Study On The Construction Mechanics And Deformation Of Surrounding Building In Foundation Pit Of Large-span Subway Station

At present,large cities are speeding up the construction of subway,metro cities gradually becomes the most fast and efficient transportation in cities.The current subway station scale is becoming more and more big,and the station is usually located in the bustling heart of the city,skyscrapers,underground pipeline complex,heavy traffic flow which increase the risk of the construction of Foundation Pit Engineering.So we should not only consider its own security,but also research its impact on the surrounding buildings during excavation,to ensure their safety of own stability and the surrounding buildings during excavation.How to control the deformation of the foundation pit,to ensure safety has been one of the topics explored in geotechnical engineering,and it also made a series of research results.The effect of Deep Foundation Pit Excavation on the surrounding buildings is mainly due to stress relief of soil cause deformation of supporting structure and surrounding rock and soil,leading to sedimentation or tilt of base and the upper structure.After reading a lot of relevant literature,concluded on the basis of previous research.In this paper we take the subway station of Xiamen City Rail Transit Line 1 as background,By numerical simulation and field monitoring measurement to study the impact on the surrounding buildings during excavation,the main contents are as follows:① By summarizing the previous studies results,we use knowledge of soil mechanics and rock mechanics to research mechanism of rock and soil deformation and deformation law of the building in the excavation process,while giving the building settlement and tilt control targets:foundation settlement of building is 10mm,the rate of tilt is 0.002.② Establishing a three-dimensional numerical model to simulate the excavation process,and compare FEM simulation results in vertical displacement of the building with field monitoring results to prove this simulation process and the results are reliable.③ Establishing a two-dimensional model of excavation,research the relationship between the security status of the building and the excavation depth H,the distance between the building and foundation pit S.④ In view of the adjacent building large-span excavation of metro station,in order to guarantee the safety of foundation pit and surrounding buildings,the auxiliary measures such as construction control measures and the construction monitoring are put forward.