In China, coal-gas outburst is seriously affecting safety of the coal mine. To improve the safety status of underground coal mining, this work investigated the evolution process and occurrence mechanism of coal-gas outburst under the coupling action of stress and gas. Results show that increasing either gas pressure or in-situ stress can make coal destroy and destabilize, and the contribution of gas pressure to coal failure is twice that of in-situ stress. In ultradeep coal mining, coal-gas outburst may occur even under the condition of low gas pressure due to large in-situ stress. Moreover, the larger the mining depth is, the lower the gas index is required for disaster occurrence. The results have certain guiding significance for coal energy mining and the control of coal-gas outburst in deep coal mining.
A model of one-dimensional coal gas outburst wave