Study On The Influence Of Deep Foundation Excavation On Adjacent Buildings In Subway Station

With the development of the urban underground space and the rail transit construction,the surrounding environment condition of subway station foundation pit presents a trend of complexity obviously,so that it is need to be considered carefully that how the foundation pit construction impacts on the surrounding buildings.Although there are a lot of analysis research on the interaction between foundation pit engineering and the surrounding environment,the influence of the retaining structure deformation and the surrounding ground surface subsidence on the adjacent buildings has yet to be further discussed.On the background of the deep foundation pit engineering of Dengzhou station on Foshan metro No.2 line and based on the qualitative analysis of the results of previous studies,this paper induced and analyzed the data obtained from the field monitoring,established the three-dimensional finite element model of the excavation process of the metro foundation pit,and analyzed the result of the retaining structure deformation,the supporting axial force and the surrounding surface settlement on the adjacent buildings and its change rule.Main contributions are as follows.Firstly,summarized the research situation domestically and abroad,induced the theoretical research achievement the predecessors have made from the aspect of influence on foundation pit body and the peripheral environment owing to the foundation pit construction.Secondly,processed and analyzed the data of the retaining structure deformation,the ground surface settlement,the supporting axial force and the building foundation settlement obtained from the field monitoring.Researched the regularity of retaining structure horizontal deformation,the ground surface subsidence and the supporting axial force change.The relevance between the retaining structure deformation and the surrounding building settlement and the relevance between the ground surface subsidence and the surrounding building settlement were also analyzed.Thirdly,finite element analysis software ABAQUS was used to simulate the excavation of deep foundation pit numerically.With consideration of the deep foundation pit’s multi-staged excavation with the supporting arranged layer by layer and the interaction between retaining structure and soil,the Mohr-Coulomb model was selected as the constitutive model of soil to quantitatively calculate the dynamic effect of the deformation of the retaining structure,surface settlement and supporting axial force on the settlement of the surrounding buildings under the conditions during the process of the excavation step by step.Fourthly,the numerical simulation results were compared with the field measured data.And the parameter sensitivity analysis of building settlement was carried out to obtain a few conclusions which are of practical significance to the design and construction of the deep foundation pit engineering.