裹覆隔振层的实心桩纵向振动特性研究  

Vertical vibration characteristics of solid pile with vibration isolation layer

作　　者：邓世邦 罗威力 DENG Shi-bang;LUO Wei-li(School of Civil Engineering,Guangzhou University,Guangzhou,Guangdong 510000,China)

机构地区：[1]广州大学土木工程学院,广东广州510000

出　　处：《岩土力学》2024年第10期3081-3094,共14页Rock and Soil Mechanics

基　　金：国家自然科学基金面上项目(No.52178323);广东省基础与应用基础研究基金自然科学基金项目面上项目(No.2023A1515012865)。

摘　　要：为分析实心桩裹覆隔振材料后的纵向振动特性,基于Rayleigh-love杆件模型和Novak平面应变理论,综合考虑桩周振动传播介质的径向和纵向非均匀性以及桩身横向惯性效应,建立了桩周振动传播介质-实心桩耦合作用纵向动力阻抗解析模型。利用Laplace变换、复刚度传递和阻抗函数传递法,得到黏性阻尼介质中任意竖向荷载作用下实心桩桩顶动力阻抗的解析解答,并与已有解析解答对比验证其合理性。通过现场试验发现,桩顶动刚度幅值的大小对桩顶动力响应有明显影响,两者之间高度相关。在此基础上,研究了橡胶隔振层不同厚度和纵向深度以及隔振层材料种类变化对实心桩桩顶动刚度的影响。结果表明,在1~80 Hz频段内:(1)随着橡胶隔振层厚度的增加(减小),动刚度幅值曲线会向低频(高频)移动,但整体上厚度变化对特征频率和动刚度幅值的影响较小;(2)随着橡胶隔振层纵向深度的增加(减小),动刚度幅值曲线的振荡幅度和振荡频率也会随之明显提高(降低);(3)当采用剪切模量小于桩周土体的隔振材料时,随着剪切模量的减小,动刚度幅值曲线的振荡幅度和振荡频率也会随之提高;(4)当采用剪切模量大于桩周土体的隔振材料时,随着剪切模量的增大,动刚度幅值曲线的振荡属性基本消失,且整体会出现小幅抬升。To analyze the vertical vibration characteristics of a solid pile with vibration isolation layer,a vertical dynamic impedance analytical model of the vibration propagation medium and the solid pile was established.The model was based on the Rayleigh-love rod model and Novak plane strain theory,considering the radial and longitudinal non-uniformity of the vibration propagation medium around the pile and the lateral inertia effect of the pile.Utilizing the Laplace transfer method,complex stiffness transfer method,and impedance function transfer method,the analytical solution of dynamic impedance at the solid pile head under arbitrary vertical load in a viscous damping medium was derived.The rationality of this solution was verified by comparing with the existing analytical solution.It is found that the amplitude of the pile head dynamic stiffness has an obvious influence on the dynamic response at the pile head,indicating a high correlation.Further,the effects of different thicknesses and longitudinal depths of the rubber layer and different types of vibration isolation material on the pile head dynamic stiffness are investigated.The results show that in the frequency range of 1-80 Hz:(1)The dynamic stiffness curve shifts to a lower(higher)frequency as the rubber layer thickness increases(decreases),with the thickness variation having an insignificant effect on the feature frequency and the dynamic stiffness;(2)The amplitude and oscillation frequency of the dynamic stiffness curve increase(decrease)significantly as the rubber layer longitudinal depth increases(decreases);(3)When the vibration isolation material is softer than the surrounding soil,the amplitude and oscillation frequency of the dynamic stiffness curve increase as the shear modulus of the vibration isolation material decreases;(4)When the vibration isolation material is harder than the surrounding soil,the amplitude of the dynamic stiffness curve slightly increases as the shear modulus of the vibration isolation material increases,and the oscillatory

关 键 词：桩基础 地铁振动 隔振 复刚度传递 动力阻抗 

分 类 号：TU473[建筑科学—结构工程]