Uniaxial Loading Statistical Damage Constitutive Model for Coal and Rock

In order to study the laws of damage evolution of coal and rock under uniaxial loading, the uniaxial loading test of coal and rock was done, and we obtained the stress strain curve and hoop to axial strain curve of coal and rock. The experimental results show that the hoop strain rate increases with the increase of axial strain, which presents nonlinear law in the loading process of coal and rock, and the increase rate reaches the maximum value when the coal is loaded into softening stage, which reflects the generation and development of internal crack of coal and rock at macro level, and conforms with the damage evolution law of the coal. So defining the damage variable as a function of crack volume, assuming the increase volume of crack conforms to Weibull statistical law, constructing a statistical damage constitutive model of coal, comparing with the experimental results, it verifies the correctness of the model.