The study presented in this paper describes the coupled influence of corrosion and cross-sectional shape on failure mechanism of reinforced concrete (RC) bridge piers subject to static and dynamic earthquake loading. To this end, two RC columns varied in cross-sectional shape and corrosion degree are considered. An advanced nonlinear finite element model, which accounts for the impact of corrosion on inelastic buckling and low-cycle fatigue degradation of reinforcing bars is employed. The proposed numerical models are then subjected to a series of monotonic pushover and incremental dynamic analyses. Using the analyses results, the failure mechanisms of the columns are compared at both material and component levels. Furthermore, using an existing model in the literature for uncorroded columns, a dimensionless corrosion dependent local damage index is developed to assess the seismic performance of the examined corroded RC columns. The proposed new damage index is validated against the nonlinear analyses results. It is concluded that the combined influence of corrosion damage and cross-sectional shape result in multiple failure mechanisms in corroded RC columns.

中文翻译：

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地震作用下钢筋混凝土桥墩断面形状和腐蚀破坏对破坏机理影响的数值研究

本文的研究描述了腐蚀和横截面形状对钢筋混凝土桥墩在静，动态地震荷载作用下的破坏机理的耦合影响。为此，考虑了两个截面形状和腐蚀程度不同的RC柱。采用高级非线性有限元模型，该模型考虑了腐蚀对钢筋非弹性屈曲和低周疲劳退化的影响。然后，对提出的数值模型进行一系列的单调推升和增量动力学分析。使用分析结果，可以在材料和组件级别比较圆柱的破坏机理。此外，使用文献中针对未腐蚀柱子的现有模型，建立了无因次腐蚀相关的局部破坏指数，以评估所检查的锈蚀RC柱的抗震性能。针对非线性分析结果验证了所提出的新损伤指数。结论是腐蚀损坏和横截面形状的综合影响导致腐蚀的RC柱出现多种破坏机理。