Practical case with regard to applying the functional and environmental method to low crest level, detached breakwaters

The research work as presented in this article covers the design of detached breakwaters since they constitute a type of coastal defence work with which to combat many of the erosion problems found on beaches in a stable, sustainable fashion. The main aim of this work is to formulate a functional and environmental (but not structural) design method, enabling the fundamental characteristics of a detached breakwater to be defined as a function of the effect it is wished to induce on the coast, and taking into account variables of a different nature (climate, geomorphology and geometry) influencing the changes the shoreline undergoes after its construction. With this article, it is intended to submit the final result of the investigation undertaken, applying the detached breakwater design method as developed to solving a practical case. Thus it may be shown how the method enables a detached breakwater’s geometric pre-sizing to be tackled at a place on the coast with certain climate, geomorphology and littoral dynamic characteristics, first setting the final state of equilibrium it is wanted to obtain therein after its construction.

Functional and environmental design of detached, low crest level breakwaters

In this article we research the design of detached breakwaters, a type of coastal defence work designed to combat erosion on beaches in a stable, sustainable fashion. Our aim is to formulate a functional and environmental (nonstructural) method of design that defines the fundamental characteristics of a detached breakwater as a function of the desired effect on the coast whilst meeting social demands and preserving or improving the quality of the littoral environment. We aim to make this method generally applicable by considering relations between variables of different natures (climatic, geomorphologic, and geometric) influencing the changes experienced on the coast after the detached breakwater has been built. We carried out the study of the relations between the different variables on the data from 19 actual, existing detached breakwaters on the Spanish Mediterranean coastline, and we followed a methodology based on the implementation of nondimensional monomials and on a search for relations of dependency between them. Finally, we discussed the results obtained and came up with a proposal for a design method that uses some of the graphic relations found between the variables studied and that achieves the main objective. For example, a case of a detached breakwater’s geometric presizing is solved as a practical demonstration of how the method is applied. La investigación que se presenta en este artículo aborda el diseño de los diques exentos, por constituir estos un tipo de obras de defensa costera con el que poder luchar de una forma estable y sostenible contra muchos de los problemas de erosión que existen en las playas. El objetivo principal de este trabajo es la formulación de un método de diseño funcional y ambiental (no estructural) que permita definir las características fundamentales de un dique exento en función del efecto que se quiera inducir en la costa, satisfaciendo las demandas sociales y preservando o mejorando la calidad del medio ambiente litoral. Además, se busca la aplicabilidad general del método mediante la consideración de relaciones entre variables de distinta naturaleza (climáticas, geomorfológicas y geométricas) que tienen influencia en los cambios que se experimentan en la costa tras la construcción del dique exento. El estudio de las relaciones entre las distintas variables se realiza sobre los datos de una base de diecinueve diques exentos reales, existentes en el litoral mediterráneo español, y sigue una metodología basada en el planteamiento de monomios adimensionales y en la búsqueda de relaciones de dependencia entre ellos. Finalmente, la discusión de los resultados obtenidos conduce a la propuesta de un método de diseño que utiliza algunas de las relaciones graficas encontradas entre las variables estudiadas y con el que se consigue el objetivo principal anteriormente expuesto. Para demostrar la aplicación práctica del método se resuelve un caso de predimensionamiento geométrico de un dique exento a modo de ejemplo.