Fatigue assessment due to non-standard detailing of orthotropic bridge decks

Anđelko Vlašić, Nijaz Mujkanović, Gordana Hrelja Kovačević

Last modified: 2019-03-04

Abstract


Modern norms define design guidelines for designers and contractors regarding acceptable detailing and manufacturing of bridge orthotropic deck plates. The convenience of these design guidelines is that for most deck elements, a specified detail can be accepted without additional fatigue verification. Consequently, these details were used in the design documentation of the Mainland - Čiovo Island Bridge in Trogir. But, in one of the steel workshops, during orthotropic deck manufacturing, considerable discrepancies from design detailing were noticed. These discrepancies comprise additional spacer plates placed between the rib and the deck plate to simplify the welding process, which largely influences fatigue resistance. To approve these changes and to allow for the finished orthotropic deck to be used in the bridge superstructure, additional fatigue assessment was performed. This paper shows the numerical model used for attaining stress ranges in the rib to deck welds, and the fatigue assessment according to HRN EN 1993-1-9. Ultimately, fatigue verification passed, and manufactured deck was approved. But, nevertheless the detailing used in the manufacturing process was abandoned for all further deck segments, and it is not to be recommended for use.

Keywords


orthotropic bridge deck, fatigue, detailing, welding, numerical model

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