上海世博会中国国家馆屋盖钢结构设计与分析

Steel structure design and analysis on roof of China Pavilion at the World Expo 2010 Shanghai

2010年上海世博会中国国家馆上大下小、四棱台斗冠状外形使其屋盖竖向支撑较少,主梁梁端最大弯矩设计值达到4.86万kN.m,在建筑净高受限的条件下,采用常规主梁难以承担。介绍了屋盖桁架主梁、工字钢组合次梁、屋盖板设计中的难点、重点和相关构造做法,给出了在桁架端部采用钢板围套加强以减小弦杆局部弯矩、上弦杆贯通3片剪力墙利用栓钉的滑移减小弦杆巨大轴力在单片剪力墙墙肢内引起的剪力的措施。并由有限元分析验证了上述技术措施的可行性。最后进行了在n个点上生成n个随机体重、随机频率的人行荷载时程下的屋盖竖向振动全过程分析,多组随机分析即蒙特卡洛法分析结果表明,屋盖的竖向振动舒适度满足要求。

The roof of China Pavilion at the World Expo 2010 Shanghai has less vertical support, because its shape of bigger on top and smaller on the bottom is like an inverse quadrangular frustum pyramid crown. Maximal value of bending moment in the girder is 48 600kN · m. However, general girder could not bear it under the limitation of net storey height. Difficulties, emphases in design and correlative detailing of truss girder, I-steel composite secondary beam, roof slab were introduced. To reduce local moment in member, steel plates were used for reinforcement, encircling the chords between the upper and down chords at the end of truss girder. The huge axial forces from the chords would cause shear force in single shearing wall. In the ease of upper chords penetrating three shear wails, the stud slippage was utilized to reduce the shear force. The feasibility of the technological measures above has been proved by finite element analysis. Lastly, vertical vibration complete process of the roof was accomplished under n walking loads time history with random avoirdupois and random frequency. The results of large number random analysis namely Monte Carlo method show that the roof can satisfy the comfort demand.