摘要
Abstract
The Nanjing Greenland Jinmao International Financial Center is a multi-functional tower with a total height of 499 m.It adopts a mega frame-core tube structural system with an outrigger truss strengthened layer,and the conventional ring truss is replaced with four arch structures.Due to the novelty of the structural type,the overall seismic performance of the structure and the performance of the arch structure need to be verified through experiments.In this study,a 1∶40 scale model of the tower structure was fabricated and investigated via shaking table tests.The dynamic properties of the model were identified,and the acceleration,displacement,and strain responses of the structure under different earthquake levels,i.e.,7-degree frequent,precautionary,and rare earthquakes,were investigated.The experimental results show that the structural design is reasonable.The multi-lateral force system composed of the mega frame,core tube,outrigger truss,and ring truss is found to have sufficient lateral stiffness and torsional stiffness.The maximum inter-story drift ratios of the structure under 7-degree frequent earthquakes and rare earthquakes are 1/593 and 1/95,respectively,which satisfy the expected seismic design performance,i.e.,1/500 and 1/100,respectively.The damage of the structure is found to mainly occur in the mega column and the corresponding coupling beam of the outer frame.The damage of the mega column is primarily tensile horizontal cracking,while the damage of the coupling beam is bending cracking at both ends.The damage of the core tube is restricted to a limited number of small cracks.Due to the lack of restriction of the core tube,the whipping effect of the tower crown is found to be significant.The average dynamic amplification coefficients above the 103rd floor range are between 2.6 and 9.3.This adverse effect should be considered when designing non-structural components,such as the envelope structure.The reduction of the section of the main lateral force-resisting members will cause sudden changes in the lateral stiffness and bearing capacity of the structure,which ofen lead to weak links.The floors between 54th and 73rd and above 86th where the mega column's section decreases were found to exhibit more cracks;thus,strengthening measures are recommended.关键词
超高层建筑/振动台试验/地震响应/损伤模式/抗震性能Key words
super high-rise building/shaking table test/seismic response/damage mode/seismic performance分类
土木建筑
