对现有的弦支穹顶预应力施加方法进行总结,分析张拉环索方法所面临的环索与节点间摩擦损失的问题,提出在节点中设置转轴的概念,用滚动摩擦力代替滑动摩擦力来减小摩擦损失,并给出两种下弦节点方案——单体式新型节点和压板式新型节点,最后以某结构模型试验为背景给出一种具体节点实物设计,从多角度给出一款在张拉过程中可保证环索滑动,张拉完毕又可将环索固定避免滑动的撑杆下节点。
It is summarized the current methods of suspend-dome construction,the loss of prestress in loop cable caused by friction is studied in this paper.A new kind of roll cable-strut joint with a bearing is put forward to deal with the problem.Loss of prestress is reduced because of gliding friction replaced by roll friction.Two designs of roll cable-strut joint single-part roll cable-strut joint and press broad roll cable-strut joint are given under the concept of roll axis,as well as an actual design based on a suspend-dome model test.A kind of cable-strut joint which allows sliding of cable in prestress process and fixes the cable after construction is declared in different ways.