Theoretical Study And Numerical Simulation Of Supporting Structure With Double Row Pile

With the economic development of China, high-rise buildings and city subway tunnel projects have been built more and more, urban spaces are getting smaller, utilization of underground space enhance greatly, those make foundation pit project become more deep and more large, on this condition, double-row pile retaining structure was invented. Double-row piles retaining structure is one of the retaining methods which has been widely used in recent years. Based on single-row retaining structure, it moves some front pile to behind, and then use rigid connection girders to connect two rows of piles on the top. In this way, double-row piles retaining structure is established.Compared with single-row retaining structure, double-row pile retaining structure has obvious advantages, its lateral rigidity is greater, its supporting depth is deeper, its construction period was short, its stability is better and its cost is cheaper, at the same time, it can be without supporting under construction. Double-row pile retaining structure has been widely used in slope reinforcement and slopes against sliding and foundation pit project. At present, the mechanism of action of double-row pile retaining structure is not clear, its design theory is not perfect, engineering experiences are still the main basis of design and construction.The thesis summarizes the following content:collect a large number of papers which are related on double-row pile retaining structure, compare and analysis some models and calculation theories, and further classify and improve double-row pile theory. Based on the basic idea of elastic foundation beam method, correlation model has been put forward to, and then establish the model of a Taiyuan’s deep foundation pit project by using finite difference method analysis software Flac3D4.0and analyses the moment and displacement of soil and pile body. Keeping the initial engineering condition, respectively, to change row spacing, pile spacing, pile length, the beam size, friction angle, cohesion and foundation depth, and then record and arrange the data, use EXCEL software to draw the moment and displacement diagram along the pile body, summarize the variety rule of pile body’s moment and displacement; Considering the requirements of safe, economical and reasonable technical, a reasonable range of engineering design is given, and ultimately achieve the purpose of optimization of the support structure design.