Data-driven operation and maintenance of the Normandy and Tancarville long-span bridges

With main spans of 608m and 856m respectively, Pont de Tancarville and Pont de Normandie are the longest suspension and cable-stayed bridges in France. Both bridges are managed by CCI Seine Estuaire, with a concession granted until 2031. Pont de Tancarville was opened to traffic in 1959 at which time it was the longest suspended bridge in Europe. The composite deck comprises a Robinson slab with stiffening truss girders. The main suspension cables and hangers were replaced in 1999 after the failure of 1 out of 120 strands was discovered. Pont de Normandie was built in the late 1990s, to enhance the connection between the Le Havre, the second largest French harbour, and the western coastal area. Opened in 1995, it was once the world longest cable stayed bridge and drove a technological leap in bridge construction.COWI and Setec tpi are currently assisting CCI with investigative and diagnostic activities on the two bridges, focusing on suspension systems, articulation, and the concrete structures. This work makes use of extensive, but targeted, structural health monitoring combined with an understanding of the structural systems to investigate the performance of key structural elements. The present paper describes the main activities being undertaken to enable CCI to plan corrective and preventive measures to extend the design lives of the structures and to ensure a safe passage for the users of both bridges.