Deployment of renewable energy is essential to reach a carbon neutral economy. Offshore wind farms have caught the interest of many developed countries since they are an essential source of green energy. The interest of this thesis lays in the design of the foundation used for offshore wind farms, in particular the interaction between the monopiles and the scour protection layer. An optimised one-stage installation process for the scour protection is investigated, which consists of first placing the rock armour and then driving the monopile through the entire scour protection layer. This is an efficient method to reduce the installation time and the operational cost.
The purpose of this research is to identify the limitations which are related to the penetration of the monopile through the stone armour. The scour protection material is composed of large diameter rocks, which can hinder the penetration of the pile, or even damage the tip of the pile. A restricting ratio of the mean size of the rock (d50) to the thickness of the monopile wall (w) is explored, as well as an investigation of the effect of penetration resistance on different material and geometry characteristics. The first research method employed is a literature study, which proves that the analytical formulation of the axial capacity provided by the available standards is inappropriate for the application of this thesis. Thus, two other research methods are identified, which include designing an experimental small-scale test and a Discrete Element Model (DEM) of a penetration test.

Bulk handling grabs wear due to interaction with bulk material. In this research the geometrical shape of the grab is adjusted to reduce this wear. A DEM simulation using an iron ore pellet material model, created by S. Lommen, is used to assess different concepts. The material model is validated for forces, but not for wear. Wear measurements are performed on an existing grab. The results are compared to the simulation results to validate the material model. This comparison shows that adjustments are required to make the model more accurate for wear. The model is adjusted by changing the static friction coefficient. This adjusted model is used to assess the concept solutions. The concept solutions aim to reduce wear during unloading of the grab. The results show that reducing wear by changing the geometrical shape of the grab is possible. However, there is a trade off with the performance of the grab.