大跨多线高速铁路钢桁拱桥车——桥振动安全预警研究

Research on Safety Early Warning of Vehicle-Bridge Vibration for Long-Span Multi-Track Steel-Truss Arch Bridge of High Speed Railway

基于南京大胜关长江大桥健康监测系统,对高速列车行车工况下大跨多线铁路桥梁的振动响应进行在线识别。根据大跨多线铁路桥振动加速度幅值会在1个或多个车速点存在明显峰值的特征,提出基于小波包分解法和区间估计理论的车—桥振动安全预警方法。依据不同行车工况下桥梁振动加速度响应幅值、高速列车车速的相关性,采用小波包分解法提取反映桥梁结构振动加速度幅值随车速变化的桥梁加速度幅值在列车车速坐标上的中值线;采用区间估计理论,得到反映桥梁运营过程中桥上列车载客量和轨道不平顺状况等随机因素对车—桥振动影响的桥梁加速度幅值围绕中值线的波动区间;最终基于加速度幅值—车速中值线和加速度幅值波动区间,实现运营中大跨多线高速铁路钢桁拱桥车—桥振动性能的安全预警。

Based on the health monitoring system of theNanjing Dashengguan Yangtze River Bridge,the vibration responses of the long-span multi-track railway bridge are online identified under the operation conditions of G-series high-speed train.According to the features that the vibration acceleration amplitude of the long-span multi-track railway bridge has significant peak at one or more train-speed points,a safety early warning method of vehicle-bridge vibration is put forward using wavelet packet decomposition and interval estimation theory.Based on the correlation features between theamplitude of bridge vibration acceleration response and the speed of G-series high-speed train under different operation conditions,the median line on the coordinates of bridge acceleration amplitude versus train speed is gained using wavelet packet decomposition method which reflects the amplitude of bridge vibration acceleration varying with train speed.The fluctuation interval of acceleration amplitude around the median line is obtained using interval estimation theory which reflects the influence of the carrying capacity of train on in-service bridge,track irregularity,and other random factors on the vehicle-bridge vibration.Finally,the safety early warning of vehicle-bridge vibrationisachieved for the in-service long-span multi-track steel-truss-arch high speed railway bridge based on the median line of acceleration amplitude versus train speed and the fluctuation interval of acceleration amplitude.