JP4494282B2 - Tower structure with variable cross section by precast method - Google Patents

Description

  The present invention relates to a tower structure having a variable cross section such as a wind power generation tower constructed using a precast concrete member (hereinafter also referred to as PCa concrete).

  In recent years, actions to suppress carbon dioxide gas emissions have been urged to prevent global warming, and wind power generation has been introduced all over the world as a clean power supply source. For example, the European Wind Energy Association has set a goal of supplying 12% of world electricity by wind power by 2020, while Japan aims to introduce 3 million kW (1500 units in 2000kW class windmill conversion) by 2010. (See Non-Patent Document 6 below), and it is thought that the introduction of wind power generation by power companies and public and private capital will continue to be accelerated.

  By the way, in the construction of the wind power generation tower, a steel tower has been generally used. However, it is excellent in terms of economy, high rigidity, high durability, and does not require regular maintenance. Many demands for power generation towers are expected in the future. In addition, when a construction method using a precast member made of concrete (precast construction method) is adopted, it also corresponds to a request for rapid construction.

  For example, the following Patent Document 1 discloses a structure of a wind power generation tower in which a circular segment made of precast concrete having the same diameter is sequentially fastened with a PC steel bar and stacked in the height direction to construct a tower. .

  Further, in Patent Document 2 below, a plurality of concrete cylindrical segments are stacked and connected to each other, and the cylindrical segment group is integrated by introducing pre-stress by a post-tension method to the plurality of cylindrical segments. A precast concrete windmill support tower is disclosed. In the example shown in the figure, the tower shown in this document has a variable cross-sectional shape in which the cross-sectional dimension is reduced in a taper shape in the height direction.

  Furthermore, in the following Patent Document 3, a large number of concrete hollow cylinders having the same cross-sectional shape are stacked, and a tower body is constructed by introducing a prestressed structure. There is disclosed a structure of a concrete wind power generation tower in which a concrete reinforcing block (for example, a T-shaped block) is provided to reinforce a base portion.

  Hereinafter, in Patent Document 4, a cylindrical unit composed of a steel pipe part and a precast concrete part covering the outer surface of the steel pipe part is stacked and connected concentrically in the vertical direction, and the steel pipe part is in the vertical direction. A tower-like structure formed by joining is disclosed. In such a tower-like structure, the weight of the concrete is reduced by gradually reducing the outer diameter of the cylindrical units stacked in the vertical direction (the inner diameter is the same in the height direction).

In the following Patent Document 5, a variable cross-section precast molded body whose cross-sectional dimensions are gradually reduced in a taper shape toward the upper side using a variable form is manufactured at a factory or the like for each block. It is illustrated that a wind power generation tower whose cross-sectional dimension is linearly reduced in the height direction is constructed by stacking in the height direction (see FIG. 3 of the same document).
Utility model registration No. 3074144 JP 2000-283019 A JP 2002-122066 A JP 2004-19306 A JP 2005-30066 A Ushiyama, “Toward the Practical Use of Wind Power Generation”, Civil Engineering Journal 2004.8, August 2004, p.7-11

  The tower structures described in Patent Documents 1 to 5 all require the advantages of being a precast concrete tower, that is, structural characteristics such as economy, high rigidity and durability, maintenance, and rapid construction by precasting. To meet.

  By the way, the section of the wind power generation tower is determined so that it has sufficient structural resistance against external forces such as its own weight, wind load, and earthquake load as well as acting force due to the weight of the windmill part, but it acts on the tower. The cross-sectional force (especially the vertical force and bending moment) is relatively large on the base side and small on the upper end side. Therefore, if the cross-sectional shape of the tower is gradually reduced to the upper side, the base cross-sectional force can be reduced. In addition to being advantageous in terms of structure, it is possible to reduce the foundation structure and the production cost of precast concrete members, and to construct a tower at a low cost.

  Considering from such a viewpoint, the tower structure described in Patent Document 1 uses a segment made of precast concrete having an equal cross section in the height direction, which is structurally disadvantageous because the base section force cannot be reduced. At the same time, the production cost of the precast concrete member cannot be reduced.

  Although the wind turbine tower structure described in Patent Document 2 is structurally excellent in that the tower shape is a variable cross-sectional shape in which the cross-sectional dimension is gradually reduced in the height direction, the cross-sectional dimension for each cylindrical segment to be stacked is excellent. However, since the formwork costs for manufacturing individual cylindrical segments increase, the segment manufacturing costs increase conversely.

  The wind power generation tower structure described in Patent Document 3 uses a concrete hollow cylinder having the same cross-sectional shape, and reinforces only the base with a reinforcing block, which is structurally advantageous because it can reduce the base cross-sectional force, Although it will be possible to reduce the basic structure and the cost of manufacturing precast concrete members, it requires installation work of the reinforcement block separately from the tower body work. It will take extra time and the construction period will be extended.

  The tower-like structure described in Patent Document 4 has a tower shape with a variable cross-sectional shape in the height direction, but the joining between the cylindrical units joins the steel pipe parts by welding. Accordingly, since the steel pipe portion bears a tensile stress due to a bending moment, the steel pipe joint needs to be completely penetrated and there is a problem that quality control of welding cannot be sufficiently performed. In addition, the same document suggests that prestress is introduced by passing a PC steel rod through the cross section of the precast block [see paragraph 0017]. In this case, the inner diameter of each cylindrical unit is the same in the height direction. Therefore, it is impossible to reduce the size (light weight) of the cylindrical unit, and it is impossible to reduce the basic structure and the production cost of the precast concrete member.

  The wind power generation tower described in Patent Document 5 is intended to reduce the number of molds and reduce the production cost by using a specific formwork device to produce the variable cross-section precast molded body. Compared to hollow precast reinforced concrete products that are centrifugally molded at the factory, the production costs are still high.

Therefore, a main problem of the present invention is that a tower-like structure in which a plurality of precast cylindrical bodies made of concrete are stacked in the height direction and each precast cylindrical body is fastened and integrated with a PC steel material. In the height direction, the block is divided into one or a plurality of precast cylinders, and the outer diameter dimension is gradually reduced in the height direction for each block, and the weight of each precast cylinder is reduced. Another object of the present invention is to provide a tower structure having a variable cross section by a precast method that can reduce the cost and ensure continuity as a structure.

In order to solve the above-mentioned problems, the present invention according to claim 1 is a tower-like structure in which a plurality of precast cylindrical bodies made of concrete are stacked in the height direction, and each precast cylindrical body is fastened and integrated with a PC steel material. In things,
The tower-like structure is divided into blocks in the height direction for each of one or a plurality of precast cylindrical bodies, and each block has a variable cross-sectional shape whose outer diameter dimension is gradually reduced in the height direction. In the block, the precast cylindrical body is stacked under the condition of using a precast cylindrical body having the same outer diameter cross section in the member axial direction, and at each boundary part divided into blocks, the uppermost part in the lower block, While having substantially the same outer diameter dimension as the lower-stage precast cylindrical body and interposing a boundary portion precast cylindrical body having the same cross section in the member axial direction,
The boundary part precast cylindrical body fixes the PC steel material extended from the lower side precast cylindrical body side to the upper surface outer peripheral portion, and fixes the PC steel material extended to the upper stage side precast cylindrical body side to the lower surface inner peripheral portion. The PC steel material extended from the lower-stage precast cylindrical body side and the PC steel material extended to the upper-stage precast cylindrical body side are arranged with an overlap in the member axial direction in the boundary portion precast cylindrical body. There is provided a variable cross-section tower structure by a precast method characterized by the above.

  In the first aspect of the present invention, first, the tower-like structure is divided into blocks in the height direction for each of one or a plurality of precast cylindrical bodies, and the precast having the same outer diameter cross section in the member axial direction in each block. By stacking the precast cylindrical body under the condition of using the cylindrical body, the outer diameter dimension is gradually reduced in the height direction, and at the boundary portion where the cross section changes, PC steel material extended from the side precast cylindrical body side is fixed to the upper surface outer peripheral portion, and a boundary portion precast cylindrical body is fixed to fix the PC steel material extended to the upper stage side precast cylindrical body side to the lower surface inner peripheral portion. Thus, the continuity of stress and the continuity of construction as a structure are ensured.

  In each block, a precast cylindrical body having the same cross section in the axial direction is used. Therefore, a precast cylindrical body manufactured by using a common formwork or centrifugal molding can be used for manufacturing. Can be reduced.

As the present invention according to claim 2, in the tower-like structure in which a plurality of precast cylindrical bodies made of concrete are stacked in the height direction, and each precast cylindrical body is tightly coupled by PC steel,
The tower-like structure is divided into blocks in the height direction for each of one or a plurality of precast cylindrical bodies, and each block has a variable cross-sectional shape whose outer diameter dimension is gradually reduced in the height direction. Of the blocks, the lowermost block uses a precast cylindrical body having the same outer diameter cross section in the member axial direction. In each block except the lowermost block, the precast cylindrical body arranged at the lowermost portion is in the member axial direction. The cross-sectional shape is formed by gradually reducing the outer diameter dimension in a taper shape as it goes upward while the inner diameter dimension is the same, and the other conditions are the same under the conditions of using a precast cylindrical body having the same outer diameter section in the member axial direction. Precast cylindrical bodies are stacked, and each block is divided into blocks, with the same outer diameter as the lower precast cylindrical body at the top of the lower block and the same in the member axial direction The boundary precast tubular body which is the surface is interposed,
The boundary portion precast tubular body fixes the PC steel material extended from the lower side precast cylindrical body side to the upper surface outer peripheral portion, and fixes the PC steel material extended to the upper stage side precast cylindrical body side to the lower surface inner peripheral portion. The PC steel material extended from the lower-stage precast cylindrical body side and the PC steel material extended to the upper-stage precast cylindrical body side are arranged with an overlap in the member axial direction in the boundary portion precast cylindrical body. Thus, there is provided a variable cross-section tower structure by the precast method.
In the invention according to the second aspect, the outer diameter is reduced in a tapered appearance at the boundary portion.

As the present invention according to claim 3, in the boundary portion Precast cylindrical body, and a PC steel which is disposed on the outer peripheral side, one of claims 1, 2 and PC steel which is disposed on the inner peripheral side in a staggered arrangement variable cross-section in column-like structure according precast method of crab described is provided.

In the invention of claim 3 , in the boundary portion precast tubular body, the PC steel material arranged on the outer peripheral side and the PC steel material arranged on the inner peripheral side are arranged in a staggered arrangement to thereby apply the tensile stress. It becomes possible to equalize in the circumferential direction.

As the present invention according to claim 4, wherein the PC steel material, the inner cable type disposed skeleton body of the precast cylindrical body along the entire length, the boundary portion precast cylindrical body the upper stage side precast cylindrical body When variable cross-section in column-like structure according precast construction method is provided according to substantially the same inner diameter as the claim 1-3 or it has.

In the present invention according to the fourth aspect , the PC steel material is an inner cable type disposed in the housing of the precast tubular body over the entire length, and in this case, the boundary portion precast tubular body is provided. and substantially the same inner diameter as the upper stage side precast tubular body. The boundary precast cylindrical body can ensure a sufficient wall thickness for fixing each of the PC steel material extended to the lower side and the PC steel material extended to the upper side, and the precast cylinder on the lower side Each of the cylindrical body and the upper-stage precast cylindrical body can be designed with a cross-sectional dimension necessary for the structure, and the flow of stress at the cross-section changing portion can be made continuous.

As the present invention according to claim 5 , the PC steel material is an out cable type in which an intermediate portion other than the fixing portion and the vicinity thereof is exposed outside the housing of the precast cylindrical body, and at least each boundary portion precast cylindrical body and About the precast cylindrical bodies adjacent, claim 1-3 or with a sectional shape having a cable insertion skeleton portion which is thickened on an inner wall side of the precast cylindrical body such that the PC steel material is inserted a skeleton body A tower structure having a variable cross section by the precast method described in 1. is provided.

In the present invention described in claim 5 , the PC steel is an out-cable type in which the intermediate portion other than the fixing portion and the vicinity thereof is exposed outside the precast cylindrical body. In this case, the boundary portion precast is used. In order to connect the cylindrical body and the precast cylindrical body adjacent vertically, at least the precast cylindrical body adjacent vertically, the PC steel material is placed on the inner wall side of the precast cylindrical body so as to pass through the housing. It is set as the cross-sectional shape which has the cable insertion casing part thickened.

As described above in detail, according to the present invention, in each block, a tower structure having a variable cross section can be constructed as a whole while using a member having the same cross section in the axial direction for each precast cylindrical body. At this time, the PC steel material extended from the lower side precast cylindrical body side is fixed to the upper surface outer peripheral portion at each variable cross section boundary portion, and the PC steel material extended to the upper stage side precast cylindrical body side is fixed to the lower surface inner peripheral portion. Since the boundary precast cylindrical body is interposed, the continuity as a structure can be ensured.

  In addition, the boundary portion precast cylindrical body has substantially the same outer diameter as that of the lower-stage precast cylindrical body, and substantially the same inner diameter dimension as that of the upper-stage precast cylindrical body. The wall thickness for fixing each PC steel material to be extended can be secured without excess or deficiency, and the precast cylindrical body on the lower side and the precast cylindrical body on the upper side can be designed with cross-sectional dimensions required for the structure. Therefore, each precast tubular body can be reduced in weight and cost.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  1 is a front view of the wind power generation facility 1, FIG. 2 is a longitudinal sectional view, a plan view, and a bottom view of the precast tubular bodies 5 to 8 of the tower 4, FIG. 3 is an enlarged longitudinal sectional view of a joint portion, and FIG. It is the longitudinal cross-sectional view, top view, and bottom view of boundary part precast cylindrical bodies 9-11.

  The wind power generation facility 1 includes a rotor blade 2 that rotates by receiving wind, a nacelle 3 having a power generation facility and its control facility, and a tower 4 (a tower structure) that supports the rotor blade 2 and the nacelle 3.

The tower 4, between the coupling portion 13 of the base portion 12 and the nacelle 3, 1 or more in the height direction, divided into blocks B ₁ ~ are each 5-8 precast cylindrical body 2-3 in the illustrated embodiment B ₄ and, under the conditions in the respective blocks B ₁ .about.B ₄ to use precast cylindrical body 5-8 of the same cross-section in the member axis, with stacking the precast cylindrical body 5-8 is divided into blocks Further, by providing the boundary portion precast tubular bodies 9 to 11 at each boundary portion, the outer diameter dimension is gradually reduced stepwise in the height direction.

As shown in FIG. 2, the precast cylindrical bodies 5 to 8 are circular cylindrical precast members having the same cross section in the axial direction for each block , and each is manufactured using the same formwork. Alternatively, a hollow precast member manufactured by centrifugal molding is used.

  In addition to the reinforcing bars 20, sheaths 21, 21... For inserting the PC steel rods 14 are embedded in the wall surface at appropriate intervals in the circumferential direction. A sheath widened portion 21a is formed at the lower end of the sheaths 21, 21... So that a coupler for connecting the PC steel rods 14 can be inserted, and a fixing anchor plate is fitted on the upper portion. A box opening portion 22 is provided for installation. In addition, a plurality of suspension fittings 23 are provided on the upper surface.

  As shown in FIG. 3 (A), the precast cylindrical bodies 5 to 8 are bonded to the sheaths 21 and 21 with the PC steel rods 14 and 14 extending upward from the lower-stage precast cylindrical bodies 5 to 8, respectively. When the precast cylindrical bodies 5 to 8 are stacked while being inserted through the anchor plate 24, the anchor plate 24 is fitted into the box opening portion 22, and the nut member 25 introduces tension to the PC steel rod 14 to achieve integration. A grout material is injected into the sheath 21 from the grout injection hole 27. The hole 24a formed in the anchor plate 24 is a grout injection confirmation hole, and the filling of the grout material is completed when the grout material is discharged from the confirmation hole.

  Next, as shown in FIG. 3 (B), if the coupler 26 is screwed into the protruding portion of the PC steel bar 14 and the upper PC steel bars 14, 14. The PC steel rods 14, 14 ... are stacked while being inserted through the sheaths 21, 21 ... of the precast cylindrical bodies 5-8, and the procedure for fixing the PC steel rod 14 according to the above procedure is sequentially repeated to pile up in the height direction. It is done. At this time, an adhesive 15 such as an epoxy resin or a sealing material is applied to the joint surface between the lower-stage precast tubular body and the upper-stage precast tubular body in order to ensure waterproofness and join the mating surfaces.

  On the other hand, as shown in FIG. 4, the boundary portion precast cylindrical bodies 9 to 11 are cylindrical precast members having the same cross section in the member axial direction, like the precast cylindrical bodies 5 to 8. The hollow precast member manufactured by using the same mold or each of which is manufactured by centrifugal molding is used, but the outer diameter dimension is substantially the same as that of the lower precast cylindrical body, and the upper precast cylinder is used. It has a cross-sectional shape having the same inner diameter as that of the body.

  In addition to the reinforcing bars 20, sheaths 21, 21... For inserting PC steel bars at appropriate intervals in the circumferential direction are embedded in the wall surface. A sheath diameter-enlarged portion 21 a is formed at the lower end portion of the sheaths 21, 21... And a box opening portion 22 for fitting a fixing anchor plate is formed at the upper portion. A plurality of suspension fittings (not shown) are provided on the upper surface.

  Further, on the relatively inner peripheral side of the wall surface, unbonded PC steel fixed to the lower surface side of the boundary portion precast tubular body 9 (10 to 11) by the anchor plate 30 and the nut 29 at an appropriate interval in the circumferential direction. Bars 28, 28 ... are embedded in advance. The upper end of the unbonded PC steel bar 28 is formed so as to protrude from the upper surface of the boundary portion precast cylindrical body 9 (10 to 11). Also, the positions of the outer sheaths 21, 21... And the unbonded PC steel bars 28, 28... Are arranged in a staggered manner in order to equalize the tension stress.

  The tightly coupled portion structure of the boundary portion precast tubular body 9 (10, 11), the lower stage precast tubular body 5 (6, 7), and the upper stage precast tubular body 6 (7, 8) The PC steel material 14 extended from the precast cylindrical body 5 (6, 7) side is fixed to the outer periphery of the upper surface of the boundary precast cylindrical body 9 (10, 11), and the upper precast cylindrical body 6 (7 8) The PC steel material (unbonded PC steel rod 28) extending to the side is fixed to the inner peripheral portion of the lower surface of the boundary precast cylindrical body 9 (10, 11).

  Specifically, as shown in FIG. 5 (typically described by the boundary portion precast tubular body 9), the PC steel rods 14, 14... .., 21..., 21..., 21... Are stacked, the anchor plate 24 is fitted into the box opening 22, and the nut member 25 introduces tension to the PC steel bars 14, 14. Integrate. At this time, the adhesive 15 or the sealing material is applied to the mating surfaces of the precast cylindrical bodies 5 and 9 so that the tension introducing force is always full prestress with respect to the cross-sectional action force, and during storms and earthquakes. Etc. shall be partial pre-stress. In addition, a grout material is injected into the sheath 21 from the grout injection hole 32, and the exposed nut 25 is covered with a cap material 31 and filled with grease or the like for rust prevention treatment.

  Next, when the coupler 33 is screwed into the upper end portion of the unbonded PC steel rod 28 and the upper PC steel rods 14, 14... Are connected, the PC steel is attached to the sheaths 21, 21. The rods 14 are stacked while being inserted, and the PC steel rod 14 is fixed in the manner described above, and the upper precast tubular body 6 is integrally coupled to the boundary precast tubular body 9.

[Other examples]
(1) In the above embodiment, in each of the boundary portions precast cylindrical body 9 (10, 11) portion comprising a reduced cross section, but so as to form a stair-shaped step portion, the boundary portion precast cylindrical body 9 In the (10, 11) portion , the outer diameter can be reduced in a tapered appearance. FIGS. 6A and 6B show structural examples in that case. First, FIG. 6A shows a precast tower-like body 6 ′ (7 ′, 8 ′) loaded on the upper side, with the same inner diameter and the outer diameter being gradually reduced toward the upper side. It is a shape. In this case, the box opening portion 6a (7a, 8a) is formed at a portion corresponding to the fixing portion of the lower PC steel rod 14, and is installed in a state filled with grease or the like for rust prevention treatment.

  Next, in the example shown in FIG. 6B, as the precast tower 6 '(7', 8 ') loaded on the upper stage side, the inner diameter dimension is the same, and the outer diameter dimension gradually increases toward the upper side. In addition to a reduced cross-sectional shape, a U-shaped notch 6b (7b, 8b) is formed in the fixing portion of the lower PC steel rod 14 in a plan view. In this case, the exposed nut 25 is covered with a cap material 31 and filled with grease or the like for rust prevention treatment.

(2) In the above embodiment, each of the PC steel bars 14 and 28 is an inner type installed in the precast tubular body 5-8, but as shown in FIG. Then, it is also possible to set it as the outer type arrange | positioned inside from the housing of the precast cylindrical bodies 5-8. Also in this case, similarly to the inner type, in each boundary portion precast cylindrical body 9 (10, 11), the PC steel material 14 extended from the lower-stage side precast cylindrical body side 5 (6, 7) is replaced with the boundary portion precast cylindrical body. PC steel material 14 is fixed to the outer peripheral portion of the upper surface of the cylindrical body 9 (10, 11) and extended to the upper precast cylindrical body side 6 (7, 8). The boundary precast cylindrical body 9 (10, 11) May be fixed to the inner peripheral portion of the lower surface of the rim, but it is connected between the precast cylindrical bodies 9, 10, 11 and the adjacent precast cylindrical bodies 6, 7, 8 (5, 6, 7). In addition, since there is a possibility that the shear strength cannot be secured, the precast cylindrical bodies 6, 7, 8 (5, 6, 7) adjacent to the boundary precast cylindrical bodies 9, 10, 11 are vertically , PC steel 1 So they inserted the building frame body, it is desirable to cross-sectional shape having a cable insertion skeleton portion 34 thickened on the inner wall of the precast cylindrical body 6, 7, and 8 (5,6,7). In addition, since the shear strength by the PC steel material 14 cannot be expected at the joint portion between the precast cylindrical bodies 5 to 8 having the same cross section, a reinforcing bar or the like is disposed so as to straddle the boundary portion, or a shear key by unevenness is provided. Is desirable.

(3) In the above embodiment, the case where the tower cross section is circular has been described. However, the present invention can be applied to any cross section such as a polygonal cross section or an elliptical cross section.

(4) In the above embodiment, the unbonded PC steel rod 28 is embedded in the boundary portion precast cylindrical body 9 (10, 11) in advance, but the sheath 21 is embedded in the same manner as the others, and the PC steel rod 14 is inserted. Then, it may be fixed.

  The present invention is suitable for wind power generation towers, but can also be applied to tower structures such as bridge pier structures and chimneys.

1 is a front view of a wind power generation facility 1. FIG. The precast cylindrical bodies 5-8 of the tower 4 are shown, (A) is a longitudinal cross-sectional view, (B) is a plan view (BB line arrow view), (C) is a bottom view (CC line arrow view). . It is a binding procedure diagram of the precast tubular body 5 (6, 7, 8). The boundary part precast cylindrical body 9 (10, 11) is shown, (A) is a longitudinal sectional view, (B) is a plan view (BB line arrow view), (C) is a bottom view (CC line arrow view). It is. It is an expanded vertical sectional view which shows the binding part structure of the boundary part precast cylindrical body 9 (10, 11). (A) (B) is a longitudinal cross-sectional view which shows the example of joining with a boundary part precast cylindrical body. It is a principal part longitudinal cross-sectional view at the time of arrange | positioning PC steel bar by an outer type.

  DESCRIPTION OF SYMBOLS 1 ... Wind power generation equipment, 2 ... Rotor blade, 3 ... Nacelle, 4 ... Tower, 5-8 ... Precast cylindrical body, 9-11 ... Precast cylindrical body, 14 ... PC steel rod, 21 ... Sheath, 21a ... Sheath diameter enlarged part, 24 ... Anchor plate, 25 ... Nut, 33 ... Coupler, 28 ... Unbond PC steel

Claims (5)

In a tower-like structure in which a plurality of precast cylindrical bodies made of concrete are stacked in the height direction, and each precast cylindrical body is tightly coupled with PC steel to achieve integration,
The tower-like structure is divided into blocks in the height direction for each of one or a plurality of precast cylindrical bodies, and each block has a variable cross-sectional shape whose outer diameter dimension is gradually reduced in the height direction. In the block, the precast cylindrical body is stacked under the condition of using a precast cylindrical body having the same outer diameter cross section in the member axial direction, and each block divided into the uppermost part in the lower block, While having substantially the same outer diameter dimension as the lower-stage precast cylindrical body and interposing a boundary portion precast cylindrical body having the same cross section in the member axial direction,
The boundary portion precast tubular body fixes the PC steel material extended from the lower side precast cylindrical body side to the upper surface outer peripheral portion, and fixes the PC steel material extended to the upper stage side precast cylindrical body side to the lower surface inner peripheral portion. The PC steel material extended from the lower-stage precast cylindrical body side and the PC steel material extended to the upper-stage precast cylindrical body side are arranged with an overlap in the member axial direction in the boundary portion precast cylindrical body. A tower structure with a variable cross section by a precast method, characterized by In a tower-shaped structure in which a plurality of precast cylindrical bodies made of concrete are stacked in the height direction, and each precast cylindrical body is tightly coupled with PC steel to achieve integration,
The tower-like structure is divided into blocks in the height direction for each of one or a plurality of precast cylindrical bodies, and each block has a variable cross-sectional shape whose outer diameter dimension is gradually reduced in the height direction. Of the blocks, the lowermost block uses a precast cylindrical body having the same outer diameter cross section in the member axial direction. In each block except the lowermost block, the precast cylindrical body arranged at the lowermost portion is in the member axial direction. The cross-sectional shape is formed by gradually reducing the outer diameter dimension in a taper shape as it goes upward while the inner diameter dimension is the same. Precast cylindrical bodies are stacked, and each block is divided into blocks, with the same outer diameter as the lower precast cylindrical body at the top of the lower block and the same in the member axial direction The boundary precast tubular body which is the surface is interposed,
The boundary part precast cylindrical body fixes the PC steel material extended from the lower side precast cylindrical body side to the upper surface outer peripheral portion, and fixes the PC steel material extended to the upper stage side precast cylindrical body side to the lower surface inner peripheral portion. The PC steel material extended from the lower-stage precast cylindrical body side and the PC steel material extended to the upper-stage precast cylindrical body side are arranged with an overlap in the member axial direction in the boundary portion precast cylindrical body. A tower structure with a variable cross section by a precast method, characterized by In the said boundary part precast cylindrical body, the PC steel materials arrange | positioned at the outer peripheral side and the PC steel materials arrange | positioned at an inner peripheral side are made into staggered arrangement, The cross section by the precast construction method in any one of Claims 1 and 2 Tower-like structure. The PC steel material, the inner cable type disposed skeleton body of the precast cylindrical body along the entire length, the boundary portion precast cylindrical body is set to substantially the same inner diameter as the upper stage side precast cylindrical body variable cross-section in column-like structure according precast method according to any one of claims 1-3. The PC steel material is an out cable type in which an intermediate portion other than the fixing portion and the vicinity thereof is exposed outside the housing of the precast cylindrical body, and at least the precast cylindrical body adjacent to each boundary portion precast cylindrical body in the vertical direction. The cross section tower by the precast construction method according to any one of claims 1 to 3 , wherein the PC steel material has a cross-sectional shape having a cable insertion casing portion thickened on the inner wall side of the precast cylindrical body so that the PC steel material is inserted through the casing. Structure.

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