某超高结构加强层的“嵌固”作用讨论

Discussion on fixed effect of strengthened story in super high-rise building

伸臂桁架能够协调核心筒和外部框架的变形,使结构整体刚度显著增加,但是加强层引起结构整体刚度突变,对其以上楼层形成“嵌固”作用。兰州市某超限高层采用钢管混凝土框架-核心筒-伸臂桁架结构体系,对该结构进行分析表明加强层处倾覆力矩、剪力和墙肢拉应力产生突变且明显增大,罕遇地震下加强层处是仅次于结构底部的第二屈服部位。

Outrigger truss could coordinate the deformation between core tube and external frame,and make the fstructural integral stiffness increase significantly,however stiffness mutation is caused by strengthened story,which produced fixed effect.A super highrise concrete filled steel tube frame-core tube-outrigger truss structure is discussed,the results show that overturn moment,shear and tensile stress of wall panel change suddenly and increase obviously near strengthened story.This region is the second yield part of the structure under rare earthquake.