216 m大跨非对称刚构连续梁合龙施工关键技术

合龙施工是大跨度刚构连续梁悬臂施工的重要环节,是保证刚构连续梁整体线形、结构受力体系转换施工质量的关键,其施工技术虽然比较成熟,但是超大跨度非对称孔跨刚构连续梁超大体积合龙段施工比较少见,合龙方法及施工技术细节也各有不同,故研究合龙施工技术很有必要。本文结合南龙铁路闽江特大桥主桥(118+216+138+83) m大跨度非对称双线铁路刚构连续梁施工实例,介绍主跨216 m非对称刚构连续梁合龙施工关键技术,重点介绍非对称刚构连续梁施工合龙顺序、合龙吊架设计、中跨合龙传力顶推装置设计及锁定技术、水袋预压、混凝土浇筑及体系转换等技术及施工控制要点,为类似工程施工提供参考。

Key Technique for Closure Construction of Asymmetric Rigid Frame Continuous Beam with 216 m Long-span

Closure construction is an important part of the cantilever construction of long-span rigid frame continuous beams.It is the key to ensure the overall linearity of the rigid frame continuous beams and the structural quality of system conversion construction.Although its construction technique is relatively mature,the construction of ultra-long-span asymmetric hole-span rigid frame continuous beams with super-large volumes is relatively rare.In addition,the details of construction methods and construction techniques are different.Therefore,it is necessary to study the construction technique of closures.This paper considered the example of a large-span asymmetric double-track railway continuous beam with a main span of(118+216+138+83)m on Minjiang Bridge of Nanlong Railway,and introduced the key technology on the construction of a 216 m(the length of the main span)asymmetric rigid-frame continuous beam.The key points of this paper are construction sequence of asymmetric rigid frame continuous beams,the design of the closure hanger,the design and technology of the mid-span closure force-pushing device,water bag preloading,concrete pouring and system conversion.And other key points for construction controlling are also considered,thus providing a reference for similar projects.