Collapse of steel bridges during construction can occur as a result of a global buckling behaviour which may be overlooked when using member resistance checks such as those in the Eurocodes. Furthermore, buckling can require careful study when working with existing structures that were not constructed to modern tolerances and which consequently cannot be safely assessed using modern design codes. It is an issue of design, construction and sustainability. This paper describes how finite element analysis can be used to predict buckling modes. It draws on recommendations in the recently published NCHRP Report 725 [1], exploring the problem of global buckling modes and considering how to identify when these should be of concern to the designer. Use of FE analysis in the determination of member resistances is also discussed, with reference to current design standards and to alternative approaches which may be appropriate for historical structures, drawing out the key considerations and necessary checks when undertaking such analyses.

steel bridges; buckling; construction; finite element analysis