Abstract: Based on the constructed single pylon cable-stayed main bridge o[ Shangzhongba Jialingjiang Bridge in Nanchong , finite element calculation models were estab!ished. Comparative calculation was carried out to tell the influence on the structure' s static and dynamic performance caused by two main factors , the ratio of side叩an to mid叩an and the length of unsupported deck. Bolh of them were analyzed separately to study the independent effect on the structure' s static and dynamic performance. Calculation results show that changes of the ratio of side-span to mid-span and the length of unsupported deck make an apparent contribution to the change of structure ' s static performance; however , the same changes make a !ittle contribution to inherent vibration characteristics. Conclusions are drawn to optimize the structure design of the cable-stayed bridge.

Key words: single pylon cable-stayed bridge, static performance, dynamic performance, the length of unsupported deck; ratio of side-span to mid-span

摘要： 以南充市民已建成的上中坝嘉陵江大桥主桥独塔斜拉桥为研究背景，建立了有限元对比分析计算模型，对边中跨比、主梁无索区长度两种参数进行单因素分析。计算结果表明:边中跨比、主梁元索区长度对结构静力特性有全面而深刻的影响，但对结构的固有振动特性影响却并不显著。分析结果可为斜拉桥的结构设计优化提供一定的 参考。

关键词: 独塔斜拉桥, 静力特性, 动力特性, 无索区长度, 边中跨比