超大跨度张弦结构多索索夹偏心节点设计及有限元分析

Design and finite element analysis of multi-cable and eccentric cable clamp joint for super-span string structure

对于超大跨度张弦结构,其撑杆下端的索夹节点是影响张弦结构成型的关键因素。由于外圈环向索的受力较大,超大直径拉索的捻制成型工艺尚未成熟,外圈环向索需采取并排多索的形式才能满足其受力要求,索夹节点相连构件数量多且受力大。基于贵阳奥林匹克体育中心(二期)主体育馆项目大跨度弦支穹顶结构,分析多索索夹节点的设计重难点,通过综合对比多种索槽布置方式,提出适用于超大跨度张弦结构的多索索夹偏心节点,并对该偏心节点进行整体受力和节点有限元分析。结果表明,多索索夹偏心节点对结构索力分布影响较小;该偏心节点设计符合计算假定,具有较高的承载力和抗滑移能力,有效解决了多索索夹节点连接、索夹安装及拉索更换等问题。

For super-span string structure,cable clamp joint at the bottom of strut is the key influencing factor of string structure forming.Due to the large internal force of outer ring hoop cable and immature production process of ultra large-diameter cable,parallel arrangement of multi-cable is usually adopted to satisfy the bearing requirements of outer ring hoop cable,and the corresponding cable clamp joint with large internal forces is connected to relatively large number of structural members.Based on the large-span suspended dome in the main gymnasium of Guiyang Olympic Sports Center(second stage),the design important and difficult key points of multi-cable clamp joint were analyzed.Through synthetical comparison of several arrangement forms of cable groove,the multi-cable and eccentric cable clamp joint for super-span string structure was proposed,and the integral force analysis and finite element analysis were conducted for the eccentric joint.The results show that multi-cable and eccentric cable clamp joint has less influence on structural cable force distribution.The design of the eccentric joint accords with the calculation assumption and has high bearing capacity and anti-slip ability,can effectively solve the problem of multi-cable cable clamp connection,cable clamp installation and cable replacement.