PERFORMANCE-BASED RETROFIT GUIDELINES FOR LOW-RISE SCHOOL BUILDINGS IN BRITISH COLUMBIA, CANADA

摘要

In 2004, the Province of British Columbia, on the West Coast of Canada, announced an ambitious 10-15 year,$1.5 billion seismic retrofit program for the province's 750 at-risk schools. The purpose of this earthquake preparedness initiative is to accelerate the upgrading of school public safety in the moderate and high seismicity regions of the province. Given the magnitude of the mitigation program, the Ministry of Education and Western Economic Diversification Canada made a commitment to support the development of state-of-the-art performance-based seismic engineering technology for achieving optimum safety within a cost-effective mitigation framework, which could not be achieved based on best current practice.This paper describes one component of this technical development program, the formulation of performance-based structural assessment and retrofit design guidelines. This paper also describes some current areas of study such as the selection of a more representative suite of ground motions for the province and the nonlinear response analysis of soft sites The guidelines include seventeen different types lateral deformation resisting systems found in low-rise construction. They provide minimum lateral strength requirements to achieve different levels of drift. The guidelines have procedures to allow engineers to combine different structural systems, and to account for existing materials that are typically discounted in current practice.Non-linear dynamic analysis was used to predict the response of the prototype models, which represent the generic response of a given type of low-rise construction. Ground motions records were scaled to match the seismic demands specified in the 2005 National Building Code of Canada.