弦支穹顶结构体系的分类及结构特性分析

Classification and Analysis of Structure Feature for Suspendome System

针对弦支穹顶结构体系,提出了3种分类方法,分别是按照上弦杆件刚接、铰接划分,按照下弦拉索的类型划分以及按照上层单层网壳形式划分。对肋环型、施威德勒型、联方型、凯威特型、三向网格、短程线型以及组合型等各种弦支穹顶结构形式进行了结构特性分析。联方型和凯威特型单层球面网壳,易于布置拉索和撑杆且上弦网格均匀,均适于构成弦支穹顶体系,而且由于上弦网格均匀,结构对称,杆件种类较少,设计和施工比较简便,所以联方型、凯威特型弦支穹顶是最有效的弦支穹顶结构形式。按照工程应用方便的原则,推荐采用按照单层网壳形式划分的分类方法,尤其是采用联方型、凯威特型以及联方-凯威特型弦支穹顶结构形式。

Three classification methods are presented for suspendome system.Three methods are classified by upper cord member connections including pin joint and fixed joint,lower cable types including flexible cable and rigid tube,and the forms of upper single-layer lattice shell.The structural features of suspendome including rib-patterned,Schwedler,Lamella, Kiewitt,geodesic,three-dimensional lattice and combination among these types are analyzed .Lamella and Kiewitt lattices benefit laying cables and members,and the upper lattices of the two lattice shells are uniform,so Lamella and Kiewitt lattices are fit to form suspendome system.And because the upper lattices are uniform,the structure is symmetric, the member type is lesser,and the design and construction are relatively simple,Lamella and Kiewitt suspendomes are the most effective types.Under the rule of making engineering application convenient,the method by the forms of single-layer lattice shell is adopted,and especially the Lamella,Kiewitt and Lamella-Kiewitt suspendomes are adopted.