Possible Effect of Main Roof Settlement on Outburst Hazard in Case of Gas Hydrate Dissociation during Coal Mining

Abstract

The results of physical modeling of geomechanical processes in outer zones of coal beds with the main roof caveable with difficulty. The scope of the modeling embraces the inlfuence seams on gas release by gas temperature and pressure variation during stage-wise outlet of gas from a pressure bomb, which simulates cyclical mechanical impact on a coal seam in the zones of a gas pocket. It is found that the low-frequency (2.0–4.5 Hz) attenuating vibrations generated in the main roof can induce both secondary rock mass disintegration as well as methane desorption and decomposition of gas hydrates (if present) accompanied by an increases in gas pressure and in number of gas-dynamic events in outer zones of coal beds.