中粮前海总部大楼结构选型综述

Overview on structural selection of COFCO Qianhai Headquarters Building

中粮前海总部大楼项目为带伸臂的钢管混凝土框架⁃钢筋混凝土核心筒结构,塔楼楼冠设有高×宽为56m×28.5m的通透单层大索网幕墙。结构选型上,钢结构用以解决标准层楼盖跨度大、楼冠大悬挑的受力问题,钢筋混凝土筒体则兼顾项目的经济性。考虑不同时期周边环境特征,通过风洞试验确定塔楼风荷载合理取值,并优化塔楼伸臂桁架道数的设计。针对伸臂桁架中斜腹杆采用箱形截面时施工困难、质量不易保证的痛点,提出了一种新型斜腹杆,并给出有限元等效模拟方法。为满足楼冠大索网幕墙的建筑效果,采用下部圆钢管混凝土柱⁃上部方钢管混凝土柱的复杂转换设计,即小截面托大截面类型的转换。通过拟静力试验验证新型圆⁃方钢管混凝土柱转换节点的合理性与可靠性。最后综合介绍整体结构的抗震性能化设计内容。项目设计思路与创新设想可供类似项目参考。

The COFCO Qianhai Headquarters Building project is a steel tube concrete frame with outriggers⁃reinforced concrete core tube structure.The tower crown is equipped with a transparent single⁃layer large cable net curtain wall with a height and width of 56m×28.5m.In terms of structural selection,the steel structure is adopted to solve the problems of large span floor at standard storey and large cantilevered tower crown,while the reinforced concrete core tube takes into account the economy of the project.Taking into account the characteristics of the surrounding environment at different times,the wind load on the tower was reasonably determined through wind tunnel tests,and the design of the tower′s cantilever truss was optimized.Aiming at the pain points of the construction difficulty and the quality difficult to guarantee when diagonal web members in outrigger trusses adopt box⁃shaped sections,a new type of diagonal web member was proposed,and finite element equivalent simulation method was given.In order to meet the architectural effect of the large cable net curtain wall of the tower crown,the complex conversion design of the lower round concrete⁃filled steel tube column and the upper square concrete⁃filled steel tube column is adopted,which is a small⁃section supporting large⁃section type.The rationality and reliability of the round⁃square concrete⁃filled steel tube column conversion node were verified through the quasi⁃static test.Finally,a comprehensive overview of the seismic performance⁃based design of the structure was presented.The project design ideas and innovative ideas can be used for reference in similar projects.