Physical modelling of monopile penetration through scour protection of different grain sizes
Physical modelling of monopile penetration through scour protection of different grain sizes
The offshore wind industry has expanded rapidly, with more than 80% of offshore wind turbines using monopile foundations. In many cases, scour protection is installed around the foundations of offshore structures to safeguard against seabed loss caused by erosion. In some cases, where scour protection has been pre-placed as a cost-saving measure, the piles need to penetrate through it to reach the target depth. However, the ability of a pile to effectively penetrate an existing scour protection layer remains uncertain, and the impact of rock materials on pile penetration resistance is still not well understood. Single-layer scour protection is composed of a broadly graded layer of rock material, which can affect the penetration resistance of piles through the pre-installed scour layer due to grain size effects (relative to the pile cross-section and underlying soil type). To replicate full-scale stress conditions in small-scale models, centrifuge tests were conducted to study the effect of grain size on the penetration resistance of piles through a scour protection layer overlaying sand. Small-scale open-ended piles of different diameters were utilised in this study. The results reveal that while increasing the diameter of the piles leads to higher penetration resistance as expected, the penetration resistance is also highly dependent on grain size, when this is comparable to the pile annular wall thickness.
R. Jahanshahi; Tayyib Jawid; Mike Brown; Jorge Castro; Craig Davidson; Marina Miranda; Wei Wang
11th International Conference on Physical Modelling in Geotechnics (ICPMG2026)
Special Session 3: Physical Modelling of Installation of Fixed OWT Foundations
https://doi.org/10.53243/ICPMG2026-272