The Construction Process Simulation Of Subway Station And Optimization Of The Scheme

Being different from common tunnel construction,the Urban subway construction needto consider the effect on the surrounding environment and residents travel. Due to urbansubway construction in urban economic, so the building of the subway can’t influencethe development of business.because of the small demolition, less environmental pollution, and smalldisturbance to the ground transportation,the shallow tunneling method is widely used inthe underground rail.besed on Beijing metro line7shuangjing station as engineeringbackground,the paper use the large finite element software Ansys to simulate the smallpilot tunnel excavation and the main structure construction of the shallow tunnelingmethod. To the small pilot tunnel excavation, the paper simulate three schemes.the threeschemes are excavating firstly the above lag pilot tunnel in peap(schemeone),excavating firstly the above side pilot tunnel(scheme three),excavating firstly thebelow lag pilot tunnel in leap(scheme two).to the main structure construction,the papersimulate the excavating pilot tunnel,the construction of buckle arch,top beam,mainstructure.in contrasted with field monitoring data,the paper analysis the regular patternof the stress,the surrounding rock’s subsidence,the undergrand pipelines’subsidence.through analysis the following conclusions:1. Through the simulation and analysis of three ways,scheme one and three have thesame inpact of the surface subsidence on the longitudinal.their impact is the range of10m to18m at the back ofconstraints,scheme two has impact on the13m to20m ofconstraints. Scheme one and scheme three appear that the early stage has small surfacesubsidence,later the surface subsidence is biger.but the scheme two is contrary. based onthe three kinds of comparison and analyses of the settling tank curve, major difference of the scheme one and scheme three occurs in the first row of pilot tunnel excavationstage, scheme1and scheme2difference during the entire pilot tunnel construction.Through comparing the settlement trough width, finding the second scheme has bigersoil disturbance range than the rest of the two plans.2. Based on the comparison and analysis of13underground pipelines’ subsidenceduring the construction of three ways, finding that each line appeared largersubsidence.when pipeline is directly above the pilot tunnel,the pipeline will appearlarger subsidence.line6and line10of the13pipeline have the larger subsidence.3. Through the simulation of The main structure,we can find the surface subsidencemainly occurs in a small pilot tunnel construction and buckle arch construction,thevalue is81%of the final subsidence.after completion of construction, by analyzing thecurve of subsidence trough,finding that the final surface subsidence occurred around45m within the scope of the midline of the station.after completion of the main structureconstruction, underground pipelines have a larger subsidence, and beyond requirements,so underground pipeline need timely reinforcement and real-time monitoring.