斜向预应力混凝土铺面振动特性  

Vibration Characteristics of Cross-tensioned Concrete Pavement

作　　者：陈卉 凌建明[1,2] 赵鸿铎[1,2] 曾孟源 吴荻非 CHEN Hui;LING Jian-ming;ZHAO Hong-duo;ZENG Meng-yuan;WU Di-fei(Key Laboratory of Road and Traffic Engineer ing of the Ministry of Education,Tongji Univer sity,Shanghai 201804,China;Key Laboratory of Infr astructure Durability and Operation Safety in Airfield of CAAC,Tongji University,S hanghai 201804,China)

机构地区：[1]同济大学道路与交通工程教育部重点实验室,上海201804 [2]同济大学民航飞行区设施耐久与运行安全重点实验室,上海201804

出　　处：《中国公路学报》2020年第3期32-41,共10页China Journal of Highway and Transport

基　　金：国家自然科学基金项目(51778480,51978520);后勤开放科研项目(BKJ17J015)。

摘　　要：为了明确预应力影响下斜向预应力混凝土铺面的振动特性,并揭示预应力水平与振动特性的关系,首先开展足尺模型试验,通过分级张拉模拟不同预应力水平,并利用加速度计采集足尺模型振动数据,依托快速傅里叶变换捕获各预应力水平对应的振动特性,从而揭示预应力对斜向预应力混凝土铺面振动特性的影响。其次,利用ABAQUS软件建立斜向预应力混凝土铺面数值模型,通过等效荷载法模拟预应力作用,采集不同预应力水平下数值模型的加速度响应,并通过数值模拟拓展试验工况,开展参数(模量、密度、摩擦因数等)敏感性分析,进一步研究斜向预应力铺面振动特性及其变化规律。研究结果表明:预应力对振动主频影响较小,以主频为指标的传统方法在斜向预应力混凝土铺面振动分析中具有局限性,难以体现预应力影响下振动频谱的整体变化;预应力水平会显著影响50~150Hz频段的振动频谱分布,随着预应力增大,50~150Hz频段频谱曲线向高频呈现明显偏移,该频段权重频率变化量与预应力变化幅度具有显著的相关性;该规律在不同材料、摩擦因数等参数组合下具有一定普适性,进一步佐证预应力水平对权重频率具有显著影响,因此,建议采用权重频率作为指标以观测频谱分布的变化,从而分析预应力对斜向预应力混凝土铺面振动特性的影响。This paper aims to explore the effect of prestress force on the vibration characteristics of cross-tensioned concrete pavement(CTCP)using numerical simulation and field testing.A full-scale test was conducted and different prestress forces were simulated by grading tension.Accelerometers were used to collect the vibration data and Fast Fourier Transform analysis was introduced to obtain the vibration features.Then,finite element(FE)models of CTCP were built using ABAQUS to collect the acceleration and extract spectral features of the CTCP when subjected to different prestress forces.A parametric study was developed to evaluate the influence of parameters(i.e.modules,densities,and friction coefficients)on dynamic response.Test results show that the change in first-mode frequency is not obvious with increasing prestress force,indicating that the traditional vibration features cannot guarantee sufficient sensitivity to the prestress force of CTCP.However,the frequency band of 50-150 Hz under different prestress forces is much different compared with the low-frequency band.As the prestress force increases,the spectral components of the high-frequency band increase and the frequency curve gradually shifts to the right.A good correlation between the weighted frequency and the prestress force is also observed.Meanwhile,it was also found the spectral distribution is more sensitive to prestress force compared to other parameters,indicating that the prestress force can significantly influence the frequency band of 50-150 Hz.These works suggest that the weighted frequency can be employed to study the changes in the spectral distribution.The analysis of vibration characteristics can be used to identify the change in prestress force.

关 键 词：道路工程 斜向预应力混凝土铺面 振动分析 频谱 

分 类 号：U416.222[交通运输工程—道路与铁道工程]