Application Of Buckling-restrained Braces On Concrete Frame Structural Seismic Retrofitting

In recent years, the reinforcement technology of energy dissipation is widelyapplied in the project of seismic retrofitting. A quantity of energy dissipationdevice are placed in the key parts of the structure, in the frequent earthquake, thedevice can enhance the rigidity of the structure, in the rare earthquake, the energydissipation device can yield before other main members, which will reduce theearthquake response of the structure. Buckling restrained brace is goodperformance energy dissipation device, it differs from ordinary steel brace.Buckling restrained brace can yield in tension and compression condition, thus,Buckling restrained brace has excellent hysteretic behavior.The research background of this paper is National Primary and Middle SchoolSeismic Retrofitting Engineering. This paper introduce the principle andengineering application of the buckling restrained brace. six concrete framestructural models are established and analysised by the finite element softwareETABS9.2, which is on the basis of the theory of seismic analysis, including elasticand elastic-plastic analysis. Elastic analysis adopts response spectrum analysis,elastic-plastic analysis adopts push-over analysis. From the results of analysis,when subjected to the frequent earthquake, the BRB are still in elastic state, andmay provide stiffness for the structure, when subjected to the moderate and rareearthquake, BRB are taking the lead in yielding state, providing reliability forsafety of the structure. In addition, the analysis of every examples show that the topbraces do not yield, through the comparison of the developing sequence of plastichinge and structural performance point before and after removing the top brace, wecan find that the top braces are not significant, they can be unset.