DE102013007237A1 - Method of producing a foundation pile for offshore structures and foundation pile for offshore structures and offshore construction with pile foundation - Google Patents

Abstract

The invention relates to a method for producing a foundation pile for offshore structures, the method comprising the following method steps: providing and arranging a drop anchor at a predetermined height above the seabed, attaching at least one flexible tension element to the drop anchor, attaching at least one casting compound line on the tension element, - throwing off the drop anchor so that it penetrates the sea bed, and - introducing a hardenable potting compound into the firing channel generated by the drop anchor when it penetrates the sea bed.

Description

The invention relates to a method for producing a foundation pile for offshore structures. The invention further relates to a foundation pile for offshore structures and an offshore structure with a pile foundation.

Offshore structures in the context of the present invention are, for example, wind turbines, substations or drilling or production platforms.

For certain foundation types for offshore structures, in particular for offshore wind turbines, a pile foundation in the seabed is required. Common foundation types are for example so-called monopiles, jackets, tripods or tripiles. To anchor these foundations in the seabed, one or more steel piles are first driven into the seabed. For example, a steel grid structure / steel tube structure is placed on the steel piles in the case of a jacket foundation, which receives a so-called "transition piece" above the sea level. The transition piece then takes on the actual structure, for example in the form of a steel tower. The tower receives at its uppermost end the wind power generator with a rotor.

The ramming of foundation piles, also referred to as "piles", is associated with noise emissions, which are undesirable in particular because they cause damage and behavioral disturbances of marine mammals. It is therefore known and sometimes required to carry out deterrent measures and / or noise abatement measures before carrying out pile driving to ensure that no marine mammals are in the vicinity of the pile work and / or that the sound is reduced to the permitted limit.

Since the depth of penetration of the rammed steel piles and the progress of such pile work on the strength of the seabed is dependent, the setting of steel piles has the disadvantage that the piles of a foundation placed on multiple piles are not always anchored with the same depth of penetration in the seabed.

Depending on the nature of the seabed, the piles must be driven with considerable depth into the seabed, as the stability of the piles is only ensured if the piles have been driven into the ground to a sustainable soil horizon. Under certain circumstances, the actual load of the piles may be higher than the assumed load bearing requirements, which may ultimately result in the failure of a foundation pile. Under certain circumstances, the load and material fatigue caused by the piling process can exceed the predicted and calculated amount, so that the pile must either be completely abandoned or has a reduced life expectancy. The danger of a local structural failure, for example due to dents, increases with greater depth of foundation.

Connecting the underwater constructions of the foundation to the foundation piles requires potting the compound with water curable potting compounds or other expensive bonding techniques.

The piles have to be set at a specified distance, which is ensured by means of the template in the so-called "prepiling". This presupposes that the ground condition is such that all piles to be set can be driven to the given soil horizon. There are no variations with regard to the distance or the place for setting the piles.

When placing larger piles, undersea currents can lead to the seabed bottoming out in the area of the piles. In that case, further measures must be taken to prevent the bottom of the sea from being cleared.

The invention is therefore based on the object to provide a particularly simple method for producing a foundation pile for offshore structures, which in particular is not subject to the aforementioned limitations.

• – Bereitstellen und Anordnen eines Fallankers in einer vorbestimmten Höhe oberhalb des Meeresbodens,
• – Befestigen wenigstens eines flexiblen Zugelements an dem Fallanker,
• – Befestigen wenigstens einer Vergussmasseleitung an dem Zugelement,
• – Abwerfen des Fallankers, so dass dieser in den Meeresuntergrund eindringt und
• – Einbringen einer aushärtbaren Vergussmasse in den von dem Fallanker bei dem Eindringen in den Meeresuntergrund erzeugten Schusskanal.

The object is achieved by a method for producing a foundation pile for offshore structures, comprising the following method steps:

• Providing and arranging a drop anchor at a predetermined height above the seabed,
• Attaching at least one flexible tension element to the fall anchor,
• Attaching at least one potting grounding line to the tension element,
• - Throwing off the drop anchor so that it penetrates into the seabed and
• - Introducing a curable potting compound in the shot channel generated by the fall anchor in the penetration into the seabed.

As a shot channel in the context of the present invention, the displacement channel generated by the fall anchor when immersed in the sediment of the seabed is called.

The invention is based on the idea of using at least one anchor point in the seabed by means of a drop anchor and at least one anchored to the anchor anchor anchor at the anchorage on which the anchorage trunk is posted.

The fall anchor is dimensioned, for example, in terms of its mass and in terms of its geometry so that it penetrates due to its kinetic energy in free fall to a predetermined depth in the seabed. This takes in the case of this battered anchor trunk. One or more potting ground lines can be fastened to the anchor line, which are also carried along by the drop anchor. By means of this potting mass line, a curable potting compound, for example a concrete curable under water, is then pressed under pressure into the firing channel, wherein the anchor branch simultaneously serves to reinforce the potting mass column thus produced in situ.

As a fall anchor according to the present invention, for example, a so-called torpedo pile is provided, which has a torpedo-shaped base body with a Eindringpitze and the end is provided with a plurality of torpedo wings for the purpose of stabilization.

The torpedo body may for example be hollow and comprise one or more ballast chambers that can be filled with a ballast.

The method has in particular the advantage over conventional pile foundations that a bracing of the structure to be paid to one or more anchor lugs can be done, which naturally leaves a certain amount of space in the placement of the offshore structure, so that the setting of the foundation piles not by a template or the underwater structure of the structure is given.

In addition, the setting of piles by means of piling devices is eliminated. The process of setting the torpedo / fall arrester is unique, whereas the ramming of stakes is accompanied by a recurring regularly frequent sound entry into the marine environment.

As a tension element in the context of the present invention, an anchor line or an anchor chain or an anchor cable is provided.

Of course, a plurality of tension elements / anchor cables, or anchor cables, or anchor chains can be attached to a fall anchor, although the following is a tension element in each case.

In any case, a tension element in the sense of the invention is a flexible tension element which can transmit only tensile forces, but not compressive forces.

In an advantageous variant of the method according to the invention it is provided that the potting compound is introduced over at least a partial length of the tension element in the firing channel, wherein the tension element remains in the cured potting compound. The tension element serves on the one hand the reinforcement of the potting compound, on the other hand, the bracing of the offshore structure to be built. Thus, the depth to be reached by the fall anchor depth is reduced because the required for bracing humor of the main structure of the tension element jacket friction is reduced and is supplied by the Vergussmassenkörper.

Conveniently, the tension member is provided at the side remote from the anchor anchor side with at least one float, which is arranged at a predetermined distance from the fall anchor, the distance chosen according to the planned depth of penetration of the drop anchor into the seabed and the height of the sea level above the seabed is such that the tension member and the potting grounding line connected thereto can float so that they can be captured by a supply ship.

The fall anchor is expediently provided with ballast before being dropped off, wherein the ballast mass is chosen such that the fall anchor penetrates into the seabed up to a load-bearing soil horizon.

In a particularly advantageous variant of the method, it is provided that the drop anchor is suspended from a discharge line and the dropping takes place by actuating a triggering mechanism on the discharge line. The fall anchor is struck in this case both on the discharge line as well as on one or more tension members.

In a favorable variant of the method according to the invention it can be provided that the fall anchor is introduced through a protective tube or a sheet pile wall into the seabed, wherein the protective tube or the sheet pile enclosure were previously set.

In order to facilitate penetration of the fall anchor into the seabed, provision may be made for the seabed to be fluidized beneath the protective tube or within the sheet pile enclosure prior to the fall anchor being removed by injection of compressed air or water.

Alternatively, it can be provided, for example when using a protective tube, that the Protective tube is pumped empty before dropping the fall anchor, so that the kinetic energy with which the drop anchor can penetrate into the seabed, significantly increased.

Alternatively, the protective tube, which may extend, for example, beyond the sea level, be pumped with a liquid, so that at the pipe base through the liquid column, an increased hydrostatic pressure is built up, which facilitates the penetration of the drop anchor into the seabed. The liquid column can be adjusted accordingly, for example, with regard to its specific weight. For example, can be used as a liquid barium spar solution application.

The protective tube can, for example, be flushed into the seabed to a certain depth before the drop anchor is dropped off.

The potting ground line can be provided, for example, with a plurality of outlet openings or outlet nozzles provided at a distance from one another in the longitudinal direction, so that the potting compound can penetrate uniformly over the height of the tension element into the firing channel.

It is also possible that the potting grounding line is pulled during potting. Then it is not absolutely necessary to provide several outlet openings for the potting compound. However, a pulling of the potting ground line can also be provided if a potting ground line with a plurality of distributed over the height and / or circumference arranged outlet openings for the potting compound application.

The potting ground line can be lost at least over a subsection extending in the firing channel, i. H. remain in the firing channel via this section.

The object underlying the invention is further achieved by a foundation pile for offshore structures, comprising a drop anchor, at least one cast on this anchor line as a tension element and a cast in situ within the seabed and extending within the seabed over a length Vergussmassesäule, wherein the anchor tube extends over a partial length within the Vergussmassäule and at least to the sea level. The foundation pile according to the invention may comprise at least one protective casing which extends only over a partial length of the casting-mass column.

Alternatively, the foundation pile may be provided with a sheet piling enclosure extending over a partial length of the potting column.

The object underlying the invention is finally achieved by an offshore structure with a pile foundation, comprising a plurality of sinker sunk in the seabed and above the drop anchor extending, in-situ grouted Vergussmassesäulen, wherein the building is covered by anchor lugs, which are posted on the drop anchors.

Appropriately, the anchor lugs each extend through a Vergussmassäule or in this approximately longitudinally.

The offshore structure according to the invention may for example comprise a monopile, which has been constructed in a conventional manner and which comprises a bracing over a plurality of anchoring lugs.

The offshore structure according to the invention comprises a pile foundation formed according to the invention, the pile foundation being carried out by the method according to the invention.

The invention will be explained below with reference to an embodiment shown in the drawings.

Show it:

1 1 shows a side view of a monopile foundation of an offshore structure according to the prior art,

2 1 shows a corresponding view of an offshore structure, which is founded according to the invention,

3 : shows a top view of the view according to 2 .

4 FIG. 1 shows a representation of a torpedo pile according to the invention, FIG.

4a to 4c : show the torpedo line according to 4 each in the upper view with one, four or five anchor tubes and

5 . 5a . 5b : the settling of the torpedo pile according to the method of the invention.

It is first referred to 1 that a monopile 1 according to the prior art shows. On the monopile 1 is a transitional piece 2 with a platform 3 and a not shown Connection structure attached. The transition piece 2 is referred to in the art as a so-called "transition piece".

The monopile 1 according to the invention has a relatively large diameter and was either by ramming or flushing into the seabed 4 set.

The 2 shows in direct comparison to the 1 an offshore structure according to the invention also comprising a monopile 1 , a transition piece 2 and a platform 3 ,

The monopile 1 However, according to the invention is shorter and slimmer than the monopile 1 according to the prior art. The former is over four anchor cables 5 guyed, each one to a foundation pile 6 in the seabed 4 is struck. More precisely, every anchorage is great 5 at a torpedo pile 7 attached and extends through one above the torpedo section 7 arranged Vergussmassesäule 8th , which was shed in situ in the seabed. The potting column 8th has been created without permanent formwork and without standpipe, as will be explained below. Accordingly, the Vergussmassäule 8th no regular outer contour.

The 3 shows a plan view of the arrangement according to 2 ,

An embodiment of the torpedo pile 7 is in 4 shown. The torpedo pile 7 is a drop anchor in the sense of the above. This includes a torpedo-shaped body 9 , which at its leading end is a penetration tip 10 and its trailing end with four wings 11 is provided.

At the trailing in the direction of fall / rear end of the body 9 is an anchor trunk 5 struck, concentric to a casting ground line 12 is arranged.

In the example shown is an extra concentric arrangement of Vergussmasseleitung and the anchor pipe 5 provided, such that the anchor cable 5 within the casting ground line 12 extends, alternatively, of course, may be provided, one or more Vergussmasseleitungen 12 parallel to the anchor line in question 5 relocate.

Of course, with a torpedo pilot 7 several anchor lugs 5 be connected as it is in the 4b and 4c is hinted at. These figures show each, as well as 4a , a top view of the torpedo pile 7 according to 4 ,

In the method according to the invention, the torpedo parts are provided 7 taking advantage of a certain height of fall and falling energy into the seabed 4 to shoot, with the torpedo pile 7 while the anchor trunk 5 as well as the casting ground line 12 entraining. Then in the through the torpedo parts 7 generated shot channel in the seabed 4 a potting compound, such as concrete, pressed under pressure, so that the in 2 above the torpedo pile 7 extending Vergussmassesäule 8th results. As potting compound is a concrete or anchor mortar into consideration. Hardens the potting compound, this results in the 2 illustrated foundation pile 6 from which the anchor trunk 5 led out. The settling of the torpedo pile 7 is in the 5 . 5a and 5b shown relatively simplified.

The torpedo pile 7 hangs on a crane 13 who was on a makeshift platform already built 3 is set up. The platform 3 can be part of the offshore structure to be anchored.

The torpedo pile 7 is on the one hand at the anchorage 5 struck, on the other hand on a discharge line 14 suspended.

At this point it should be noted that of course the torpedo parts 7 can be fired from a ship.

With 15 is called a protective tube whose diameter is slightly larger than that of the torpedo pile 7 is. The protective tube was only slightly into the seabed 4 washed in and extends well above sea level 16 ,

The torpedo pile 7 gets into the top of the protective tube 15 introduced, then then the torpedo parts 7 from the discharge line 14 separated or with the discharge line 14 discarded using its kinetic energy. The torpedo pile 7 falls through the protective tube 15 and penetrates into the seabed 4 a, in the simplest case, only those at this battered anchor trunk 5 and the casting ground line 12 entraining.

At the far end of the anchorage 5 is a float 17 attached, which is a floating of the anchorage 5 allows. The anchor trunk 5 can be picked up in this way by a supply ship and attached to the offshore structure and stretched, for example.

The torpedo pile 7 may have been provided with appropriate ballast prior to discharge, which is why the body 9 of the torpedo pile 7 can be provided with appropriate chambers.

The mass of a torpedo pile can amount to approximately between ten and one hundred tons, such a torpedo pile can for example have a length of up to twenty meters and a diameter of up to one meter.

LIST OF REFERENCE NUMBERS

1

monopile

2

Transition piece

3

platform

4

Subsoil

5

anchor lines

6

foundation pile

7

Torpedopile

8th

Vergussmassesäule

9

base body

10

indenting

11

vanes

12

Vergussmasseleitung

13

crane

14

shedding strand

15

thermowell

16

Sea level

17

float

Claims (18)

Method for producing a foundation pile for offshore structures, comprising the following method steps: Providing and arranging a drop anchor at a predetermined height above the seabed, Attaching at least one flexible tension element to the fall anchor, Attaching at least one potting grounding line to the tension element, - Throwing down the drop anchor so that it penetrates into the seabed, and - Introducing a curable potting compound in the shot channel generated by the fall anchor in the penetration into the seabed. A method according to claim 1, characterized in that the potting compound is introduced at least over a partial length of the tension element in the firing channel, wherein the tension element remains in the cured potting compound. Method according to one of claims 1 or 2, characterized in that the tension element is provided with at least one floating body, which is arranged at a predetermined distance from the fall anchor, the distance to the planned depth of penetration of the drop anchor in the seabed and the height of the Sea level above the seabed is chosen. Method according to one of claims 1 to 3, characterized in that the drop anchor is provided with ballast prior to discarding, wherein the ballast mass is chosen so that the drop anchor penetrates to a viable soil horizon in the seabed. Method according to one of claims 1 to 4, characterized in that the drop anchor is suspended from a discharge strand and the dropping takes place by actuating a triggering mechanism on the discharge line. Method according to one of claims 1 to 5, characterized in that the drop anchor is brought through a protective tube or through a sheet pile enclosure in the seabed. A method according to claim 6, characterized in that the protective tube is flushed before dropping the drop anchor into the seabed. Method according to one of claims 6 or 7, characterized in that the seabed is fluidized within the protective tube or within the sheet pile enclosure prior to the dropping of the drop anchor by injection of compressed air or water. A method according to claim 6, characterized in that the protective tube is pumped empty before the drop anchor. Method according to one of claims 1 to 9, characterized in that at least one Vergussmasseleitung with a plurality of longitudinally spaced-apart outlet openings for the potting compound is applied. Method according to one of claims 1 to 10, characterized in that the Vergussmasseleitung is pulled during the casting. Method according to one of claims 1 to 11, characterized in that the Vergussmasseleitung is lost at least over the extending in the firing channel portion. Foundation pile ( 6 ) for offshore structures using a fall anchor ( 7 ), at least one anchored to this anchor ( 5 ) and one in situ within the subsoil ( 4 ) and within the subsoil ( 4 ) over a length extending Vergussmassesäule ( 8th ), wherein the anchor line ( 5 ) within the potting column ( 8th ) and at least to the sea level ( 16 ). A foundation pile according to claim 13, having protective piping extending over a partial length of the potting column ( 8th ). A foundation pile according to claim 13 having a sheet pile wall which extends over a partial length of the grout column ( 8th ). Offshore structure with a pile foundation comprising several in the seabed ( 4 ) submerged torpedo piles ( 7 ) and above the torpedo piles ( 7 ) extending in situ potted grouting columns ( 8th ), whereby the structure is supported by anchor lugs ( 5 ) is taut, which at the Torpedopiles ( 7 ) are struck Offshore structure according to claim 16, characterized in that the anchor lugs ( 5 ) extend through the Vergussmasstäulen. Offshore construction according to one of claims 16 or 17, characterized in that it comprises a monopile ( 1 ) and a guy over several anchor lugs ( 5 ).

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