The Numerical Simulation Analysis Of Excavation Supporting And Monitoring Technology About The Deep Foundation Pit In Tianjin

As one of the most rapidly developing cities in recent years,with the development of rail transit network the number of transfer stations becomes more and more biger in tianjin.Furthermore,multiline and point stereo crossing need the deeper foundationpit.Meanwhile,the design of the foundation pit is a kind of high synthetic systems combined with regional characteristics.The excavation depth of the foundation pit is becoming biger and biger,the theoretical research has been never interrupted of the foundation pit's design,construction and monitoring.This article use the lilou's deep foundation pit project which is situated in the eastern extension project of Tianjin Metro Line 1.Analysing of site monitoring data in the whole excavation process of the deep foundation pit and using FLAC-3D for numerical simulation of the whole construction process of the foundation pit.Comparing simulation results with the measured data,and making a further study about the critical issues in the process of the metro deep foundation pit excavation.Reading the engineering geological exploration report carefully.Learning more about the site profile,stratigraphic and lithologic characteristics,meteorological and hydrological conditionsconditions,foundation pit supporting scheme,supporting system and the detailed construction procedure of the project.Analyzing the horizontal and vertical displacement in the top of diaphragm walls,the horizontal displacement of the wall,the subsidence deformation of surface,supporting axial force changes,and the measured data on the spot.We can research the actual change of the surrounding environment in the process of foundation pit excavation and supporting.Simultaneously,it can accumulate experience of similar projects in the same region.Study the finite element theory,the constitutive model of soil and numerical,the numerical analysis method for Foundation pit excavation carefully.Establishing a three-dimensional numerical analysis model of foundation pit by FLAC-3D.Analyzing each period of excavation.Learning the changes of the foundation pit in different excavation stages through the simulation analysis of foundation pit.Its main content includes the top of diaphragm wall'horzontal and vertical displacement,vertical displacement of the diaphragm walls,lateral displacement of the long side and short side of diaphragm walls,surface subsidencedeformation,support axial force change and the changing rule of upheaval in the bottom.Besides,the simulation results and the measured data were comparative analysis to verify the rationality and applicability of the model in this paper.New basis of the numerical simulation of subway engineering in this region can be provided.