The Research On Mechanical Properties Of Deep Foundation Pit Construction In Subway Station Adjacent To Existing Station

With the rapid expansion of urban rail transit network,more transfer stations are under construction,For the condition of adjacent station,the deep foundation pit of new subway station will be affected in the construction process.At the same time,the influence of the construction of the post-construction project on the pre-construction project should be evaluated reasonably.Based on the deep foundation pit project of Laoguancun station of Wuhan rail transit line 16,according to the engineering characteristics of the construction conditions and the site surrounding environment,on the basis of analyzing and summarizing the previous research results,the method of combining field monitoring and finite element numerical simulation is adopted to analyze the law of stress and deformation of deep foundation pit during excavation and support construction,it shows that combined support of underground diaphragm wall and internal support is applicable to this engineering project,which Under the condition of open cut method.It ensures the effective construction of the main structure of the station.At the same time,the influence of foundation pit excavation on the existing station is within the controllable scope of project management.The main research work and conclusions are as follows:(1)This article has described the main features of stress and deformation mechanism of deep foundation pit of subway station in the process of excavation and support construction,it shows that the physical and mechanical properties of soil in the excavation depth of the foundation pit set by the support system of the retaining structure.(2)It has introduced the general situation of the subway station and analyzed the monitoring scheme of deep foundation pit design and construction.Based on the analysis and arrangement of the field measured data,the stress and deformation of the retaining structure and the settlement law of the ground around the deep foundation pit in subway station during the excavation and support construction are studied in detail.The results show that the existing deep foundation pit retaining structure system is safe and reliable,which also proves that the design,construction and monitoring scheme of this project is reasonable and feasible.(3)The three-dimensional finite element model of this engineering was established to analyze the horizontal displacement of underground diaphragm wall,supporting axial force,the ground surface settlement and the mechanical characteristics to main structure of pre-existing subway station,which can be compared with measured data.Finally,some Suggestions for monitoring and construction of deep foundation pit in subway station have been put forward.