嘉德艺术中心结构模型振动台试验与竖向地震作用分析

嘉德艺术中心是同时带有大悬臂和大跨转换层的复杂结构，为保证该结构的抗震安全性，进行了1:16的缩比振动台试验，并利用ABAQUS进行了弹塑性分析。研究了结构的动力特性，研究了结构在8度多遇、设防、罕遇地震及9度罕遇地震下的加速度响应、位移响应及损伤过程。并讨论了大悬臂桁架和大跨转换层桁架竖向地震作用计算方法。研究结果表明:该结构具有良好的变形能力和延性，具有足够的抗震储备能力，满足规范"小震不坏，中震可修，大震不倒"的设防要求；采用竖向振型分解反应谱法计算的竖向地震作用并不一定大于规范简化方法的结果，实际设计中宜取两者的包络；且对于8度抗震设防的大悬臂桁架和大跨转换层桁架，规范简化方法计算的竖向地震作用偏小，宜取重力荷载代表值的15%计算竖向地震作用。

STUDY ON VERTICAL SEISMIC ACTION AND SHAKING TABLE TEST OF GUARDIAN ART CENTER

The Guardian Art Center is a complex structure with large cantilevers and large span transfer trusses. To ensure its aseismic safety, a 1:16 scaled shaking table test is carried out and the corresponding nonlinear time history analysis is conducted by using ABAQUS. The dynamic characteristics of the structure are studied firstly, and then the acceleration, displacement, frequency, and damage process are studied in both horizontal and vertical directions due to the rare earthquake of 8-degree fortification and the rare earthquake of 9-degree fortification. Finally, the calculation methods of vertical seismic action of a cantilever truss and a long span transfer truss are discussed. The results show that the structure has the great capacity of deformation and ductility and enough collapse margin ratio to meet the requirements of the ‘damage not occur under frequency earthquake, damage is repairable under moderate earthquake, and collapse not occur under rare earthquake’. The vertical seismic action calculated by the vertical mode decomposition response spectrum method is not necessarily larger than the result of the simplified method, and the two envelopes should be adopted in an actual design. For the studied complex structure with a large cantilever truss and a long-span transfer truss, the vertical seismic action calculated by the simplified method is smaller than the experimental result. Hence, 15% of the seismic weight is suggested to calculate the vertical seismic action.