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@ D McParland: In the section on continuing development, there's a table showing values of a, b, c, d for some probabilities. The table has no source. Maybe it reflects the formulas above? I don't see where the values of a, b, c, d come from.
The lowest probability in the table is 1 in 1,000. For waves with 10-second periods, there are 3 million per year, so I'd like to extend the table to a much smaller probability, to identify the highest runups over the long course of of a building's life, to know the freeboard needed. Of course this would also need a distribution of wave heights. Numbersinstitute ( talk) 22:52, 1 July 2024 (UTC)
- Hi, thanks for your comments. I had been meaning some time ago to go back and update the article somewhat with more detail and citations, but haven't got round to it yet. The coefficients originate from empirical studies and formulae developed by van der Meer (1988). These coefficients are specifically used in the run-up formula for rubble mound breakwaters, which takes into account factors such as permeability and wave characteristics. They apply only to rock armoured slopes, so would not be relevant in e.g. concrete armour units or a smoother, asphalt type revetment or breakwater. They reflect the fact that, in irregular random seas, the run-up value changes considerably from wave to wave. Just now I added in another reference which gives a more detailed explanation (Burcharth). To extend the table to a smaller probability, a statistical model is required as you say, combined with the run-up formula. In the next few days I'll try and revisit the article to make this clearer.
D McParland (
talk)
21:52, 2 July 2024 (UTC)
- Related, but not the same, is
Figure 18, showing probabilities of extreme crest heights at a shallow and a deep ocean buoy, including the estimated highest individual crest in periods of time ranging freom 10 to 1,000 years. Structures on or near oceans need to consider the rare crests, since cumulative risk of them happening at least once in the 50 or 200-year lifetime of a structure is significant.
Numbersinstitute (
talk)
19:53, 3 July 2024 (UTC)
- Yes that's true, but this article is about wave run-up at coastal structures (revetments, dikes/levees), so the behaviour of offshore waves is not so relevant. The primary focus of Mackay's paper is on offshore environments, including deep water and nearshore (but still offshore) locations. The methodologies and data sets used are oriented towards understanding wave conditions that affect floating offshore structures, such as platforms and offshore wind turbines, etc. Wave run-up involves additional factors such as interaction with the shoreline, which is not the primary concern of the statistical models and analyses presented in the paper. D McParland ( talk) 12:51, 5 July 2024 (UTC)
- Related, but not the same, is
Figure 18, showing probabilities of extreme crest heights at a shallow and a deep ocean buoy, including the estimated highest individual crest in periods of time ranging freom 10 to 1,000 years. Structures on or near oceans need to consider the rare crests, since cumulative risk of them happening at least once in the 50 or 200-year lifetime of a structure is significant.
Numbersinstitute (
talk)
19:53, 3 July 2024 (UTC)
|
| This article contains a translation of Golfoploop from nl.wikipedia. |
| This article has not yet been rated on Wikipedia's
content assessment scale. It is of interest to the following WikiProjects: | ||||||||||
| |||||||||||
@ D McParland: In the section on continuing development, there's a table showing values of a, b, c, d for some probabilities. The table has no source. Maybe it reflects the formulas above? I don't see where the values of a, b, c, d come from.
The lowest probability in the table is 1 in 1,000. For waves with 10-second periods, there are 3 million per year, so I'd like to extend the table to a much smaller probability, to identify the highest runups over the long course of of a building's life, to know the freeboard needed. Of course this would also need a distribution of wave heights. Numbersinstitute ( talk) 22:52, 1 July 2024 (UTC)
- Hi, thanks for your comments. I had been meaning some time ago to go back and update the article somewhat with more detail and citations, but haven't got round to it yet. The coefficients originate from empirical studies and formulae developed by van der Meer (1988). These coefficients are specifically used in the run-up formula for rubble mound breakwaters, which takes into account factors such as permeability and wave characteristics. They apply only to rock armoured slopes, so would not be relevant in e.g. concrete armour units or a smoother, asphalt type revetment or breakwater. They reflect the fact that, in irregular random seas, the run-up value changes considerably from wave to wave. Just now I added in another reference which gives a more detailed explanation (Burcharth). To extend the table to a smaller probability, a statistical model is required as you say, combined with the run-up formula. In the next few days I'll try and revisit the article to make this clearer.
D McParland (
talk)
21:52, 2 July 2024 (UTC)
- Related, but not the same, is
Figure 18, showing probabilities of extreme crest heights at a shallow and a deep ocean buoy, including the estimated highest individual crest in periods of time ranging freom 10 to 1,000 years. Structures on or near oceans need to consider the rare crests, since cumulative risk of them happening at least once in the 50 or 200-year lifetime of a structure is significant.
Numbersinstitute (
talk)
19:53, 3 July 2024 (UTC)
- Yes that's true, but this article is about wave run-up at coastal structures (revetments, dikes/levees), so the behaviour of offshore waves is not so relevant. The primary focus of Mackay's paper is on offshore environments, including deep water and nearshore (but still offshore) locations. The methodologies and data sets used are oriented towards understanding wave conditions that affect floating offshore structures, such as platforms and offshore wind turbines, etc. Wave run-up involves additional factors such as interaction with the shoreline, which is not the primary concern of the statistical models and analyses presented in the paper. D McParland ( talk) 12:51, 5 July 2024 (UTC)
- Related, but not the same, is
Figure 18, showing probabilities of extreme crest heights at a shallow and a deep ocean buoy, including the estimated highest individual crest in periods of time ranging freom 10 to 1,000 years. Structures on or near oceans need to consider the rare crests, since cumulative risk of them happening at least once in the 50 or 200-year lifetime of a structure is significant.
Numbersinstitute (
talk)
19:53, 3 July 2024 (UTC)