Validation of wind turbine foundation design, and long-term monitoring

Geotechnical challenges mean that accurate design validation for the foundations of offshore wind turbines, and monitoring them long-term, requires strain measurements that are the most robust and cost-effective available. Here is how HBM can help.

Water and electricity don’t mix. So when measuring strain underwater and even beneath the soil line, particular care is needed to give strain measurement technology the best possible chance to survive. HBMs engineers can offer assistance in the design, installation and commissioning of measurement systems in such harsh environments. With a long track record in the offshore wind industry, it’s clear that three areas are particularly important to consider;

Choice of technology; HBM offers both electrical strain gauges and optical strain gauges, both backed by reliable temperature compensation measurements, all commonly used to aid design validation and provide long-term monitoring of structural health in offshore foundations. Optical strain gauges are becoming increasingly popular in this particular application. The inherent resistance of the fibre-optic measurement to water offers an additional layer of security, in addition to the total measurement system typically having much less cabling - saving mass, installation time and money. HBM can design the optimum measurement array to cover critical measurement hotspots.

Quality of installation; HBM regularly runs training courses on strain gauge installation and the performance of the gauges (both optical and electrical) are hugely influenced by the quality of the installation. Either bonded or welded, issues such as surface preparation, soldering and programming of the relevant DAQ make a big difference to the quality data you’ll get. HBMs engineers have, between them, hundreds of years experience in performing the highest-quality installation possible for foundations destined for the seabed. They also have the correct certification for working in the yard and offshore, to help with those important details and get you up and running.

Protective method; HBM has a proven method for protecting measurement points in the foundation of monopiles, jackets and gravity base structures used in the foundations of offshore wind turbines. Using carefully developed materials and following well-documented installation methods, our engineers will ensure that both electrical and optical gauges have the best chance of surviving the effects of piling, submersion in water, and the long-term geotechnical issues which can eat away at sensors offshore.