Design Methods Study On Anchor Supporting Pile Of Deep Foundation Pit In Taiyuan

With the increasing of urban constructions and the technology development, deep foundation pit engineering have been got extensive application. It becomes critically important that how to acquire good balance between structure safety and economic benefit. It need us to do further research about design theories and methods of deep foundation pit.It is well known that foundation pit engineering is a systems engineering which involving in lots of field such as structure mechanics, soil mechanics, ground base and foundation, ground treatment, experiment test and construction. Meanwhile, the foundation pit engineering is a strong regional engineering which varied from district. Aimed at the example, deep foundation pit in Tai Yuan Chuangye building, the paper did comprehensive calculation and analysis of multi-fulcrum anchor supporting pile structure. By comparing with practice determining data, performed the evaluation to design and analysis methods.This paper did some work as below:1. from the common design theory of foundation pit aspect, expound the basis design principle and the latest research in relevant field at present.2. discussed several major problems of anchor supporting pile structure design, such as earth pressure selected, mechanism of structure, parameter defined and model of FEM imitating foundation established.3. evaluated the common design methods of anchor supporting pile. Apply2d-σ FEM software which assembled by Japan Soft-Brain co. to imitate and analyze the example.4. divided the construction procedure into several operating modes, analyzed the different internal force and displacement under different modes.5. based on the practice determining data, raised the suggestive conclusion that using "m" method to design supporting pile is conservation at internal force result while satisfaction at displacement result. It well meet the practice by using "c" methods under whole triangle earth pressure distribution to design at internal force result.6. indicated from analyzing by plane FEM, soil's constitutive model and parameter influence greatly the supporting pile structure. Though the result with FEM totally coincide the practice determining data from the trend, it still has different from values. In fact, using FEM alone to do foundation pit design is not reliable. It must be supported by sufficient laboratory report and in-situ test data. With the development of technology, it is believed that the day will come soon to design with FEM.7. because the design theory of supporting pile is not mature, it is essential to emphasis in-situ testing and monitoring. Using information to construct is not only assure smooth excavation construction, but also gain great benefit.