scholarly journals SEAWARD PROFILE FOR RUBBLE MOUND BREAKWATERS

1964 ◽  
Vol 1 (9) ◽  
pp. 35 ◽  
Author(s):  
Melville S. Priest ◽  
Joel W. Pugh ◽  
Rameshwar Singh
Keyword(s):  
Shallow Water ◽  
Water Waves ◽  
Structural Damage ◽  
Rational Design ◽  
Normal Incidence ◽  
Wave Action ◽  
Design Procedures ◽  
Rubble Mound ◽  
Spilling Breakers ◽  
Rubble Mound Breakwaters

For several years, some coastal engineers have been aware that the seaward face of rubble mound breakwaters of the common trapezoidal cross-section is conducive to relatively severe wave action and possible damage to the breakwaters. Further, it has been suggested that a preferable seaward profile would be that composed of three straight lines, with the middle line at a relatively small angle with the horizontal, to form what might be thought of as abroad berm. In order to arrive at a more realistic knowledge of seaward profiles for which wave intensity and likelihood of breakwater damage are minimal, a laboratory study of shallow-water wave action on rubble breakwaters was initiated at Auburn University, It is hoped that such knowledge will lead to design procedures which will result in (a) less violent wave action, (b) less structural damage, and (c) the possible use of smaller stones. Thus far, the study has been devoted to shallow-water waves of two types, steep, smooth waves and spilling breakers, acting, with normal incidence, upon breakwaters constructed of various materials and having an initial seaward slope of 1 on if. For each set of conditions, the stable seaward profile was determined. Through dimensional analysis and curve fitting, an effort was made to describe the stable seaward profiles in terms of physical quantities which influence the profiles. It is the authors1 belief that the results of this study will be useful in leading to more rational design procedures.

scholarly journals Dynamic Calculation of Breakwater Crown Walls under Wave Action: Influence of Soil Mechanics and Shape of the Loading State

Water ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1149
Author(s):  
Enrique Maciñeira ◽  
Enrique Peña ◽  
José Sande ◽  
Andrés Figuero
Keyword(s):  
Time Domain ◽  
Soil Mechanics ◽  
Soil Characteristics ◽  
Wave Action ◽  
Dynamic Calculation ◽  
Simplified Method ◽  
Static Calculation ◽  
Rubble Mound ◽  
The Time Domain ◽  
Rubble Mound Breakwaters

As a consequence of the action of waves on rubble mound breakwaters, there are loads—both on the vertical and horizontal sides of the crown walls—which modify the conditions of their stability. These loads provoke dynamic impulses that generate movements that are not possible to be analyzed by static calculation. This study presents the results obtained using a simplified method of dynamic calculation of the crown walls, presented in Appendix A, based on the variation of the forces acting against the structure in the time domain and the soil characteristics. It provides results of the expected movements of the structure and the deformations produced in the foundation. With this, traditional static calculation is improved and knowledge about the phenomenon is enhanced, highlighting the uncertainties in the system.

scholarly journals ON 3-DIMENSIONAL STABILITY OF RESHAPING BREAKWATERS

1988 ◽  
Vol 1 (21) ◽  
pp. 169 ◽  
Author(s):  
H.F. Burcharth ◽  
Peter Frigaard
Keyword(s):  
Large Volume ◽  
Dimensional Stability ◽  
Wave Action ◽  
Rock Material ◽  
3 Dimensional ◽  
Specialized Equipment ◽  
Rubble Mound ◽  
Rubble Mound Breakwaters

The paper deals with the 3-dimensional stability of the type of rubble mound breakwaters where reshaping of the mound due to wave action is foreseen in the design. Such breakwaters are commonly named sacrificial types and berm types. The latter is due to the relatively large volume of armour stones placed in a seaward berm. However, as also conventional armoured breakwaters sometimes do contain a berm it is assumed that a better and more ambiguous designation would be "reshaping" mound breakwaters. The principle of reshaping breakwaters is to use relatively fine rock material which will then be eroded to S-shape profiles if sufficient amount of material is provided, Fig. 1. This type of breakwater can be constructed and maintained without the use of expensive specialized equipment. For a detailed discussion see Baird et al., 1984.

Discussion of “Irregular Wave Action on Rubble-Mound Breakwaters”

1972 ◽  
Vol 98 (1) ◽  
pp. 110-118
Author(s):  
Juan B. Font ◽  
Jade Dattatri ◽  
Per M. Bruun ◽  
Palmi Johannesson
Keyword(s):  
Wave Action ◽  
Irregular Wave ◽  
Rubble Mound ◽  
Rubble Mound Breakwaters

Artificial Intelligence and Rubble-Mound Breakwater Stability

2012 ◽  
pp. 1499-1506
Author(s):  
Gregorio Iglesias Rodriguez ◽  
Alberte Castro Ponte ◽  
Rodrigo Carballo Sanchez ◽  
Miguel Ángel Losada Rodriguez
Keyword(s):  
Physical Model ◽  
Model Tests ◽  
Wave Action ◽  
Ann Model ◽  
Climate Conditions ◽  
Wave Flume ◽  
Physical Model Tests ◽  
Rubble Mound ◽  
The Stability ◽  
Rubble Mound Breakwaters

Breakwaters are coastal structures constructed to shelter a harbour basin from waves. There are two main types: rubble-mound breakwaters, consisting of various layers of stones or concrete pieces of different sizes (weights), making up a porous mound; and vertical breakwaters, impermeable and monolythic, habitually composed of concrete caissons. This article deals with rubble-mound breakwaters. A typical rubble-mound breakwater consists of an armour layer, a filter layer and a core. For the breakwater to be stable, the armour layer units (stones or concrete pieces) must not be removed by wave action. Stability is basically achieved by weight. Certain types of concrete pieces are capable of achieving a high degree of interlocking, which contributes to stability by impeding the removal of a single unit. The forces that an armour unit must withstand under wave action depend on the hydrodynamics on the breakwater slope, which are extremely complex due to wave breaking and the porous nature of the structure. A detailed description of the flow has not been achieved until now, and it is unclear whether it will be in the future in view of the turbulent phenomena involved. Therefore the instantaneous force exerted on an armour unit is not, at least for the time being, amenable to determination by means of a numerical model of the flow. For this reason, empirical formulations are used in rubble-mound design, calibrated on the basis of laboratory tests of model structures. However, these formulations cannot take into account all the aspects affecting the stability, mainly because the inherent complexity of the problem does not lend itself to a simple treatment. Consequently the empirical formulations are used as a predesign tool, and physical model tests in a wave flume of the particular design in question under the pertinent sea climate conditions are de rigueur, except for minor structures. The physical model tests naturally integrate all the complexity of the problem. Their drawback lies in that they are expensive and time consuming. In this article, Artificial Neural Networks are trained and tested with the results of stability tests carried out on a model breakwater. They are shown to reproduce very closely the behaviour of the physical model in the wave flume. Thus an ANN model, if trained and tested with sufficient data, may be used in lieu of the physical model tests. A virtual laboratory of this kind will save time and money with respect to the conventional procedure.

HYDRO-GEOTECHNICAL STABILITY OF RUBBLE MOUND BREAKWATERS UNDER WAVE ACTION

2013 ◽  
Author(s):  
Clemente Cantelmo ◽  
Scott Dunn ◽  
Giovarmi Cuomo ◽  
William Allsop
Keyword(s):  
Wave Action ◽  
Geotechnical Stability ◽  
Rubble Mound ◽  
Rubble Mound Breakwaters

scholarly journals DESTRUCTION CRITERIA FOR RUBBLE-MOUND BREAKWATERS

1968 ◽  
Vol 1 (11) ◽  
pp. 49 ◽  
Author(s):  
Adelkis J. Rogan
Keyword(s):  
General Purpose ◽  
Wave Action ◽  
The Other ◽  
Periodic Waves ◽  
Cover Layer ◽  
Storm Duration ◽  
Equilibrium Profile ◽  
Rubble Mound ◽  
The One ◽  
Rubble Mound Breakwaters

The general purpose of the author's research undertaken in the "Laboratoxre National d'Hydraulique" was to study wave action on rubble-mound breakwaters with regular (periodic) waves on the one hand and irregular (random) wind generated waves on the other, and to compare the effects of these two types of waves by use of the storm duration t. With a first series of periodic waves experiments we have obtained the destruction of the breakwater's cover-layer for different storm durations t, by varying H and T. The mass of armor units remained constant. The angle of the slope, according to the seaward equilibrium profile could be considered as constant.

Artificial Intelligence and Rubble-Mound Breakwater Stability

2011 ◽  
pp. 144-150
Author(s):  
Gregorio Iglesias Rodriguez ◽  
Alberte Castro Ponte ◽  
Rodrigo Carballo Sanchez ◽  
Miguel Ángel Losada Rodriguez
Keyword(s):  
Physical Model ◽  
Model Tests ◽  
Wave Action ◽  
Ann Model ◽  
Climate Conditions ◽  
Wave Flume ◽  
Physical Model Tests ◽  
Rubble Mound ◽  
The Stability ◽  
Rubble Mound Breakwaters

Breakwaters are coastal structures constructed to shelter a harbour basin from waves. There are two main types: rubble-mound breakwaters, consisting of various layers of stones or concrete pieces of different sizes (weights), making up a porous mound; and vertical breakwaters, impermeable and monolythic, habitually composed of concrete caissons. This article deals with rubble-mound breakwaters. A typical rubble-mound breakwater consists of an armour layer, a filter layer and a core. For the breakwater to be stable, the armour layer units (stones or concrete pieces) must not be removed by wave action. Stability is basically achieved by weight. Certain types of concrete pieces are capable of achieving a high degree of interlocking, which contributes to stability by impeding the removal of a single unit. The forces that an armour unit must withstand under wave action depend on the hydrodynamics on the breakwater slope, which are extremely complex due to wave breaking and the porous nature of the structure. A detailed description of the flow has not been achieved until now, and it is unclear whether it will be in the future in view of the turbulent phenomena involved. Therefore the instantaneous force exerted on an armour unit is not, at least for the time being, amenable to determination by means of a numerical model of the flow. For this reason, empirical formulations are used in rubble-mound design, calibrated on the basis of laboratory tests of model structures. However, these formulations cannot take into account all the aspects affecting the stability, mainly because the inherent complexity of the problem does not lend itself to a simple treatment. Consequently the empirical formulations are used as a predesign tool, and physical model tests in a wave flume of the particular design in question under the pertinent sea climate conditions are de rigueur, except for minor structures. The physical model tests naturally integrate all the complexity of the problem. Their drawback lies in that they are expensive and time consuming. In this article, Artificial Neural Networks are trained and tested with the results of stability tests carried out on a model breakwater. They are shown to reproduce very closely the behaviour of the physical model in the wave flume. Thus an ANN model, if trained and tested with sufficient data, may be used in lieu of the physical model tests. A virtual laboratory of this kind will save time and money with respect to the conventional procedure.

scholarly journals STABILITY OF RUBBLE MOUND BREAKWATERS IN SHALLOW WATER AND SURF ZONE : AN EXPERIMENTAL STUDY

2012 ◽  
Vol 1 (33) ◽  
pp. 85
Author(s):  
Guirec Prevot ◽  
Olivier Boucher ◽  
Maryline Luck ◽  
Michel Benoit
Keyword(s):  
Shallow Water ◽  
Wave Height ◽  
Significant Wave Height ◽  
Characteristic Wave ◽  
Significant Wave ◽  
Wave Parameters ◽  
Rubble Mound ◽  
Wave Conditions ◽  
Wave Models ◽  
Rubble Mound Breakwaters

Rubble-mound breakwaters are often pre-designed with empirical formulae allowing the estimation of armour stone size or weight, taking into account the wave conditions (mainly a characteristic wave height and a characteristic period), the type and density of stone or block used, the slope of the mound, the acceptable level of damage, etc. In deep water conditions, the existing formulas are rather well established (e.g. Hudson and Van der Meer formulas among others). They use as input data wave parameters that are well defined (e.g. the significant wave height H1/3 or sometimes the height H1/10) and easily accessible, from in situ measurements or from numerical wave models. In shallow water however, and in particular in breaking wave conditions (where most of the small breakwaters are built), a number of physical processes (refraction, shoaling and breaking) significantly modify the incoming waves. They also lead to changes in the wave height distribution (which can no longer be regarded as being of Rayleightype) and in the shape of the wave spectrum. This, combined with the fact that most of the models used nowadays for nearshore wave propagation are spectral wave models (e.g. SWAN, TOMAWAC, etc.) and thus provide spectral parameters as output (typically the spectral significant wave height Hm0 and the peak period Tp or the mean energetic period Tm-1,0) has raised the question of which characteristic wave parameter should be used in stability formulas for rubble-mound breakwaters in shallow water. This has led to the consideration of more representative wave parameters such as H2% or Tm-1,0 which are sometimes less accessible from existing wave database or numerical modelling studies. The objective of the present study is to review and compare several available methods to calculate armour stone weight in shallow waters, and to provide some insight into the applicability and limitations of these methods based on a series of wave flume experiments.

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