锈蚀钢筋混凝土框架结构的抗震韧性评估  

Evaluation of seismic resilience of corroded reinforced concrete frame structure

作　　者：邓鹏[1,2] 周锦鹏 黄频 DENG Peng;ZHOU Jinpeng;HUANG Pin(College of Civil Engineering,Hunan University,Changsha 410082,China;Key Laboratory of Building Safety and Energy Efficiency of the Ministry of Education,Hunan University,Changsha 410082,China)

机构地区：[1]湖南大学土木工程学院,湖南长沙410082 [2]湖南大学建筑安全与节能教育部重点实验室,湖南长沙410082

出　　处：《地震工程与工程振动》2023年第3期23-34,共12页Earthquake Engineering and Engineering Dynamics

基　　金：国家自然科学基金青年项目(51908205);国家自然科学基金重大项目(52090082);江西省自然科学基金项目(S2020QNJJB1234)。

摘　　要：随着时间的增长,暴露于环境中的钢筋混凝土结构会不断地发生混凝土劣化和钢筋锈蚀,一旦发生地震等灾害,将会给结构带来较大损伤。采用基于纤维梁单元的时变锈蚀损伤模型,综合考虑了钢筋混凝土的大部分潜在锈蚀损伤模式,包括钢筋截面损失和钢筋压缩屈曲效应的劣化、保护层混凝土和核心混凝土的退化、以及应变渗透效应劣化。在此基础上,对锈蚀钢筋混凝土框架结构的抗震韧性进行了评估。建立了该框架在未锈蚀状态和3种不同锈蚀程度下的OpenSees有限元模型,采用非线性静力分析,考虑腐蚀情况下结构的震前系统功能损失。并通过非线性时程分析获得地震易损性曲线,计算震后由钢筋混凝土结构损坏和相关停工时间引起的直接和间接损失。考虑了线性、三角和负指数等3种恢复函数,并根据结构的损坏程度确定了震后修复时间,计算了结构在不同地震强度和锈蚀程度下的抗震韧性。结果表明,地震强度小于0.2 g时,抗震韧性基本保持不变,地震强度超过0.2 g时,结构抗震韧性曲线随着地震强度增加呈现明显的下降趋势,当地震强度达到0.8 g时,15%锈蚀率的结构抗震韧性降低到0.51;锈蚀率低于10%时,结构抗震韧性随着锈蚀程度增大而减小,但当锈蚀程度大于10%后,结构随着锈蚀率的增加,抗震韧性曲线基本保持重合。Reinforced concrete(RC)structures exposed to the environment will continue to undergo concrete degradation and steel corrosion over time.Once disasters such as earthquakes occur,they will cause great damage to the structure.In this study,a time-variant corrosion damage model based on fiber beam elements is utilized to comprehensively consider the potential corrosion damage modes of RC frame structures,including losses of the reinforcement section and the compression buckling effect deterioration of the reinforcements,the degradation of the protective layer concrete and the core concrete,and the deterioration of the strain penetration effect.On this basis,the seismic resilience of a corroded RC frame structure was evaluated.Finite element model of the frame in the uncorroded state and three different levels of corrosion was established via OpenSees.Nonlinear static analysis was conducted to consider the functional loss of the structure because of corrosion.Then,the seismic fragility curves were obtained through nonlinear time history analysis.Based on fragility curves,the direct and indirect losses caused by the damage of the corroded RC frame structure and the related downtime after earthquakes were calculated.Three kinds of recovery functions including linear,triangular and negative exponent function are considered,the post-earthquake repair time was determined according to the damage degree of the structure.After that,the seismic resilience of the structure under different earthquake intensities and corrosion levels was calculated.The results show that when the seismic intensity is less than 0.2 g,the seismic resilience remains basically unchanged,but after the seismic intensity exceeds 0.2 g,the seismic resilience curve of the structure shows a significant downward trend with the increase of earthquake intensity,when the seismic intensity reaches 0.8 g,the seismic resilience of the structure with 15%corrosion rate is reduced to 0.51;when the corrosion rate is lower than 10%,the seismic resilience of the struct

关 键 词：时变锈蚀模型 锈蚀钢筋混凝土框架 抗震韧性 地震易损性 

分 类 号：TU375.4[建筑科学—结构工程]