Research on roadway layout and surrounding rock control technology under influence of coal pillars in overlying coal seam goaf

Ge Fei

doi:10.19896/j.cnki.mtkj.2025.05.029

Abstract：In response to the problem of influence of overlying coal seam goaf and coal pillars on the stability of roadway,the No.30503 return airway of a certain mine was taken as the research object.Numerical simulation and on-site observation methods were used to an-alyze the stress distribution and failure law of roadway surrounding rock under the influence of coal pillars in overlying coal seam goaf,and the corresponding roadway layout and surrounding rock control technology were explored.The results indicate that when the angle between the central axis of mining roadway and the centerline of coal pillar is 0°,the stress concentration factors on both sides and the top of roadway are the lowest.As the distance between the roadway position and the centerline of upper coal pillar increases,the maxi-mum and minimum principal stress directions of roadway will deviate,and their magnitude will approach the stress of original rock.Mo-reover,the lateral pressure coefficient gradually increases,and the plastic zone will also deviate accordingly.Taking into account factors such as supporting,maintenance,and construction,the No.30503 return air roadway was horizontally arranged 25 meters below the coal pillar in the No.2 coal seam.The mining pressure in the experimental section of roadway was slightly reduced compared to before opti-mization.A combined supporting method of"rockbolt+anchor cable+steel mesh+spray"was adopted for targeted parameter design,sig-nificantly improving the stability of roadway.