An urban resilience assessment framework based on macroscopic analysis of seismic city performance

This study presents a comprehensive framework for evaluating seismic resilience of old Reinforced Concrete (RC) buildings using YouSimulator, an urban earthquake platform enabling macroscopic modeling and analysis of large-scale building regions through nonlinear time-history analysis. The framework estimates resilience curves by calculating key post-earthquake metrics: building damage states, repair/retrofitting costs, workforce demand, Construction & Demolition Waste (CDW), recovery time and CO 2 emissions, providing a holistic measure of urban vulnerability and post-retrofit gains. It was applied to 1,252 old RC buildings in central Thessaloniki, Greece, under three earthquake scenarios (frequent, design, and rare). Frequent earthquakes cause minor structural damage but high repair costs, reducing functionality (load-bearing capacity) by 11.9% with two-year recovery and 1,500 workers; post-repair functionality improvement is negligible (0.3%). Design-level earthquakes cause major damage without collapse, reducing functionality by 26.6%, with repair and retrofitting costs averaging 22.4% of replacement value, about five-year recovery and 2,500 workers; retrofitting improves functionality slightly (11.9%). In extreme cases, CDW reaches 290,698 tons, generating 57,558 tons of CO₂. Rare earthquakes cause catastrophic losses (>50% functionality), collapses, and recovery exceeding 12 years with 2,500 workers. CDW management becomes critical, averaging 537,680 tons and about 21.8 months for disposal, with peaks at 936,364 tons generating 185,400 tons of CO₂, comparable to the 2023 Turkey-Syria earthquake. Post-repair and retrofitting can increase city’s functionality up to 46.5% over pre-event conditions. The framework provides a robust tool for citywide seismic assessment, enabling decision-makers to identify vulnerable buildings, evaluate resilience, allocate resources and strengthen urban preparedness.