SHANG S, YU Z L, SUN J，et al. Width optimization and deformation failure characteristics of narrow coal pillar in gob-side entry d riving in thick coal seam［J］.Journal of Henan Polytechnic University（Natural Science），doi:10.16186/j.cnki.1673-9787.2024040051

doi: doi: 10.16186/j.cnki.1673-9787.2024040051

Received：2024-04-25

Revised：2025-03-03

Online：2025-03-26

Width optimization and deformation failure characteristics of narrow coal
 pillar in gob-side entry d riving in thick coal seam

SHANG Shuai, YU Zhonglin, SUN Jian,JIA Hao

(School of Mining Engineering, Anhui University of Science and Technology, Huainan 232001, Anhui, China)

Abstract: [Objective] To study the reasonable coal pillar width of gob-side entry driving in thick coal seam and the deformation and failure characteristics of surrounding rock of gob-side entry driving after optimization, [Methods] the 9106 working face of Linfen Tianyu Hengsheng Coal Industry of Wanbei Coal and Electricity Group was taken as the engineering background. Based on the theoretical analysis of the reasonable width of coal pillar in gob-side entry driving ranging from 7.03 m to 12.44 m, FLAC3D was used to simulate and analyze the distribution characteristics of stress displacement and plastic zone of surrounding rock of gob-side entry driving when the width of coal pillar was 8 m, 9 m, and 10 m respectively. The reasonable coal pillar width of gob-side entry driving in the 9106 working face was determined to be 8 m. At the same time, the distribution characteristics of stress displacement and plastic zone of surrounding rock of 8 m coal pillar under supporting conditions were simulated and analyzed, and the feasibility of 8 m coal pillar under a supporting scheme was verified. Three schemes of roadway surrounding rock displacement monitoring, roof fracture distribution detection and coal pillar stress distribution monitoring were designed. HCZ-2 borehole stress meter, borehole peeping and DDWJ-2 multi-point displacement meter were used to monitor the distribution law of lateral abutment pressure and the failure characteristics of different positions of coal pillar in the mining process of working face when the width of the coal pillar was 8 m. The displacement variation law of surrounding rock in gob-side entry driving was analyzed. [Results] The results showed that the lateral abutment pressure exhibited a distribution pattern that increased from the working face side to the goaf side and then decreased. In the range of 0 ~ 2.5 m and 4.6 ~ 8 m, there were obvious broken fissures and broken zones in the coal pillar, which was the plastic failure zone of the coal pillar. The coal pillar was in the range of 2.5 ~ 4.6 m, and the integrity was good. This range was the elastic zone of the coal pillar. The maximum deformation rate of the two sides of the roadway at the two monitoring points of AA ' and BB ' was greater than the deformation rate of the roof and floor, and the displacement of the shallow part of the gob-side entry was significantly greater than the deep displacement. [Conclusion] The optimized section coal pillar width ( 8 m ) could realize the safe mining of 9106 working face.

Key words: Gob-side roadway; characteristics of destruction; coal pillar width; supporting pressure; plastic failure zone

CLC: