The specification of both geophysical and geotechnical surveys for offshore developments is key to ensuring your future asset is suitably managed from a risk perspective. Typically a geophysical survey is used to define the seabed and sub-seabed conditions across the site before performing the subsequent geotechnical survey. It is essential that the geophysical survey is properly designed in order to define the site conditions, such as bathymetry, seabed slope and spatial geological variation. The geotechnical investigation is usually dependent upon the geophysical survey findings and planned subsea infrastructure but equally, it is also reflective of the anisotropy of the geological conditions as determined by the geophysical survey. Cathie Associates have considerable experience in producing investigation specifications in full compliance with the most recent guidelines including:

  • Guidance notes on Geotechnical Investigations for Subsea Structures (Offshore Soil investigation Forum, 2000)
  • Guidance Notes on Geotechnical Investigations for Marine Pipelines (Offshore Site Investigation and Geotechnics Committee)
  • Guidance Notes on Site Investigations for Offshore Renewable Energy Projects (Offshore Site Investigation and Geotechnics Group)
  • Guidance Notes for the Planning and Execution of Geophysical and Geotechnical Ground Investigations for Offshore Renewable Energy Developments (Offshore Site Investigation and Geotechnics Committee)
  • Norsok Standard, Marine Soil Investigations, G-001 Rev 2, October 2004
  • Federal Maritime & Hydrographic Agency (BSH), Standard – Ground Investigations for Offshore Wind Farms, 2008.
  • Det Norske Veritas (DNV), Classification Note 30.4, February 1992;

In addition, Cathie Associates also actively review and contribute to new guidelines such as the latest ongoing revisions to the OSIG guidance for ground investigations for offshore renewable energy developments.