JP3364822B2 - Construction method of steel frame reinforced concrete structure using thickened steel pipe - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION This invention various related facilities <br/> coating method of thickening the steel pipe used SRC structure which is applied to buildings.

[0002]

2. Description of the Related Art As a structure for increasing the yield strength of a steel pipe column, the column may be filled with concrete. Such a concrete-filled steel tubular column generally has a structure as shown in FIG.
The diaphragm 102 is provided at the beam joint of the steel pipe column 101,
It is adopted in the case of a column-beam joint structure in which the beam 103 is welded.
The diaphragm 102 is made of a rectangular steel plate, and the pillar 101 is divided into upper and lower parts, and the divided parts are interposed and welded.

[0003]

In the structure in which the diaphragm 102 is used for the column joint portion as described above, the steel pipe column 101 is divided as described above, and the diaphragm 102 is divided into the divided portions.
Since it is necessary to weld the beam, it takes time and effort to form the beam joint, and high quality control is also required. Therefore, the cost becomes high. On the other hand, the steel pipe concrete column as described above may not be able to obtain a sufficient required yield strength. Improving the proof stress by embedding a reinforcing bar is possible, but the diaphragm 10
2 is an obstacle and it is difficult to insert the reinforcing bar into the steel pipe column 101.

The present invention has been made to solve the above problems, and has as its object the improvement of yield strength, cost reduction, and facilitation of construction.

[0005]

A steel-framed reinforced concrete structure using a thickened steel pipe constructed by the method of the present invention has a thickened steel pipe in which a column has a thickened portion by heating and compression in a part in the longitudinal direction, and the inside of this steel pipe. It consists of concrete cast in and concrete and reinforcing bars embedded in this concrete. The thickened portion is one that protrudes on the inner and outer surfaces of the steel pipe, or on the inner surface side.
It only projects. The beam is joined to the thickened portion. By using the thickened steel pipe in this manner, the beam can be firmly joined without using a reinforcing material such as a diaphragm.
Therefore, it is easy to insert the reinforcing bars into the columns. Further, by constructing the steel-framed reinforced concrete structure using the thickened steel pipe in this way, it is possible to construct a frame-framed frame structure having excellent strength and easy to construct at low cost. Since the thickened portion is a portion integrally formed with the steel pipe by heating and compression, the thickened portion has high quality and high reliability, and the thickened portion can be formed easily and inexpensively as compared with centrifugal casting or the like. The reinforcing bars are assembled into a cage-shaped reinforcing bar assembly by a plurality of pillar main bars extending in the longitudinal direction of the pillar and hoops surrounding the pillar main bars.

When constructing this steel-framed reinforced concrete structure, a thickened steel pipe having a thickened portion by heating and compression in a part in the longitudinal direction is prepared and built. on the other hand,
A cage-shaped rebar assembly consisting of a plurality of column main bars and hoops surrounding these column main bars is prepared. This rebar assembly is inserted into the thickened steel pipe from above, and then concrete is placed in the thickened steel pipe. In this construction method, when the thickened steel pipes are connected vertically, each time the thickened steel pipes of the joints that are vertically joined are installed from below, the rebar assembly is added to the thickened steel pipes. It is preferable to insert the meat steel pipe from above. At the time of inserting the reinforcing bar assembly, it is preferable to attach a guide member to one of the hoops so as to make contact with the inner surface of the steel pipe, so that the insertion can be smoothly performed. It also helps to secure the covering thickness between the steel pipe and the reinforcing bar.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The first embodiment of the present invention is
This will be described with reference to FIGS. In this steel-framed reinforced concrete structure, a pillar 1 has a square-shaped thickened steel pipe 2 having a thickened portion 2a by heating and compression in a part in the longitudinal direction, concrete 3 cast in the steel pipe 2, and concrete 3 in the concrete 3. And a reinforcing steel bar 4 embedded in the inner wall of the steel plate, and a beam 5 (FIG. 2) of an H-shaped steel frame or the like is joined to the thickened portion 2a. The thickness-increased portion 2a of the thickness-increased steel pipe 2 is processed into a thickness-increased state by applying a compressive force in the axial direction to compressively deform while heating a part of the steel pipe as a raw material in the longitudinal direction by high frequency induction. The compressed and deformed portion is cooled with water or the like immediately after the deformation. In this example, the thickened portion 2a is projected to the inner and outer surfaces of the steel pipe 2, and both ends of the thickened portion 2a are tapered portions 2aa whose thickness gradually changes. Incidentally, it thickened portion 2a, as which projects only the outer surface side as shown in FIG. 6 (B), the of anything protruding only on the inner side as shown in FIG. 6 (C)
Of these, as shown in FIG. 6 (C), it may be projected only on the inner surface side .

As shown in FIG. 1B, the reinforcing bars 4 are assembled into a rectangular cylindrical cage-shaped reinforcing bar assembly 4A by a plurality of pillar main bars 4a and a hoop 4b surrounding the outer circumference of these pillar main bars 4a. Be done. The column main bars 4a are arranged at the four corners of a quadrangle having a size that allows for a predetermined covering thickness from the inner surface of the thickened steel pipe 2 and in the middle of each side. The column main bars 4a may be provided only at the four corners, or more columns may be provided depending on the diameter of the steel pipe 2 and the like. As shown in FIG. 3 (A), the thickened portion 2 a of the thickened steel pipe 2
Are provided at a plurality of positions according to the height position of the beam 5 which is a floor beam or the like on each floor, and a plurality of columns are vertically joined by a column joint 8. The end portion of the thickened steel pipe 2 joined by the column joint 8 and the end portion fixed on the foundation 7 are also the thickened portion 2b.

As shown in FIG. 2, the beam 5 has upper and lower flanges 5a joined to the thickened portion 2a of the thickened steel pipe 2 via a split tee 9. The split tee 9 has its head piece 9a joined to the thickened portion 2a by a shaft-shaped tightening tool 10, and the leg piece 9a.
b is joined to the upper and lower flanges 5a by bolts 11 such as high-strength bolts. In this example, a one-sided bolt is used as the shaft-shaped tightening tool 10, and is inserted through a bolt hole 12 formed in the thickened portion 2a and a bolt hole formed in the split tee 9. Here, the one-side bolt is a general term for a shaft-shaped tightening tool that is tightened from one end and can be tightened by plastically deforming the head portion 10a at the other end, and is also called a blind bolt. Instead of using the one side bolt, a screw hole 12A having a screw groove is provided in the thickened portion 2a as shown in FIG.
Alternatively, a nut may be fixed to the back surface and the split tee 9 may be joined with a normal bolt (not shown).
Further, without using the split tee 9, an end plate (not shown) is provided on the beam 5, and the end plate is joined to the thickened portion 2a of the thickened steel pipe 2 by the axial fastener 10. You can Further, as in the example of FIG.
Alternatively, the end of may be directly joined to the thickened portion 2a of the thickened steel pipe 2 by welding 13.

FIG. 4 shows a concrete example of the column joint 8 of FIG.
This column joint 8 includes thickened portions 2b of the upper and lower thickened steel pipes 2, 2.
The side plate 1 is overlaid on each side over the space 2b.
4 and the thickened portions 2b, 2b are joined by the shaft-like tightening tool 10. Although the one-sided bolt is used for the shaft-shaped tightening tool 10, a screw hole may be formed in the increased-thickness portion 2a and the bolt may be joined with a normal bolt. Note that the column joint 8 may be joined by the attachment plate 14 or the like without providing the thickened portion 2b and leaving the end portion of the thickened steel pipe 2 to have the same diameter as the general portion.

This steel frame reinforced concrete structure (see FIG.
In constructing (A)), the reinforcing bars 4 are assembled in advance into a cage-shaped reinforcing bar assembly 4A having a predetermined length as shown in FIG.
After the thickened steel pipe 2 is built, the thickened steel pipe 2 is inserted into the thickened steel pipe 2 from above and arranged at a predetermined position. Rebar assembly 4A is such that stacking a plurality respect one thickened steel pipe 2. For example, the reinforcing bar assembly 4A is set from the top in the manner of cast-in-place pile. In this case, as shown in FIG. 3 (B), the reinforcing bar 15 for temporary support is inserted under the hoop 4b near the upper end of the reinforcing bar assembly 4A, and the reinforcing bar 15 is utilized by the crane 20 to assemble the reinforcing bar. The solid 4A is hung down while being inserted into the thickened steel pipe 2a. The suspended rebar assembly 4A is supported by the temporary support rebar 15 on the upper end of the thickened steel pipe 2, and the upper rebar assembly 4A is suspended by the crane 20 and placed thereon in the same manner as described above. Upper and lower rebar assembly 4
After tying A with a tying wire 21 such as a numbering wire, a reinforcing bar for temporary support 1
5 is removed, and the upper rebar assembly 4A is further hung inside the thickened steel pipe 2. By using the temporary supporting reinforcing bars 15 in this manner, the upper and lower reinforcing bar assemblies 4A are stabilized during the work, and the bundling work and the like are facilitated. As in the example of FIG. 3, the thickened steel pipe 2
In the case of joining the thickened steel pipes 2 up and down, the reinforcing bar assembly 4A is inserted into the thickened steel pipes 2 after the thickened steel pipes 2 of the respective nodes, which are assembled in sequence from below, are erected. The pouring of the concrete 3 may be performed, for example, after the erection of the thickened steel pipe 2 up to the uppermost stage is completed, or every time the insertion of the reinforcing bar assembly 4A into the thickened steel pipe 2 of each node is finished. Is also good. In addition, as shown in FIGS. 1B and 2B, insertion guide members 16 may be attached to the reinforcing bar assembly 4A at a plurality of upper and lower positions on each side surface. The guide member 16 is a disc-shaped member having a hoop insertion hole in the center. By mounting the guide member 16 in this manner, the work of inserting the reinforcing bar assembly 4A into the thickened steel pipe 2 can be smoothly performed without being caught. Further, the guide member 16 also serves as a spacer that secures the covering thickness of the column main bar 4a. The guide member 16
Is not limited to a disc shape, and may be, for example, a curved reinforcing bar in a V shape.

According to this frame structure, the reinforcing bar 4 is thus
Since the column 1 having a steel-framed reinforced concrete structure is embedded in the concrete 3 in the thickened steel pipe 2, a strong yield strength can be obtained. In addition, since the thickened steel pipe 2 has the thickened portion 2a and the beam 5 is joined to the thickened steel pipe 2, a diaphragm or the like is not required, and the reinforcing bars 4 can be easily arranged in the steel pipe 2. Further, since the thickened portion 2a is formed integrally with the steel pipe 2 by heat compression,
It has high quality and high reliability, can be formed at the material stage, and has better productivity than when welding diaphragms. Moreover, since the thickened portion 2a is formed by heat compression,
It can be formed easily and cheaply as compared with centrifugal casting. As a method of constructing the reinforcing bar 4, when the reinforcing bar 4 is assembled in advance into the cage-shaped reinforcing bar assembly 4A as described above and sequentially inserted into the thickened steel pipe 2 from the top, the reinforcing bar 4 can be easily arranged. .

In each of the above examples, the thickened steel pipe 2 is a square steel pipe, but the thickened steel pipe 2 may be round. FIG. 7 shows an example in which the thickened steel pipe 2 has a round shape, and the end plate 17 of the steel beam 5 is formed into the thickened steel pipe 2.
The thickened portion 2a is joined by a shaft-shaped tightening tool 10. The end plate 17 has an arcuate curved surface along the outer diameter surface of the thickened portion 2, and is wider than the H-shaped steel portion of the steel beam 5, and also extends vertically. Although the one-sided bolt is used for the shaft-shaped tightening tool 10, a screw hole may be formed in the increased-thickness portion 2a and a normal bolt may be used. End plate 17
May be divided into upper and lower flanges 5a, 5a as in the example of FIG. In this example, the reinforcing bars 4 are formed by arranging the column main bars 4a on the circumference and providing the hoops 4b around them. Other configurations are the same as those in the example of FIG.

FIG. 9 is a reference proposal example, in which the upper and lower steel pipes 2 are provided.
A thick steel pipe 23 that serves as a beam joint is welded between Nos. 2 and 22. The thick steel pipe is used in the same manner as the thickened portion 2a of each of the above-described examples to join the beam 5. Assembling the reinforcing bar 4 into the reinforcing bar assembly 4A as shown in FIG. 1 (A), inserting the reinforcing bar 4 into the steel pipe 22, and filling the concrete 3 are the same as in the above-described examples. In this way, thick-walled steel pipe 2
Also when 3 is used, unlike the diaphragm or the like, the reinforcing bar 4 can be easily inserted. Further, it is possible to make up a solid structure by compensating for the loss of cross section due to the bolt holes through which the shaft-shaped fastener 10 is inserted.
In the example of FIG. 9, the thick-walled steel pipe 23 has a larger outer diameter and a smaller inner diameter than the upper and lower steel pipes 22.
3 may have the same outer diameter as the upper and lower steel pipes 22.

[0015]

The steel-framed reinforced concrete structure constructed according to the method of the present invention has a thickened steel pipe in which a column has a thickened portion by heating and compression in a part in the longitudinal direction, concrete cast in the steel pipe, and Since it is composed of a reinforcing bar embedded in concrete and a beam is joined to the thickened portion, it is possible to improve the yield strength, facilitate the construction, and reduce the cost. This method of the invention is assembled in a cage-shaped rebar assembly with a plurality of column main bars and hoops surrounding the column main bars, and the thickened steel pipe is inserted from the upper part after erection, so that the construction is easier. Oh Ru. To the rebars assembly hoop, when attaching the guide member contacting the inner surface of the steel pipe, when inserting the rebar assembly in thickening steel pipe, without hitting directly on the inner wall surface of the rebar thickening steel pipe, plug liable . In particular, when the thickened portion of the thickened steel pipe projects to the inner surface side, the projecting thickened portion can be easily inserted without being caught by the reinforcing bar.

[Brief description of drawings]

FIG. 1A is a partially cutaway perspective view of a column portion in a steel frame reinforced concrete structure using thickened steel pipe showing a first embodiment of the present invention, and FIG. 1B is a perspective view of a reinforcing bar assembly thereof.

FIG. 2 is a partial perspective view of the steel frame reinforced concrete structure,
(B) is a sectional view of the same portion.

FIG. 3A is a front view of the same steel-framed reinforced concrete structure, and FIGS. 3B and 3C are partial cross-sectional views showing a process of inserting the rebar assembly.

FIG. 4A is a cutaway front view of a column joint portion in the same structure, and FIG. 4B is a vertical sectional view of the same portion.

FIG. 5 is a partial perspective view of a steel frame reinforced concrete structure according to another embodiment of the present invention.

FIG. 6 is a partial cross-sectional view showing each example of the thickened portion of the thickened steel pipe.

FIG. 7 is a cutaway front view and a horizontal sectional view of a steel frame reinforced concrete structure according to still another embodiment of the present invention.

FIG. 8 is a front view of a steel reinforced concrete structure according to still another embodiment of the present invention.

FIG. 9 is a front view of a steel reinforced concrete structure according to a reference proposal example.

FIG. 10 is a perspective view of a conventional example.

[Explanation of symbols]

1 ... Column, 2 ... Thickened steel pipe, 2a ... Thickened part, 3 ... Concrete, 4 ... Reinforcing bar, 4a ... Main column bar, 4b ... Hoop, 4A ... Reinforcing bar assembly, 8 ... Beam joint

   ─────────────────────────────────────────────────── ─── Continued front page       (56) Reference JP-A-1-125437 (JP, A)                 JP 64-80638 (JP, A)                 Japanese Patent Laid-Open No. 7-11709 (JP, A)                 Japanese Patent Laid-Open No. 5-280096 (JP, A)                 Japanese Patent Publication 4-20457 (JP, B2)

Claims (3)

(57) [Claims] [Claim 1] have a thickened portion by heating and compressing a portion of the longitudinal direction, as the thickening portion projecting on the inner and outer surfaces of the steel pipe, or
Or a process of building a thickened steel pipe that protrudes only on the inner surface side as a column, and a process of preparing a cage-shaped rebar assembly consisting of a plurality of column main bars and hoops surrounding these column main bars, a plurality of the rebar assembly, one of the thickening
As stacking a plurality respect steel pipe, comprising the steps of Komu sequentially difference Ri by upwardly to the increase in meat steel pipe, after this, thickened steel pipe used steel comprising the steps of pouring the concrete into the increase in meat steel pipe Construction method of reinforced concrete structure. 2. The reinforcing bar assembly is inserted into a thickened steel pipe.
In the process, temporarily put it under the hoop near the top of the rebar assembly.
Insert the supporting rebar and use this temporary supporting rebar to
Inserting the reinforcing bar assembly into the thickened steel pipe with the lane
It is hung and this reinforced rebar assembly is used for temporary support.
The reinforcement is supported on the upper end of the thickened steel pipe, and the upper reinforcement
Assemble the assembly by hanging it with a crane as above.
After binding the upper and lower rebar assemblies with the binding wires,
And hang the upper rebar assembly inside the thickened steel pipe.
The method for constructing a steel-framed reinforced concrete structure using thickened steel pipe according to claim 1, wherein the steel frame is unloaded . 3. The method for constructing a steel-framed reinforced concrete structure using a thickened steel pipe according to claim 1 or 2, wherein a guide member that comes into contact with the inner surface of the steel pipe is attached to the hoop of the reinforcing bar assembly.