Study On Rock Burst Tendency And Instability Mechanism Of Deep Roadway In Huize Lead - Zinc Mine

Taking Huize Lead-Zinc Mine of8#ore-body for research background, the paper has discussed the rock bursting occurrence conditions of8#ore-body based on the engineering geology and the practical excavation case, while using numerical simulation, a finite element mechanics analysis method, build a three-dimensional numerical model for1391m level stage of8#ore-body and a roadway model of1405m level segment with stope structure parameters, blasting parameters, physical and mechanical parameters of rock and so on. Then it has successively revealed the mode of stress evolution and the instability mechanism of roadway surrounding rock, from static structure changes and dynamic disturbance of stress wave, by using stress criterion of rock burst and elastic deformation energy release rate.(1)According to stope ground-pressure activity from micro-seismic monitoring, successively taking the fifth segment of1391m level stage and the whole1391m level stage of8#ore-body as the research objects, it has obtained the mode of stress and displacement evolution of the surrounding rock through numerical calculation analysis based on the practical excavation case in chapter4. In addition, it has also made a rock burst prediction for the calculating range.(2)Taking the roadway in1405m level segment of1391m level stage as study object and taking elastic deformation energy release rate as criterion for surrounding rock instability, by stress wave dynamic disturbance, it has discussed the instability mechanism of roadway surrounding rock in chapter5, with shear strain increment, horizontal stress evolution, Changes of the plastic zones.(3) The result showed that, the mode of stress evolution in1391m level stage of8#ore-body is less affected by the sequence of excavation by steps, but it is sensitive to geologic structure and the shape of excavation section. Furthermore, the whole segmets of1391m level stage has a medium or strong rock burst tendency, the risk area is the zone near the corner of the excavation section, fault fracture zone or in the intercalation which has a gap of elastic modulus. Moreover, the frequent rock burst that occur in the hanging wall rock.(4) Stress concentration in surrounding rock may well exacerbate by mining disturbance under high stress level. It is more likely to failure occurs near the free face or among the zones with higher level initial energy reserve or high energy reserve in the dynamic disturbance process, and the area. The energy may release once more with low intensity in local area as aftershock of a natural earthquake.Build a large scale three-dimensional numerical model for Huize Lead-Zinc Mine of8#ore-body, the paper has revealed the mode of stress evolution with stepped excavation. While analysed the proneness and the mechanism of rock burst induced by stress redistribution based on stress criterion and elastic strain energy density. Then taking the roadway in1405m level segment as study object, it has discussed the instability mechanism of roadway surrounding rock under dynamic load. The research results can provide reference for the study and prediction of mining rock burst mechanism。...