张弦桥结构静力分析方法与受力特点研究  

Study on Static Structural Analysis Method and Mechanical Characteristics of String-tensioned Bridge

作　　者：周光伟 钱长照 ZHOU Guang-wei;QIAN Chang-zhao(School of Civil Engineering and Architecture,Xiamen University of Technology,Xiamen Fujian 361024,China)

机构地区：[1]厦门理工学院土木工程与建筑学院,福建厦门361024

出　　处：《公路交通科技》2020年第12期63-69,共7页Journal of Highway and Transportation Research and Development

基　　金：国家重点研发计划项目(2017YFC0806000)。

摘　　要：张弦桥作为一种新型组合体系桥梁,其结构力学特点与分析方法有待进行深入的研究。为了研究张弦桥静力分析方法与受力特点,首先根据张弦桥的结构特点,采用弹性方法和挠度理论的等代梁方法提出了张弦桥的结构静力分析方法,对两种理论方法计算结果进行了比较分析,推导了张弦桥在全跨对称均布荷载、半跨非对称荷载以及跨中集中荷载布置等3种典型荷载工况下主梁内力和位移的计算公式。基于张弦桥工程实例建立了2种有限元分析模型:主缆分别采用弹性桁架单元模型和非线性索单元模型。分析了采用不同主缆单元类型、不同索力大小对结构内力和位移计算结果的影响。结果表明:在基于一定假定的前提下,弹性方法和等代梁方法的计算结果是一致的;和普通简支梁桥相比,张弦桥能较大地减小主梁跨中弯矩与位移,主梁内力与位移的主要影响因素为主缆的矢高;采用不同主缆单元类型的有限元分析结果相同,张弦桥主缆在不同索力工况下,主梁弯矩与位移增量与主缆张拉的索力无关,张弦桥主缆非线性影响较小,张弦桥结构具有弹性受力的特点;推导的内力位移计算公式与有限元方法计算结果差值均小于9%,具有一定的工程应用精度。As a new type of composite bridge,the structural mechanical characteristics and analysis method of the string-tensioned bridge need to be further studied.In order to study the static analysis method and mechanical characteristics of string-tensioned bridge,firstly,according to the structural characteristics of this type of bridge,the static structural analysis method of string-tensioned bridge is put forward based on the elastic method and the equal-substitute beam method in deflection theory.The calculation results of the 2 methods are comparatively analyzed,and the calculation formulas of internal force and displacement of the main girder under 3 typical loading conditions(full span symmetric uniform load,half span asymmetric load,and concentrated load in mid-span)are derived.Two kinds of FE analysis models are established based on the example of the bridge project:one is the elastic truss element model and the other is the nonlinear cable element model for the main cable.The influences of different element types and different cable forces of the main cable on the calculation result of the internal force and displacement of the structure are analyzed.The result shows that(1)Based on a certain assumption,the calculation results of the elastic method and the equivalent beam method are consistent.(2)Compared with ordinary simply supported beam bridges,the string-tensioned bridge can greatly reduce the bending moment and displacement of the main girder at mid-span,and the main influence factor of the internal force and displacement of the main girder is the rise of the main cable.(3)The results of the FE analysis using different main cable element types are the same.Under different cable forces,the increments of the bending moment and displacement of the main girder have nothing to do with the tension of the main cable,the nonlinear effect of the main cable of the bridge is small,and the structure of the bridge has the elastic force characteristics.(4)All the difference of the calculation results between the derive

关 键 词：桥梁工程 受力特点 等代梁方法 张弦桥 结构静力分析 

分 类 号：TU393.3[建筑科学—结构工程]