摘要
钢筋锈蚀是影响钢筋混凝土结构耐久性的一个重要因素,会引起结构的自振周期延长、地震需求变化及抗震能力衰减,使得锈蚀钢筋混凝土结构的地震易损性分析不同于未锈蚀钢筋混凝土结构。以一栋按我国规范设计的RC框架结构为研究对象,分别建立了未锈蚀和锈蚀结构的非线性有限元模型并进行了模型验证。分别采用云图法和条带法计算得到了钢筋混凝土结构在未锈蚀和锈蚀两种工况下的地震易损性曲线和函数参数,对锈蚀钢筋混凝土结构地震易损性分析的特殊性及其对地震易损性分析结果的影响进行了分析。分析结果表明:不考虑钢筋锈蚀引起的结构自振周期延长会错误估计锈蚀钢筋混凝土结构的地震易损性水平。采用云图法分析锈蚀钢筋混凝土结构的地震易损性会出现锈蚀结构的极限状态失效概率低于未锈蚀结构的情况。而条带法比云图法可以更好地反映钢筋锈蚀对钢筋混凝土结构地震易损性的影响。忽略钢筋锈蚀引起的结构抗震能力衰减会低估锈蚀钢筋混凝土结构地震易损性水平,建议在锈蚀钢筋混凝土结构地震易损性分析中采用基于Pushover的极限状态定义方法。
Reinforcement corrosion is an important factor that affects the durability of reinforced concrete(RC) structures. It can lead to elongation of structural natural period, change of structural demand, and deterioration of seismic capacity. This makes the seismic fragility analysis results for the corroded RC structures different from those for the uncorroded RC structures. An RC frame structure designed according to the existing code was taken as a study case. Nonlinear finite element models of uncorroded and corroded RC frame structures were developed and validated. Seismic fragility curves and the corresponding parameters of the case study building under the uncorroded and corroded conditions were obtained by both the cloud method and the stripe method. The special characteristics of the seismic fragility analysis method for the corroded RC structures were analyzed and their effects on the corresponding seismic fragility results were examined. The results show that the seismic fragility of the corroded RC structure cannot be estimated correctly without considering the elongation of structural period due to reinforcement corrosion. The seismic fragility analysis using the cloud method probably results in a lower failure probability exceeding a specific limit state for the corroded structure than that for the uncorroded counterpart. Therefore, the stripe method can better reflect the effect of reinforcement corrosion on the seismic fragility of RC structures than the cloud method. Ignoring the deterioration of structural seismic capacity will underestimate the results of seismic fragility of corroded RC structures. The Pushover-based limit state definition method is recommended to be used in the seismic fragility analysis of corroded RC structures.
作者
代旷宇
于晓辉
李雨适
吕大刚
DAI Kuangyu;YU Xiaohui;LI Yushi;LÜDagang(School of Civil Engineering,Zhengzhou University,Zhengzhou 450001,China;College of Civil Engineering and Architecture,Guilin University of Technology,Guilin 541004,China;School of Civil Engineering,Harbin Institute of Technology,Harbin 150090,China;China State Construction Engineering Corporation Limited,Egypt Branch,New Cairo 11924,Egypt)
出处
《建筑结构学报》
EI
CAS
CSCD
北大核心
2022年第8期20-31,共12页
Journal of Building Structures
基金
国家自然科学基金项目(51778198,52078176)
黑龙江省自然科学基金资助项目(YQ2020E023)。
