Analysis Of Hysteretic Behavior Of A New Type Of Rocking Column With Buckling-restrained Longitudinal Reinforcement

The earthquake resilient structure has attracted more and more attention by the related scholars,how to design the structure which can restore its structural function immediately or do not happen severe damage after earthquake has been a significant direction in the field of earthquake engineering.So far,domestic and foreign scholars have conducted a series of studies on rocking and self-centering structures including system level and part level.The focus of this paper is on the column.In the existing researches,there are still a series of problems to be solved in the aspects of effectively avoiding the longitudinal buckling,improving the ductility and energy dissipation capacity,fully using its high rigidity and so on,whether it is the traditional frame column,the rocking column or the self-centering column.There are two most significant problems,firstly,the failure modes such as the longitudinal buckling of the frame column are still unavoidable,and secondly,the frame column cannot have the characteristics of large lateral stiffness and strong energy dissipation capacity.Aiming at this situation and combining the existing research results,this paper proposes a new tape of rocking column with buckling-restrained longitudinal reinforcement,which is a new kind of rocking column formed by using the buckling-restrained longitudinal reinforcement instead of the ordinary steel bar in the traditional reinforced concrete column and relaxing the constraint of the column and the foundation,and the corresponding resilience model is proposed and verified through analysis.A new tape of buckling-restrained longitudinal reinforcement is proposed and the monotonic compression test and numerical simulation of the buckling-restrained device were carried on.The restraining function of the buckling-restrained device was verified.The buckling deformation process of restrained buckling longitudinal reinforcement and the effects of the reinforcement diameter and the space between the buckling-restrained device and the reinforcement on its hysteresis function were studied.The numerical simulation of the column were carried on,and the effects of the reinforcement diameter and the axial compression ratio on the hysteretic behavior were studied.The results show that the hysteresis curve of the rocking column with buckling-restrained longitudinal reinforcement is a typical flag type,and its strength is the superposition of the strength of the rocking column and the longitudinal reinforcement.The rock of the column occurs after the longitudinal reinforcement yields.A rational design can make the structure not rock in the small earthquake stage,and rock in the middle earthquake stage when the longitudinal reinforcement buckling occurs.Also,the increase of the axial compression ratio and the reinforcement diameter can increase the lateral bearing capacity of the rocking column with bucklingrestrained longitudinal reinforcement.