某底部设置V型分叉柱超限高层建筑结构设计

Structural design of a transfinite high-rise building with V-shaped bifurcated columns at the bottom

介绍了上海某156m高超限高层塔楼结构设计,该塔楼南侧底部有两组V型分叉柱,节点交汇形式复杂,因其存在楼板开洞、大堂3层挑空、1~4层有V型分叉柱、五边形平面等特点,结构存在平面不规则、竖向不规则、局部不规则等4项不规则内容,属于超限高层结构。塔楼结构体系采用钢管混凝土柱+钢梁+混凝土核心筒混合结构,即达到装配预制率要求,也满足结构刚度和强度的需求。根据塔楼的不规则情况选取合适的抗震性能目标,并对V型分叉柱结构、底部剪力墙等关键构件进行中、大震的抗震性能验算。对V型分叉柱结构采用ABAQUS实体模型进行有限元分析验证确保安全性。整体结构采用SAUSAGE软件进行大震动力弹塑性时程分析,发现在核心筒中高区连梁跳层设置钢骨可明显减小大震层间位移角,提高结构抗倒塌性能。最后为确保关键构件的延性性能,采取有针对性加强措施。

This paper introduces the structural design of a 156-meter-high transfinite high-rise tower in Shanghai.It consists of two sets of V-shaped bifurcated columns at the bottom of the south side,and the node intersection form is quite complex.There are some special characteristics of the tower,for example,the local floor is partly opening,three levels of the lobby are empty,the V-shaped bifurcated columns exist from the first to the fourth floor and the plane shape is pentagon.Therefore,the tower is determined to be the transfinite high-rise structure because it contains four irregular contents such as plane irregularity,vertical irregularity,and local irregularity.To meet the requirements of assembly and prefabrication rate and the structural stiffness and strength,the tower used mixed structure system of concrete-filled steel columns,steel beam and concrete core tube.According to its irregular conditions,appropriate seismic performance targets were selected and seismic performance of key components such as V-shaped bifurcated column and the bottom shear wall were measured under medium and large earthquakes.ABAQUS solid model was used for finite element analysis and verification of V-shaped bifurcated column to ensure structural safety.The dynamic elastoplastic analysis of the whole structure under rare earthquake was carried out by SAUSAGE software.It is found that setting steel ribs at the coupling beam of jumped floor in the middle and high areas of the core tube can significantly reduce the inter-story displacement angle of large earthquakes and improve the collapse resistance of the structure.Finally,targeted structural strengthening measurements were taken to ensure the ductility of key components.