Effect Of Foundation Pit Excavation On Deformation Of Shield Tunnel With 5.9m Inner Diameter

With the rapid development of Metro Engineering in the city,the economic benefits of Metro itself drive the construction of nearby buildings.The construction of buildings will inevitably produce many foundation pit projects,and the excavation of foundation pits will inevitably have a certain impact on the deformation of adjacent Metro tunnels,while the requirements for deformation of metro tunnels are very strict,which will have an impact on the safe operation of Metro tunnels.At present,there are relatively few studies on the influence of foundation pit excavation on the deformation of adjacent 5.9m inner diameter shield tunnels.In this paper,the finite element software MIDAS/GTS is used to study the influence of foundation pit excavation on the deformation of adjacent 5.9m inner diameter shield tunnels by establishing a threedimensional numerical model.(1)Introduce the research background of this paper,summarize the research status of the influence of foundation pit excavation on the deformation of metro tunnel at home and abroad,and put forward the main research contents and problems to be solved.(2)Introduce the factors causing the deformation of shield tunnel,summarize the laws of transverse and longitudinal deformation of shield tunnel,and analyze the calculation method of equivalent stiffness of shield tunnel.(3)Using the finite element software MIDAS/GTS,the whole excavation process of the adjacent 5.9m inner diameter shield tunnel is simulated,and the characteristics of the lateral and longitudinal deformation of the adjacent 5.9m inner diameter shield tunnel are analyzed.The results are compared with the numerical simulation results of the 5.5m inner diameter shield tunnel.(4)From the aspects of excavation depth of foundation pit,horizontal distance of foundation pit,plane dimension of foundation pit,buried depth of shield tunnel,equivalent stiffness of tunnel and engineering geological conditions,the influence law of each influencing factor on deformation of adjacent 5.9m inner diameter metro tunnel is studied.