application of steel braced structures with controlled rocking system in seismic retrofitting of buildings, case study of a university building

Preventing collapse of structures is one of the targets of conventional seismic design. although many of buildings after a severe earthquake maintain the life safety performance level, operation of the buildings usually will be impossible due to existence of damages and permanent drifts. rehabilitation of such buildings has large economic costs as well as long downtime. in the past two decades, researchers have introduced new seismic systems that are known as self-centering systems. these systems in addition to dissipating energy and mitigating structural damage reduce permanent drifts after earthquake. in this case study, the application and efficiency of a self-centering system is evaluated as a retrofit strategy for a building at shahid beheshti university in tehran, iran. in this research, three methods of retrofitting with external truss structure including controlled rocking on foundation with and without fuses and piles at foundation have been compared. using nonlinear time history analyses in two earthquake hazard levels, assessment of plastic hinges, horizontal acceleration of stories, base shear as response parameters corresponding to structural and nonstructural damages have been done. the results show the proper performance of the controlled rocking system to improve response parameters including structural performance levels and its applicability as an alternative retrofitting approach.