CHEN X X, WANG D D.Mechanism and surrounding rock control of roof cutting and pressure relief in thick-hard roof roadways with gob-side entry driving using small coal pillars[J].Journal of Henan Polytechnic University(Natural Science) ,2026,45(2):97-106.

doi:10.16186/j.cnki.1673-9787.2024110063

Received:2025/04/30

Revised:2025/06/08

Published:2026/01/28

Mechanism and surrounding rock control of roof cutting and pressure relief in thick-hard roof roadways with gob-side entry driving using small coal pillars

Chen Xiaoxiang1,2, Wang Dongdong1

1.School of Energy Science and Engineering， Henan Polytechnic University， Jiaozuo  454003， Henan， China；2.Collaborative Innovation Center of Coal Safety and Clean High Efficiency Utilization， Jiaozuo  454003， Henan， China

Abstract: Objectives To investigate the mechanism of roof cutting and pressure relief in roadways with immediately overlying thick-hard roof strata adjacent to working faces， and to determine the rational width of small coal pillars for gob-side entry driving. Methods Taking the return air roadway of the 15107 working face in the No. 15 coal seam of Tongbao Coal Mine as the study object， theoretical calculations， numerical simulations， and on-site industrial tests were conducted to analyze the stress distribution characteristics of surrounding rock during gob-side entry driving with small coal pillars under conditions of roof cutting and pressure relief in immediately overlying thick-hard roof strata.  Results The results show that a roof-cutting height of 21 m in the transportation roadway of the 15106 working face can effectively cut off the overlying thick-hard roof strata， reducing the lateral cantilever length of the roof. The theoretically determined reasonable width of the small coal pillar for gob-side entry driving ranges from 4.807 to 5.225 m. After roof cutting， the surrounding rock stress in the solid coal on the right side of the goaf decreases significantly， resulting in a more moderate stress environment for the gob-side entry. Roof cutting also effectively reduces the peak vertical stress within the small coal pillar. Numerical simulation results for coal pillar widths of 3， 5， 7， and 9 m indicate that increasing the pillar width from 3 m to 5 m leads to an increase of up to 166.31% in the peak vertical stress on the roof surface of the coal pillar， whereas increasing the width from 5 m to 9 m results in peak stress variations of less than 27.32%.  Conclusions Field tests demonstrate that leaving a 5-m-wide small coal pillar and implementing appropriate support measures for the 15107 return air roadway can limit the surrounding rock deformation to less than 200 mm under the influence of working-face mining. Deep-hole pre-splitting blasting for roof cutting and pressure relief exhibits a significant control effect， satisfying the safety production requirements of the 15107 working face and providing a reference for coal mine production under similar geological conditions.

Key words: thick-hard roof strata; small coal pillar; roof cutting and pressure relief; gob-side entry driving; surrounding rock control