某商业综合体大悬挑结构设计与分析

Design and analysis of large cantilevered structure of a commercial complex

大悬挑结构因其跨度大、冗余度低常成为结构设计的难点及重点。某商业综合体悬挑结构最大跨度27.7m,采用六榀钢桁架作为主要受力构件。通过加大楼板厚度、设置楼面水平斜撑等构造措施,使结构传力可靠直接、变形协调合理。采用SAP2000等有限元软件对结构稳定性、防连续性倒塌、楼板应力、楼盖舒适度、复杂节点应力进行分析。结果表明,本工程悬挑结构满足正常使用极限状态及承载能力极限状态要求。通过大震弹塑性时程分析,悬挑区域钢结构基本处于弹性阶段,支承悬挑桁架的框架柱等关键构件满足结构抗震性能化设计要求。

Large cantilever structures is difficult and important in structure design due to the large span and low redundancy.The maximum span of the cantilever structure of a commercial complex is 27.7m,and six steel trusses are used as the main force member.Through structural measures such as increasing the thickness of the floor,setting up horizontal inclined braces,the force transmission of the structure is reliable and direct,and the deformation is coordinated and reasonable.Finite element softwares such as SAP2000 were used to analyze structural stability,anti-progressive collapse,floor stress,floor comfort,stress of complex nodes.The results show that the cantilever structure of the project meets the requirements of the serviceability limit state and the bearing capacity ultimate limit state.Through the analysis of elastic-plastic time history under rare earthquakes,the steel structure in the cantilever area is basically in the elastic stage.The key components such as frame columns supporting the cantilever trusses meet the requirements of performance-based seismic design.