Study on the Coupling Effect of Stress Field and Gas Field in Surrounding Rock of Stope and Gas Migration Law

In the process of working face mining, permeability coal seam and crack evolution characteristics overlying strata are very important for efficient gas drainage. this study, distribution stress field in their relations analyzed mainly by 3DEC numerical simulation. Furthermore, combined with on-site measurement stress, pressure, seepage front before after coupling effect law migration deeply explored. The results show that changing trend pressure is controlled change face, increase also increase. peak position farthest from wall, about 22.5~25 m, followed seepage. When rock mass increases, increases decreases. fracture zone along tailgate side generally greater than those on headgate side, but opposite. Mining cracks separation provide a good channel space accumulation. Along strike tendency concentrated above roof tailgate, respectively. Based this, directional borehole drainage technology layout scheme fractured put forward, which effectively reduce concentration 30~36%.