基于伽马过程的锈蚀钢筋混凝土桥梁检测维护策略优化

Optimization inspection and maintenance strategy for corrosive reinforced concrete girder bridges based on Gamma process

针对考虑钢筋锈蚀的钢筋混凝土桥梁结构,将钢筋局部锈蚀深度作为表征结构使用性能的退化指标,采用Gamma过程模拟其发展过程的不确定性;给出考虑钢筋锈蚀检测概率和维护措施的结构使用寿命预测模型和基于决策维护树模型的检测维护成本计算模型;以最大化桥梁经检测维护后的使用寿命期望和最小化检测维护成本为优化目标函数,提出基于Gamma过程和遗传算法的锈蚀钢筋混凝土桥梁结构检测维护策略优化分析方法。分析广西铁山港大桥钢筋混凝土30 m跨主梁,得到其检测维护策略的Pareto优化解集。研究结果表明:Pareto优化解集可提供在不同结构使用寿命期望和检测维护成本预算下收益最大的检测维护策略,为业主或土木基础设施管理部门提供决策依据。

For the deterioration of reinforced concrete（RC） girder bridges due to reinforcement corrosion, the corrosion depth of reinforcement was used to characterize the performance deterioration of structure and the Gamma process（GP）,and the uncertainties involved in the service of bridges were considered in simulating the propagation of corrosion depth.Considering the probability of detection（Po D） of reinforcement corrosion and maintenance, the service life prediction model was proposed. The inspection and maintenance cost model was also proposed based on the inspection and maintenance decision tree model. Based on maximization of the expected service life after inspection and maintenance and minimization of the expected inspection and maintenance cost, a method using the GP model and genetic algorithm（GA） to optimize the inspection and maintenance strategy was proposed to reduce the reinforcement corrosion of RC girder bridges. A 30 m span RC girder of the Guangxi Tieshan Port Bridge was calculated to get the Pareto solutions setof inspection and maintenance strategy. The results show that the Pareto solutions can provide the most profitable strategy under different service life expectations and economic budgets as well as decision reference for owners or civil infrastructure administrators in choosing inspection and maintenance strategy.