Earthquake resistance of high rise reinforced concrete structures with buckling restrained braces

Buckling restrained brace is relatively new type of structural bracing system and includes a steel core confined within a steel hollow section by a grout infill material. This bracing system utilizes the ductility of the steel more effectively than conventional one. In this study, the earthquake response of the high-rise reinforced concrete (RC) frame structures with buckling-restrained braces were investigated. For this, two RC structures having 9 and 18 stories were taken into account as a case study. The effect of using buckling-restrained braces to protect the structures against earthquakes was studied. As a bracing pattern, diagonal shape buckling-restrained braces were utilized over the height of the RC frames. The nonlinear dynamic time-history analysis was performed on the RC frame structures before and after inclusion of buckling-restrained braces. Different ground motion records, namely, 1999 Chi Chi, 1999, Hector Mine, and 1999 Düzce, were used in the analysis. It was concluded that the use of buckling-restrained braces over the frame height was found to have a significant effect on the seismic behavior of the structures. Buckling-restrained bracing cases exhibited lower displacement and more uniform inter-story drift demands compared to the cases without buckling restrained braces. Keywords: Buckling restrained brace, Earthquake, Nonlinear analysis, Reinforced concrete structure, Seismic upgrading.