The change and distribution law of outburst coal seam permeability induced by drilling an extra-thin protective coal seam
LIU Hai-bo
CHENG Yuan-ping
SONG Jian-cheng
SHANG Zheng-jie
Abstract：Similarity simulations and field tests were used to investigate the change in seam permeability and the permeability distribution rule of the protected coal seam before and after pressure relief in order to analyze the pressurerelief protection effect of extra-thin protective coal seam mining. The similarity simulation tests show that the protected coal seam undergoes expansion deformation in the stress-relaxed area after the extra-thin coal seam is drilled. The permeability coefficient of the protected coal seam is increased from 3.80 to 7. 11 m~2/(Mpa~2· d) ,and after the overlying coal-rock mass has become stable,the permeability coefficient of the coal seam decreases to 5.61 m~2/(Mpa~2 · d) because of stress recovery in the coal-rock mass. The protected coal seam permeability in a certain extent before the open-off cut and after the stopping line is higher than it in the middle of the goaf. With the protected coal seam being gradually compacted, the seam permeability decreases. In order to achieve the optimal effect of gas drainage, the extrathin protective coal seam drilling combined with pressure relief gas drainage of the protected coal seam must be adopted. Field tests show that the permeability coefficient of the protected coal seam increases from 0. 047 to 18. 928 m~2/(Mpa~2· d) ,an increase of 403 times.
Keywords：the extra-thin protective coal seamthe protected coal seamseam permeabilitysimilar simulationpressure relief
Publication Date：2010-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：6( 411-416 )