大跨度钢箱梁与组合梁天桥舒适度对比研究

Comparative Study on Comfort of Large-Span Pedestrian Bridge with Steel Box Girder and Steel-Concrete Composite Girder

借鉴《城市人行天桥与人行地道技术规范》征求意见稿及其所参考的法国SETRA及德国HiVoSS关于行人舒适度评价标准,采用MIDAS有限元软件建模验算的方式,对1×40 m跨径的大跨度简支人行天桥在钢箱梁与刚度较大的钢-混凝土组合梁两种不同结构形式下的设计基频进行比较,并通过时程分析法研究两种截面形式在同一跨径不同刚度下,其基频所对应的最大加速度峰值与舒适度评价所对应的峰值加速度限值之间的关系,进而对不同结构形式的大跨度人行天桥进行行人舒适度评价分析。结果表明:较之常见的钢箱梁结构形式,大跨度简支钢箱梁人行天桥选用刚度较大的钢-混凝土组合梁截面形式并不能有效提高其竖向基频,但可以有效提高其整体行人舒适度。

Referring to the exposure draft of“Technical Specification for Urban Pedestrian Bridge and Pedestrian Tunnel”and the evaluation standard for pedestrian comfort referred to by SETRA of France and HiVoSS of Germany,the method of MIDAS finite element software modeling and checking is adopted.The design fundamental frequency of a large-span simple supported pedestrian bridge with a span of 1×40 m is compared under two different structural forms of steel box girder and steel-concrete composite girder with larger stiffness.The relationship between the peak acceleration corresponding to the fundamental frequency and the peak acceleration limit corresponding to the comfort evaluation of the two cross section forms under different stiffness of the same span is studied by time-procedure analysis.Then it evaluates and analyzes the pedestrian comfort of the large span pedestrian bridge with different structure forms.The results show that compared with the common steel box girder structure,the steel-concrete composite beam section with higher stiffness can not effectively improve the vertical fundamental frequency of the large-span simple supported steel box girder pedestrian bridge,but can effectively improve the overall pedestrian comfort.