中文摘要：

基于Rayleigh-Love杆模型研究考虑施工扰动效应时大直径扩底桩的纵向振动阻抗。首先,分别采用虚土桩模型和径向圈层间的剪切复刚度传递法考虑施工扰动造成的桩端以下土体的竖向非均质性和桩周土的径向非均质性;然后,求解桩–土界面的剪切复刚度,将其代入到桩的纵向振动控制方程中,通过Laplace变换和阻抗函数递推的方法,得到大直径扩底桩纵向振动频域响应解析解,在此基础上,通过与已有研究成果的对比,证明本文解的合理性;最后,通过参数分析的方法,在桩基动力设计中比较关心的低频范围内研究了桩的扩底参数以及施工扰动效应对大直径扩底桩纵向振动阻抗的影响,结果表明：（1）扩底半径对桩的动力特性的影响远大于扩底段长度的影响;（2）施工扰动效应对大直径扩底桩的动力特性影响显著,且桩周土扰动的影响要强于桩端以下土体扰动的影响。

英文摘要：

Based on the Rayleigh-Love rod model, the longitudinal dynamic impedance of a large-diameter belled pile is theoretically investigated considering the construction disturbance effect. First, the virtual soil pile model and the shear complex stiffness transfer method are adopted to simulate the vertical inhomogeneity of the pile end soil and the radial inhomogeneity of the surrounding soil caused by the construction disturbance effect, respectively. Then, the shear complex stiffness at the pile-soil interface is solved and is substituted into the goveming equation of the pile. Meanwhile, the analytical solution for the dynamic response at the pile head is obtained in the frequency domain by virtue of impedance function transfer method and Laplace transform method. On this basis, comparisons with published solutions are carried out to verify the reliability of the present solution. Finally, by means of parametric analysis method, the influence of pile parameters and the construction disturbance effect on the complex impedance at the pile head is investigated within the low frequency range concerned in the design of dynamic foundation. The results show that. （1） the influence of the radius of the enlarged base on the complex impedance at the pile head is much greater than that of the length of the enlarged base. （2） The dynamic characteristic of the large-diameter belled pile is greatly affected by the construction disturbance effect, besides, the influence of the disturbance of the pile surrounding soil is greater than that of the disturbance of the pile end soil.