2D And 3D Physical Model Testing For The Rehabilitation On The Frioul Port Breakwater (France)

Abstract

A white archipelago anchored in the Mediterranean Sea 2 km off the coast of Marseille (France), the port of Frioul is made up of the Pomègues islands (to the south) and Ratonneau (to the north). It is protected on the west side by the Berry breakwater (renovated in 1984), and on the east side by the Condorcet breakwater (figure 1.a). The port was built in the early 1820s (Berry breakwater) to take care of the quarantine of ships coming from areas infected by yellow fever, then developed in the 1850s (Condorcet breakwater in the East) to make it a military port.

The current findings highlight that the eastern breakwater is seriously damaged and must be rehabilitated (figure 1.b). Accordingly, the rehabilitation solution, which consists to replace the actual rock armour unit, was physically modelled, and tested for its hydraulic stability and the overtopping performance as well as the forces and pressures acting on the crown wall. The process includes recreation of breakwater cross sections in a 2D wave flume at a scale of 1:35 (figure 2.a), and a optimized breakwater configuration proposed in a 3D wave basin at a scale of 1:50 (figure 2.b).

These two campaigns made it possible to compare and optimize the design, first with the state of the art (Van Gent, M., et van der Werf, I., 2019) (Mares-Nasarre and van Gent, M., 2020), then with the observations and measurements collected from the modeling.