Simulating monopile installation through scour protection using the Discrete Element Method

Over 5000 offshore wind turbine generators have been installed in the past decades. 80% of these wind turbines have a monopile foundation. Monopiles are hollow steel tubular piles with a diameter of up to 10m. The first phase of the monopile installation consists of the self-weight penetration into the seabed due to the mass of the monopile....

Influence of scour protection layers on the lateral response of monopile in dense sand

The scour protection layers are usually installed around the monopiles to prevent the formation of scour hole. While extensive studies have been performed on the effectiveness of scour protection layer as mitigation measure, no study to date has been found to quantify the influence of scour protection layer on the lateral response of...

Assessing the drivability of a monopile through the rock armour layer: An analysis using Discrete Element Method and small-scale testing

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...

Experimental study on wave-induced scour in front of sloping coastal structures and the influence of bed protection

The erosion of the seabed in front of coastal structures induced by waves can lead to multiple types of failure instability or function of the structure. On this topic most research has been done into erosion in front of vertical structures. For sloping structures a knowledge gap exists in the understanding of the processes that lead to erosion...

On the toe stability of rubble mound structures

Toe design is an important task for coastal engineers as it ensures the stability of the main armor layer and prevents scour in front of the armor slope. Several laboratory experiments have been conducted to investigate the toe stability using different testing approaches, i.e. damage due to a single test condition and cumulative damage due...

Design of the scour protection as part of the DELTA 21 project

Nature-enhancing design of scour protection for monopiles in the North Sea

A combination of the growth of the offshore wind energy sector and the decline in both species richness and species abundance in the North Sea has inspired the goal to use the scour protection in wind farms as a means to enhance marine life. Present research has focused on general changes which are to be applied to benefit marine life. However,...

Numerical & experimental investigation on the effect of scour formation and protection on the monopiles behavior

Offshore wind farms are rapidly developing in Western Europe as an alternative means of clean energy. The foundation of wind-turbines in the shallow water of the Northern Sea is almost exclusively (over 87%) performed by short rigid monopiles, as an efficient and relatively cheap solution. Scour formation, meaning the soil removal around the...

The Impact of a Noise Mitigation Screen on the Scour Protection: Process identification and worst case evaluation

Current trends show that the offshore wind industry is evolving into deeper waters, with larger turbines and consequently larger foundations. In Europe 80% of the wind turbines are installed on monopile foundations and this is expected to be the dominant choice in the future. The shallow geology of most of the wind farms is characterized as sand...

Wood as a scour protection

In the light of the waterframework directive, the dutch organisation of rijkswaterstaat has decided to investigate the application of logs as a biological alternative for the protection and cover of both naturally developing scour holes. In this research a laboratory model was created that was designed to develop a scour hole by gradually...

Numerical Investigation on the Effect of Scour Formation & Scour Protection on the Stiffness & Lateral Capacity of Monopiles

Wind turbines are nowadays the main means for producing renewable energy in Northern and Western Europe, and therefore research is conducted to secure their efficiency. One of the critical aspects of the windfarms is the foundation type, as it can define the functionality and the cost of each turbine. Monopiles have prevailed as the most...

Stability of open granular filters under wave loading

A filter can be applied to protect a bed against scour. Normally, these filters are geometrically closed, to prevent winnowing of the base material through the filter. However, geometrically closed filters are expensive and difficult to realize in the field. Geometrically open filters can serve as an alternative. Within an open filter, the pores...

Evaluating Scour at Bridges - Fifth Edition

This document is the fifth edition of HEC-18. It presents the state of knowledge and practice for the design, evaluation and inspection of bridges for scour. There are two companion documents, HEC-20 entitled "Stream Stability at Highway Structures", and HEC-23 entitled "Bridge Scour and Stream Instability Countermeasures". These three documents...

Flexible scour protection around cylindrical piles

This research focuses on the behaviour of a granular scour protection around piles when the bed is subjected to bed degradation. Furthermore, engineering guidelines are provided to account for bed degradation in the design of the initial scour protection. To address the behaviour of the protection, a physical model is used and to obtain the...

Stability of toe and scour protection

Local scour can occur at a breakwater constructed on a sandy seabed and may endanger the overall stability due to sliding of the main armour layer if the toe and scour protection is failing. The scouring pattern is a function of the water depth, wave conditions, sediment characteristics, and breakwater configuration and reflection...