This study investigates the seismic life-cycle cost of aging highway bridges under chloride exposure when subjected to multiple main shock earthquake events along the design lifetime of the structure. While chloride induced corrosion manifests as a continuous deterioration process, earthquake occurrences are typically intermittent. Although relatively weak seismic events that induce none-to-minor bridge damage may not instigate immediate intervention and repair, resulting structural cracks may further accelerate the corrosion process. This study presents a novel Monte Carlo based methodology that explicitly considers potentially altered deterioration pattern between seismic shocks as well as uncertainty in earthquake occurrences, record-to-record variability, repair decisions and repair processes for seismic life-cycle cost computations. The proposed framework also eliminates the need for the often improbable assumption in past literature on seismic life-cycle cost assessment that necessitates structural rehabilitation to pre-hazard states regardless of the seismic damage level. Case-study application of the proposed framework is demonstrated on a single column integral bridge located in the marine splash zone in California, United States. Results from multiple main shock analysis of both non-deteriorating and aging case-study bridge reveals a significant contribution of cumulative damage from corrosion deterioration and shock sequences towards seismic loss and life-cycle cost assessment.

这项研究调查了在结构设计寿命中遭受多次主震地震事件的氯暴露下老化公路桥梁的地震生命周期成本。尽管氯化物引起的腐蚀表现为连续的恶化过程，但地震的发生通常是间歇性的。尽管相对较弱的地震事件不会引起桥梁的轻微损坏，但可能不会立即进行干预和修复，但由此产生的结构裂缝可能会进一步加速腐蚀过程。这项研究提出了一种新颖的基于蒙特卡洛的方法，该方法明确考虑了地震冲击之间潜在改变的恶化模式以及地震发生中的不确定性，记录间差异，维修决策和维修过程，以计算地震生命周期成本。所提出的框架还消除了在过去关于地震生命周期成本评估的文献中通常不太可能的假设的需要，该假设使得无论地震破坏水平如何，都必须将结构恢复到危险前状态。拟议框架的案例研究应用在位于美国加利福尼亚海洋飞溅区的单列整体式桥梁上得到了证明。对未退化和老化的案例研究桥梁进行多次主冲击分析的结果表明，腐蚀恶化和冲击序列对累积损伤的重大贡献对地震损失和生命周期成本评估具有重要意义。