Abstract: The natural frequency and vibration mode are the principal modal parameters for representing structure dynamic behavior and the impeaant basis for evaluating bridge dynamic performance．A three-dimensional finite element model for single pylon cable-stayed bridge with ANSYS procedure Was created to analyze the dynamic performan ce of Shizhou Cable-Stayed Bridge in Enshi City．The result enunciates that the torsion modal appears early，and the lord across eonseeution with extension makes the lord across horizontal benting of the first modal，which could serve as reference for the analysis of dynamic behavior of similar bridges．

Key words: single-column pylon of single-cable-plane-cable-stayed bridge, finite element model, dynamic characteristics

摘要： 固有频率和振型是反映桥梁动力特性的主要模态参数，是评价桥梁动力性能的重要依据．应用ANSYS程序，建立 了施州大桥独塔单索面斜拉桥的三维空间有限元模型，开展了动力特性分析．结果表明，扭转振型出现较早，主跨与延 伸跨连续，使大桥一阶振型呈主跨侧向弯曲的特点、为同类型桥梁的动力特性分析提供参考．

关键词: 独塔单索面斜拉桥, 有限元模型, 动力特性