边中跨比及无索区长度对独塔斜拉桥静动力影响

Influence of Ratio of Side-Span to Mid-Span and Length of Unsupported Deck on Static and Dynamic Performance of Single Pylon Cable-Stayed Bridges

以南充市区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、主梁无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。

Based on the constructed single pylon cable-stayed main bridge of Shangzhongba Jialingjiang Bridge in Nanchong,finite element calculation models were established. 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-span to mid-span and the length of unsupported deck. Both 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 little contribution to inherent vibration characteristics. Conclusions are drawn to optimize the structure design of the cable-stayed bridge.