基于长期监测数据的斜拉索索力及异常振动自动识别及分析

Identification and Analysis of Cable Force and Abnormal Vibration of Stay Cables Based on Long-term Monitoring Data

监测斜拉索振动状态是斜拉桥监测的重要内容。本文以一座斜拉桥为依托,基于采集的斜拉索长期振动响应和环境监测数据,采用频率自动识别方法和基于频率的索力计算方法,自动识别斜拉索在不同服役环境下的基频、索力和加速度均方根,并分析基频、索力和加速度均方根与环境因素的关系。结果表明,斜拉索基频并不是定值,而是在很小范围内波动;当温度和风速变化很小时,斜拉索基频和索力变化不大,几乎不受温度和风速影响;风速对加速度均方根影响较大,说明风速是斜拉索振动快慢的主要影响因素,在日常监测中,不同风环境下的斜拉索振动监测应该成为斜拉索监测的重点。

Monitoring the vibration state is the key work in the monitoring of stay cables.This study proposes a case study based on the long-term monitoring data of a cable-stayed bridge.The fundamental frequency of the stay cable is identified using the peak picking method.The root mean square of the acceleration is calculated to identify the vibration state of the stay cable.The correlations between the fundamental frequency,cable force and RMS and the wind and temperature are analyzed.The results show that the fundamental frequency is not static and varies within a small range.The wind is the key factor that influences the vibration of the stay cable seriously.In general monitoring,the vibration of stay cables under wind environment should be treated as the key point.