Wave protection structures

Wave defences are structures designed to protect a harbor or part of a harbor (water level, breakwater) against wave action (direct attack, crossing, submersion, erosion, etc.).

Some of these structures can also be used to protect isolated facilities or structures (water intakes, sea outfalls) or even stretches of coastline.

These are man-made structures, with the exception of natural structures, which may have the same functions.

Some of these structures may be located inside the harbor, to improve or complete wave protection: inner piers, counter-piers, embankments or damping beaches.

Traditionally, these works can be classified into :

• dikes, breakwaters or jetties, which are subdivided into :

  • embankment dikes, generally built with natural or artificial (concrete) riprap;

  • Vertical dikes with wave-exposed walls that may or may not be permeable;

• special structures used under specific conditions. These include

  • the fixed water wall ;

  • the oscillating wall of water ;

  • floating breakwaters ;

  • Pre-fermentation structures ;

  • synthetic seaweed mats ;

  • air bubble curtains.

  Until now, the cost (investment and operation) / efficiency ratio of these last two types of structure has been too unfavorable for widespread use.