边支点临时锚固大跨钢桁拱桥主拱合龙技术  

Closure Technology of Main Arch of Large⁃span Steel Truss Arch Bridge with Temporary Anchorage of Side Supports

作　　者：汪来发 李业勋 WANG Laifa;LI Yexun(CCCC Third Harbor Engineering Co.,Ltd.,Shanghai200030,China;Laboratory of Engineering Structure of CCCC,Shanghai200030,China)

机构地区：[1]中交第三航务工程局有限公司,上海200030 [2]中交工程结构重点实验室,上海200030

出　　处：《施工技术(中英文)》2025年第6期68-73,120,共7页Construction Technology

基　　金：中交第三航务工程局有限公司重点研发项目(2020⁃14,2022⁃10)。

摘　　要：采用悬臂法拼装的3跨钢桁拱桥在施工中跨时一般通过在边跨配重以保证结构的抗倾覆稳定性,中跨主拱合龙一般通过纵移整体拱架及升降边支点,实现主拱姿态整体调整及完成主拱的无应力合龙。3跨钢桁拱桥的边、中跨比一般>1/4,对于边、中跨比小,采用常规配重方法无法满足需求时,以体外预应力锚固边支点来提升主拱悬臂端抗倾覆稳定性,但也引发边支点锚固后无法通过支座处顶推或升降来调整钢桁拱姿态问题。利用有限元软件计算主拱预偏、预降量,通过扣锚索索力微调消除合龙口两侧高差,通过基于杆件吊装顺序的结构变形分析计算合龙口距离变化,利用温度变化实现主拱高精度合龙。The three⁃span steel truss arch bridge assembled by cantilever generally ensures the stability of the structure against overturning by adding weight to the side span during construction.The closure of the main arch in the middle span is generally achieved by longitudinally moving the overall arch frame and lifting the side supports to achieve the overall adjustment of the main arch posture and complete the unstressed closure of the main arch.The side to mid span ratio of a three⁃span steel truss arch bridge is generally greater than 1/4.When the side to mid span ratio is small and conventional weight balancing methods can not meet the requirements,external prestress is used to anchor the side supports to improve the anti overturning stability of the main arch.However,it also leads to the problem that the steel truss arch posture can not be adjusted through pushing or lifting at the supports after anchoring the side supports.This paper uses finite element software to accurately calculate the pre⁃offsetting and pre reduction values of the main arch.By adjusting the tension of the anchor cable,the height difference on both sides of the closure is eliminated.Through structural deformation analysis based on the lifting sequence of the members,the distance change of the closure is accurately calculated,and the highprecision closure of the main arch is achieved by utilizing temperature changes.This paper verifies the conclusion that steel truss arch bridges with temporary anchorage of side supports can also achieve highprecision closure of the main arch.

关 键 词：桥梁 拱桥 钢桁拱 大跨度 合龙 预偏 施工技术 

分 类 号：U445[建筑科学—桥梁与隧道工程]