Improved ground stiffness measurements for offshore wind turbine

The UK is the world leader in offshore wind energy and has set a new ambitious target of 40GW of wind power by 2030, producing enough offshore wind capacity to power every home. Offshore wind turbine (OWT) foundations make up a significant portion of the capital cost of a project and optimisation of their design is paramount. Recent research has led to significant advances through theoretical developments combined with high-quality field-testing. There remains significant uncertainty in the measurement and interpretation of key soil and rock deformation parameters that underpin design approaches. Improving offshore site characterisation will contribute to economising foundation geometries, lowering OWF capital costs and meeting the UK's renewable energy targets.
A new programme of research in the School of Engineering aims to quantify and reduce the uncertainty associated with soil/rock in situ stiffness measurements and minimise the impact on the predictive capability of OWT foundation design methods. This will be achieved through rigorous measurement and interpretation in the field and the laboratory. This PhD project will use advanced laboratory testing combined with analysis of large industry offshore site investigation datasets to investigate intra- and inter- method variability between laboratory methods to determine both small strain stiffness and stiffness degradation and improve correlation with in situ measurements. The successful student will be involved in the commissioning and use of a new resonant column device within the geotechnical laboratory, funded by Vattenfall Wind Power. There may also be an opportunity for the PhD student to undertake fieldwork within the UK. The research outcomes will be applied to design with an opportunity to reanalyse designed monopile foundations and determine the effect of the results on design life.