PSI - Issue 57

Jacques BERTHELLEMY et al. / Procedia Structural Integrity 57 (2024) 872–903 J. Berthellemy / Structural Integrity Procedia 00 (2023) 000 – 000

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transitions for girders with limited spans. W. Hoorpah notes in [23] that he was in the contractual obligation to justify the cope hole detail in Fig. 8 according to the 71 MPa class category.

Fig. 7: Wrong and right conception for the A1 overpass. The box solution was actually built in Avignon. The centralbox girder solution was considered impossible by the local administration,but could be built shortly after at an other place facing a similar problem in Avignon. Nowadays, cope holes, which coincide with a thickness transition, are rightly avoided in motorway bridges. However, the 2010 "Guide for long-lasting Steel Bridges" [24] still presents cope holes and the use of various types of stiffeners fox bottom flanges of boxes as if they were a good design option. After the construction of the bridge presented in [23] several bridges were built in France with cope holes. The Stress Concentration Factors SCF presented in [19] helps today for the best rational fatigue assessment of existing motorway bridges presenting features similar to those presented in Fig. 8 that were wrongly calculated during the '90s. The shear force has to be considered to achieve fatigue categorising of the cope hole detail in the flange. The use of the von Mises invariant calculated by Code_Aster as a scalar value for the fatigue resistance evaluation allows a better reliability of the results compared to the use of the dominant principal stress, since the consideration of the shear force locally makes the problem a multi-axial fatigue problem.