The Research Of Effect On The Side Of The Bridge Piles Passed By Shallow Tunneling Construction Of Urban Subway

With the rapid development of urban economy, the rapid increase in urbanpopulation resulted in crowded urban ground transportation. In order to alleviate orsolve the problem fundamentally, the development of urban underground space isimperative, the convenient public transport subway was born at the right moment.However, in the construction process of the subway tunnel, the tunnel will passthrough dense buildings inevitably in the city, and that will threaten the security of thebuilding, it has become the main problem how to reduce the influence of tunnelexcavation on adjacent buildings.Among the tunnel construction methods, shallow mining method has become themain construction method of the city subway tunnel construction due to the advantageof less impact on the ground transportation and the surrounding environment, and willcontinue to play a major role in the construction of urban subway tunnel, but thetunnel construction not only disturb the surrounding rock and soil generated byshallow mining method, but also cause land subsidence and in deformation ofadjacent buildings, finally threaten the security of the buildings.This paper is based on the project that the14th Beijing Subway tunnel passthough the side of Lotus River Bridge, that simulate the process of the tunnel throughthe bridge by the use of Midas/GTS finite element analysis software and analysis theeffect of the bridge piles on the two cross section. It is concluded that the deformationlaw of bridge piles, and analyzed the effect of the bridge piles under normalexcavation state and excavation state after reinforcement grouting, else summarize thesubsidence distribution of the bridge piles under different construction process, andput forward that it is necessary to grout reinforcement when tunnel through the bridgepiles, the author hopes that it can provide some references for similar acrossengineering. The following is the research content of this article:（1）Numerical simulation, it simulated two different sections of Lotus Riverbridge by using Midas/GTS finite element analysis software, and predicted settlement and horizontal displacement of the bridge piles on the two different sections,compared to the effect of the settlement for the length of bridge piles, as well as thegeneral law of the bridge piles deformation under normal excavation state andexcavation state after reinforcement grouting bridge pile.（2）Field measurement, it can laid main monitoring points centre on the twosection at the construction site, and took the data of the bridge piles and surfacesubsidence, finally it compared between simulation settlement data and field data toverify the accuracy of the simulation, and analysed the reasons there may bedifferences between them.（3）Suggestions in this project, it is necessary for soil grouting in the process ofconstruction to ensure the safety of the upper structure of the bridge and guidesubsequent construction.