李鹏

摘要：兰州至海口国家高速公路陈家坝特大桥主跨为58m+90m+58m分幅式单箱双室变截面连续箱梁，连续箱梁采取挂篮悬浇方法。特大桥主墩高达19m，其0号段具有大尺寸、大体积及特级高处作业等特点，故对现浇模板支撑方案要求非常高，需满足承受巨大混凝土和施工荷载、沉降变形小、安全稳定性好、经济合理等要求。本项目根据桥墩高度、0号段结构尺寸等情况，采用螺旋管做支架承载主体，并对支撑的其他构部件进行了设计优化，最终设计出了符合高承载、低沉降、高安全及低成本的0号段支撑系统，顺利完成本项目大尺寸0号段的现浇施工。

Abstract： The main span of Chenjiaba Bridge of Lanzhou-Haikou National Expressway is 58m+90m+58m split-type single-box double-chamber variable-section continuous box girder， and continuous box girder adopts hanging basket suspension method. The main pier of the special bridge is up to 19 meters， and the  section has the characteristics of large size， large volume and special high-level operation. Therefore， the requirements for the cast-in-place formwork support scheme are very high， and it needs to meet the huge concrete and construction load， the small settlement deformation， good safety and stability， economical and other requirements. According to the height of the pier and the structural size of No.0 section， the project adopts a spiral pipe as the main body of the support， and optimizes the other components of the support. Finally， the No.0 support system conforming to high load bearing， low settlement， high safety and low cost is designed to successfully complete the cast-in-place construction of the large size No.0 section of the project.

关键词：连续箱梁;0号段模板支撑系统;高墩;大尺寸;螺旋管立柱

Key words： continuous box girder;No.0 section formwork support system;high pier;large size;spiral pipe column

中图分类号：U443.22                                    文献标识码：A                                  文章编号：1006-4311（2019）24-0185-04

0  引言

进行连续梁挂篮悬浇前，首先需进行0号段的墩顶现浇施工，然后以0号段作为安装挂篮的基础，方可以0号段作为标高、线型基准逐节悬浇连续梁的其他节段。可见控制0号段的施工质量是非常重要的，其直接影响到后续其他节段箱梁的施工质量及连续梁的整体线型，故0号段的施工质量是确保连续梁整体施工质量的关键。

随着设计、施工技术的进步，橋梁的连续梁向着跨度更大、桥面更宽、墩身更高方向发展，相应的0号段也更趋向于大尺寸、大体积及更高处作业等。采用传统的0号段支撑方案已难以适应上述0号段现浇施工的需要，所以工程技术人员扩展思路、采用先进材料、技术方可解决上述难题具有非常现实的工程意义。……