Evaluation of the Seismic Retrofitting of Mainshock-Damaged Reinforced Concrete Frame Structure Using Steel Braces with Soft Steel Dampers

Most reinforced concrete (RC) frames would exhibit different degrees of damage after mainshock excitations, and these mainshock-damaged RC (MD-RC) are highly vulnerable to severe or even complete collapse under aftershock excitations. In the present study, effectiveness utilizing soft steel damper (SSD) as a passive energy dissipation device for seismic retrofitting MD-RC frame actions was investigated. A common three-story in rural area employed numerical evaluation framework analysis also proposed. Based on proposed framework, nonlinear dynamic time history with without schemes conducted evaluate retrofit effect frame. The results revealed that could effectively improve natural vibration characteristics frame, especially first-order frequency maximum increase nearly four times. pulse-like aftershocks is better than non-pulse-like minor slightly damage. addition, only bottom story might cause aggravate structural