斜风作用下大跨度桥梁抖振响应时域分析(II):现场实测验证

Time-domain analysis on buffeting response of long span bridge under oblique winds(II): field measurement validation

既有桥梁抖振响应的现场实测研究工作对桥梁风工程的发展具有重要价值。以遭受'麦莎'台风袭击的润扬悬索桥为工程背景,在对该桥结构健康监测系统(SHMS)中振动监测子系统进行介绍的基础上,利用'麦莎'台风期间加速度传感器实时采集的振动响应数据对大跨度悬索桥的抖振响应进行现场实测研究,其中采用频普分析和统计方法重点研究主梁和缆索的抖振响应特征。同时将其与有限元数值模拟结果进行对比,验证基于改进的斜风分解法的大跨度桥梁抖振响应时域分析方法的可靠性和有效性,分析大跨度悬索桥抖振响应的机理。结论可为其他大跨缆索承重桥梁的抗风设计与研究工作提供参考。

Field measurement of the buffeting response of existing bridges is valuable to bridge wind engineering. The Runyang Suspension Bridge （RSB） under typhoon Matsa is employed as an example. After introducing the vibration monitoring subsystem of the structural health monitoring system （SHMS） for RSB, a study of field measurement of the buffeting response of long span suspension bridges are conducted by using the real-time vibration response measurement data recorded by accelerators of SHMS during typhoon Matsa. Among other things, vibration response of the deck and the main girder is specially analyzed by using the frequency spectrum technique and the statistical theory. The field measurement data are compared with the calculation results, and the buffeting response time-domain analysis method for long span bridges, based on the modified oblique wind decomposition approach, is validated, and the buffeting response mechanism and theory of long span suspension bridges are analyzed. The results may serve as reference for the wind- resistant design and study of other long span cable-stayed bridges.