中文摘要：

在管桩沉桩过程中产生的闭塞效应以及桩芯土的存在,使得管桩的力学特性与实心桩存在着差异,因此需要考察桩周土和桩芯土力学性质的差异对管桩振动的影响。将桩周土、桩芯土和管桩视为一个整体,利用轴对称模型和桩-土接触面的连续性条件得到了管桩的竖向振动解,为了比较,也给出了管桩竖向振动的欧拉模型解。借助数值算例,对比分析了管桩竖向振动采用轴对称模型和欧拉模型得到的桩顶复刚度,并分析了桩周土、桩芯土和桩体本身物理参数对管桩竖向振动的影响。研究结果表明,轴对称模型得到的桩顶复刚度较欧拉模型的结果小,两种模型得到的结果存在一定的差异;桩周土剪切模量比桩芯土剪切模量大时,桩基动刚度和动阻尼则较小;桩顶的复刚度随管桩壁厚的减小而减小,因此,管桩管壁不宜过薄。在进行管桩设计时,需要考虑土体性质对桩基振动特性的影响,合理选择管桩内、外半径和桩长。

英文摘要：

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.