56 Study on Damage Developing Model of the Coal Rock with Non-Residual Stress

It is not applicable for the residual stress of coal-rock that the representation of coal rock damage model is in the form of damage strain relations with explicit function. In this paper, the stress and total strain power curve are drawn in loading and unloading condition by test. The relationship between the elastic modulus and damage energy consumption is analyzed with the plastic strain, it is identified that the rock of the damage energy with non-residual stress in the quasi-static process of the developing, and established the non-dimensional equations of the theoretical model. Finally, it shows that the damage developing is closed when the stress reduces to the residual stress; the residual stress can be determined by the nature of the damage coal rock.