Monitoring of driven pile installation for 70 wind turbine bases

A multitude of sensors for ultra-accurate data

Monitoring of pile installation required the offsets between all sensors to be defined with dimensional control techniques during the quayside sensor installation. A full onshore trial of the pile adjustment and monitoring systems was also done prior to mobilisation. 

To support the extensive operation, UTEC engineered a robust instrumentation system to monitor pile installation with exceptional precision. Multiple independent, calibrated sensors were used to ensure resilience against shock loads from the pile hammer. Pile inclination and separation were tracked using ram measurements and inclinometers, while a fibre-optic gyrocompass provided heading and attitude data. Cameras recorded laser lines on depth scales to measure driven depth, referenced to the seabed via altimeters. Additional depth data came from pressure sensors on the hammer and seabed, adjusted for seawater temperature and density. This multi-sensor approach ensured accurate, real-time monitoring throughout the piling process. 

Innovations in action

To manage the large number of video and data lines from the various sensors, we designed and built a subsea multiplexor for data transmission to the installation vessel, where UTEC specialist and bespoke iSite software combined the various data into live graphic displays of the PTT and piles. 

Comparing the data between the sets of sensors during piling enabled the measurements to be corrected for the bending of the steel structure connecting the towers, improving accuracy. 

The result 

UTEC provided €2 m of specialised equipment, software and personnel to support the installation of seventy sets of piles – all to the accuracy needed for turbine installation. The integration of the monitoring with the template design and driving of piles, performed by Acteon’s marine Foundations business line, provided a streamlined and efficient solution to the customer.