饱和黏弹性地基土中管桩纵向振动研究

用解析方法在频率域内研究考虑质量耦合效应的饱和黏弹性地基土中管桩的纵向振动特性。基于Biot理论，采用薄层法，推导得到饱和黏弹性地基土的位移、应力等的表达式。将管桩等效为一维弹性杆件处理。根据界面连续性条件，给出饱和黏弹性地基土中管桩的纵向振动一般分析方法和桩顶动力复刚度的表达式。在该基础上，对比分析饱和地基土中实心桩和管桩纵向振动特性。通过算例分析，考察桩周土和桩芯土的力学参数对桩顶刚度因子和等效阻尼的影响。研究表明，饱和黏弹性地基土中实心桩和管桩的纵向振动有明显的差异。

Study of vertical vibration of pipe pile in saturated viscoelastic soil

Using the analytical method, vertical vibration characteristics of pipe pile in saturated viscoelastic soil considering mass-coupling effects are investigated in the frequency domain. Based on Biot’s dynamic theory, the expressions for displacement and stress of the saturated viscoelastic soil are obtained by using Novak’s layer method. The pipe pile is treated as the Euler-Bernoulli rod. By utilizing the continuity conditions between the soil and pipe pile, a general analysis method for the vertical vibration of the pipe pile in the saturated viscoelastic soil is presented; and the expression of the complex dynamic stiffness at the pile top is obtained. On the basis, the comparative analysis between the vertical vibration characteristics of solid pile and one of pipe pile in saturated soil is made. By using the numerical example, the influences of mechanical parameters of soil around the pile and inner soil on the dynamic stiffness factor and equivalent damping at the pile top are investigated. It is shown that the vertical vibration characteristics of solid pile and pipe pile have significant difference.