单层菱形网壳屋盖滑移施工空间张弦梁加强方案研究

Strengthening Scheme of Space Beam String for Sliding Construction of Single⁃layer Diamond Grid Shell Roof Structure

目前,滑移施工技术多用于双层或多层网格结构,单层屋盖滑移施工罕见,尤其是单层屋盖整体滑移施工。整体滑移对结构刚度和施工技术均有较高要求,有效控制滑移过程中过大的挠度与局部应力超标情况是顺利施工的关键,尤其对于整体刚度较弱的大跨度单层网格结构。为控制屋盖挠度和应力,基于北京星火站交通枢纽工程提出了空间张弦梁加强方案。通过有限元分析研究撑杆位置、数量与高度对结构刚度的影响。研究发现,空间张弦梁结构能有效控制网壳挠度,单撑杆和双撑杆张弦梁结构效率较高。

At present,sliding construction technology is mostly used for double⁃layer or multi⁃layer grid structures,and sliding construction technology for single⁃layer roofs is rare,especially integral sliding construction technology for single⁃layer roofs.Integral sliding has high requirements for structural stiffness and construction technology,so effectively controlling excessive deflection and local stress exceeding the limit during the sliding process is the key to smooth construction,especially for large⁃span and single⁃layer grid structures with weak overall stiffness.To control the deflection and stress of the roof,a space beam string reinforcement scheme was proposed based on Beijing Xinghuo Station transportation hub project.Through finite element analysis,the influence of the position,quantity,and height of the support rods on the structural stiffness was studied.It was found that the space beam string structure can effectively control the deflection of the grid shell,and the efficiency of single and double support rod beam string structures is higher.