TY - JOUR

T1 - Spatio-temporal analysis of scour around complex offshore foundations under clear water and live bed conditions

AU - Welzel, Mario

AU - Schendel, Alexander

AU - Satari, Ramish

AU - Neuweiler, Insa

AU - Schlurmann, Torsten

N1 - Funding Information: This study has been carried out within the Collaborative Research Center (CRC) 1463 “Integrated design and operation methodology for offshore megastructures” and is funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – SFB 1463–434502799. As well as within the project TEXBASE (KF 3316902Kl4) which was funded by the ZIM program “Zentrales Innovationsprogramm Mittelstand” which is a funding programme of the BMWK (Federal Ministry for Economic Affairs and Climate Action).

PY - 2024/4/15

Y1 - 2024/4/15

N2 - This study investigates scour around offshore wind foundations, focusing on two complex structures with varying degrees of flow blockage: a novel hybrid gravity-based jacket (structure “A") and a conventional four-legged jacket (structure “B"). As offshore structures like jackets become more prevalent, mainly due to their structural stability and growth of offshore wind energy in general, understanding scouring phenomena around complex structures is crucial. Laboratory tests under steady flow clear-water and live-bed conditions, with measurements of 3D laser scans for test durations of 15, 90, and 420 min were conducted. In addition the scour development over time was measured and analyzed with eight echo sounders. The findings confirm that scouring around complex structures displays significant variability in dependency of the structure type, making standardization a challenging task. However, some common trends can be derived. Under live-bed conditions, both types of structures exhibit global erosion, regardless of the complexity or flow obstruction of the structure. The spatial erosion depth, relative to the footprint, is markedly higher (2.5 times) for the gravity-based structure as opposed to the jacket structure. In clear-water conditions, no global scour was observed for both structures and a very similar spatial erosion depth was reached after 420 min.

AB - This study investigates scour around offshore wind foundations, focusing on two complex structures with varying degrees of flow blockage: a novel hybrid gravity-based jacket (structure “A") and a conventional four-legged jacket (structure “B"). As offshore structures like jackets become more prevalent, mainly due to their structural stability and growth of offshore wind energy in general, understanding scouring phenomena around complex structures is crucial. Laboratory tests under steady flow clear-water and live-bed conditions, with measurements of 3D laser scans for test durations of 15, 90, and 420 min were conducted. In addition the scour development over time was measured and analyzed with eight echo sounders. The findings confirm that scouring around complex structures displays significant variability in dependency of the structure type, making standardization a challenging task. However, some common trends can be derived. Under live-bed conditions, both types of structures exhibit global erosion, regardless of the complexity or flow obstruction of the structure. The spatial erosion depth, relative to the footprint, is markedly higher (2.5 times) for the gravity-based structure as opposed to the jacket structure. In clear-water conditions, no global scour was observed for both structures and a very similar spatial erosion depth was reached after 420 min.

KW - Erosion patterns

KW - Jacket

KW - Laboratory tests

KW - Scour

KW - Sediment transport

UR - http://www.scopus.com/inward/record.url?scp=85185536258&partnerID=8YFLogxK

U2 - 10.1016/j.oceaneng.2024.117042

DO - 10.1016/j.oceaneng.2024.117042

M3 - Article

AN - SCOPUS:85185536258

VL - 298

JO - Ocean engineering

JF - Ocean engineering

SN - 0029-8018

M1 - 117042

ER -