On the former Zuiderzee, the IJsselmeer, construction works for the monopile foundations have been completed by Consortium Zuiderzeewind (Van Oord Offshore Wind and Siemens Gamesa Renewable Energy) for the largest wind farm within inland water in the world. The wind farm comprises 89 turbines of 4.3 MW each. These turbines will be founded on 89 monopiles. The monopiles have a diameter of 4.5 m, and a length varying from 30 to 40 m.
Allnamics has monitored the pile installation process, recording the hammer blows during pile driving (PDA). Sensors for strain and acceleration were mounted on the inside of a number of piles. No WiFi or cable connection with the sensors is possible from the inside of the pile to a monitoring computer on deck. Consequently, the Allnamics PDR data acquisition system has been set in the ‘data recorder mode’ (stand-alone monitoring). The response to every hammer blow was stored in the internal data memory.
After installation, the PDR was removed from the pile, and the data was recovered to be analyzed: e.g. for determining stress levels in the pile to assess potential installation effects on fatigue life and static soil resistance at the end of driving (EOD).
The wind farm will be operational in 2021. With a total maximum capacity of 382.7 MW, Windpark Fryslân will supply enough energy for approximately 500,000 households.
More information can be found on the website of Windpark Fryslân: