Abstract:
Deep rock mass exists in a kind of environment with high geostress,high temperature and high pressure. The influence of mining on it is complex than that on shallow rock. The strong disturbance to deep rock mass was analyzed systematically by combining the surrounding environment of deep rock mass and the disturbance characteristics of deep mining. Firstly,the cooperation between static and dynamic disturbance were examined. According to stress paths in deep mining,both the distribution of initial geostress state and that of disturbance stress state under different depth ranges were given,which reveals the complicated char-acteristics of stress paths in deep mining. Thereby a preliminary formula to calculate unloading velocity was proposed based on rock depth,mining method,rock gravity,residual stress and excavating speed. According to the type of dynamic disturbance and the law of stress wave propagation in deep mining,the characteristics of fluid pressure propagation in deep rock mass was pointed out. Thus it is inferred that the disturbance scope in deep rock mass is extended and the disturbance time is prolonged. Then the influence of disturb- ance was investigated according Disturbed State Concept (DSC). A disturbance function based on energy feature was defined by analyzing the energy storage,energy dissipation and energy release of deep rock mass,which would be a- dopted to build a unified constitutive model of deep rock mass based DSC. Such function can quantitatively describe the disturbance in deep rock mass. Lastly,the distribution of excavation disturbance zone in deep rock mass mining and the corresponding stress-strain state were described qualitatively. It is suggested to be divided into Initial Elastic Zone,Excavation Damaged Zone ( EDZ) and Excavation Fracture Zone,where Excavation Damaged Zone is divided into Inner Damage Zone,Plastic Disturbed Zone,and Unloading Damage Zone. A formula was given to calculate the size of Excavation Damaged Zone. Each pa-rameter in the formula was explained and the influence on them were dis- cussed. The study shows that the disturbance to rock mass in deep mining become more severe due to the high stress state of the deep rock mass and the complex multi-field coupling of multiphase environment,and thus the range of EDZ is increased significantly with more complex temporal and spatial evolution. The disturbance function based on DSC and the formula calculating EDZ size based on energy analysis can quantitatively describe the extent of disturbance in deep rock mass. They reflect the increase of disturbance stimulus in deep rock mass and the increase of disturbance effect in deep rock mass respectively.