Consultancy Arup will publish a report this spring on the use of seawater mixed grout connections using ordinary Portland cement (OPC) for jacket foundations at offshore wind farms as part of the Carbon Trust’s Offshore Wind Accelerator (OWA) programme.
The report aims to fill a gap in the underlying test data and designs in order to establish and verify the use of seawater-mixed grout.
The report has been commissioned by a group of offshore wind operators including Innogy, ScottishPower Renewables/Iberdrola, SSE, EnBW, Orsted, Statkraft and ORE Catapult under the OWA programme.
“The main objective was to develop a comprehensive database of large scale test results to extend and validate design guidelines for grouted connections with geometries relevant for pre-piled jacket structures,” said project director Daniel Bartminn.
The tests, carried out at KIT Karlsruhe, are the largest consistent series for large annuli in full and half scale and add “extensive knowledge to further improve existing ISO guidelines”, the companies said.
The data will be analysed in March and summarised in the Arup-authored report.
“We have particularly emphasised the verification of the use of seawater mixed OPC as it significantly reduces the environmental footprint for these structures. In contrast, high-strength grouts require freshwater, which offshore adds to the cost,” Bartminn said.
OPC grouted connections mixed with seawater technology have been used for some 100 offshore wind jacket foundations, including the 325MW Thornton Bank project in Belgian waters, the 150MW Ormonde project in the UK and Alpha Ventus off the German coast.
Image: Innogy
Trust targets jacket cement
By EBS