NGI's specialist expertise
- the strength and deformation characteristics of sediments under cyclical loading
- optimal foundation engineering solutions
- the combination of geological, geophysical and geotechnical knowledge, used for example to assess geohazards
Since the start of Norwegian oil and gas activities, NGI has built up comprehensive expertise in offshore geotechnics. Instrumented monitoring has provided valuable information and verification of how offshore platforms and installations behave during day-to-day operations.
Steel platforms have traditionally been founded on piles driven to great depths, while gravity base platforms in concrete (GBSs) are founded on skirts (foundation walls) that penetrate far down into the seafloor. Experience from GBSs is used today in the foundation engineering of large LNG receiving terminals located off the coast, and for foundation engineering for offshore wind turbines.
The installation of circular skirts using negative pore pressure (suction) led to the development of bucket foundations as an alternative to piles, and later to suction anchors used to secure floating platforms.
Research and development
The challenges and NGI's research in offshore foundation engineering are currently concerned With:
- software development - for example calculation of the holding capacity of skirt foundations/suction anchors, soil structure interaction
- model testing and behaviour of pipelines and flexible pipes in soft clay
- decommissioning and relocation of offshore installations
- geotechnical aspects of offshore wind farms
- new challenges from greater sea depths with softer sediments