武汉江城之门大跨刚性连体超高层混合结构收缩徐变分析

Shrinkage and creep analysis of super high-rise hybrid structure with large-span rigid conjoined structure of River City Gate of Wuhan

武汉江城之门为双塔高位连体的门形超高层建筑,建筑高度241.9m,采用钢管混凝土柱框架+核心筒+加强层+连体巨型跨层桁架结构体系,核心筒角部及相交处内嵌钢骨,部分楼层内嵌钢板。采用SAP2000软件分别建立基于CEB-FIP 90、CEB-FIP 2010、GL2000理论的分析模型和无连体单塔模型,进行了考虑收缩徐变的非线性阶段施工模拟分析,对比了典型竖向构件变形和内力重分布结果。分析结果表明,伸臂桁架可有效平衡外框柱和核心筒的竖向变形差异;高位刚性连体的布置加大了外框柱和核心筒的竖向变形差异,其差异主要为弹性变形,收缩徐变引起的附加变形差异较小;混凝土收缩徐变带来的竖向构件轴力重分布表现为核心筒剪力墙卸载,外框柱和剪力墙内嵌钢骨加载,轴力变化最大值位于连体相邻下部楼层;对伸臂桁架和腰桁架内力影响主要体现为弦杆轴力的增大。

The River City Gate of Wuhan is a twin-tower high-position conjoined door-shaped super high-rise building with the architectural height of 241.9m.It adopts a concrete filled steel tube column frame+core tube+reinforcing layer+connected giant cross-layer truss structural system.Steel bones are embedded in the corners and intersection of the core tube,and steel plates are embedded in some floors.SAP2000 software was used to establish the analysis model and the non-conjoined single tower model based on CEB-FIP 90,CEB-FIP 2010 and GL2000 theories.The non-linear construction simulation analysis considering shrinkage and creep was carried out,and the deformation and internal force redistribution results of typical vertical members were compared.The analysis results show that the outrigger truss can balance the vertical deformation difference between the outer frame column and the core tube effectively.The vertical deformation difference between the outer frame column and the core tube is increased by the arrangement of high-position rigid conjoined structure,and the difference is mainly elastic deformation,and the additional deformation caused by shrinkage and creep is small.The redistribution of axial force of vertical members caused by concrete shrinkage and creep is manifested as the unloading of shear wall of core tube and the loading of steel bones embedded in the outer frame column and shear wall.The maximum variation of axial force is located in the lower floors adjacent to the conjoined structure.The influence on the internal force of outrigger truss and waist truss is mainly reflected in the increase of string axial force.