Background to Some of the Seismic Design Provisions of the 2010 National Building Code of Canada

摘要

The seismic design provisions of the National Building Code of Canada (NBCC) underwent significant changes between 1995 and 2005. The changes proposed for the seismic requirements of 2010 NBCC are, in comparison, limited in scope as well as in their extent. The background to some of the changes introduced in 20101 NBCC or in the Commentary to the Code is presented. The changes discussed here include: site effect factors, upper limit on the design forces as determined from static or dynamic analysis, a new minimum value for the design spectral acceleration values for concrete shear wall structures, adjustments in some values of the higher mode effect factors and overturning moment reduction factors, P-Delta effects and the design provisions based on dynamic analysis. The changes and revisions have been discussed in relation to the provisions of 2005 NBCC.