大跨钢桁结合梁悬索桥现浇桥面板拉应力优化研究  

Tensile Stress Modification for Cast-in-Situ Deck Slabs of Long-Span Steel Truss Girder Suspension Bridge

作　　者：唐茂林[1] 李超 陶齐宇 王昆 TANG Mao-Lin;LI Chao;TAO Qi-yu;WANG Kun(School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;Sichuan Transportation Construction Group Co.,Ltd.,Chengdu 610041,China;Sichuan Highway Planning,Survey,Design and Research Institute Ltd.,Chengdu 610041,China)

机构地区：[1]西南交通大学土木工程学院,四川成都610031 [2]四川省交通建设集团有限责任公司,四川成都610041 [3]四川省公路规划勘察设计研究院有限公司,四川成都610041

出　　处：《桥梁建设》2023年第3期127-134,共8页Bridge Construction

基　　金：国家自然科学基金项目(51478391)。

摘　　要：为改善大跨钢桁结合梁悬索桥现浇桥面板的拉应力,解决现浇桥面板在负弯矩区易开裂的问题,以四川卡哈洛金沙江大桥(主跨1030 m的钢桁结合梁悬索桥)为背景,对现浇桥面板拉应力优化进行研究。采用有限元软件BNLAS建立桥梁三维模型,通过施工阶段分析揭示现浇桥面板拉应力产生的机理,研究浇筑长度、桥面板浇筑顺序、工作面数量3个因素对浇筑后桥面板与钢桁梁应力的影响。结果表明:减小现浇桥面板浇筑长度可有效降低其浇筑后最大拉应力,但当浇筑长度较小时,继续减小浇筑长度对降低桥面板拉应力的效果会减弱;不同桥面板浇筑顺序对桥面板浇筑后的应力有较大影响,将工作面在主跨范围内均匀布置可以得到较优的应力;增加工作面数量可进一步降低桥面板的拉应力,降低浇筑过程中钢桁梁杆件最大应力,工作面数量从2个增加到4个,对降低现浇桥面板浇筑后最大拉应力效果较好。建议该桥现浇桥面板施工采用浇筑长度84 m、工作面数量4个、工作面沿主跨均匀布置的方案。The study in this paper focuses on ways to improve the tensile stresses in the cast-in-situ deck slabs of long-span steel truss girder suspension bridge as well as ways to enhance the anti-cracking capability of the deck slabs in the hogging moment zones.The Kahaluo Jinshajiang River Bridge that is a suspension bridge with a main span of 1030 m is applied as a case to study the tensile stress modification for the cast-in-situ deck slabs.A 3D model of the bridge was built up in BNLAS to simulate the construction process of the bridge,aiming to reveal the generation mechanism of tensile stresses in cast-in-situ deck slabs and investigate the influence of casting length,casting sequence of deck slabs and number of operation platforms on the stresses in the deck slabs and steel trusses after concrete casting.It is shown that reducing the one-round casting length can effectively reduce the maximum tensile stress in the completed deck slabs,casting sequence also exerts great influence on the stresses in the completed deck slab,when the operation platforms are uniformly arranged within the scope of main span,the tensile stresses will be in the optimal condition.Adding extra operation platforms can further reduce the tensile stresses in the deck slabs,scale down the maximum tensile stresses in the members of steel trusses during casting.When the operation platforms are increased from two to four,the maximum tensile stresses in the completed deck slabs are notably decreased.A casting length of 84 m and four operation platforms are recommended,additionally the operation platforms should be uniformly arranged along the main span.

关 键 词：悬索桥 钢桁结合梁 现浇桥面板 浇筑长度 浇筑顺序 工作面数量 桥面板应力 有限元法 

分 类 号：U448.25[建筑科学—桥梁与隧道工程] U445[交通运输工程—道路与铁道工程]