大跨度多塔斜拉桥具有规模庞大和结构复杂的特点,对于其动力特性分析显得尤为重要。本文以建成的嘉绍大桥主航道桥为研究对象,采用有限元软件Ansys分析其动力特性,最终得到了它所固有的动力特性。并通过与其他传统双塔斜拉桥进行对比,进一步分析了多塔斜拉桥的结构特点。分析结果能为桥梁结构的抗风、地震等动力计算提供基础,并且能为桥梁的施工控制和运营阶段的健康监测提供重要依据。 Large-span multi-tower cable-stayed bridge with large-scale and complex structure characteristics, the dynamic characteristics of the analysis is particularly important. In this paper, the main channel bridge of Jiashao Bridge built is taken as the research object, the dynamic characteristics of the main channel bridge are analyzed by the finite element software Ansys, and finally its inherent dynamic characteristics are obtained. And by comparing with other traditional double-tower cable-stayed bridges, the structural characteristics of multi-tower cable-stayed bridges are further analyzed. The results of the analysis can provide the foundation for dynamic calculation of wind-resistance and earthquake of bridge structure, and provide an important basis for the health monitoring during construction control and operation of the bridge.