Introduction
GeoIntel’s client was a major transmission system operator (TSO) in Europe. GeoIntel has acted as the geotechnical expert for this project, supporting the client in offshore geotechnical investigations and laboratory testing for two offshore substations in Baltic Sea.
Since 2022, GeoIntel’s involvement has spanned site investigation (SI) planning and producing technical specifications, management of the advanced laboratory testing, and final technical review. The scope covers definition of laboratory test schedules (LTS), provision of test input parameters, and verification of results against international standards and project specifications, in addition to reviewing the deliverables from the geotechnical consultants, ensuring that the geotechnical dataset is reliable for offshore foundation design.
Figure 1 Project location in the Baltic Sea
Offshore Campaign Planning, Managing and Follow-up
During the initial phase, GeoIntel shaped the scope and structure of the offshore investigation by assessing available ground data and defining the required in-situ tests at each investigation location. Engineers evaluated borehole objectives to ensure that the selected test types and depths aligned directly with the foundations’ design requirements.
GeoIntel’s engagement during survey works enabled adherence to investigation objectives, verification of sampling and in-situ testing procedures, and timely identification of deviations from the agreed scope. This ensured that data and samples delivered to the laboratory were suitable for advanced testing and subsequent interpretation.
Advanced Laboratory Testing
GeoIntel audited the laboratory and defined procedures for the handling and storage of samples from the vessel to the onshore facility, ensuring that all samples met quality requirements before testing. After the soil classification tests, the laboratory conducted advanced testing, which included classification tests, effective stress tests, advanced tests such as Direct Simple Shear (DSS), cyclic tests, and more advanced tests such as Resonant Column..
GeoIntel defined input parameters, adjusted test sequences based on prerequisite results, and reviewed test results to ensure compliance with standards, project specifications and foundation design requirements.
Within the cyclic testing program, GeoIntel managed the tests from sample batching, all the way to assigning tests conditions to produce sufficient results, enabling the production of high quality cyclic contours for design.