A breakwater –also called a seawall if people can pass through it- is designed to reduce the intensity of coastal waves or other adverse weather phenomena. They can range from large structures to provide harbor shelter, to small ones to protect a promenade adjacent to a beach.
The basic design consists of building a mountain or dune by accumulating material of different sizes, with a submerged part and an emerged part on which an element in the form of a block or wall called a shoulder is sometimes placed . A large part of the waves breaks over the submerged area and loses strength; the rest of the energy follows and collides with the emergence.
The large rocks or concrete blocks on the outside of the structure absorb most of the shock and protect the core, usually a smaller accumulation of material.
There are many types of breakwaters according to their construction typology and their purpose . It can be continuous, in the form of a single uninterrupted barrier; or multiple, with several groynes positioned with gaps between them.
The distance between each gap is chosen based on the wavelengths of the dominant swell, among other characteristics. Likewise, they can be fixed or floating, and waterproof or permeable to allow the transfer of sediments towards the coast.
