Precast concrete dowel, wind turbine tower comprising said dowel, wind turbine comprising said tower and method for assembling said wind turbine

1. A precast concrete dowel comprising:

an upper surface,

a lower surface,

an inner side surface, and

an outer side surface;

the dowel further comprising:

at least an intermediate fixing surface, located in one of the side surfaces, between the upper and lower surfaces,

at least a first groove made in the side surface comprising the intermediate fixing surface, wherein the first groove communicates the intermediate fixing surface with one of the upper and lower surfaces and is configured to accommodate joining cables;

at least an inner longitudinal duct which runs inside the dowel between an inlet hole and an outlet hole, and

joining cables configured to join the dowel, and which are accommodated in at least a duct;

wherein the inlet hole and/or the outlet hole are inside a second groove communicating the inner side surface or the outer side surface with one of the upper or lower surfaces, the second groove being configured to accommodate the joining cables.

2. The dowel of claim 1 , further comprising a protuberance located near the upper surface or the lower surface comprising the first groove, in such a way that the dowel has a distance between the inner and outer side surfaces which is bigger in the protuberance than in the rest of the dowel, wherein the intermediate fixing surface lies within a first face of the protuberance.

3. The dowel of claim 1 , further comprising a first cavity which intercepts one of the inner or outer side surfaces, wherein the first cavity is limited at least by the intermediate fixing surface, and the width of the first cavity is bigger than the width of the first groove.

4. The dowel of claim 1 , wherein the intermediate fixing surface forms an angle different to 90° from the corresponding side surface.

5. The dowel of claim 1 , comprising a plurality of ducts and a plurality of first grooves, wherein at least one of the first grooves is arranged between two adjacent ducts.

6. The dowel of claim 1 , wherein the inlet hole and/or outlet hole are located, at least partially, on the outside of the upper or lower surface comprising the plurality of first grooves.

7. The dowel of claim 1 , wherein the inlet hole and/or the outlet hole are in the inner side surface.

8. A wind turbine tower comprising a plurality of dowels, wherein the plurality of dowels comprises the dowel described in claim 1 , and wherein between two adjacent dowels, a plurality of ducts from one of the dowels and a plurality of first grooves of the adjacent dowel are collinear.

9. The wind turbine tower of claim 8 , further comprising:

fixing elements intended to provide a fixing between the joining cables from one dowel, and the intermediate fixing surface of the adjacent dowel; and

load sharing elements located on the intermediate fixing surface on which the fixing elements are located, the load sharing elements being pressed by the fixing elements, for evenly distributing strain on the intermediate fixing surface.

10. A wind turbine comprising the tower described in claim 9 .

11. The wind turbine of claim 10 , further incorporating a nacelle comprising an upper flange for connecting the nacelle to the tower, wherein the upper flange is provided with third grooves to accommodate the joining cables of a dowel.

12. The wind turbine of claim 10 , further incorporating a foundation comprising fourth grooves to accommodate the joining cables of a dowel.

13. The wind turbine of claim 10 further comprising:

fixing elements intended to provide fixing between the joining cables from a dowel and the intermediate fixing surface; and

load sharing elements located on the intermediate fixing surface, and pressed by the fixing elements, to evenly distribute the stresses of the joining cables on the intermediate fixing surface,

wherein the fixing elements and the load sharing elements are configured so as to fix the joining cables of at least a dowel, in such a way that they are arranged over a fixing surface located either in a second dowel or in the upper flange or in the foundation.

14. The precast concrete dowel of claim 1 , wherein the dowel comprises a dowel body, and wherein the upper surface, the lower surface, the inner side surface, the outer side surface, the at least one intermediate fixing surface and the at least one first groove are comprised on the dowel body.

15. A method for assembling a wind turbine, comprising a stage of fixing a dowel as described in claim 1 to a component of the wind turbine selected from a list consisting of:

an upper flange;

a foundation; and

an adjacent dowel;

wherein the stage of fixing a dowel to a component of the wind turbine comprises the following steps:

separating the joining cables from an area of access to said component, additionally fastening said joining cables with provisional fastening means,

bring the dowel near the component;

release the provisional fastening means;

accommodate the joining cables in grooved housings of the component; and

fixing the joining cables using the fixing elements.