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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Due to the geometry, the fatigue class along the cut is strongly reduced, from 125 MPa to about 40 or 50 MPa, according to the radius of the local cut, by considering the stress concentration factor with the same method also used to evaluate the cope holes in the present article. This class is coherent with the traffic on the motorway and the elapsed time between construction in 1989 and apparition of the cracks in 2014. Twenty different locations also presented cracks of type 2 during the inspection of October 2015. Had the motorway company not followed the annualinspection recommendation, the collapse of the bridge would probably not have been avoided.

3. Using of finite elements analysis with the fatigue “hot spot method” to develop new features 3.1 CL Connexion evaluated regarding fatigue

An evaluation regarding fatigue was achieved in 2009 in order to design the clothoïdal CL shape of steel-concrete connection dowels [11,12,13,14] now introduced in future Eurocode 4.

Figure 12 : Probability of crack initiation during a reference loading cycle

A first application was built in France in 2016. Two existing old concrete bridges in Marseille could not support carrying the envisaged 7m high acoustic protection walls. The road authorities in charge of the A7 highway and project manager decided, to design independent box bridges to carry the walls. Those bridges presented on Figure 13 are made up of a steel beam with spans of 22m and a totalwall height of 6,5m exposed to the wind and located not very far from the sea shore. The CL connection makes the connection to the concrete possible avoiding a very dense plantation of studs. More details can be found in [25].