摘要
湖北燕矶长江大桥为主跨1860 m不同垂度四主缆单跨双层钢桁梁悬索桥,猫道创新性采用双层承重索体系+等宽非对称断面+下层承重索穿塔的方案。为兼顾后续主缆索股牵引,上游侧单幅猫道采用往复对拉牵引循环系统施工。先导索为ϕ20 mm钢丝绳,利用下游侧已形成的牵引系统采用吊绳法空中牵引并横移就位。猫道下层承重索采用托架法进行架设,其中托架承重索为2根ϕ44 mm大直径钢丝绳,创新采用前端牵引+后端反拉架设工艺。猫道下层承重索前端绳头设置转换接头以便快速穿塔,牵引到位后现场灌铸锚头。中跨猫道面层前端带横向天桥下滑,并设置滚轮以减少对钢丝绳的磨损。根据等宽非对称猫道的特点,猫道改吊至主缆时,需在2幅猫道内侧配重以防猫道倾斜。
The Yanji Changjiang River Bridge in Hubei Province is a suspension bridge with a single suspended main span of 1860 m,featuring the trussed superstructure accommodating two levels of decks and the four main cables with different sag.The catwalks were tailored for the bridge,to address the structural characteristics of the four-main-cable configuration,which comprised two levels of load-bearing cables(the load bearing cables on the lower level are threaded through the tower columns)and are of constant-width,asymmetric cross-section.To facilitate the towing of main cable strands,the upstream catwalk was erected by a cycled to-and-from towing system.The pilot cable was a 20 mm-diameter steel rope,which was towed and transversely moved into position by the suspension rope method with the assistance of the existing downstream towing system.The load-bearing cables on the lower level of the catwalk were erected by the"bracket method",where two,44 mm-diameter steel ropes were used as the load-bearing cables for the brackets,towed at the front end and pulled at the rear end to keep the structure in equilibrium.The front head of each lower-level load-bearing cable was fitted with an adapter to ease the installation of the cable,after towed into position,the anchor head was grouted.The floor system of the central-span catwalk was lowered with transverse gangways attached,incorporating rollers to minimize abrasion on steel ropes.It is necessary to counterweight the constant-width asymmetric catwalk on the inner side to prevent the tilting of the catwalk,when rehanging the catwalks to the main cables.
作者
李陆平
赵鹍鹏
冯广胜
胡腾飞
LI Luping;ZHAO Kunpeng;FENG Guangsheng;HU Tengfei(China Railway Major Bridge Engineering Group Co.,Ltd.,Wuhan 430050,China;The Fifth Engineering Co.,Ltd.,China Railway Major Bridge Engineering Group,Jiujiang 332001,China)
出处
《桥梁建设》
北大核心
2025年第6期1-7,共7页
Bridge Construction
基金
中国中铁股份有限公司科技研究开发计划课题(2022-专项-03)。
关键词
悬索桥
不同垂度四主缆
等宽非对称猫道
托架索架设
承重索穿塔
施工技术
suspension bridge
four main cables with different sag
constant-width asymmetric catwalk
cable installation with brackets
load-bearing cable threading
construction technique
