Study On Pit Deformation By FLAC3D During Excavation And Construction Of Subway Station

With the rapid development of modern cities, large-scale underground space development is an inevitable trend. Subway station during the excavation of deep foundation pit has become a research focus in modern construction of urban underground space.On the background of deep foundation pit construction in LinHailu Station of Metro Line 5 in Shenzhen, the subway station deep excavation and the supporting theory are stated. The earth pressure of deep foundation pit supporting, the internal forces of retaining structure, the supporting deformation mechanism, the mutual deformation mechanism of support together with the soil mass as well as the influential factors of the internal force and deformation in retaining structure are analyzed. The field tests of the supporting structure system deformation, the measuring point distribution and the monitoring frequency are also entirely described. Using the FLAC3D, the model is established to simulate the excavation construction. The internal forces changes and the surface settlement of the retaining structure of deep foundation pit in subway station are studied.According to the field monitoring data of the surface settlement, the horizontal displacement of top wall, the lateral brace axial force and the horizontal displacement in deep foundation pit in subway station, the curves are drawn and the dynamic effect are obtained. The FLAC3D can help us better analyze the laws of deep excavation underground. Therefore, during the process of deep excavation of the subway station, the force and deformation are very important and significant. The research results can provide the references for the later project of deep foundation pit in subway station.