Experiment study of mechanical and gas seepage characteristics of containing-gas coal in the process of unloading confining pressure

By using triaxial stress thermal-hydro-mechanical coal containing gas permeameter, mechanical and gas seepage characteristics is researched under different confining pressure, different initial axial stress and different unloading speed of confining pressure, the results shows that the increasing of unloading speed of confining pressure and the initial axial stress will shorten the time of the time of axial stress platform, From the aspect of gas permeation, the increasing of unloading speed of confining pressure and intial axial stress will accelerate the increasing of permeability, therefore, reasonable arrangement of roadway and method which can reduce the supporting stress should be proceed to preventing the outburst accident.