WP4 – Numerical modelling of offshore foundations in weak rock

Work Package 4 develops and evaluates numerical modelling approaches for offshore foundations installed in weak rock formations, with an initial focus on chalk. Its purpose is to identify suitable analysis methods, constitutive models and material parameters for representing weak rock behaviour in offshore foundation design applications. The work package focuses primarily on pile-type foundations, including monopiles, jacket piles and pile anchors. Numerical modelling will be used to investigate pile - rock interaction during installation and subsequent operational loading. Particular attention will be given to the effects of rock fracturing, drainage conditions, interface behaviour, stiffness degradation and cyclic loading on foundation performance. The work package will also examine how constitutive models and modelling approaches can be adjusted or calibrated to better capture the behaviour of weak rock under offshore loading conditions.

The modelling will be benchmarked against laboratory element tests, penetrometer tests, available field data and internal project data. This provides a basis for understanding the links between rock behaviour, site investigation data and foundation response. Parametric studies will then be carried out to quantify how key rock properties and modelling assumptions influence installation behaviour, capacity, stiffness and serviceability performance.

The outcomes of WP4 will provide direct input to WP5 by translating detailed numerical analyses into simplified design guidance, spring formulations and parameter recommendations. In this way, WP4 forms the link between weak-rock characterisation, advanced numerical analysis and practical engineering design. The final deliverables will include guidance on the choice of modelling method, constitutive model, material parameter selection, model calibration and boundary-value problem set-up for offshore foundations in weak rock. The work package will support the development of a robust and practical design framework for offshore wind piles in weak rock.