大跨异型玻璃悬索人行桥侧向振动临界人数估计

摘要

随着人行天桥更多采用轻型材料和新颖结构,结构形式变更"轻"、更"新"、更"美",跨径变更的更"大",但由行人激励导致的振动及带来的行走舒适性甚至结构安全性问题也相继日益突出.为得到某大跨异型玻璃悬索人行桥可能引起横向动力失稳的临界人数,首先通过有限元方法对人行桥动力特性进行分析,并通过实测对动力特性计算结果进行对比验证;进一步,推导了该桥侧向振动动力失稳的临界人数估算公式,并比较了频率、振型等动力特性参数对计算结果的影响;最终,得到了大桥可能发生动力失稳的临界人数.研究结果可供该桥的运营管理提供参考,估算方法也可供类似工程借鉴.%With the progress of ever-increasing span of footbridges and the application of modern light and high strength materials,as well as the fundamental frequency of modern flexible footbridges decreases significantly,pedestrian-induced vibration,particularly the lateral vibration,has become one of the hot topics especially.In the present study,in order to obtain the critical pedestrian number of a large span irregular pedestrian suspension glass bridge,the dynamic characteristics of the pedestrian bridge was analyzed by finite element method firstly,which were verified by field measurement.Then,derivation of the formula for calculating critical pedestrian number,which may cause lateral vibration dynamic instability,was presented,and the influence of the dynamic characteristic parameters such as frequency and mode on the calculation results were compared.Finally,the critical pedestrian number was obtained.The results of the study can provide reference for the operation and management of the bridge,and the estimation method can also be used for reference for similar projects.