JP2021042590A - Hybrid structure - Google Patents

Abstract

To provide a hybrid structure capable of connecting an upper cylindrical body made of steel with a lower cylindrical body made of concrete with a simple configuration.SOLUTION: A hybrid structure is provided with: a lower cylindrical body 12 made of concrete to be erected upward; an upper cylindrical body 20 made of steel to be erected upward from the upper end side of the lower cylindrical body 12, of which a lower end side is inserted in an upper end side cylinder of the lower cylindrical body 12 and a side surface of the lower end side faces a side surface of the upper end side of the lower cylindrical body with a space apart; and a connection part 30 connecting and supporting the lower end side of the upper cylindrical body 20 to the upper end side of the lower cylindrical body 12, wherein the connection part 30 comprises an inner side bearing member 31 projecting in the space from the side surface of the lower end side of the upper cylindrical body 20, an outer side bearing member 35 projecting in the space from the side surface of the upper end side of the lower cylindrical body 12, and a grout layer configured to inject grout material 38 in the space.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to a hybrid structure, and more particularly to a hybrid structure suitable for constructing a tower structure.

There are various types of tower-like structures such as steel towers and piers, and a monopole type wind power generation tower is known as an example (see, for example, Patent Document 1). In the monopole type, there are restrictions on the diameter of the steel pipes that make up the tower due to land transportation conditions, etc., and there is a limit to the height of the tower hub.

On the other hand, an anchor bolt method is known as a conventional technique for joining a steel pipe to a concrete foundation. The anchor bolt method is generally constructed by burying a plurality of anchor bolts in a concrete-filled foundation (footing) and fastening a steel pipe base plate to the anchor bolts (for example, Patent Document 2). reference).

Japanese Unexamined Patent Publication No. 2012-177326 Japanese Unexamined Patent Publication No. 09-003917

By the way, in the above-mentioned anchor bolt method, since a plurality of anchor bolts are embedded in a concrete foundation, the structure becomes complicated, and the bolt installation accuracy and nut fastening are required, which causes a problem that construction is troublesome. is there. In addition, if the anchor bolt method is applied to a wind power generation tower, the foundation will be filled with concrete, so there is also the problem that equipment necessary for operation management of the wind power generator, such as electric cables and elevators, cannot be accommodated in the lower part of the tower. ..

The technique of the present disclosure has been made in view of the above circumstances, and provides a hybrid structure capable of effectively joining a steel upper cylinder to a concrete lower cylinder with a simple configuration. The purpose is.

In the hybrid structure of the present disclosure, a concrete lower cylinder erected upward and the lower end side thereof are inserted into the upper end side cylinder of the lower cylinder, or the lower cylinder is inserted into the lower end side cylinder thereof. A steel body that is erected upward from the upper end side of the lower cylinder while inserting the upper end side of the body so that the side surface on the lower end side faces the side surface on the upper end side of the lower cylinder with a space. The upper cylinder is provided with a joint portion for joining and supporting the lower end side of the upper cylinder to the upper end side of the lower cylinder, and the joint portion is the space from the side surface of the upper cylinder on the lower end side. A first bearing member projecting inward, a second bearing member projecting into the space from the upper end side side surface of the lower cylinder, and a grout layer formed by filling the space with a grout material. And, characterized by having.

Further, it is preferable that the first bearing member and the second bearing member are provided at least in the intermediate portion in the vertical direction of the joint portion.

Further, the first bearing member and the second bearing member are provided, and the plurality of the first bearing member and the second bearing member are arranged alternately in the vertical direction. preferable.

Further, it is preferable that at least one of the first bearing member and the second bearing member is intermittently provided in the circumferential direction.

Further, a plurality of side plate members are embedded in the side surface of the lower cylinder facing the upper cylinder at predetermined intervals in the circumferential direction, and the second bearing member is provided in each of the plurality of side plate members. The side plate member and the second bearing member may form a jig that is part of the joint.

Further, the lower cylinder is erected upward from the ground, the upper cylinder is formed to have a smaller diameter than the lower cylinder, and the lower end side thereof is the upper end side of the lower cylinder. A wind power generator may be mounted on the upper end of the upper cylinder, which is inserted in the cylinder.

According to the technique of the present disclosure, a steel upper cylinder can be effectively joined to a concrete lower cylinder with a simple structure.

It is a schematic overall block diagram which shows the hybrid structure which concerns on this embodiment. It is a schematic vertical sectional view which shows the lower support body, the upper cylinder body, and the joint part which concerns on this embodiment. It is a schematic cross-sectional view which shows the lower cylinder body, the upper cylinder body, and the joint part which concerns on this embodiment. It is a figure which shows typically the distribution of the bending moment acting on the upper cylinder which concerns on this embodiment, and the contact pressure transmitted to a joint part by a horizontal force. It is a schematic cross-sectional view which shows the lower cylinder body, the upper cylinder body, and the joint part which concerns on another embodiment. It is a schematic cross-sectional view which shows the lower cylinder body, the upper cylinder body, and the joint part which concerns on another embodiment. It is a schematic vertical sectional view which shows the lower support body, the upper cylinder body, and the joint part which concerns on another embodiment. It is a schematic vertical sectional view which shows the lower cylinder body, the upper cylinder body, and the joint part which concerns on another embodiment. It is a schematic vertical sectional view which shows the lower support body, the upper cylinder body, and the joint part which concerns on another embodiment.

Hereinafter, the hybrid structure according to the present embodiment will be described with reference to the accompanying drawings. The same parts have the same reference numerals, and their names and functions are also the same. Therefore, detailed explanations about them will not be repeated.

[overall structure]
FIG. 1 is a schematic overall configuration diagram showing a hybrid structure 1 according to the present embodiment.

As shown in FIG. 1, the hybrid structure 1 is applied to, for example, a wind power generation tower in which a wind power generator 100 is mounted on the top of the tower. The wind power generator 100 includes a plurality of blades 101, a nacelle 102 that houses a generator, a speed reducer, and the like (not shown), and a hub 103 that fixes the base of the blades 101 to the rotor shaft 104.

The hybrid structure 1 includes a lower support 10 constructed of reinforced concrete (RC), prestressed concrete (PC), or the like, and an upper cylinder 20 formed of a steel pipe. The lower support 10 is erected vertically from the ground G, and the upper cylinder 20 is joined to the upper end of the lower support 10 and erected vertically. The nacelle 102 of the wind power generator 100 is fixedly supported at the upper end of the upper cylinder 20.

The protruding height (H1) of the lower support 10 from the ground surface is about 50 m. The protrusion height (H2) of the upper cylinder 20 from the lower support 10 is about 100 m, and the pipe diameter of the upper cylinder 20 is about 4.5 m, which is suitable for land transportation conditions. ..

That is, by making the wind power generation tower a hybrid structure 1 including a concrete lower support 10 and an upper cylinder 20 of a steel pipe joined to the upper end of the lower support 10, the tower portion is mainly made of steel pipe. Compared to the monopole type to be constructed, the height of the hub can be increased by the protruding height (H1) of the lower support 10. As a result, a wind power generation tower with a hub height of more than 100 m can be easily constructed, and further, it becomes possible to adapt to an increase in the size of a wind turbine, and it becomes possible to realize highly efficient wind power generation. ..

The lower end side of the upper cylinder 20 is joined and supported by the lower support 10 via a joint portion 30. Hereinafter, the details of the lower support 10, the upper cylinder 20, and the joint 30 will be described.

[Lower support, upper cylinder, joint]
FIG. 2 is a schematic vertical sectional view showing a lower support 10, an upper cylinder 20, and a joint portion 30 according to the present embodiment.

As shown in FIG. 2, the concrete lower support 10 includes a foundation portion 11 embedded in the ground G and a lower cylinder 12 extending vertically upward from the foundation portion 11 and projecting from the ground G. I have.

The base portion 11 is formed in a substantially truncated cone shape having a diameter larger than that of the lower tubular body 12. The lower cylinder 12 is formed in a substantially cylindrical shape in which the upper end opens, and the inside thereof is hollow from the upper end to the lower end. That is, the lower cylinder 12 is configured to effectively accommodate equipment such as electric cables and elevators necessary for operation management of the wind power generator 100 (see FIG. 1).

The outer diameter of the lower cylinder 12 is preferably about 10 m, and the inner diameter of the lower cylinder 12 is about 4.7 m into which the upper cylinder 20 can be inserted. A plurality of jigs 33 forming a part of the joint portion 30 are embedded in the inner circumference of the lower cylinder 12 on the upper end side. Details of the jig 33 will be described later.

The upper cylinder 20 is a substantially cylindrical steel pipe having a diameter smaller than the inner diameter of the lower cylinder 12. The upper cylinder 20 is provided coaxially with the lower cylinder 12, and the lower end side thereof is inserted and arranged in the upper end side cylinder of the lower cylinder 12. That is, the double tubular joint portion 30 having the lower end side of the upper cylinder 20 and the upper end side of the lower cylinder 12 with the lower cylinder 12 made of concrete on the outside and the upper cylinder 20 made of steel on the inside. Is configured.

In the present embodiment, the amount of the upper cylinder 20 inserted into the lower cylinder 12, in other words, the axial length (height) of the joint portion 30 is preferably about 10 m. The axial length of the joint portion 30 is not limited to about 7 m, and may vary depending on specific dimensions such as the diameter of the lower cylinder 12 and the upper cylinder 20 and the axial length of the upper cylinder 20. It can be appropriately set within a range in which the strength of the joint portion 30 can be sufficiently secured.

A facing space (gap) of about 0.09 to 0.1 m is secured between the outer peripheral surface of the upper cylinder 20 and the inner peripheral surface of the lower cylinder 12. The grout material 38 is filled in the space facing the upper cylinder 20 and the lower cylinder 12. A plurality of inner bearing members 31 (first bearing members of the present disclosure) forming a part of the joint portion 30 are provided on the outer peripheral surface on the lower end side of the upper cylinder 20.

The joint portion 30 includes an inner bearing member 31, a plurality of jigs 33, and a grout layer formed by filling the grout material 38. In the following description, the lower quarter portion obtained by dividing the joint portion 30 into four equal parts in the axial direction (height direction) is referred to as a lower joint portion 30B, and the upper quarter portion is referred to as an upper joint portion. The portion 30U is referred to, and the remaining half portion between the lower joint portion 30B and the upper joint portion 30U is referred to as an intermediate joint portion 30M.

The grout material 38 is, for example, an ultra high strength fiber reinforced concrete (UFC) having excellent compressive strength, tensile strength, fluidity and filling property, and is an upper cylinder 20 and a lower cylinder 12. The space facing the surface is filled from the lower joint portion 30B to the upper joint portion 30U. As the ultra-high strength fiber reinforced concrete, for example, Slim Cleat (registered trademark) can be used. The grout material 38 may be concrete other than ultra-high-strength fiber-reinforced concrete, fiber-reinforced mortar, or the like. When filling the grout material 38, a plate material that closes the lower end opening of the facing space may be provided to prevent the grout material 38 from flowing out, and when the grout material 38 is solidified, the plate material may be removed. ..

The inner bearing member 31 is a convex or convex shear key that protrudes substantially horizontally (diameterally) from the outer peripheral surface of the upper cylinder 20 toward the outside in the radial direction, and has a steel strip or the like as an upper portion. It is formed by joining to the outer peripheral surface of the tubular body 20 by welding or the like in the circumferential direction. A plurality of inner bearing members 31 are preferably provided, and are arranged on the outer peripheral surface of the upper cylinder 20 at predetermined intervals (preferably at equal intervals) in the axial direction. These plurality of inner pressure members 31 are provided on the outer peripheral surface of the upper cylinder 20 corresponding to the intermediate joint portion 30M excluding the lower joint portion 30B and the upper joint portion 30U.

The amount of protrusion of the inner bearing member 31 from the upper cylinder 20 is about 0.03 m, which is less than half of the facing space, and the width (axial length) of the inner bearing member 31 is about 0.05 m. ing. The inner bearing member 31 may be provided intermittently on the outer peripheral surface of the upper cylinder 20 at predetermined intervals in the circumferential direction. If the inner bearing member 31 is provided intermittently, the fluidity of the grout material 38 can be effectively ensured when the grout material 38 is filled.

The plurality of jigs 33 include a side plate member 34 embedded in the lower cylinder 12 and a plurality of outer bearing members 35 (second bearing members of the present disclosure) protruding from the side plate members 34.

The side plate member 34 is formed of, for example, a steel arc plate member or the like. A plurality of stud gibber 36s embedded in the concrete lower cylinder 12 are provided on the outer peripheral surface of the arc of the side plate member 34. The side plate member 34 is embedded in the lower cylinder 12 so that its arc inner peripheral surface is flush with the inner peripheral surface of the lower cylinder 12.

The outer bearing member 35 is a convex or convex shear key that protrudes substantially horizontally in the radial direction from the inner peripheral surface of the arc of the side plate member 34, and is made of a steel strip or the like of the side plate member 34. It is formed by joining to the inner peripheral surface of an arc by welding or the like in the circumferential direction. A plurality of outer bearing members 35 are preferably provided, and are arranged at predetermined intervals (preferably equal intervals) in the axial direction on the inner peripheral surface of the arc of the side plate member 34. The amount of protrusion of the outer bearing member 35 from the side plate member 34 is about 0.03 m, which is less than half of the facing space, and the width (axial length) of the outer bearing member 35 is about 0.05 m. There is.

The side plate member 34 and the outer bearing member 35 are provided on the inner peripheral surface of the lower cylinder 12 corresponding to the intermediate joint portion 30B excluding the lower joint portion 30B and the upper joint portion 30U. .. The outer bearing member 35 is provided so as to be offset by a predetermined amount in the axial direction with respect to the inner bearing member 31, and a plurality of outer bearing members 35 and the inner bearing member 31 are axially provided at the intermediate joint portion 30M. They are arranged so as to be staggered. The number of outer bearing members 35 is preferably one more than that of the inner bearing member 31. The present disclosure does not exclude that the side plate member 34 and the outer bearing member 35 are provided on either one or both of the lower joint portion 30B and the upper joint portion 30U.

That is, by arranging the inner bearing member 31 so as to be sandwiched vertically by the outer bearing member 35, each bearing member 31 can be placed on the grout layer between the inner bearing member 31 and the outer bearing member 35. Diagonal struts connecting the corners of 35 are formed. This makes it possible to effectively counter the axial force acting on the joint portion 30. Further, since the inner bearing member 31 and the outer bearing member 35 do not face each other in the radial direction, it is possible to secure a sufficient gap for flowing the grout material 38 between the bearing members 31 and 35. ..

FIG. 3 is a schematic cross-sectional view showing the lower cylinder body 12, the upper cylinder body 20, and the joint portion 30 according to the present embodiment.

As shown in FIG. 3, a plurality of jigs 33 (4 in the illustrated example) are provided along the inner peripheral surface of the lower cylinder 12, and the arc inner peripheral surface of the side plate member 34 and the lower cylinder 12 A circumferential surface surrounding the outer peripheral surface of the upper cylinder 20 is formed by the inner peripheral surface of the upper cylinder 20. Specifically, the plurality of jigs 33 are arranged at predetermined intervals (preferably at equal intervals) in the circumferential direction along the inner peripheral surface of the lower cylinder 12, and the arc inner peripheral surface of the side plate member 34. Is embedded in the lower cylinder 12 so that is flush with the inner peripheral surface of the lower cylinder 12. That is, by arranging the plurality of jigs 33 at predetermined intervals in the circumferential direction, a gap 37 is secured between the outer bearing members 35 adjacent to each other in the circumferential direction.

In this way, the outer bearing member 35 is provided intermittently in the circumferential direction to secure a gap 37 for flowing the grout material 38 between the adjacent outer bearing members 35, whereby the upper cylinder 20 and the lower cylinder 20 and the lower cylinder are secured. The grout material 38 can be easily filled in the space facing the twelve. Further, by improving the fluidity of the grout material 38, the filling time of the grout material 38 can be surely shortened, and the local unfilling of the grout material 38 can be effectively prevented. The number of jigs 33 is not limited to 4 in the illustrated example, and may be 2, 3, or 5 or more.

Next, based on FIG. 4, the action and effect of the joint portion 30 of the hybrid structure 1 according to the present embodiment will be described.

FIG. 4 is a diagram schematically showing the distribution of the bending moment M acting on the upper cylinder 20 and the contact pressure P transmitted to the joint portion 30 by the horizontal force Y.

The distribution of the contact pressure P increases from the vertical center position C side of the joint portion 30 toward the upper end side, and increases from the vertical center position C side of the joint portion 30 toward the lower end side. Further, since the difference in rigidity from the upper cylinder 20 greatly changes on the upper end side where the lower cylinder 12 opens, the bending moment M and the horizontal force Y acting on the upper cylinder 20 are easily received, and the joint portion 30 A local increase in contact pressure P (stress concentration) occurs on the upper end side of the. On the other hand, since the rigidity of the lower end side of the joint portion 30 is ensured by the concrete lower cylinder 12 surrounding the outer end side thereof, the local increase in the contact pressure P is suppressed. Further, the axial force Z in the direction of pushing the upper cylinder 20 downward and the direction of pulling it upward is transmitted to the joint portion 30 that joins and supports the upper cylinder 20 to the lower cylinder 12.

In the present embodiment, the inner bearing member 31 and the outer bearing member 35 that bear the axial force Z are provided in the upper joint portion 30U and the intermediate joint portion 30M in which the distribution of the contact pressure P is smaller than that of the lower joint portion 30B. Has been done. That is, the grout layer of the intermediate joint portion M in which the distribution of the contact pressure P is relatively small is configured so that the diagonal struts S connecting the corner portions of the bearing members 31 and 35 can be formed. As a result, struts S are formed in a stable grout layer that is less affected by the contact pressure P, and can effectively counter the axial force Z, and the axial joint strength between the upper cylinder 20 and the lower cylinder 12 becomes stronger. Can be definitely improved.

Further, by arranging the inner bearing members 31 and the outer bearing members 35 so as to be staggered in the axial direction, the intermediate joint portion M has a structure in which the bearing members 31 and 35 face each other in the radial direction. It becomes possible to prevent the formed grout layer from becoming thin, and it becomes possible to effectively prevent the occurrence and destruction of cracks in the grout layer.

Further, the upper joint portion 30U and the lower joint portion 30B having a large distribution of the contact pressure P are filled with the grout material 38 without providing the bearing members 31 and 35 that bear the axial force Z, thereby forming the upper joint portion 30U and the lower joint portion 30B. The joint portion 30U and the lower joint portion 30B are configured to form a thick grout layer in the radial direction. As a result, the horizontal force Y and the bending moment M acting on the upper cylinder 20 can be effectively countered by the thick grout layer, and the grout layer at the relevant portion is destroyed or the seat of the upper cylinder 20 is seated. It is possible to suppress bending deformation and the like.

Summarizing the present embodiment described in detail above, the wind power generation tower is joined to the concrete lower cylinder 12 protruding from the ground G and the upper portion of the steel pipe erected above the upper end side of the lower cylinder 12. By adopting the hybrid structure 1 having the cylinder body 20, the hub height of the tower can be increased by the protruding height of the lower cylinder body 12 as compared with the case where the wind power generation tower is constructed in a monopole format. ing.

Specifically, for the upper cylinder 20, a steel pipe having a pipe axial length of about 100 m and a pipe diameter of about 4.5 m suitable for land transportation conditions is used, and the steel pipe is about 50 m above the ground G. By joining to the concrete lower cylinder 12 protruding from the ridge, it becomes possible to easily construct a wind power generation tower having a hub height of more than 100 m. As a result, compared to the monopole type in which the entire tower is constructed of steel pipes, it becomes possible to effectively adapt to the increase in size of the wind turbine, and it becomes possible to realize highly efficient wind power generation.

Further, the concrete lower cylinder 12 has a cylindrical shape, and the inside of the tower including the joint portion 30 and the upper cylinder 20 is hollow from the lower end side to the upper end side, so that an electric cable, an elevator, etc. It is also possible to effectively accommodate the equipment necessary for the operation management of the wind power generator 100 inside the tower.

Further, it is not necessary to fill the axial side of the joint portion 30 and its vicinity with concrete, and the concrete lower cylinder 12 has a cylindrical shape, so that the amount of concrete used can be effectively reduced. It is also possible to shorten the construction period while surely reducing the construction cost.

[Other]
The present disclosure is not limited to the above-described embodiment, and can be appropriately modified and implemented without departing from the spirit of the present disclosure.

For example, the plurality of jigs 33 have been described as being arranged at predetermined intervals in the circumferential direction along the inner peripheral surface of the lower cylinder 12, but as shown in FIG. 5, the plurality of jigs 33 are arranged at lower portions. It may be provided in a circumferential direction along the inner peripheral surface of the tubular body 12. Alternatively, as shown in FIG. 6, the side plate member 34 may be formed into a cylindrical shape to form one jig 33.

Further, as shown in FIG. 7, the frictional resistance between the upper cylinder 20 and the grout layer is reduced over a predetermined range from the upper end side of the outer peripheral surface corresponding to the upper joint portion 30U of the upper cylinder 20. Friction reduction treatment F (for example, application of low friction paint, attachment of low friction material, etc.) may be applied. In this way, if the frictional resistance of the upper joint 30U where the contact pressure P locally increases is made lower than that of the intermediate joint 30M, the lower joint 30B, etc., a large horizontal force and bending moment are applied to the upper cylinder 20. The frictional force acting between the upper cylinder 20 and the upper joint 30U, and the stress of the grout layer and the concrete lower cylinder 12 can be effectively reduced when It is possible to effectively suppress buckling deformation of the tubular body 20 and the like. The friction reduction process F is performed not only on the outer peripheral surface of the upper cylinder 20 in the illustrated example, but also on the inner peripheral surface of the lower cylinder 12, the outer peripheral surface of the upper cylinder 20, and the inner surface of the lower cylinder 12. It can also be applied to both peripheral surfaces.

Further, although the concrete lower cylinder 12 has been described as protruding from the ground G, as shown in FIG. 8, the lower cylinder 12 is embedded in the deep part of the ground G and the upper cylinder 20 is the ground G. It may be configured to protrude from.

Further, as shown in FIG. 9, the lower cylinder 12 is formed to have a smaller diameter than the upper cylinder 20, and the upper end side of the lower cylinder 12 is inserted into the lower end cylinder of the upper cylinder 20. May be good. In this case, the first bearing member 31 is provided as the outer bearing member on the inner peripheral surface of the upper cylinder 20, the jig 33 is embedded in the outer peripheral surface of the lower cylinder 12, and the second bearing member 35 is provided. It may be provided as an inner bearing member on the outer peripheral surface of the arc of the side plate member 34.

Further, the shape of the upper cylinder 20 and the lower cylinder 12 is not limited to the cylindrical shape shown in the illustrated example, and may be another cylindrical shape such as a rectangular tubular shape. Further, the application of the present disclosure is not limited to the construction of a wind power generation tower, and can be widely applied to the construction of other tower-like structures such as steel towers and piers.

10 Lower support 11 Base 12 Lower cylinder 20 Upper cylinder 30 Joint 30U Upper joint 30B Lower joint 30M Intermediate joint 31 Inner bearing member (first bearing member)
33 Jig 34 Side plate member 35 Outer bearing member (second bearing member)
38 Grout 100 Wind Turbine 101 Blade 102 Nacelle 103 Hub

Claims (6)

The concrete lower cylinder that stands upward and
The lower end side is inserted into the upper end side cylinder of the lower cylinder, or the upper end side of the lower cylinder is inserted into the lower end side cylinder, and the lower end side surface is regarded as the upper end side side surface of the lower cylinder body. A steel upper cylinder that is erected upward from the upper end side of the lower cylinder while facing each other across a space.
A joint portion for joining and supporting the lower end side of the upper cylinder to the upper end side of the lower cylinder is provided.
The joint
A first bearing member protruding into the space from the side surface on the lower end side of the upper cylinder, and
A second bearing member projecting into the space from the side surface of the lower cylinder on the upper end side,
A hybrid structure characterized by having a grout layer formed by filling the space with a grout material. The hybrid structure according to claim 1, wherein the first bearing member and the second bearing member are provided at least in an intermediate portion in the vertical direction of the joint portion. Claim 1 or claim 1, which has a plurality of the first bearing member and the second bearing member, and the plurality of the first bearing member and the second bearing member are arranged alternately in the vertical direction. 2. The hybrid structure according to 2. The hybrid structure according to any one of claims 1 to 3, wherein at least one of the first bearing member and the second bearing member is intermittently provided in the circumferential direction. A plurality of side plate members are embedded in the side surface of the lower cylinder facing the upper cylinder at predetermined intervals in the circumferential direction, and the second bearing member is provided in each of the plurality of side plate members. The hybrid structure according to any one of claims 1 to 4, wherein the side plate member and the second bearing member constitute a jig forming a part of the joint portion. The lower cylinder is erected upward from the ground, the upper cylinder is formed to have a smaller diameter than the lower cylinder, and the lower end side thereof is inside the upper end side cylinder of the lower cylinder. The hybrid structure according to any one of claims 1 to 5, wherein the wind power generator is mounted on the upper end portion of the upper cylinder.

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