Application and Study on Permeability Improvement Effect by Pressure Relief in Mining-induced Coal Body
WANG Kai
ZHENG Ji yu
XIA Wei
LI Peng
LI Cong
Abstract：In order to study the coal body permeability improvement effect by pressure relief ahead of mining face and improve gas drainage quantity,the paper analyzed the correlation of coal body deformation failure and permeability change ahead of mining face.In pressure relief zone ahead of mining face,coal body slip failure occurred,which had marked expansion and permeability improvement effect.The authors tested the change laws of coal body stress ahead of working face and boreholes gas flow with advance of the face in site,the distribution scope of the abutment pressure zone and pressure relief zone were determined.In pressure relief zone,because coal permeability increased, the average borehole gas flow increased by 2~3 times.Based on coal permeability increasing effect by pressure relief ahead of coal face,pre-drainage boreholes pressure relief gas drainage quantity calculation formula with different angles were achieved on the basis of varied borehole failure distance and pressure relief zone width.The results showed that the larger the borehole angle was,the bigger pressure relief gas drainage quantity was.In combination with geological conditions of No.N2015 coal face in some mine to calculate,borehole angle could reach the max value 21.4°,compared with original coal body vertical boreholes,single pressure relief borehole gas drainage could improve 978.5 m3 ,which could effectively improve the coal seam gas drainage rate.
Keywords：gas drainagepermeability improvement by pressure reliefmining-induced coal bodyboreholes layoutcoal body permeability
Publication Date：2014-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：6( 65-70 )