高层建筑单核心筒周边悬挂结构振动台试验研究OA北大核心CSTPCD

To evaluate the seismic responses,performance at the bottom of the core tube,damage characteristics,and failure modes of the structural system comprising a single-core tube with peripheral suspended floors,a 1/20 scale model was designed and manufactured for an investigation using a series of shaking table tests with triaxial excitation.These shaking table tests covered different seismic hazard levels,including the frequently occurred earthquake level,the design basis earthquake level,the maximum considered earthquake level and the extremely rare earthquake level.The damage-failure process of the core tube in the experiment started with damage at the coupling beams.As the damage further developed,seismic damage also occurred in shear walls at the bottom of the core tube.Finally,concrete crushing appeared at the bottom of the core tube.This process is featured by ductile characteristics,and therefore it can be proved that the single-core tube as the lateral force-resisting system has a two-stage earthquake-resistant mechanism(two seismic fortification lines).The experimental results indicate that the peak vertical acceleration responses of the suspended floors range from 2 to 4 times those of the core tube and therefore should be considered in structural design;the pin joints connecting floor beams with the core tube and hanging columns enhance the seismic performance.Hence,this study strongly supports the view that a well-designed single-core tube with peripheral suspended floors can be utilized as a form of tall building structures and satisfy the seismic requirements stipulated in modern design codes.The observed seismic performance provides a design reference of the investigated structural system which can be viewed as a highly efficient and reliable structural scheme for exploiting the space of dense districts in cities.