Piling & Vibro Equipment
P.O. Box 12529
5011 Vernon Road, Suite 2
Jacksonville, FL 32209,
T: (904) 765-6686
Vibratory pile driving – a serious alternative for offshore foundations
The offshore wind industry is about to start a new chapter. The industry is ready for innovations that drive piles into the seabed faster, cheaper and more carefully. Vibratory pile driving is the keyword.
A group of developers and operators of offshore wind farms – RWE Innogy, Bilfinger Offshore, DONG Energy, EnBW, E.ON and Vattenfall – joined forces and launched a pilot project to test the pile behaviour as a consequence of an alternative installation method for offshore foundations. The project is part of the Carbon Trust Offshore Wind Accelerator, a world-leading research and development programme for reducing the costs of offshore wind energy. During the test period a comparison is made between the conventional method of impact hammering versus the vibration of steel piles in a test environment on land. The goal of the test was to prove that vibratory piling can offer a faster and more environmental friendly method of installing steel foundations for offshore wind farms and to evaluate the method with regard to stability.
For this test, Dieseko Group delivered the PVE 500M vibratory hammer. This vibratory hammer has twelve huge mass eccenters and is developed for driving large piles with a diameter up to 4550 mm / 179 in. The PVE 500M is compact, so the total lifting height of pile and vibratory hammer is as small as possible. The vibratory hammer has a static moment of 500 kgm / 43,400 in-lbs., which makes it the largest single device on the market and develops the equivalent of over 1,000 Mt of force. In the test series, a crane placed the vibratory hammer onto the pile.
The test results are promising. On the test site, the vibratory pile installation method has shown significantly reduced peak noise emissions as well as installation time compared to a hammered installation. Vibration technique does not only work less noisy, the technique will eliminate the need for noise reduction measures, such as bubble curtains or noise insulating enclosures. This has a huge positive impact on the costs of offshore projects. Vibratory foundation can be controlled to produce a similar bearing capacity to impact hammered piles.
Finding innovative ways to reduce costs of pile installation will help to bring down the costs of offshore wind energy. This is important, because it will make the offshore wind industry competitive with conventional energy sources. According to the test, vibro techniques are a viable method for pile driving and also demonstrate what can be achieved through industry collaboration.