Study Of The Technology Of Non-prop Retaining Structure In Large Area Of Deep Foundation Pit With Soft Soil

In the process of urbanization, the development and utilization of undergroundspace plays an important role. A large number of foundation pit engineering in ourcountry, especially in large area of deep foundation pit with soft soil, retainingsystems with supporting structure are widely used. Most of the support systems arenot recycled or high energy consumption, which makes the construction cost and thecycle increased significantly.In view of the above-mentioned problems, this paper puts forward the systemresearch on the technology of non-prop retaining structure. That is, using a variety ofnew type of supporting systems in large area of deep excavation foundation pit withsoft soil to guarantee the deformation and stability of foundation pit meet therequirements and do not use support so as to achieve the purpose of saving and green.To achieve this purpose, this paper puts forward two kinds of solutions.One of the solutions could be called "modified non-prop retaining structuretechnology", including double-row contiguous retaining piles with raking front-rowpiles, inclined single row contiguous retaining piles and staggered inclined single rowcontiguous retaining piles, etc. The benchmark models are established for mechanismresearch, focusing on the maximum displacement of pile, bending moment, shearforce, the pit precipitation index. Then the parameter analysis was did, the effect ofthe parameters was analyzed, including the dip angle of the piles, the length of piles(the change of the length of the front or behind piles), pile spacing(the equivalentflexural stiffness) and the length of link(the distance between the front and behindpiles).The other solution could be called "combinations of non-prop retaining structuretechnology ", multi-stage retaining structures are mainly used. At first, this paperstudies and presents a method to calculate the horizontal displacement of single stageretaining structure without support, which provides a theoretical basis and referencefor the engineering practice. Then the laws of displacement and stability of non-propand multi-stage retaining structure and parameters influence are studied and analyzed.These conclusions provide a theoretical basis for the subsequent research on the the technology of non-prop retaining structure in large area of deep foundation pit withsoft soil. In addition, this paper has also established a calculation method forcalculating the horizontal displacement of retaining structure.