Publikasjoner
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Su, Pin-Tzu; Didenkulova, Irina & Jensen, Atle
(2025).
Transport of tsunami-driven debris over a slope.
Ocean Engineering.
ISSN 0029-8018.
348.
doi:
10.1016/j.oceaneng.2025.124028.
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We study tsunami-induced transport of heavy and floating debris over a slope. The work is performed experimentally in a small wave flume, which is 3 m long and 0.1 m wide with the water depth of 0.05 m. Tsunami is modeled by breaking solitary waves with amplitude (a), normalized by the water depth (hw) equal to a/hw = 0.5. Three succeeding waves propagate towards a sedimentary beach breaking on the slope, and impact debris which are initially placed at different locations along the slope with respect to the wave breaking point. We use spherical debris with two different densities. The heavy ones are lying on the slope, while the light ones are floating at the surface. The sea bed slope is covered with 0.02 m layer of sand. We use sediments of two different sizes to study the interaction of debris with sedimentary environment. The main measured parameter is displacement of the debris along the slope, which is analyzed with respect to the characteristics (densities) of the debris, their initial positions, number of consecutive waves and the size of the sediments
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Su, Pin-Tzu; Didenkulova, Ira & Jensen, Atle
(2024).
Solitary wave-induced boulder transport on a beach.
Ocean Engineering.
ISSN 0029-8018.
313.
doi:
10.1016/j.oceaneng.2024.119318.
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The influence of sediment on a slope on boulder transport is studied experimentally at the Hydrodynamics Laboratory of the University of Oslo. Experiments are conducted in a small 3 m long and 10 cm wide wave tank, filled with 5 cm of water. The transport of boulders is induced by breaking solitary waves with an amplitude normalized by water depth a/ℎ𝑤 = 0.5. Generated solitary waves propagate towards a 1:10 beach. The experiments are conducted in two set-ups: (i) empty Polymethyl methacrylate (PMMA) bottom of the flume, (ii) the slope covered by a thin layer of 65 μm sand. The boulders are represented by concrete blocks of different shape and size. They are placed alternately (one at a time) at different locations on the beach slope with respect to wave breaking point. Transport of boulders and their dynamics is studied with respect to boulder characteristics (size, orientation), their initial position and inclusion of sediment. It is shown that presence of sediment enhances boulder transport. In particular, in this set-up, the presence of sediment increased the boulder transport in 2–5 times. The maximum displacement increase was observed for boulders with the smallest length and height and the largest width initially located at the breaking position. Another interesting result regards the type of boulder motion. The boulders experienced either sliding or turning over. Boulders whose height was at least twice as large as their length exhibited turning-over. This held for boulders placed both on an empty PMMA slope and on a sedimentary slope. However, the largest boulder displacement on an empty PMMA slope occurred due to turning over, while on a sedimentary slope it occurred due to sliding.
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Publisert
15. feb. 2022 13:42
- Sist endret
25. nov. 2022 11:33