Assessment of earthquake-induced damage in Quebec city, Canada

A methodology is developed for first-order assessment of the seismic risk involving seismic hazard, local building inventory, and evaluation of respective vulnerability. Central to the vulnerability analysis is the concept of fragility functions used to determine the probability of exceedance of a specified damage state, where the nonlinear structural behaviour is defined by capacity curves. A new set of continuous hazard-compatible fragility functions is proposed for rapid risk assessment on urban and regional scales in interactive spreadsheet application. To demonstrate the method, it was applied in a dense urban environment of downtown Quebec City, Canada, for damage assessment of low-rise wood light frame and unreinforced brick masonry buildings. Earthquake scenario with M6.2 and distance 10 km from the centroid of the study area was developed from deaggregation of the seismic hazard defined by the current National Building Code of Canada-NBCC 2010. The ground shaking was represented with a simplified site-specific response spectrum, fully defined with spectral accelerations at 0.3 and 1.0 s. The results show that as much as 61% of the considered buildings would sustain certain degree of damage. The influence of epistemic uncertainties in the ground motion prediction and the site-class on damage estimation is evaluated.