EP2877638B1 - Foundation for a wind motor - Google Patents

Description

The present invention relates to a dissolved structural structure, in particular a lattice tower structure, for a wind energy plant according to the preamble of claim 1. In particular, the invention relates to a foundation structure which is designed as a dissolved structural structure, in particular as a lattice tower structure, and e.g. is anchored as an offshore foundation structure by means of rammed foundation piles, in particular by means of pre-drilled hollow piles, to the ground. Furthermore, the present invention relates to a method for producing a dissolved structural structure, in particular a lattice tower structure, according to the preamble of claim 13.

As resolved structural structures, for example, tripods, tripiles or lattice tower structures are called. In the following, the invention is explained using the example of such lattice tower structures, without this being to be understood as a restriction. Straight lattice tower structures are well known in wind turbines, eg as lattice towers for wind turbines as an alternative to tubular steel towers. There are also lattice tower structures known as foundation structures over which the connection of a building with the ground. Such known foundation structures consist for example of a lattice structure of corner posts and trusses arranged between the corner posts struts. In other dissolved structural structures one does not speak of corner stems, but of legs. Anchoring on the ground, eg on the seabed, takes place, for example, via rammed foundation piles, which are designed, for example, as hollow piles, in order to be able to receive the lower ends of the corner stems. Then mortar (Grout) is filled into the hollow piles to firmly connect the corner posts with the piles. As a rule, for the connection with the foundation piles, the corner stalk is extended at its free end with so-called jacket legs. These jacket legs are mounted so that they stand in the vertical direction in the foundation piles, while the corner stems have a tilt to the vertical direction. These jacket legs are according to the diction of the present application part of the corner stem and thus covered by the term "corner stem". The joining of the corner stems with the piles can therefore also be the joining of the jacket legs with the piles.

This example from the DE 20 2011 101599 U1 Known foundation structures are commonly referred to as jacket foundations and used predominantly in the offshore area, that is, the foundation structure is in the sea and the hollow piles are anchored in the seabed. On the foundation structure, a tower construction, in particular a wind turbine can be arranged, for example, a wind turbine with a lattice or a steel tube tower.

The aforementioned lattice tower structures consist of so-called primary and secondary structures. The primary structures are those parts of the lattice tower structure that remove the loads from the wind turbine. These loads include static, eg resulting from the weight of the wind turbine, and also dynamic loads, for example, resulting from the rotor rotation and changing winds. The primary structures include, for example, the corner stems and the struts connecting the corner stems and extending between the corner stems. These include nodes, eg cast and weld nodes. In contrast to this, the secondary structures do not have a load-bearing function which is relevant to stability, but are intended to fulfill functional tasks and the associated tasks Loads (eg impact loads from service vessels to jetty) into the primary structure. Secondary structures are, for example, cable guide tubes (J-tubes), platforms and feeders for landing boats, work platforms, or pile stoppers on the anchoring-side end portions of the corner stems which control the depth of penetration of a corner stalk when inserted into a seabed limit the drilled hollow pile. This list is only an example and not exhaustive. Unlike the primary structures, the failure of a secondary structure does not affect the stability of the overall structure.

In known lattice tower structures, the secondary structures via material connection, in which the material of the structures is metallurgically changed, as z. B. when welding is the case, connected to the primary structures. For example, Platforms are welded to the corner posts or braces. The disadvantage of welded joints is that the metallurgical change of the structure produces a notch effect which reduces the fatigue strength of the structure. As a result, in particular, the primary structure must be made larger in order to compensate for the reduction in fatigue strength, thereby increasing the cost of the lattice tower structure.

The object of the present invention is to provide an improved lattice tower structure or dissolved structural structure in this respect.

The object is achieved with a lattice tower structure or with a dissolved structure structure with the features of claim 1. Advantageous embodiments are specified in the dependent claims.

The lattice tower structure according to the invention or dissolved structural structure is characterized in that the cohesive connection between the primary and the secondary structure is designed as a bonding connecting layer arranged between primary and secondary structure.

In the present invention, welding is no longer required to make the connection between the primary and secondary structures, but the connection is made via a bonding layer. The bonding layer has the advantage that no metallurgical changes in the material structure are generated and thus no notch effect occurs. Accordingly, the fatigue strength of the load-bearing primary structures in particular is not impaired. This has the consequence advantageously that the primary structures and also the secondary structures over the prior art at least partially lighter dimensions and costs can be saved accordingly.

According to an advantageous embodiment, the connection layer may be an adhesive layer. Adhesive connections are basically already known in steel construction. Suitable adhesive bonds and adhesives are described inter alia in the article " Gluing in steel construction "in the journal Stahlbau 75 (2006), Issue 10, pages 834 ff., Authors: Markus Feldmann et al. described.

An alternative bonding agent to adhesive may be (normal or high strength) grout according to another aspect of the invention. Also mortar compounds (also called Grout compounds) are basically known from the prior art, so that no further explanation is required.

In principle, the primary and secondary structures could be directly bonded to one another with a material fit, the adhesive or coarse layer would then be arranged directly between the two attachment partners. An advantageous embodiment of the invention provides, however, that the secondary structure is attached to a sleeve, in particular by welding, and that the sleeve rests positively on the primary structure, wherein the connection layer is formed between the sleeve and the primary structure.

In other words, one could also view the cuff as part of the secondary structure, which makes no technical difference. In this application the view was taken that the cuff is not part of the secondary structure, even if the cuff and secondary structure are integrally formed. Recognizable is only a selected definition.

This embodiment according to the invention offers the advantage that the secondary structure does not have to be fastened directly to the primary structure, which is e.g. then a problem can be if only small interfaces are available. The cuff may have a bonding surface of suitable size and contour, and the secondary structure may be e.g. welded to the cuff. But cuff and secondary structure can also be connected in other ways or be made in one piece. A cuff has the advantage that it can be produced in a variety of sizes and shapes, and that the loads occurring through the secondary structure are removed via the cuff and via the bonding layer to the primary structure, without structurally weakening the primary structure.

In this case, the sleeve can be formed according to a further embodiment, at least two parts. This embodiment offers the advantage that the collar can be arranged in a simple manner on the primary structure. For tubular primary structures, the sleeve may e.g. consist of two 180 ° shells that complement each other, possibly together with auxiliary shells, to form a closed ring. The dishes may e.g. be joined by welding or screwing.

It would also be conceivable according to an embodiment of the invention for not very heavily loaded compounds to form the cuff as a partial shell. This embodiment has the advantage that the sleeve would only partially cover the primary structure and can thus be mounted easily and quickly.

Advantageously, the invention can be implemented if the dissolved structural structure or the lattice tower structure is a foundation structure, the primary structure a corner stem or a leg, and the secondary structure a support for the depth limitation of the corner stem or leg when inserted into pre-excavated hollow piles is. These supports are also referred to as pile stoppers. It proves to be a particular advantage that the fastening according to the invention by means of a connecting layer with respect to the welding can be implemented more advantageously and without problems in terms of construction. For in the prior art, the pile stopper is welded to the Eckstiel well before the establishment of the foundation structure, namely on land in a workshop. The reason for this is that the production of a welded connection takes time and then the welded joint has to be tested with regard to its strength and possibly certified. This leads to the disadvantage that the arrangement of the pile stoppers on the corner stems or legs is not very accurate to the encountered actually in the establishment of the foundation pile heights, which only after the measurement of the piles z. B. after ramming is determined. This is a known problem, and in the prior art this problem is addressed by placing lining plates between the pile top edges and the pile stoppers as height compensation. The WO2011 / 010937 A1 deals among other things with this problem of height compensation.

In contrast, the embodiment of the invention has the advantage that the connection between the corner post and the pile stopper after the measurement of the pre-piles can be made either directly on site or just before loading on land, so that the arrangement of the pile stopper at the corner handle can be adapted to the actual pile height on site. This is possible because both an adhesive and a mortar compound in a relatively short time and in consistently good quality can be produced.

A requirement for offshore wind turbines is that they must have sufficient earthing. This resulted in the prior art that when using height compensation plates, especially those with elastic properties, no electrical contact between corner post and foundation pile was that would otherwise have been produced by the resting on the pile pile stopper, so that subsequently a electrical connection had to be made, for example, by subsequent attachment of a conductor between pile stopper and foundation pile. This work had to be done by divers. The subsequent arrangement of such an electrical conductor is no longer necessary in the embodiment according to the invention, since the pile stopper advantageously rests directly on the pile, whereby an electrical line is produced. Due to the connecting layer between pile stopper and corner handle, which is usually non-conductive, if necessary, an electrical connection between corner handle and pile stopper must be made, but this is easily executable during the attachment of the pile stopper, and thus without the arduous and risky use of divers is feasible.

After the corner posts in the foundation piles are vergroutet, according to the state of the art, no load transfer more about the pile stopper, but only about the mortar compound of the corner posts in the foundation piles. Nevertheless, it may happen that loads are at least partially transmitted via the pile stoppers. This is problematic because of the notch effect of welds. To avoid such problems, the pile stoppers are therefore often removed in dives once the mortar has set in the foundation piles.

In contrast, the embodiment according to the invention has the advantage that no notch effect occurs due to the connection type according to the invention. Accordingly, the pile stopper would not have to be removed, because a partial load transfer is unproblematic here. If there would be a failure of the compound according to the invention after the establishment of the foundation, this would even be the case, since then there is a load transfer to 100% via the Grout connection.

According to an advantageous embodiment of the invention, the pile stopper of a bottom-side Auflagerringplatte with central through hole for the corner handle or the leg, arranged from a ring inside the Auflagerringplatte, surrounding the through hole, cylindrical extension piece and constructed of a plurality of reinforcing fins, which are arranged along the circumference of standing substantially perpendicular to the Auflagerringplattenebene extension radially outwards, in particular delta form, between Auflagerringplatte and extension piece, the Auflagerringplatte the pole sized in a foundation pile inserted Eckstiel or leg radially outstanding is. This structure is characterized as material-saving and yet stable. It is advantageous according to a further embodiment of the invention that the pile stopper is formed at least two parts, since a split pile stopper is easier to mount on a corner post or leg and easier to handle.

A further advantageous embodiment of the invention provides that in the opening of the pile stopper spacers are arranged, via which the corner post or the leg is held in the opening at a distance from the pile stopper. This ensures that a sufficient annular gap for the introduction of the bonding layer is present.

A further advantageous embodiment of the invention provides that in particular the region of the connecting layer is provided with a corrosion protection, for example with a corrosion protection coating or a coating.

A secondary structure according to the invention can also be a cable guide tube or a jetty according to another embodiment of the invention.

As mentioned above, the foundation structure according to the invention is not limited to lattice structures consisting of corner posts and trusses arranged between the corner posts struts, but also includes structures in which no distinction can be made between corner post and strut (eg "Hexabase-Jacket" or DE 20 2011 101 599 U1 , or other dissolved structural structures, eg tripods). Here one no longer speaks of cornerstones, but of legs. The term "leg" is also used in the claims.

The object is further achieved by a method having the features of claim 13. Advantageous method embodiments are specified in the subclaims.

Fig. 1

eine schematische Darstellung einer erfindungsgemäßen Gründungsstruktur,

Fig. 2

eine Detailansicht des in Fig. 1 mit X gekennzeichneten Bereiches eines Ausführungsbeispiels für einen geklebten Pile-Stopper im Schnitt,

Fig. 3

eine isometrische Ansicht des in Fig. 2 dargestellten Pile-Stoppers,

Fig. 4

eine Detailansicht des in Fig. 1 mit Y gekennzeichneten Bereiches eines weiteren Ausführungsbeispiels für einen gegrouteten Pile-Stopper,

Fig. 5

eine isometrische Ansicht des in Fig. 4 dargestellten Pile-Stoppers, und

Fig. 6

eine Detailansicht des in Fig. 1 mit Z gekennzeichneten Bereiches eines Ausführungsbeispiels für eine erfindungsgemäße Verbindung einer Sekundärstruktur mit einer Primärstruktur im Schnitt.

In the following the invention will be explained in more detail with reference to several exemplary embodiments shown in the figures. Show it:

Fig. 1

a schematic representation of a foundation structure according to the invention,

Fig. 2

a detailed view of the in Fig. 1 X marked area of an embodiment for a glued pile stopper in section,

Fig. 3

an isometric view of the in Fig. 2 illustrated pile stopper,

Fig. 4

a detailed view of the in Fig. 1 marked with Y range of another embodiment of a grooved pile stopper,

Fig. 5

an isometric view of the in Fig. 4 shown pile stopper, and

Fig. 6

a detailed view of the in Fig. 1 Z marked area of an embodiment of an inventive compound of a secondary structure with a primary structure in section.

In the Fig.1 a foundation structure 1 for a tower construction 2 is shown. In this foundation structure 1 is a jacket for an offshore structure, such. B. for an offshore wind turbine, that is, that the jacket is anchored to the seabed 6, wherein the foundation structure 1 is formed and arranged so that its upper part is above the sea level 7.

The jacket consists of corner posts 3 and arranged between the corner posts 3 and attached thereto struts 4. These components are load-bearing parts, which are referred to as primary structures. The Corner handles 3 are anchored on hollow foundation piles 5 in the seabed 6, wherein the immersion depth of the corner handles 3 in the foundation piles 5 by pile stoppers 8, 9 is limited. As will be shown in detail later, are in FIG. 1 two different pile stoppers shown, namely at the left corner stem a pile-stopper 8 fastened by gluing, at the right corner stalk a pile stopper 9 connected by grout.

The Fig. 2 shows the in Fig. 1 X area in enlarged and cut view. Shown is a corner handle 3, which is verground in a pre-grounded in the seabed foundation pile 5 via a mortar connection 26 with the pile 5. On the corner post 3, shear ribs 27 are provided on the outside in the area penetrating into the pile 5. Furthermore, an insertion aid 22 is formed at the lower end of the corner handle 3.

On the upper end of the foundation pile 5, a pile stopper 8 is supported. The pile stopper 8 has a pile-side bearing surface 24 a, via which the support plate 24 rests on the pile 5. It also has reinforcing fins 24b, 24c which extend downwardly (24b) and upwards (24c) from the support plate 24, respectively. The support plate 24 is connected via an adhesive connection with the corner handle 3. For better representability, only the left part of the support plate 24, the adhesive bond producing adhesive layer 28 is shown.

Fig. 3 shows in an isometric view the in Fig. 1 X marked detail based on FIG. 2 has already been described in detail. The attached by means of an adhesive bond on the corner post 3 Pile-stopper 8 consists of a circular ring plate 24, as the like Fig. 2 has a central passage opening for the corner handle 3. This passage opening is dimensioned such that the corner post 3 with the pile stopper 8 forms an annular gap therebetween, into which an adhesive for forming an adhesive layer 28 is introduced. So that this annular gap formed as evenly as possible is, are provided on the annular gap-side surface of the pile stopper, ie on the corner handle 3 facing surface, spacers in the form of circumferential annular beads. After introduction of the adhesive composition in the annular gap and after curing or setting of the adhesive composition of the corner handle 3 and the pile stopper are connected. In this case, the adhesive can be chosen so that the compound still has a certain elasticity, so that the pile stopper 8 can still move elastically to a certain extent in the longitudinal direction of the Eckstieles 3.

The annular plate 24 of the Eckstieles 3 rests on its underside 24a on the foundation piles 5. On the upper side of the ring plate 24, a cylindrical sleeve 29 is fixed stabilized substantially perpendicular to the annular plate 24 by means of stiffening fins 24c. In the exemplary embodiment shown, the pile stopper 8 is constructed from four 90 ° ring segments 8a to 8d. These ring segments 8a to 8d are screwed together at the pairwise abutting interfaces. For this purpose, holes 30 for the passage of bolts are provided in the adjacent reinforcing fins 24c.

In the annular plate 24 four holes 31 are provided which allow the escape of sea water when filling grout 26 in the foundation piles 5 and also allow observation of the pile interior, z. B. by remote-controlled cameras to monitor the successive filling of the pile 5 with Grout 26. For the production of a conductive contact between corner handle 3 and pile stopper 8 at least one electrical grounding cable 32 is provided. Since the ring plate 24 rests directly on the pile 5, a conductive connection between these two components is ensured. In addition, however, further grounding can be made by providing a corresponding grounding cable.

The FIGS. 4 and 5 show an alternative type of pile stopper 9. In the sectional view of Fig. 4 It can be seen that the annular gap 33 formed between corner post 3 and pile stopper is significantly larger than in the adhesive variant. This annular gap 33 is filled to attach the pile stopper 9 at the corner handle 3 with a grout 34, and after setting the Groutmasse 34 there is a firm connection between corner handle 3 and Pile-stopper 9. This compound can be further improved in strength, that thrust ribs 35 are formed on the corner stalk-side inner surface of the pile stopper 9. Functionally identical push ribs 27 also has the corner handle 3 on its anchoring-side end region. These push ribs 35 and 27 allow a more stable connection both with the grout 34 filled in the annular gap 33 and with the groove 26 filled in the pile 5.

Incidentally, there is also connected by Grouten Pile-stopper 9 of a base plate 40 and a cylinder 41 arranged perpendicular thereto, which surrounds the central opening in the base plate 40 and forms the annular gap 33 together with the corner handle 3. Between Eckstiel 3 and Pile-stopper a ground wire 32 is again mounted to make an electrically conductive connection. Also, the pile stopper 9 of Fig. 5 consists of four 90 ° segments 40a-40d bolted together to form a 360 ° pile stopper. There are also other segmentations conceivable, for. B. a subdivision into two, three, or more than four segments. The division into segments is advantageous because it makes handling easier.

The attachment of the pile stopper 8 or 9 to the corner post 3, unlike in the prior art, only immediately before the attachment of the lattice tower structure 1 to the foundation piles 5 done. The height up to which the foundation piles 5 protrude out of the seabed 6 can be measured and thereby the desired height position of the pile stoppers 8, 9 at the corner post 3 can be determined. In this desired position can then be the pile stoppers 8, 9 secure by gluing (8) or by Vergroutung (9) at the corner post 3 and after setting of the connection can then the lattice tower structure 1 is lowered onto the foundation piles 5 and the lower end 22 of the corner posts 3 (Groutzapfen) are introduced into the foundation piles 5 until the Pile stoppers 8, 9 come to rest on the upper edges of the foundation piles 5. In the known from the prior art welds a direct production of the connection between Pile-stopper and Eckstielen at the erection of the tower is not possible because welded joints are more complicated to manufacture. The welds must also be inspected and usually required to be approved by the certifier. Since adhesive and Groutverbindungen these disadvantages do not usually have, the pile stopper can be connected directly to the site or just before loading for shipping to sea with the corner handle and thereby z. B. the use of lining plates for height compensation can be avoided.

Fig. 6 shows in enlarged scale the in Fig. 1 Z area. Shown is the attachment of a cable guide tube 10 via a sleeve 11 at a corner handle 3. To the tubular corner handle 3 is an annular sleeve 11 is placed, with an annular gap remains between Eckstiel 3 and sleeve 11, which is filled with an adhesive 12. After setting of this compound layer forming adhesive 11 is between cuff 11 and corner post 3 a firm connection that does not affect the stability of the corner post 3. On the sleeve 11, the cable guide tube 10 is welded.

The sleeve 11 may, for. B. be composed of several partial rings. Conceivable z. B. two 180 ° partial rings, three 120 ° partial rings or four 90 ° partial rings. Also combinations with different partial rings are possible. It is also possible that the sleeve 11 surrounds the tubular corner post 3 only in a partial circumference, z. B. by 90 °. The size of the adhesive surface must be only the Meet stability requirements for attachment of the secondary structure. These requirements are z. B. at a cable guide tube 10 is less than a work platform. For high stability requirements, therefore, a cuff 11 completely enclosing the corner post 3 is preferred.

Claims (19)

1. Distributed support structure (1) for a wind turbine, in particular a lattice tower structure for a wind turbine, in particular a foundation structure for a wind turbine, in particular for the ground anchoring of an offshore wind turbine via driven foundation piles (5) in the ground (6), wherein the distributed support structure (1) has primary structures (3, 4) via which loads which arise in the support structure (1) on account of the wind turbine are dissipated, and secondary structures (8, 9, 10) which do not have load-dissipating functions but functional functions, wherein the secondary structures (8, 9, 10) are arranged on the primary structures (3, 4) and are cohesively connected thereto, characterized in that the cohesive connection between the primary (3, 4) and the secondary structure (8, 9, 10) is formed as a connecting layer (12, 28, 34) arranged in between.
2. Distributed support structure (1) according to Claim 1, characterized in that the connecting layer is formed as an adhesive layer (12, 28).
3. Distributed support structure (1) according to Claim 1 or 2, characterized in that the secondary structure (10) is fastened, in particular by welding, to a sleeve (11) which rests against the primary structure (3, 4) in a form-fitting manner, wherein the connecting layer (12, 28) is formed between the sleeve (11) and the primary structure (3, 4).
4. Distributed support structure (1) according to Claim 3, characterized in that the sleeve (11) is formed in a multipart manner.
5. Distributed support structure (1) according to Claim 3 or 4, wherein the primary structure (3, 4) is formed in a tubular manner, characterized in that the sleeve (11) is formed as a part shell.
6. Distributed support structure (1) according to Claim 5, characterized in that the sleeve (11) forms a complete ring together with other sleeves or with one or more auxiliary shells.
7. Distributed support structure (1) according to one of the preceding claims, characterized in that the distributed support structure (1) is a foundation structure, the primary structure is a corner post (3) or a leg, and the secondary structure is a pile stopper (8, 9) for limiting the depth of the corner post (3) or leg upon insertion into driven foundation piles (5).
8. Distributed support structure (1) according to Claim 7, characterized in that the pile stopper (8, 9) completely encloses the corner post (3) or the leg, forming an annular gap (33), wherein the connecting layer (12, 28, 34) is arranged in the annular gap (33).
9. Distributed support structure (1) according to Claim 8, characterized in that the pile stopper (8, 9) is constructed from a plurality of partially annular segments, in particular of identical construction.
10. Distributed support structure (1) according to one of Claims 7 to 9, characterized in that the pile stopper (8, 9) is constructed from a bottom pile-stopper annular plate (24, 40) having a central through-hole for the corner post (3) or the leg, from a cylindrical extension (29, 41) that is arranged on the annular inner side of the pile-stopper annular plate (24, 40) and surrounds the through-hole, and from a plurality of reinforcement fins (24c) which are arranged in a manner extending radially outwards, preferably in a delta-shaped manner, between the pile-stopper annular plate (24, 40) and the extension (29, 41), around the circumference of the extension (29, 41) that is substantially perpendicular to the pile-stopper annular-plate plane, wherein the pile-stopper annular plate (24, 40) is dimensioned so as to jut out radially with respect to the foundation pile (5) with the corner post (3) or leg inserted into a foundation pile (5).
11. Distributed support structure (1) according to one of Claims 8 to 10, characterized in that spacers are arranged on the annular-gap-side cylindrical surface of the pile stopper (8, 9), the corner post (3) or the leg being kept at a distance from the pile stopper (8, 9) via said spacers.
12. Distributed support structure according to one of Claims 1 to 5, characterized in that the secondary structure is a cable guide tube (10) or a mooring.
13. Method for producing a distributed support structure (1) for a wind turbine, in particular a lattice tower structure for a wind turbine, in particular a foundation structure for a wind turbine, in particular for the ground anchoring of an offshore wind turbine via foundation piles (5) in the ground (6), wherein the distributed support structure (1) has primary structures (3, 4) via which loads which arise in the support structure (1) on account of the wind turbine are able to be dissipated, and secondary structures (8, 9, 10) which do not fulfil load-dissipating functions but functional functions, wherein at least one primary structure (3, 4) is connected to a secondary structure (8, 9, 10) via cohesive connection, characterized in that the cohesive connection between the primary (3, 4) and the secondary structure (8, 9, 10) is formed as a setting connecting layer (12, 28, 34) arranged in between.
14. Method according to Claim 13, characterized in that the connecting layer is realized as an adhesive layer (12, 28).
15. Method according to Claim 13 or 14, characterized in that the secondary structure (10) is fastened to a sleeve (11) which is attached to the primary structure (3, 4) in a form-fitting manner, and wherein the connecting layer (12, 28, 34) is realized between the sleeve (11) and primary structure (3, 4).
16. Method according to the preceding claim, characterized in that the secondary structure (10) is fastened to the sleeve (11) before the sleeve (11) is connected to the primary structure (3, 4).
17. Method according to either of Claims 13 and 14, characterized in that the secondary structure is a pile stopper (8, 9) and the primary structure is a corner post (3) or leg.
18. Method according to Claim 17, characterized in that, before the pile stopper (8, 9) is connected to the corner post (3) or the leg, the pre-driven foundation pile (5) is calibrated in order to determine the suitable position of the pile stopper (8, 9) on the corner post (3) or leg, and in that the pile stopper (8, 9), in particular offshore, is fastened to the corner post (3) or leg at the determined suitable position.
19. Method according to one of the preceding Claims 13 to 18, characterized in that, in order to improve the shear stability in the region of the connecting layer, in particular when use is made of grout (34), shear connectors, in particular shear keys (27, 35), are arranged.

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