Foundation of an offshore structure

Patent metadata

Field	Value
Publication number	US-9976273-B2
Application number	US-201515519131-A
Country	US
Kind code	B2
Filing date	Oct 12, 2015
Priority date	Oct 14, 2014
Publication date	May 22, 2018
Grant date	May 22, 2018

Abstract

A foundation system for the foundation of an offshore structure includes a monopile having an anchoring portion anchorable in a seabed and a connection portion disposed at the opposite end. A platform structure is connected directly to the connection portion of the monopile or indirectly via a transition piece. The platform structure is disposable above a water surface. The foundation system includes at least two stabilizing devices connected directly to the platform structure or indirectly to the platform structure via the transition piece. The stabilizing devices are attachable to the seabed such that tensile forces or compression forces are transmittable between the seabed and the platform structure. Securing points on the stabilizing devices, together with the connection portion of the monopile, define a plane having a horizontally extending component.

First claim

The invention claimed is:

1. A foundation system for the foundation of an offshore structure, comprising:
a monopile, having an anchoring portion anchorable in a seabed, and having a connection portion disposed at an end opposite the anchoring portion; and
a platform structure configured for connection at least one of directly to the connection portion of the monopile and indirectly via a transition piece, wherein the platform structure is disposable above a water surface, the foundation system comprising:
at least two stabilizing devices configured for connection to at least one of directly to the platform structure and indirectly to the platform structure via the transition piece, wherein the at least two stabilizing devices are attachable to the seabed, such that at least one of tensile forces and compression forces are transmittable between the seabed and the platform structure, wherein the stabilizing devices comprise securing points, wherein, together with the connection portion of the monopile, the securing points define a plane having a horizontally extending component.

2. The foundation system of claim 1 , wherein the at least two stabilizing devices are each stabilizing pillars configured for displaceable connection to at least one of the platform structure and the transition piece, wherein the at least two stabilizing devices are lowerable onto the seabed from at least one of the platform structure and the transition piece; and the stabilizing pillars are configured to lock to at least one of the platform structure and the transition piece, such that axially oriented compression forces are transmitted thereby to the seabed.

3. The foundation system of claim 1 , wherein the at least two stabilizing devices are configured for connection to the seabed, such that tensile forces are transmitted thereby to the seabed.

4. The foundation system of claim 1 , wherein the at least two stabilizing devices are each flexible, tensile elements configured for connection to the seabed.

5. The foundation system of claim 4 , further comprising a plurality of foundation piles equal in number to the tensile elements, wherein the plurality of foundation piles each comprise a drop anchor connectable to one of the tensile elements, and wherein each drop anchor comprises a column of grouting compound, poured in situ, having a length within the seabed.

6. The foundation system of claim 5 , wherein the drop anchor further comprises a mechanism that, when activated, liquefies the seabed in close proximity to the drop anchor, to assist with penetration of the drop anchor into the seabed.

7. The foundation system of claims 4 , further comprising a tensioning device configured to apply a force to the tensile elements when the tensile elements are connected to the seabed.

8. The foundation system of claim 1 , wherein the platform structure comprises a transformer substation facility.

9. An offshore structure, comprising the foundation system of claim 1 , wherein the offshore structure is positioned on the monopile and the at least two stabilizing devices are connected to the seabed.

10. A method for installing a foundation of an offshore structure, comprising:
providing a monopile having an anchoring portion anchorable in a seabed and a connection portion disposed at an opposite end;
providing a platform structure connectable to at least one of directly to the connection portion and indirectly via a transition piece wherein the platform structure is disposable above a water surface;
anchoring the anchoring portion in the seabed;
disposing the offshore structure on the platform structure;
providing at least two stabilizing devices that are connectable at least one of directly to the platform structure and indirectly to the platform structure via the transition piece and that are contactable with the seabed such that at least one or tensile and compression forces are transmitted between the seabed and the platform structure, wherein, when the foundation system is in the installed state, securing points of the at least two stabilizing devices, together with the connection portion, define a plane having a horizontally extending component; and
bringing the stabilizing devices into contact with the seabed.

11. The method of claim 10 further comprising
providing and disposing a drop anchor at a predefined height above the seabed;
fastening a tensile element to the drop anchor;
fastening a grouting-compound line to the tensile element;
dropping the drop anchor, such that it penetrates the seabed; and
feeding a hardenable grouting compound into an injection channel produced by the drop anchor upon penetration of the seabed.

Assignees

• Innogy Se

Inventors

• Bartminn Daniel

Classifications

• E02B2017/0065

  Monopile structures · CPC title

• E02B17/02

  placed by lowering the supporting construction to the bottom, e.g. with subsequent fixing thereto · CPC title

• E02D27/425

  specially adapted for wind motors masts (wind motors per se F03D1/00) · CPC title

• E02D5/32

  with arrangements for setting {or assisting in setting} in position by fluid jets {(placing piers by using fluid jets in general E02D7/24)} · CPC title

• E02D5/24

  Prefabricated piles · CPC title