某大跨度钢结构人行天桥设计

Design of a Large-span Steel Structure Footbridge

基于某大跨径钢结构人行天桥的设计,比选了几种提高结构竖向自振频率的措施。通过计算分析得出增加梁高、翼缘板厚度等方法,既不经济也不美观,而且其竖向自振频率变化不大;而采用墩梁固接方式虽效果明显但由于地质复杂等原因本项目未采用。最后提出了采用附加阻尼器减小结构振动的设计方法,并计算分析了天桥减振前后人致共振的最大加速度响应结果,从理论上说明了其优越性。最后通过成桥调试,验证了理论计算的结果,以供类似工程参考。

Based on the design of a long-span steel structure pedestrian bridge,several measures to increase the vertical natural frequency of the structure are compared.Through calculation and analysis,it is found that methods such as increasing the beam height and flange plate thickness are not economical or aesthetically pleasing,and the vertical natural frequency of the beam does not change much.However,the pier-beam fixed method has obvious effects,but due to geological complexity and other reasons.The project was not adopted.Finally,a design method for reducing structural vibration with an additional damper is proposed,and the results of the maximum acceleration response of human-induced resonance before and after vibration reduction of the flyover are calculated and analyzed,which theoretically illustrates its superiority.Finally,the results of theoretical calculations were verified through bridge commissioning for reference in similar projects.