Research On Buckling-Restrained Brace And Application In Structural Seismic Design

This paper takes the actual project of outpatient building in a county hospital as the research background,and discusses the design method of setting BRB to satisfy the requirements of current seismic fortification target of key projects.such as hospitals,primary schools and so on.In the preliminary structural design of the project,The bottom columns appears overreinforced and the most story drift angle exceeds the limit of earthquake resistant design code.By applying the BRB in the original structure to improve its lateral stiffness and to meet the requirements of rare occurrence earthquake?We can analysis the original frame structure and BRB-structure by using the finite element software with the response spectrum analysis and time history analysis under the frequent earthquakes and Pushover analysis and elasto-plastic time history analysis under rare occurrence earthquake.On the basis of applying BRB,to explore the effect of seismic behavior under the frequent earthquake and the effect of energy dissipation under rare occurrence earthquake.The results show that BRB can effectively reduce the displacement response of the structure and the horizontal seismic effect of the original overreinforced column under frequent earthquake and solve the problem of overreinforced.Under the rare occurrence earthquakes,BRB can dissipate energy with resistanting to buckle before the main frame structure yield,which will reduce the seismic response of the structure.The time curve of column shear force in the BRB-frame is smaller than that of the pure frame structure by contrasting the original design frame and the BRB-frame under the action of rare occurrence earthquake,which indicates that although the addition of BRB will cause the structural base shear to become larger,the seismic action of the bottom column in the structure is obviously reduced.Through the energy dissipation design of the hospital outpatient building,it is shown that BRB can effectively solve the problem that the most story drift angle of the frame is not satisfied and the overreinforced of the bottom columns.Through the energy dissipation design of structure with the rational arrangement of BRB,which provides a reference to design the similar structure.