Seismic Response of RC Frames with a Soft First Story Retrofitted with Hysteretic Dampers under Near-Fault Earthquakes

Reinforced concrete (RC) frame structures with open first stories and masonry infill walls at the upper are very common in seismic areas. Under strong earthquakes, most of energy dissipation demand imposed by earthquake concentrates story, this eventually leads building to collapse. A efficient cost-effective solution for upgrading type structure consists installing hysteretic dampers story. This paper investigates response RC soft-story frames retrofitted subjected near-fault ground motions terms maximum displacements lateral forces compares them those obtained far-field earthquakes. It is found that similar levels total input energy, story caused earthquakes about 1.3 times larger than under while inter-story drift distribution values scarcely affected. concluded can be easily predicted from balance using appropriate parameter reflects influence impulsivity motion: so-called equivalent number cycles.