The influence of the thermal expansion of beams on the structural behaviour of columns in steel-framed structures during a fire

In the UK, new design guidance is currently being developed for the behavio ur of steel-framed buildings when subjected to fire. This is primarily base d on recent research that considers the structural behaviour of all horizon tal members, without applied fire protection, acting as a complete entity w ithin the building. This guidance assumes that columns designed to current design procedures will always be adequate when used within this new design philosophy. For bare steel columns these existing design methods usually co nsist of applying some form of passive fire protection. Presented in this paper is an analytical investigation of the structural be haviour of columns when subjected to various structural and fire scenarios. The results from this study do not endorse the view that current fire desi gn methods for columns are adequate. These design methods will require revi sion if instability of columns during a fire is to be avoided. In most case s this will result in the need for additional passive fire protection to be applied to the steel columns. (C) 2000 Published by Elsevier Science Ltd. All rights reserved.