关键词: 管桩, 轴对称模型, 竖向振动, 复刚度

Abstract: The mechanical properties of pipe pile and solid pile are significantly different due to the plugging effect and the existence of pile core soil during pile driving process. Hence it is necessary to study the influence of the difference between the soil around the pile and pile core soil on the vibration of pipe pile in soil. By using the axisymmetric model and pile-soil contact surface continuity conditions, the solutions to vertical vibration of pipe pile in soil are obtained with the soil around the pile, pile core soil and pipe pile as a whole. For comparison, the Euler model-based solutions are also derived. Comparisons are performed among the results obtained by various methods. The results indicate that the complex stiffness at pile head obtained by using axisymmetric model is smaller than the complex stiffness obtained with Euler model, and there exists a certain gap between the results by the two models. The dynamic stiffness and dynamic damping becomes smaller when the shear modulus of soil around pile is larger than that of the pile core soil. The complex stiffness at pile head is smaller when the wall thickness is smaller. Hence the wall of pipe pile should not be too thin. In the design of pipe pile, it is necessary to consider the influence of soil properties on the vibration of pipe pile in soil, and properly select the interior radius, outer radius and length of the pipe pile.

Key words: pipe pile, axisymmetric model, vertical vibration, complex stiffness