THE IMPACT MECHANICAL PROPERTIES OF COAL CONTAINING GAS1)

In order to obtain the impact mechanical properties of coal containing gas, the mechanical properties of coal samples with adsorption gas pressures of 0 MPa, 2 MPa, 4 MPa and 6 MPa are determined by the uniaxial compression test method. The results show that the compressive strength, the elastic modulus and the impact energy index of coal samples decrease linearly and the peak strain increases linearly with the increase of the adsorbed gas pressure. With the increase of the adsorbed gas pressure, the failure type of the coal body changes from brittleness to ductility, and the portion of the separation failure portion is enhanced. The adsorbed gas accelerates the process of instability and failure of the coal body, and makes the coal and rock gas dynamic disaster change from the rock burst dominated type to the coal and gas outburst dominated type.