Seismic resilience of typical code-conforming RC moment frame buildings in Canada

Abstract

This article examines the baseline resilience of reinforced concrete (RC) moment frame buildings conforming to the seismic design standards of Canada. Metrics for robustness, rapidity, and resilience are evaluated to capture the system’s reliability, speed of recovery, and socioeconomic impacts. Buildings of different heights are evaluated using nonlinear time-history analyses. Six damage states are defined as disjoint branches of an event tree depending on the building’s path to recovery. For a scenario earthquake of magnitude 7.3 magnitude at a distance of 30 km from Vancouver, the housing occupancy recovery trajectory is developed. Monte Carlo simulations are used to propagate uncertainty from seismic hazards to the building response to the lead time required for recovery. Buildings are found to maintain 50%–65% of their pre-event housing occupancy in the immediate aftermath. The housing occupancy is restored to 90% within 2–4 months, with a shorter recovery period for low-rise buildings, whereas the system resilience level requires 6 months to 1 year for restoration to 90%. Empirical data from the Loma Prieta (1989) and Northridge (1994) earthquakes are used to compare analytically predicted repair times. The findings from this article will facilitate the shift to resilience-based design in Canada.