Performance-based seismic retrofitting and resilience assessment for RC buildings considering direct and indirect losses

The intense forces imposed by earthquakes on structures can cause significant structural and non-structural losses if not properly planned and managed. It has been revealed that retrofitting structures constructed before the adoption of modern building codes can effectively reduce losses and mitigate earthquake impacts. This paper proposes a framework to quantify the effects of seismic retrofit solutions on: the global response of the structure, component-level damages (structural and non-structural components), loss estimation (including direct losses, based on economic-, social-, and environmental-losses, and indirect losses based on downtime), and resilience quantification (based on functionality loss and recovery model). This study focuses exclusively on retrofitting ground story columns and proved very effective when column capacities primarily control the structural behavior. The social, environmental, and indirect losses are converted into monetary value by using the value of statistical life (VSL), carbon pricing (CP), and relocation/rental price approaches, respectively. These are then incorporated into economic losses to compute total losses as a single value, aligning with the monetary factors prioritized by the funding agencies, insurance companies, and loan granting institutes. The resilience index is determined and the effectiveness of various retrofit alternatives is evaluated. A five-story reinforced concrete building is used as an example, and the methodology is applied. The results indicate that incorporating indirect losses and non-structural damage is crucial for risk and resilience assessments.