Study On The Mechanical Behaviors Of Retaining Structure Of Multi-pivots Deep Foundation Pit

With the rapidly development of city construction, there is an increasing lack of land resources in the cities. More and more high-rise buildings and super high-rise buildings are being built. In order to optimize the space, the city underground space is more development and utilization. So, many deep foundation pits are appeared. For the sake of making the deep foundation safe and stable, it is necessary to make a stable retaining structure and protecting. At present, the main work of the foundation pit is to control the force and deformation to get it in construction safety.This paper bases on one foundation project case of Changsha subway station, and uses analytical method and numerical simulation method to analyze the force of supporting structure when excavating and supporting. Finally gets the changing rule on the internal force of the retaining structures. Arranging the actual monitoring date as the basis for comparison, and analyzing the effects of the construction method, strut stiffness, perforce on the internal force of the retaining structures. The main work and research contents are as following:(1) Though consulting and studying the massive literatures, this paper has discussed and summarized the status of deep foundation pit, and the design of supporting structure. The paper also summarizes the method of calculation such as internal force analysis, classic soil mechanics theory and finite element method.(2) The paper uses analytical method and classic soil mechanics to calculate the force of supporting structure, and study the regular of it.(3) Using 3-dimensional finite elements software, the paper creates a model, and simulates the process of excavating and supporting. It calculates the force and the distribution of each step.(4) Through arranging the actual monitoring date, the paper gets the internal force and displacement of the supporting structure in actual and compared with the calculation results.(5) Using 3-dimensional finite elements software, through changing the construction method and the parameters of supporting structure, the paper summarizes the influence of the internal force of supporting structure with these different parameters.