How are precast concrete caissons used to build quay walls?

To build quay walls using precast concrete caissons, the structures are first constructed on land and then floated into their designated position. Once in place, they are sunk onto a prepared bed on the sea bottom.12

This method is typically employed in locations where the depth to the dredged bottom is not excessive and the material used for reclamation possesses good self-supporting qualities, such as in the Mediterranean where minimal tidal variation reduces the required depth. Engineers must carefully design these caissons to withstand the lateral thrust of the material retained behind the wall, which is specifically selected for stability.2

Once the caissons are positioned and sunk, they form the basic structure of the wall. A final superstructure is then added above the highest tide level to accommodate necessary dockside services, such as crane tracks and other operational requirements.2