Disturbance characteristics of deep coal mass under the mining stress path

In order to derive the stress variation and failure characteristics of coal mass in front of working face under mining disturbance conditions,the discriminant index of the disturbance strength under different stress states is pro-posed through in-situ experiments and three-dimensional numerical simulation based on the geological condition of JI15-31030 working face of Coal Mine No. 12,Pingdingshan area,China. The stress evolution and the deformation characteristics of coal under mining stress path are obtained by taking the principal stress of coal mass as the interme-diate quantity,which makes a connection between the mining stress and failure characteristic in front of the working face. It can be shown from in-situ axial experiment that the mining stress of the coal in front of the working face is not a simple increase,but presents four states for the original rock stress,slow increase,sharp rise and sudden unloading. The 3D simulation results show there is a certain correlation between the side pressure coefficient and the disturbance state. According to the derived stress paths,the deformation law and plastic distribution state of coal samples under axi-al and triaxial mining stress state are reconstructed.