中文摘要：

为方便计算独塔斜拉桥的振动基频,基于两跨独塔斜拉桥,应用Rayleigh法推导其竖弯振动基频公式,最后对此公式的可行性进行了算例验证,并讨论了该公式的适用对象及应用范围.研究结果表明：梁、塔及索截面形式对其竖弯振动频率没有影响,而支承条件对斜拉体系的竖弯频率影响较大;给出的基于能量法得到的纵飘基频计算值与有限元值误差能满足概念设计阶段的要求.

英文摘要：

In order to calculate fundamental frequency of the cable-stayed bridges with single tower conven- iently, the cable-stayed bridges with single tower is taken as research object, a fundamental frequency for- mula for vertical vibration mode of cable-stayed bridges is derived by the Rayleigh method, and the concept of nominal unity mass anti-bending rigidity is introduced. Finally, the presented theoretical formula of fun- damental frequency is validated by case study; and its suitabe objects and applicable range are discussed. The results indicate that the section types of the girder, tower and cable have no influence on the vertical frequency for vibration of cable-stayed bridges; but the supporting conditions have a great influence on ver- tical frequency of cable-stayed bridges. So it is necessary to consider the supporting conditions when calcu- lating frequency. The fundamental frequency calculated by the recommended method has a little error com- pared with the finite element method results, which meets the requirement of conceptive design.