大风低温高空焊接环境下永定河主桥施工技术研究

STUDY ON CONSTRUCTION TECHNOLOGY FOR MAIN BRIDGE OF YONGDING RIVER BY HIGH-ALTITUDE WELDING UNDER STRONG WIND AND LOW TEMPERATURE CONDITION

目前,国内外针对单箱多室特大型桥梁的施工技术已经逐渐成熟。然而,在面临大风、低温等恶劣环境条件时,桥梁的焊接质量和变形控制成为工程中的难点。尤其是对于钢箱梁的施工和监控技术,还需要进一步研究。以永定河特大桥为背景,首先对主梁施工临时支架进行了有限元分析,重点阐述了临时支架安装和监控过程中的关键施工技术。其次详细介绍了单箱多室主梁的吊装技术。最后,分析了在大风、低温条件下主梁的焊接质量和变形控制技术,研究成果可为同类桥梁的施工和监测提供参考。

At present,the construction technology for single-box multi-chamber super-large bridges is more and more mature at home and abroad.However,under harsh conditions such as strong wings and low temperatures,it is difficult to control the welding quality and deformation of bridges.In particular,it is necessary to further study the construction and monitoring technology for steel box girders.Taking the super-large bridge of Yongding River as an example,the finite element analysis was carried out on the temporary support for main beam construction,and the key construction technology for temporary support installation and monitoring was described.Then the hoisting technology for the single-box multichamber main beam was detailed.Eventually,the technology for the welding quality and deformation control of main beams in strong winds and at low temperatures was analyzed.Results of this study provide a reference for the construction and monitoring of similar bridges.