Choice of steel material for bridge bearings to avoid brittle fracture : background documents in support to the implementation, harmonization and further development of the Eurocodes ; joint report

Bridge bearings need verification against brittle failure at low temperatures. The design of bearings according to EN 1337 may lead to structural components with thicknesses no longer covered in the relevant technical construction regulations. Due to its specific geometry, the loading and stressing and the fabrication process the prerequisites for using the rules in EN 1993-1-10 lead to conservative restrictions or uneconomical choice of steel material. For an economical bearing design further modifications of the existing rules are necessary. This report adapts the fracture mechanical approach used in EN 1993-1-10 and gives information for a ''safe-sided'' choice of steel material for bearings. The main modifications refer to the hypothetical design crack scenario and the definition of the ''nominal design stress'' at the geometric ''hot-spot''. An advanced methodology using Finite Elements and a simplified method using linear bending theory are evaluated.