Abstract

Optimization of the duration of Structural Health Monitoring (SHM) campaigns is rarely performed. This article provides a utility-based solution to posteriorly determine: i) optimal monitoring durations and ii) the extension of the service life of the welds on a steel bridge deck. The approach is illustrated with a case study focusing on remaining fatigue life estimation of the welds on the orthotropic steel deck of the Great Belt Bridge, in Denmark. The identification of the optimal monitoring duration and the decision about extending the service life of the welds are modelled by maximizing the expected benefits and minimizing the structural risks. The results are a parametric analysis, mainly on the effect of the target probability, benefit, cost of failure, cost of rehabilitation, cost of monitoring and discount rate on the posterior utilities of monitoring strategies and the choice of service life considering the risk variability and the costs and benefits models. The results show that the decision on short-term monitoring, i.e., 1 week every six months, is overall the most valued SHM strategy. In addition, it is found that the target probability is the most sensitive parameter affecting the optimal SHM durations and service life extension of the welds.

摘要

很少执行结构健康监测 (SHM) 活动的持续时间优化。本文提供了一种基于实用程序的解决方案，用于事后确定：i) 最佳监测持续时间和 ii) 延长钢桥面板上焊缝的使用寿命。该方法通过一个案例研究来说明，该案例研究侧重于丹麦大贝尔特大桥正交异性钢桥面板上焊缝的剩余疲劳寿命估计。通过最大化预期收益和最小化结构风险来模拟最佳监控持续时间的确定和延长焊缝使用寿命的决策。结果是参数分析，主要是对目标概率、收益、失败成本、修复成本、监控成本和贴现率对监控策略的后验效用以及考虑风险可变性和成本收益模型的使用寿命选择。结果表明，短期监测的决定，即每六个月1周，总体上是最有价值的SHM策略。此外，发现目标概率是影响焊缝的最佳 SHM 持续时间和使用寿命延长的最敏感参数。