The application of new seismic provisions of CSA S16-09 for the design of columns in two-panel steel concentrically braced frames (CBFs) is investigated. In these provisions, in-plane bending moments resulting from frame inelastic deformations and notional out-of-plane transverse loading must be considered for the design of the columns. A design example is presented. Emphasis is put on the selection of the critical panel based on the probable resistance of the bracing members and the design of the columns for in-plane and out-of-plane stability. An alternative design approach is studied where a higher force modification factor is considered for the calculation of the seismic loads. Static and dynamic nonlinear analyses are used to assess the seismic performance of the different frame designs. Additionally, the influence of parameters such as the frame height, frame height ratio, frame width, the building location, and the force modification factor are investigated. The anticipated storey drift and panel drift demands appear to be acceptable. Column bending moment values used in design are found to be realistic for in-plan bending and conservative for out-of-plane bending. A higher force modification factor could represent a feasible alternative to current provisions for two-panel CBFs.
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