1st International Conference on Natural Hazards & Infrastructure 28-30 June,2016, Chania, Greece
Seismic microzonation and vulnerability assessment of buildings and critical infrastructure: A case study of Québec City, Canada M.-J. Nollet1, A. Abo El Ezz, A. Khaled École de technologie supérieure, Université du Québec, Montréal, Canada
D. LeBoeuf Université Laval, Québec, Canada
M. Nastev Geological Survey of Canada, Natural Resources Canada, Québec, Canada
ABSTRACT Strong earthquakes in Eastern Canada with major urban centers founded partially by soft postglacial sediments have high damage potential. The presented seismic microzonation for Québec City was conducted in agreement with the provisions of the National building Code of Canada based on the available geological, geomorphological and topographical knowledge and existing boreholes logs, completed by geophysical and ambient vibration measurements. To identify the most vulnerable infrastructure particular attention was paid to the city-owned buildings (105) and bridges (119). Structural properties were integrated with local geological and geotechnical data within a user-friendly GIS system to provide Québec City decision makers and engineers with powerful quantitative and visual representation of potentially high risk facilities. For the seismic risk assessment at an urban scale, several seismic scenarios were generated with typical moment magnitude (M) vs. rupture distance (R) combinations (e.g., M6.0-R10km, M7.0-R30 km) obtained from the deaggregation of the seismic hazard. The inventory of assets at risk consisting of more than 16,000 buildings was developed using sidewalk and virtual desktop survey techniques, and by interpretation of municipal property assessment databases through inference matrices. The vulnerability was determined using fragility data correlating directly to the ground shaking intensity to five damage states: none, low, moderate, extensive complete. Keywords: mirozonation, vulnerability, infrastructures, rapid assessment
INTRODUCTION Eastern Canada is characterized by a low to moderate seismicity. However, several significant earthquakes with magnitudes between 6 and 7 have occurred in the past and triggered significant ground and structural failures. Most of major urban centers, such as Québec City, are located in the St. Lawrence Valley and are founded partially on soft quaternary sediments. Strong earthquake events have thus the potential to cause severe damages far from the epicentral zone. The 1988M6.0 Saguenay earthquake is the strongest event in Eastern North America within the last 60 years. The total felt area was over 3.5 million km2 (Cajka and Drysdale 1996). Geotechnical and structural damages observed outside the epicentral area, e.g. Québec City 1
Corresponding Author: M.-J. Nollet, École de technologie supérieure, Univ. du Québec, Montréal, Canada,
[email protected]
