Influencing Factors of Gas Seepage Flow in Advance Pressure Relief Area of a Mining Seam

Experimental schemes were designed for the entire evolution of the stress in the coal mass in front of the working face, and an experimental study on methane seepage from the coal mass in the advanced pressure relief area was conducted. Fitting functions for the permeability of the coal sample and its vertical stress were obtained by fitting the experimental data. A numerical calculation model was established with these fitting functions at different stages. The effect of mining height and mining depth on the law of methane seepage in the advanced pressure relief area was numerically simulated. With the increase of mining height and depth, the influence range of the advanced abutment pressure increased, and the peak position of the advanced abutment pressure moved away from the coal wall. However, the peak value of the advanced abutment pressure decreased constantly with the increase of mining height but increased with the increase of mining depth.