This paper describes the proposed changes to the 2005 edition of the National Building Code of Canada related to the force modification factors. A description of the ductility-and overstrength-related force modification factors is given. The selection of the values proposed for these two factors for the various seismic force resistance systems is given in light of the design and detailing provisions that are specified in the Canadian Standards Association standards for steel, concrete, timber, and masonry building structures.Résumé : Cet article décrit les changements proposés à l'édition 2005 du Code National du Bâtiment du Canada (CNBC) concernant les facteurs de modification de force. Une description des facteurs de modification de force reliés à la ductilité et reliés à la sur-résistance est donnée. La sélection des valeurs proposées pour ces deux facteurs pour les différents systèmes de résistance des forces sismiques est donnée en lumière des dispositions de conception et des épu-res spécifiées dans les normes CSA pour l'acier, le béton, le bois et les structures en maçonnerie.

Results from monotonic and quasi-static cyclic tests on connections used in heavy timber construction are presented for two types of fasteners: steel bolts and glulam rivets. Bolted connections with three different diameter bolts, arranged in several configurations, as well as two different configurations of glulam rivet connections were tested. All configurations included a main glulam member and two steel side plates. For bolted connections, the seismic behaviour was found to be primarily dependent on the bolt slenderness ratio. Bolted connections with higher slenderness ratios (smaller diameter bolts) exhibited more ductile behaviour with considerable steel yielding and wood crushing before failure. Glulam riveted connections, which were designed in rivet failure mode, showed superior seismic performance when compared to bolted connections for similar design load levels. Riveted connections were also able to dissipate the highest amount of input energy before the failure was reached.Key words: timber connections, glulam rivets, bolts, ductility, timber, wood, braced frames, seismic performance, heavy timber construction.

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The 1994 edition of CSA (Canadian Standards Association) Standard 086.1 "Engineering design in wood" includes, for the first time, specified strength and stiffness for design rated oriented strandboard (OSB). Design rated OSB panels are manufactured in accordance with the new CSA Standard 0452. In this paper, the results of the short-term (1–10 min) test data which led to the establishment of the three rating grades of Type 1 (standard) design rated OSB are presented. In addition, factors that may affect the classification such as panel thickness and orientation are discussed. Key words: OSB, waferboard, structural panels, wood.