The Influence Of Deep Foundation Excavation On Adjacent Metro Tunnel

Deep foundation pit excavation and dewatering problems cause settlement of surrounding soils is an important research content of foundation pit engineering.In recent years,due to the acceleration of urbanization in recent years,urban land has become increasingly tense,and reasonable utilization of urban underground space has become the focus of attention.More and more deep foundation pit engineering is bound to cause the surrounding environment problems,including the deformation and strength safety of deep foundation pit engineering and the influence of the surrounding environment.A foundation pit under construction in the adjacent subway tunnel of Changsha Metro Line 5 was studied based on the Biot's Consolidation Theory in the thesis.The main work and results are as follows:Reference related literature at home and abroad,summarized the research status about the excavation surrounding ground deformation and seepage consolidation theory,analyzed the main factors influencing the tunnel deformation and internal force in the thesis.A three-dimensional numerical analysis model was established by using Midas GTS NX to reconstruct the modified Mohr-Coulomb constitutive relationship.The sensitivity of the precipitation velocity influencing on the adjacent subway tunnel and the construction stages on different conditions were analyzed at first.The unidirectional coupling analysis of the stress seepage and the coupling analysis of the complete stress seepage were carried out later.The actual monitoring results were comparatively analyzed in the end.The results showed that the accelerating precipitation velocity of the foundation pit led to the non-linear growth of the structure inner force under certain conditions.The sensitivity of the precipitation velocity influencing on the adjacent subway tunnel and the construction stages on different conditions were analyzed at first.The unidirectional coupling analysis of the stress seepage and the coupling analysis of the complete stress seepage were carried out later.The actual monitoring results were comparatively analyzed in the end.It tended to be stable up to a certain degree later on.The results based on the coupling analysis of the complete stress seepage of are more in line with the actual monitoring results than that of the unidirectional coupling analysis of the stress seepage.The maximum deformation controlresults of the subway tunnel met requirements of the relevant specifications.The analysis results can provide a reference for similar projects.