公铁两用斜拉桥竖向动力特性长期监测分析

Long-term Monitoring and Analysis of Vertical Dynamic Characteristic of Rail-cum-road Cable-stayed Bridge

基于黄冈公铁两用斜拉桥健康监测系统2015年1月—9月的主梁竖向加速度长期监测数据,分析了桥梁竖向振动的长期频谱特征,研究了桥梁竖向动力特性与温度的相关性,得到了桥梁竖向振动前4阶固有频率与环境温度的相关性拟合曲线,给出了桥梁竖向动力特性在长期服役过程中的预警阈值。研究结果表明:黄冈公铁两用斜拉桥主梁的竖向振动固有频率与温度具有明显的线性相关性;根据桥梁竖向振动的归一化频率与桥梁监测数据所识别频率的残差,能够有效制定桥梁竖向动力特性预警指标,以用于桥梁服役过程中的动力性能长期监测。

Based on the long-term monitoring data（from January to September 2015） of girders vertical acceleration on the structure health monitoring system of the Huanggang rail-cum-road cable-stayed bridge,the longterm spectral performance of bridge vertical vibration was analyzed.The correlation between the vertical dynamic characteristic of bridge and the environmental temperature was studied,and the fitting curves of which were presented.The early warning thresholds of bridge vertical dynamic characteristic in serving were given in this paper.The results show that he natural frequencies of vertical vibration at the main girder of the Huanggang rail-cum-road cable-stayed bridge have significant linear correlation with temperature.The residual of the normalized frequency and measured frequency can effectively make a contribution to the early warning indicators of vertical dynamic characteristic of bridge,which can be used for the long-term monitoring of the dynamic characteristic of bridge in service.