大跨度索穹顶结构抗火性能分析  

Fire resistance analysis of large-span cable dome structure

作　　者：刘学春[1] 张爱林[1] 谢伟伟[1] 葛家琪[2] 张国军[2] 

机构地区：[1]北京工业大学建筑工程学院,北京100124 [2]中国航空规划建设发展有限公司,北京100120

出　　处：《建筑结构学报》2012年第4期31-39,共9页Journal of Building Structures

基　　金：国家自然科学基金重点项目(51038006);北京工业大学城市与工程安全减灾教育部重点实验室项目

摘　　要：根据内蒙古伊旗全民健身体育中心工程设计的需要,对大跨度索穹顶结构进行抗火性能分析。以温度-结构耦合为基本方法,基于大空间空气升温模型,考虑高温下材料的非线性,分析了结构在不同火灾工况下的响应,得到火灾下索穹顶结构变形、节点位移、杆件预应力损失的基本规律。研究表明:肋环型索穹顶结构侧向刚度较弱,对偏心火灾敏感,火灾下的挠度超限和侧向变形是导致结构失效和非结构构件提前破坏的主要原因;脊索尤其内脊索是火灾下预应力损失较为严重的杆件,中撑杆侧向位移控制是肋环形索穹顶结构抗火设计的重点。针对肋环形索穹顶结构侧向刚度较弱的缺点,在中撑杆上节点部位加设一道环向杆件进行结构体系的改进,可使结构的抗火性能得到较大改善。To satisfy the need for the design of the National Fitness Center in Ejin Horo Banner,Inner Mongolia,the fire resistance performance of the cable dome structural system is studied in the paper.Considering material nonlinearity under high temperature,the structural response under different fire conditions and the basic laws of structural deformation,node displacement and prestressing force loss were analyzed,based on thermal-structural coupling method and the model of atmosphere temperature ascending in large space.This research indicates that the lateral stiffness of Geiger cable dome structure is weak and it is susceptible to eccentric fire load;the eccessive deflection and lateral deformation are major reasons for structural failure and nonstructural components＇ early damage under fire.The pestressing force loss of the ridge cables,especially the inner ridge cables,is more serious,and the struts should be considered as key parts in the fire resistance design.Finally,for the deficiency of plane stiffness in Geiger cable dome structure,the improvement of adding loop rigid rods on the upper node of struts can benefit the fire resistance performance significantly.

关 键 词：大跨度索穹顶结构 抗火分析 温度-结构耦合 结构响应 预应力损失 

分 类 号：TU393.3[建筑科学—结构工程] TU394.02