Design

NIRAS offers design consultancy from the early conceptual phase to the final detailed design. We have extensive experience in choosing the best foundation type for a specific site and are fully up to date of well proven and innovative solutions. Our design is based on in-house software which has been developed during the years.

Structural design

NIRAS offers conceptual and detailed design of:

• Gravity based concrete foundations for wind turbines. Our latest detailed design is the newly opened Sprogoe offshore wind farm.
• The well known steel monopile for wind turbines and metrological masts. 
• Foundation structures and layout planning of transformer stations. 
• Design of metrological masts including consultancy of appropriated measuring equipment. 
• Design of jacket foundation in collaboration with selected associates. 
• Secondary structures.

Sea bed design

In extension to the geotechnical design we also conduct the sea bed design. For the gravity based foundation structure we optimise the foundation depth, the amount of sub soil to be excavated and the type of stone bed base used for basement for the foundation.

In the sea bed design we have focus on:

• Sea bed mobility in order to for instance take sand waves into account in the design
• Scour protection for preventing uncontrolled stability failure of the foundation structure and for protection of cables

An optimal sea bed design minimises offshore works and optimise the construction quantities

Innovative projects

NIRAS has participated in several development projects concerned with optimising existing design and developing new structure types. The following projects can be highlighted:

• A new concept for pre-stressed concrete foundation in which both pre- and post tension is used to achieve highly reduced crack size and thereby reduce maintenance costs. The project was carried out in collaboration with the Danish company SPAENCOM.
• In connection with the Carbon Trust project NIRAS introduced a damping system in order to increase the fatigue life of steel monopiles.
• A Research and Development project was conducted in relation to the development of the design of the suction buckets used for foundations.