The seismic vulnerability and rehabilitation of reinforced concrete (RC) buildings originally designed for gravity loads have drawn increasing attention over the past decades. Stepped buildings with soft-story irregularities, typically lacking seismic considerations, often show significant weaknesses due to sudden stiffness reductions and inadequate capacity design. This study examines the effectiveness of a retrofitting strategy involving a pure- bending yielding dissipater system to improve seismic performance in such structures. Three RC frame models (5- , 9-, and 13-story) with both regular and irregular configurations (setbacks, soft-story conditions) were analyzed using the Endurance Time (ET) method under Design Spectrum (DS) and Maximum Expected (ME) hazard levels. The results indicate that retrofitted frames reduced peak inter-story drifts by approximately 40–60 % compared to unretrofitted cases, limiting drifts to 1.5 % (DS) and 2.1 % (ME) in 5-story frames and preventing collapse under ME-level excitations. Retrofitted configurations also demonstrated up to a 60 % reduction in the maximum inter-story column damage value (MICDV) at soft-story levels. Moreover, damage across all stories remained within repairable thresholds (MICDV < 0.7), effectively controlling the distribution of structural damage. The retrofitted frames resisted seismic intensities 1.5–2 times greater before collapsing, supporting the effectiveness of the yielding dissipater system in balancing axial forces and redistributing stiffness.
