Study On Design And Deformation Control Of Large And Deep Foundation Pit Support For Underground Railway Station

Currently, high-speed passenger line underground station design and construction in China was still in the initial exploratory stage, with the development of high-speed railway, the large and deep excavation projects necessarily required further study.The thesis firstly reviewed the domestic and international development and summaries the structural characteristics of lager and deep foundation pit for underground railway station. Based on the plan of the Jialing River Bridge, The deep foundation project which located at Shuangliu Airport Station of CMLZQ-5 bid on Chengdu-Mianyang-Leshan passenger line was set as the background. The excavation and support design of deep foundation and the soil reinforcement measures between it and oblique arch pile foundation were researched. The author also calculated the earth pressure and horizontal brace force and checked the stability of the envelope.Plaxis2D was applied to simulate the retaining state and excavation of the deep foundation pit. Compared MC model with HS model, the law of horizontal deformation, the position of maximum horizontal displacement, and Mechanical Characteristics for its retaining structure and effects of oblique arch foundation were analyzed. The influence the excavation and oblique arch foundation made on catering of food companies.On the basis of original design, the influence on deformation by changing pile diameter, interval of pile, and prestress of steel supports was studied. Then, in corresponding, bring up the measures for retaining system's optimization design.The retaining scheme and the monitoring plan of the foundation pit were given in this paper. After distilling and collation the data of the pile-wall's deformation and stress, the axis force of the steeled support. Comparing with the numerical simulation data, found that the result from finite element software consistent well with the measured data. The result indicated that the horizontal displacement of the pile-wall could be the important evaluation index which showed the safety state of the retaining construction.The research findings in article provided some theoretical basis for theoretical analysis, optimization design and construction of the retaining in deep foundation pit.