基于轴对称连续介质模型的径向非均质土中大直径管桩纵向振动特性研究  

Research of longitudinal vibration characteristics of large-diameter pipe piles in radially heterogeneous soils based on axisymmetric continuum model

作　　者：崔春义[1] 梁志孟 许成顺[2] 孟坤[1] 辛宇[1] 裴华富 CUI Chunyi;LIANG Zhimeng;XU Chengshun;MENG Kun;XIN Yu;PEI Huafu(Department of Civil Engineering,Dalian Maritime University,Dalian,Liaoning 116026,China;Key Laboratory of Urban Security and Disaster Engineering,Beijing University of Technology,Beijing 100124,China;State Key Laboratory of Coastal and Offshore Engineering,Dalian University of Technology,Dalian,Liaoning 116024,China)

机构地区：[1]大连海事大学土木工程系,辽宁大连116026 [2]北京工业大学城市与工程安全减灾省部共建教育部重点实验室,北京100124 [3]大连理工大学海岸和近海工程国家重点实验室,辽宁大连116024

出　　处：《岩石力学与工程学报》2022年第5期1031-1044,共14页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金面上项目(52178315,51878109);“双一流”建设专项资金(BSCXXM022)。

摘　　要：基于Rayleigh-Love杆模型和三维连续介质模型,综合考虑土体竖向波动效应和桩身横向惯性效应,建立三维轴对称径向非均质黏性阻尼土–大直径管桩纵向振动相互作用分析模型;通过采用拉普拉斯变换和复刚度传递法,递推得到桩芯、桩侧土体与管桩内外壁接触界面处的关系表达式,并基于桩-土完全耦合条件推导出大直径管桩桩顶动力阻抗解析解;进一步利用傅里叶逆变换和卷积定理,求解出大直径管桩桩顶时域响应半解析解,将所得解析解退化并与已有解答进行对比分析,以验证其合理性。在此基础上,通过进一步参数化分析,探讨桩身泊松比、桩身波速、桩侧土施工扰动效应对大直径管桩动力响应特性的影响规律。结果表明:(1)随着桩身泊松比的增大,桩顶速度导纳曲线振幅和共振频率均减小,且反射波曲线出现明显的振荡现象。(2)桩顶速度导纳曲线和桩底反射信号的幅值随桩身波速的增大而增大。(3)考虑桩身横向惯性效应时,施工扰动效应对桩顶动力响应的影响更为显著。(4)通过将推导所得解退化并与已有相关解答解进行对比分析,验证了其合理性和精度,可为桩基纵向振动分析和设计提供参考。Based on the Rayleigh-Love rod model and three-dimensional continuum theory and considering the transverse inertia effect of piles and the vertical wave effect of soil,an interaction analysis model for the longitudinal vibration of a large-diameter pipe pile in three-dimensional axisymmetric radial inhomogeneous viscous damping soil is established.By utilizing Laplace transforms and complex stiffness transfer method,the interaction expression at the interface of pile and soil is also derived.Under the assumption of perfectly coupled condition between the pile and the soil,the semi-analytical solution for the dynamic response at the large-diameter pipe pile head is obtained in time domain by using Fourier inversion and convolution theorem.Then,the present analytical solution is reduced to verify its validity by comparison with the existing solutions.Finally,an extensive parametric analysis is conducted to investigate the effects of the Poisson’s ratio and the wave velocity of the pile as well as the construction disturbance of the soil on the dynamic response of the large-diameter pipe pile.The results show that:(1)With increasing the Poisson’s ratio of the pile shaft,both the amplitude and the resonance frequency of the velocity admittance curve at the pile head decrease and the reflected wave curve shows obvious oscillation phenomenon.(2)Both the velocity admittance curve at the pile head and the amplitude of reflected signals at the pile bottom increase with increasing the wave velocity of the pile shaft.(3)When the transverse inertia effect of the pile shaft is considered,the influence of the construction disturbance effect on the dynamic response at the pile head is more significant.(4)By degenerating the derived solution and comparing it with the existing solutions,the rationality and accuracy of the solution are verified.The research can provide a reference for the longitudinal vibration analysis and design of pile foundations.

关 键 词：桩基础 大直径管桩 纵向振动 连续介质模型 横向惯性效应 施工扰动 

分 类 号：TU473[建筑科学—结构工程]