Numerical Simulation of Gas Accumulation Area Characteristics in Top-coal Caving Region

The phenomenon is increasingly prominent that the roof caving excesses the normal roadway height or working face design height in the process of roadway excavation and working face mining.It not only affects the project progress, but it will also cause gas accumulation in top-coal caving region of inlet wind groove for high gas coal mine. On this basis, the numerical simulation is carried out for the gas accumulation of top-coal caving region, the top-coal caving region is divided into three regions including the wind flow influence area, the annular turbulent area, no wind area. The results show that the gas accumulation will not occur in the wind flow influence area; there is less gas movement in the center of annular turbulent area and the gas concentration is low; the gas accumulation mainly happens in no wind area, it is the key area of gas control.