预应力现浇连续箱梁桥跨结构预应力损失的影响因素分析  

Analysis of Influencing Factors of Prestressing Loss of Span Structure of Prestressed Cast-in-situ Continuous Box Girder Bridge

作　　者：邢晓东 牟雨龙 张康荣 郭迎旗 Xing Xiaodong;Mu Yulong;Zhang Kangrong;Guo Yingqi(Powerchina Roadbridge Group Co.,Ltd.,Beijing 100048,China)

机构地区：[1]中电建路桥集团有限公司,北京100048

出　　处：《科学技术创新》2022年第25期90-93,共4页Scientific and Technological Innovation

摘　　要：从台城河特大桥施工实例出发,针对现浇预应力连续箱梁的预应力损失问题展开探究。对预应力控制理论的计算原理进行深入探讨,总结出孔道压浆摩阻是影响预应力现浇箱梁结构预应力损失的首要因素;结合摩阻分析推导出预应力影响因素,并通过公式分别证明了预应力钢绞线会产生应力松弛,结构混凝土会有收缩徐变的特性,这二者共同构成结构混凝土长期预应力损失的主要影响因素。最后提出,通过加密配置预应力筋或各种复合加筋材料可延缓预应力桥梁结构的这类特性,可使得预应力损失减到最小,从而延长桥跨结构的服役时间。Starting from the construction example of Taichenghe Bridge,the problem of prestress loss of cast-in-place prestressed continuous box girder is explored.The calculation principle of the prestress control theory is deeply discussed,and it is concluded that the grouting friction is the primary factor affecting the prestress loss of the prestressed cast-in-situ box girder structure;the prestress influencing factors are deduced based on the friction resistance analysis,and the formulas are used to separate the It is proved that the prestressed steel strand will produce stress relaxation,and the structural concrete will have the characteristics of shrinkage and creep,which together constitute the main influencing factors of the long-term prestress loss of structural concrete.Finally,it is pointed out that such characteristics of prestressed bridge structures can be delayed by densely configuring prestressed tendons or various composite reinforcement materials,which can minimize the loss of prestressing and thus increase the service time of bridge span structures.

关 键 词：预应力连续箱梁 预应力损失 压浆摩阻 应力松弛 收缩徐变 

分 类 号：U448.215[建筑科学—桥梁与隧道工程] U448.35[交通运输工程—道路与铁道工程]