Abstract: Gas parameters variation has significant influence on the gas disaster prevention in coal mines. In this paper, the initial velocity of gas emission, abutment pressure ahead of the face, gas emission and permeability coefficient in coal seam, et al, were analyzed by the theoretical analysis and numerical simulation. The results show that there are similar or opposite variation regularity among these parameters, which are the combinations of S-shaped curve and inverted S-shaped curve associated to the distance x or time t. Meanwhile, permeability coefficient curve with distance, as well as gas pressure and abutment pressure with distance, all present not exactly symmetrical characteristics. Thus, the variation regularity of parameters can be ascertained with specific coal mine conditions. The research results can provide theoretical guidance to the prevention and control of gas disaster in coal mines.

Key words: gas parameter, variation regularity, S-type, inverted S-type