Study On The Influence Of Deep Foundation Pit Excavation In Metro Station Adjacent To High-rise Buildings

Because of the complicated geography condition, the city subway deep foundation pit is usually surrounded with dense buildings. So the foundation pit excavation and supporting is very difficult, because that they not only affect the security and stability of foundation pit, will also affect adjacent buildings.This paper takes the deep foundation pit of Hongfu road station, which is the transfer station of line R1 and R2 of Dongguan city rail transit, as an background. Combining with the construction site’s engineering geological and hydrogeological conditions, a study concerning the impact of foundation pit’s excavation upon retaining structure and surrounding soils, and buildings was made. The research content is as follows:1. This paper has set up a 3-D model of the retaining structure and foundation pit and construction which is analyzed by using the finite difference software FLAC3D. The numerical simulation is carried to analyze the deformation of foundation pit and the stress and deformation of retaining structure and the displacement of building during excavation. The result of numerical simulation demonstrates the validity of the calculation model.2. Combining the theory of deformation caused by foundation pit’s excavation, this paper has analysed the reason of retaining structure’s deformation and Surrounding ground settlement and building’s settlement, incline and horizontal displacement caused by deep foundation pit’s excavation where adjacent to buildings, and summarized the effect laws of foundation pit’s excavation.3. This paper has also revealed more laws which have practical significance for design and construction of foundation pit engineering that adjacent to high-rise building by carrying a further numerical simulation under different conditions, include (a)the different distance between deep foundation pit and the adjacent structures;(b) different parameters of supports;(c)different excavation methods are used.The obtained conclusion can provide some reference for design and construction of similar deep foundation pit engineering in the future.