Building retrofit prior to damaging earthquakes: reduction of residual capacity and repair costs

When a seismic event occurs, damage may accumulate in a building affecting its capacity to withstand future earthquakes. This study investigates, by means of a detailed case study, the advantages related to the application of structural retrofit prior of earthquake events in terms of structural safety variation due to damage. The response of an existing non -ductile RC frame in Califor nia is simulated using a refined finite element model that properly accounts for possible brittle failures of structural members. Furthermore, the actual structural capacity is evaluated accounting for typical collapse modes that can affect the behavior of non -ductile buildings. Different retrofit strategies have been adopted and damaging earthquake scenarios considered. The future seismic performances of retrofitted structure before damage are compared with the case in which no mitigation strategies have b een adopted showing the advantages of different categories of intervention for different earthquake scenarios.