摘要
为了研究碳化环境与重复列车荷载耦合作用下城市轨道交通U型梁的疲劳损伤演化规律以及腐蚀疲劳性能,提出一种考虑碳化锈蚀与疲劳耦合效应的城市轨道交通U型梁腐蚀疲劳寿命评估方法,研究混凝土保护层疲劳开裂对钢筋锈蚀的加速效应以及钢筋锈蚀对疲劳抗力的影响。针对某城市轨道交通高架线的30 m预应力混凝土U型梁,采用该方法评估该U型梁在设计工况下的疲劳损伤演化规律和腐蚀疲劳寿命,并分析不同列车通行频率和碳化环境对疲劳损伤演化及腐蚀疲劳寿命的影响。研究结果表明:在所设计的碳化环境和列车通行频率下,U型梁的腐蚀疲劳寿命为403 a,表明U型梁的腐蚀疲劳性能良好;碳化环境和列车通行频率对U型梁腐蚀疲劳寿命影响较大;与设计工况相比,极端碳化环境和极限列车通行频率分别导致U型梁的腐蚀疲劳寿命下降30.28%和31.27%,在两者共同作用下,腐蚀疲劳寿命下降45.41%。
To study the fatigue damage evolution law and corrosion-fatigue performance of urban rail transit U-typed beam under the coupled effect of carbonation environment and repeated train load,a corrosion-fatigue life assessment method of U-typed beam considering the coupled carbonation-induced corrosion and fatigue loads effect was proposed.In the proposed method,the acceleration effect of concrete cover fatigue cracking on reinforcement corrosion was considered,and the influence of reinforcement corrosion on fatigue resistance was taken into account.The proposed method was applied in the 30 m U-typed prestressed concrete beam in an urban rail transit viaduct.The fatigue damage evolution law and corrosion-fatigue life of the U-typed beam under design conditions were evaluated.The effects of train passing frequency and carbonation environment level on fatigue damage evolution and corrosion-fatigue life were analyzed.The results show that the corrosion-fatigue life of the U-typed beam is 403 years at the design carbonation environment level and train passing frequency,which suggests that the fatigue performance of the U-typed beam is good.Carbonation environment level and train passing frequency can strongly influence the corrosion-fatigue life of U-typed beam.Compared with the design condition,the extreme carbonation environment and the ultimate train passing frequency can reduce the corrosionfatigue life of the U-typed beam by 30.28% and 31.27%,respectively.The corrosion-fatigue life of the U-typed beam decreases by 45.41% under the combined action of these two conditions.
作者
崔晨星
宋力
陈桂香
余志武
CUI Chenxing;SONG Li;CHEN Guixiang;YU Zhiwu(School of Civil Engineering,Central South University,Changsha 410075,China;National Engineering Research Center of High-speed Railway Construction Technology,Central South University,Changsha 410075,China;School of Civil Engineering,Henan University of Technology,Zhengzhou 450001,China)
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2022年第2期747-755,共9页
Journal of Central South University:Science and Technology
基金
国家自然科学基金资助项目(51778631,52078492,U1934217)
朔黄铁路发展有限责任公司科研项目(SHGF-18-50)
中国中铁股份有限公司重大专项(2020-重大-2)。
关键词
城市轨道交通
U型梁
腐蚀疲劳寿命
碳化锈蚀
耦合作用
疲劳损伤演化
urban rail transit
U-typed beam
corrosion-fatigue life
carbonation induced-corrosion
coupled action
fatigue damage evolution
