龙潭长江大桥南北引桥钢混组合梁设计与施工研究

Design and Construction Study of Steel Concrete Composite Beams for the North-south Approach of Longtan Yangtze River Bridge

龙潭长江大桥南北引桥具有管线多、地面交通系统复杂、跨径布置控制因素多以及布墩位置条件受限等特点,经综合比选,采用结构简单、受力合理且施工便捷的钢混组合梁方案:30~60 m跨径采用等截面钢混组合梁,78~91 m跨径采用变截面钢混组合梁。主要从结构力学性能、安全性、经济性和施工便捷性等方面,分析、比选标准跨径和大跨径钢混组合梁的设计与施工方案。选用钢混组合梁时以标准化、工厂化、规模化、装配化作为设计理念,可提高生产效率和结构可靠性,减少高空作业风险,易于控制工程质量。项目中首次大规模将多主梁的槽形截面钢混组合梁应用于长江大桥,可为后续钢混组合梁设计与施工提供参考。

The north-south approach bridge of Longtan Yangtze River Bridge has the characteristics of multiple pipelines,complex ground transportation system,multiple control factors for span layout and limited pier location conditions.After comprehensive comparison and selection,steel concrete composite beam scheme with simple structure,reasonable stress and convenient construction are adopted.Constant section steel concrete composite beams are used for spans ranging from 30 m to 60 m,and variable section steel concrete composite beams are used for spans ranging from 78 m to 91 m.The research mainly analyzes and compares the design and construction plans of standard span and large span steel-concrete composite beams from the perspectives of structural mechanical performance,safety,economy,and construction convenience.The design concept of steel-concrete composite beams is standardization,industrialization,large-scale and assembly,which improves production efficiency and structural reliability,reduces the risk of high-altitude operations,makes it easy to control engineering quality.The project is the first large-scale application of multi main beam trough shaped steel concrete composite beams in the Yangtze River Bridge,providing reference for the design and construction of subsequent steel concrete composite beams.