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This paper evaluates the overstrength, ductility, and response modification factors for low to mid-rise buckling restrained braced frames (BRBFs) designed as per the 2010 National Building Code of Canada. In addition to nonlinear static pushover analyses, dynamic time history analyses are performed to assess the seismic performance of four-, six-, and eight-story BRBFs. Different bracing configurations, including chevron (inverted-V) and split-X braces, are considered for the building frames with varied frame span lengths of 6 m and 8 m. The results confirm that the prescribed design values for overstrength and ductility factors provide reasonable estimations of the lower bound for these factors. The response modification factor obtained in this study ranged from 4.8 to 6 for different frames. The results also indicate that the response modification factor decreases with the increase of story height and span length. Moreover, bracing configurations may slightly affect the response modification factor for BRBFs. [ABSTRACT FROM AUTHOR]

This paper presents an assessment of the seismic performance of a ductile concrete core wall used as a seismic force resisting system for a 12-storey concrete office building in Montréal, designed according to the 2005 National building code of Canada (NBCC) and the 2004 Canadian Standards Association standard A23.3. The core wall consists of a cantilever wall system in one direction and a coupled wall system in the orthogonal direction. The building is analyzed in the nonlinear regime. The main conclusion from this work is that the capacity design shear envelope for the studied wall structure largely underestimates that predicted, primarily in the cantilever wall direction, and this in turn significantly increases the risk of shear failure. This issue is essentially due to (i) an underestimation by the new NBCC spectral response acceleration of the higher mode responses of a reinforced concrete wall structure whose seismic response is dominated by higher modes; and (ii) a deficiency in the capacity design method in estimating the wall shear demand on such walls, even when their behavior is lightly inelastic. [ABSTRACT FROM AUTHOR]

Design guidelines for laterally loaded light-gauge steel-frame – wood structural panel shear walls are not available in Canadian codes. A design method for the calculation of shear stiffness and strength has been developed for use with the 2005 National Building Code of Canada (NBCC), however. This method was based on the analysis, using an equivalent energy elastic–plastic (EEEP) approach, of over 180 single-storey shear wall tests of various configurations. Ductility-related (Rd) and overstrength-related (Ro) force modification factors also need to be defined to calculate equivalent static seismic forces following the 2005 NBCC. This paper describes the development of these two factors based on the EEEP analysis of the shear wall test results. To verify the "test-based" Rd and Ro values, nonlinear time-history dynamic analyses of two representative buildings were carried out using a suite of 10 earthquake records scaled to the 2% in 50 year uniform hazard spectrum (UHS) for Vancouver, British Columbia. Preliminary values have been determined for the force modification factors, namely Rd = 2.5 and Ro = 1.7. [ABSTRACT FROM AUTHOR]