（1 中冶京诚工程技术有限公司， 北京 100176； 2 北京京诚华宇建筑设计研究院有限公司， 北京 100070；  3 梅溪湖投资（长沙）有限公司， 长沙 410205）

［摘要］长沙梅岭公园跨龙王港河步行桥形同中国结，主体结构采用随桥形同步变化的钢结构桁架体系，结构受力主次分明，传力明确。介绍了穿插交错处设置水平通道的结构实现方式、半穿式桥梁桁架结构上弦杆平面外计算长度的计算方法及步行桥施工安装顺序。针对此结构体系，进行了模态分析、弹性屈曲分析和施工阶段分析。结果表明，在主次桥体间采取增加上下拉结杆件，能加强整体结构竖向振动特性和增大竖向刚度，本结构整体稳定性能和施工安装顺序均能满足设计要求。

［关键词］步行桥； 中国结； 半穿式钢桁架结构； 计算长度； 施工安装顺序

中图分类号：TU393-3文献标识码：A文章编号：1002-848X(2017)07-0033-05

Structural design of Meiling Park Footbridge across Longwanggang River in Changsha

Yu Wenhua1,2， Lu Lijie1,2， Tan Jinpeng1,2， Yu Haiqun1,2， Zhang Huashuai3

（1 MCC Capital Engineering & Research Incorporation Ltd., Beijing 100176, China； 

2 CERI Architects & Engineers Co., Ltd., Beijing 100070, China； 

3 Meixihu Investment (Changsha) Co., Ltd., Changsha 410205, China）

Abstract:The Meiling Park Footbridge across  Longwanggang River in Changsha looks like the Chinese knot in shape. The steel structure truss system is applied as its main structure and the truss shape is changed along with the bridge shape. The structure is under actions of clear primary and secondary forces, and force transfer way is clear. The structural design of the horizontal channel set in intercrossed and overlapped parts was introduced. The calculation method of the out-of-plane effective length of top chords of half-worn typed steel truss structure was introduced. The construction installation sequence of the footbridge was described. The modal analysis, elastic buckling analysis and construction stage analysis were used to design the structural system. The analysis results show that adding some upper and lower pulling members between the primary and secondary bridges can improve the overall vertical vibration characteristics and increase the vertical stiffness of the footbridge. The overall stability and the construction installation sequence of the structure can meet the design requirements.

Keywords:footbridge; Chinese knot; half-worn typed steel truss structure; effective length; construction installation sequence

作者简介：余文华，硕士，工程师，Email：yuwenhua@ceri.com.cn。