Multicriteria and Multilevel Framework for Seismic Risk Management of Existing Buildings in Canada

A multicriteria and multilevel seismic risk management framework is presented to ensure an acceptable and consistent level of risk for existing buildings in Canada with a focus on minimizing threats to life safety. The framework consists of three levels: (1) Level 1: preliminary seismic-risk screening tool (PST); (2) Level 2: semiquantitative seismic-risk screening tool (SQST); and (3) Level 3: seismic evaluation guidelines (SEG). Level 1 (PST) was developed based on a number of key criteria (seismicity, benchmark code edition, consequences of failure, and remaining occupancy time) to assist in exempting existing buildings from further assessment without the need for a site visit. Level 2 (SQST) consists of three key components: (1) structural scoring system that quantitatively assesses the structural seismic risk based on the probability of collapse; (2) nonstructural components scoring system that qualitatively evaluates the seismic risk of nonstructural components based on the seismic demand of critical nonstructural components; and (3) ranking procedure that prioritizes buildings with potentially unacceptable seismic risk for the Level 3 (SEG) based on structural and nonstructural components priority indices. The Level 3 (SEG) aims to identify the building deficiencies that lead to unacceptable seismic risk for existing buildings.