Abstract: Aiming at the problems about prediction techniques for coal and gas outburst hazard, an in-depth study on dilatation energy of released gas from coal seam is conducted. Following the basic calculation methods of dilatation energy, based on the distribution rules of gas released from coal seam, the theoretical equations of dilatation energy of released gas from coal ribs and drilling boreholes have been derived respectively. In addition, by using the numerical simulation software of MATLAB, dilatation energy released from the drilling boreholes was further analyzed and calculated. The results show that there is a sharp decrease for the value of dilatation energy of released gas within the first 3 seconds in releasing time. The biggest factor affecting the energy is coal in-seam gas pressure; the second biggest factor is permeability coefficient; while the least one is the coefficient of gas content. Therefore, the dilatation energy of released gas from drilling boreholes can really reflect the instantaneous gas release ability of a coal seam. The measurement result of dilatation energy can be used as a predictor for the risk of coal outburst hazard when the coal in-seam gas pressure is determined in a field test.

Key words: dilatation energy of released gas from drilling boreholes, dilatation energy of released gas from coal ribs, numerical calculation, coal and gas outburst