Analysis And Research On The Optimization And Selection Of Supporting Structure For Deep Foundation Pit Of Building

With continuously increasing of our population, shortage of land resources, so that we need to make full use of urban ground space and underground space, thus leading to the excavation and supporting of many foundation pit projects, which provide necessary and security environment for the construction of substructure work. Construction of excavation of deep foundation pit, to supporting of foundation pit wall, not only need to consider the complexity of site hydrology, engineering geological conditions, but also fully consider the difficulty and feasibility of construction in the confined space environmental conditions. Therefore, the suitability, security and economy of supporting design of foundation pit projects is the main basis for selecting design and construction method.Foundation pit supporting optimization design is that the design has significant relevance on engineering features, hydrology, engineering geological conditions and environmental conditions, highlighting the rational, scientific design achievements and better reflect the suitability safety and economy of the design achievements. What's more, optimizing of foundation pit supporting type and supporting design calculations, is the key to solve the difficulties and focus.This paper bases on Huiyan foundation pit engineering from Zhangyan village Hufang Town Qingshanhu District Nanchang City, and combines with deep foundation pit engineering theory and practice, describes several widely used types of foundation pit supporting, and their advantages and disadvantages as well as scope of application; And analyzes some of the factors affecting the design of deep foundation pit supporting. In deep foundation pit design theory, taking safe, reliable, cost-saving projects, short construction period, low impact on the surrounding environment, simple construction as the aim of optimization, and using multi-program comparison analysis to construct a relatively complete structure of the program of deep foundation pit preferred system. Combined with the environmental conditions, engineering geological conditions, depth of excavation and so many factors, we choose a safe and reliable support program. Here considering the factors of foundation pit is deep and large etc. in order to ensure security, we take pile anchor supporting and pile brace supporting these two supporting programs. Finally, in order to a more comprehensive analysis of supporting effect, we use Lizheng deep foundation pit F-SPW7.0 to simulate and calculate above two programs, analyze the stress and displacement of each components, and compare with the r esults of the previous calculation, analyze the difference between them in detail. After the optimization of the supporting program, take a detailed design, and finally choose the best supporting program. Compared with the original supporting programs, a new supporting program reduce the project cost under ensuring the basic stability of the foundation pit, which has certain guiding significance to the similar foundation pit supporting design in the future.