Study on failure and instability mechanism of roof in room-and-pillar goaf
HE Zhiwei
ZHU Lei
LIU Chengyong
GU Wenzhe
XU Jianfei
SONG Tianqi
LIU Zhicheng
ZHANG Peng
Abstract：In view of the disaster caused by the instability of room-and-pillar goaf,taking the coal pillar left over from a pillar goaf in Yulin as the research background,the roof instability mechanism of room-and-pillar goaf is studied by means of theoretical analysis,physical similarity simulation,numerical analysis and so on.The research results show that the safety factor of the stability of the re-maining coal pillar in the mine goaf is 1.54,considering the creep of the coal pillar under the long-term roof load,the large area in-stability will occur in the end.The influencing factors of the failure and instability of the coal pillar in the room-pillar goaf include five factors,such as physical and mechanical properties of coal,weathering,mining mode,water erosion,creep and so on.The fail-ure law of the catastrophic evolution of roof in room-and-pillar goaf is from point to surface,and the roof from failure to instability is divided into four stages:preliminary failure stage,failure expansion stage,failure aggravation stage and complete instability stage.When the goaf is completely unstable,the peak stress of coal pillar is 15.08 MPa,the stress concentration factor is 3.92,and the roof subsidence displacement is 392.44 mm.
Keywords：room-and-pillar goafroof disasterremaining coal pillarstability of coal pillarnumerical simulation
Publication Date：2024-04-20
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：12( 152-163 )