| When a large number of high-rise buildings and super high-rise buildings emerge in China,the burial depth of foundation is getting deeper and the scale of underground space become larger and larger.The number of large projects,such as open tunnels,subway stations and urban square,are increasing.Therefore,to develop deep foundation pit support technology is an effective method to optimize the foundation pit retaining structure system rationally.On the basis of collecting and collating relevant literature and investigation data,this paper carries out the research on large deep foundation pit support system and special construction,taking the support engineering of open-excavation foundation pit in Luoyang railway station and subway station as the research background.Firstly,this paper introduces the regional geological background and engineering geological survey of Luoyang area,and the geotechnical engineering characteristics of the subway station are investigated and analyzed.Then,the deformation effect of foundation pit and support system after excavation is studied by physical model test,emphatically the change characteristics of pile displacement caused by lateral displacement of foundation pit.The stability of foundation pit and support structure after excavation is revealed,which provides basis for foundation pit design.Secondly,FLAC3D finite difference software is used to establish the numerical model of the foundation pit and supporting structure.Through numerical calculation,the change rules of the stress and displacement of foundation pit are analyzed.Meanwhile,the analysis of the stress and displacement of the support structure is compared with the model test results,to optimize and supplement the model test.Finally,the deep foundation pit project of Luoyang metro railway station is studied of the special construction design,focusing on the design of foundation pit excavation,drainage,support,and the safety and monitoring of foundation pit construction.The research results of this paper have important guiding significance for the design of deep foundation pit in Luoyang subway station,and have reference value for the design of excavation and support on similar foundation pit. |
