H形截面上弦张弦梁体系施工关键问题的研究

H形截面上弦平面张弦梁结构具有制作方便、便于节点连接的优点,但由于H钢截面构件具有平面外刚度较小的特点,对平面外的缺陷非常敏感,在施工过程中若对此没有采取有效措施,结构会发生平面外失稳,以至无法施工。通过有限元方法三维整体建模,对张弦梁施工过程中的预应力张拉和工作阶段的全过程进行模拟及分析,研究该平面体系由于侧向支撑造成的空间效应,经反复比较提出可行的施工方案,指出应当注意的事项,保证了结构的安全施工,可供类似工程参考。

RESEARCH OF KEY PROBLEMS OF BSS CONSTRUCTION WITH TOP CHORDS OF H-SECTION

Planar BSS with top chords of H-section can be made conveniently,and its joints can be connected easily,but the system is sensitive to the imperfection out of plane because the member of H-section has small stiffness out of plane.The system will be unstable if no effective measure is taken in construction,which tells failure of construction.The paper builds spatial model of the system by FEA and analyzes the stages of prestress-tension and use,researches the spatial results brought by lateral supports,gives out rational scheme of construction,and points out the key problems,which ensures the safety of construction of BSS and can be a reference for other similar projects.