摘要
在大跨度预应力混凝土桥梁中,由于材料缺陷或施工工艺的不成熟导致竖向预应力损失,在腹板上产生斜裂缝。如何选择施加竖向预应力的材料和合理的锚固体系、确保预应力钢筋施工质量,成为工程设计中关注的焦点。为了在工程设计中选择合适的预应力筋和张拉工艺,确保有效的预应力,从构造、锚固体系、施工工艺和性能上,分析了工程中常用的精轧螺纹钢筋、预应力钢绞线、无粘结预应力钢棒三种不同的竖向预应力体系,并简述了其竖向预应力损失的关键因素,对比分析了各个体系的优异性,为工程设计提供参考。
Due to the loss of vertical prestress caused by material defects or immature construction technology,inclined cracks are produced on the web in the long-span prestressed concrete bridge.How to select the materials for the application of vertical prestress and reasonable anchorage system to ensure the construction quality of prestressed reinforcement has become the focus of engineering design.In order to facilitate the selection of appropriate prestressed reinforcement and tensioning process in engineering design and ensure effective prestress,three different vertical prestress systems commonly used in engineering,including finish rolled threaded reinforcement,prestressed steel strand and unbonded prestressed steel bar,are analyzed from the aspects of structure,anchorage system,construction technology and performance,the key factors of vertical prestress loss are briefly described,and the advantages of each system are compared and analyzed,so as to provide reference for engineering design.
作者
郑宏利
陈恒
Zheng Hongli;Chen Heng(China Railway 16th Bureau Group Road and Bridge Engineering Co.,Ltd.,Beijing 101500,China)
出处
《北方交通》
2021年第12期5-10,共6页
Northern Communications
基金
中铁十六局校企资助基金(07WTX-JSFW-2019-0001)。
关键词
大跨度预应力混凝土桥梁
箱梁腹板
精轧螺纹钢筋
预应力钢绞线
无粘结预应力钢棒
竖向预应力
Long-span prestressed concrete bridge
Box girder web
Finish rolled deformed bar
Prestressed steel strand
Unbonded prestressed steel bar
Vertical prestress
