非饱和土中单桩竖向振动简化分析

刘圆圆; 孙箭林

doi:10.20265/j.cnki.issn.1007-2993.2024-0452

非饱和土中单桩竖向振动简化分析

doi: 10.20265/j.cnki.issn.1007-2993.2024-0452

刘圆圆^1,,
孙箭林²

1.
江西建设职业技术学院，江西南昌　330052
2.
江西师范大学，江西南昌　330025

基金项目: 江西省教育厅科技项目（GJJ2207305）

详细信息

作者简介:
刘圆圆，女，1988年生，硕士，讲师，研究方向为岩土工程桩基振动。E-mail：lyyhunan@gmail.com

中图分类号: TU473
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- 被引次数: 0
出版历程
- 收稿日期: 2024-10-05
- 修回日期: 2025-02-17
- 录用日期: 2025-06-26
- 刊出日期: 2026-08-08

A simplified analysis model for vertical vibration of a single pile in unsaturated soil

LIU Yuanyuan^1
,,
SUN Jianlin²

1.
Jiangxi College of Construction, Nanchang 330052, Jiangxi, China
2.
Jiangxi Normal University, Nanchang 330025, Jiangxi, China

摘要

摘要: 本文研究了均质非饱和土中单桩在竖向稳态荷载作用下的动力特性，将桩周土看作固液气三相介质，建立了三维轴对称简谐荷载作用下非饱和土中单桩的竖向振动简化模型，借助Novak薄层理论，化简了三维动力控制方程，求解了非饱和土振动阻抗因子，并结合桩土边界条件对桩的振动平衡方程进行求解，获得了桩顶复刚度和桩身内力的表达式。通过对比计算验证了本文简化模型及其解答的正确性，分析了相关参数对桩基竖向动力特性的影响。参数分析表明：桩顶动刚度因子振幅随频率增大而增大，而等效阻尼的振幅基本保持不变；饱和度对桩的动刚度因子和等效阻尼振幅有一定影响，随饱和度的增大而减小；桩土模量比对桩顶复刚度的影响显著，在保持桩的模量不变的情况下，随着桩土模量比的增大，桩顶复刚度振幅及峰值对应的频率间隔显著增大；渗透率对桩顶复刚度的影响相对较小；不同频率下，桩身的内力和位移变化显著，频率越大，桩身位移和内力振幅峰值越大。
- 非饱和土 /
- 单桩 /
- 竖向振动 /
- 薄层法
Abstract: The dynamic response of a single pile in homogeneous unsaturated soil subjected to vertical harmonic load is investigated. The soil around the pile is regarded as a solid-liquid-gas three-phase medium, and a simplified vertical vibration model of a single pile in unsaturated soil under harmonic load is established. The three-dimensional dynamic governing equation of unsaturated soil was simplified by using Novak's thin-layer theory. After solving the vibration impedance factor of unsaturated soil, combined with the boundary conditions of pile and soil, the vibration balance equation of the pile was solved, and the expressions of the complex stiffness at the pile top and the internal force of the pile were obtained. The correctness of the model and solution is verified by comparison calculation, and the influence of relevant parameters on the dynamic characteristics of pile foundation are discussed. The results show that the dynamic stiffness factor increases with the increase of frequency, while the damping factor remains unchanged. The saturation degree has little effect on the stiffness factor and the damping factor, which decreases as the saturation degree increases. The pile-to-soil modulus ratio has a significant effect on dynamic behaviors of pile in unsaturated soil. With the increase of the pile-to-soil modulus ratio, the amplitude of the complex stiffness of pile top and the frequency interval corresponding to the peak value gradually increase. Permeability has little effect on the complex stiffness of pile top. Under different excitation frequencies, the internal force and displacement of the pile shaft vary significantly, and the greater the frequency, the greater the peak value of the displacement and internal force amplitude of the pile shaft.
- unsaturated soil /
- single pile /
- vertical vibration /
- thin layer method

HTML全文

图 1 桩土计算模型

Figure 1. Simplified mechanical model of pile–soil interaction

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图 2 本文解与文献[12]解析解对比

Figure 2. Compared with the solution of reference [12]

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图 3 本文退化解与文献[5]解对比

Figure 3. Compared with the solution of reference [5]

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图 4 饱和度对桩顶复刚度影响

Figure 4. Effects of saturation on stiffness factor and equivalent viscous damping

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图 5 渗透系数对桩顶复刚度的影响

Figure 5. Effects of permeability coefficient on stiffness factor and equivalent viscous damping

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图 6 桩土模量比对桩顶复刚度的影响

Figure 6. Effects of the ratio of modulus on stiffness factor and equivalent viscous damping

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图 7 桩身位移随频率的变化

Figure 7. Vertical displacement distribution of the pile under different frequency

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图 8 桩身内力随频率的变化

Figure 8. Vertical internal force distribution of the pile under different damping

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