预应力筋松弛变异对PC梁桥长期性能影响研究  

Study on Influence of Relaxation Variation of Prestressed Tendons on Long-Term Performance of PC Beam Bridge

作　　者：李金国 厉勇辉 LI Jin-guo;LI Yong-hui(Tongji University Architectural Design&Research InstituteCo.,Ltd.,Shanghai 200092,China;CCCC Second Navigation Engineering Bureau Co.,Ltd.,Wuhan 430040,China)

机构地区：[1]同济大学建筑设计研究院(集团)有限公司,上海200092 [2]中交第二航务工程局有限公司,湖北武汉430040

出　　处：《中国市政工程》2021年第6期98-101,106,131,132,共7页China Municipal Engineering

摘　　要：PC梁桥开裂和下挠与预应力筋长期预应力损失过大密切相关。针对环境温度和预应力不均匀性对预应力筋松弛和结构挠度的影响进行研究,提出一种考虑温度和预应力不均性的松弛损失计算公式。研究表明:高温作用会加快预应力松弛速率;预应力分布不均匀也会增加预应力损失。综合考虑这2个不利因素对PC梁桥长期挠度和结构应力影响是较大的。The cracking&down deflection of PC beam bridge are closely related to the excessive long-term prestress loss of prestressed reinforcement.The effects of ambient temperature&prestress heterogeneity on the relaxation of prestressed reinforcement&structural deflection are studied,and a calculation formula of relaxation loss considering temperature&prestress heterogeneity is proposed.The results show that high temperature will accelerate the relaxation rate of prestress;uneven distribution of prestress will also increase prestress loss.Comprehensive consideration of these two adverse factors has a great impact on the long-term deflection&structural stress of PC beam bridge.

关 键 词：PC桥梁 预应力筋松弛 环境温度 混凝土开裂 跨中下挠 

分 类 号：U448.21[建筑科学—桥梁与隧道工程]