DOI: 10.11799/ce202504014
Air leakage law of fully mechanized caving face of gob-side entry retaining in lower sub-level of extra-thick coal seam
SONG Zhihong
LI Xuejun
GUO Jun
WANG Lei
DU Wentao
JI Xinyu
ZHANG Kefeng
Abstract：With the increase of mining depth and cost,gob-side entry retaining technology is widely used in thick coal seam mining,which reduces the mining cost and improves the recovery rate of coal resources.However,due to the roof weighting,the coal pillars on the side of the gob-side entry retaining are prone to cracks,resulting in serious hidden dangers of air leakage in the goaf.Therefore,we took the No.8521 working face of Chenjiagou Coal Mine as the research object,and applied theoretical analysis,field air leakage test and numerical simulation to analyze the distribution characteristics of air leakage channels in goaf of gob-side entry retaining under W-type ventilation mode,and grasped the evolution law of key air leakage areas.The results show that the main air leakage channel is 1-3#flexible formwork wall when the fully mechanized caving face of gob-side entry retaining advanced to 54 m,and the range of air leakage flow field is 5.57～71.46 m/min.When the working face advanced to 126 m,the main air leakage channel is 3-18#flexible formwork wall,and the range of air leakage flow field is 4..11～52.90 m/min.The air leakage rate decreases gradually in the range of 0～80 m along the strike in the deep goaf.In the range of 20 m in the shallow goaf,the overall air leakage rate is exponentially related to the distance from the working face.The research results can provide theoretical guidance for the prevention and control of coal spontaneous combustion in gob-side entry retaining.
Keywords：coal spontaneous combustionextra-thick coal seamgob-side entry retainingdetermination of air leakageair leakage law
Publication Date：2025-04-20
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：8( 93-100 )