Stress Analysis on Coal Gas Adsorption and Emission

Abstract：In order to study the mechanics features of coal during the gas adsorption and emission process,a experiment platform of the coal gas dynamical effect simulation system was applied to establish a coal gas adsorption and emission physical experiment model.A monitoring and measurement was conducted on the coal total stress,gas pressure,gas emission velocity and other parameters of coal during the gas adsorption and emission process.The simulation experiment results showed that as for the coal in the rigid surrounding rocks,when the coal gas converted from a free state to an adsorption state,the coal total stress would be slightly low and the void pressure and the effective stress would be reduced and increased with the time and individually according to the logarithmic law.During the coal gas emission period,the gas pressure and the coal total stress would be reduced with the time and according to the negative index law,the effective stress would be slightly reduced with the time and the gas emission velocity would be reduced with the time and according to the logarithmic law.The study achievements would have certain reference values to the prevention and control of the mine gas dynamic disaster and to the theoretical study on the coal bed methane development technology.