EXPERIMENTAL RESEARCH ON EFFECT OF GEOSTRESS ON OUTBURST COAL′S GAS SEEPAGE

Based on the typical coal and gas outburst of Datong mine in Songzao,the experiment of outburst coal′s gas seepage under stationary gas pressure and different confining pressures is conducted by MTS815 mechanical testing machine and self-developed servo-controlled triaxial load system. The results show that the seepage velocity of outburst coal′s specimen drops at first and rises later with increasing axial stress,but decreases and keeps stable after peak stress. The seepage velocity after peak stress decreases with the increase of confining pressure,and keeps stable after the confining pressure reaches 4 MPa. The complete process equation of seepage velocity-axial stress is built. The relationship curve of seepage velocity-strain,which reflects the change of gas gradient,is derived.