The Research And Application Of Buckling-Restrained Braces In An Office Building

Since the Wenchuan and Yushu earthquakes,the earthquake has become a major natural disaster that harms society.The state has paid more attention to the safety of concrete buildings in earthquakes,and has successively increased the seismic fortification intensity in some areas of the country,resulting in a large number of office buildings that do not meet the seismic fortification requirements.Using buckling restrained brace to reinforce such structures can increase the structural rigidity,increase the structural ductility,and increase the energy dissipation capacity of the structure.Therefore,it is favored by the industry.Therefore,it is of great significance and value to study the buckling restrained brace for the reinforcement mode of office buildings and the seismic performance of reinforced structures.In this paper,with the background of the specific project of seismic fortification intensity enhancement in a region,SAP2000 is used to analyze the response spectrum analysis under the multi-event earthquake,and the nonlinear time history analysis and Pushover analysis under rare earthquakes are analyzed,and with the structure reinforced by the concentrically steel brace for comparison.The following conclusions have been drawn:(1)In the response spectrum analysis under multi-event earthquakes,both the buckling restrained brace and the concentrically steel brace can significantly reduce the cycle time of the structure and the displacement angle between the layers.Because the concentrically steel brace's section is larger,it can provide more rigidity.The structural performance of the concentrically steel brace reinforcement is slightly better than that of the buckling restrained brace reinforcement structure.(2)Under the action of rare earthquakes,due to the excessive rigidity of the concentrically steel brace,the impact of the earthquake action is amplified,so that the buckling occurs prematurely and the work is discontinued.The buckling restrained brace can consume energy earlier to protect the main structure,therefore,is significantly superior to the concentrically steel brace in reducing displacement and energy consumption of the structure.(3)In Pushover analysis,under the two lateral loading conditions,the data obtained by the inverted triangle lateral loading mode is closer to the data in the time history analysis,which can better simulate the rare earthquakes on the structure.The impact,at the same time,verifies the feasibility of using Pushover analysis to quickly assess the seismic performance of office buildings.(4)The development of the structural plastic hinge under Pushover analysis shows that the buckling restrained brace improves the structural load transmission and makes the force of the component more reasonable.Through the study of this paper,the performance advantages of the buckling restrained brace compared with the concentrically steel brace in the seismic reinforcement are clarified,and the reinforcement mode of the buckling restrained brace has important reference value for designing such office building.