Characteristics of Methane Explosion and Dynamic Response of Rock Mass in an H-Type Roadway with Different Ignition Sources

Methane explosion is an undesired incident in the coal mining industry. Its high pressure wave can cause damage to the rock mass. This study numerically investigated the flame and wave transport characteristics of methane explosion with ignition sources at three different locations, and the corresponding dynamic response of the rock masses was discussed. The results showed that the flame propagation time is shortest when the ignition position is located at the center of the H-type roadway structure and the maximum overpressure decreases as the ignition position deviates from the center of the H-type roadway structure. When the ignition point is located at the center of the H-type roadway structure, the smallest total deformation of rock mass shows up with the highest maximum overpressure. In contrast, the largest total deformation appears when the ignition point is most away from the center due to the asymmetric distribution of the gas pressure exerted on both sidewalls of the rock masses. This work may provide insights into the understanding of deflagration propagation and the dynamic evolution of stresses under complex conditions.