针对索穹顶结构脊索容易退出工作、施工技术要求高、边环梁压力大等问题,给出一种把脊索换成刚性构件而成的刚性索穹顶结构,并采用均匀设计方法对刚性索穹顶结构进行近似优化分析.选用U12(37)均匀设计表,以一个跨度为60 m,承受轴对称均布荷载作用的肋环型刚性索穹顶结构为例进行分析,建立结果指标与设计参数之间的近似函数关系,获得近似优化的刚性索穹顶,并通过极值分析证明结果的可靠性.在此基础上,通过与相应索穹顶结构的分析比较,结果表明,刚性索穹顶结构具有上弦构件受拉、安装时只需张拉斜索,当向下荷载增大时,边环梁压力将逐渐减小.
There are some problems for cable dome structures,like the ridge cables are easy to be out of work,the construction requires high technology and outermost ring beams are always with high compressive force.To solve these problems,a type of rigid cable dome structure was presented,replacing ridge cables by rigid members.Approximate optimization was carried out using uniform design method.As an example,a 60m-span Geiger rigid cable dome subjected to symmetrical uniform load was analyzed using U12(37) uniform table.First the approximate functional relation between outcome indicators and design parameters was established.Then an approximate optimum rigid cable dome structure was obtained and the optimum result was verified by extreme value analysis.On this basis,comparing with the conventional cable dome,conclusions are arrived that the upper chords of rigid cable dome structure are under tension,only diagonal cables are necessary to be tensioned during the structural construction and the force of outermost ring beam decrease gradually with the load increasing.