WO2017046624A1

WO2017046624A1 - Circumferential segment of a concrete ring for forming a support mast

Info

Publication number: WO2017046624A1
Application number: PCT/IB2015/001970
Authority: WO
Inventors: Benoît Melen; Nicolas FABRY
Original assignee: Soletanche Freyssinet
Priority date: 2015-09-17
Filing date: 2015-09-17
Publication date: 2017-03-23

Abstract

Circumferential segment of a concrete ring for forming a support mast A circumferential segment of a concrete ring for forming a mast comprising a plurality of superimposed concrete rings (6), said segment (8, 10) comprising a circumferential end (8₁, 10₁) destined to cooperate with a circumferential end (8₁, 10₁) of complementary shape belonging to another segment (8, 10) of said concrete ring (6) to form a circumferential joint of said concrete ring, said circumferential end comprising at least one first reception port (16) for receiving a first shear pin (18) configured to take up at least shear efforts applied to said circumferential joint. Corresponding concrete ring, support mast and manufacturing method.

Description

Circumferential segment of a concrete ring for forming a support mast

The invention relates to the manufacturing of support masts, such as masts used to support wind turbine nacelles.

A typical design of such masts revolves around superimposing concrete rings to a desired height, for instance greater than 100 m.

Given the strains the mast is subjected to, the elementary rings used to form the mast are of sizeable dimensions.

A commonly used approach to manufacture these rings consists in cast-molding the rings in one piece, which results in rings offering good mechanical properties. However, this approach also has drawbacks: the obtained rings are bulky and must be handled with extreme care in order to prevent their deterioration. These considerations result in these rings being inadequate for transportation, and therefore usually have to be manufactured on the mast construction site.

In order to address these problems, alternative approaches have been envisaged. Some of them lie in manufacturing the rings by re-assembling initial circumferential segments which have been parted from one another.

A major concern in these approaches revolves around obtaining assembled rings which exhibit mechanical properties identical to those obtained through the previous approach, in particular around the joints which are formed when the different segments of the rings are assembled together. To that end, the current state-of-the art techniques used to form the joints between different segments of a given ring consist in forming a concrete keying joint between the two segments, which, once hardened, provides a good mechanical resistance to efforts applied to the joint, such as shearing efforts that tend to part the segments from one another.

However, these techniques also present drawbacks. In fact, the time required for the drying of the concrete of the keying joint is long, which negatively impacts the amount of time required to build the support mast, all the more so as the mast may comprise a great number of superimposed rings.

The invention therefore seeks to improve the situation.

To that end, the invention relates to a circumferential segment of a concrete ring for forming a mast comprising a plurality of superimposed concrete rings, said segment comprising a circumferential end destined to cooperate with a circumferential end of complementary shape belonging to another segment of said concrete ring to form a circumferential joint of said concrete ring, said circumferential end comprising at least one first reception port for receiving a first shear pin configured to take up at least shear efforts applied to said circumferential joint.

According to an aspect of the invention, the circumferential end further comprises at least one second reception port for receiving a second shear pin configured to take up at least shear efforts applied to said circumferential joint.

According to an aspect of the invention, at least one first reception port stretches along a direction contained in a circumferential section plane of said segment, said direction being parallel to a tangential plane to said segment in said circumferential section plane. According to an aspect of the invention, the circumferential end comprises an alternation of tenons and mortises, the circumferential end comprising a plurality of first receiving ports for receiving said shear pin, said first reception ports being arranged in said tenons and being aligned with one another.

According to an aspect of the invention, the tenons comprise side faces which are horizontally bowed with respect to the circumference of said segment. According to an aspect of the invention, the side faces of said tenons are horizontally bowed with respect to the circumference of said segment with an angle equal to or inferior to 10°.

According to an aspect of the invention, the segment further comprises at least one reinforcement bar having a portion which surrounds said first reception port.

The invention further relates to a concrete ring for forming a mast comprising a plurality of superimposed concrete rings, said concrete ring comprising at least a first circumferential segment and a second circumferential segment as defined above, the respective circumferential ends of the first, respectively the second circumferential segments being of complementary shape and cooperating with one another to define a circumferential joint of said concrete ring, the at least one first reception port of the circumferential end of the first circumferential segment being aligned with the at least one first reception ports of the circumferential end of the second circumferential segment, said concrete ring further comprising a first shear pin inserted in the first reception ports of said circumferential ends of first and second circumferential segments and being arranged to take up at least shear efforts applied to said circumferential joint.

According to an aspect of the invention, the circumferential ends of the first and second circumferential segments further comprise each at least one second reception port, the second reception ports of the circumferential ends of the first and second circumferential segments being aligned with one another, the concrete ring further comprising at least one second shear pin received in the second reception ports of the circumferential ends of the first and second circumferential segments and arranged to take up at least shear efforts applied to said circumferential joint.

According to an aspect of the invention, the first and second reception ports are spaced apart radially.

According to an aspect of the invention, the first and second reception ports are spaced apart circumferentially .

According to an aspect of the invention, the first shear pin is sealed inside said first reception ports.

The invention further relates to a support mast for supporting a wind turbine, said support mast comprising a plurality of superimposed concrete rings, the support mast comprising at least one concrete ring as defined above.

The invention further relates to a method of manufacturing a concrete ring as defined above, said method comprising:

- obtaining a first circumferential segment and a second segment circumferential each having a circumferential end having a shape complementary of that of the circumferential end of the other circumferential segment, said circumferential ends each comprising at least one first reception port,

- arranging the circumferential ends in contact in one another to form a circumferential joint of the concrete ring and so that the first reception ports of the circumferential ends of the first and second circumferential segments are aligned, and

- inserting a shear pin in the first reception ports of the circumferential ends of the first and second circumferential segments to take up at least shear efforts applied to said circumferential joint.

According to an aspect of the invention, the method further comprises sealing the shear pin inside the first reception ports.

According to an aspect of the invention, the method further comprises sealing the first and second circumferential ends together.

According to an aspect of the invention, the method further comprising manufacturing the first and second circumferential segments using a cast and a separation element arranged in said cast to define the respective circumferential ends of the first and second circumferential segments.

According to an aspect of the invention, manufacturing the first and second circumferential segments comprises :

- arranging one or more rods inside the cast and through holes of the separation element to form the first reception ports, - pouring concrete in the cast,

- removing the one or more rods after the poured concrete has hardened.

According to an aspect of the invention, the one or more rods comprise said first shear pin.

Further features and advantages of the invention will become more apparent by reading the following detailed description of the embodiments, which are given by way of non-limiting examples with reference to the appended drawings, in which:

- Figure 1 illustrates a support mast according to the invention;

- Figures 2a, 2b and 2c illustrate a concrete ring according to the invention;

- Figure 3 illustrates a sectional view of a circumferential end of a circumferential segment of a concrete ring according to the invention;

- Figure 4 illustrates a manufacturing process of a concrete ring and of a support mast according to the invention;

- Figure 5 illustrates a cast and a separation element used during the process of Figure 4; and

- Figure 6 illustrates a concrete ring according to an alternative embodiment of the invention. Figure 1 illustrates a support mast 2 according to the invention.

The support mast 2 is for instance destined to support a wind turbine nacelle 4.

The support mast 2, or mast 2, comprises a plurality of superimposed rings 6. At least one of the rings 6 is a ring according to the invention.

In reference to Figures 2a to 2c, a ring 6 according to the invention presents an annular shape.

More precisely, the ring 6 presents a cylindrical shape stretching circumferentially around a central axis X (Figure 2b).

For instance, the ring 6 has a straight cylindrical shape. In other words, his surface is generated by a line which is parallel to the central axis X.

Alternatively, the ring 6 may have a frustoconical cylindrical shape. In other words, the surface of the ring is generated by a line which is not parallel to the central axis.

Advantageously, the ring 6 is made of concrete, and preferably of reinforced concrete. This is further detailed below. In further reference to Figures 2a to 2c, the ring 6 comprises at least two separate circumferential segments 8, 10.

These segments 8, 10 each form a portion of the circumference of the ring 6. The segments make-up the ring once assembled together. The ring 6 may solely comprise two segments, as in Figures 2a to 2c, or more than two segments.

In the example of the Figures, the ring 6 comprises a first circumferential segment 8, hereafter first segment 8, and a second circumferential segment 10, hereafter second segment 10.

The first and second segment 8, 10 each comprise a first circumferential end 8_l5 10i respectively, hereafter first end 8 10i. The first ends 8 10i are destined to be coupled to one another in a coupled configuration to form a circumferential joint J (Figure 1 and 2c) of the ring 6. To that end, the first ends 8 10i are of complementary shape.

For instance, each first end 8 10i comprises at least one tenon 12 and one mortise 14 destined to cooperate with a complementary mortise 14 and tenon 12 of the first end of the other segment. Advantageously, each first end 8 10i comprises alternation of tenons 12 and mortises 14 destined to cooperate with complementary mortises 14 and tenons 12 present on the other first end 8_l5 10i.

Advantageously, this alternation of tenons and mortises runs along the entire first end, i.e. from the top extremity of the first end to the bottom extremity of the first end (given the orientation of the Figures) .

The tenons 12 and mortises 14 present themselves in the form of protrusions, respectively grooves extending circumferentially with respect to the central axis X. The tenons 12 extend circumferentially away from a central portion 8_C, 10_c of the corresponding segment 8, 10, whereas the mortises 14 extend circumferentially towards this central portion 8_C, 10_c.

In the coupled configuration, the tenons of a given first end 8, 10 are engaged in the mortises of the other first end and are in abutment in the latter. In reference to Figure 3, the tenons 12 comprise side faces 12F which are oriented along the generation line of the corresponding segment, i.e. toward the top or the bottom of Figure 3. The side faces 12F are further horizontally bowed with respect to the circumference of the corresponding segment 8, 10. In view of the orientation of Figure 3, the side faces 12F are thus bowed relative to a horizontal plane. Preferably, the bowing angle a of the side faces 12F is inferior to or equal to 10°. Advantageously, this angle a is inferior or equal to 5°, and is for instance comprised in the range [3°; 5°] .

Given the complementary shape of the first ends 8i, 10i and given that the side faces 12F of the tenons also correspond to the side faces of the neighboring mortises, the mortises themselves present side faces which are bowed with respect to the circumference of the segment 8, 10.

In the context of the invention, the segments 8, 10 further comprise at least one first reception port 16 for receiving a shear pin 18 configured to take up at least shear efforts applied to the joint J formed by the first ends 8i, 10i.

The first reception ports 16 are arranged in the first end 8i, 10i of the corresponding segment 8, 10. In the example of Figures 2a to 2c, each first end 8 10i comprises, for at least one tenon 12, a first reception port 16 which traverses the tenon 12 from one side face 12F to the opposite side face 12F.

Advantageously, the first end 8_l5 10i comprises, for each tenon 12, a first reception port 16 which traverses the tenon 12 from one side face 12F to the opposite side face 12F.

The first reception ports 16 of a given first end 8_l5 10i are aligned with one another. Moreover, the first reception ports 16 are arranged so that when the first ends 8_l5 10i of the segments 8, 10 are in coupled configuration, the first reception ports 16 of the first ends of both segments 8, 10 are all aligned.

In reference to Figure 3, the first reception ports 16 present a straight cylindrical shape. The reception ports 16 are preferably through-holes.

Advantageously, they extend along a direction which is contained in a circumferential section plane of the corresponding segment 8, 10, i.e. a radial plane with respect to axis X. In this section plane, the direction of the reception ports 16 is parallel to the tangential plane of the segment.

In other words, the reception ports 16 are arranged in parallel to the generation line of the considered ring 6. For a straight cylindrical ring 6, the reception ports 16 thus extend vertically.

Advantageously, the segments 8, 10 further comprises second reception ports 20 for receiving a second shear pin 22 designed to take up at least shear efforts applied to the joint J (Figure 2a).

The second reception ports 20 present a configuration analogous to that of the first reception ports 16. In other words, for a given segment, they are located on the first end and are arranged to be aligned with one another on that first end. In addition, the complementary first end of the other segment destined to form the joint J along with the considered segment also comprises second reception ports 20 arranged to be aligned among each other. The second reception ports 20 of the first ends of the two segments are arranged to be aligned when the first ends are in the coupled configuration. For a given first end 81, lOi, the first and second reception ports 16 are spaced apart. They may be spaced apart radially relative to the central axis X. They may also or alternatively be spaced apart circumferentially around that axis X.

Advantageously, the second reception ports are located in the neighborhood of the first reception ports. For instance, they are also arranged in the tenons of the first end.

In reference to Figures 2a to 2c, the shear pins 18, 22 are destined to be inserted in the first reception ports 16 (and second reception ports 20 if any) to take up at least shear efforts applied to the joint J in which they are inserted. They thus form shear keys.

In particular, they are configured to take up shear efforts that tend to move the corresponding segments away from one another, and thus contribute to prevent a possible dislocation of the ring 6 around the joint J once the segments have been assembled.

The shear pins 18, 22 are for instance made of highly adherent steel.

They comprise a rod portion 18R which is to be inserted in the reception ports. The rod portion 18R presents dimensions roughly complementary of that of the corresponding reception port, in particular in terms of diameter.

Advantageously, the rod portion 18R presents a length which is adapted to have the rod portion in a flush configuration relative to the reception ports. In other words, once inserted in the reception port, the rod portion 18R is more or less entirely contained in the reception ports of the cooperating first ends of the considered segments and more or less entirely fills the reception ports. In other words, advantageously, the rod portion 18R is as high as the ring itself.

The rod portion 18R advantageously comprises a diameter between 10 and 40 mm.

The rod portion 18R advantageously presents a length comprises between 20 and 100 cm.

The shear pins 18, 22 may further comprise a handle portion 18H which protrudes from the segments, for instance above the segment. In reference to Figure 3, the segments 8, 10 further comprise reinforcement bars 24 configured to enhance the mechanical properties of the segments.

These bars 24 are preferably arranged within the matter of the segment. The bars 24 are for instance made of steel.

The bars 24 include circumferential bars 24H which stretch along the circumference of the considered segment. The bars 24 further include bars 24V which are arranged perpendicularly to the circumferential bars 24H. The bars 24V thus stretch in a direction parallel to the generation line of the considered segment. The bars 24H and 24V may be coupled together to enhance the distribution of the efforts they take up within the segment.

In the context of the invention, at least one reinforcement bar 24H comprises a portion 24S (Figure 3) which surrounds a first reception port 16 of the first end.

More specifically, the portion 24S presents a U-shape whose central portion is arranged between the corresponding reception port 16 and the extremity of the segment, and whose legs stretch towards the central portion of the segment.

The corresponding bar 24H for instance presents a first extended portion stretching in the matter of the segment, followed by the portion 24S which surrounds the reception port and which passes between the reception port and the extremity of the segment, itself followed by a second extended portion stretching parallel to the first extended portion and side-to-side with the latter. Alternatively, it may solely comprise the first extended portion and the portion 24S.

Preferably, the segment comprises, for each reception port, at least one reinforcement bar 24H which surrounds the considered reception port of the first end. For instance, it comprises two or more reinforcement bars 24H for every reception port 16.

In embodiments in which the segment comprises first and second reception ports, the reinforcement bar 24H advantageously also surrounds the neighboring second reception port.

The above description has been given to illustrate the configuration of a given joint J of the ring 6. However, this configuration may also be implemented for every joint J of the ring which results from the assembling of the segments that are to make-up the ring once assembled together.

In other words, advantageously, the segments 8, 10 further comprises a second circumferential end 8₂, 10₂, or second end, 8₂, 10₂ opposite of the first end 8i, 10i and which presents a configuration identical to that of the first end 8i, 10i. In other words, the second end 8₂, 10₂ is destined to cooperate with a circumferential end of complementary shape belonging to another segment of the ring, whether the other segment 8, 10 or another segment if the ring comprises more than two segments, in order to form another joint J.

The second end advantageously also comprises tenons and mortises as described above. It further comprises first reception ports 16 which are aligned to receive a shear pin 18, 22. These ports are preferably arranged in the tenons. Optionally, it further comprises second reception ports 20 which are also aligned and are arranged to receive a further shear pin. They are spaced apart radially and/or circumferentially from the first reception ports. The segment also comprises at least one reinforcement bar which surrounds a first reception port of the second end in the manner described above, and preferably comprises such a reinforcement bar for every first reception port.

A method for manufacturing a ring according to the invention and for building a support mast according to the invention will now be described in reference to the Figures for an embodiment in which the ring only comprises two segments, the transposition to embodiments in which it comprises more than two segments being immediate.

During a first step SI, the segments 8, 10 of the ring are manufactured.

In reference to Figure 5, this step is carried using a cast 26 which defines an inner cavity having the general shape which is desired for the ring 6.

The cast 26 is for instance made of metal.

The cast 26 further comprises, for each joint J of the ring 6, a separation element 28 arranged in the cast to form the respective complementary shapes of the first ends 8i, 10i of the two segments.

The separation element 28 presents itself in the form of a thin plate of desired shape and is arranged vertically in the cast. The thickness of the separation element 28 may be of a few millimeters or less.

In the example of Figure 5, the separation element 28 has a geometry configured to define the tenons and mortises of the first ends 8 10i.

The separation element 28 comprises holes 30 arranged to form, in conjunction with a rod 32, the first reception ports 16 once the cast has been filled and the poured material has hardened. The holes 30 are aligned in the desired configuration (for instance vertically in the cast for a straight cylindrical ring, or in the configuration described above for a frustoconical ring).

Advantageously, the rod 32 corresponds to the shear pin 18, 22 destined to be received in the joint once the ring has been assembled. Alternatively, the rod 32 may be distinct from the shear pin.

If the segments are to comprise second reception ports, the separation element 28 comprises a corresponding number of holes arranged in the appropriate configuration.

Once the separation elements 28 have been arranged in the cast, the rod 32 in inserted in the cast through the separation element 18 via the holes 30.

The reinforcement bars 24 are also installed in the cast in the desired configuration, either sequentially with the separation element 28 or at the same time. Concrete is then poured in the cast 26 and fills the latter. Once the concrete has hardened, the rod 32 is removed, thereby clearing the reception ports, and the newly formed segments are extracted from the cast.

They may then be moved to another site for assembling. During a step S2, the segments of the ring obtained via step S 1 are assembled together to form the ring 6.

To that end, the ends of the segments are arranged in abutment with the complementary ends of the other segments so as to form the general shape of the ring and are sealed in this configuration. In the example of Figures 2a to 2c, the first ends 8i, 10i are pushed together so that the extremities of the tenons of one first end abut in the corresponding mortises of the other first end, and so are the second ends 8₂, 10₂.

For the sealing of the ends together, the ends are for instance coated with a glue or mortar prior to being pushed against one another. The glue is for instance epoxy glue. The mortar is for instance a liquid mortar. For every end of every segment, the shear pins 18, 22 are then inserted in the corresponding reception ports 16, 20 which have thus been aligned. The shear pins 18, 22 are then sealed in the reception ports.

To that end, a mortar or a resin is poured in the reception ports once the shear pins have been inserted.

Once these tasks have been performed, the joints J of the ring are formed and the ring is assembled.

Once the ring 6 has been assembled, the ring 6 may be used to manufacture the support mast 2. To that end, during a step S3, it is installed on top of the previously installed rings of the support mast 2.

If needed, for instance in embodiments in which the shear pins of the ring located on top of the pile of the previously installed rings comprise a handle portion 18H, this installation includes arranging grooves in the bottom surface of the ring to be installed in which the handle portions 18H of the ring below it may be received.

The invention presents many advantages.

In particular, it eases the transportation of the rings, as they are made of smaller segments, while negating the impact that the reassembling of the rings may have over their mechanical properties.

In addition, the use of mortises and tenons contributes favorably to these properties. Having a plurality a shear pins further increases the mechanical properties of the joints J, in particular when under stresses which tend to part the segments radially.

Moreover, having reinforcement bars which surround the reception ports enhances the transmission of efforts applied to the shear pins to the rest of the segment. Many modifications and variations of the present invention are made possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

In particular, in an alternative embodiment illustrated in Figure 6, the ends of the segment may present a shape other than that of an alternation of tenons and mortises. For instance, the ends present a beveled shape.

In addition, in the description above, the reception ports 16, 20 have been described as being formed directly by the rods 32.

However, in some embodiments, in order to ease the removal of the segments from the cast, each reception port 16 contains a sheath 16S (Figure 3, in which a single sheath is represented) which forms a wall of the corresponding reception port.

Each sheath presents a shape identical to that of the hole it is arranged in. In other words, it presents the same height and its extremities are conformed to match the geometrical configuration of the opening of the port.

The sheaths present for instance a hollow cylindrical shape. In order to account for the geometrical configuration of the opening of the port which are for the most part located on the side faces 12F which may be beveled, one or both of its extremities may be beveled as well if the side faces 12F are.

In addition, it presents dimensions, in particular a diameter, complementary of that of the rods 32 and of the shear pin 18, 22 it is intended to receive. Thus, the efforts applied to the shear pin are more efficiently distributed over the concrete surrounding the reception port and against which the sheath is arranged.

For the manufacturing of the ring, for each joint J, the sheaths of the reception ports of both considered ends are inserted in the cast along with the rod(s) 32 prior to the concrete being poured.

Given the construction sequence of a given segment, the sheaths present by construction an external diameter complementary of that of the corresponding reception port.

Claims

1. Circumferential segment of a concrete ring for forming a mast comprising a plurality of superimposed concrete rings (6), said segment (8, 10) comprising a circumferential end (8i, 10i) destined to cooperate with a circumferential end (8 10^ of complementary shape belonging to another segment (8, 10) of said concrete ring (6) to form a circumferential joint (J) of said concrete ring, said circumferential end comprising at least one first reception port (16) for receiving a first shear pin (18) configured to take up at least shear efforts applied to said circumferential joint.

2. Segment according to claim 1, wherein the circumferential end (8i, 10i) further comprises at least one second reception port (20) for receiving a second shear pin (22) configured to take up at least shear efforts applied to said circumferential joint.

3. Segment according to claim 1 or 2, wherein at least one first reception port (16) stretches along a direction contained in a circumferential section plane of said segment, said direction being parallel to a tangential plane to said segment in said circumferential section plane .

4. Segment according to any one of the preceding claims, wherein said circumferential end comprises an alternation of tenons (12) and mortises (14), the circumferential end comprising a plurality of first receiving ports (16) for receiving said shear pin, said first reception ports being arranged in said tenons (12) and being aligned with one another.

5. Segment according to claim 4, wherein said tenons comprise side faces (12F) which are horizontally bowed with respect to the circumference of said segment.

6. Segment according to claim 5, wherein the side faces (12F) of said tenons are horizontally bowed with respect to the circumference of said segment with an angle equal to or inferior to 10°.

7. Segment according to any one of claims 1 to 6, wherein said segment further comprises at least one reinforcement bar (24) having a portion (24S) which surrounds said first reception port.

8. A concrete ring for forming a mast comprising a plurality of superimposed concrete rings, said concrete ring (6) comprising at least a first circumferential segment (8) and a second circumferential segment (10) according to any one of claims 1 to 7, the respective circumferential ends (8i, 10i) of the first (8), respectively the second (10) circumferential segments being of complementary shape and cooperating with one another to define a circumferential joint (J) of said concrete ring, the at least one first reception port (16) of the circumferential end of the first circumferential segment (8) being aligned with the at least one first reception ports (16) of the circumferential end ( 10i) of the second circumferential segment, said concrete ring further comprising a first shear pin (16) inserted in the first reception ports (16) of said circumferential ends of the first and second circumferential segments and being arranged to take up at least shear efforts applied to said circumferential joint.

9. A concrete ring according to claim 8, wherein the circumferential ends of the first and second circumferential segments further comprise each at least one second reception port (20), the second reception ports of the circumferential ends of the first and second circumferential segments being aligned with one another, the concrete ring further comprising at least one second shear pin (22) received in the second reception ports of the circumferential ends of the first and second circumferential segments and arranged to take up at least shear efforts applied to said circumferential joint.

10. A concrete ring according to claim 9, wherein the first and second reception ports are spaced apart radially.

11. A concrete ring according to claim 9 or 10, wherein the first and second reception ports are spaced apart circumferentially.

12. A concrete ring according to any of claims 8 to 11, wherein the first shear pin (18) is sealed inside said first reception ports.

13. A support mast for supporting a wind turbine, said support mast comprising a plurality of superimposed concrete rings, wherein the support mast comprises at least one concrete ring (6) according to any one of claims 8 to 12.

14. A method of manufacturing a concrete ring according to any of claims 8 to 12, said method comprising:

- obtaining a first circumferential segment (8) and a second segment circumferential (10) each having a circumferential end (8i, 10i) having a shape complementary of that of the circumferential end of the other circumferential segment (8, 10), said circumferential ends each comprising at least one first reception port (16),

- arranging the circumferential ends of the first and second circumferential segments in contact in one another to form a circumferential joint (J) of the concrete ring and so that the first reception ports (16) of the circumferential ends of the first and second circumferential segments are aligned, and

- inserting a first shear pin (16) in the first reception ports of the circumferential ends of the first and second circumferential segments to take up at least shear efforts applied to said circumferential joint.

15. The method of claim 14, the method further comprising sealing the shear pin (16) inside the first reception ports.

16. The method of claim 14 or 15, the method further comprising sealing the first and second circumferential ends (8i, 10i) together.

17. The method of any one of claims 14 to 16, the method further comprising manufacturing the first and second circumferential segments using a cast (26) and a separation element (28) arranged in said cast to define the respective circumferential ends of the first and second circumferential segments.

18. The method of claim 17, wherein manufacturing the first and second circumferential segments comprises :

- arranging one or more rods (32) inside the cast (26) and through holes (30) of the separation element to form the first reception ports,

- pouring concrete in the cast,

- removing the one or more rods (32) after the poured concrete has hardened.

19. The method according to claim 18, wherein the one or more rods (32) comprise said first shear pin (16).