[0001] The invention relates to a connecting element for a radial reinforcement structure of a tower structure, the reinforcement structure comprising main reinforcements extending radially on the same level from the centre toward the edges and connecting reinforcements arranged to bind the main reinforcements relative to each other. The invention further relates to a radial reinforcement structure for a tower structure, the reinforcement structure comprising main reinforcements extending radially on the same level from the centre toward the edges and connecting reinforcements arranged to bind the main reinforcements relative to each other.

[0002] In many cases, the tower structures are quite difficult structures in view of their foundation. In this context, tower structures refer to masts, towers and corresponding structures. A particular example of structures with which there are often difficulties are wind power plants, for which today quite high towers need to be built. The high towers of wind power plants are subjected to high loads, whereby high demands are set for the foundations of the towers.

[0003] For the above reasons, it is in many cases necessary to design too much reinforcement for tower structure foundations of wind power plants, because the reinforcement is for the sake of its simplicity often made three-dimensional, that is, in the x-y coordinate system. Drawbacks with solutions of this type are high material costs.

[0004] Radial reinforcement solutions are also known in the field. An optimal solution in connection with radial reinforcement solutions would be a complete radial reinforcement extending from the centre toward the edges. However, such a reinforcement is difficult to implement. In practice, the difficulties arise from the number of reinforcements. In radial foundation reinforcement, the number of radial reinforcement bars, that is, the main reinforcements, is typically 100 to 200 pieces. The reinforcement bars must be anchored in some way to the opposite sides of the reinforcement centre. In practice, this leads to an impossible situation, because these 100 to 200 pieces would intersect at the same point, that is, at the centre point of the radial reinforcement. Because the reinforcement bars are 10 to 32 mm thick, the layering of the reinforcement bars in the area of the reinforcement centre point would be 200 to 600 mm, which is not possible in practice. [0005] Due to the above reasons, in practical solutions implemented with radial reinforcements, the reinforcement is ended freely before the centre point. The forces are then anchored for instance to the tower of the wind power plant that is partly embedded in concrete. A drawback of such a solution is that both vertical forces of the tower and transverse forces caused by the reinforcement load the tower. This type of situation causes additional stress to the parts of the tower.

[0006] Structures described in published US patent 7 155 875, PCT publication WO 2005/015013 A1 and published EP application 1 526 278 A1 are general examples of solutions known in the art.

[0007] The purpose of the invention is to provide a solution, by which the prior-art disadvantages can be eliminated. This is achieved by a connecting element and reinforcement structure according to the invention. The connecting element of the invention is characterised in that it is formed of a centre element arranged at the centre point of a radial reinforcement structure, the centre element being equipped with fastening members for fastening the inner ends of the radial main reinforcements positioned on the same level to the centre element. The reinforcement structure of the invention is, in turn, characterised in that the radial reinforcement structure comprises a centre element arranged at the centre point of the reinforcement structure, the centre element being equipped with fastening members for fastening the inner ends of the radial main reinforcements positioned on the same level to the centre element.

[0008] An advantage of the invention is above all its simplicity, which makes the adoption and use of the invention advantageous. The invention also provides the advantage that it permits, in practice, an optimal radial reinforcement solution without the intersections of reinforcements in the area of the centre point, which cause difficulties.

[0009] The invention will be explained in the following in more detail by means of a working example described in the attached drawing, in which

Figure 1 is a general view of a reinforcement structure of the invention,

Figure 2 is a view of the reinforcement structure of Figure 1 in the direction of arrows A-A,

Figure 3 is a perspective view of a connecting element of the invention in a radial reinforcement structure, Figure 4 shows the structure of Figures 1 to 3 in connection with a sector view depicting a three-dimensional reinforcement structure, and

Figure 5 shows the structure of Figure 4 in full.

[0010] Figures 1 and 2 show a general view of the radial reinforcement structure for a tower structure in accordance with the invention. Figure 1 is a top view of the reinforcement structure and Figure 2 is a view in the direction of arrows A-A.

[0011] The tower structure (not shown in Figures 1 and 2) is intended for arrangement in the centre of Figure 1 , for instance, so that the reinforcement is radially around the tower. For a person skilled in the art, this is fully conventional technology, wherefore it is not explained in greater detail herein. In this context, reference is made for instance to the publications cited as the prior art.

[0012] As shown in Figures 1 and 2, the radial reinforcement structure comprises main reinforcements 1 extending radially on the same level from the centre toward the edges and connecting reinforcements 2 arranged to bind the main reinforcements relative to each other. The connecting reinforcements 2 may be circular elements, for example. Both the main reinforcements 1 and connecting reinforcements 2 are elements made of steel, for instance.

[0013] According to an essential idea of the invention, the invention comprises a connecting element that is formed of a centre element 3 arranged at the centre point of the radial reinforcement structure. In the area of the outer edge of the centre element 3 in the example of the figures, fastening members 4 are made for fastening the inner ends of the radial main reinforcements 1 positioned on the same level to the connecting element. The above-mentioned matters are clearly shown in Figure 3.

[0014] In the example of the figures, the centre element 3 is formed of a disc-like element. The use of a round disc has been found especially advantageous. However, the shape of the centre element may be selected freely according to each situation, it is for instance possible to use a star-like or polygonal centre element. Even a triangular centre element is possible.

[0015] As shown in Figures 1 to 3, the disc-like centre element 3 is preferably arranged to be positioned level with the radial main reinforcements 1 . In this context, it should be noted that the centre element 3 need not be a disc-like element, but other shapes, such as three-dimensional shapes, are also possible. The essential thing is that the fastening members on opposite sides of the centre element are substantially level with each other, whereby forces can transfer via the centre element from one reinforcement bar of the main reinforcement to another reinforcement bar on the opposite side of the centre element and back, in other words, the structure can be anchored on opposite sides of the centre.

[0016] The fastening members 4 on the centre element 3 may be any suitable fastening members, for instance members with inner or outer threads, in other words, the edge of a round disc, for instance, has drillings with inner threads and the ends of the reinforcements have corresponding outer threads that are compatible with the inner threads. It is also possible to use fastening members of other type, such as friction-based joints either as such or with a suitable fastening material or procedure. The centre element 3 is preferably made of steel material.

[0017] Figures 4 and 5 show a radial reinforcement structure that is made into a three-dimensional structure. The same reference numbers for the corresponding parts are used in Figures 4 to 5 as in Figures 1 to 3. Figure 4 shows a sector of a three-dimensional reinforcement structure and Figure 5 shows the entire reinforcement. Figures 4 and 5 clearly show that the reinforcement structure comprising the centre element 3 fastening the inner ends of the radial main reinforcement 1 positioned on the same level is a tensile reinforcement that is positioned in the area of the top or/and bottom surface structure of the three-dimensional reinforcement structure.

[0018] The example of Figures 4 and 5 also contains various vertical reinforcement elements 5. For a person skilled in the art, elements of this type are fully conventional technology, wherefore they are not shown in greater detail herein. The reinforcement structure of Figures 4 and 5, that is, the structure formed of reinforcements 1 , 2, 5 is surrounded by concrete in the final structure.

[0019] Figures 4 and 5 also show a cylindrical wall element 6 arranged in the area of the centre part of the reinforcement. The bottom part of the above-mentioned cylindrical element is embedded in concrete in the finished structure. The element in question is a part of a tower in a wind power plant. The element transfers forces directed to the tower into the concrete. For a person skilled in the art, this too is fully conventional technology, wherefore it is not shown in greater detail herein. [0020] The examples shown in the figures are not intended to limit the invention in any way, but the invention may be modified freely within the scope of the claims. The example of the figures shows a solution, in which the radial main reinforcement is on one level. However, this is not the only solution, but the main reinforcement may also be on several levels, for instance on two levels, in which case the inner ends of the radial reinforcement located on two levels are fastened to a centre element, for instance to fastening elements located on two levels and arranged on the edge of a round disc.