Reasearch On The Ground Movement Law Due To Metro Station Driven With Enlarging Shield Tunnels

Combining with open-cut method or subsurface excavation method,subway station is built after the station passenger tunnel is perforated by shield tunneling. This is a very important and urgent research problem and has a wide application prospect in china. At the present, there is little research about ground movement law due to construction schemes of metro station driven with enlarging shield tunnels.Centering on the new construction method, the thesis takes Dongshankou station in Guangzhou as background and carried on the following research:(1) Analysing the research staturs of the home and abroad,the application of construction schemes of metro station driven with enlarging shield tunnels are introduced briefly, which provides the necessary theoretical basis for the following research.(2) Ground movement laws due to construction of metro station driven with enlarging shield tunnels are obtained, including stratum settlement (horizontal and vertical settlement), horizontal displacement and longitudinal displacement.meanwhile, influence degree caused by shield excavation and enlarging construction are selective analyzed, and when formation conditions change(such as IV grade surrounding rock,â…¤grade surrounding rock andâ…¥grade surrounding rock), what these laws are.(3) Taking the building which is located at the top of Dongshankou station as the engineering background, response law which surface structure acts on the ground and building deformation affected by ground movement are studied.Then,the interaction of building-soil-tunnel is analyse in depth, and got the Specific impact of two parameters(Tunnel depth:H; Horizontal distance between the tunnel and the building:L) on ground movement.(4) The four pre-reinforcement construction methods of construction of metro station driven with enlarging shield tunnels are optimized though large numbers of numerical simulation, and the optimum re-reinforcement construction method is proposed.(5) Ground settlement, convergence of tunnel construction gauge and vault crown settlement laws are obtained through analysis of large numbers of on-site monitoring datas. Meanwhile, these datas verified the numerical simulation results of chapter 3,4 and 5. Then, regression equations of convergence of tunnel construction gauge and vault crown settlement are obtained through regression analysis. As a result, the final convergence value and the vault subsidence are predicted and reasonable supporting time of second lining is gained. Research results of this thesis can be used in bustling urban areas which adopt this construction method, and favored the accumulation of experience of the construction of metro station and running tunnel.Moreover, scale merit of shield driving are created through increasing promoting distance of shield tunneling, which can satisfied the proliferation of subway construction and has major social. All these research results will have significant economic and environmental significance.