Floating Breakwaters Combined with Sheet Piles for the Protection of San Marco Square in Venice, Italy

Moderate flooding of the San Marco Square in Venice, Italy, occurs during high tide even if the Modulo Sperimentale Elettromeccanico, or Mo.S.E., is in operation. The guaranteed safeguard threshold is close to the square quay elevation; hence, overflow onto the square can be prevented, but flooding may still occur as a result of wave overtopping. This paper numerically evaluates the design wave conditions for the barrier to be placed in front of the quay and experimentally evaluates its wave attenuation efficiency. The proposed barrier is a combination of sheet piles and floating breakwaters, and it meets the technical, environmental, and architectural constraints that preserve the area’s inestimable historical and cultural value.