摘要
延崇高速砖楼特大桥主桥采用(65+120+65) m上承式拱形变高钢桁组合连续梁,双幅分离,分别位于平面圆曲线、缓和曲线及直线段上,平面以直代曲、桥面超高及超高过渡变化使得钢结构和桥面系异常复杂,且钢桁梁杆件种类和数量繁多、空间结构复杂。主梁施工采用双幅共用塔吊+履带吊悬拼方案,经济适用性强,解决了山区施工条件受限难题;主墩处采用托架+倒T形立柱精调系统,确保平、纵面曲线连续钢桁梁悬拼起始节间安装精度,以及双悬臂架设安全性;杆件连接时利用标准冲钉控制杆件形位,通过控制安装拱度和桥面轴线实现高精度线形控制;采用Z形托架辅助边跨上墩,通过边跨压重、合龙口斜角对拉技术确保合龙段快速精确安装,完成结构体系转换;采用吊架法施工桥面悬臂现浇段混凝土,实现平面曲线线形和桥面超高过渡需求。
The main bridge of Zhuanlou Bridge carrying a section of the Yanqing-Chongli Expressway are deck-type haunched steel truss bridges,each with two identical three-span continuous structures of 65,120,and 65 m.The two expansion units are curved,each featuring a circular section,a transition section and a straight section,and in computation,the curves are approximated as straight lines.The deck superelevation and superelevation transition variation make the geometry of the steel truss and deck system quite complicated.The steel truss is a complex spatial structure comprising a large number of members of varying types.To accommodate the bridge site in the mountainous region and achieve the best economic performance,a hammerhead crane was employed for the installation of the twin superstructures of each bridge,and the bridge components were cantilever-assembled using a crawler crane.The main piers were constructed by a combined utilization of corbels and inversed T-post fine-tuning system,to ensure the installation accuracy of the starter panel of the steel truss in the plan and profile geometry,and the balanced-cantilever installation safety as well.During the connection of the members,standard drift pins were used to aid hole shaping in members,by controlling the installation camber and deck axis to realize high-precision geometry control.The truss in the side spans were lowered onto the piers via the corbels.The side spans were counterweighted,and the diagonal-tensioning technique was used to ensure the rapid and accurate installation of the key truss panel and to achieve the system transformation.The lifting frames were used to facilitate the pouring of the concrete in the bridge cantilevers,and guarantee the required plan curve and deck superelevation transition.
作者
朱云萍
胡杰
涂满明
ZHU Yunping;HU Jie;TU Manming(China Railway Major Bridge Engineering Group Co.,Ltd.,Wuhan 430050,China)
出处
《世界桥梁》
北大核心
2025年第3期26-32,共7页
World Bridges
关键词
钢桁组合连续梁
悬臂拼装
托架
精调系统
线形控制
体系转换
吊架法
施工技术
steel truss composite continuous girder
cantilever assembly
corbel
fine-tuning system
geometry control
system transformation
lifting frame
construction technique
