摘要
将多塔悬索桥的中塔当作底部固定、顶部受到主缆弹性约束的结构,在Rayleigh能量法和Southwell's频率合成法的基础上,推导了受到主缆约束的桥塔结构振动基频近似计算表达式。以成桥后的泰州大桥中塔为例,测试了其环境激励下的自振基频,并对环境激励下桥塔的自振基频与其理论计算结果进行了对比分析。结果表明:该基频表达式不仅可在设计阶段预估桥塔的振动特性,还可在桥梁运营期通过频率测试来识别塔顶的顺桥向抗推刚度。且计算基频与实测值的误差为4.46%～5.48%,在可接受范围。该算法不仅适用于各种复杂截面多塔悬索桥中塔,也适用于挂线的输电塔等工程结构。
The middle pylon in multi-pylon suspension bridge is simplified as a structure which is elastically constrained by cables at its top. Based on the combination of Rayleigh and Southwell methods, an approximate expression to calculate vibration fundamental frequency of a pylon constrained by main cables is derived. The fundamental frequency of natural vibration in ambient vibration of middle pylon of Taizhou Bridge after completion is tested, which is compared with the calculation result. The result shows that （1） the expression not only can estimate the vibration properties of pylon in design phase, but also can identify the longitudinal anti-pushing rigidity of pylon top through the operational measurement of frequency; （2） the errors between the calculative and measured results are 4. 46% ~5. 48% which are in the acceptable range. The algorithm is not only suitable for middle pylon with complicated cross-section in multi-pylon suspension bridges, but also suitable for power transmission tower system.
出处
《公路交通科技》
CAS
CSCD
北大核心
2013年第8期108-112,共5页
Journal of Highway and Transportation Research and Development
基金
江苏省交通科学研究计划项目(08Y29)
江苏省高校自然科学研究计划面上项目(11KJB560002)
关键词
桥梁工程
多塔悬索桥
基频近似算法
Rayleigh法和Southwell合成法
桥塔
bridge engineering
multi-pylon suspension bridge
approximate algorithm to calculate fundamental frequency
combination of Rayleigh and Southwell methods
pylon
