大跨度单边开口拱形支撑煤棚工程钢结构施工技术

CONSTRUCTION TECHNOLOGY OF STEEL STRUCTURE WITH LONG SPAN SINGLE OPENING ARCH SUPPORTED COAL SHED PROJECT

由于大跨度单边开口钢结构支撑面积有限及自身重量的影响,其施工易产生明显的位移或偏移,这将带来局部的应力集中问题,降低结构的整体稳定性。且这种变形还会影响煤棚工程的施工顺序和施工进度,造成人力和资源的浪费。因此在施工过程中出现明显的位移或偏移时,需要设置临时支撑,组织临时支撑的施工流程并进行纠偏分析。以上海某发电厂煤棚改造工程中的大跨度拱架临时支撑为研究对象,提出了顶升高度50 mm、20 mm、1 mm的3种拱架纠偏方案,并对拱架变形、整体网架变形、施工中3区4区控制点的竖向变形、顶升过程中杆件应力进行了分析与讨论,最终建议采取顶升高度1 mm方式对拱架进行纠偏。

Due to the limited support area and large weight,the construction of large-span unilateral open steel structure is prone to produce obvious displacement or offset,which will bring local stress concentration problems and reduce the overall stability.The deformation will also affect the construction sequence and construction progress,resulting in a waste of manpower and resources.Therefore,it is necessary to set up temporary support,organize the construction process and carry out correction analysis.In this paper,the temporary support of large-span arch in the coal shed reconstruction project of Shanghai Wujing No.2 Power Plant is taken as the research object,and three kinds of arch rectification schemes with the jacking height of 50mm,20mm and 1mm are proposed.The deformation of the arch,the deformation of the overall grid,the vertical deformation of the control points in the three areas and four areas during the construction,and the stress of the members during the jacking process are analyzed and discussed.Finally,it is suggested that the jacking height of 1mm should be adopted to correct the deviation of the arch.