Abstract redundancy of reinforced concrete (RC) structures, which is generally used to describe the progressive collapse performance, has gained worldwide interests since it is greatly related with the vertical bearing capacity of the structure when subjected to loss of structural components. Especially, in some aggressive environments, the redundancy of RC structures may be an even severer problem since corrosion of reinforcement will cause deterioration of the material properties, thus the progressive collapse potential may get increased. In this paper, we present a quantitative study of the influence of the corrosion effect on the redundancy of the structures. The reliability-based redundancy quantification framework is firstly introduced, in which the static pushdown method is used to represent the progressive collapse behavior of the structure and the probability density evolution method (PDEM) is employed to calculate the reliability index. Then an efficient deterministic finite element modeling strategy is presented in detail, where the fiber element is adopted to model the beam/column components and the macro-level joint model is used to model the bond-slip behavior at the beam-to-column connections. Thirdly, a probabilistic corrosion model is adopted to represent the corrosion effect, which accounts for the variability in both time and space domains. Then the deterioration of concrete properties, reinforcement properties, as well as the bond behavior between these two materials that are induced by the corrosion effect is incorporated into the finite element model. Finally, a case study of RC building subjected to progressive collapse is designed to demonstrate the capacity of the framework and to investigate the time-dependent reliability and redundancy of the structure. Meanwhile, the influences of different corrosion modeling assumptions are also studied.

中文翻译：

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考虑腐蚀效应的老化钢筋混凝土结构抗连续倒塌的基于时间依赖可靠性的冗余评估

摘要 钢筋混凝土（RC）结构的冗余性通常用于描述连续倒塌性能，由于它与结构在遭受结构构件损失时的垂直承载能力密切相关，因此受到了全世界的关注。特别是在一些侵蚀性环境中，钢筋混凝土结构的冗余可能是一个更严重的问题，因为钢筋腐蚀会导致材料性能恶化，从而增加连续倒塌的可能性。在本文中，我们对腐蚀效应对结构冗余的影响进行了定量研究。首先介绍了基于可靠性的冗余量化框架，其中采用静力下推法表示结构的连续倒塌行为，采用概率密度演化法（PDEM）计算可靠度指标。然后详细介绍了一种有效的确定性有限元建模策略，其中采用纤维单元对梁/柱组件进行建模，并使用宏观节点模型对梁柱连接处的粘结滑移行为进行建模。 . 第三，采用概率腐蚀模型来表示腐蚀效应，它解释了时间和空间域的可变性。然后将腐蚀效应引起的混凝土性能、钢筋性能以及这两种材料之间的结合行为的恶化纳入有限元模型。最后，RC 建筑遭受连续倒塌的案例研究旨在证明框架的能力并研究结构的时间依赖性可靠性和冗余性。同时，还研究了不同腐蚀建模假设的影响。