考虑桩土非完全粘结及桩底土波动效应的浮承桩纵向振动特性研究  

Vertical vibration characteristics for floating pile considering the incomplete bonding condition of pile-soil and the wave propagation effect of soil beneath pile

作　　者：孟坤[1,2] 崔春义 许成顺[3] 姚怡亦[1] 辛宇 梁志孟[1] MENG Kun;CUI Chun-yi;XU Cheng-shun;YAO Yi-yi;XIN Yu;LIANG Zhi-meng(Department of Civil Engineering,Dalian Maritime University,Dalian 116026,China;College of Transportation,Shandong University of Science and Technology,Qingdao 266590,China;Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education,Beijing University of Technology,Beijing 100124,China)

机构地区：[1]大连海事大学土木工程系,辽宁大连116026 [2]山东科技大学交通学院,山东青岛266590 [3]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

出　　处：《振动工程学报》2023年第2期435-444,共10页Journal of Vibration Engineering

基　　金：国家重点研发计划资助项目(2021YFB2601102);国家自然科学基金面上项目(52178315,52108326)。

摘　　要：为合理考虑浮承桩纵向振动问题中桩端土作用及桩-土界面相对位移条件,同时引入动力Winkler模型和虚土桩模型,建立了一种适用性更广的浮承桩纵向振动特性研究方法。引入分离变量法对三维土体位移控制方程进行求解,结合土体表面及基岩处边界条件得到三维土体位移基本解;通过将动力Winkler模型相关参数考虑为桩-土界面边界条件在频域内解析求解了桩纵向振动特性,并将所得频域解析解拓展到时域,采用离散傅里叶逆变换方法(IFT)求解了桩顶速度时域响应;开展参数化分析探讨了桩-土界面非完全粘结条件及虚土桩参数对浮承桩动力响应的影响,计算结果表明:桩-土界面完全耦合假定会过高估计桩侧土对桩的约束作用,无法合理评估桩基的抗振性能,并会对桩基抗振防振设计及桩底反射信号识别产生不利影响;另外,针对浮承桩纵向振动问题,采用虚土桩模型描述其桩底土作用具有合理性和必要性。Based on dynamic Winkler model and fictitious soil pile model to consider the relative sliding at pile-soil interface and the propagation effect of soil beneath pile toe,respectively,the dynamic interaction system for a floating pile with incomplete bonding condition embedded in three-dimensional continuum is established.The separation variable method is introduced to solve the threedimensional soil displacement control equation.Combined with the boundary conditions of soil surface and bedrock,the general so⁃lution of soil displacement is obtained.Considering the relevant parameters of the dynamic Winkler model as the boundary condi⁃tion of the pile-soil interface,the longitudinal vibration characteristics of the pile are solved analytically in the frequency domain,and the obtained frequency domain analytical solution is extended to the time domain.The time domain response of the velocity is solved by using the inverse Fourier transform(IFT).Extensive parametric analyses are performed to investigate the effects of in⁃complete bonding condition at pile-soil interface and parameters of fictitious soil pile.The results show that the assumption of com⁃plete coupling of pile-soil interface may overestimate the restraint effect of pile surrounding soil on pile,which has an adverse im⁃pact on the anti-vibration design of pile foundation and the identification for reflected signal of pile toe.In addition,for the longitudi⁃nal vibration of floating bearing pile,it is reasonable and necessary to use the fictitious soil pile model to describe the soil action un⁃der the pile.

关 键 词：桩底土 虚土桩 桩-土相对滑移 动力阻抗 解析解 

分 类 号：TU473.1[建筑科学—结构工程]