Creep Laws of Coal Containing Coalbed Methane (Gas) at Different Temperature

In order to explore the creep law of gas-saturated coal, at first, the axial loading stress of the creep test of gas-saturated coal is determined by using the briquette coal to carry out the complete stress-strain loading experiment of the gas-saturated coal under different temperature. Then, the creep experiments are carried out by keeping axial compression, confining pressure and gas pressure constant to measure the dynamic curves between axial, radial, body strain and time of the gas-saturated coal. The results show that the axial strain-time curve, the radial strain-time curve and the body strain-time curve are increased with the increase of temperature during the creep of the gas-saturated at different temperature. Various strain-time curves have intersections in different levels. The initial instantaneous strain and attenuation rate of various strain are different at different temperature. All kinds of strain-time curves have obvious primary and steady creep, but the accelerated creep is not；in the whole creep process of each temperature, the body strain is dominated by axial compressive strain. The higher the temperature, the greater the axial compressive strain in the body strain. At last, the creep strain expression of gas-saturated coal is established. Calculation shows that as the temperature increases, the elasticity of gas-saturated coal decreases, the viscosity increases, and the gas-saturated coal is more easily compressed.