DE102011052700A1 - Method for settling gravity or shallow foundations of e.g. sea energy installation, on bottom of sea, involves unchanging part of foundation, where foundation is used for readjustments of wind turbine - Google Patents

Abstract

The method involves lowering foundation (4) upto height such that up and down movements are produced in waves without disturbing current beneath the foundation, where the foundation stirs up a sea floor. The foundation is settled on bottom of sea (2) by joggle devices supported on the bottom of the sea. The joggle devices are slowly lowered to an end position of the foundation to be reached. A part of the foundation is unchanged and used for readjustments of a wind turbine. An independent claim is also included for a joggle device.

Description

Technical area

The invention relates to a method and a device for the soil-friendly settling of flat or gravity foundations of wind turbines, but also flow energy plants, on the seabed.

State of the art

Typical offshore wind turbines have a foundation, a mast and a gondola with rotor. Even current power plants on the seabed have a, albeit less large, foundation.

Offshore wind turbines must be able to survive extreme weather events. Especially offshore, high demands are placed on the plants, where above all the moving water exerts the main forces.

For offshore foundations, various types are known in the art, e.g. the monopile, the jacket foundation, the tripod, the gravity foundation or the flat foundation and combinations thereof. Flat and gravity foundations have the advantage of requiring no complicated drilling or piling and in principle to be displaced or dismantled.

Setting up on the seabed requires elaborate preparation of the ground under the foundation, in order to ensure the permanent uniformity of the foundations and thus of the plant above them. In order not to change the elaborately prepared soil, moreover, the foundation may be lowered only very slowly, so that no vortexes arise that rinse the previously elaborately prepared soil under the foundation again. Also, too fast and thus hard landing of the foundation on the seabed could lead to damage to the overall structure of the wind turbine or the power plant.

In order to ensure a slow, even touchdown of the heavy foundations on the seabed, even in clear seas (2 meters wave height), ships are planned or built with very complex control and regulating mechanisms. This makes the ships extremely expensive! At the same time, due to the enormous size of the installations, the complex precise control and regulation means that these ships can not be adapted to a wide range of types and sizes of wind energy or flow energy plants.

In addition, the exact preparation of the seabed requires extra time specifically designed for this purpose expensive machines.

Object of the invention

The object of the invention is to settle flat or gravity foundations of wind or turbines precise and cost on the seabed can.

Furthermore, the invention should optionally also provide the possibility of a simple subsequent readjustment of the foundation, if this should have left their desired position by extreme events (tsunami, storms) or under-flushing or if the seabed should be inaccurate or not prepared.

Presentation of the invention

The object is solved by the features specified in the characterizing part of claim 1.

The settling process is subdivided according to the invention into (at least) two separate steps:
For this purpose, the invention provides not settle the foundation directly on the seabed, but first on a located between the actual foundation and the (preferably prepared) seabed, preferably lower elastically yielding, standing in ground contact device.

This allows a relatively quick lowering without complicated control and regulation! This lowering can be done by very simple ships (also unmanned barges).

The actual settling of the foundation then takes place, uncoupled from the ship, by simple mechanical means such as motors, interlockings, hydraulics, pneumatics, levers, threads or other methods, as known in the art for the slow lowering of heavy weights. These simple mechanical aids then reduce the foundation independently and largely unaffected by wave movements of the sea on the intended foundation surface on the seabed.

General: The foundation will not be lowered down to the bottom of the sea in one operation, but the process will be carried out in at least two steps, with the previous step providing for lowering to an intermediate height above the seabed and the later step lowering the foundation through on the seabed Seabed supported devices that are part of the foundation or releasably attached to the foundation.

The devices which temporarily support the foundation after the first step of settling the foundations at an intermediate height above the seabed and then settle them gently on the seabed are referred to below as bottom struts.

The Bodenabsetzvorrichtungen can be built-in part of the foundation itself and remain in this after the settling process or they can be designed so that they are connected only during the settling process with the foundation and can be subsequently separated from this and reused. The settling itself is done by a part of the settling device, the settling mechanism.

The lower the intermediate height at which the foundation is held by the Bodenabsetzvorrichtungen after the first step of the settling, the weaker and thus much cheaper they can be carried out!

Therefore, it is advantageous to settle the foundation as far as possible near the ground on the Bodenabsetzvorrichtungen.

(However, it is of course also possible to lower the foundation with the help of bottom settlers from above sea level.) To allow a relatively fast lowering as far as possible near the ground, without creating turbulent currents that would stir up the soil, it is advantageous if the foundation is aerodynamically shaped despite its large volume. The shape of the foundation should therefore have a low C _W value in the direction of movement of the settling.

The intermediate height is at least 0.5 meters. It is also dependent on the waves! High waves of e.g. 2 meters from Wellenberg to Wellental leads to constant periodic increases and decreases of the foundation by about 2 meters during the first step of the settling process. With such high waves, it is thus possible to determine e.g. the minimum height of these 2 meters plus a safety margin and the minimum height that must be present so that the seabed is not over-whirled up by the whirls during the settling process.

As a safe intermediate height, therefore, in many cases at least 3 meters above the seabed. For such and even greater intermediate heights can Bodenabsetzvorrichtungen for the often several thousand tons heavy foundations still very cost-stable build. This is especially true for those who are constantly reused.

• 1.) Bodenabsetzvorrichtungen, die dauerhafter Bestandteil der Gründung sind: Diese haben den Vorteil, daß sie es gestatten, an der Gründung jederzeit Nachjustierungen vornehmen zu können, z.B. auch nach Schiefstellungen derselben durch Extremereignisse wie Tsunamis, Orkanen oder Kollisionen mit Schiffen. Solche Bodenabsetzvorrichtungen haben weiterhin den Vorteil, auch Absetzungen auf wenig oder sogar unpräpariertem Meeresboden vornehmen zu können, da Unebenheiten über einen sehr weiten Bereich ausgeglichen werden können. Die Absetzvorrichtungen weisen an ihrer Unterseite hierzu besonders große Bodenaufstandsflächen (Pratzen) auf, die das Gewicht der Gesamtanlage dauerhaft tragen. Für den Fall, daß nur eine temporäre Abstützung nötig ist, können die Aufstandsflächen/Füße hingegen deutlich kleiner ausgeführt werden, weil nach Beendigung des zweiten Verfahrensschrittes, des Absetzvorganges auf dem Meeresboden, die Last von dafür vorgesehenen Flächen an der Unterseite der Gründung übernommen wird.

(Of course the wave height does not exactly determine the vertical deflection of the muzzle at the first lowering.) The wave height is not identical with the vertical deflection of the ship, because the vertical deflection is strongly dependent on the size of the ship and therefore usually much smaller than the wave height This also makes the vertical movement of the foundations above the seabed much lower!)

• 1.) Floor settlers, which are a permanent part of the foundations: These have the advantage that they allow to make at the foundation at any time readjustments, for example, even after misalignment of the same by extreme events such as tsunamis, gales or collisions with ships. Such Bodenabsetzvorrichtungen also have the advantage of being able to make deductions on little or even unprepared seabed, as unevenness can be compensated over a very wide range. The settlers have on their underside for this purpose particularly large ground contact surfaces (claws), which carry the weight of the entire system permanently. In the event that only a temporary support is necessary, the footprints / feet, however, can be made significantly smaller, because after completion of the second step, the settling process on the seabed, the load is taken from designated areas on the bottom of the foundation.

The Bodenabsetzvorrichtungen may be located laterally attached to the foundation, but preferably they are located in their interior and as far away from the center of the foundation (edge area).

One possible embodiment is tubular punches that move in sealed cylinders as a guide tube / channel. The punches represent the legs (or parts of the legs) of the settling device, on which the foundation in step 1 is sold. The cylinder contains (at least) a fluid which is then slowly discharged from the cylinder into a storage vessel or the seawater to lower the foundation in step 2.

One possible embodiment of this embodiment has a gas (preferably air) inside the cylinder (possibly together with water, whereby the air forms an air cushion above the water). The air acts as a gas spring when placing the settling device on the seabed, which leaves the stamp the ground contact, while the foundation is lowered even further to the intermediate level. In this way, there is no sudden touchdown the foundation and thus not too strong shocks on the foundation and the whole plant.

The cylinders can also be filled only with seawater and be open as long as the foundation is still attached to the ship. At the moment of uncoupling, the cylinder space is then closed and the practically incompressible water contained therein stiffens the cylinder so that it supports the foundation decoupled from the ship.

Instead of water, a liquid of higher viscosity is advantageous, because the requirement for the quality of the seal is significantly lower! For this purpose, water is preferably mixed with a water-soluble thickener. The thickener is preferably biodegradable, so that the liquid can be discharged into the water when lowering the foundation on the seabed.

Stamp and cylinder need not be round in cross section. The cross section may also be angular (e.g., rectangle).

The punches and cylinders have a height of 2 to 10 meters for many applications.

• 2. Bodenabsetzvorrichtungen, die nur vorübergehend Bestandteil der Gründung sind: Diese Bodenabsetzvorrichtungen werden nach Beendigung des Absetzvorganges von der Gründung gelöst und können dann für das Absenken weiterer Gründungen verwendet werden.

A decoupling of the founding of the ship is advantageously carried out at the moment (or timely) the highest increase in the foundations above the seabed when it "commutes" around its intermediate height.

• 2. Floor-levelers, which are only part of the foundation for a short time: These floor-leveling devices are released from the foundation after the settling process has ended and can then be used to lower further foundations.

Preferably, such settling devices are located laterally next to the foundation, because they can be easily removed from there. Preferably, they engage in laterally located at the foundation holding devices.

It is also possible, however, that from the settling device e.g. Grasp beams / trusses under the foundations and be pulled out again after completion of the settling process.

A possible embodiment of such a settling device in the case of a flat foundation in the form of a cross ( EP 1 691 073 A2 ) provides, for example, lattice structures / lattice towers detachably attached to the ends of the cross.

The grid structures have on their underside on a stand area outside the later base of the foundation. On the side of the grid structures is the settling mechanism, which brings about the lowering of the foundation in the second process step from the intermediate height to the seabed down.

For many applications, these grid structures are between 2 and 10 meters high.

Instead of laterally mounted lattice structures and laterally releasably attached to the foundation punch and cylinder are conceivable in another embodiment of the invention.

A decoupling of the founding of the ship is also in this case advantageously in the moment (or timely) the highest increase in the foundations above the seabed, when it "commutes" around their intermediate height.

The process step 2, the settling on the seabed, can take place while the ship is still on site. Preferably, however, the ship moves away from the foundation to be set off to a safe distance and method step 2 is controlled from there (cable or wireless control). With wireless control, the ship may even be heading home or to the next whereabouts if several foundations are on board.

The settling on the seabed does not have to be done by the same mechanisms that served to cushion it! There are separate, also different than hydraulic working, settling mechanisms used (for example, screws in thread).

The inventive method and its means are not limited to foundations, which are brought by ship to the Absenkort, but are also applicable to foundations that are self-floating brought in place and lowered there.

Furthermore, it is advantageous if the settling device consists of parallel smaller units, so that the failure of a unit does not lead to failure and especially not to security problems. In addition, several smaller units (such as punches and cylinders) can often be made more cost-effective and at the same time more stable than a large one!

• – solche ohne Absetzvorrichtungen, die eingesetzt werden, wenn kein oder kaum Wellengang besteht;
• – solche mit relativ kleinen Absenkvorrichtungen, die bei geringen Wellenhöhen eingesetzt werden;
• – solche mit größeren Absenkvorrichtungen, die bei starkem Wellengang eingesetzt werden.

Not always dominate wave conditions that require lowering by means of the described lowering devices. It therefore makes sense to always have foundations of various kinds to choose from:

• - those without settlers, which are used when there is no or hardly any waves;
• - those with relatively small lowering devices, which are used at low wave heights;
• - those with larger lowering devices, which are used in strong waves.

For the same reason, it makes sense to stock reusable Bodenabsetzvorrichtungen different sizes.

The figures show sketchy examples:

1 shows from the side viewed a flat foundation according to the prior art of EP 1 691 073 A2 which is suitable for the application of the invention. Other forms of foundation, in or on which the Bodenabsetzvorrichtungen can be attached, but of course deducted by the invention on the seabed!

2 shows the same state of the art, but in supervision. It is a cross-shaped flat foundation with claws that sit on the seabed.

3 shows the case of such a cross-shaped flat foundation, wherein in the ends of the cross stamp-shaped Absetzmechanismen 10 are included. This flat foundations are easily readjusted.

4 shows the case of 3 viewed from the side.

The settling mechanisms contained in the cross ends 10 put together from a stamp 10b respectively. 10c and a guide channel / tube 10a for the stamp 10b respectively. 10c ,

Inside the guide tube 10a There is a liquid or a gas or both. By means of this fluid can exert pressure on the stamp and thereby move the punch in the guide tube or cushion when placed on the seabed.

For the stamps are in the 4 two variants indicated: stamp 10b is closed at the top, stamp 10c however, is hollow and thus also contains fluid, which may act as a shock-absorbing example. Stamp c therefore acts softer when placing the foundation on the seabed.

• – Am linken Kreuzende ist eine Variante dargestellt, bei der sich zwei Absetzmechanismen 11 unter einer Traverse 13 befinden, die sich oberhalb des Kreuzes 5 befindet und von seitlich am Kreuz 5 lösbar angebrachten Haltestrukturen 12 an Ort und Stelle gehalten wird. Die Absetzmechanismen 11 (bzw. beinartige Fortsetzung derselben nach unten) reichen bis zum Meeresboden hinab und weisen daher dort vorzugsweise einen (nicht dargestellten) flächigen Fuß auf, der das Einsinken vermindert. Nach Beenden des Absetzvorganges werden die Haltestrukturen 12 vom Kreuz 5 gelöst und die Gesamtstruktur 11 + 12 + 13 kann nach oben abgehoben werden und für eine nächste Gründung wiederverwendet werden.
• – Am rechten Kreuzende ist eine Variante dargestellt, bei der sich zwei Absetzmechanismen 11 unter einer Traverse 13 befinden, die sich oberhalb des Kreuzes 5 befindet. Unter dem Kreuzende 5 (aber nicht unter der Pratze 7) befindet sich eine weitere Traverse 15. Die Traverse 13 und die Traverse 15 werden durch Verbindungsstrukturen 16 verbunden, so daß das Kreuz 5, auf der Traverse 15 ruhend, auf dem Meeresboden abgesetzt werden kann. Die Absetzvorrichtungen 11 (bzw. beinartige Fortsetzung derselben nach unten) reichen bis zum Meeresboden hinab und weisen daher dort vorzugsweise einen (nicht dargestellten) flächigen Fuß auf, der das Einsinken vermindert. Nach Beenden des Absetzvorganges wird die Traverse 15 von den Verbindungsstrukturen 16 gelöst und verbleibt am Ort (und kann dann für spätere Anhebevorgänge wiederverwendet werden) oder wird seitlich unter dem Kreuz 5 herausgezogen/herausgeklappt und die Gesamtstruktur 11 + 12 + 16, bzw. 11 + 13 + 16 + 15 kann nach oben abgehoben werden und für eine nächste Gründung wiederverwendet werden.
• – Zwischen oberem und unterem Kreuzende ist eine Variante dargestellt, bei der eine Gittermaststruktur 14 mit Längs- und Querstreben das (in diesem Falle gesamte) Gründungskreuz 5 seitlich und oberhalb einfaßt, wodurch eine steife Tragestruktur entsteht, an der das Gründungskreuz über Haltestrukturen 12 lösbar befestigt ist. Nach dem Absetzen der Gründung auf dem Meeresboden wird das Kreuz 5 von den Haltestrukturen 12 gelöst und die Gesamtstruktur 14 + 13 + 12 + 11 wird vom Gründungskreuz entfernt. Dies geschieht entweder durch Abheben über den höchsten Punkt 8 der Gründung hinaus oder die Gittermaststruktur ist, anders als in der Figur, seitlich offen oder zu öffnen und kann dann mit den daranhängenden Teilen 13, 12 und 11 seitlich abgezogen werden.

5 shows from above the case of a cross-shaped flat foundation with several variants outside the cross 5 attached settling mechanisms 11 ,

• - At the left end of the cross a variant is shown in which two settling mechanisms 11 under a crossbar 13 located above the cross 5 located and from the side of the cross 5 detachably mounted holding structures 12 is held in place. The settling mechanisms 11 (or leg-like continuation of the same down) reach down to the seabed and therefore there preferably have a (not shown) flat foot, which reduces sinking. After completion of the settling process, the holding structures 12 from the cross 5 solved and the forest 11 + 12 + 13 can be lifted upwards and reused for a next founding.
• - At the right end of the cross a variant is shown in which two settling mechanisms 11 under a crossbar 13 located above the cross 5 located. Below the cross 5 (but not under the claw 7 ) there is another traverse 15 , The traverse 13 and the traverse 15 be through connection structures 16 connected so that the cross 5 , on the traverse 15 resting, can be deposited on the seabed. The settlers 11 (or leg-like continuation of the same down) reach down to the seabed and therefore there preferably have a (not shown) flat foot, which reduces sinking. After completion of the settling process, the traverse 15 from the connection structures 16 it loosens and remains in place (and can then be reused for later lifting) or becomes laterally under the cross 5 pulled out / unfolded and the forest 11 + 12 + 16 , respectively. 11 + 13 + 16 + 15 can be lifted upwards and reused for a next founding.
• - Between the upper and lower end of the cross a variant is shown, in which a lattice mast structure 14 with longitudinal and transverse struts the (in this case entire) foundation cross 5 bordered laterally and above, creating a rigid support structure is formed at the foundation cross over holding structures 12 is releasably attached. After settling the foundation on the seabed becomes the cross 5 from the support structures 12 solved and the forest 14 + 13 + 12 + 11 is removed from the founding cross. This is done either by lifting above the highest point 8th the foundation or the lattice mast structure is, unlike in the figure, laterally open or open and can then with the attached parts 13 . 12 and 11 be deducted laterally.

Also in this case, as shown by the example of the right-hand end of the cross, in principle, supporting the foundation on trusses 15 possible after settling on the seabed from the grid structure 14 or a connection structure 16 be decoupled and remain in place, or under the founding cross 5 be pulled out laterally or folded out.

LIST OF REFERENCE NUMBERS

1

Sea level

2

Seabed

3

Mast of the wind turbine

4

Foundation of the wind energy plant

5

concrete cross

6

Cavity in the concrete cross

7

Claw / foot of the foundation

8th

Transition foundation / mast

9

Mast-shaped part of the foundation

10

Settling mechanism (e.g., fluid filled cylinder) within the foundation

10a

Guide tube or guide channel

10b

Closed top stamp

10c

Top open, tubular stamp

11

Settling mechanism (e.g., fluid filled cylinder) outside the foundation

12

Support structure for fastening the crossbeam 13 at the cross 5

13

Traverse acting as a support of the settling mechanism 11 is

14

Stiffening lattice mast structure

15

Supporting crossbar under the cross 5 (alternatively: cast in cross 5 )

16

Connection structure between traverse 13 and traverse 15

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 1691073 A2 [0033, 0045]

Claims (4)

Method for settling gravitational or shallow foundations 4 from wind energy or marine power plants on the seabed 2 , characterized in that the foundation 4 not in one operation down to the seabed 2 but that the process takes place in at least two steps, wherein - the earlier step, a lowering to an intermediate height above the seabed 2 settling devices supported on the seabed ( 10 . 10a . 10b . 10c . 11 . 12 . 13 . 14 . 15 . 16 ), which are devices other than those which have lowered the foundation to the intermediate height, and - the later step of settling the foundation 4 on the seabed 2 by means of on the seabed 2 supported settling devices ( 10 . 10a . 10b . 10c . 11 . 12 . 13 . 14 . 15 . 16 ), the part of the foundation 4 or solvable at the foundation 4 are fixed, provides. Method according to claim 1, characterized in that the lowering on supports ( 10b . 10c ) of the settling device ( 10 . 10a . 10b . 10c . 11 . 12 . 13 . 14 . 15 . 16 ), which change their length, as long as the foundation is coupled to the moving in the swell ship, and that then the supports are locked in variable length and at the same time or very soon the foundation 4 decoupled from the ship. Method according to at least one of claims 1 and 2, characterized in that the uncoupling of the foundation 4 from the ship with simultaneous or timely locking of the supports ( 10b . 10c ) of the settling device ( 10 . 10a . 10b . 10c . 11 . 12 . 13 . 14 . 15 . 16 ) occurs at a time when the foundation lowered to intermediate height 4 just raised by a wave crest to the maximum height that it reaches through the swell. Depositing device for carrying out the method according to at least one of claims 1 to 3, characterized in that it comprises variable-length, lockable supports ( 10b . 10c ) and guiding devices ( 10a ) for these supports and on each support ( 10b . 10c ) is at least one actuator, with the length of the support is controlled variable.

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