Improving response of low-rise asymmetric buildings with self-centering controlled rocking steel braced-frames through proper plan distribution of strength

Self-centering controlled rocking steel braced-frame (SC-CR SBF) is an innovative seismic resistant system that reduces structural earthquake damages compared with conventional structural systems. In addition, the self-centering behaviour could reduce or eliminate building residual deformation and simplify the required repair after an earthquake. These benefits make this system an ideal alternative for conventional lateral force resisting systems such as moment-resisting frames or shear walls. Along with this issue, asymmetric structures are more vulnerable to earthquake excitations and require special seismic design considerations. Therefore, in this study, it is tried to improve the seismic behaviour of asymmetric SC-CR-SBF systems with proper distribution of strength. In this regard, the behaviour of low-rise uni-directional mass asymmetric SC-CR-SBF buildings is studied under bi-directional horizontal ground motions using OpenSEES software. The results show that the appropriate distribution of the strength of SC-CR SBFs in the plan reduced adverse torsional effects and based on these distributions, the proper configuration of mass and strength centers is introduced. Finally based on the results with appropriate arrangement of the centers, the maximum drift of the asymmetric structure decreases as much as roughly 14%. In other words, the maximum drift of the asymmetric SC-CR-SBF buildings of this study are acceptably close to the symmetric case.