A Discussion on some Key Issues for Seismic Design of Concentrically Braced Frames According to Canadian and Chinese Codes

Abstract

To gain further insight into the seismic design of concentrically braced frames as defined by the Canadian and Chinese codes, a comparison of the main design requirements contained in each code is carried out in this paper. The comparison emphasizes on the differences existing in these two code provisions, and the reasons behind them. The issues that are examined include the seismic force resisting systems for braced frames, the height restrictions, the force transferred to the beams in chevron configurations, the slenderness ratios of the bracing members, the width-to-thickness ratios of the brace sections, and the influence of brace connections on the columns. Some additional issues that still remain undefined on the seismic response of these systems and some proposals for further studies are also discussed. It is concluded through this comparison that a number of modifications are still required in order to fully implement a capacity design approach of these systems in both codes.