深中通道伶仃洋大桥东索塔中横梁施工关键技术

Key construction techniques for middle beam of east cable tower ofLingdingyang Bridge on Shenzhen-Zhongshan Link

复杂海域环境超高索塔横梁施工质量与安全难以保证。其中,支架系统的设计与施工是决定横梁施工质量与安全的关键。依托伶仃洋大桥东索塔中横梁进行施工方案设计与优化,经方案比选:确定采用上拱式托架分层浇筑的总体施工方案,并提前预拉部分预应力束防止混凝土开裂。经计算分析:对浇筑分层进行优化,支架系统只承受首层混凝土浇筑荷载;拱式结构有效改善了托架牛腿处埋件受力。上拱式托架分层现浇方案满足主体结构质量要求及临时结构安全要求,保障了工程顺利实施,可为类似项目施工提供借鉴。

It is difficult to guarantee the construction quality and safety of ultra-high cable tower beam in complex sea areaenvironment.Among them,the design and construction of support system is the key to determine the quality and safety of beamconstruction.Based on the middle beam of the east cable tower of Lingdingyang Bridge,the design and optimization of theconstruction scheme are carried out.The overall construction scheme is determined to adopt the upper arch bracket for layeredcasting,and some prestressed tendons are pre-pulled in advance to prevent concrete cracking.After calculation and analysis,the casting layers are optimized,and the bracket system only bears the casting load of the first layer of concrete.The archstructure effectively improves the stress of the embedded parts at the brackets.The layered cast-in-place scheme of the upperarch bracket meets the quality requirements of the main structure and the safety requirements of the temporary structure,ensures the smooth implementation of the project,and provides reference for the construction of similar projects.