南京大胜关长江大桥主梁加速度响应的长期监测与分析

Long-term Monitoring and Analysis on Main Girder Acceleration Response of Nanjing Dashengguan Yangtze River Bridge

针对现有规范对铁路桥梁的振动加速度限值不适用于大跨度高速铁路桥梁的情况,本文通过分析南京大胜关长江大桥桥梁结构健康监测系统长期监测得到的桥梁结构响应数据,研究列车过桥工况下主梁振动加速度峰值的变化规律,并与车速、轴重进行相关性分析。研究结果表明:在单一列车过桥工况下,主梁加速度峰值集中在固定的变化区间,且服从正态分布;桥梁振动加速度峰值与车速不存在线性相关性,与列车轴重存在线性相关性;动应变响应有叠加交汇工况下,加速度峰值约为单一列车过桥工况的1.4倍;现有运营条件下,大胜关桥梁振动加速度响应正常,能保证列车的行车安全。

In view of the fact that the limit value of vibration acceleration of railway bridge in the existing code is not suitable for the long span high speed railway bridge,the change rule of the peak vibration acceleration of the main girder under the condition of train passing through the bridge was studied by analyzing the long-term monitoring data of the bridge structure health monitoring system of Nanjing Dashengguan Yangtze River Bridge,the correlations between peak vibration acceleration and vehicle speed and axle load were analyzed.The results show that under the condition of single train crossing the bridge,the peak acceleration of the main girder is concentrated in the fixed change range and obeys the normal distribution.There is no linear correlation between the peak vibration acceleration of the bridge and the vehicle speed,and there is linear correlation between the peak vibration acceleration and the axle load of the train.Under the condition of superposition of dynamic strain response,the peak acceleration is about 1.4 times of the condition of single train crossing the bridge.Under the existing operation conditions,the vibration acceleration response of Dashengguan bridge is normal,which can ensure the safety of train operation.