Data for UTC Region II Year 2 Ranade-Okumus Final Report

The seismic vulnerability assessment methods currently used by state DOTs typically rely on as-built conditions of bridges. However, due to environmental deterioration, the structural performance can degrade over time. This research demonstrates the application of a combined durability-fragility assessment framework, developed by the authors, for a group of bridges in the states of New York and Washington. Corrosion of steel reinforcement is the main deterioration mechanism considered for durability evaluation. The computational framework demonstrated in this research consists of three parts: corrosion modeling, seismic fragility analysis, and risk analysis. The results show that all bridges become more vulnerable to seismicity due to corrosion deterioration. For a group of bridges, the order of vulnerability can change over time due to corrosion which affects the fragility each bridge differently depending on its layout, geometry, reinforcement detail, cover thicknesses, axial load ratio, salt exposure, etc. These results can be used to update the vulnerability scores of bridges and prioritize maintenance activities.当前美国州级交通运输部门（Department of Transportation, DOT）所采用的桥梁地震易损性评估方法，通常以桥梁的竣工实际状态为基准。然而，受环境劣化影响，桥梁结构性能会随时间推移逐渐退化。本研究针对纽约州与华盛顿州的一批桥梁，展示了作者团队开发的耐久性-易损性联合评估框架的应用。本次耐久性评估以钢筋锈蚀作为核心劣化机制。本研究采用的计算框架包含三个模块：锈蚀建模、地震易损性分析与风险分析。研究结果表明，受锈蚀劣化作用，所有桥梁的地震易损性均有所提升。对于这批桥梁而言，锈蚀对各桥易损性的影响程度存在差异，具体取决于其结构布置、几何尺寸、钢筋构造细节、混凝土保护层厚度、轴压比以及盐蚀暴露程度等多项参数，因此桥梁的易损性排序会随时间发生变化。上述研究结果可用于更新桥梁的易损性评分，并为养护作业的优先级制定提供参考依据。