Stability Analysis And Support Technology Research Of Side Wall Shared By Adjacent Deep Foundation Pit

With the continuous advancement of urbanization,the scale of construction continues to expand,resulting in increasingly tight urban land.In order to cope with the shortage of land resources,"upward" and "downward" development has become a trend,resulting in the production of a large number of super high-rise buildings or dense underground space structures,accompanied by large-scale foundation pit groups.Due to the limited construction area,there may be situations where adjacent deep foundation pits share sidewall construction.This paper takes the construction of the shared sidewall of adjacent deep foundation pits in a certain area of Xi’an as the background,adopts the methods of theoretical calculation,numerical simulation and on-site monitoring,etc.,the different excavation sequences of the adjacent deep foundation pits during the construction of the shared sidewall are used to support the foundation pit.T he main research work is as follows:(1)Summarize the deformation mechanism and failure modes of adjacent deep foundation pits and the factors affecting the deformation of deep foundation pits,and use the superposition method theory to derive the calculation formula for the active earth pressure of the finite soil between adjacent foundation pits.The coupling effect mechanism of adjacent deep foundation pits is sorted out,and the critical distance calculation formula is calculated.(2)Use the finite difference software FLAC3D to numerically simulate three different excavation conditions under the condition that adjacent deep foundation pits share sidewalls,and analyze the lateral displacement,internal force changes and changes of the foundation pit supporting structure under different excavation conditions.The change trend of the surface settlement of the middle soil body,and the change law is summarized.(3)By comparing the on-site deformation monitoring with the numerical simulation results under the same working conditions,the rationality of the numerical simulation is verified,and the rationality,effectiveness and feasibility of the supporting structure are further verified.