潍莱铁路跨青荣特大桥全焊接免涂装耐候钢钢桁梁设计  

Design of All-Welded Coating-Free Weathering Steel Truss Girder Bridge of Weifang-Laixi Railway Crossing Qingdao-Rongcheng Intercity Railway

作　　者：孙宗磊 张上 SUN Zong-lei;ZHANG Shang(School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;China Railway Economic and Planning Research Institute,Beijing 100038,China;China Railway Design Corporation,Tianjin 300308,China)

机构地区：[1]西南交通大学土木工程学院,四川成都610031 [2]中国铁路经济规划研究院,北京100038 [3]中国铁路设计集团有限公司,天津300308

出　　处：《桥梁建设》2021年第1期109-114,共6页Bridge Construction

基　　金：中国铁路设计集团有限公司科技开发课题(721772)。

摘　　要：潍莱铁路跨青荣特大桥采用(120+82)m连续钢桁梁+框架墩结构。该桥钢桁梁采用变高度曲弦、带竖杆的三角桁,桁高13~25m,桥面采用正交异性板结构,密布横梁体系,不设小纵梁。钢桁梁采用全焊接免涂装耐候钢,主桁采用Q370qENH钢、联结系采用Q345qDNH钢,钢材耐大气腐蚀性指数I≥6.0。钢桁杆件间连接采用全焊接构造,采用单面焊双面成型的现场焊接工艺,焊缝背面设陶瓷衬垫;考虑焊接空间,在杆件横隔板处开设过人洞。钢桁梁采用大悬臂横移方案施工,中支点框架墩兼做横移时的滑道梁,82m边跨为悬臂状横移跨越青荣城际,此方案既节省了投资,又减少了对既有线的影响。The part of Weifang-Laixi Railway crossing the Qingdao-Rongcheng Intercity Railway is designed as a continuous steel truss girder bridge with two spans of 120and 82m,supported by portal-framed piers.The superstructure consists of triangular trusses with curved chords of varying depth and vertical rods,measuring 13-25 mhigh.The deck is composed of orthotropic steel plates supported on densely-spaced cross beams,and no stringers are used.The steel trusses are formed of all-welded coating-free weathering steel,Q370qENH steel for main trusses and Q345qDNH steel for lateral bracings,which have got the atmospheric corrosion resistance index I equal to or more than 6.0.All the members of the steel trusses were welded together in situ,using the single-sided welding and double-sided forming technique,and ceramic weld backings were employed.To ensure the space for welding,manholes are opened on the diaphragms.The steel truss girders were first assembled to be large cantilevers,and then transversely moved,and the central portal-framed pier was spared to support sliding rails.The steel trusses in the 82 m-long side span were first assembled to form a cantilever and then transversely moved to cross the Qingdao-Rongcheng Intercity Railway.The solution can not only cut down construction costs,but also bring less disruption to the existing railway.

关 键 词：铁路桥 钢桁梁 耐候钢 全焊接 免涂装 大悬臂横移施工 结构设计 

分 类 号：U448.13[建筑科学—桥梁与隧道工程] U442.5[交通运输工程—道路与铁道工程]