scholarly journals STABILITY OF RUBBLE MOUND BREAKWATER

1980 ◽  
Vol 1 (17) ◽  
pp. 120 ◽  
Author(s):  
J. Feuillet ◽  
M. Sabaton
Keyword(s):  
Wave Height ◽  
Breaking Waves ◽  
Random Waves ◽  
Regular Waves ◽  
T Wave ◽  
Design Wave Height ◽  
Storm Duration ◽  
Equivalent Wave ◽  
Rubble Mound ◽  
The Stability

The stability of a rubble mound breakwater section, with 3 in 2 armour slope, was tested under random waves attack. Tests analysis shows that the equivalent wave height characterizing the spectrum to be used in a stability formula elaborated with regular waves (for instance the Hudson's formula) is the upper twentieth height of the distribution for a storm duration of 6 hours. An analytical expression of the damage evolution as function of time modulates this choice according to the storm duration. The same rubble mound breakwater was also tested under the action of regular breaking waves. The damage was expressed in terms of the four following parameters : H0 : wave height T : wave period Dp : water depth at the toe of the structure Djj : breaker depth without the breakwater For a given wave height, the most important damage occur when : °b In this case the design wave height must be increased by about 30 % when using a stability formula elaborated for non breaking waves.

scholarly journals IRREGULAR WAVE TESTS FOR COMPOSITE BREAKWATER FOUNDATIONS

1982 ◽  
Vol 1 (18) ◽  
pp. 128 ◽  
Author(s):  
Katsutoshi Tanimoto ◽  
Tadahiko Yagyu ◽  
Yoshimi Goda
Keyword(s):  
Wave Height ◽  
Significant Wave Height ◽  
Irregular Waves ◽  
Stability Number ◽  
Regular Waves ◽  
Significant Wave ◽  
Irregular Wave ◽  
Concrete Blocks ◽  
Rubble Mound ◽  
The Stability

The stability of armor units for the rubble mound foundations of composite breakwaters has been investigated under the action of irregular waves. The tests establish that irregular waves are more destructive than regular waves, when the height of regular waves is set equal to the significant wave height. The stability number, defined by Hudson, for quarry stones and concrete blocks with simple shapes is formulated on the basis of irregular wave tests. The stability number is expressed by two parameters of h'7/7]/3 and K, where h' is the crest depth of the rubble mound foundation, #1/3 is the design significant wave height, and K is a parameter for the combined effects of the relative water depth and the relative berm width of the rubble mound foundation to the wavelength. The design mass of armor units can be calculated by the stability equation with the stability number. The application of the proposed method to the results of the irregular wave tests demonstrates that the damage percent for the quarry stones is at most 3.5% at the design condition and the damage progresses rather gradually for the action of higher waves. On the other hand, the damage of the concrete blocks almost jumps beyond the design wave height. In particular, the drastic damage is often caused in the case of high rubble mound foundations. The proposed method is confirmed, however, to be applicable for the ordinary low mound foundations with a sufficient safety.

scholarly journals ENERGY LOSS AND SET-UP DUE TO BREAKING OF RANDOM WAVES

1978 ◽  
Vol 1 (16) ◽  
pp. 32 ◽  
Author(s):  
J.A. Battjes ◽  
J.P.F.M. Janssen
Keyword(s):  
Wave Height ◽  
Dissipation Rate ◽  
Breaking Waves ◽  
Breaking Wave ◽  
Height Distribution ◽  
Random Waves ◽  
Dissipation Of Energy ◽  
Wave Height Distribution ◽  
Set Up ◽  
Local Depth

A description is given of a model developed for the prediction of the dissipation of energy in random waves breaking on a beach. The dissipation rate per breaking wave is estimated from that in a bore of corresponding height, while the probability of occurrence of breaking waves is estimated on the basis of a wave height distribution with an upper cut-off which in shallow water is determined mainly by the local depth. A comparison with measurements of wave height decay and set-up, on a plane beach and on a beach with a bar-trough profile, indicates that the model is capable of predicting qualitatively and quantitatively all the main features of the data.

scholarly journals RANDOM BREAKING WAVES HORIZONTAL SEABED

1986 ◽  
Vol 1 (20) ◽  
pp. 68 ◽  
Author(s):  
Hans Peter Riedel ◽  
Anthony Paul Byrne
Keyword(s):  
Wave Height ◽  
Water Depth ◽  
Breaking Waves ◽  
Random Wave ◽  
Random Waves ◽  
Flume Experiments ◽  
Depth Ratio ◽  
Wave Trains ◽  
Monochromatic Waves

According to wave theories the depth limited wave height over a horizontal seabed has a wave height to water depth ratio (H/d) of about 0.8. Flume experiments with monochromatic waves over a horizontal seabed have failed to produce H/d ratios greater than 0.55. However designers still tend to use H/d 0.8 for their design waves. Experiments have been carried out using random wave trains in the flume over a horizontal seabed. These experiments have shown that the limiting H/d ratio of 0.55 applies equally well to random waves.

scholarly journals DAMAGE FUNCTIONS FCR A RUBBLE-MOUND BREAKWATER UNDER THE EFFECT OF SWELLS

1970 ◽  
Vol 1 (12) ◽  
pp. 96 ◽  
Author(s):  
Juan B. Font
Keyword(s):  
Experimental Data ◽  
Wave Height ◽  
Damage Functions ◽  
Storm Duration ◽  
Rubble Mound ◽  
Damage Condition ◽  
Damage Criteria

In this paper experimental data are given to aid in the design of a rubble-mound breakwater The use of armor damage functions is supported rather than the use of the wave height for the no damage condition Damage curves defined experimentally are proposed, for both rocks and tetrapods, for different wave storm durations and for different placing tech niques A determinant influence of storm duration is found for advanced damage of the armor layers The experiments with different placing techniques showed that stability coefficients based upon the no damage criteria, do not give a reliable picture of the ultimace strength of a rubble-mound breakwater.

Experimental Research on the Influences of Wave Height on Towing of 4-Bucket Foundation Platform

2011 ◽  
Vol 243-249 ◽  
pp. 4723-4727
Author(s):  
Cong Huan Le ◽  
Hong Yan Ding ◽  
Guo Hai Dong ◽  
Pu Yang Zhang
Keyword(s):  
Wave Height ◽  
Experimental Research ◽  
Water Pressure ◽  
Roll Motion ◽  
Regular Waves ◽  
Bucket Foundation ◽  
Head Waves ◽  
The Stability ◽  
Heave Motion ◽  
Better Than

Internal air pressure and water pressure of the buckets foundation, acceleration and dragging force of the 4-bucket foundation platform were determined to analyze the influences of wave height on towing when 4-Bucket foundation platform is towing in conditions of a certain towing velocity, mooring point position and draught in different regular waves based on the model test. Comparing platform towing in following and head waves, the heave motion of the latter is more strenuous than that of the former; the stability and seakeeping of the former is better than those of the latter. Roll motion, pitch motion and heave motion appear aggravate phenomenon with the increase of wave height.

scholarly journals STABILITY OF INTERLOCKING ARMOUR UNITS ON A BREAKWATER CREST

2012 ◽  
Vol 1 (33) ◽  
pp. 11 ◽  
Author(s):  
Ilse Van den Bosch ◽  
Erik Ten Oever ◽  
Pieter Bakker ◽  
Markus Muttray
Keyword(s):  
Wave Height ◽  
Water Depth ◽  
Packing Density ◽  
Single Layer ◽  
Hydraulic Model ◽  
Model Tests ◽  
Wave Steepness ◽  
Design Wave Height ◽  
The Stability ◽  
Hydraulic Stability

The hydraulic stability of single layer, interlocking armour units on low crested and submerged breakwaters was investigated in 2D hydraulic model tests. Displacements of armour units and rocking were monitored and have been applied as indicators for the armour layer stability on the crest, front and rear slope. The effect of freeboard, packing density and wave steepness on the armour layer stability have been investigated. The stability of interlocking concrete armour units on low crested and submerged structures is qualitatively different from rock armour. About 40% to 50% larger armour units are required on the seaward slope and crest of low crested structures (as compared to conventional high crested breakwaters). About 35% larger armour units are required on the rear slope. Larger armour units are not required on submerged breakwaters if the water depth on the crest exceeds 50% of design wave height.

scholarly journals THE EFFECT OF STORM DURATION ON RUBBLE MOUND BREAKWATER STABILITY

1968 ◽  
Vol 1 (11) ◽  
pp. 50 ◽  
Author(s):  
Juan B. Font
Keyword(s):  
Experimental Data ◽  
Double Layer ◽  
Wave Height ◽  
Periodic Waves ◽  
Destruction Process ◽  
Recurrence Period ◽  
Storm Duration ◽  
Rubble Mound ◽  
Very High ◽  
Selection Of

Experimental data are given to aid in the selection of the wave height for the design of a rubble mound breakwater as a function of the type and duration of the wave storm, and the allowed percentage of damage in the armour layers. In these experiments the model breakwater was subjected to the attack of periodic waves of height and in number according with the known statistical distribution for actual swells. — Some noteworthy differences were found In the effects of different duration storms. Observation of the destruction process of the breakwater with double layer of armour rocks, showed that the filter layers uncovering occurred always for armour damage percentages above 5$ and thus this last value is suggested as the ma_ ximum permissible in case of a storm of very high recurrence period.

scholarly journals DESIGNING BERM BREAKWATERS FOR DIFFERENT WAVE HEIGHTS AND DIFFERENT QUARRY YIELD

2017 ◽  
pp. 33
Author(s):  
Sigurdur Sigurdarson ◽  
Jentsje Van der Meer
Keyword(s):  
Wave Height ◽  
Initial Phase ◽  
Full Range ◽  
Stability Parameter ◽  
Design Rules ◽  
Design Wave Height ◽  
Final Design ◽  
Wave Heights ◽  
The Stability ◽  
Design Options

The paper demonstrates the use of the geometrical design rules for berm breakwaters in a potential project in Greenland. With practically no information about the sizes of armourstone that could be used for the design, the initial phase of the study looked at the full range of the stability parameter Hs/ΔDn50 of 1.7 to 3.0 for the design wave height of Hs=4.4 m. This corresponds to armourstone classes ranging from 5-15 t down to 1-3 t. Six different design options based on six different options for the largest stone class are compared. The final design then relies on the actual quarry yield, the total volume of material needed for the project and the construction equipment that can be brought to the site.

scholarly journals STABILITY ANALYSIS FOR A RUBBLE-MOUND FOUNDATION THROUGH IRREGULAR WAVE TEST

1982 ◽  
Vol 1 (18) ◽  
pp. 127
Author(s):  
Masato Yamamoto ◽  
Tsutomu Asakawa
Keyword(s):  
Stability Analysis ◽  
Wave Height ◽  
Surf Zone ◽  
Average Height ◽  
Critical Stability ◽  
Cover Layer ◽  
Irregular Wave ◽  
Design Purpose ◽  
Rubble Mound ◽  
The Stability

Irregular wave tests have been conducted to research into the stability characteristics of armor units for a rubble foundation of a composite breakwater. A cover layer to protect the rubble foundation from erosion had two layers of tetrapods. Waves higher than H]_/]_Q (the average height of the highest 10% of all waves) caused damage to armor units at the point of critical stability. This suggested that wave height changes in the surf zone should be taken into consideration for design purpose.

scholarly journals Breaking-Wave Induced Transient Pore Pressure in a Sandy Seabed: Flume Modeling and Observations

2021 ◽  
Vol 9 (2) ◽  
pp. 160
Author(s):  
Changfei Li ◽  
Fuping Gao ◽  
Lijing Yang
Keyword(s):  
Pore Pressure ◽  
Wave Height ◽  
Wave Breaking ◽  
Breaking Waves ◽  
Breaking Wave ◽  
Regular Waves ◽  
Large Wave ◽  
Pore Pressures ◽  
Linear Waves ◽  
Wave Induced

Previous studies on wave-induced pore pressure in a porous seabed mainly focused on non-breaking regular waves, e.g., Airy linear waves or Stokes non-linear waves. In this study, breaking-wave induced pore pressure response in a sandy seabed was physically simulated with a large wave flume. The breaking-wave was generated by superimposing a series of longer waves onto the foregoing shorter waves at a specified location. Water surface elevations and the corresponding pore pressure in the process of wave breaking were measured simultaneously at three typical locations, i.e., at the rear, just at, and in front of the wave breaking location. Based on test results, characterization parameters are proposed for the wave surface elevations and the corresponding pore-pressures. Flume observations indicate that the wave height was greatly diminished during wave breaking, which further affected the pore-pressure responses. Moreover, the measured values of the characteristic time parameters for the breaking-wave induced pore-pressure are larger than those for the free surface elevation of breaking-waves. Under the action of incipient-breaking or broken waves, the measured values of the amplitude of transient pore-pressures are generally smaller than the predicted results with the analytical solution by Yamamoto et al. (1978) for non-breaking regular waves with equivalent values of characteristic wave height and wave period.

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