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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。
The occlusion effect and the presence of pile core and soil in the process of pipe pile sinking make the difference between the mechanical properties of the pile and the solid pile. Therefore, it is necessary to investigate the difference of the mechanical properties between the pile soil and pile core, influences. Taking the surrounding soil as a whole, the pile core soil and the pipe pile as a whole, the vertical vibration solutions of the pipe pile are obtained by using the axial symmetry model and the continuity condition of the pile-soil contact surface. For the sake of comparison, Solution to the oscillating Euler model. By numerical examples, the axial stiffness of the pipe pile and the complex stiffness of the pile top obtained by the Euler model are compared and analyzed. The results show that the physical parameters of pile surrounding soil, Impact. The results show that the complex stiffness of pile top obtained by axisymmetric model is smaller than that of Euler model, and there is a certain difference between the two models. When the shear modulus of soil around pile is larger than the shear modulus of pile, The dynamic stiffness and the dynamic damping of the pile foundation are smaller; the complex stiffness of the pile top decreases with the decrease of the pipe wall thickness, so the wall of the pipe pile should not be too thin. During the design of pipe pile, the influence of soil properties on the vibration characteristics of pile foundation needs to be considered, and the inner and outer radius and pile length of pipe pile are reasonably selected.