The welded junctions in the structure of the bridge: Rules, comparisons, applied examples

The note, moving from the recent emanation of the Italian DM 14.01.08 "Norme tecniche per le costruzioni" (Technical standards for constructions), compares the verification criteria of the welded joints, particularly the fillet welded joints. In addition to the recent Italian legislation, it will show the results following the criteria of the Instructions of the Italian CNR (National Research Council) and the criteria of the Eurocode 3 Part 1-8 titled "Design of joints". While the Instructions CNR require the higher minimum height of the throat, the Eurocode 3 prescribes the lower throat. In particular, the Eurocode allows to adopt the "Directional method" or the "Simplified method". The latter provides a value substantially less than the first. The DM 14.01.08 gives results which values are between the previous two, in fact the Ministerial Decree takes in part the Method 1 of the Eurocode 3, allows to adopt the semplified method and introduces a third Method which provides the same result of the Instructions CNR. From a constructive point of view, the differences of the design results may affect the production processes, in fact, for example, to ensure the minimum fillet weld, from a single pass procedure to a multipass could significantly increase the global welding time.