JP2022018840A - Steel tower foundation structure and construction method of the same - Google Patents

Abstract

To provide a steel tower foundation structure which shortens a construction time required for construction of a foundation part of a steel tower while securing a weight of the foundation part of the steel tower, and facilitates transportation of a material constituting the foundation part of the steel tower, and a construction method of the same.SOLUTION: A foundation part 22 of a steel tower includes a plurality of upper floor board blocks 50 and lower floor board blocks 52, which are made of precast concrete. The upper floor board blocks 50 include first upper vertical reinforcements 60A arranged on an inner peripheral side of spiral reinforcements 30, and the lower floor board blocks 52 include first lower vertical reinforcements 70A arranged on the inner peripheral side of the spiral reinforcements 30. A plurality of inner reinforcements 78B are arranged on the inner peripheral side of the spiral reinforcements 30. The first upper vertical reinforcements 60A, the first lower vertical reinforcements 70A and the inner reinforcements 78B are embedded in a concrete-made interposition part.SELECTED DRAWING: Figure 1

Description

The present invention relates to a steel tower foundation structure and a method for constructing the same.

The following Patent Document 1 describes an invention relating to a steel tower foundation structure. In this tower foundation structure, an inner piece made of precast concrete is provided integrally with the leg members that form a part of the steel leg portion of the tower. The inner piece is built into an inverted T-shaped foundation provided with a floor plate.

Japanese Unexamined Patent Publication No. 2020-94457 (FIG. 8)

By the way, it is conceivable that a pull-out load caused by an electric wire or the like suspended on the tower acts on the tower. Then, in supporting this pull-out load, it is preferable that the weight of the floor plate connected to the leg member is large. Further, from the viewpoint of shortening the construction time, it is preferable to use precast concrete for the floor board.

However, when the steel tower is constructed in a mountainous area or the like, the weight of the material that can be transported is limited, so that the weight of the precast concrete that can be used for the floorboard is also limited.

In consideration of the above facts, the present invention shortens the construction time required for constructing the foundation of the tower while securing the weight of the foundation of the tower, and facilitates the transportation of the materials constituting the foundation of the tower. It is an object of the present invention to provide a steel tower foundation structure and a method for constructing the same.

The steel tower foundation structure according to the first aspect is provided integrally with a leg material forming a part of a steel frame leg portion of the steel tower and a lower end portion of the steel tower in the height direction of the leg material, and is flat. An inner piece made of precast concrete arranged on a simple installation surface and an annular shape when viewed from the height direction of the steel tower, and the outer peripheral side of the inner piece in a state where the axial direction is the height direction. A part of the floor plate arranged on the outer peripheral side of the spiral muscle and the spiral muscle arranged in the concrete muscle, and along the circumferential direction of the spiral muscle on the outer peripheral side of the upper portion in the height direction of the spiral muscle. A plurality of precast concrete upper floorboard blocks arranged in contact with each other and a part of the floorboard are formed, and the circumference of the spiral muscle is on the outer peripheral side of the lower portion in the height direction of the spiral muscle. A plurality of precast concrete lower floorboard blocks arranged in a state of being in contact with each other along the direction, and a part thereof embedded in the upper floorboard block, arranged on the inner peripheral side of the spiral bar, and the height. A plurality of upper reinforcing bars having a first upper vertical bar extending from the upper side in the vertical direction to the lower side in the height direction, and a part of the lower floor board block is embedded in the inner peripheral side of the spiral bar. A lower reinforcing bar provided with a first lower vertical bar that is arranged and extends from the lower side in the height direction to the upper side in the height direction, and a circumferential direction of the spiral bar on the inner peripheral side of the spiral bar. A plurality of inner reinforcing bars arranged along the above and spanned between a first plane orthogonal to the first upper vertical bar and a second plane orthogonal to the first lower vertical bar, and the inner piece. It is provided between the floor plate and the inner piece and the floor plate in close contact with the floor plate, and the spiral bar, the first upper vertical bar, the first lower vertical bar and the inner reinforcing bar are embedded. It has an intervening part made of concrete.

According to the steel tower foundation structure of the structure according to the first aspect, the inner piece is below the height direction (hereinafter, simply referred to as the height direction) of the steel tower in the leg material forming a part of the steel frame leg portion of the steel frame. It is provided integrally with the side end. Since this inner piece is made of precast concrete and the inner piece is arranged on a flat installation surface, the leg material can be positioned by arranging the inner piece on the installation surface. ..

Further, on the outer peripheral side of the inner piece, a spiral streak having an annular shape when viewed from the height direction is arranged in a state where the axial direction is the height direction. A floor plate is arranged on the outer peripheral side of the spiral muscle, and a concrete intervening portion is interposed between the inner piece and the floor plate, and the intervening portion is placed on the inner piece and the floor plate. It is in close contact. Therefore, in this embodiment, even if the pull-out load caused by the electric wire or the like suspended on the steel tower acts on the leg member, the pull-out load can be supported by the weight of the floor plate. In addition, the shear load acting on the leg member can be supported by the spiral muscle.

By the way, in supporting the pull-out load acting on the leg member, it is preferable that the weight of the floor plate connected to the leg member is large. Further, from the viewpoint of shortening the construction time, it is preferable to use precast concrete for the floor board. On the other hand, when a steel tower is constructed in a mountainous area or the like, the weight of the material that can be transported is limited, so that the weight of precast concrete that can be used for the floorboard is also limited.

Here, in this embodiment, a plurality of upper floor board blocks and lower floor board blocks made of precast concrete are included. Specifically, the plurality of upper floor plate blocks are arranged on the outer peripheral side of the upper portion of the spiral muscle in the height direction in a state where the upper floor plate blocks are in contact with each other along the circumferential direction of the spiral muscle. On the other hand, the plurality of lower floor plate blocks are arranged on the outer peripheral side of the lower portion in the height direction of the spiral muscle in a state where the lower floor plate blocks are in contact with each other along the circumferential direction of the spiral muscle. ..

Therefore, in this embodiment, the members constituting the floor plate can be divided and transported, and as a result, the weight of the floor plate can be secured even when the steel tower is constructed in a mountainous area or the like.

By the way, when only the intervening portion transmits the load from the leg material side to the upper floor board block and the lower floor board block, the magnitude of the load acting on these between the upper floor board block and the lower floor board block. It is conceivable that there will be a bias.

Here, in the present embodiment, the upper floor board block is provided with a plurality of upper reinforcing bars partially embedded in the upper floor board block, and the upper reinforcing bars are arranged on the inner peripheral side of the spiral bar. It also has a first upper vertical streak extending from the upper side in the height direction to the lower side in the height direction. On the other hand, the lower floor plate block is provided with a lower reinforcing bar partially embedded in the lower floor board block, and the lower reinforcing bar is arranged on the inner peripheral side of the spiral bar and is high. It is provided with a first lower vertical streak extending from the lower side in the vertical direction to the upper side in the height direction.

Further, on the inner peripheral side of the spiral muscle, a plurality of inner reinforcing bars are arranged along the circumferential direction of the spiral muscle, and the inner reinforcing bars are the first plane and the first plane orthogonal to the first upper vertical bar. It is laid between the lower vertical streak and the second plane orthogonal to it. The first upper vertical bar, the first lower vertical bar, and the inner reinforcing bar are in a state of being embedded in the intervening portion.

Therefore, the first upper vertical bar and the first lower vertical bar are connected in the height direction via the inner reinforcing bar and the intervening portion, and the upper floor board block and the lower floor board block have the first The load from the leg member side is similarly transmitted via the upper vertical bar, the first lower vertical bar, and the inner reinforcing bar. As a result, in this embodiment, the load from the leg member side can be supported by the entire floor plate.

The steel tower foundation structure according to the second aspect has the concrete on the surface of the inner piece on the spiral bar side and the inner peripheral surface of the floor plate on the spiral bar side in the steel tower foundation structure according to the first aspect. A filled inner recess is provided.

According to the steel tower foundation structure according to the second aspect, an inner recess is provided on the surface of the inner piece on the spiral muscle side and the inner peripheral surface of the floor plate on the spiral muscle side, and the inner recess is interposed. The concrete that forms part of the part is filled. That is, the intervening portion is provided with a protrusion protruding toward the inner piece side and a protruding portion protruding toward the floor plate side.

Therefore, the shearing force acting on the intervening portion when the inner piece and the floor plate try to move relative to each other is supported by these protrusions provided on the intervening portion, and as a result, the floor plate is supported by the intervening portion. The load due to its own weight can be easily transmitted to the inner piece side.

The iron tower foundation structure according to the third aspect is the surface of the upper floor plate block on the lower floor plate block side and the upper floor plate of the lower floor plate block in the iron tower foundation structure according to the first aspect or the second aspect. A protrusion protruding from the other is formed on one of the surfaces on the block side, and an engaged portion with which the protrusion can be engaged is formed on the other, and the protrusion is covered. By engaging with the engaging portion, it is possible to limit the relative displacement of the upper floor plate block and the lower floor plate block in the direction orthogonal to the height direction.

According to the steel tower foundation structure according to the third aspect, one of the surface of the upper floor plate block on the lower floor plate block side and the surface of the lower floor plate block on the upper floor plate block side has protrusions protruding from the other. A portion is formed, and an engaged portion with which the protrusion can be engaged is formed on the other side. Then, by engaging the protrusion with the engaged portion, the relative displacement of the upper floor plate block and the lower floor plate block in the direction orthogonal to the height direction is limited.

By the way, it is conceivable that a moment caused by the weight of the tower and a reaction force from the ground against the weight of the tower and a moment caused by an external force received by the tower are generated on the floor plate. When the moment is generated in the floor plate in a state where the relative displacement in the direction orthogonal to the height direction between the upper floor plate block and the lower floor plate block is not restricted, the moment is generated between the upper floor plate block and the lower floor plate block. It is conceivable that slippage will occur and it will be difficult for the entire floorboard to support the moment.

Here, in this embodiment, as described above, since the relative displacement of the upper floor plate block and the lower floor plate block in the direction orthogonal to the height direction is restricted by the protrusion and the engaged portion, the floor plate is described above. Even if a moment is generated, the moment can be supported by the entire floor plate.

The iron tower foundation structure according to the fourth aspect is arranged between the upper floor plate block and the lower floor plate block in the iron tower foundation structure according to the first aspect or the second aspect, and is one of the floor plates. A precast concrete intermediate floor board block is further provided on the outer peripheral side of the spiral bar in a state of being in contact with each other along the circumferential direction of the spiral bar, and the middle of the upper floor board block is further provided. A first protrusion projecting with respect to the other is formed on one of the surface on the floor plate block side and the surface on the upper floor plate block side of the intermediate floor plate block, and the first protrusion is formed on the other. An engageable first engaged portion is formed, and the first protrusion is engaged with the first engaged portion so that the upper floor plate block and the intermediate floor plate block are engaged with each other in the height direction. Relative displacement in the orthogonal direction can be restricted, and one of the surface of the intermediate floor plate block on the lower floor plate block side and the surface of the lower floor plate block on the intermediate floor plate block side is relative to the other. A protruding second protrusion is formed, and a second engaged portion with which the second protrusion can be engaged is formed on the other side, and the second protrusion is the second engaged portion. It is possible to limit the relative displacement of the intermediate floor plate block and the lower floor plate block in the direction orthogonal to the height direction by being engaged with.

According to the steel tower foundation structure according to the fourth aspect, the intermediate floor board block made of precast concrete forming a part of the floor board between the upper floor board block and the lower floor board block is provided on the outer peripheral side of the spiral bar. They are arranged so as to be in contact with each other along the circumferential direction of the concrete.

Further, on one of the surface of the upper floor plate block on the intermediate floor plate block side and the surface of the intermediate floor plate block on the upper floor plate block side, a first protrusion projecting with respect to the other is formed, and the other surface is formed. , A first engaged portion is formed to which the first protrusion can be engaged. Then, by engaging the first protrusion with the first engaged portion, the relative displacement of the upper floor plate block and the intermediate floor plate block in the direction orthogonal to the height direction is limited.

Further, on one of the surface of the lower floor plate block on the lower floor plate block side and the surface of the lower floor plate block on the intermediate floor plate block side, a second protrusion protruding from the other is formed, and the other Is formed with a second engaged portion to which the second protrusion can be engaged. Then, by engaging the second protrusion with the second engaged portion, the relative displacement of the intermediate floor plate block and the lower floor plate block in the direction orthogonal to the height direction is limited.

Therefore, in this embodiment, while increasing the weight of the floor plate, the moment generated in the floor plate, that is, the weight of the tower, the moment caused by the reaction force from the ground against the weight, and the moment caused by the external force received by the tower are applied to the entire floor plate. Can be supported by.

The steel tower foundation structure according to the fifth aspect is the steel tower foundation structure according to any one of the first to fourth aspects, and the spiral bar is on the outer peripheral surface of the floor plate opposite to the spiral bar. There is an outer recess that is recessed on the side.

According to the steel tower foundation structure according to the fifth aspect, an outer concave portion recessed on the spiral bar side is provided on the outer peripheral surface of the floor plate on the opposite side to the spiral bar. Therefore, when the floor board is buried in the soil, the mortar and soil around the floor board are filled in the outer recesses. As a result, in this embodiment, the mortar or soil filled in the outer recess can function as a resistance to the pull-out load acting on the leg material.

The steel tower foundation structure according to the sixth aspect is the steel tower foundation structure according to any one of the first to fifth aspects, wherein the upper reinforcing bar is continuous with the first upper vertical bar and the first one. 1 The upper horizontal bar extending radially outward from the upper vertical bar is provided, and the lower reinforcing bar is continuous with the first lower vertical bar and the spiral from the first lower vertical bar. A lower lateral bar extending radially outward of the muscle is provided, and an upper end bar connecting the upper lateral bar adjacent to the circumferential direction of the spiral muscle in the circumferential direction and the lower lateral bar adjacent to the circumferential direction are provided. It also has a lower end streak that connects in the circumferential direction.

According to the steel tower foundation structure according to the sixth aspect, the upper reinforcing bar provided in the upper floor plate block has an upper horizontal bar continuous with the first upper vertical bar, and the upper horizontal bar is the first upper vertical bar. It extends radially outward from the muscle. Then, the upper lateral muscles adjacent to the spiral muscles in the circumferential direction are connected in the circumferential direction by the upper end muscles. Therefore, in this embodiment, the bearing capacity of the ground against the pulling load acting on the leg member can be transmitted to the entire upper floor board block.

Further, the lower reinforcing bar provided in the lower floor plate block is provided with a lower horizontal bar continuous with the first lower vertical bar, and the lower horizontal bar is a spiral bar from the first lower vertical bar. It extends outward in the radial direction. Then, the lower horizontal muscles adjacent to the spiral muscles in the circumferential direction are connected in the circumferential direction by the lower end muscles. Therefore, in this embodiment, the bearing capacity of the ground against the pulling load acting on the leg member can be transmitted to the entire lower floor board block.

The steel tower foundation structure according to the seventh aspect is the steel tower foundation structure according to the sixth aspect, in which the upper end bar provided on one of the upper floor plate blocks and the other upper end bar at the boundary between the upper floor plate blocks and the other. It further has a circumferential joint portion for connecting the upper end bar provided on the upper floor plate block in the circumferential direction.

According to the steel tower foundation structure according to the seventh aspect, at the boundary between the upper floor board blocks, the upper end bar provided on one upper floor board block and the upper end bar provided on the other upper floor board block are peripheral. It is connected in the circumferential direction of the spiral bar by the directional joint. Therefore, in this embodiment, the pull-out load acting on the leg member can be distributed and supported on the upper part of the floor plate.

The steel tower foundation structure according to the eighth aspect is the steel tower foundation structure according to the sixth or seventh aspect, in which the upper reinforcing bar is continuous with the upper horizontal bar and is downward from the upper horizontal bar in the height direction. The lower end in the height direction is provided with a second upper vertical bar exposed from the floor plate, and the lower reinforcing bar is continuous with the lower horizontal bar and said from the lower horizontal bar. A second lower vertical bar extending upward in the height direction and having an end portion on the upper side in the height direction exposed from the floor plate is provided, and the second upper vertical bar and the second lower vertical bar are provided. It further has a height direction joint portion connected in the height direction.

According to the steel tower foundation structure according to the eighth aspect, the upper reinforcing bar provided in the upper floor plate block has a second upper vertical bar continuous with the upper horizontal bar, and the second upper vertical bar is the upper side. It extends downward from the horizontal streaks in the height direction, and the lower end in the height direction is exposed from the floor plate.

Further, the lower reinforcing bar provided on the lower floor plate block has a second lower vertical bar continuous with the lower horizontal bar, and the second lower vertical bar is in the height direction from the lower horizontal bar. It extends upward and the upper end in the height direction is exposed from the floorboard. The second upper vertical bar and the second lower vertical bar are connected in the height direction by the height direction joint portion. Therefore, in this embodiment, the pulling load acting on the leg member can be distributed and supported in the upper part and the lower part of the floor plate.

The steel tower foundation structure according to the ninth aspect is arranged on the upper side of the floor plate in the height direction in the steel tower foundation structure according to any one of the first to eighth aspects, and from the height direction. As seen, it constitutes a part of the pillar body surrounding the leg member, and further has a pillar body component made of precast concrete that connects the inner reinforcing bars to each other in the circumferential direction of the spiral bar.

According to the steel tower foundation structure according to the ninth aspect, by arranging the precast concrete pillar body component on the upper side in the height direction of the floor plate, one of the pillar bodies surrounding the leg material of the steel tower when viewed from the height direction. It can form a part. Further, the inner reinforcing bars are connected to each other in the circumferential direction by the prism constituents, and the inner reinforcing bars can be positioned by the prism constituents. Therefore, in this embodiment, the construction time can be shortened as compared with the configuration in which ready-mixed concrete is placed to construct a pillar body.

In the steel tower foundation structure according to the tenth aspect, in the steel tower foundation structure according to the ninth aspect, the inner peripheral surface of the floor plate on the spiral bar side has a center on the leg member side when viewed from the height direction. It is formed along the circumference, and the inner circumference of the pillar constituent portion has a circumferential shape surrounding the inner peripheral surface when viewed from the height direction.

According to the steel tower foundation structure according to the tenth aspect, the inner peripheral surface of the floor plate on the spiral muscle side is formed along the circumference having a center on the leg member side when viewed from the height direction. That is, the floor plate is in a state where a circular penetrating portion is formed when viewed from the height direction. On the other hand, the inner circumference of the pillar constituent portion has a circumferential shape surrounding the inner peripheral surface of the floor plate when viewed from the height direction. Therefore, when the prism component is aligned with respect to the floor plate, it is possible to prevent the prism component from falling into the penetrating portion of the floor plate.

In the method for constructing the steel tower foundation structure according to the eleventh aspect, a precast concrete inner piece provided integrally with one end of the leg material forming a part of the steel frame leg portion of the steel tower is placed on a flat installation surface. Then, a plurality of precast concrete lower floorboard blocks constituting a part of the floorboard are arranged in a state of being in contact with each other so as to surround the inner piece when viewed from the height direction of the steel tower, and the axial direction is the height. A first lower vertical direction extending from the lower side in the height direction to the upper side in the height direction on the inner piece side of the lower floor board block while providing a spiral streak in the vertical direction on the lower floor board block. The upper floorboard block made of precast concrete, which is arranged so that the streaks are located on the inner peripheral side of the spiral streaks and the inner piece is surrounded by the spiral streaks and constitutes a part of the floorboard, is in the height direction. The first upper vertical bar provided on the upper floor plate block is arranged so as to be located on the inner peripheral side of the spiral bar in a state where a plurality of the inner pieces are in contact with each other so as to surround the inner piece. A plurality of inner reinforcing bars extending in the radial direction are laid between a first plane orthogonal to the first upper vertical bar and a second plane orthogonal to the first lower vertical bar, and the spiral. Arranged at intervals along the circumferential direction of the spiral bar on the inner peripheral side of the bar, ready-mixed concrete is placed between the inner piece and the floor plate.

According to the method for constructing the steel tower foundation structure according to the eleventh aspect, the inner piece made of precast concrete provided integrally with one end of the leg material forming a part of the steel frame leg portion of the steel tower is placed on a flat installation surface. Place it.

Next, a plurality of precast concrete lower floorboard blocks constituting a part of the floorboard are arranged in a state of being in contact with each other so as to surround the inner piece when viewed from the height direction. Further, the lower floor plate block is provided with a first lower vertical streak extending from the lower side in the height direction to the upper side in the height direction on the inner piece side of the lower floor plate block. Then, the spiral muscle having the height direction in the axial direction is arranged so that the first lower vertical muscle is located on the inner peripheral side of the spiral muscle and the inner piece is surrounded by the spiral muscle.

Next, a plurality of precast concrete upper floorboard blocks constituting a part of the floorboard are provided in a state of being in contact with each other so as to surround the inner piece when viewed from the height direction, and are provided on the upper floorboard block. Arrange so that the upper vertical streak is located on the inner peripheral side of the spiral streak.

Next, a plurality of inner reinforcing bars extending in the height direction are laid between the first plane orthogonal to the first upper vertical bar and the second plane orthogonal to the first lower vertical bar. And on the inner peripheral side of the spiral muscle, they are arranged at intervals along the circumferential direction of the spiral muscle.

Then, ready-mixed concrete is placed between the inner piece and the floor plate, and a spiral bar, a first upper vertical bar, a first lower vertical bar, and an inner reinforcing bar are embedded between the inner piece and the floor board. Form a part.

Therefore, in this embodiment, the members constituting the floor plate can be divided and transported, and as a result, the weight of the floor plate can be secured even when the steel tower is constructed in a mountainous area or the like. Further, in this embodiment, the first upper vertical bar and the first lower vertical bar are connected in the height direction via the inner reinforcing bar and the intervening portion, and the upper floor board block and the lower floor board block are connected to each other. , The load from the leg member side is similarly transmitted via the first upper vertical bar, the first lower vertical bar and the inner reinforcing bar. As a result, in this embodiment, the load from the leg member side can be supported by the entire floor plate.

As described above, the steel tower foundation structure and the method for constructing the steel tower foundation according to the present invention shorten the construction time required for constructing the steel tower foundation while securing the weight of the steel tower foundation portion, and further constitute the steel tower foundation. It has an excellent effect that the transportation of the material to be carried out can be facilitated.

It is sectional drawing which shows the structure of the steel tower foundation structure which concerns on 1st Embodiment. It is a perspective view which shows the structure of the inner piece of the steel tower foundation structure which concerns on 1st Embodiment. It is a perspective view which shows the structure of the leg member of the steel tower foundation structure which concerns on 1st Embodiment. It is a perspective view which shows the structure of the upper floor board block of the steel tower foundation structure which concerns on 1st Embodiment. It is a perspective view which shows the structure of the lower floor board block of the steel tower foundation structure which concerns on 1st Embodiment. It is a perspective view which shows the structure of the spiral bar of the steel tower foundation structure which concerns on 1st Embodiment. It is a perspective view which shows the structure of the prism structure piece of the steel tower foundation structure which concerns on 1st Embodiment. It is a perspective view which shows the structure of the steel tower foundation structure which concerns on 1st Embodiment. It is a side view which shows typically the structure of the steel tower to which the steel tower foundation structure which concerns on 1st Embodiment is applied. It is a perspective view which shows the structure of the steel tower foundation structure which concerns on 2nd Embodiment. It is a perspective view which shows the structure of the upper floor board block of the steel tower foundation structure which concerns on 2nd Embodiment. It is a perspective view which shows the structure of the lower floor board block of the steel tower foundation structure which concerns on 2nd Embodiment. It is sectional drawing which shows the structure of the steel tower foundation structure which concerns on 3rd Embodiment.

Hereinafter, the first embodiment of the steel tower foundation structure and the construction method thereof according to the present invention will be described with reference to FIGS. 1 to 9.

As shown in FIG. 9, the "steel tower 10" to which the steel tower foundation structure according to the present embodiment is applied is constructed in a mountainous area, and has a plurality of main pillar members 12, a plurality of horizontal members 14, and a plurality of members. It is composed of the diagonal member 16 and a plurality of auxiliary members 18 for the main column member bridged between the main column member 12 and the diagonal member 16, and includes four “steel frame legs 20”. A foundation portion 22 is provided for each steel frame leg portion 20. In the following, unless otherwise specified, the height direction of the tower 10 is simply referred to as the height direction.

As shown in FIGS. 1 and 8, the foundation portion 22 supports the “leg member 24” constituting a part of the steel frame leg portion 20 with respect to the ground 26, and also has the “inner piece 28” and the “spiral muscle”. 30 ”,“ floor plate 32 ”, pillar constituent piece 34, and“ intervening portion 36 ”are included.

As shown in FIG. 2, the inner piece 28 is provided integrally with the "end portion 24A" on the lower side in the height direction of the leg member 24. The inner piece 28 is made of precast concrete and has a prismatic shape extending in the height direction. A spiral bar 30 is arranged on the outer peripheral side of the inner piece 28, as will be described later.

More specifically, the inner piece 28 has an octagonal shape in which the four corners of the square are cut out in an isosceles triangle shape when viewed from the height direction, and the outer peripheral surface, that is, the "plane 28A" on the spiral muscle 30 side. Is provided with "recesses 38" as a plurality of inner recesses. The recesses 38 are formed in an annular shape along the circumferential direction of the surface 28A when viewed from the height direction, and a plurality of the recesses 38 are arranged in the height direction.

On the other hand, as shown in FIG. 3, in the leg member 24, the main body portion 40 made of angle steel and the base portion 42 made of flat steel are joined at a joint portion (not shown) by welding or the like. The main part is composed of. More specifically, in the main body 40, the lower portion in the height direction is embedded in the inner piece 28, and the upper portion in the height direction is exposed from the inner piece 28 and extends to the upper side of the tower 10. Further, a plurality of bearing plates 44 made of angle steel are attached to the main body portion 40 along the extending direction by mounting members (not shown).

The base portion 42 has an octagonal plate shape when viewed from the height direction, and its lower surface 42A is exposed from the inner piece 28, and a penetration portion 42B penetrated in the height direction is provided. Further, a plate-shaped support plate portion 46 having a plate thickness direction as a height direction is arranged on the lower side in the height direction of the base portion 42, and the upper surface of the support plate portion 46 in the height direction is flat. It is said to be "installation surface 46A".

Further, the installation surface 46A is formed with a protrusion 46B that can be fitted to the penetration portion 42B. In the base portion 42, the lower surface 42A is in contact with the installation surface 46A and the protrusion 46B is fitted into the penetration portion 42B. In the combined state, it is positioned with respect to the support plate portion 46. The lower surface of the inner piece 28 is also in contact with the installation surface 46A of the support plate portion 46.

On the other hand, as shown in FIGS. 1 and 6, the spiral bar 30 is made of a deformed steel bar, has an annular shape when viewed from the height direction, and has a spiral shape whose axial direction is the height direction. It is said that. The spiral bar 30 is arranged on the outer peripheral side of the inner piece 28. The spiral bar 30 may be made of round steel.

As shown in FIG. 1, the floor plate 32 has a disk shape in which a circular penetrating portion 48 is formed in the central portion when viewed from the height direction, and an inner piece is formed inside the penetrating portion 48. 28 and a spiral muscle 30 are arranged. That is, the "inner peripheral surface 32A" of the floor plate 32 is formed along the circumference having a center on the leg member 24 side when viewed from the height direction.

The floor plate 32 includes a plurality of (four as an example) "upper floor plate blocks 50" constituting the upper portion in the height direction and a plurality (four as an example) constituting the lower portion in the height direction. It is configured to include the "lower floor board block 52". The upper floor board block 50 and the lower floor board block 52 are both made of precast concrete.

Specifically, the upper floor board blocks 50 are arranged in a row on the outer peripheral side of the upper portion of the spiral bar 30 in the height direction along the circumferential direction of the spiral bar 30, and the adjacent upper floor board blocks 50 are in contact with each other. It is in a state of being touched.

As shown in FIG. 4, the upper floor plate block 50 is formed in a substantially fan shape in which the angle formed by the pair of side surfaces 50A located at the boundary between the upper floor plate blocks 50 when viewed from the height direction is 90 degrees. There is. Further, the side surface 50B on the spiral bar 30 side of the upper floor plate block 50 constitutes a part of the inner peripheral surface 32A, and the lower portion of the side surface 50B in the height direction is recessed outward in the radial direction of the spiral bar 30. In addition, a "recess 54" is provided as an inner recess extending in the circumferential direction of the spiral muscle 30.

On the other hand, the side surface 50C on the opposite side of the upper floor plate block 50 to the spiral bar 30 constitutes a part of the "outer peripheral surface 32B" of the floor plate 32, and the spiral bar 30 is on the lower portion of the side surface 50C in the height direction. A "recess 56" is provided as an outer recess extending in the radial direction of the spiral muscle 30 and extending in the circumferential direction.

Further, the "lower surface 50D" of the upper floor plate block 50, that is, the surface on the lower floor plate block 52 side, has a "recess 58" as an engaged portion that is recessed upward in the height direction and extends in the circumferential direction of the spiral muscle 30. Is formed.

Returning to FIG. 8, the upper floor plate block 50 is provided with a plurality of “upper reinforcing bars 60” and a plurality of “upper end bars 62”. Specifically, these upper reinforcing bars 60 are arranged so as to form a radial shape extending from the center side of the floor plate 32 when viewed from the height direction. Further, as shown in FIGS. 1 and 4, the upper reinforcing bar 60 is made of deformed steel bars, and also has “first upper vertical bar 60A”, “upper horizontal bar 60B” and “second upper vertical bar 60C”. It is composed including ". The upper reinforcing bar 60 may be made of round steel.

The first upper vertical bar 60A is arranged on the inner peripheral side of the spiral bar 30 and extends from the upper side in the height direction to the lower side in the height direction, and the upper reinforcing bar 60 has the height of the spiral bar 30. The upper part in the spiral direction is locked. Then, from the portion on the upper side in the height direction of the first upper vertical streak 60A, the upper horizontal streak 60B extends radially outward of the spiral streak 30 in succession with the first upper vertical streak 60A.

The upper lateral bar 60B constitutes a main portion of the upper reinforcing bar 60 and extends in the radial direction of the spiral bar 30 when viewed from the height direction. Then, from the radially outer portion of the spiral muscle 30 in the upper horizontal muscle 60B, the second upper vertical muscle 60C extends downward in the height direction in succession with the upper horizontal muscle 60B.

Although at least a part of the upper reinforcing bar 60 configured as described above is embedded in the upper floor plate block 50, the lower "end" in the height direction of the first upper vertical bar 60A and the second upper vertical bar 60C. The portion 60C1 ”is exposed to the upper floor plate block 50. Further, the lower portion of the second upper vertical bar 60C in the height direction is located at a position overlapping with the recess 56 of the upper floor plate block 50 when viewed from the height direction.

On the other hand, the upper end bar 62 is made of deformed steel bar and extends in an arc shape centered on the center of the floor plate 32 so as to be orthogonal to the upper horizontal bar 60B when viewed from the height direction, and is a spiral bar. They are arranged at intervals of 30 from each other in the radial direction. The upper end bar 62 is connected to the upper lateral bar 60B by a binding line or the like (not shown). That is, the upper end bar 62 connects the upper lateral bars 60B adjacent to each other in the circumferential direction of the spiral bar 30 in the circumferential direction. The upper end bar 62 may be made of round steel.

Further, the upper surface 50E of the upper floor plate block 50 has a portion on the side surface 50A side recessed downward in the height direction, and the end portion 62A of the upper end bar 62 is exposed to the upper floor plate block 50. .. Then, at the boundary between the upper floor board blocks 50, the upper end bar 62 provided on one upper floor board block 50 and the upper end bar 62 provided on the other upper floor board block 50 form a "circumferential joint portion". It is connected in the circumferential direction of the spiral bar 30 by the welded joint portion 64 ”.

On the other hand, the lower floor board block 52 is arranged in a row on the outer peripheral side of the lower portion of the spiral bar 30 in the height direction along the circumferential direction of the spiral bar 30, and the adjacent lower floor board block 52 is arranged. They are in contact with each other.

As shown in FIG. 5, the lower floor plate block 52 is formed in a substantially fan shape in which the angle formed by the pair of side surfaces 52A located at the boundary between the lower floor plate blocks 52 when viewed from the height direction is 90 degrees. Has been done. Further, the side surface 52B of the upper floor plate block 50 on the spiral bar 30 side constitutes a part of the inner peripheral surface 32A, and the lower portion of the side surface 52B in the height direction is recessed outward in the radial direction of the spiral bar 30. In addition, a "recess 66" is provided as an inner recess extending in the circumferential direction of the spiral muscle 30.

On the other hand, the side surface 52C of the lower floor plate block 52 opposite to the spiral bar 30 constitutes a part of the outer peripheral surface 32B of the floor plate 32, and the lower portion of the side surface 52C in the height direction is the spiral bar 30. A "recess 68" is provided as an outer recess extending inward in the radial direction and extending in the circumferential direction of the spiral muscle 30.

Further, on the "upper surface 52D" of the lower floor plate block 52, that is, the surface on the upper floor plate block 50 side, a "projection 52E" that protrudes upward in the height direction and extends in the circumferential direction of the spiral muscle 30 is formed. The protrusion 52E is engaged with the recess 58 of the upper floor plate block 50. By engaging the protrusion 52E with the recess 58, the relative displacement of the upper floor plate block 50 and the lower floor plate block 52 in the direction orthogonal to the height direction can be restricted.

Returning to FIG. 8, the lower floor plate block 52 is provided with a plurality of “lower reinforcing bars 70” and a plurality of “lower end bars 72”. Specifically, these lower reinforcing bars 70 are arranged so as to form a radial shape extending from the center side of the floor plate 32 when viewed from the height direction. Further, as shown in FIGS. 1 and 5, the lower reinforcing bar 70 is made of deformed steel bars, and also has “first lower vertical bar 70A”, “lower horizontal bar 70B” and “second lower bar”. It is configured to include a lateral vertical bar 70C ”. The lower reinforcing bar 70 may be made of round steel.

The first lower vertical bar 70A is arranged on the inner peripheral side of the spiral bar 30 and extends from the lower side in the height direction to the upper side in the height direction, and the lower reinforcing bar 70 has the spiral bar 30. The lower part in the height direction is locked. Then, from the lower portion in the height direction of the first lower vertical streak 70A, the lower horizontal streak 70B extends radially outward of the spiral streak 30 in succession with the first lower vertical streak 70A.

The lower lateral bar 70B constitutes a main portion of the lower reinforcing bar 70 and extends in the radial direction of the spiral bar 30 when viewed from the height direction. Then, from the radial outer portion of the spiral muscle 30 in the lower horizontal muscle 70B, the second lower vertical muscle 70C extends upward in the height direction in succession with the lower horizontal muscle 70B.

Although at least a part of the lower reinforcing bar 70 configured as described above is embedded in the lower floor plate block 52, the upper side in the height direction of the first lower vertical bar 70A and the second lower vertical bar 70C. The "end 70C1" of the above is in a state of being exposed to the lower floor plate block 52. Further, the upper portion of the second lower vertical bar 70C in the height direction is located at a position overlapping with the recess 68 of the lower floor plate block 52 when viewed from the height direction.

On the other hand, the lower end bar 72 is made of deformed steel bar and extends in an arc shape centered on the center of the floor plate 32 so as to be orthogonal to the lower horizontal bar 70B when viewed from the height direction, and is spiral. The streaks 30 are arranged at intervals from each other in the radial direction. The lower end bar 72 is connected to the lower horizontal bar 70B by a binding line or the like (not shown). That is, the lower end muscle 72 connects the lower lateral muscles 70B adjacent to each other in the circumferential direction of the spiral muscle 30 in the circumferential direction. The lower end bar 72 may be made of round steel.

Further, the lower reinforcing bar 70 is arranged so as to overlap the upper reinforcing bar 60 when viewed from the height direction, and the end portion 70C1 of the second lower vertical bar 70C is the end portion of the second upper vertical bar 60C. It is connected to 60C1 in the height direction by a "coupler 74" as a joint portion in the height direction. The coupler 74 is not shown in FIG. 8 in order to make it easier to understand the configurations of the upper reinforcing bar 60 and the lower reinforcing bar 70.

On the other hand, as shown in FIGS. 1 and 7, the prism constituent piece 34 is configured to include a "prism block 76" as a prism constituent and a plurality of prism anchoring bars 78. The pillar block 76 is made of precast concrete and is arranged on the upper side in the height direction of the floor plate 32, and constitutes a part of the "pillar 80" of the foundation portion 22. The pillar 80 extends in the extending direction of the leg member 24 and is configured to surround the leg member 24 when viewed from the height direction.

The pillar block 76 is formed in a ring shape whose inner circumference surrounds the inner peripheral surface 32A of the floor plate 32 when viewed from the height direction. The lower surface 76A of the pillar block 76 is a horizontal plane abutting on the upper surface 50E of the upper floor plate block 50, and the upper surface 76B of the pillar block 76 is orthogonal to the extending direction of the pillar 80. ing.

On the other hand, the prism fixing bar 78 is made of deformed steel bar, a part thereof is embedded in the prism block 76, and is arranged at a distance from each other in the circumferential direction of the spiral bar 30. The prism fixing bars 78 include a prism reinforcing bar 78A extending upward in the height direction of the prism block 76 and an "inner reinforcing bar 78B" extending downward in the height direction of the prism block 76. It is composed of and. The prism fixing bar 78 may be made of round steel.

The prism reinforcing bar 78A extends in the extending direction of the prism 80, and the inner reinforcing bar 78B extends in the height direction. The prism reinforcing bar 78A constitutes a part of the prism 80 and is used for fixing a prism component (not shown) attached to the upper side of the prism block 76 in the height direction.

On the other hand, the inner reinforcing bar 78B is arranged on the inner peripheral side of the spiral bar 30 at a position closer to the spiral bar 30 than the first upper vertical bar 60A and the first lower vertical bar 70A. Further, the inner reinforcing bar 78B has a "first plane 82" having an arbitrary position in the height direction in a range orthogonal to the first upper vertical bar 60A and a range orthogonal to the first lower vertical bar 70A. Is arranged so as to be hung between the position in the height direction and the "second plane 84" which is an arbitrary position.

Returning to FIG. 8, the intervening portion 36 is configured by filling concrete between the inner piece 28 and the floor plate 32, and is in close contact with the inner piece 28 and the floor plate 32. Further, as shown in FIG. 1, a spiral muscle 30, a first upper vertical muscle 60A, a first lower vertical muscle 70A, and an inner reinforcing muscle 78B are embedded in the intervening portion 36 configured as described above. It is in a state. Note that FIG. 1 does not show the intervening portion 36 in order to make it easier to understand the configuration of the floor plate 32 and the like.

(Action and effect of this embodiment)
Next, the operation and effect of this embodiment will be described.

In the present embodiment, as shown in FIG. 1, the inner piece 28 is provided integrally with the lower end portion 24A in the height direction of the leg member 24 forming a part of the steel frame leg portion 20 of the steel tower 10. ing. The inner piece 28 is made of precast concrete, and since the inner piece 28 is arranged on the flat installation surface 46A of the support plate portion 46, the inner piece 28 can be arranged on the installation surface 46A. The leg member 24 can be positioned.

Further, on the outer peripheral side of the inner piece 28, a spiral streak 30 which is annular when viewed from the height direction is arranged in a state where the axial direction is the height direction. A floor plate 32 is arranged on the outer peripheral side of the spiral bar 30, and a concrete intervening portion 36 is interposed between the inner piece 28 and the floor plate 32, and the intervening portion 36 is an inner piece. It is in close contact with 28 and the floor plate 32. Therefore, in the present embodiment, even if the pull-out load caused by the electric wire or the like suspended on the steel tower 10 acts on the leg member 24, the pull-out load can be supported by the weight of the floor plate 32. Further, the shear load acting on the leg member 24 can be supported by the spiral muscle 30.

By the way, in supporting the pulling load acting on the leg member 24, it is preferable that the weight of the floor plate 32 connected to the leg member 24 is large. Further, from the viewpoint of shortening the construction time, it is preferable to use precast concrete for the floor plate 32. On the other hand, when the steel tower 10 is constructed in a mountainous area or the like, the weight of the material that can be transported is limited, so that the weight of the precast concrete that can be used for the floor plate 32 is also limited.

Here, in the present embodiment, a plurality of upper floor board blocks 50 and lower floor board blocks 52 made of precast concrete are included. Specifically, the plurality of upper floor board blocks 50 are arranged on the outer peripheral side of the upper portion of the spiral bar 30 in the height direction in a state where the upper floor board blocks 50 are in contact with each other along the circumferential direction of the spiral bar 30. There is. On the other hand, the plurality of lower floor plate blocks 52 are arranged on the outer peripheral side of the lower portion in the height direction of the spiral muscle 30 in a state where the lower floor plate blocks 52 are in contact with each other along the circumferential direction of the spiral muscle 30. Has been done.

Therefore, in the present embodiment, the members constituting the floor plate 32 can be divided and transported, and as a result, the weight of the floor plate 32 is secured even when the steel tower 10 is constructed in a mountainous area or the like. Can be done.

By the way, when only the intervening portion 36 transmits the load from the leg member 24 side to the upper floor board block 50 and the lower floor board block 52, it acts on these between the upper floor board block 50 and the lower floor board block 52. It is conceivable that the magnitude of the load will be biased.

Here, in the present embodiment, the upper floor plate block 50 is provided with a plurality of upper reinforcing bars 60 partially embedded in the upper floor board block 50, and the upper reinforcing bars 60 are on the inner peripheral side of the spiral bar 30. It is provided with a first upper vertical streak 60A that is arranged in the above direction and extends from the upper side in the height direction to the lower side in the height direction. On the other hand, the lower floor plate block 52 is provided with a lower reinforcing bar 70 partially embedded in the lower floor board block 52, and the lower reinforcing bar 70 is arranged on the inner peripheral side of the spiral bar 30. It also has a first lower vertical streak 70A extending from the lower side in the height direction to the upper side in the height direction.

Further, on the inner peripheral side of the spiral bar 30, a plurality of inner reinforcing bars 78B of the prism fixing bar 78 are arranged along the circumferential direction of the spiral bar, and the inner reinforcing bars 78B are the first upper vertical bar 60A. It is laid between the orthogonal first plane 82 and the first lower vertical streak 70A and the orthogonal second plane 84. The first upper vertical bar 60A, the first lower vertical bar 70A, and the inner reinforcing bar 78B are embedded in the intervening portion 36.

Therefore, the first upper vertical bar 60A and the first lower vertical bar 70A are connected in the height direction via the inner reinforcing bar 78B and the intervening portion 36, and the upper floor board block 50 and the lower floor board block are connected. A load from the leg member 24 side is similarly transmitted to the 52 via the first upper vertical bar 60A, the first lower vertical bar 70A, and the inner reinforcing bar 78B. As a result, in the present embodiment, the load from the leg member 24 side can be supported by the entire floor plate 32.

Further, in the present embodiment, the recess 38 is provided on the surface 28A of the inner piece 28 on the spiral bar 30 side, and the recess 54 and the recess 66 are provided on the inner peripheral surface 32A of the floor plate 32 on the spiral bar 30 side. The recess 38, the recess 54, and the recess 66 are filled with concrete that constitutes a part of the intervening portion 36. That is, the intervening portion 36 is provided with a protruding portion protruding toward the inner piece 28 side and a protruding portion protruding toward the floor plate 32 side.

Therefore, the shearing force acting on the intervening portion 36 when the inner piece 28 and the floor plate 32 try to move relative to each other is supported by these protrusions provided on the intervening portion 36, and as a result, the intervening portion 36 is supported. The load due to the weight of the floor plate 32 can be easily transmitted to the inner piece 28 side through the floor plate 32.

Further, in the present embodiment, the protrusion 52E is formed on the upper surface 52D of the lower floor plate block 52, and the recess 58 to which the protrusion 52E can engage is formed on the lower surface 50D of the upper floor board block 50. .. Then, by engaging the protrusion 52E with the recess 58, the relative displacement of the upper floor plate block 50 and the lower floor plate block 52 in the direction orthogonal to the height direction is limited.

By the way, it is conceivable that the floor plate 32 generates a moment caused by the weight of the tower 10 and a reaction force from the ground 26 with respect to the weight, and a moment caused by an external force received by the tower 10. When the moment is generated in the floor plate 32 in a state where the relative displacement of the upper floor plate block 50 and the lower floor plate block 52 in the direction orthogonal to the height direction is not restricted, the upper floor plate block 50 and the lower floor plate block It is considered that slippage occurs between the floor plate 32 and the floor plate 32, making it difficult to support the moment with the entire floor plate 32.

Here, in the present embodiment, as described above, the protrusion 52E and the recess 58 limit the relative displacement of the upper floor plate block 50 and the lower floor plate block 52 in the direction orthogonal to the height direction, so that the floor plate is restricted. Even if the moment occurs in 32, the moment can be supported by the entire floor plate 32.

Further, in the present embodiment, the concave portion 56 and the concave portion 68 recessed on the spiral muscle 30 side are provided on the outer peripheral surface 32B on the side opposite to the spiral muscle 30 of the floor plate 32. Therefore, when the floor plate 32 is buried in the soil, the mortar and soil around the floor plate 32 are filled in the recesses 56 and 68. As a result, in the present embodiment, the mortar or soil filled in the recess 56 and the recess 68 can function as a resistance to the pulling load acting on the leg member 24.

Further, in the present embodiment, the upper reinforcing bar 60 provided in the upper floor plate block 50 includes an upper horizontal bar 60B continuous with the first upper vertical bar 60A, and the upper horizontal bar 60B is from the first upper vertical bar 60A. It extends radially outward of the spiral muscle 30. The upper lateral bar 60B adjacent to the spiral bar 30 in the circumferential direction is connected in the circumferential direction by the upper end bar 62. Therefore, in the present embodiment, the bearing capacity of the ground 26 against the pulling load acting on the leg member 24 can be transmitted to the entire upper floor plate block 50.

Further, the lower reinforcing bar 70 provided in the lower floor plate block 52 includes a lower horizontal bar 70B continuous with the first lower vertical bar 70A, and the lower horizontal bar 70B is the first lower vertical bar 70A. It extends outward from the spiral muscle 30 in the radial direction. Then, the lower horizontal bar 70B adjacent to the spiral bar 30 in the circumferential direction is connected in the circumferential direction by the lower end bar 72. Therefore, in the present embodiment, the bearing capacity of the ground 26 against the pulling load acting on the leg member 24 can be transmitted to the entire lower floor plate block 52.

Further, in the present embodiment, as shown in FIG. 8, at the boundary between the upper floor board blocks 50, the upper end streaks 62 provided on one upper floor board block 50 and the other upper floor board block 50 are provided. The upper end bar 62 is connected to the spiral bar 30 in the circumferential direction by the welded joint portion 64. Therefore, in the present embodiment, the pull-out load acting on the leg member 24 can be distributed and supported on the upper part of the floor plate 32.

Further, in the present embodiment, the upper reinforcing bar 60 provided in the upper floor plate block 50 includes a second upper vertical bar 60C continuous with the upper horizontal bar 60B, and the second upper vertical bar 60C is from the upper horizontal bar 60B. The end portion 60C1 on the lower side in the height direction is exposed from the floor plate 32 while extending downward in the height direction.

On the other hand, the lower reinforcing bar 70 provided in the lower floor plate block 52 includes a second lower vertical bar 70C continuous with the lower horizontal bar 70B, and the second lower vertical bar 70C is the lower horizontal bar 70B. The end 70C1 on the upper side in the height direction is exposed from the floor plate 32 while extending upward in the height direction from the floor plate 32. The second upper vertical bar 60C and the second lower vertical bar 70C are connected in the height direction by the coupler 74. Therefore, in the present embodiment, the pull-out load acting on the leg member 24 can be distributed and supported in the upper part and the lower part of the floor plate 32.

Further, in the present embodiment, by arranging the pillar block 76 made of precast concrete on the upper side in the height direction of the floor plate 32, a part of the pillar 80 surrounding the leg member 24 when viewed from the height direction is formed. Can be done. Further, the inner reinforcing bars 78B of the pillar fixing bars 78 are connected to each other in the circumferential direction by the prism block 76, and the inner reinforcing bars 78B can be positioned by the prism block 76. Therefore, in the present embodiment, the construction time can be shortened as compared with the configuration in which ready-mixed concrete is placed to construct the pillar 80.

In addition, in the present embodiment, as shown in FIG. 1, the inner peripheral surface 32A on the spiral muscle 30 side of the floor plate 32 is along the circumference having the center on the leg member 24 side when viewed from the height direction. It is formed. That is, the floor plate 32 is in a state in which a circular penetrating portion 48 is formed when viewed from the height direction. On the other hand, the inner circumference of the pillar block 76 has a circumferential shape surrounding the inner peripheral surface 32A of the floor plate 32 when viewed from the height direction. Therefore, when the prism block 76 is aligned with the floor plate 32, it is possible to prevent the prism block 76 from falling into the penetrating portion 48 of the floor plate 32.

Next, with reference to FIG. 1, an example of the procedure of the method of constructing the steel tower foundation structure according to the present embodiment is shown.

First, in the first step, the ground 26 is dug while retaining the soil to form a hole 86 in which the floor plate 32 is accommodated, and when the hole 86 reaches a predetermined depth, the hole 86 is placed at a predetermined position on the bottom 86A of the hole 86. The support plate portion 46 is arranged, and the inner piece 28 is placed on the installation surface 46A of the support plate portion 46.

Next, in the second step, a plurality of lower floor plate blocks 52 are arranged in a state of being in contact with each other so as to surround the inner piece 28 when viewed from the height direction, and a spiral in a state where the axial direction is the height direction. The streaks 30 are arranged so that the first lower vertical streak 70A is located on the inner peripheral side of the spiral streak 30 and the inner piece 28 is surrounded by the spiral streak 30.

Next, in the third step, a plurality of upper floor plate blocks 50 are in contact with each other so as to surround the inner piece 28 when viewed from the height direction, and the first upper vertical bar 60A is on the inner peripheral side of the spiral bar 30. Place it so that it is located at.

Next, in the fourth step, the prism constituent piece 34 is positioned with respect to the floor plate 32, and a plurality of inner reinforcing bars 78B are spirally laid between the first plane 82 and the second plane 84. Arranged at intervals along the circumferential direction of the spiral muscle 30 on the inner peripheral side of the muscle 30.

Next, in the fifth step, ready-mixed concrete is placed between the inner piece 28 and the floor plate 32, and a spiral bar 30, a first upper vertical bar 60A, and a first lower bar are placed between the inner piece 28 and the floor board 32. The intervening portion 36 in which the lateral longitudinal bar 70A and the medial reinforcing bar 78B are embedded is formed.

Then, in the sixth step, the foundation portion 22 of the steel tower 10 is completed by backfilling the excavated soil in the peripheral portion of the floor plate 32.

As described above, according to the tower foundation structure and the construction method thereof according to the present embodiment, the construction time required for the construction of the foundation portion 22 is shortened while securing the weight of the foundation portion 22 of the steel tower 10. Further, the materials constituting the foundation portion 22 can be easily transported.

<Second Embodiment>
Hereinafter, the steel tower foundation structure according to the second embodiment of the present invention will be described with reference to FIGS. 10 to 12. The same components as those of the first embodiment described above will be assigned the same number and the description thereof will be omitted.

The foundation portion 90 according to the present embodiment has basically the same configuration as the foundation portion 22 according to the first embodiment, but the "floor plate 92" has a square shape when viewed from the height direction.

The floorboard 92 has a plurality of (four as an example) "upper floorboard block 94" constituting the upper portion in the height direction and a plurality of (four as an example) "upper floor plate blocks 94" constituting the lower portion in the height direction. It is configured to include the lower floor board block 96 ”. The upper floor board block 94 and the lower floor board block 96 are both made of precast concrete.

The upper floor plate block 94 is formed in a substantially square shape in which the angle formed by the pair of side surfaces located at the boundary between the upper floor plate blocks 94 when viewed from the height direction is 90 degrees, and the corner portion on the leg member 24 side is formed. , It is in a state of being cut out in a fan shape.

Further, the "lower surface 94A" of the upper floor plate block 94 is formed with a "recess 98" as an engaged portion recessed upward in the height direction. The recess 98 has an arcuate shape in which the peripheral edge portion on the leg member 24 side extends along the spiral muscle 30 when viewed from the height direction, and the peripheral edge portion on the opposite side to the leg member 24 is formed. Is a right-angled shape that is convex on the opposite side of the leg member 24.

Further, the upper floor plate block 94 is provided with a plurality of "upper reinforcing bars 100" having the same configuration as the upper reinforcing bar 60 and a plurality of "upper end bars 102" having the same configuration as the upper end reinforcing bar 62. There is.

Specifically, in the present embodiment, the lengths of these upper reinforcing bars 100 are not constant, and the center of the floor plate 92 and the corners of the upper floor plate block 94 opposite to the leg member 24 when viewed from the height direction. As the angle (acute angle) formed by the straight line connecting the portion 94B becomes smaller, the length of the upper reinforcing bar 100 becomes longer.

Further, among the upper end bars 102, the upper end bars 102 arranged on the outermost peripheral side of the upper floor plate block 94 are bent at a right angle so as to be convex toward the corner portion 94B.

On the other hand, the lower floor plate block 96 has the same shape as the upper floor plate block 94 when viewed from the height direction, and the "upper surface 96A" has a "projection 96B" which is convex upward in the height direction. Is formed. The protrusion 96B is engaged with the recess 98 of the upper floor plate block 94. Then, by engaging the protrusion 96B with the recess 98, it is possible to limit the relative displacement of the upper floor plate block 94 and the lower floor plate block 96 in the direction orthogonal to the height direction and the relative rotation around the height direction. Has been done.

Further, the lower floor plate block 96 has a plurality of "lower reinforcing bars 104" having the same configuration as the lower reinforcing bar 70 and a plurality of "lower end reinforcing bars 106" having the same configuration as the lower end reinforcing bar 72. It is provided.

Specifically, in the present embodiment, the lengths of these lower reinforcing bars 104 are not constant, and when viewed from the height direction, the center of the floor plate 92 and the side opposite to the leg member 24 of the lower floor plate block 96. As the angle (acute angle) formed by the straight line connecting the corner portion 96C of the above becomes smaller, the length of the lower reinforcing bar 104 becomes longer.

Further, among the lower end bars 106, the lower end bars 106 arranged on the outermost peripheral side of the lower floor plate block 96 are bent at a right angle so as to be convex toward the corner 96C side. In FIG. 10, the welded joint portion 64 and the coupler 74 are not shown in order to make it easier to understand the configuration of the floor plate 92.

According to such a configuration, basically the same actions and effects as those of the above-described first embodiment are obtained except for the actions and effects due to the shape of the floor plate 32. Further, when the shape of the hole that can be dug in the ground 26 is limited to a rectangular shape, the shape of the floor plate 92 can be made to correspond to the shape of the hole.

Further, in the present embodiment, by engaging the protrusion 96B with the recess 98, the relative rotation of the upper floor plate block 94 and the lower floor plate block 96 in the height direction is restricted, and the twist generated in the floor plate 92 is prevented. Can be supported.

<Third Embodiment>
Hereinafter, the steel tower foundation structure according to the third embodiment of the present invention will be described with reference to FIG. The same components as those of the first embodiment described above will be assigned the same number and the description thereof will be omitted.

Although the foundation portion 110 according to the present embodiment has basically the same configuration as the foundation portion 22 according to the first embodiment, the "floor plate 112" is composed of the upper floor plate block 50 and the lower floor plate block 52. It is equipped with a plurality of precast concrete "intermediate floorboard blocks 114" arranged in between.

The intermediate floor plate blocks 114 are arranged in a row on the outer peripheral side of the central portion in the height direction of the spiral muscle 30 along the circumferential direction of the spiral muscle 30, and the adjacent intermediate floor plate blocks 114 are in contact with each other. It has become.

Further, the upper surface 114A of the intermediate floor plate block 114 is provided with a "projection 114B" as a first protrusion having the same configuration as the protrusion 52E, and the lower surface 114C of the intermediate floor plate block 114 is provided with a recess 58. A "recessed portion 116" is provided as a second engaged portion having the same configuration as that of the above.

According to such a configuration, the protrusion 114B of the intermediate floor board block 114 is engaged with the recess 58 of the upper floor board block 50, and the protrusion 52E of the lower floor board block 52 is engaged with the recess 116 of the intermediate floor board block 114. By being combined, the relative displacement of the intermediate floor plate block 114 with respect to the upper floor plate block 50 and the lower floor plate block 52 in the direction orthogonal to the height direction is limited. That is, in the present embodiment, the recess 58 functions as the first engaging portion, and the protrusion 52E functions as the second protrusion.

Therefore, also in this embodiment, basically the same actions and effects as those in the first embodiment described above are obtained. Further, in the present embodiment, the weight of the floor plate 112 can be increased by adding the intermediate floor plate block 114 between the upper floor plate block 50 and the lower floor plate block 52.

<Supplementary explanation of the above embodiment>
(1) In the above-described embodiment, the upper floor plate block is provided with the upper end bar, but depending on the specifications of the floor plate and the like, the upper floor plate block may not be provided with the upper end bar. Similarly, the lower floor plate block may not be provided with the lower end streaks.

(2) Further, in the above-described embodiment, the prism fixing bar 78 is positioned by the prism block 76, but the pillar fixing bar 78 is positioned by using a jig according to the specifications of the floor plate and the like. May be done.

(3) Further, in the above-described embodiment, the coupler 74 is used for connecting the second upper vertical bar and the second lower vertical bar, but the second upper vertical bar and the second lower vertical bar are used. The connection may be made with a welded joint.

(4) In addition, in the above-described embodiment, the upper floor plate block is formed with an engaged portion, and the lower floor plate block is formed with a protrusion engaged with the engaged portion. Not limited to this. That is, according to the specifications of the foundation portion and the like, a protrusion is formed on the upper floor plate block, and an engaged portion on which the protrusion can be engaged is formed on the lower floor plate block. You may. Further, the intermediate floor plate block is configured to have an engaged portion to which the protrusion of the upper floor plate block can be engaged and a protrusion to be engaged with the engaged portion of the lower floor plate block. May be.

10 Steel tower 20 Steel legs 24 Legs 24A End 28 Inner piece 28A Surface 30 Spiral bar 32 Floor plate 32A Inner peripheral surface 32B Outer surface 36 Intervening part 38 Recess (inner recess)
46A Installation surface 50 Upper floor board block 50D Lower surface (surface)
52 Lower floor board block 52D Upper surface (face)
52E protrusion (second protrusion)
54 Recess (inner recess)
56 Recess (outer recess)
58 Recessed part (engaged part, first engaged part)
60 Upper reinforcement 60A 1st upper vertical bar 60B Upper horizontal bar 60C 2nd upper vertical bar 60C1 End 62 Upper edge 64 Welded joint (circumferential joint)
66 Recess (inner recess)
68 Recess (outer recess)
70 Lower reinforcement 70A 1st lower vertical bar 70B Lower horizontal bar 70C 2nd lower vertical bar 70C1 End 72 Lower end 74 Coupler (height joint)
76 Prism block (prism component)
78B Inner reinforcement 80 Pillar 82 1st plane 84 2nd plane 92 Floor board 94 Upper floor board block 94A Bottom surface (face)
96 Lower floor board block 96A Upper surface (face)
96B Protrusion 98 Concave (engaged part)
100 Upper reinforcement 102 Upper end reinforcement 104 Lower reinforcement 106 Lower end reinforcement 112 Floor plate 114B Protrusion (first protrusion)
116 Recess (second engaged part)

Claims (11)

The leg lumber that forms part of the steel leg of the tower,
An inner piece made of precast concrete, which is integrally provided with the lower end of the tower in the leg member in the height direction and is arranged on a flat installation surface.
A spiral streak arranged on the outer peripheral side of the inner piece in a state where the steel tower is annular when viewed from the height direction and the axial direction is the height direction.
A part of the floor plate arranged on the outer peripheral side of the spiral muscle is formed, and a plurality of the floor plates of the spiral muscle are in contact with each other along the circumferential direction of the spiral muscle on the outer peripheral side of the upper portion in the height direction. Placed precast concrete upper floorboard block,
A precast concrete bottom that constitutes a part of the floor plate and is arranged in a state of being in contact with each other along the circumferential direction of the spiral muscle on the outer peripheral side of the lower portion of the spiral muscle in the height direction. Side floor board block and
A plurality of units having a first upper vertical bar that is partially embedded in the upper floor plate block, is arranged on the inner peripheral side of the spiral bar, and extends from the upper side in the height direction to the lower side in the height direction. With the upper reinforcement,
A part of the lower floor plate block is embedded, and a first lower vertical bar is provided which is arranged on the inner peripheral side of the spiral bar and extends from the lower side in the height direction to the upper side in the height direction. With the lower reinforcement,
A plurality of planes are arranged on the inner peripheral side of the spiral muscle along the circumferential direction of the spiral muscle, and between a first plane orthogonal to the first upper vertical muscle and a second plane orthogonal to the first lower vertical muscle. With the inner reinforcing bar hung on the
It is provided between the inner piece and the floor plate and is provided in close contact with the inner piece and the floor plate, and the spiral bar, the first upper vertical bar, the first lower vertical bar and the inner reinforcing bar. With embedded concrete intervening parts
Tower foundation structure with. An inner recess filled with concrete is provided on the surface of the inner piece on the spiral side and the inner peripheral surface of the floor plate on the side of the spiral.
The steel tower foundation structure according to claim 1. A protrusion protruding from the other is formed on one of the surface of the upper floor plate block on the lower floor plate block side and the surface of the lower floor plate block on the upper floor plate block side, and the other surface has a protrusion. An engaged portion to which the protrusion can be engaged is formed, and the protrusion is engaged with the engaged portion so that the upper floor plate block and the lower floor plate block are engaged with each other in the height direction. Relative displacement in orthogonal directions can be restricted,
The steel tower foundation structure according to claim 1 or 2. A plurality of floor plates are arranged between the upper floor plate block and the lower floor plate block, form a part of the floor plate, and are in contact with each other on the outer peripheral side of the spiral muscle along the circumferential direction of the spiral muscle. Further equipped with precast concrete intermediate floorboard blocks placed in state,
A first protrusion projecting from the other is formed on one of the surface of the upper floor plate block on the intermediate floor plate block side and the surface of the intermediate floor plate block on the upper floor plate block side, and the other surface is formed with a first protrusion. A first engaged portion to which the first protrusion can be engaged is formed, and the first protrusion is engaged with the first engaged portion to engage the upper floor plate block and the intermediate floor plate block. It is possible to limit the relative displacement in the direction orthogonal to the height direction.
A second protrusion projecting from the other is formed on one of the surface of the intermediate floor plate block on the lower floor plate block side and the surface of the lower floor plate block on the intermediate floor plate block side, and the other. A second engaged portion to which the second protrusion can be engaged is formed, and the second protrusion is engaged with the second engaged portion to engage the intermediate floor plate block and the lower portion. It is possible to limit the relative displacement of the side floor board block in the direction orthogonal to the height direction.
The steel tower foundation structure according to claim 1 or 2. On the outer peripheral surface of the floor plate opposite to the spiral muscle, an outer concave portion recessed on the spiral muscle side is provided.
The steel tower foundation structure according to any one of claims 1 to 4. The upper reinforcing bar comprises an upper lateral bar that is continuous with the first upper vertical bar and extends radially outward from the first upper vertical bar.
The lower reinforcing bar includes a lower horizontal bar that is continuous with the first lower vertical bar and extends radially outward from the first lower vertical bar.
It further has an upper end bar connecting the upper lateral bar adjacent to the spiral direction in the circumferential direction and a lower end bar connecting the lower lateral bar adjacent to the circumferential direction in the circumferential direction.
The steel tower foundation structure according to any one of claims 1 to 5. At the boundary between the upper floor board blocks, a circumferential joint portion that connects the upper end bar provided on one upper floor board block and the upper end bar provided on the other upper floor board block in the circumferential direction. Have more,
The steel tower foundation structure according to claim 6. The upper reinforcing bar is a second upper vertical bar that is continuous with the upper horizontal bar and extends downward from the upper horizontal bar in the height direction and whose lower end in the height direction is exposed from the floor plate. Prepare,
The lower reinforcing bar is continuous with the lower horizontal bar and extends upward in the height direction from the lower horizontal bar, and the upper end in the height direction is exposed from the floor plate. With a line
Further having a height direction joint portion connecting the second upper vertical bar and the second lower vertical bar in the height direction.
The steel tower foundation structure according to claim 6 or 7. Precast that is arranged on the upper side of the floor plate in the height direction and forms a part of a prism that surrounds the leg member when viewed from the height direction, and connects the inner reinforcing bars to each other in the circumferential direction of the spiral bar. It also has a concrete pillar component,
The steel tower foundation structure according to any one of claims 1 to 8. The inner peripheral surface of the floor plate on the spiral muscle side is formed along the circumference having a center on the leg member side when viewed from the height direction.
The inner circumference of the pillar constituent portion has a circumferential shape surrounding the inner peripheral surface when viewed from the height direction.
The steel tower foundation structure according to claim 9. An inner piece made of precast concrete, which is integrally provided with one end of the leg material that forms a part of the steel leg of the tower, is placed on a flat installation surface.
A plurality of precast concrete lower floorboard blocks constituting a part of the floorboard are arranged so as to surround the inner piece when viewed from the height direction of the tower so as to be in contact with each other.
A spiral bar whose axial direction is the height direction is provided on the lower floor plate block, and is extended from the lower side in the height direction to the upper side in the height direction on the inner piece side of the lower floor plate block. The first lower vertical streak is arranged so as to be located on the inner peripheral side of the spiral streak and the inner piece is surrounded by the spiral streak.
A plurality of precast concrete upper floorboard blocks constituting a part of the floorboard are in contact with each other so as to surround the inner piece when viewed from the height direction, and the first upper side is provided on the upper floorboard block. Arrange the vertical streaks so that they are located on the inner peripheral side of the spiral streaks.
A plurality of inner reinforcing bars extending in the height direction are laid between a first plane orthogonal to the first upper vertical bar and a second plane orthogonal to the first lower vertical bar. Arranged at intervals along the circumferential direction of the spiral muscle on the inner peripheral side of the spiral muscle.
Place ready-mixed concrete between the inner piece and the floorboard.
How to build a tower foundation structure.

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