Numerical And Physical Modelling Of The Pore Pressure Development Around A Monopile Foundation

Abstract

Offshore wind has favoured the use of monopile foundation due to its simplicity in design, construction and industrial scalability. The stability of the monopile foundations can be affected not only by the direct action of wave loads but also by the response of the surrounding seabed. Numerical and physical modelling can be used to simulate the wave-structure-seabed interaction and accurately predict the wave-induced seabed response around the monopile foundation.

Within this context, a 3D coupled numerical model is developed to investigate the excess pore pressure development around a monopile foundation and the accompanying changes in the effective stress of the seabed soil. In addition to the coupled hydrodynamic-geotechnical analyses, physical model tests have been performed at the Coastal & Ocean Basin (COB) in Ostend (BE) within the SOILTWIN project in December 2023. These tests provide insight into the soil behaviour around the monopile foundation based on pore pressure measurements. The comparison of the numerical results with experimental data is essential for an improved calibration of the numerical model as well as for a better understanding of the soil response under various wave loading conditions. The experimental setup and the initial findings will be discussed during the conference.