Research on the stability analysis and control technology of coal wall in the working face of large mining heights
FU Baojie
CHEN Xiaodong
Abstract：Aiming at the situation that"the large breaking step of the roof slab directly overlying thick and hard sandstone is easy to cause coal-rock dynamic disasters such as coal wall ganging",this paper studies the min-ing process of 14121 working face in Zhangji mine,which has thick and hard sandstone as the roof slab,and combines with theoretical analyses to find out the influencing factors of the coal wall ganging,and determines the reasonable breaking step.Adopting pre-cracking blasting to force the roof release programme,simulating the effect of roof cutting with UDEC software,comparing the stress concentration at the coal wall before and af-ter cutting the roof by pre-cracking blasting at different breaking steps and the damage characteristics of the coal body in the plastic zone.The results show that:compared with 25m roof breaking step,15m roof breaking step makes the peak over-supporting stress in front of the coal wall decrease by 20.1%,but the bearing capac-ity of the coal wall increases by 121%,the maximum horizontal displacement of the coal wall decreases by 35.3%,and the range of the plastic zone of the coal wall decreases by 30%,thus reducing the occurrence of the accident of the coal wall flake gangs,and guaranteeing the safety of the large-height working face.
Keywords：big harvestingcoal wall gangpre-crack blasting cut topconcentrated stress
Publication Date：2023-12-28
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：8( 8-15 )