框架-核心筒-外剪力墙结构体系的抗震性能化分析

Seismic performance analysis of the frame-core-external shear wall structural system

开元壹号B栋主塔楼结构高度166.85m,为B级高度超限高层,采用了钢筋混凝土框架+核心筒的结构体系,该建筑弱轴方向结构整体高宽比6.9,核心筒高宽比20.6,远超高规所示经济性的高宽比。对抗侧力构件的布置(内筒外不增设剪力墙、内筒外底部楼层增设剪力墙、内筒外全楼层增设剪力墙)进行了方案比选,设定了D级结构抗震性能设计指标,采用动力弹塑性方法验证了大震下的各主要抗侧力构件的抗震性能,进一步尝试使用极罕遇地震动力弹塑性时程分析,找出了该结构体系的对薄弱的部位及构件,探明各构件的损伤程度,证明了框架-核心筒-外剪力墙结构体系是一种高承载力-高延性的结构抗侧力体系。并采取一系列的增强措施,如低楼层框架柱内设型钢、提高内筒外剪力墙的配筋率、在底层型钢柱内的角部设置圆形箍筋,加强了构件的延性。

The structural height of the main tower of Kaiyuanyihao is 166.85m,which is a class B height super-limited high-rise,using the structural system of reinforced concrete frame-core,the overall structural height to width ratio in the weak axis direction of the building is 6.9,and the core height to width ratio is 20.6,which is much higher than the economic height to width ratio shown in the industry standard;this paper divides the arrangement of lateral force resisting members into three types,which are no additional shear wall outside the inner core,additional shear wall at the bottom floor outside the inner core,and additional shear wall at the whole floor outside the inner core.The three arrangements were compared and the seismic performance design index was set for the class D structure.The dynamic elastoplastic method was used to verify the seismic performance of the main lateral force resisting members under large earthquakes.Further attempts were made to use the very rare earthquake dynamic elastoplastic time analysis to find out the weak parts and members of the structural system,and to find out the degree of damage of each member,proving that the frame-core-external shear wall structural system is a structural lateral force resisting system with high bearing capacity and high ductility.The ductility of the members was strengthened by a series of strengthening measures,such as the installation of steel sections in the frame columns at low floors,increasing the reinforcement rate of the shear walls outside the inner core,and the installation of circular reinforcement stresses in the corners of the steel sections at the ground floor.