基于动态可靠度和经济优化相结合的服役桥梁维修加固风险决策

服役桥梁的维修加固需要综合考虑安全和经济的问题,基于服役桥梁的动态可靠度,以后续服役期内收益期望值最大或损失期望值最小为目标函数,对服役桥梁的维修加固决策进行了探讨,利用实际检测数据修正抗力模型,对一座服役期为35年的钢筋混凝土梁桥动态可靠度进行了计算,同时,比较分析了汽车荷载等级的提高和采用不同维护加固措施对后续服役期内动态可靠度的影响。该方法结合工程实际,把失效损失与失效风险相结合,对桥梁结构的维修加固决策有一定的指导作用。

RISK-RANKING DECISION OF REPAIR AND STRENGTHENING OF EXISTING BRIDGES BASED ON TIME-DEPENDENT RELIABILITY AND ECONOMICAL OPTIMIZATION

The issue of safety and economy should be considered in the repairing and strengthening of existing bridges. The strategy on repair and strengthening of existing bridges based on time-dependent reliability has been analyzed with the maximum expected benefit or the minimum expected cost of failure consequence as the objective function. A practical application of risk-ranking decision is illustrated herein based on updated inspection information with the bridge survival age 35. The effects of improvement of live load and difference of repair methods on time-dependent reliability of existing bridges are studied. The decision method can be used in real project, with the cost of failure consequence and the risk of failure considered. It has certain reference value in the repair and strengthening decision of existing bridges.