Applications Study Of Double-row Piles Supporting To Deep Excavations

In recent years, with the increasing development of urban construction, the development and utilization of underground space is continuously increasing, along with the emergence of a large number of foundation pit engineering. The foundation pit engineering in urban construction has a significant site constraints and strict deformation control requirements. While as a new retaining structure, double-row pile gets a more lateral stiffness which can effectively restrict lateral deformation, making it ease to excavate and shorten the construction period, etc.. All of the above mentioned merits can adapt to the need of foundation pit engineering.Based on the research status of double-row pile retaining structure, this thesis mainly does the following research work:First, it analyses and summarizes the calculation model and calculation method of the existing double-row pile retaining structures, and makes a assessment to their reasonableness; Then, respectively considering the effect of different row space, pile length, and coupling beam stiffness on the internal forces and deformation of the retaining structure, this thesis uses finite element software for analysis and studies the influence rule of active area, passive areas and surrounding pile soil reinforcement on the supporting performance of double-row pile; Finally, according to the specific foundation pit engineering as "Green Square and Parking Area of Bamboo and Wooden Slips Mmuseum in Changsha", this thesis adopts the proportional coefficient method to calculate the earth pressure on the front pile and the back pile, uses plane frame model to calculate the internal force of the retaining structure, employs equivalent stiffness principle to calculate the equivalent stiffness of the retaining structure, and introduces lateral displacement calculation method of the cement retaining wall retaining structure to calculate the lateral displacement of the double-row pile retaining structure.This thesis uses finite element software ANSYS 10.0 for modeling analysis, and the results are compared with theoretical calculations. There is good agreement between the two results, proving the calculation method of double-piles of this thesis is feasible, which can provide some useful reference for the design of double-pile retaining structure.