For further development of the patented method in 2021 a grant of €1.8 mln is offered from the Dutch government (project SIMPLE II[1], budget €2.75 mln). In addition, GBM Works has been invited to participate in the SIMOX project set up by the GROW offshore consortium[2].
In the coming period the attention of the organization will be focused on potential partners that stand for design and/or implementation of offshore wind energy projects where noise levels during installation are limited.
Last year GBM Works executed tests on a silent installation method (project SIMPLE I) which proves to drive 4 times faster and 2 times deeper than the traditional vibration solution, while noise levels will drop dramatically compared with current hammering, and at significant lower level than with already more silent vibration hammering without compromising the lateral bearing capacity.
The new method
The new method is based on a combination of two principles:
controlled fluidization of the soil within the monopile and
vibrating the pile with an integrated vibratory hammer.
In this way the soil resistance is removed which normally prevents the penetration of the pile into the soil. The machine GBM Works is developing for the respective principles are called the Vibrojet.
The test results
This new foundation method was tested Q3 2020 at the Maasvlakte and compared with traditional installation methods at a 1:4 scale. The results are very convincing:
1. In addition to significant reduction of noise levels, the Vibrojet installation technology of GBM Works proves to install 2x deeper and 4x faster, performances that make the construction of wind farms more environmentally friendly, but also much more efficient and therefore cheaper.
2. The construction of wind farms is an expensive business, and once at sea, costs quickly mount up if unexpected issues arise. The simulation model validated by GBM Works based on extensive lab and field tests provides an accurate prediction of penetration depth, penetration speed and the required machine settings.
3. By measuring the strain in the monopile itself, an indication has been drawn on both sound emissions and fatigue generated by the compared installation methods. Based on these performance indicators, one can conclude that significant reduction can be expected using the Jet-gun of the Vibrojet.
4. Ultimately GBM Works wants to introduce the Vibrojet technology which enables to transmit vibrations at the low end of the pile. A dummy tool has successfully brought down to the bottom of the pile and lifted again after installation at target depth. It proves that risks like clogging and rapid segregation can be overcome.
Using GBM Works’ jetting technology in combination with the existing vibration technology contractors reduce their installation time, their risk not reaching target depth, can eliminate costly mitigation measures and can potentially avoid over-dimension of the piles to compensate for fatigue.
Main developments in the market
To reduce nuisance, many governments are announcing restrictions on noise levels, a good trend. Contractors now mostly work with noise reduction measures, such as bubble screens, to reduce the noise generated underwater by pile driving. These measures cost a lot of money and time.
It is expected that wind turbines will become larger and larger. Equipment suppliers face limitations on powerpacks and available space on board of vessels in the near future.
GBM Works offer to the market
GBM Works' installation technique and predictive modeling helps the industry protect the environment and reduce construction costs.
Based on GBM Works’ technology, a first proto-type machine will be produced this year. With the simulation models developed, GBM Works already can predict installations at sea on different soil types the most efficient and environmentally friendly way.
It is foreseen that with the knowledge GBM Works gained, it will be possible to execute the technology already on smaller project near shore, and during decommissioning of structures.
GBM Works is happy to receive interested parties physically or virtually at its headquarters and laboratory testing facilities in Utrecht, in the former power plant of Eneco, one of its business supporters.
We would like to get in touch with parties for whom our technique, prediction models or knowledge could be of value in projects or studies. In particular, we are looking for opportunities to demonstrate our technique through a full-scale pilot project at sea.
[1] SIMPLE II, under leadership of GBM Works, with Deltares, DEME Offshore and Barth Machinefabriek as project partners in a consortium
[2] SIMOX, under leadership of Delft Technical University, in which several companies participate actively involved in offshore wind energy, such as Boskalis, van Oord, Seaway7, SIF, Deltares, RWE, Siemens Gamesa, IHC IQIP and Cape Holland.
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