Method for foundation of a transformer platform and transformer platform with at least three piles

Abstract

A method for foundation of a transformer platform having at least four piles (12), in which precisely one pile driver (1) is brought to the location, the pile driver (1) is supported on the seabed (9) by means of extendable supporting legs (7), driving jigs (11) are attached 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) whilst maintaining the position of the pile driver (1), 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 and the pile driver (1) is moved away from the location.

Claims

1. Method for 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 a seabed (9) by means of extendable supporting legs (7), driving jigs (11) are attached 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 and the pile driver (1) together with the retracted supporting legs (7) 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), wherein no jig on the seabed (9) is used.

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.

3. Method according to claim 1, characterised in that the upper platform part (4) is arranged on a framework (3) on the pontoon (2) and the 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 higher than all upper ends of the piles (12) projecting above the surface of the sea 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. Method according to claim 1, characterized in that the piles (12) are driven into the seabed (9) to the height of the driving jig (11) plus 1 m.

5. Method according to claim 1, characterized in that the piles (12) are driven into the seabed (9) to the height of the driving jig (11) plus 0.5 m.

6. Transformer platform, installed by the method of claim 1, containing at least four piles (12) which are driven parallel to one another into the seabed (9), wherein a single structural connection between the piles (12) is an upper platform part (4), characterised in that the upper platform part (4) is placed onto upper ends of the piles (12) and no jig on the seabed (9) is available.

7. Foundation set for a transformer platform containing a pile driver (1) which is supported on a seabed (9) at a location by means of extendable supporting legs (7), and the pile driver (1) has driving jigs (11) through which piles (12) of the transformer platform (6) can be inserted, and the pile driver (1) comprises a hammer (14) for driving all piles (12), and the supporting legs (7) of the pile driver (1) are retractable and the pile driver (1) together with the retracted supporting legs (7) can be moved away from the location, with 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) and no jig on the seabed (9) is available.

8. Foundation set according to claim 7, 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).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is described with reference to an exemplary embodiment in seven drawings. In the drawings:

(2) FIG. 1 shows a first step of a method according to the invention for foundation of a transformer platform by means of a jack-up platform which drives a pile of the transformer platform into the seabed,

(3) FIG. 2 shows a second step in which the pile is already driven some way into the seabed,

(4) FIG. 3 shows a step of the method according to the invention in which the pile is already completely driven into the seabed,

(5) FIG. 4 shows a fourth step in which the second pile of the transformer platform is already completely driven into the seabed,

(6) FIG. 5 shows a fifth step of the method according to the invention in which all the piles of the transformer platform are already driven into the seabed and an upper platform part is brought to the location by means of a pontoon,

(7) FIG. 6 shows a sixth step of the method according to the invention in which the upper platform part is brought by means of the pontoon above the ends of the driven piles and is lowered,

(8) FIG. 7 shows the installed transformer platform with the upper platform part placed onto the piles.

(9) The methods according to the invention are described by way of example with reference to FIGS. 1 to 7.

DETAILED DESCRIPTION OF THE SEVERAL EMBODIMENTS

(10) First of all the method according to the invention is described. It makes use of a foundation set which comprises a pile driver 1, for example in the form of a jack-up platform, as well as a pontoon 2 on which a framework 3 is arranged and on which in turn an upper platform part 4 of a transformer platform 6 to be installed can be arranged. First of all the pile driver 1 is brought to the location. The pile driver 1 itself can be floatable, and for this purpose it has retracted supporting legs 7 and a floatable platform 8.

(11) However, the pile driver 1 can also be brought to the location by means of a barge or the like. The pile driver 1 is arranged in a predetermined manner at the location, i.e. in a predetermined orientation relative to the seabed 9, and then the supporting legs 7 of the pile driver 1 are lowered, so that the pile driver 1 is supported on the seabed 9. The platform 8 can be lifted out of the water by means of jacking systems.

(12) According to FIG. 1, driving jigs 11 are arranged preferably laterally on the pile driver 1. The driving jigs 11 are arranged on the pile driver 1 in such a way that, when piles 12 are inserted vertically, the upper ends of the piles 12 are spaced apart from one another by precisely the spacing of supports on the underside of the upper platform part 4, so that the upper platform part 4 can be placed with its receptacles onto the upper ends of the piles 12 16.

(13) In particular, no jig on the seabed 9 is necessary for foundation of the piles 12.

(14) The pile driver 1 has a crane 13 with a hammer 14 according to FIGS. 1 to 4. This can involve a heavy weight. First of all by means of the crane 13 the first pile 12 is inserted through the first driving jig 11 until it is oriented vertically above the seabed 9, and then is lowered onto the seabed 9. It is placed vertically onto the seabed 9. The jigs 12 can be hinged and/or can also be detachable. Then by means of the hammer 14 the pile 12 is driven into the seabed 9. After a first pile 12 is driven in, the pile driver 1 remains at the predetermined position on the seabed 9, and a second pile 12 is inserted through a second driving jig 11, and by means of the hammer 14 the second pile 12 is driven into the seabed 9. As many piles 12 as are necessary for support of the upper platform part 4 are driven successively into the seabed 9. Four or any higher number of piles 12 can be driven in are being, preferably precisely four piles 12 are driven in. The piles 12 are driven into the seabed 9 to such an extent that the upper end is arranged at least level with the driving jig 11, preferably higher than the driving jig 11. Particularly preferably, the upper end of the pile 12 is level with the upper side of the driving jig 11 after the pile is driven into the seabed 9.

(15) After the piles 12 have been driven in, according to FIG. 5 they are all parallel to one another and vertical. First of all the upper platform part 4 is brought to the location. For this purpose the framework 3 or the like has previously been arranged on the pontoon 2. The framework 3 is a scaffold. The upper platform part 4 is placed horizontally onto the framework 3. The pontoon 2 is also floatable together with the upper platform part 4 and is towed together with the upper platform part 4 to the location. This operation is illustrated in FIG. 5 and FIG. 6.

(16) The pontoon 2 is dimensioned in such a way that according to FIG. 6 it passes through between the piles 12, and the upper platform part 4 is arranged on the framework 3 and on the pontoon 2 so that, as the pontoon 2 passes through, the upper platform part has a position relative to the piles 12 so that by the simple lowering of the upper platform part 4 the receptacles 16 on the underside of the upper platform part 4 are placed directly onto the upper ends of the piles 12.

(17) The lowering of the pontoon 2 can take place by flooding of water tanks. The flooding is represented by two arrows in FIG. 6.

(18) FIG. 7 shows the finally installed transformer platform 6. The transformer platform 6 has relatively thin piles 12 which have no grid structure, so that the entire foundation body only has a very low degree of obstruction for the breaking of waves. Because of the low degree of obstruction the piles 12 can be designed with a small diameter.