Numerical modeling of gas extraction by relief pressure from a long-distance

The coal seam movement of Panyi coal mine, as well as its collapse process, gas permeability evolution induced by excavation of the underplayed coal seam are simulated, using newly developed F-RFPA2D code, which can simulate the strata fracturing, caving process, and gas permeability evolution induced by excavation of the underplayed coal seam. This research reveals the movement regular of the gas drainage. The results are well tallied with the field data, being practical and reliable to analyze the engineering problems such as gas permeability evolution and gas delivery induced by mining.