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.

Overtopping of harbour breakwaters: a comparison of semi-empirical equations, neural networks, and physical model tests

This paper reports extensive tests of empirical equations developed by different authors for harbour breakwater overtopping. First, the existing equations are compiled and evaluated as tools for estimating the overtopping rates on sloping and vertical breakwaters. These equations are then tested using the data obtained in a number of laboratory studies performed in the Centre for Harbours and Coastal Studies of the CEDEX, Spain. It was found that the recommended application ranges of the empirical equations typically deviate from those revealed in the experimental tests. In addition, a neural network model developed within the European CLASH Project is tested. The wind effects on overtopping are also assessed using a reduced scale physical model

An annotated bibliography on detached breakwaters and artificial headlands /

Includes indexes.

Field experiences with floating breakwaters in the eastern United States /

In the past 10 years, the use of floating breakwaters as temporary coastal structures has become increasingly widespread in the United States as an inexpensive means for suppressing waves. However, as with any new technology, there have been many failures and a substantial number of imaginative, successful innovations. One of the chief problems contributing to the failure rate has been a lack of awareness by designers of reliable, up-to-date technical information. As part of a large research effort to remedy this problem, a survey was conducted on field experience with floating breakwaters in the Eastern United States. Results of the survey confirmed that state-of-the-art technical literature is not being properly disseminated. Structures built according to early design manuals were shown to have failed before the completion of their design life. Conversely, floating breakwaters built to the standards set by recent research have fared well and show promise of meeting their design golas. The weakest areas of the present technology are flotation and the anchoring systems. It is recommended that a concentrated research effort be directed toward these problem areas; it is also recommended that the monitoring of state-of-the-art projects continue. (Author).

Monitoring completed coastal projects : operational assessment of floating breakwaters, Puget Sound, Washington /

"April 1988."

Santo Domingo kitchen-midden and burial mound /

"Bibliographical notes": p. 137.

Side-scan sonar investigation of breakwaters at Calumet and Burns Harbors on southern Lake Michigan /

"December 1987."

Estimation of wave transmission coefficients for permeable breakwaters /

"October 1979."

Ecological effects of rubble weir jetty construction at Murrells Inlet, South Carolina /

"June 1984"--Pt. 2.