Monitoring And Numerical Simulation Analysis Of Deep Foundation Pit In Subway Station

With the proliferation of high-rise building and subway construction, deep Foundation pit engineering gradually increased, but a lot of major accidents has happened and leaded to casualties and the destruction of the surrounding environment. Therefore, study on deformation of deep Foundation pit excavation process that can reduce and avoid a similar accident occurred. This article use a metro station deep pit engineering for research object, and utilize application theory analysis, site monitoring and the numerical simulation analysis phase combination of method to research the distribution of deep pit around soil body pressure and the deformation law of support nursing. This article's main the conclusions of research are as listed below:1. Through analyzing and finishing the data of Metro station pit monitoring, to research soil pressure deformation law in loess deep pit , which including the relationship between soil pressure and time, it also contain the relation of soil pressure and displacement. The conclusion shows that soil pressure changes with the changes of wall displacement at an early stage, when after the supporting structure stability, growth of earth pressure gradually over time tend to be of earth pressure at last. The relation between Earth pressure and displacement is nonlinear.2. Combination of Foundation pit deformation theory and field monitoring data of, to research dewatering of Foundation pit, variation of wall displacement and supporting Axis forces in the deep Foundation pit excavation`s process, From the analysis results: cast in site diaphragm wall played a important role to Block in Foundation pit water level rise, and be with support contain the stability of Foundation pit well too.3. Simulated the four process in excavation of deep Foundation pit by finite element software PLAXIS, mainly research on displacement and deformation of the diaphragm wall. For large buried deep into the surface of the diaphragm wall, up from the end of the wall's horizontal displacement assume exponential growth trend. By comparing the results with actual monitoring, both changes are basically the same.4. Use Li Zhen software for design of deep Foundation pit, to find the law how factor held up deep foundation becoming deformed, which include Foundation pit soil depth, horizontal distant of support, support materials, prestressing force of supporting imposed. From the results view, the depth into earth of the diaphragm wall, horizontal distant of support, support materials, prestressing force of supporting imposed exert some influence factors, if those factor's values in a specific range to effectively inhibit lateral displacement of Foundation pit soil, or those value beyond the scope of design, adversely affect will happened in the process of Foundation pit excavation. Lateral displacement of diaphragm wall and soil will increase as ground overload increases, so it's necessary to avoided putting a pile of abandoned soil or other devices in the construction process in around the Foundation.