【摘要】 佛开高速九江大桥全长1819.16m,主桥采用六孔一联、最大跨度160m的变截面预应力砼连续箱梁。为实时监测桥梁结构振动状况和记录大型桥梁真实地震反应,在九江大桥主桥上架设了总计23通道的强震动监测系统。简要介绍了该监测系统的测点布置、系统构成和技术特点,并对系统试运行期间的加速度记录进行了峰值、频谱和模态分析,得到了箱梁前六阶模态频率变化曲线,并与现场实测模态参数进行了比较验证。研究识别出的模态频率的长期变化可以为桥梁结构的健康监测和损伤评估提供参考依据。更多还原

【Abstract】 Jiujiang bridge in Fokai highway has a total length of 1 819.16m and its main part is a prestressed reinforced concrete continuous bridge with variable cross-sections and a main span of 160 m.To monitor its real-time vibration and capture possible real earthquake responses of the bridge,a vibration monitoring system comprising 23-channel accelerometers has been set up at its main part.The location of sensors,equipments and technical feature of the monitoring system are briefly introduced in this paper.The recorded acceleration data during the test run period are analyzed to study the variations of peak acceleration,Fourier frequency and modal frequencies of each channel.The first six modal frequencies of the main beam have been obtained daily and compared with previous modal test results of the bridge.It is believed that studying the long-term variation of these modal parameters will provide helpful references to bridge health monitoring and damage evaluation.更多还原