大直径群桩基础承载特性现场试验及数值模拟.

Large-diameter pile group foundations have the characteristics of high bearing capacity, and have broad application prospects in large-scale engineering foundations in soft soil areas. Based on the field test data of vertical bearing capacity of a bridge group pile foundation, the ABAQUS numerical calculation platform is used to calculate and fit the soil parameters. Based on the soil parameters obtained from the fitting, the bearing characteristics of the piles under the horizontal load are calculated and analyzed, and the bearing characteristics of the group pile foundation under vertical and horizontal loads are also studied. The results show that when the maximum vertical load acts on the cap-pile group foundation, the maximum displacement of the cap is 84.83 mm, and according to the displacement control principle, the upper limit of the pile group effect is 83%, and the lower limit is about 62.8%. Under the vertical load, there are differences in the settlement value of each pile in the pile group, the center piles are the largest, followed by the side piles, the corner piles have the smallest settlement. With the load gradually increased, the displacement differences of the corner piles, the side piles and the center piles show a trend of first increasing and then decreasing. When the maximum vertical load is applied to the group pile foundation, the horizontal influence range of foundation horizontal displacement is about 1.5 times of the side length of cap, and the maximum influence depth is about 1.5 times of the side length of cap. The soil between piles shows tension shear stress in the range of 0.5 times of side length of cap below the ground surface. This paper analyzes the bearing characteristics of pile groups under horizontal and vertical loads and its conclusions can be used for reference for relevant engineering design. [ABSTRACT FROM AUTHOR]