摘要
宜宾临港长江大桥主桥为(72.5+203+522+203+72.5)m双塔双索面钢箱梁斜拉桥,公铁平层,3号塔两侧钢箱梁采用双悬臂施工,4号塔边跨侧钢箱梁采用顶推施工,中跨侧钢箱梁采用单悬臂施工。基于无应力状态法控制理论,采用SCDS软件建立主桥有限元模型进行施工控制计算。主梁双悬臂拼装时利用边、中跨侧桥面吊机对称同步起吊待安装梁段并调整其空间位置,采用相邻梁段相对高程控制法进行精匹配;斜拉索索力以无应力索长张拉进行控制;中跨侧悬臂端临时辅助压重措施,完成钢箱梁跨越式过辅助墩和顶升式上过渡墩的施工。该施工控制技术确保了钢箱梁双悬臂施工和边跨2次上墩顺利完成,保证了塔梁临时竖向锚固束受力合理,桥梁结构受力和塔偏未超限,结构线形和索力偏差满足要求。
The main bridge of Lingang Changjiang River Bridge in Yibin is a two-pylon steel box girder cable-stayed bridge accommodating the road and rail traffic on the same deck.The bridge has a main span of 522 m,two side spans of 203 m and two end spans of 72.5 m,and the stay cables are fanned out in double cable planes.The steel box girders on the two sides of the north pylon(pylon No.3)were erected by a balanced cantilever method,the steel box girders in the side span besides the south pylon(pylon No.4)were erected by the incremental launching method,and the steel box girders in the central span were erected by the one-way cantilever method.Following the control principles of the stress-free-state method,the finite element model of the main bridge was established in SCDS software for construction control calculation.During the balanced cantilever assembly of the steel box girder,the derrick cranes in the side and central spans worked in parallel in hoisting and adjusting the spatial locations of girder segments.The relative elevations of two adjacent segments were controlled for precise matching.The stay cable forces were controlled via the stress-free-length tensioning.The cantilever tips in the central span were temporarily counterweighted to facilitate the maneuver of the steel box girder segments on the top of auxiliary piers and resting on the top of transition piers via jacking.The construction control techniques ensured the success of the two-way cantilever assembly of the steel box girder segments and two times of jacking the steel box girders onto the top of piers.The configuration of the temporary vertical prestressing tendons in the pylons and main girders is effective,the loads on the bridge structure and pylon displacement did not surpass the limits,and the structural alignment and stay cable force errors reached the required levels.
作者
刘虎虎
吴凯
严和仲
LIU Huhu;WU Kai;YAN Hezhong(China Railway Bridge&Tunnel Technology Co.,Ltd.,Nanjing 210061,China)
出处
《世界桥梁》
北大核心
2024年第1期65-71,共7页
World Bridges
关键词
斜拉桥
钢箱梁
双悬臂施工
无应力状态法
索长张拉
跨越式过辅助墩
顶升式上过渡墩
施工控制
cable-stayed bridge
steel box girder
balanced cantilever assembly
stress-free-state method
cable length tensioning
maneuver across auxiliary pier
jacking onto transition pier
construction control
