Evaluating the functional recovery performance of modern residential tall reinforced concrete shear wall buildings in Metro Vancouver

Modern tall residential Reinforced Concrete Shear Wall (RCSW) buildings in Metro Vancouver are exposed to a considerable hazard due to the proximity of various seismic sources, such as the Cascadia Subduction Zone (CSZ), and the presence of Georgia sedimentary basin, which can amplify the intensity of ground motions at medium-to-long periods. Current building codes do not account for basin amplification effects, they intend to ensure life-safety in extreme earthquakes and do not explicitly minimize damage to building components that preserve building functionality. This study aims to provide insights into the expected loss and functional recovery time of tall RCSW buildings in Metro Vancouver under a variety of earthquake intensities. To this end, nonlinear models of archetype RCSW buildings are developed for eight different locations in Metro Vancouver. These models are subjected to ground motions representative of a range of hazard levels as per Canada’s 2015 National Seismic Hazard Model, which neglects basin effects, as well as a suite of simulated ground motions of M9 CSZ earthquake scenarios, which explicitly accounts for basin amplification. The structural responses are employed to conduct a loss assessment using a well-established methodology and a downtime assessment using a recently developed framework. Loss estimates show that the mean loss ratios under the M9 motions vary between 1.4% and 32% across Metro Vancouver and range from 0.7% to 14% for the range of hazard levels considered in this study. Downtime estimates show that the functional recovery time of buildings subjected to the M9 motions can range from 175 to 543 days and vary between 164 to 491 days for the range of hazard levels considered. The archetype buildings do not meet the robustness criteria of ensuring that there is a probability of less than 10% of not achieving sheltering capacity under the functional level earthquake (~ 475 year return period). Similarly, the archetype buildings do not meet the rapidity criteria of observing less than a 10% probability of not achieving functional recovery within four months after the functional level earthquake. Downtime deaggregation shows that the main contributor to functional recovery time is attributed to slab-column connection damage.Applied Science, Faculty ofCivil Engineering, Department ofGraduat