Engineering Services

Offshore wind projects are complex and long running. Strong engineering competencies are therefore required in all project phases to ensure the best and most appropriate project development throughout all project phases.

We provide contract and package management services for our clients as well as technical on-site supervision during cable, foundati­on and WTG installation and commissioning phases. Our experienced engineers provide technical assistance in areas such as quality management, document review, interface management, health and safety and environmen­tal management. Our approach to design combines extensive in-house expertise in hydrodynamics, geote­chnics and structural engineering. Using our extensive experience and innovative approaches, we can identify the best foundation type for a specific locations and purpo­ses.

Expertise in hydrodynamics, geotechnics and structural engineering

Our approach combines extensive in-house expertise in hydrodynamics, geotechnics and structural engineering. Using our extensive experience and innovative approaches, we can identify the best foundation type for a specific locations and purposes. We use in-house engineering design software which we continuously develop and test.

Examples of innovative projects in which NIRAS has participated

NIRAS offers development of detailed design of foundations for offshore wind farms where weather conditions are extreme. We can furthermore introduce damping systems with the aim to reduce fatigue and increase the life span of steel monopoles. In addition, we design monopiles with bolted connections between monopile and transition piece as well as integrated monopiles, where the transition piece is omitted. We ensure that both designs are combined with an optimised installation and operation procedure.

We conduct parametric studies of various floater concepts, where the knowledge obtained can be used to consider different floater concepts in early design phase where choice of concept has significant impact on the cost.

NIRAS is also a front runner in provision of hydrodynamic loads to a detailed concrete foundation design based on CFD calculations, certified by a leading certification company. We solve challenges within such tasks regarding verification of the model, through extraction of relevant results and inclusion of influence of the irregularity of the waves.

NIRAS furthermore possess experience within development of Design Basis, including design briefs, and performance of detailed design which includes:

• Geotechnical data interpretation and design profiles per foundation locations
• Natural frequency of WTG systems and OHVS system
• Extreme events
• Fatigue (installation and operational)
• FEM analysis of grouted connection
• Corrosion protection (surface protection, cathodic protection)
• Scour protection
• Ship impact
• Design of primary structures
• Design of secondary structures
• Design of provisional structures
• Design of elastomeric bearing system (provisional solution in case the vertical bearing capacity of the grouted connection should fail)
• Installation
• Dismantling
• Fabrication
• Operation and maintenance
• Quality control (fabrication and installation)

We are also experienced in developing alternative detailed designs with the purpose of minimising installation risks. This process includes:

• Development of a new design with elastomeric bearings, resting on the TP and the MP top edge, and serving as provisional back-up solution in case the grouted connection should fail.
• Design of an epoxy containment ring (ECR) to be established below traditional grout zone. The purpose of the ECR is to minimise the risk of the crushed grout being washed away. Once the epoxy has hardened, a traditional grout is injected on top of the ECR. In order to verify the flow pattern of the epoxy and that the epoxy has the required mechanical properties after curing, a full scale test of the epoxy injection is performed and evaluated.