某大跨屋盖结构边界设计及研究

Design and study on structural boundary conditions of a large-span roof

为适应建筑要求及底部混凝土结构布置,某大跨屋盖采用双向正交正放网格结构.以单向滑动铰支座和下部6榀中心支撑框架为边界,与4个混凝土结构单元连接,控制径向推力,减小对底部混凝土结构的影响.通过抗侧极限承载力分析及罕遇地震下弹塑性时程分析,研究屋盖结构及中心支撑框架结构的抗侧性能.通过相关分析确定滑动支座的设计参数,运用有限元软件计算支座承载能力.结果表明,屋盖结构边界设置合理,中心支撑框架及支座能够满足罕遇地震设计要求.

Adapting to architectural requirement and concrete structural layout,the large-span roof chooses the two-way orthogonal space grid structure which is connected to four concrete structural units by oneway sliding bearings and six concentrically braced frames,to reduce radial horizonal thrust from roof to concrete structural units.The analysis of ultimate lateral resistance capacity as well as the dynamic elastoplastic time-history analysis under rare earthquake is conducted to study the lateral resistance of the roof structure and the braced frames.Simultaneously,design parameters of support bearings are determined by relevant calculations,and the bearing capacity is calculated by finite element software.Analysis results show that the structural system is reasonable,and the concentrically braced frames as well as support bearings meet the requirements of performance-based design under rare earthquake.