重载与氯盐环境下混凝土桥梁疲劳损伤当量分析研究  

ANALYSIS OF EQUIVALENT FATIGUE DAMAGE FOR CONCRETE BRIDGE UNDER OVERLOADING AND CHLORIDE ENVIRONMENT

作　　者：徐方圆 张征文[1] XU Fangyuan;ZHANG Zhengwen(Zhejiang Institute of Communications,Hangzhou 311112,China)

机构地区：[1]浙江交通职业技术学院,杭州311112

出　　处：《工业建筑》2019年第3期174-179,共6页Industrial Construction

基　　金：浙江省自然科学基金(LY18E080002);浙江省公路管理局科技计划项目(201708);浙江省教育厅一般科研项目(Y201839596)

摘　　要：国、省道公路混凝土桥梁因劣化环境及车辆超载导致的结构损伤问题尤为突出,需建立较为实用的混凝土桥梁疲劳损伤分析方法,并能与治超管理相协调。首先提出混凝土桥梁疲劳损伤当量分析方法,以一座预应力混凝土连续箱梁桥为例,研究超载作用下的桥梁疲劳损伤发展规律;在此基础上,考虑氯盐环境下性能退化,以钢筋脱钝时间和保护层胀裂时间作为界限时间点,分析各时间阶段内重载作用下的预应力混凝土桥梁疲劳损伤发展规律。结果显示:车辆荷载与疲劳损伤之间存在着非线性指数发展规律,考虑氯盐与重载作用下的预应力混凝土桥梁疲劳损伤当量参数b_f值的三阶段变化反映了预应力筋锈蚀对结构性能的影响。The problem of structural damage caused by vehicle overloading and chloride environment has been particularly acute in concrete bridges of national and provincial roads. A convenient and accurate fatigue damage analysis method for concrete bridge is expected to be well coordinated with overload management. In the paper, an equivalent fatigue damage analysis method was proposed. A prestressed concrete box-girder bridge was applied to study the evolution of equivalent fatigue damage. Moreover, the performance degradation due to chloride environment was also taken into consideration. Under the combined action of overloading and chloride environment, taking the depassivation time of steel bar and expasion and cracking time of protective layer as the time points, the fatigue damage evolutions of prestressed concrete bridge in each stage were analyzed. The results showed that there was exponential growth between the vehicle load and the fatigue damage. Under chloride and overloading environment, the three stages of the parameter bf in the equivalent fatigue damage function reflects the influence of prestressed steel corrosion on the structural performance.

关 键 词：重载 氯盐环境 钢筋锈蚀 疲劳损伤 当量分析 

分 类 号：U441[建筑科学—桥梁与隧道工程]