Extended characterization of damage in rubble mound scour protections
In: Coastal Engineering: An International Journal for Coastal, Harbour and Offshore Engineers. Elsevier: Amsterdam; Lausanne; New York; Oxford; Shannon; Tokyo. ISSN 0378-3839; e-ISSN 1872-7379
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| Auteurs | | Top |
- Fazeres-Ferradosa, T.
- Welzel, M.
- Schendel, A.
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- Baelus, L.
- Santos, P.R.
- Pinto, F.T.
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| Abstract |
The analysis of damage in rubble mound scour protections is crucial for the armour stability assessment. Former methodologies focused on the analysis of the maximum damage number. This work introduces a complementary methodology to determine and characterize damage statistical distribution based on a flexible arrangement of sub-areas. The sub-areas are overlapping and can be varied in size, allowing a refined damage analysis. To capture the variation of damage with changing sub-area layout, the methodology is coupled with a statistical evaluation of damage numbers, which is enabled by the definition of a grid ratio between armour stone size and sub-area size, (Dn50)2/Asub. The methodology is applied to high resolution bathymetric surveys from two stability tests of large-scale rip-rap scour protection around a monopile foundation and combined wave and current loading. Results show that the methodology provides a complementary understanding of damage distribution to the maximum damage acquired from previous methodologies. In addition, it allows a comparison of damage characteristics between tests despite different shapes of the foundation. Research concludes that the size of the sub-areas influences significantly the damage description. Characteristic measures as the maximum damage number and standard deviation become stable at a grid ratio (Dn50)2/Asub equal to 1/4. |
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