Study On Design Of Foundation Pit Support Structure And Deformation Simulation Of Subway Station

With the rapid development of China’s economy and urbanization,a large number of people have flocked to the city,the number of cars has increased year by year,and the traffic congestion problem has appeared in major cities.The subway system has high transport efficiency,does not occupy the space on the ground,and has little pollution to the environment.China has more than and 20 cities built and began operating the subway,as well as more cities are building subway projects.The construction of the subway station is mainly using the open excavation method,and the deep foundation pit engineering is an important part of the construction of the subway station.This paper takes the Shenzhen City Metro Line 9 Yuanling station as engineering example,analysis of factors affecting the deformation of foundation pit.First,the use of "Lizheng 7"software "of the diaphragm wall and support" and "bored pile with support two support design in the preliminary design,support design dimensions,supporting structure internal force and reinforcement step diagrams etc..Second,the finite difference software FLAC3 D is used to simulate the excavation and support of foundation pit with different simulation schemes for the two support schemes.On the basis of the simulation,the deformation law of the foundation,the lateral displacement of the foundation pit and the settlement of the ground surface are analyzed,and the two schemes are compared with the design results.Third,with the support of the simulation method discussed retaining structure of the embedded depth,support stiffness,retaining structural stiffness,support longitudinal spacing and the inner support number of influence factors on the deformation of foundation pit excavation by adjusting parameters.The Mohr-Kulun model can simulate the mechanical behavior of soil well,and can be used to calculate the deformation of foundation pit.There are spatial effects at the end of the foundation pit,which can limit the deformation of the foundation and the lateral displacement of the surrounding soil.In the case of engineering,the foundation pit is located in the soil with good geological condition,and the horizontal lateral displacement curve and the surface settlement curve of the retaining structure are parabolic.The basement is located in the rock with good geological condition,and the influence of each parameter on the vertical displacement of the foundation is relatively small.In the analysis of the influence of the design parameters on the deformation of the foundation pit,considering the experience of the project,the safety and convenience of construction,the economic cost of the project and other factors,the value of the design parameters used in the design is reasonable.Through the design and numerical simulation of subway station,this paper analyzes theinfluence of various factors on the deformation of foundation pit.