空间外网格与多高层混合结构性能设计研究

Performance-based design and study on hybrid structure combined with outer steel grid and inner high-rise building

以成都博物馆工程为背景,针对空间外钢网格-钢框架-钢筋混凝土核心筒混合结构性能化设计的关键问题进行分析并对该结构进行振动台试验和设计方法研究。开展结构的概念设计,针对结构特性制定抗震性能目标和稳定性能指标;通过弹性、弹塑性时程分析进行结构地震响应研究,并通过振动台试验验证时程分析的结果;对空间外钢网格进行整体稳定性及关键构件失效后结构的防倒塌能力分析。时程分析和振动台试验结果表明：工程采用外钢网格衔接内部钢框架及内部钢筋混凝土核心筒的结构形式是可行的。时程分析得出,结构5-15m标高存在薄弱部位,但在罕遇地震下结构能够满足预期抗震性能目标,结构塑性首先出现在核心筒连梁,并大量开展;而钢结构塑性开展较少;空间钢结构稳定性良好,并且具有较高的冗余度,能够保证少数关键构件破坏下结构不倒塌。

With Chengdu Museum project as the background,the key problems involved in the performance-based structural design of the hybrid structure including outer steel grids,steel frame and inner reinforced concrete corewall were analyzed,the study of design methods and the shaking table test of the structure were conducted. The seismic concept design was conducted. Performance-based seismic design goals and stability performance indicators were defined based on the structural characteristics. The research on structural seismic response was made through elastic analysis and elastic-plastic time-history analysis and and the results of the time-history analysis were verified by the shaking table test. The overall stability of the outer steel grid and the anti-collapse capability of the structure after failure of key components were analyzed. Time-history analysis and shaking table test results show that it is feasible to use external steel grids to connect the internal steel frame and the internal reinforced concrete corewall. Time-history analysis shows that there are weak parts between the 5 - 15 m elevations of the structure,but the structure can meet the expected seismic performance target under rare earthquakes. The structural plasticity first appears in the corewall coupling beams and is carried out in large quantities;while the plasticity in steel structure is less developed; the spatial steel structure has good stability and high redundancy,which can ensure that the structure would not collapse when a few key components are destroyed.