疲劳作用下CFRP加固混凝土梁抗弯可靠度分析  

Reliability analysis on flexural resistance of concrete beams strengthened with CFRP considered action of fatigue

作　　者：朱泽文 代力 毛琳 ZHU Zewen;DAI Li;MAO Lin(Jiangxi Transportation Research Institute Co.,Ltd.,Nanchang 330200,China;Key Laboratory of Bridge Structure of Jiangxi Province,Nanchang 330200,China;Research and Development Center on Technogies and Equipment of Long-span Bridge Construction Minsistry of Transport,Nanchang 330200,China)

机构地区：[1]江西省交通科学研究院有限公司,南昌330200 [2]江西省桥梁结构重点实验室,南昌330200 [3]长大桥梁建设技术及装备交通运输行业研发中心,南昌330200

出　　处：《建筑结构》2023年第6期143-149,共7页Building Structure

基　　金：江西省自然科学基金资助项目(20202BABL214043);江西省交通运输厅科技项目(2019Z0002、2021C0008、2022H0014、2022C0007)。

摘　　要：为了更好地评估单轨交通混凝土轨道梁加固后的服役寿命,建立了基于环境与疲劳荷载双重作用影响下的加固梁抗弯承载力功能函数时变模型。同时,基于JC法计算不同疲劳频次下混凝土梁加固前后的时变抗弯可靠度。结果表明:在疲劳与环境等因素作用下,早期混凝土梁的抗弯可靠度呈线性下降,而在后期降低速率进一步的增大,相比单一环境因素影响其可靠度下降更快。另外,混凝土梁的抗弯可靠度呈现出随年交变频率增加而逐渐降低的明显趋势。在运营基准期的52%后,混凝土梁应用侧面内嵌CFRP加固技术,能够继续运营基准期的34%。总的来看,采用侧面内嵌技术加固混凝土梁,可有效提供其服役寿命,服役早期加固效果更佳。In order to better evaluate the service life of monorail rail strengthened concrete beams,a time-varying model of the functional function of the flexural capacity of the strengthened beams based on the dual effects of environment and fatigue was established.At the same time,the time-varying flexural reliability of concrete beams before and after strengthening under different fatigue frequencies was calculated based on the JC method.The results show that the flexural reliability of concrete beams decreased linearly in the early stage with the service time,and the rate of decrease further increases in the later stage,under the combined action of fatigue load and environment.Compared with a single environmental factor,its reliability decreased faster.In addition,the flexural reliability of concrete beams show an obvious trend of gradually decreasing as the frequency of annual alternating loads increases.The concrete beams were reinforced with side near surface mounted(SNSM)technique after 52%of the service base period,and could continue to serve about 34%of the service base period.In general,the use of SNSM technique to strengthen the concrete beams can effectively provide its service life,and the effect of early reinforcement is better.

关 键 词：疲劳作用 环境作用 抗弯可靠度 混凝土梁 侧面内嵌技术 CFRP加固 

分 类 号：TU375.1[建筑科学—结构工程]