核心筒领先层数对超高层结构竖向变形影响的分析

Analysis of the Influence of the Number of Leading Layers of the Core Tube on the Vertical Deformation of Super High-Rise Structures

针对超高层建筑在施工过程中两种不同材料产生的竖向变形累计带给结构附加应力这一问题,对结构进行施工模拟是很有必要的.本文通过有限元分析软件Midas gen将结构划分为22个施工阶段,利用子结构状态叠加法对施工过程进行了精确模拟.结合本结构受力特点,在模拟过程中综合考虑了材料特性、边界条件及施工荷载等因素,分析了核心筒不同领先层数对超高层结构竖向变形、两者竖向变形差及外框架柱内力分布产生的影响.结果表明:混凝土的收缩徐变约占结构总变形的40%.因此,混凝土收缩徐变效应产生的影响不可忽略.通过模拟可知,核心筒领先不同层数会对结构竖向变形和内力产生较大影响,同时得出核心筒领先外框架6层时,两者的竖向变形差最小,其值为23.48 mm.通过施工模拟得出最佳领先层数,有效减小核心筒与外框架之间的竖向变形差,从而减小附加应力,为类似工程提供一定施工技术参考.

In view of the problem that the vertical deformation caused by two different materials brings the added stress to the structure during the construction of super high-rise building,it is necessary to simulate the construction of the structure.In this study,the structure was divided into 22 construction stages by finite element analysis software MIDAS/Gen,and the construction process was accurately simulated by substructure state superposition method.The factors such as material characteristics,boundary conditions and construction load were comprehensively considered in the simulation process,and the effects of different leading floors of core tube on the vertical deformation of super high-rise structure,the different vertical deformation between them and the internal force distribution of outer frame column were analyzed.The results show that the shrinkage and creep of concrete accounts for about 40%of the total deformation of the structure,so the influence of concrete shrinkage and creep effect can not be ignored.Through the simulation,it can be seen that the number of different layers ahead of the core tube will have a great difference on the vertical deformation and internal force of the structure.At the same time,it was concluded that when the core tube is ahead of the outer frame for 6 layers,the vertical deformation difference is the smallest,and its value was 23.48 mm.The best leading layers were obtained through construction simulation,which can effectively reduce the vertical deformation difference between the core tube and the outer frame,so as to reduce the additional stress,and provide a certain construction technical reference for similar projects.