Deformation Monitoring And Numerical Simulation Of Deep Foundation Pit Excavation In Subway Station

With the rapid development of city subway in twenty-first Century,deep foundation pit of metro construction and support has become a difficult problem in the construction industry in the present era,which becomes the study object for experts and scholars in the construction industry of the deep excavation test section.Taking the three road station of Hangzhou Metro Line 2 Station Road as engineering background,this paper this paper analyzes and studies the deformation of deep excavation by means of the combination of field monitoring data analysis and ABAQUS finite element simulation.The main works are as follows:(1)The deep foundation pit monitoring scheme of Hangzhou construction of three road station of metro station affiliated structure was systematically introduced and analyze the structure of deep foundation pit horizontal displacement,axial force and the construction monitoring data of outer protective were studied through the comprehensive arrangement analysis in order to probe the change law of the horizontal displacement of the pile and the surface subsidence with the excavation depth of deepening.(2)This paper introduced the finite element simulation of deep excavation,which made clear calculation theory for deep foundation pit excavation simulation.(3)Combined with the construction of three road station project,threedimensional numerical simulation of the deep foundation pit was simulated by means of ABAQUS,and the unit selection in the process of the deep foundation pit excavation simulation,model building,parameters determination and boundary conditions were introduced.After the analysis of the construction of excavation sequence and the simulation of the whole excavation process,the indexes such as the deformation value of excavation retaining structure in each stage,the pit soil surface settlement and foundation pit heave value were obtained.Meanwhile,the finite element simulation results agreed well with the monitoring results,which shown the validity of the finite element models and parameters selection.Then,the influences of foundation pit support structure stiffness,support stiffness and insertion ratio on the foundation pit deformation were analyzed by use of single factor transformation.Besides,the simulation processes and results will have the certain reference value for the same type of deep foundation pit structure excavation.