摘要:
潇河国际会展中心中间组团项目屋盖结构是最为复杂的部分,属于非连续大跨度正交斜放空间管桁架结构,分四个角顶、十字交通走廊玻璃顶、中心圆顶三部分,每个角顶钢桁架投影面积为6 575 m2,跨度为63 m,角顶斜向桁架最大跨度达88.7 m,为四边不等高造型,整个桁架节点复杂,存在钢管桁架(单曲弧度、双曲弧度)、变径、焊接球、箱形悬挑等多种形式,且高空作业量大、施工周期短、各专业交叉作业频繁。为有效降低施工难度和安全风险,保证施工质量及进度,采用“楼面(地面)拼装,分块整体累计提升+局部区域楼面原位高空直接散装”相结合的方法进行安装。为实现对大跨度正交斜放空间管桁架结构提升施工精度的控制,首先对地面拼装前预拱度设置进行研究,采用SAP 2000软件对分区错层提升、合拢、卸载进行模拟分析,精准计算提升过程变形值,同时采用非线性有限元模拟软件simufact welding对每榀桁架焊接变形进行分析,通过提升变形和焊接变形数据考虑预拱度;其次在地面拼装过程中采用三维激光扫描技术进行虚拟预拼装实现过程精度控制;最后在提升过程中对提升同步性进行实时控制,实现从地面拼装焊接及提升全过程控制精度,屋盖结构的施工精度达到了毫米级,有效地避免了施工作业返工,保证整个屋盖空间管桁架结构满足设计要求。
Abstract:
The roof structure of the middle group project of Xiaohe International Convention and Exhibition Center is the most complex part. It belongs to the discontinuous long-span orthogonal inclined space tube truss structure. It is divided into three parts: four corner roofs, glass roof of cross traffic corridor and central dome, the projected area of the corner top steel truss is 6 575 square meters, the span is 63 m, and the maximum span of the corner top oblique truss is 88.7 m, and a four-sided unequal height shape, the entire truss node is complex. There are various forms of steel pipe truss(single-curved arc, hyperbolic arc), variable diameter, welded ball, box-shaped cantilever, etc. The high-altitude workload is heavy, the construction period is short, and the professional cross-operation is frequent. In order to effectively reduce the construction difficulty and safety risks, and ensure the construction quality and progress, a combination of "floor(ground) assembly, block-by-block overall cumulative improvement + local floor in-situ direct bulk loading" is adopted for installation. In order to realize the control of the construction accuracy of the long-span orthogonally inclined space tube truss structure, the pre-camber setting before ground assembly was firstly studied, and the SAP 2000 software was used to simulate and analyze the staggered lifting, closing and unloading of the partitions, and calculate the lifting process accurately. At the same time, the nonlinear finite element simulation software simufact welding was used to analyze the welding deformation of each truss, and the pre-camber was considered by improving the deformation and welding deformation data; secondly, the virtual pre-assembly was realized by using 3D laser scanning technology during the ground assembly process; finally, in the lifting process, real-time control of the lifting synchronization was carried out to realize the research on the assembly welding from the ground and the control accuracy of the lifting process, which promoted the construction accuracy of the roof structure to reach the millimeter level, and avoided the rework of construction operations effectively and ensured that the entire roof space tube truss structure met the design requirements of the original state of the building.
登录
注册
点击查看大图
下载:
