以遭受2007年9月韦帕台风袭击的润扬长江大桥南汉悬索桥为例,利用该桥结构健康监测系统(SHMS)中加速度传感器实时采集的数据,结合台风期间专门增设的三维超声风速仪实测数据,采用时频分析和统计方法对大跨悬索桥的风特性及抖振响应进行了现场实测研究,主要研究内容包括桥址区的强风特性分析、主梁和缆索振动响应特性分析、振动与风速的相关性、斜风分解的影响等,并将其与台风麦莎期间的实测结果进行了对比分析。研究结果可用于验证现有抖振理论分析方法的可靠性,为大跨度悬索桥的抗风设计提供参考。
Field measurements on buffet responses of existing bridges have great significance on the development of bridge wind engineering. The typhoon Wipha passed through Jiangsu in September 2007. In this paper, Runyang suspension bridge (RSB) attacked by typhoon Wipha is taken as an example. Based on the data monitored by accelerometers of structural healthy monitoring system (SHMS) of RSB and 3-D sonic anemometer installed during typhoon Wipha, the field experiment studies on wind characteristics and buffet responses of long-span suspension bridges were conducted using the time-frequency technique and statistical theory. The measurement data are analyzed to obtain the wind characteristics, the response characteristics of cable and deck, the variation of acceleration response RMS vs. wind velocity, the influence of skew wind decomposition, etc. The results are compared with the field measurement results during typhoon Matsa. Results obtained can be employed to validate the reliability of current buffet response calculation techniques, and provide reference values for wind-resistant design of long-span suspension bridges.