摘要
为分析双向非均质土中大直径管桩纵向振动特性,基于Rayleigh-Love杆件模型和Novak平面应变理论,综合考虑大直径管桩桩体横向惯性效应以及桩侧土体施工扰动效应的影响,建立径向非均质、纵向成层土中大直径管桩纵向振动力学模型。通过Laplace变换和复刚度传递法,求解出土体与大直径管桩接触面处的复刚度表达式,进而采用桩–土完全耦合条件和阻抗函数传递性,推导得出简化模型对应的桩顶动力阻抗解析解答,并与已有相关解析解进行退化对比分析,以验证其合理性。在此基础上,进一步参数化分析桩土各类参数对大直径管桩动力阻抗的影响规律。结果表明:(1)Euler-Bernoulli杆模型低估了阻抗曲线振幅和共振频率,宜采用Rayleigh-Love杆件模型和所得相关解析解答分析大直径管桩纵向振动特性。(2)大直径管桩桩体内(外)径不变情况下,外(内)径越大(小),桩顶动力阻抗曲线振荡幅值和共振频率越高。(3)桩侧土体纵向夹层越软(硬),其动力阻抗曲线大小峰值差幅度越大。(4)桩侧土径向软(硬)化程度越大,桩顶动力阻抗振幅和共振频率越大(小)。扰动范围仅对动力阻抗振幅影响显著,而对共振频率的影响基本可以忽略。
In order to investigate the vertical vibration characteristics of large-diameter pipe piles embedded in bidirectional inhomogeneous soils,a mechanical model for longitudinal vibration of large-diameter pipe piles in radial inhomogeneous layered soils is established by considering the lateral inertia effect of large-diameter pipe piles and construction disturbance,based on the Rayleigh-Love rod model and Novak’s plane-strain theory.The complex stiffness expression at the interface between the soil and the large-diameter pipe pile is obtained recursively by means of the Laplace transform and complex stiffness transfer techniques.Then the analytical solution for the dynamic impedance of large-diameter pipe piles is derived by using the completely coupling condition between pile and soil and the transitivity of the impedance function,and compared with the previous solutions to verify the validity and precision.Furthermore,parametric analyses are performed to investigate the effects of the parameters of pile and soil on the dynamic impedance of a large-diameter pipe pile.The results show that the Rayleigh-Love rod model and the relevant analytical solution are more appropriate to analyze the longitudinal vibration characteristics of large-diameter pipe piles than Euler-Bernoulli rod model which underestimates the amplitude and resonance frequency of the dynamic impedance.Keeping the inner(outer)diameter constant,the larger(smaller)the outer(inner)diameter,the higher the amplitude and resonance frequency of the dynamic impedance at the pile head.The softer(harder)the longitudinal interlayer of the surrounding soil,the larger the peak difference of the dynamic impedance curves.The greater the degree of softening(hardening)of the surrounding soil,the larger(smaller)the amplitude and resonance frequency of the dynamic impedance at the pile head.The disturbance range has a significant effect on the oscillation amplitude while little influence on the resonance frequency.
作者
梁志孟
崔春义
许成顺
辛宇
孟坤
裴华富
LIANG Zhimeng;CUI Chunyi;XU Chengshun;XIN Yu;MENG Kun;PEI Huafu(Department of Civil Engineering,Dalian Maritime University,Dalian,Liaoning 116026,China;Key Laboratory of Urban Security ami Disaster Engineering of Ministry of Education,Beijing University1 of Technology,Beijing 100124,China;State Key Laboratory of Coastal and Offshore Engineering,Dalian University of Technology,Dalian,Liaoning 116024,China)
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2021年第9期1933-1944,共12页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金面上项目(51878109)
辽宁省航运联合基金项目(2020–HYLH–48)
“双一流”建设专项资金项目(BSCXXM022)。
关键词
桩基础
大直径管桩
纵向阻抗
双向非均质
横向惯性效应
复刚度传递
pile foundation
large-diameter pipe pile
longitudinal impedance
bi-directional inhomogeneity
lateral inertia effect
complex stiffness transfer
