Numerical simulation for energy mechanism of underground dynamic disaster

Based on strain energy of coal or rock mass and expansion energy of methane,presented a unified energy equation for underground dynamic disaster analysis. Stress wave boundary condition added and fluid-stress coupling calculation applied,an numerical simulation model with energy calculation mode programmed in FLAC3D was set up to obtain energy distribution of roadway under different original methane pressures. Some deep dynamic phenomena with integrated characteristics of rock-burst and coal-and-methane burst was explained by the simulation results. The results indicate that different methane participation degrees result in different dynamic behaviors,methane participation degree may be represented by methane pressure or methane content; there is a critical range for methane pressure,when it is higher than the critical range,dynamic disaster takes on coal and methane burst’s characteristic,otherwise it takes on rock-burst’s characteristic; even under low methane pressure,methane expansion energy is equivalent to strain energy of coal or rock mass in order of magnitude,so methane can’t be ignored in researching rock-burst in coal seam with methane.