Numerical Simulation Analysis on Stability During Excavation of Deep and Large Vertical Shafts
This paper presents a numerical simulation analysis of the disturbance effect on the surrounding rocks and the initial support forces caused by the shaft construction,based on the Chunmu mountain tunnel ventilation shaft project of the Zhitong highway.The most hazardous areas of the surrounding rock in the shaft excavation and the reasonableness of the initial support parameters are investigated.According to the analysis results,corresponding reinforcement or protection measures are proposed.The results show that the shaft construction caused less disturbance to the surrounding rock and no obvious plastic zone in the surrounding rock,revealing a certain stability of the surrounding rock after excavation and application of the initial support.As the excavation depth increases,the maximum stress in the rock increases,reaching a maximum value of 3.36 MPa at the bottom of the shaft,the surface settlement curve shows an obvious V-shaped feature,with a large settlement in the middle and a smaller settlement the further away from the central excavation area.The change of stress in the transition zone of the different properties of the surrounding rocks will occur suddenly,and the frequency of support and monitoring of the transition zone of the surrounding rocks should be enhanced in practice.
highway tunnelsshaft constructionsurrounding rock disturbanceinitial supportnumerical simulation
万方数据
维普
