Study On Seismic Behavior Of Reinforced Concrete Frame With Few Buckling-Restrained Braces

The reinforced concrete frame structures has the features of flexible arrangement and good economic benefit,and it is a main structural system in the construction engineering.The frame structure is a kind of flexible structure with good yielding mechanism,which can be deformed and dissipated under the action of rare earthquake.But when the height of the structure is too high,the section needs to be set very large,in order to meet the requirements of normal use,not economic enough.Adding few buckling-restrained braces to the frame structure can significantly increase the structural stiffness,increase the redundancy of the structure and reduce the construction budget in the meantime.It is a relatively good structural system for the construction.In this paper,buckling-restrained braces are arranged in a pure frame structure near the height limit in 7 degree zone(0.10g)to form a frame structure with few braces.The seismic parameters of the two structures are simulated and compared by elastic-plastic analysis.The difference of seismic performance between the two structures is studied.The results show that braces can be arranged in the frame structure.Effectively increase the bearing capacity and lateral stiffness of the structure,braces help the frame share the seismic shear force,reduce the section size and reinforcement area,improve the safety affluence and anti-collapse ability of the structure,and achieve the dual purposes of safety,applicability and economic rationality.There are a large number of old existing frame structures in China.Because of the different design and construction ages,the seismic capacity can not meet the requirements of the current seismic design code.Potential collapse hazards in the event of destructive earthquakes.The seismic construction measures are difficult to meet the current seismic code standards.The traditional reinforcement methods such as the method of increasing section,the method of outsourcing steel and the method of pasting steel plate,etc.,have many problems,such as wet operation in the construction site,many construction procedures,long construction period,great influence on the later use of the building and the environment.Taking the teaching building of a three-story frame structure in a middle school in Beijing as an example,this paper adopts the overall seismic reinforcement method of placing buckling-restrained braces in the frame,which can solve the problems of insufficient reinforcement area and axial compression ratio of the frame column of the existing building,as well as the problem of insufficient lateral stiffness of the existing building,and effectively control the structural deformation.It is proved that the method of setting a few buckling restrained braces can effectively improve the seismic capacity of frame structures,especially the collapse resistance.