A study of the principles and methods of quick validation of the outburst-prevention effect in the process of coal uncovering

Experiments have been conducted under different gas injection rates and gas pressures. CO2 and N2 gases have been used as injection media. After 50 test runs, 48 sets of valid data have been collected. The results suggested that the IVGEB value is approximately proportional to the gas pressure: the higher the gas pressure, the larger the IVGEB value. Furthermore, based on the relationship of the initial expansion energy of released gas (IEERG), which is another forecast indicator and gas pressure, the weak outburst pressure P1 and intense outburst pressure P2 of each coal sample could be calculated because the critical values of IEERG were 42.98 and 103.8 mJ/g, respectively. Thus, the IVGEB critical value of weak outburst and intense outburst could be obtained by applying a relation formula between IVGEB and gas pressure. The obtained IVGEB critical value of weak outburst and intense outburst were 39.69 L and 93.32 L, respectively. This approach might provide a possible method to validate the outburst-prevention effect quickly in the process of uncovering coal in crosscuts within deep mines.