摘要
沪苏通长江公铁大桥主航道桥为主跨1092 m的公铁两用钢桁梁斜拉桥,结合该桥结构受力和美学效果,对桥塔结构进行比选,确定桥塔采用330 m高的C60高强高性能混凝土钻石形塔,索塔锚固区采用钢锚梁锚固。桥塔塔柱与横梁采用C60高强高性能混凝土以减小桥塔截面尺寸和自重;采用以60 d强度作为混凝土配合比设计、强度评定依据,在关键区段设置防裂钢板网和冷却水管,优化配合比设计以及改进混凝土降粘、抗裂技术等措施,提高桥塔混凝土抗裂性和耐久性;采用三索面整体式钢锚梁索塔锚固结构改善索塔锚固区混凝土受力状态,提高索塔锚固区施工效率;通过在桥塔设置从桥面至塔顶的可检、可维、可达通道,为超高桥塔维养提供便利。有限元计算结果表明桥塔各项受力指标均满足规范要求。
The main navigational channel bridge of Shanghai-Suzhou-Nantong Changjiang River Bridge is a bi-purpose steel truss girder cable-stayed bridge with a main span of 1092 m.The bridge features its 330 m-high diamond-shaped pylons of C60 high-strength and high-performance concrete,which is considered balancing the load bearing behavior and aesthetic effect of the structure.The stay cables are anchored to pylons via steel anchor beams.The pylon columns and crossbeams are all made of C60 high-strength and high-performance concrete to minimize the cross-section dimension and selfweight of the pylons.The mix proportion and strength of the concrete was modified with the strength of the concrete after 60-day curing.Measures were taken to improve the cracking resistance and durability of the pylon concrete,including installing anti-cracking steel mesh and water cooling pipes in the critical zones,optimizing the mix proportion and upgrading the viscosity reduction and anti-cracking measures.By arranging stay cables in three cable planes and making the steel anchor beams and the pylon an integral structure,the concrete in the cable-to-pylon anchorage zone was in rational stress state and the construction efficiency of the cable-to-pylon anchorage zone was improved.The deck-to-pylon top inspection access inside the pylon can facilitate the future maintenance of the high-rise pylon.The numerical simulation results demonstrate that all the indexes of the load bearing capacity of the pylon meet the code requirements.
作者
胡文军
梅新咏
张燕飞
戴慧敏
HU Wen-jun;MEI Xin-yong;ZHANG Yan-fei;DAI Hui-min(China Railway Major Bridge Reconnaissance&Design Institute Co.,Ltd.,Wuhan 430056,China)
出处
《世界桥梁》
北大核心
2022年第3期1-7,共7页
World Bridges
基金
中国铁路总公司科技研究开发计划项目(2013G001-A-2)。
关键词
公路铁路两用桥
斜拉桥
桥塔
索塔锚固结构
钢锚梁
混凝土耐久性
结构设计
rail-cum-road bridge
cable-stayed bridge
pylon
cable-to-pylon anchorage structure
steel anchor beam
concrete durability
structural design
