Study On Key Construction Technology Of Deep Foundation Engineering For Crossing Existing Subway Station

Due to the various cities of geology and traffic situation different,Subway engineering construction will inevitably be the encounter different geological environment and traffic conditions,different construction methods are adopted for different urban construction environment.However,no matter what kind of construction environment,during the construction of the subway station,the excavation will cause disturbance to the stratum,and the deformation of ground surface and surrounding buildings.Therefore,proper construction methods and protective reinforcement measures should be taken to reduce the incidence rate of accidents,to protect the country and the people's daily lives and the economy is not affected by loss.So analysis on excavation construction and surrounding support of foundation pit engineering of subway station that cross existing lines from above has become an urgent need to address the problem.This paper to Xi'an Metro Line 4 station north station foundation pit excavation Because of the different geological and traffic conditions in each city,Subway engineering construction will inevitably be the encounter different geological environment and traffic conditions,different construction methods are adopted for different urban construction environment.However,no matter what kind of construction environment,during the construction of the subway station,the excavation will inevitably disturbed the strata,causing the deformation of the surface and surrounding structures.Therefore,proper construction methods and protective reinforcement measures should be taken to reduce the incidence rate of accidents,to protect the country and the people's daily lives and the economy is not affected by loss.So analysis on excavation construction and surrounding support of foundation pit engineering of subway station that cross existing lines from above has become an urgent need to address the problem.This pape takes the Xi'an city metro line four North Railway Station of the foundation pit excavation engineering construction as the background,through thenumerical simulation,analysis of cross lines subway station open cut construction of some key construction techniques and protective measures,and analysis of the Impact of the foundation pit excavation on the existing lines at the bottom.This paper mainly includes the following parts:(1)Study on the characteristics of retaining piles and commonly used in the form based on lots of literatures,by comparing and analyzing the economic value and the function of various support forms,the most suitable foundation pit supporting form suitable for the engineering practice is found out.(2)Through the finite difference software to simulate the actual effect of the water well around the foundation pit,and compared with the field monitoring data,the mechanism of the dewatering well is obtained,and it is used to guide the construction of the similar projects.(3)Through the finite difference software FLAC3 D numerical simulation No.4line north railway station foundation pit excavation process,analysis the change of displacement and stress of the structure under the existing line,and the results were compared with field monitoring data,it is concluded that the most suitable excavation method.