索穹顶结构体系创新研究

我国自2009年开始建有跨度20 m左右的索穹顶，至2016年已建成跨度超百米的索穹顶结构。但回顾国内外所建成的该类空间结构，均属于传统Fuller构想张拉整体类索穹顶。其上、下弦节点只有1根垂直于水平面的撑杆，形式比较单一，如肋环型索穹顶，上弦节点的环向水平刚度较差。为此，提出了Fuller构想单撑杆（不垂直于水平面）类索穹顶，有利于增加结构跨度。并进一步提出了非Fuller构想多撑杆（下弦节点可设置2根、3根、4根撑杆）类索穹顶。这不仅可改善结构传力性能，而且又能减少斜杆（斜索）和环索数量，方便施工张拉成形。若采用多种撑杆（包括单撑杆）且多种方式设置，当上弦选用径向布置时可归纳称之为肋环系列索穹顶，当上弦选用葵花布置时可归纳称之为葵花系列索穹顶。由肋环系列索穹顶和葵花系列索穹顶可构成多种组合形式索穹顶。研究丰富了索穹顶结构形式、体系和类型，为索穹顶的设计和选型提供了新思路、新空间。

Structural system innovation of cable dome structures

Since the first domestic cable dome with 20 meters in diameter was built in 2009, large-span cable dome structures spacing over hundred meters had also been constructed in 2016. But overviewing all of these light-weighted spatial structures existing now at home and abroad, they mainly belong to traditional Fuller tensegrity with tedious configurations and single vertical strut bracing both at upper and lower chord nodes, such as Geiger domes which therefore have weak horizontal stiffness in the upper nodes. This paper presents a series of improved dome structures to achieve larger span by diagonal struts and further puts forward another series of new cable dome structures with two to four multiple struts, which can not only optimize structural performance but also reduce the quantity of diagonal (oblique cords) and ring cables to lessen the workload of tensioning process. When using different number of struts(including single one) and several ways of setting, domes with the upper chords radially distributed can be summarized as ‘ribbed series cable domes’ and the ones with their counterparts in sunflower layout can be summarized as ‘sunflower series cable domes’. Meanwhile, these two series of cable domes can also be combined to achieve composite forms. This study enriches the form, type and system of cable dome structures, and also provides new ideas for the design of cable dome.