scholarly journals STABILITY FORMULA FOR TETRAPOD INCORPORATING SLOPE EFFECT

2012 ◽  
Vol 1 (33) ◽  
pp. 39
Author(s):  
Kyung-Duck Suh ◽  
Jin-Sung Kang
Keyword(s):  
Hydraulic Model ◽  
Model Tests ◽  
Test Results ◽  
Reasonable Accuracy ◽  
Rubble Mound ◽  
Wave Conditions ◽  
Rubble Mound Breakwaters ◽  
Packing Densities

To develop a stability formula for Tetrapods armoring rubble mound breakwaters, sixty hydraulic model tests have been conducted for various wave conditions and slope angles of breakwaters. The test results are used, along with the data of previous researchers, to develop a new stability formula. The developed formula is proven to be applicable to breakwaters with various slope angles with reasonable accuracy. It is also shown to be applicable to low-crested breakwaters and different packing densities, if the corresponding terms are incorporated in the formula. The uncertainty of the proposed formula is also given.

scholarly journals WAVE OVERTOPPING ON RUBBLE MOUND BREAKWATERS

1988 ◽  
Vol 1 (21) ◽  
pp. 57 ◽  
Author(s):  
Pierliugi Aminti ◽  
Leopoldo Franco
Keyword(s):  
Hydraulic Model ◽  
Model Tests ◽  
Geometric Parameters ◽  
Random Wave ◽  
Wave Overtopping ◽  
Wave Flume ◽  
Rubble Mound ◽  
Rubble Mound Breakwaters

The paper gives the results of an extensive series of hydraulic model tests carried out in a random wave flume, in order to study the effects on wave overtopping of the main geometric parameters of a typical rubble mound breakwater with crown wall. The results have been compared with those from other studies and analyzed with different methods. Generalized design diagrams and formulae for the prediction of overtopping discharges are finally given for a large number of popular breakwater configurations.

scholarly journals WAVE OVERTOPPING AT BERM BREAKWATERS IN LINE WITH EUROTOP

2012 ◽  
Vol 1 (33) ◽  
pp. 12 ◽  
Author(s):  
Sigurdur Sigurdarson ◽  
Jentsje W. Van der Meer
Keyword(s):  
Hydraulic Model ◽  
Model Tests ◽  
Wave Period ◽  
Wave Steepness ◽  
Wave Overtopping ◽  
Rubble Mound ◽  
Rubble Mound Breakwaters

The paper presents the development of a new overtopping formula for berm breakwaters. Overtopping data from hydraulic model tests of berm breakwaters have been gathered and reanalysed in line with the procedure in the EurOtop Manual. The data shows a clear dependency on wave period or wave steepness, which is in contrast to the main conclusion of the CLASH project and the EurOtop Manual for conventional rubble mound breakwaters. The formula is roughly validated on prototype performance.

scholarly journals Correction: Eldrup, M.R., et al. Stability of Rubble Mound Breakwaters—A Study of the Notional Permeability Factor, based on Physical Model Tests. Water 2019, 11, 934

Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2483
Author(s):  
Mads Røge Eldrup ◽  
Thomas Lykke Andersen ◽  
Hans Falk Burcharth
Keyword(s):  
Physical Model ◽  
Model Tests ◽  
Permeability Factor ◽  
Physical Model Tests ◽  
Rubble Mound ◽  
Rubble Mound Breakwaters

The authors wish to make the following corrections to this paper [...]

scholarly journals Effects of vertical wall and tetrapod weights on wave overtopping in rubble mound breakwaters under irregular wave conditions

2014 ◽  
Vol 6 (4) ◽  
pp. 947-964 ◽  
Author(s):  
Sang Kil Park ◽  
Asgar Ahadpour Dodaran ◽  
Chong Soo Han ◽  
Mohammad Ebrahim Meshkati Shahmirzadi
Keyword(s):  
Vertical Wall ◽  
Wave Overtopping ◽  
Irregular Wave ◽  
Rubble Mound ◽  
Wave Conditions ◽  
Rubble Mound Breakwaters

scholarly journals TOE BERM DESIGN FOR RUBBLE-MOUND BREAKWATERS: EXAMPLE OF THE SAFI POWER PLANT PROJECT

2017 ◽  
pp. 34
Author(s):  
COUTOSTHEVENOT Marie ◽  
HONG Kyung-Wook
Keyword(s):  
Power Plant ◽  
Physical Model ◽  
Design Feature ◽  
Breaking Waves ◽  
Model Tests ◽  
Construction Methods ◽  
Physical Model Tests ◽  
Rubble Mound ◽  
Hydraulics Laboratory ◽  
Rubble Mound Breakwaters

DAEWOO E&C (Engineering & Construction) is in charge constructing a new 1320 MW coal-fired power plant located approximately 15 km south-west of the city of Safi in Morocco. ARTELIA Eau & Environnement was appointed by the Contractor to perform the hydraulic design review of the rubble-mound breakwaters protecting the intake and outfall. The toe berm is a key design feature of rubble-mound breakwaters built in breaking conditions, since it helps to support the armour layer and protect the structure from potential scour-induced damage. The initial toe berm design was based on Van Der Meer’s empirical formula (1998). Due to the very shallow water conditions, the toe design was verified through physical model tests (2D and 3D) in ARTELIA’s hydraulics laboratory located in Pont-de-Claix, near Grenoble (France). The physical model tests demonstrated that the toe berm (6t rocks, 3:1 slope) was not stable at key singular locations, namely roundheads and roots, where direct impacts of breaking waves caused severe damage. Given the site conditions and the construction methods, the usual solutions consisting in increasing the rock size and/or placing the toe berm in a trench had to be ruled out. It was hence decided to reinforce the toe with artificial blocks and to use rectangular concrete blocks with holes. These blocks reduced the anti-stabilizing pressure difference between the top and bottom of the blocks (Tanimoto et al., 1996) and drag force due to the considerable current. They are more usually used at the toe of vertical caissons.

scholarly journals STABILITY OF RUBBLE MOUND BREAKWATERS WITH A BERM

2012 ◽  
Vol 1 (33) ◽  
pp. 10
Author(s):  
Marcel Van Gent ◽  
Gregory M. Smith ◽  
Ivo Van der Werf
Keyword(s):  
Rock Slope ◽  
Slope Angle ◽  
Rock Slope Stability ◽  
Rock Slopes ◽  
Test Results ◽  
Physical Model Tests ◽  
Rubble Mound ◽  
The Stability ◽  
Rubble Mound Breakwaters ◽  
Rock Size

The stability of rock slopes with a horizontal berm has been studied by means of physical model tests. This paper is focussed on the rock slope stability of the slopes above and below the berm. By applying a berm the rock size can be reduced compared to the required rock size for a straight slope without a berm. This reduction can be significant for the slope above the berm. The influence of the slope angle (1:2 and 1:4), the width of the berm, the level of the berm, and the wave steepness have been investigated. Based on the test results prediction formulae have been derived to quantify the required rock size for rubble mound breakwaters with a berm.

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.

scholarly journals CEOHYDRAULIC INVESTIGATIONS OF RUBBLE MOUND BREAKWATERS

1988 ◽  
Vol 1 (21) ◽  
pp. 166 ◽  
Author(s):  
W. Burger ◽  
H. Oumeraci ◽  
H.W. Partenscky
Keyword(s):  
Pore Pressure ◽  
Scale Effects ◽  
Numerical Models ◽  
Model Tests ◽  
Physical Models ◽  
Core Material ◽  
Scale Model ◽  
Small Scale ◽  
Rubble Mound ◽  
Rubble Mound Breakwaters

Due to the increase of ship sizes in recent decades a number of harbours and terminals have been built in deeper waters. Accordingly, the structures which have to provide protection against wave action become higher, too. In most cases, these protective structures are of the rubble mound type. Under such conditions the flow induced by waves within the breakwater and the related geotechnical behaviour of the rubble mound fill become more significant fcr the overall stability and should be considered in the design. In addition, it is known that the scales usually adopted in hydraulic models (1:30 to 1:60) for investigating the stability of large rubble mound breakwaters generally lead to scale effects with respect to the flow field inside the breakwater. This means that small-scale model tests are not appropriate for investigating the internal flow patterns or for evaluating the pore pressure field induced by the incident waves in,the core material. because of the uncontrolled conditions in the prototype, and since the actual permeability of the prototype rubble mound fill cannot be predicted (segregation, settlement, variation in grading, etc.), the use of large-scale physical models seems to be the most promising method for basic investigations of this kind. Moreover, the results of such largescale model tests may be used to validate the usual smaller scale models and to calibrate numerical models. Therefore, it is one of the objectives of our research programme on rubble mound breakwaters, which started in 1987, to concentrate on the evaluation of the wave-induced flow and pore pressure distribution within the breakwater.

Prototype measurements and small-scale model tests of wave overtopping at shallow rubble-mound breakwaters: the Ostia-Rome yacht harbour case

2009 ◽  
Vol 56 (2) ◽  
pp. 154-165 ◽  
Author(s):  
Leopoldo Franco ◽  
Jimmy Geeraerts ◽  
Riccardo Briganti ◽  
Marc Willems ◽  
Giorgio Bellotti ◽  
...  
Keyword(s):  
Model Tests ◽  
Scale Model ◽  
Small Scale ◽  
Wave Overtopping ◽  
Rubble Mound ◽  
Rubble Mound Breakwaters ◽  
Small Scale Model

scholarly journals POLOS PACKING DENSITY AND EFFECT OF RELATIVE BLOCK DENSITY

1978 ◽  
Vol 1 (16) ◽  
pp. 137
Author(s):  
J.A. Zwamborn
Keyword(s):  
Physical Properties ◽  
Packing Density ◽  
Model Tests ◽  
Test Results ◽  
Regular Waves ◽  
Shape Factors ◽  
Flume Tests ◽  
Testing Techniques ◽  
The Mean ◽  
Packing Densities

Accuracy and compatibility of measuring and testing techniques are discussed briefly and a plea is made for standardization to avoid, as far as possible, deviations in test results of different laboratories. One of the main causes of these differences is inconsistency in Dolos packing densities and corresponding layer thicknesses or shape factors. In an attempt to alleviate this problem three placing densities, namely 'light', 'mean' and 'dense' have been defined and their physical properties determined. Flume tests with regular waves, and Dolos armour units at these packing densities, showed very little difference in stability and, considering practical limitations during construction, it is suggested that the 'mean' packing density be used for a 'first design', followed by proper model tests. The results of tests with model Dolosse using three different unit densities were inconclusive and further tests using a wider range of densities are underway.

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