Revisiting statistical properties of surf parameter with characteristic wave parameters for single random waves including spectral bandwidth effects

2021 ◽  
pp. 147509022110353
Author(s):  
Dag Myrhaug ◽  
Hong Wang ◽  
Lars Erik Holmedal ◽  
Hongtao Li
Keyword(s):  
Wave Height ◽  
Joint Distribution ◽  
Parametric Model ◽  
Wave Period ◽  
Small Scale ◽  
Spectral Bandwidth ◽  
Joint Distributions ◽  
Wide Range ◽  
Rubble Mound ◽  
Rubble Mound Breakwaters

Results from a comparative study of the joint distribution of surf parameter and wave period are provided. First, two transformed joint distributions of wave height and wave period are compared. One of the distributions is a parametric model originating from a best fit to relatively broad-band field data covering a wide range of wave conditions, whilst the other distribution is theoretically based. It appears that the theoretically based distribution does not represent the features of the parametric model especially well, suggesting that parametric models should be used to describe relatively broad-banded data. Then, the theoretically based joint distribution of wave height and wave period is transformed to the joint distributions of surf parameter with wave height and wave period and it is demonstrated how these distributions are affected by the spectral bandwidth. Finally, the theoretically based distribution of wave height and wave period is also transformed to the joint distribution of wave runup time and wave period due to its relation to the stability of rubble-mound breakwaters. Comparisons are made with a limited set of data representing results from small-scale laboratory experiments related to stability of rubble-mound breakwaters. The agreement between measurements and predictions of the distribution of the surf parameter is fair, whilst the agreement is poorer for the probability of resonance.

scholarly journals Double Entropy Joint Distribution Function and Its Application in Calculation of Design Wave Height

Entropy ◽  
2019 ◽  
Vol 21 (1) ◽  
pp. 64 ◽  
Author(s):  
Guilin Liu ◽  
Baiyu Chen ◽  
Song Jiang ◽  
Hanliang Fu ◽  
Liping Wang ◽  
...  
Keyword(s):  
Distribution Function ◽  
Maximum Entropy ◽  
Wave Height ◽  
Joint Distribution ◽  
Height Function ◽  
Copula Function ◽  
Wave Period ◽  
Ocean Engineering ◽  
Joint Distribution Function ◽  
Design Wave Height

Wave height and wave period are important oceanic environmental factors that are used to describe the randomness of a wave. Within the field of ocean engineering, the calculation of design wave height is of great significance. In this paper, a periodic maximum entropy distribution function with four undetermined parameters is derived by means of coordinate transformation and solving conditional variational problems. A double entropy joint distribution function of wave height and wave period is also derived. The function is derived from the maximum entropy wave height function and the maximum entropy periodic function, with the help of structures of the Copula function. The double entropy joint distribution function of wave height and wave period is not limited by weak nonlinearity, nor by normal stochastic process and narrow spectrum. Besides, it can fit the observed data more carefully and be more widely applicable to nonlinear waves in various cases, owing to the many undetermined parameters it contains. The engineering cases show that the recurrence level derived from the double entropy joint distribution function is higher than that from the extreme value distribution using the single variables of wave height or wave period. It is also higher than that from the traditional joint distribution function of wave height and wave period.

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

Wave Induced Hydraulic Pressure by Wave Conditions of Pontoon Typed Floating Structures

2011 ◽  
Vol 250-253 ◽  
pp. 1444-1447
Author(s):  
Youn Ju Jeong ◽  
Young Jun You ◽  
Yoon Koog Hwang
Keyword(s):  
Wave Height ◽  
Experimental Studies ◽  
Type A ◽  
Wave Period ◽  
Small Scale ◽  
Hydraulic Pressure ◽  
Floating Structures ◽  
Wave Conditions ◽  
Wave Induced

In this study, in order to verify wave induced buoyancy effects by wave conditions of wave height and period, experimental studies were conducted to the floating structures of pontoon type. A series of small-scale tests with various wave cases were performed to the pontoon models. Two small-scale pontoon models having different bottom details were fabricated and tested under the five different wave cases. Six hydraulic pressure gauges were attached on the bottom of pontoon models and wave induced hydraulic pressure was measured during the tests. Finally, hydraulic pressure subjected to the bottom of pontoon models were compared with each other. As the results of this study, it was found that wave induced hydraulic pressures at bottom were dependent on the wave period as well as wave height, and waffled bottom shape hardly influenced on wave induced hydraulic pressure.

scholarly journals Damage in Rubble Mound Breakwaters. Part II: Review of the Definition, Parameterization, and Measurement of Damage

2020 ◽  
Vol 8 (5) ◽  
pp. 306 ◽  
Author(s):  
Álvaro Campos ◽  
Rafael Molina-Sanchez ◽  
Carmen Castillo
Keyword(s):  
Methodological Approach ◽  
Historical Review ◽  
Small Scale ◽  
Damage Models ◽  
Measuring Techniques ◽  
Physical Tests ◽  
Rubble Mound ◽  
Many Sources ◽  
Rubble Mound Breakwaters ◽  
Near Future

Damage in rubble mound breakwaters has been addressed for more than 80 years and, as reported in “Part I: Historical review of damage models”, a considerable number of hydraulic instability models have been proposed up to date. Most of them were developed from small-scale physical tests, based on damage descriptors not always parameterized nor measured in the same way, which indeed complicates the comparison and reproducibility from different experimental data sources. The latter is increased by the lack of a standardized methodological approach inside an experimental and measuring process that involves many sources of uncertainty. Currently, the latest innovations applicable to damage measurement, together with the growing demand of reliable decision-making tools for conservation/maintenance strategies and structural/operational risk management, venture an upcoming proliferation of prototype monitoring, as well as new approaches aimed to characterize the stochastic nature of damage evolution. In this context, this paper is meant to review the concept of damage in rubble mound breakwaters, the different proposals for its parameterization, the past and present measuring techniques, and main challenges in the near future.

Copula-Based Bivariate Modelling of Significant Wave Height and Wave Period and the Effects of Climate Change on the Joint Distribution

2016 ◽  
Author(s):  
Erik Vanem
Keyword(s):  
Climate Change ◽  
Wave Height ◽  
Significant Wave Height ◽  
Joint Distribution ◽  
Wave Period ◽  
Dependence Structure ◽  
Zero Crossing ◽  
Conditional Model ◽  
Significant Wave ◽  
Modelling Techniques

The joint distribution of several met-ocean variables is required for risk assessment and load and response calculations in marine engineering. For example, a joint description is needed to construct environmental contours for probabilistic structural reliability analyses. Typically, the joint distribution of significant wave height and wave period is required as a minimum. This paper presents a study on various bivariate modelling techniques for the joint distribution of significant wave height and zero-crossing wave period, i.e. a conditional model, a bi-variate log-normal model and several meta-models based on parametric copulas. Each of the models is fitted to data generated from a numerical wave model for the current climate and for two future climates consistent with the RCP 4.5 and RCP 8.5 scenarios. Thus, the objective of this study is twofold. First, the joint models obtained by the various modelling techniques will be compared. Secondly, the potential effect of climate change on the simultaneous distribution of significant wave height and wave period will be explored. The results indicate that straightforward application of many of the most common families of copulas fails to capture the dependence structure in the data, and that the conditional model performs better than these naive approaches. However, if more advanced copula construction techniques are applied, significant improvements can be achieved. The results also suggest that significant wave height and zero-crossing wave period tend to be more correlated in a future climate, at least in the extremes.

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.

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