Abstract: Considering?the?three-dimensional?wave?effect?of?the?soil?pile,?vertical?vibration?characteristics?of?the?variable?impedance?pile?is?analyzed?when?the?layered?viscous?damping?materials?in?the?soil?pile?is?affected?by?any?axial?exciting?timevarying?force.?And?then?the?analytical?solutions?for?frequency?domain?response,?complex?stiffness?and?velocity?admittance?are?obtained.?The?influence?of?modulus?change?of?soil?at?the?bottom?of?the?pile?and?impedance?change?in?pile?on?the?vibration?characteristics?of?vertical?pile?is?analyzed.

Key words: 3D wave effect , viscous materials , frequency domain response , complex stiffness , velocity admittance

摘要： 考虑桩周土体的三维波动效应,分析成层黏性材料阻尼土中桩顶受任意轴向激振力作用时变阻抗桩的纵向 振动特性,求得桩顶频域响应解析解、复刚度和速度导纳,分析了底部土层模量变化和桩身阻抗变化对桩纵向振动 特性的影响。

关键词: 三维波动效应, 黏性材料, 频域响应, 复刚度, 速度导纳