Enhancing the Seismic Resilience of Canada's Built Environment through Comprehensive Risk-Based Assessments of New and Existing Tall Buildings

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Studies on the impacts of likely earthquake scenarios in the Canadian West and East Coasts suggest that direct financial losses can exceed $70 billion and $60 billion, respectively. These losses, primarily due to seismic damage to buildings and infrastructure, highlight the need for our built environment to be more resilient to earthquakes. One of the primary objectives of building codes is to provide acceptable safety in extreme earthquakes. However, significant building damage is considered acceptable as long as the life-safety objective is met. As a result, both existing and newly designed buildings are susceptible to damage from strong earthquakes, which could result in extensive downtime and potential need for demolition and reconstruction. This research program aims to enhance the seismic resilience of Canada's built environment by improving our understanding of the seismic risks posed by new and existing tall buildings, which play a key role in our socio-economic activity and their resilience is vital to ensuring effective post-earthquake recovery of our cities. While many cities in Canada recognize their seismic vulnerability, programs to improve their resilience are often challenged by a lack of understanding of the expected seismic performance of their building stock or the costs associated with adopting different strategies. This research program aims to enable seismic policy decision-making with explicit consideration of the societal and economic impacts of the performance of the built environment during major earthquakes. The long-term objectives are to develop new methodological approaches to assess seismic risk in buildings and their implications on urban resilience. These will be achieved by focusing on short-term structural engineering aspects related to tall buildings, which are required to develop earthquake disaster resilience: (1) advance the quality and accuracy of urban risk models by developing tools and data specific to the tall building stock in Canada; (2) quantify costs and benefits of performance-based seismic design of future tall buildings; and (3) develop seismic resilience indicators to advise design decisions related to future buildings, promoting more resilient construction. The results from Objective 1 will serve to evaluate different retrofit interventions in seismically vulnerable existing tall buildings to cost-effectively mitigate their risk; results which will be distilled to inform seismic policy. Objectives 2 and 3 will highlight whether the implicit life-safety objective of building codes is sufficient to ensure the seismic resilience of cities and will inform discussions by the Standing Committee on Earthquake Design of the National Building Code of Canada related to enhanced seismic performance objectives and performance-based design requirements for future construction. This program will also provide state-of-the-art training to future members of Canada's earthquake engineering community.