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Ocean Systems Engineering Volume 6, Number 2, June 2016 , pages 161-189 DOI: https://doi.org/10.12989/ose.2016.6.2.161 |
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Scour around vertical piles due to random waves alone and random waves plus currents on mild slopes |
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Muk Chen Ong, Dag Myrhaug and Ping Fu
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| Abstract | ||
| This paper provides a practical stochastic method by which the maximum equilibrium scour depth around a vertical pile exposed to random waves plus a current on mild slopes can be derived. The approach is based on assuming the waves to be a stationary narrow-band random process, adopting the Battjes and Groenendijk (2000) wave height distribution for mild slopes including the effect of breaking waves, and using the empirical formulas for the scour depth on the horizontal seabed by Sumer and Freds e (2002). The present approach is valid for wave-dominant flow conditions. Results for random waves alone and random wave plus currents have been presented and discussed by varying the seabed slope and water depth. An approximate method is also proposed, and comparisons are made with the present stochastic method. For random waves alone it appears that the approximate method can replace the stochastic method, whereas the stochastic method is required for random waves plus currents. Tentative approaches to related random wave-induced scour cases on mild slopes are also suggested. | ||
| Key Words | ||
| scour depth; vertical pile; mild slope; random waves; current; stochastic method | ||
| Address | ||
| Muk Chen Ong: Department of Mechanical and Structural Engineering and Materials Science, University of Stavanger Stavanger, Norway Dag Myrhaug and Ping Fu: Department of Marine Technology, Norwegian University of Science and Technology Trondheim, Norway | ||
