EP3530814B1 - Method for the construction of a transformer platform and foundation set for a transformer platform - Google Patents

Description

The invention relates to a method for establishing a substation platform with at least three piles. The invention also relates to the transformer platform, which is preferably installed using such a method and has at least three piles, and a foundation set for carrying out the method.

Due to the expansion of wind energy in the offshore area, substation platforms are becoming necessary. The electricity generated by the individual wind turbines is transformed on the substation platforms and brought to shore from there via a cable. Substation platforms or converter platforms are installed in particular on the German west coast in the North Sea. The area is characterized by extremely high and energetic waves with comparatively shallow water. Known foundation structures such as jackets have a high degree of obstruction and therefore attract high loads by design, making them heavy in design and therefore expensive. It is known to provide pile foundations for substation platforms, in the foundation of which a template is arranged on the seabed and the piles are rammed through the template into the seabed. Several different pile drivers are used for this purpose.

A disadvantage of the known ramming methods is that they do not work with sufficient precision or are relatively expensive.

From the JP 2013-204399 A a method for establishing an offshore platform is known, in which a buoyant platform with raised support legs is brought to the location, some of the support legs are first temporarily extended and the platform is lifted out of the water using a jacking system and then piles using a hammer are rammed into the seabed and the provisionally lowered support legs are additionally rammed further into the seabed.

The object of the present invention is, in a first aspect, to improve an initially mentioned method for founding a substation platform and, in a second aspect, to provide an improved foundation set with which the substation platform can be founded.

This object is solved by the independent claims 1 and 4.

The method according to the invention makes use of the idea of using exactly one piling device that is brought to the location and that is supported on the seabed by means of extendable support legs. The piling device can be a jack-up platform or the like, which preferably has a crane and a hammer.

The term ramming is to be understood here in a very general manner. Ramming is also to be understood, for example, as drilling. A piling device can also be understood here as a drill or a drilling device.

Templates are attached to the pile driver. The templates can be arranged on the outside or inside of a platform of the piling rig, the relative distance between the templates corresponds exactly to the position of the posts of the substation on the seabed, the posts are each rammed vertically into the seabed one after the other.

The piles are each inserted through a ramming template assigned to them on the substation platform. They are favorably suspended vertically.

The piles are driven into the seabed one after the other, preferably while maintaining the position of the piling rig. The support legs of the pile driver are preferably not changed during the entire pile driving process. The piles driven into the seabed remain at the same level as or above the driving template assigned to them. "Up" and "down" refer to orientations away from the seabed and toward the seabed, respectively.

It is also conceivable that a group of piles is driven into the seabed while maintaining the position of the piling rig and the piling rig is then relocated and another group of piles is rammed into the seabed. The platform is then placed on all the posts.

The support legs of the piling rig are then retracted and the piling rig is moved away from the location with the support legs retracted. After driving, the tops of the piles project above the sea surface, preferably all at the same height. The relative distances between the upper ends of the piles correspond exactly to the relative distances of supports of a platform top which is placed on top of the ends of the piles. Advantageously, the piles are rammed into the ground until the upper ends are at most level with the ramming template, preferably +3 m, preferably +2 m, preferably up to +1 m, preferably +0.5 m above the ramming template. The top ends are not rammed through the template. The arrangement of the driving templates corresponds exactly to the relative arrangement of the supports of the platform top as well as the contact points of the piles with the seabed in a horizontal plane.

According to the invention, the platform upper part, which is brought to the location and is placed on the upper pile ends at the location, is arranged on a grillage and on a pontoon. A bottom of the platform top has a height above the sea surface when moving to location, which is higher than all ends of the piles above the sea surface. The pontoon is lowered after the upper part of the platform has been moved over the piles and placed on the ends of the piles. The pontoon is arranged relative to the posts in such a way that when the upper part of the platform is lowered, supports on an underside of the upper part of the platform lie exactly on the ends of the posts.

A transformer platform is preferably installed using one of the methods mentioned above; conversely, one of the methods mentioned above is suitable for installing the transformer platform.

The substation has at least four piles that are rammed into a seabed parallel to one another. The only constructive connection between the piles is the platform top. Of course, the piles are connected in some way above the seabed, but this is not a constructive connection between the piles within the meaning of the invention.

The upper platform part rests on the upper ends of the posts, so in particular the posts are not lowered laterally in guides or held laterally in guides of the upper platform part, but the platform has an underside with receptacles that are preferably closed at the top and rest on the upper ends of the posts .

In the second aspect, the object is achieved by a foundation set for a substation platform with the features of claim 4, which initially consists of a piling device, for example in the form of a lifting platform, and a pontoon with a grillage. The piling device has piling templates which are arranged on it and are fixed to one another. The relative arrangement of the driving templates corresponds exactly to the arrangement of piles of the transformer platform in the assembled state in a horizontal cross-section, i.e. the relative arrangement of the contact points of the piles with the seabed when only considering the horizontal extension. The piling templates are preferably all arranged at the same height above the seabed on the piling device placed thereon.

The piling device advantageously has a hammer with which each of the piles can be rammed into the seabed through the piling template associated with it. The hammer is intended for ramming all piles. The piling rig has support legs which enable the piling rig to be supported in location on the seabed and thus prevent displacement of the piling rig during driving of the at least four, preferably five or any greater number of piles.

Conveniently, the pile driver's support legs are all retractable and extendable. The extended support legs support a platform of the piling rig on the seabed so that the platform can be lifted out of the sea by means of a jacking system or the like. When the support legs are retracted, the pile driver is preferably buoyant so that it can be moved away from the location after the piles have been driven in.

The pontoon is then moved with the upper platform part between the posts and placed in a position such that the supports on an underside of the upper platform part for the posts are arranged exactly vertically above the ends of the posts above the post ends. By lowering the pontoon, for example by flooding water tanks, the platform is lowered and the pads are positioned exactly on top of the piles. Conveniently, the pile driver has as many piling templates as there are piles.

The position of the piling templates can be adjusted for the respective substation platform, i. H. their position can be changed on the pile driver. In their changed position, they are then again fixed in position on the pile driver during the foundation.

Fig. 1

einen ersten Schritt eines erfindungsgemäßen Verfahrens zur Gründung einer Umspannplattform mittels einer Hubinsel, die einen Pfahl der Umspannplattform in den Boden rammt,

Fig. 2

einen zweiten Schritt, bei dem der Pfahl bereits ein Stück weit in den Meeresboden eingerammt ist,

Fig. 3

einen Schritt des erfindungsgemäßen Verfahrens, bei dem der Pfahl bereits vollständig in den Meeresboden eingerammt ist.

Fig. 4

einen vierten Schritt, bei dem der zweite Pfahl der Umspannplattform bereits vollständig in den Boden eingerammt ist,

Fig. 5

einen fünften Schritt des erfindungsgemäßen Verfahrens, bei dem bereits alle Pfähle der Umspannplattform in den Meeresboden eingerammt sind und ein Plattformoberteil mittels eines Pontons auf Lokation verbracht wird,

Fig. 6

einen sechsten Schritt des erfindungsgemäßen Verfahrens, bei dem das Plattformoberteil mittels des Pontons über die Pfahlenden der eingerammten Pfähle verbracht wird und abgesenkt wird,

Fig. 7

die installierte Umspannplattform mit dem auf den Pfählen aufgesetzten Plattformoberteil.

The invention is described using an exemplary embodiment in seven figures. The show

1

a first step of a method according to the invention for establishing a substation by means of a jack-up platform that rams a post of the substation into the ground,

2

a second step, in which the stake is already driven a little way into the seabed,

3

a step of the method according to the invention, in which the pile is already completely driven into the seabed.

4

a fourth step, in which the second post of the substation platform is already fully driven into the ground,

figure 5

a fifth step of the method according to the invention, in which all the piles of the substation have already been rammed into the seabed and a platform upper part is brought to the location by means of a pontoon,

6

a sixth step of the method according to the invention, in which the upper part of the platform is brought over the pile ends of the piles that have been driven in and is lowered by means of the pontoon,

7

the installed transformer platform with the upper part of the platform placed on the piles.

The methods of the invention are in the Figures 1 to 7 described as an example.

First, the method according to the invention is described. It uses a foundation set that includes a piling device 1, for example in the form of a jack-up platform, and a pontoon 2 on which a grillage 3 is arranged, on which in turn a platform upper part 4 of a substation 6 to be installed can be arranged. First, the piling device 1 is spent on location. The piling device 1 itself can be buoyant, for which purpose it has retracted support legs 7 and a buoyant platform 8 .

However, the piling device 1 can also be brought to the location by means of a barge or the like. The piling device 1 is located in a predetermined manner on location, i. H. in a predetermined orientation with respect to the seabed 9, and then the support legs 7 of the piling rig 1 are lowered so that the piling rig 1 rests on the seabed 9. The platform 8 can be lifted out of the water using jacking systems.

At the pile driver 1 are in accordance 1 Ramming templates 11 are preferably arranged on the side. The piling templates 11 are arranged on or on the piling device 1 in such a way that, when piles 12 are pushed through vertically, the upper ends of the piles 12 exactly have the distance from one another which corresponds to a distance between supports on an underside of the upper platform part 4, so that the upper platform part 4 can be placed with its receptacles 16 on the upper ends of the posts 12.

In particular, no template is required on the seabed 9 for the foundation of the piles 12 .

The piling device 1 has a crane 13 with a hammer 14 in accordance with Figures 1 - 4 on. This can be a heavy weight. First, the crane 13 inserts the first pile 12 through the first jig 11 until it is plumb over the seabed 9 and then it is lowered onto the seabed 9 . It is placed vertically on the seabed 9 . The templates 12 can be foldable and/or removable. Then the pile 12 is rammed into the seabed 9 by means of the hammer 14 . After driving in a first pile 12, the piling device 1 remains in the predetermined position on the seabed 9, and a second pile 12 is inserted through a second ramming template 11, and the second pile 12 is rammed into the seafloor 9 by means of the hammer 14. One after the other, as many piles 12 are rammed into the seabed 9 as are required to support the upper part 4 of the platform. Four or any higher number of piles 12 can be driven in, preferably exactly four piles 12 are driven in. The piles 12 are rammed into the seabed 9 to such an extent that the upper end is at least level with the ramming template 11, preferably higher than the ramming template 11. Most preferably, the top of the pile 12 is level with the top of the template 11 after it has been driven into the seabed 9.

The piles 12 are after they are driven according to figure 5 all parallel to each other and perpendicular. Then the platform shell 4 is brought to the location. For this purpose, the grillage 3 or the like is arranged on the pontoon 2 in advance. The Grillage 3 is a scaffolding. The upper part of the platform 4 is placed horizontally on the grillage 3 . The pontoon 2 is also buoyant together with the platform top 4 and is pulled together with the platform top 4 to location. This process is in figure 5 and 6 shown.

The pontoon 2 is dimensioned such that according to 6 fits between the posts 12, and the platform top 4 is arranged on the grillage 3 and on the pontoon 2 such that when passing through the pontoon 2 it is in a position relative to the posts 12 has, so that by simply lowering the upper platform part 4, the receptacles 16 on the underside of the upper platform part 4 touch down directly on the upper ends of the posts 12.

The pontoon 2 can be lowered by flooding water tanks. Flooding is indicated by the two arrows in 6 shown.

7 shows the completely installed transformer platform 6. The transformer platform 6 has relatively thin piles 12 that do not have a lattice structure, so that the entire foundation body has only a very low degree of blockage for the impact of the waves. Due to the low degree of obstruction, the piles 12 can be designed with a small diameter.

Reference List

1

pile driver

2

pontoon

3

barbecue

4

platform top

6

substation

7

support legs

8th

platform

9

Seabed

11

driving templates

12

stake

13

crane

14

hammer

16

Recordings

Claims (5)

1. Method for the foundation of a transformer platform having at least four piles (12), in which precisely one pile driver (1) is brought to a location, the pile driver (1) is supported on the seabed (9) by means of extendable supporting legs (7), driving jigs (11) are attached on or to the pile driver (1), the piles (12) are inserted through the associated driving jigs (11), the piles (12) are successively driven into the seabed (9), upper ends of the piles (12) driven into the seabed (9) are arranged level with or above the associated driving jig (11), the supporting legs (7) of the pile driver (1) are retracted, characterised in that the pile driver (1) is moved away from the location and an upper platform part (4) is arranged on a pontoon (2) and is brought to the location, and at the location is placed onto the upper ends of the piles (12).
2. Method according to claim 1, characterised in that the piles (12) are driven into the seabed (9) until the upper ends of the piles (12) are driven into the seabed (9) to the height of the driving jig (11) plus + 3 m, preferably plus 1 m, preferably plus + 0.5 m, preferably driven into the seabed (9) exactly at the height of the driving jig (11).
3. Method according to claim 1 or 2, characterised in that the upper platform part (4) is arranged on a framework (3) on the pontoon (2) and an underside of the upper platform part (4), when it is brought to the location, has a height above the surface of the sea which is projecting higher above the surface of the sea than all upper ends of the piles (12) and, after the upper platform part (4) is moved over the piles (12), the pontoon (2) is lowered until it is placed onto the upper ends of the piles (12).
4. Foundation set for a transformer platform with a pile driver (1) which can be supported on the seabed (9) at the location by means of extendable supporting legs (7), and the pile driver (1) has driving jigs (11) through which the piles (12) of the transformer platform (6) can be inserted, and the pile driver (1) has a hammer (14) for driving all piles (12), characterised by a pontoon (2) which can be raised and lowered, and is provided with a framework (3) on which an upper platform part (4) is arranged, wherein a height of the framework (3) with the pontoon (2) raised is higher than all the upper ends of the piles (12) driven into the seabed (9).
5. Foundation set according to claim 4, characterised in that on the pile driver (1) precisely the same number of driving jigs (11) are provided as the number of piles (12) necessary for the foundation of the transformer platform (6).

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