某斜交网格筒中筒超限高层结构设计

Structural design of an out⁃of⁃code high⁃rise oblique grid tube⁃in⁃tube structure

某斜交网格筒中筒超限高层项目结构高度158m,采用钢筋混凝土核心筒与钢斜交网格外筒组成的筒中筒结构体系。外筒由钢斜柱和水平环梁组成,同时存在楼面开大洞、竖向刚度突变、斜柱、穿层柱等不规则情况。对内筒分别采用钢筋混凝土内筒、钢框架支撑内筒两种结构形式进行对比分析,对外筒钢斜柱分别采用箱形截面、圆形截面两种截面形式进行对比分析。结果表明,箱形截面钢斜交网格外筒-钢筋混凝土内筒结构体系施工操作更为简便,经济性更为优越,更能满足建筑要求效果。主要介绍了结构超限情况及超限措施、斜交网格关键节点有限元分析、罕遇地震动力弹塑性分析,验证了钢筋混凝土核心筒与钢斜交网格外筒组成的筒中筒结构体系具有良好的抗震性能。

The structural height of an oblique grid tube⁃in⁃tube out⁃of⁃code high⁃rise project is 158m.The tube⁃in⁃tube structural system composed of reinforced concrete core tube and steel oblique grid outer tube is adopted.The outer tube is composed of steel inclined columns and horizontal ring beams.There are irregular situations such as large openings on the floor,sudden change of vertical stiffness,inclined columns and through⁃layer columns.The two structural forms of reinforced concrete inner tube and steel frame⁃braced inner tube were compared and analyzed.The steel inclined column of outer tube was compared and analyzed by box section and circular section respectively.The results show that the construction operation of the box section steel oblique grid outer tube⁃reinforced concrete inner tube structure system is simpler and more economical,which can better meet the requirements of the building.The out⁃of⁃code situation and measures of the structure,the finite element analysis of the key nodes of the oblique grid,and the dynamic elastic⁃plastic analysis of the rare earthquake were mainly introduced.It is verified that the tube⁃in⁃tube structure system composed of reinforced concrete core tube and steel oblique grid outer tube has good seismic performance.