New project: Optimisation of Pile Installation through Scour protection (OPIS)
Reducing the cost of foundation construction for offshore wind turbines
We are pleased to announce that the GROW project OPIS has received a subsidy from RVO and that the project started in January 2023. In the research project, we aim to shorten the construction time of foundations for offshore wind turbines. This will lead to significant cost savings. The emission of greenhouse gasses from the vessels’ engines is also reduced because fewer transport movements are needed.
In this project, we aim to better understand pile penetration through scour protection to enable an optimised and less risky installation of monopiles. Therefore, we need to improve our understanding of the driving mechanism and the response of the scour protection layer under a range of different conditions, such as subsurface conditions, rock size and shape, dimensions of the monopile, and scour protection properties.
In the project, we will perform a series of small-scale laboratory tests with an object penetrating a granular medium under different conditions. In the second step, we will execute medium-scale laboratory tests to calibrate and verify numerical models based on the discrete element method (DEM) and finite element method (FEM).
Based on the data we gathered in the laboratory-test, we will develop a computational model that predicts the maximum force required to penetrate the scour protection layer and, thus, whether a successful pile penetration can be obtained for a given scour protection design, such as grading and thickness.
If self-weight penetration fails, impact or vibrating pile driving may be required to install the monopile finally. In OPIS, we perform activities to understand better the impact of such technologies on scour protection and pile integrity.
With the knowledge gained, we will investigate innovative solutions to facilitate the penetration of piles during installation. This could be, for example, by adjusting the design of the pile tip or applying a so-called doughnut design, where less scour material is placed on the monopile location. Finally, we will explore innovative solutions that enable effective remedial actions when penetration fails, for instance, pile driving with limited applied energy when a pile gets stuck in the scour layer.
The partners of this project consortium are CAPE Holland, Deltares, DEME Offshore, Heerema Engineering Solutions, Heerema Marine Contractors, Jan de Nul, TU Delft, Seaway7 and Vattenfall.