Vibratory Pile Driving Researchers Go Deeper Underground (Gallery)

innogy-led research project to test a new method of installing foundations on offshore wind farms has entered its next phase.

In 2014, six 21-metre piles, each more than four metres in diameter, were hammered and vibrated into the ground at an excavation pit in Altenwalde near Cuxhaven.

“In the test environment two and a half years ago, the vibratory method was up to ten times faster and, in the light of certain installation criteria, proved to have a load-bearing capacity comparable to conventionally driven piles, as well as lower peak noise emissions – which is particularly important for protecting marine mammals,” said Artur Czarnecki, project manager at innogy SE.

“Yet we also wanted to collect additional data in order to further develop this alternative installation method in view of actual conditions on the open sea.”

The existing piles were therefore driven even deeper into the ground last weekend. The goal was to compare the resistance now with that measured immediately after the initial installation, thereby documenting additional load-bearing capacity in the foundations resulting from so-called adhesion effects. The collected data will be evaluated in coming months. The final results are expected within a year.

“We have successfully completed the test series. Now we have to carry out a detailed analysis of the data we recorded. The data are very promising in terms of potential savings. This test has allowed us to take a major step forward toward actually using the vibratory process on the open sea,” Czarnecki said.

Apart from innogy SE who is leading the project, other partners include E.ON, Iberdrola and the Carbon Trust Wind Offshore Accelerator. The project is publicly funded by the Scottish government.

Photos: innogy SE