摘要
马鞍山长江公铁大桥主航道桥为双主跨1120 m的三塔钢桁梁斜拉桥,Z4号桥塔采用纵、横向均为A形的四肢空间钢-混组合结构,塔高345 m。上塔柱采用Q500qE钢结构,高118.5 m,钢-混凝土结合段高3 m,钢塔共分39个吊装节段,钢塔大节段在工厂采用匹配法制造,分节段船运至Z4号桥塔旁,采用塔旁塔式起重机吊装。在钢塔施工过程中,按照“2+1”或“3+1”节段进行立式总拼,通过加强厂内加工制造工艺质量控制措施,解决了高强度、超厚板、大截面钢塔焊接和拼装难题;研制15000 t·m智能化塔式起重机,通过合理布设其站位、优选附墙结构及研制新型吊具,实现了钢塔大节段高空安全吊装;钢-混结合段采用“支撑架+定位匹配架”辅助施工,解决了钢-混结合段空中定位、限位难题,通过开展灌浆工艺试验及优化混凝土配合比解决了大截面超厚承压板下混凝土填充密实难题;通过合理优化多肢钢塔合龙段分块制造、安装工艺及设置定位桁架,实现了四肢钢塔高空精确对位合龙;通过钢塔节段厂内制造测量控制、施工前统一控制基准,以及施工中采用测回法、对向观测与差分法结合的方式进行安装测量控制,实现了超高桥塔施工测量控制。
The main navigation channel bridge of Maanshan Changjiang River Rail-cum-Road Bridge is a steel truss girder cable-stayed bridge,featuring three pylons that create two main spans of 1120 m.The pylon Z4 is a four-leg spatial steel-concrete composite structure rising 345 m,which is A-shaped when seen from both the longitudinal and transverse directions.The upper pylon section is made of Q500qE,with a total length of 118.5 m,the steel-concrete joint section measures 3 m long,and the steel legs were divided into 39 sections for the match-cast fabrication in the factory.The sections were shipped to the site of pylon Z4 for erection by the hammerhead cranes.During the construction,the steel leg sections were vertically assembled in the"2+1"and"3+1"manners.The manufacturing and quality control measures were selected purposely to facilitate the welding and assembly of the steel pylon sections with high strength,very thick plates and large cross-section.To achieve the safe overhead hoisting and erection of the steel pylon segments,intelligent hammerhead cranes with a capacity of 15000 t·m were developed,and the locations of the cranes as well as the type of buttressed walls matching best with the segments were selected for the best assembly effect,and riggings were tailored for the project.The steel-concrete composite joint section was constructed using the supporting frames and positioning trusses,to facilitate the positioning and restraining of the steel-concrete joint section.The grouting tests were conducted and the mix proportion of the concrete was optimized,to allow the concrete to be densely filled beneath the very thick bearing plate with large cross-section.The key section of the multi-leg steel pylon structure was manufactured in pieces.Proper installation techniques and positioning trusses were employed to achieve the precise overhead matching and closing of the four-leg pylon.The installation and measurement of the steel pylon sections were controlled.Uniform control benchmark was determined before the start of the construction,and installation and measurement control were conducted during the construction based on the observation set method,target observation and differential method,to achieve the construction measuring control of the high-rise pylon.
作者
徐敏
XU Min(Hefei Railway Hub Project Construction Headquarters(Ning′an Railway Co.,Ltd.),China Railway Shanghai Group Co.,Ltd.,Hefei 230011,China)
出处
《桥梁建设》
北大核心
2025年第3期11-19,共9页
Bridge Construction
基金
国家十四五重点研发计划项目(2022YFB3706405)
中国中铁股份有限公司科技研究开发计划项目(2021-专项-03)
中国铁路上海局集团有限公司科研计划课题(2022152)。
关键词
公路铁路两用桥
斜拉桥
钢-混组合桥塔
钢-混结合段
四肢钢塔合龙
测量控制
施工技术
rail-cum-road bridge
cable-stayed bridge
steel-concrete composite pylon
steel-concrete joint section
four-leg steel pylon closure
measurement control
construction technique
作者简介
徐敏,1985-,男,高级工程师,2008年毕业于安徽建筑大学土木工程专业,工学学士。研究方向:桥梁、高铁线路施工,E-mail:13705537223@126.com。
