(北京市建筑设计研究院，100045)

［提要］新中国国际展览中心工程属2008奥运配套工程。一期工程为8个主展馆，各展馆平面均为71m×172m的矩形，分别由10榀倒三角形预应力立体管桁架构成屋盖体系，桁架跨度为70.2m。桁架下弦为方钢管，其余杆件均为圆钢管，预应力索穿于下弦杆内，支座采用铸钢单向铰支座。结合具体结构设计，进行了屋盖结构静力性能分析、单榀桁架出平面稳定验算、屋盖中震弹性验算、结构在罕遇地震作用下的弹塑性变形验算，并进行了单榀桁架断索及单榀桁架失效等极端工况下屋盖体系的抗连续倒塌验算。研究结果表明，结构各项性能均满足规范要求，并具有良好的静、动力受力性能。

［关键词］预应力立体管桁架；出平面稳定；中震弹性；大震弹塑性时程；连续倒塌

Prestressed Space Trusses Roof Structure Design of New China International Exhibition Center/Wei Dong, Ke Changhua, Wang Zhigang, Li Wenfeng(Beijing Institute of Architectural Design, Beijing 100045,China)

Abstract: New China International Exhibition Center is part of 2008 Olympic Games supporting project. It includes 8 main exhibition halls. Each exhibition hall is sized of 71m×172m and its steel roof is formed by ten 70.2 meter span inversion triangle section prestressed space trusses. In which, circular hollow sections are used as top chord and web members, and square hollow sections are used as bottom chord members with prestressed cable going through it. One way hinged cast steel supports are used for trusses. Integrating with structural design process, varies structural analysis on steel roof has been carried out, including static performance, single truss out plane stability, steel roof elastic analysis on occasional earthquake and whole structure elastic plastic time history analysis on rear earthquake. Two extreme cases of structure s progressive collapse are analyzed, including cable broken and one truss collapsed. The result of each analysis satisfies codes requirement. The analysis above proves that the whole structure has an excellent static and dynamic load bearing performance.

Keywords: prestressed space trusses; out plane stability; elastic plastic analysis; occasional and rear earthquake; progressive collapse