of deep hole is 32.5m, and the depth of shallow hole is 15m. The practice shows that the combination of deep and shallow hole directional control blasting method has good seaming effect, and can effectively control the stress of gob-side roadway, which provides reference for safe and efficient mining in mines with similar conditions.

CLC Number: