LEIDEN, the Netherlands – DNV GL has awarded Heerema statements of feasibility on the silent foundations the company is developing with the University of Dundee.
It is developing pile foundations for offshore structures that can be installed without loud hammering, which can be harmful to marine life and requires noise mitigation systems that produce a considerable CO2 footprint.
The concepts being investigated are helical or screw piles and so-called push-in piles.
The helical pile foundation suits foundations that require shallow penetration in the seabed. The pile has a helical blade at its tip rotated during installation to allow the pile to penetrate the soil. This concept includes a moment arm that will connect to one of Heerema’s vessels to provide the required reaction force. Also, this pile is prepared for the future as by reversing the process. The company said it can use it for removing foundations allowing low-cost decommissioning and full recycling or re-use of piles.
The push-in pile design replaces a traditional single open tubular pile with a cluster of four smaller diameter open tubular piles. According to the company, this design can eliminate noise pollution as it requires no pile-driving or hammering. Instead, after some strokes, each of the piles is pushed into the soil with two or three providing the uplift resistance required to push in the fourth.
As part of a technology qualification process, the results were discussed with DNV GL, and several workshops were conducted to review the foundation concepts and the development results. The statements of feasibility are the first formal step toward qualifying these technologies for actual use in offshore structures, the company said.