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首先介绍了润扬大桥悬索桥的健康监测系统。然后对健康监测系统所监测的应力时程进行处理,得到钢箱梁疲劳应力谱,分析了应力谱的特点。利用健康监测数据评估钢箱梁的疲劳寿命时,以单天或几天平均的疲劳应力谱进行疲劳寿命评估使得疲劳寿命过大或过小。考虑到交通流量的随机性,研究了日累计损伤度分布规律,提出了考虑交通流量随机性的钢箱梁疲劳破坏失效概率及可靠度评估方法。该方法能够更精确地进行钢箱梁失效概率及可靠度评估,可为大桥的日常维护和耐久性评估提供参考依据。
Firstly, the health monitoring system of Runyang Bridge suspension bridge is introduced. Then the stress time history monitored by the health monitoring system is processed, the fatigue stress spectrum of the steel box girder is obtained, and the characteristics of the stress spectrum are analyzed. When health monitoring data is used to evaluate the fatigue life of steel box girders, the fatigue life assessment based on fatigue stress spectra averaging one or a few days makes the fatigue life too large or too small. Considering the randomness of traffic flow, the distribution rule of daily cumulative damage degree is studied and the failure probability and reliability evaluation method of steel box girder considering the randomness of traffic flow are proposed. The proposed method can evaluate the failure probability and reliability of steel box girder more accurately and provide a reference for the routine maintenance and durability evaluation of the bridge.