小西湖矮塔斜拉桥的动力性能分析

以小西湖矮塔斜拉桥为例,通过引入拉索自振频率影响度的概念,分析了拉索的存在对矮塔斜拉桥自振特性的影响,探讨了矮塔斜拉桥的自振特性与相应连续梁桥(或刚构桥)的区别;在分析矮塔斜拉桥地震反应的基础上,通过引入振型贡献率的概念,分析了高阶振型对矮塔斜拉桥动力性能的影响;分析了矮塔斜拉桥的振型耦联效应.最后较全面地总结了单索面混凝土矮塔斜拉桥的动力特性,对进一步认识矮塔斜拉桥的动力性能有一定的参考意义.

Dynamic Property of Xiaoxihu Concrete Extradosed Cable-stayed Bridge

The concept of influence degree of natural vibration period by cables is shown,and the influence of cables to the property of natural vibration of extradosed cable-stayed bridges is analyzed by taking Xiaoxihu extradosed cable-stayed bridge in Lanzhou City as an example.The difference of natural vibration property of extradosed cable-stayed bridges to correspondingly continuous beam(or rigid frame) is investigated.Then,based on the seismic reaction of example bridge,a concept of contributing degree of vibration mode is presented,and the influence of high-order vibration modes to dynamic property of extradosed cable-stayed bridges is analyzed.Furthermore the coupled effect of vibration modes of extradosed cable-stayed bridges is analyzed.In the end,dynamic properties of concrete extradosed cable-stayed bridges with single cable plane are presented comprehensively for the first time.These results have reference value for deeply understanding of the dynamic properties of extradosed cable-stayed bridges.