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Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper describes the seismic behaviour of chevron steel braced frames for 2-, 4-, 8-, and 12-storey steel building structures. Two different design approaches were considered: one that corresponds to current CSA-S16.1 seismic provisions for braced frames with nominal ductility with an R factor of 2.0, and one in which the beams are sized to develop a fraction of the yield tension capacity of the bracing members. In this second approach, an R factor of 3.0 was used for determining the seismic loads and chevron bracing with stronger beams capable of developing 100%, 80%, and 60% of the brace yield load were examined. The results show that current S16.1 provisions for chevron braced frames may lead to systems that are prone to dynamic instability for 4-storey and taller structures. Chevron bracing with stronger beams exhibits a more stable inelastic response and can be used for structures up to 8 storeys in height. For 2- and 4-storey buildings, chevron braced frames with beams designed to develop only 60% of the brace yield resistance can be used. The analyses also show that the force demand in brace connections, beams, and columns as determined from capacity design provisions agree well with that anticipated under strong ground motions.Key words: earthquakes, seismic design, steel, structures, braced frames, bracing members, beams, columns, connections.Cet article décrit le comportement sismique de contreventements en treillis avec diagonales en chevron utilisés dans la charpente d'acier de bâtiments de 2, 4, 8 et 12 étages. Deux approches de conception ont été considérées : l'une qui suit les dispositions actuelles de la norme CSA S16.1 pour les contreventements à ductilité nominale et l'autre où les poutres sont conçues pour résister aux efforts engendrés lorsque l'effort dans la diagonale tendue atteint une fraction de sa limite élastique. Pour la seconde méthode, on a considéré un coefficient R égal à 3,0 pour le calcul des charges sismiques et on a étudié des contreventements dont les poutres pouvaient reprendre des efforts correspondant à un effort dans les diagonales tendues égal à 100%, 80% et 60% de leur limite élastique. Les résultats montrent que les contreventements de 4 étages et plus peuvent subir de grandes déformations latérales et être sujets à une instabilité dynamique lorsque conçus selon la norme S16.1 actuelle. Les contreventements avec poutres pouvant soutenir la plastification des diagonales tendues ont un comportement plus stable et peuvent être utilisés dans des structures jusqu'à 8 étages. Pour des bâtiments de 2 et 4 étages, on peut utiliser des poutres conçues pour un effort dans les diagonales tendues égal à 60% de leur résistance plastique. Les analyses dynamiques démontrent également que les efforts dans les assemblages des diagonales, dans les poutres et dans les poteaux tels, qu'obtenus d'un calcul par capacité, correspondent bien aux efforts que l'on peut anticiper lors d'un séisme important.Mots clés : séismes, conception parasismique, acier, structures, contreventements en treillis, diagonales, poutres, poteaux, assemblages. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)