Dimensional Analysis of Coal and Gas Outburst and its Application

The process of coal and gas outburst was regarded as the sequential and alternating occurrence of three phenomena: the quasi-static deformation and failure of coal and rock system, the spalling and crushing of gaseous coal, and the flow of chipping coal and gas, some similarity criterions were obtained corresponding to the three phenomena through dimensional analysis method. According to these similarity criterions, a conclusion be made that the size reduced similar model of outburst can't be completely similar to in situ outburst, to improve the similarity, the model must have the biggest size it can get. The similarity criterions were also used to explain some outburst phenomena, it revealed the coupling effect of various outburst influencing factors, and then demonstrated some unreasonable factors of China's current outburst identification method for coal bed and coal mine.