Important landfill work underway for the future Portier Cove district

An important element of the Portier Cove land extension project is the technical platform landfill (RTPT), which ensures that the caissons are held in place. It forms a 500 metre by 9.5 metre band at the back of the caissons and rises 175 metres above the surface of the sea. The pebbles that compose it are between 20 and 180 millimetres and come from the Revest-les-Eaux quarry in the Var region of France.

The pebbles are transported by two boats, the Rhine and the Daniel Bernouilli, the latter of which can self-unload.

The 10,000-ton caissons are installed on the carefully prepared backfill, then ballasted with the quarried materials to ensure they are stable and can stand up to violent storms. Rocks are used to protect the sea-facing side. The production and positioning of the RTPT will continue until the end of August.

The RTPT is flattened by machinery every day, like the caisson backfill, will be vibro compacted. The largest dredger in the world, the 220-metre-long Leiv Eiriksson, will make approximately 11 round trips to carry the 420,000m3 of Sicilian sand that will fill the platform. Once the ring of caissons is blocked in position and filled with sand, the water around the project will be pumped out to make way for the platform. At the same time the Leiv Eiriksson will fill the platform with the sand.