基于实测应变的江阴长江大桥钢桥面板疲劳寿命评估

Fatigue Life Estimation of Steel Bridge Deck of Jiangyin Yangtze River Bridge Based on Measured Strain

基于实测应变,对江阴长江大桥正交异性钢桥面板构造细部疲劳寿命评估进行研究。利用实桥布设的应变传感器获取应变时程数据,处理成应力时程数据后,结合雨流计数法技术,得到"日应力谱"和"标准日应力谱"。利用标准日应力谱数据和相关疲劳规范,研究江阴长江大桥钢箱梁的疲劳寿命等问题。实桥实测数据分析表明,日应力谱和标准日应力谱分布具有相似规律。应变传感器记录的数据量很大,计算机常常由于硬件限制无法对长时间段的数据进行处理。研究表明,在计算实桥钢桥面板构造细节疲劳寿命时,利用"标准日应力谱"方法可较好地解决此问题。

Based on the measured strain, fatigue life prediction of details of orthotropic steel panel structure of Jiangyin Yangtze River Bridge is studied. Monitoring data of strain-time are obtained from the strain transduc- er disposed on the bridge. After the stress-time data are transferred to strain-time data, the day stress spectrum and standard day stress spectrum are obtained through the rain flow count method. Based on the data of the stan- dard day stress spectrum and corresponding criterions about fatigue, the fatigue life of steel box girder of Jiangyin Yangtze River Bridge is studied. The analysis on practically measured data indicates that the day stress spectrum and the standard day stress spectrum have some similar rules. And the data recorded by the strain sensors are nu- merous, therefore the computer can＇t deal with the data of a long period because of the limitation of hardware. The research results show that the method called the standard day stress spectrum can be used to estimate the fa- tigue life of the details of orthotropic steel bridge deck perfectly.