Application Study On The Double-row Piles Of Deep Foundation Pit In Xu Zhou

Double-row piles structure has a much higher lateral stiffness and the convenience of localoperation.However, there is little mature design method at Present. Based on the previous researchresults and the foundation excavation engineering of Yun Long mansion in Xu Zhou, the paperconducted the systematic research on triangle-shape double-row piles structure according to theanalysis of the measurement result and three dimensional numerical simulation. The main work andconclusions are as follows:(1) It is summarized that the design method and the pile-soil interaction theory of double-rowpiles. Then the earth pressure is anaslyzed in cases of different vertical and horizontal spacing byabaqus3D finite element program.(2) Based on the3D model by abaqus, the stresses of the soldier pile and the deformation areanalyzed in different influencing factor which include the vertical and horizontal spacing,embedment of the pile, stiffness of the pile, c and φ of the soil parameters; and the soil arch betweenpiles are simulated and researehed in different vertical and horizontal spacing. Then suggestionsof optimization are put forward. Besides, the stresses of the soldier pile and the deformation areanalyzed for the double-row piles structure containing braces/anchor. Load and deformation ofthese two structures are more reasonable.(3) According to the measurement results, the horizontal displacement of the retaining pilebody and the top beam, the settlement of the road and the building are analyzed. The analysis resultsdemonstrate the feasibility of the double-row piles structure.(4) The actual project is simulated by abaqus. Compared with the measurement results, thesimulated results follow similar trends and are the same order of magnitude. It shows that thesimulation is feasible. So a new design plan with double-row piles instead of reinforced concreteinternal support is put forward and is simulated. The simulated results shows that the displacementof the new plan can reach the requirements of the foundation excavation engineering in spite of alittle larger than before. From the aspects of construction, the construction period and the costs,double-row piles structure scheme is more beneficial.