Frédéric Brunet’s research is in the field of seismic design of steel structures. New seismic design provisions for heavy industrial steel building structures that have been implemented in the S16-14 Annex M. The main objective of the research is to improve and simplify the design requirements for columns that are part of two orthogonal braced frames. Research conducted last year at Polytechnique indicated that those requirements are probably overly conservative, may be conflicting and their application may pose problems. In addition, height limits currently specified in Annex M may still prevent the application to Annex M to tall industrial structures such as those containing elevated vessels. A second main objective of the study by Frédéric will be to examine the possibility of extending current height limits for braced steel frames.
Both objectives will be achieved by examining the seismic response of typical 3D industrial buildings having different heights and levels of complexity. In all cases, the structures studied will include braced frames in both directions with columns part of orthogonal frames. Prototype structures will be defined starting from examples to be provided by Canadian engineering consultants. Frédéric will design the frames in accordance with current Annex M requirements except that different strategies will be applied for the columns. Nonlinear analysis will be performed to verify the behaviour of the system and identify the most promising column design approach in terms of performance and cost. The analyses will be performed using detailed 3D models to accurately reproduce inelastic brace response as well as column flexural buckling. The influence of the height on the braced frame response will also be carefully investigated to determine ranges of heights for which the design methods are applicable.
It is expected that this work will lead towards improvements in future editions of CSA S16 Annex M.