Study On The Spatial And Temporal Variation Of Surrounding Rock Stress Field In Deep Shaft Connection Of Coal Mine

Deep vertical shaft connection chambers of horsedoor is the throat of the mine shaft,located right in the heart of mine,has the design of cross section,long service life of adit,complex stress state,lane arrangement density and poor stability of repeated disturbance of surrounding rock during the construction,a series of important characteristics.The complex space three-dimensional structure,layout,adjacent cavern cross exists in the space,step-by-step excavation surrounding rock stress redistribution,will appear in the wall and ingate local surrounding rock stress concentration phenomenon,cause a large deformation of surrounding rock,seriously affect the normal production work.Due to the creep property of rock,the deformation of surrounding rock increases slowly during the process of excavation,and this deformation has a great impact on the supporting system.Therefore,it is of great significance to study the structure deformation of deep shaft connections and the repeated perturbations and creep deformation of rocks during construction.Based on the numerical simulation of Bo Jianghaizi mining area during the connection cavern group in step-by-step excavation of surrounding rock and rock creep characteristics on the basis of the group based on the cavern excavation supporting theory,rock rheological constitutive model theory,the analysis of the stress,deformation and plastic zone of change,it is concluded that:(1)pipe tao and ingate roadway excavation,stress release area overlap,making pipe bottom floor drum up a phenomenon,bottom stress value of 30.5 MPa.(2)the stress concentration phenomenon in the middle area of the tunnel group is relatively serious,and the stress relief zone is formed in 17 m of the surrounding rock in the upper part of the pipe road and the middle of the horsehead door and the upper part of the wellbore.(3)the distribution law of surrounding rock displacement and stress field distribution and the law of stress,strain and displacement of creep deformation are revealed.Due to the creep effect,the vertical displacement is increased from 93.39 mm to 925 mm.The creep curve of the key points of the model shows that the displacement change trend of the surrounding rock is gradually reduced and finally tends to be stable.