JP2005127056A - Joint structure of column and beam in rigid frame structural body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a join structure of a column and a beam capable of realizing construction by the column using a continuous steel pipe over a plurality of layers (stories) easily and providing force resistant against tensile force of a beam main reinforcing bar passing through the inside of the steel pipe securely. <P>SOLUTION: The steel pipe 11 being a constituent member of the column 1 having CFT structure is continuously formed in the vertical direction over at least a plurality of stories without dividing it. A plurality of openings 13 allowing insertion of a reinforcing bar 21a forming the beam main reinforcing bar of the beam 2 having reinforced concrete structure in play are provided on each side face by opposing mutually on both side faces of the steel pipe 11 which becomes a joint part of the column/beam at each story. The reinforcing bar 21a is fixed to a predetermined position while it passes through the openings 13 and the inside of the steel pipe 11. Opposing openings 13 are blocked by a fixation plate 30 attached to the reinforcing bar 21a. An inner side face of the fixation plate 30 is arranged in such a way that it adheres closely to concrete 12 filled in the inside of the steel pipe 11. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a joint structure of columns and beams in a ramen structure suitable for constructing a building such as a super high-rise apartment house or office building.

The structure filled with concrete inside the steel pipe is called a CFT (Concrete Filled Steel Tube) structure. 2. Description of the Related Art Conventionally, there is known a ramen structure in which a column is constituted by a CFT-structure steel pipe, and a steel structure (S structure) or steel concrete structure (SC structure) such as H-shaped steel is joined to the column. When the column is made of CFT, the method of joining the beam is structurally limited. Therefore, the beam is generally made of S or SC, and a method of joining a beam using a steel frame to a CFT column is common.
When joining such a beam including a steel frame and a CFT column, a diaphragm must be mounted in the steel pipe of the CFT (inner diaphragm), or a diaphragm must be attached to the outside of the steel pipe (outer diaphragm). In addition, since a steel frame is used for the beam, there is a problem that the amount of steel frame and the amount of processing of the steel frame increase and the cost increases.

As a structure in which a CFT column is combined with a reinforced concrete (RC) beam instead of a steel (S) or steel-concrete (SC) beam, the structure described in Patent Document 1 is disclosed. Are known. In Patent Document 1, “a pair of filled steel pipe concrete columns filled with concrete inside a steel pipe are arranged vertically with a beam of reinforced concrete structure interposed therebetween, and the reinforced concrete is interposed between these filled steel pipe concrete columns. A connecting bar is disposed through the beam, and a steel pipe end of the filled steel pipe concrete column is arranged spaced apart from the reinforced concrete beam, and the connecting bar is at least approximately the outer diameter of the steel pipe in the steel pipe. The column-to-beam joint structure characterized by being buried by a length twice as long. "
Further, Patent Document 2 states that “a structure of a column and a beam in a composite structure building composed of a filled steel tube concrete column filled with concrete in a column steel tube and a reinforced concrete beam. The coaxial steel pipe having the same diameter as the column steel pipe in the joint part, and securing a slit between the column steel pipe and the joint steel pipe, and passing the beam main bar through the slit, and The joint structure in a composite structure building is characterized in that a column main reinforcing bar is inserted into the joint steel pipe and the column steel pipe connected to the upper and lower sides thereof.

Japanese Examined Patent Publication No. 6-21467 JP 2000-273958 A

  The thing of the said patent document 1 is arrange | positioned up and down on both sides of the beam of a reinforced concrete structure with a filled steel pipe concrete pillar, and presupposes the use of the steel pipe divided | segmented for every layer (floor). Moreover, the thing of the said patent document 2 uses a column steel pipe and a jointed steel pipe as a component, In the same document, concrete methods, such as a method of arranging the jointed steel pipe of the same diameter as a column steel pipe, are concrete. The construction method is not disclosed. Moreover, the aspect of the slit between a column steel pipe and a jointed steel pipe is not specifically disclosed. Furthermore, although the above-mentioned Patent Document 1 discloses a beam main bar that passes through a slit provided between a column steel pipe and a jointed steel pipe having the same diameter, in this configuration, a beam that passes through this slit is generated during an earthquake. The force that resists the tensile force of the main bars may not be sufficient (especially when the column thickness is set relatively thin).

  The present invention has been made in consideration of the above-described prior art, and realizes construction by a column using a steel pipe that is continuous over a plurality of layers (floors), is easy to construct, and the main beam of the beam that penetrates the inside of the steel pipe It is an object of the present invention to provide a joint structure of columns and beams in a rigid frame structure that can reliably exert a force resisting a tensile force.

(1) Joined a CFT column and a reinforced concrete beam,
The steel pipes, which are the components of the columns, are continuously formed in the vertical direction without being divided over at least multiple floors, and the main beam bars are formed on both sides of the steel pipes that serve as joints for the columns and beams on each floor. A plurality of openings that can be freely inserted into each side, and drilled to face each other, the reinforcing bars fixed in place in a state of passing through the openings and the inside of the steel pipe,
It is a joint structure of columns and beams in a ramen structure.
(2) In the above-mentioned joint structure, the fixing plate attached to the reinforcing bar in a state in which the reinforcing bar is inserted closes the opposing openings, and the inner surface of the fixing plate is filled into the steel pipe. Arranged in close contact with the concrete.
(3) In the above-described joint structure, the fixing plate is attached so as to be held at a predetermined position by a nut positioned on the outer surface of the fixing plate and screwed into the reinforcing bar.
(4) In the above-described joint structure, a plurality of adjacent reinforcing bars are inserted and disposed in the opening.
(5) In the above-mentioned joint structure, the reinforcing bar penetrating the inside of the steel pipe has at least one end portion in the vicinity of the column / beam joint, and the beam main reinforcement and the machine forming the intermediate span portion of the beam It is joined by a type joint.
(6) In the above-described joint structure, the reinforcing bar penetrating the inside of the steel pipe is disposed so as to pass through a position avoiding the central portion of the planar shape of the steel pipe.

[Invention of Claim 1]
Since the steel pipe that is a component of the pillar is formed continuously in the vertical direction without being divided at least across multiple floors, the steel pipes that are continuous over multiple layers (floors) are used, and how to build the steel pipes with multiple layers as one section Efficient construction to perform is realized and easy to construct. Any method known as a method for placing concrete in a CFT column, a method for placing concrete by inserting a tremey tube from the upper part of the steel pipe, a method for placing concrete by press-fitting concrete from the lower part of the steel pipe, Can also be applied. Also, on both sides of the steel pipe that will be the joints of the pillars and beams on each floor, a plurality of openings that can be inserted freely into the reinforcing bars that form the beam main bars are drilled facing each other. Is fixed at a predetermined position while penetrating through the opening and the inside of the steel pipe, so that the reinforcing bar forming a part of the beam main reinforcement can be easily inserted through the opening of the steel pipe, so that the construction is easy. In addition, the fixing position of the reinforcing bar can be easily adjusted.

[Invention of Claim 2]
The fixing plate attached to the reinforcing bar in a state where the reinforcing bar is inserted closes each opening facing each other, and the inner side surface of the fixing plate is disposed in close contact with the concrete filled in the steel pipe. Thus, the opening can be easily closed, and a force resisting the tensile force of the beam main bar penetrating the inside of the steel pipe can be surely exhibited by the fixing plate, so that a joint structure having excellent proof stress can be obtained. This fixing plate also has a function of preventing leakage of concrete.

[Invention of Claim 3]
Since the fixing plate is held at a predetermined position by a nut positioned on the outer surface of the fixing plate and screwed into the reinforcing bar, the fixing plate can be easily and reliably disposed at the predetermined position.

[Invention of Claim 4]
Since the opening is arranged so that a plurality of adjacent reinforcing bars are inserted, the reinforcing bars that form part of the beam main reinforcement can be inserted through the opening of the steel pipe very easily. The construction is very easy and the manufacture of the steel pipe is also simple.

[Invention of Claim 5]
At least one end of the reinforcing bar that penetrates the inside of the steel pipe is joined by a mechanical joint to the beam main reinforcing bar that forms the middle span of the beam in the vicinity of the column / beam joint. Construction can be simple and reliable.

[Invention of Claim 6]
Since the rebar that penetrates the inside of the steel pipe is arranged so as to pass through a position that avoids the central part of the flat shape of the steel pipe, it is possible to secure a space for injecting concrete to be cast in the steel pipe, Easy to install. It is possible to place concrete of good quality by inserting a tremely pipe for placing concrete.

  Preferred embodiments of the present invention will be described with reference to the drawings. Note that the same reference numerals are used for the same elements in the drawings, and description thereof may be omitted as appropriate.

  FIG. 1 is a front view showing an outline of a framework of a rigid frame structure using a column-beam joint structure according to an embodiment, FIG. 2 is a front view of a column / beam joint, and FIG. FIG. 4 is a vertical cross-sectional view of a column / beam joint, and FIG. In FIG. 4, the concrete filled in the steel pipe 11 is not shown. 5 and 6 are perspective views illustrating the steel pipe 11 of the column 1.

As shown in FIG. 1, the pillar 1 is made of CFT (concrete-filled steel pipe), and is formed by filling concrete 12 into a linear steel pipe 11 extending in the vertical direction. A rigid frame structure is formed by rigidly joining the CFT column 1 and a linear reinforced concrete beam 2 extending in the horizontal direction.
As illustrated in FIG. 1 and FIGS. 5 and 6, the steel pipe 11 which is a constituent member of the pillar 1 is continuously formed in the vertical direction without being divided over at least a plurality of floors, and is formed in a single cylindrical shape. It is manufactured as a body. The planar shape of the column 1 (steel pipe 11) may be a circle or the like in addition to a rectangle. Inside the steel pipe 11, you may arrange | position a bending reinforcement bar in the perpendicular direction as needed. In addition, what was shown in FIG. 1 has shown the example which comprised the beam 2 by precast concrete structure.

Openings 13 into which rebars 21a forming part of the beam main bars 21 can be loosely inserted are opposed to each side surface on each side surface of the steel pipe 11 serving as a column / beam joint on each floor. (See FIGS. 2, 3, 4 etc.). “Forming a part of the beam main bar 21” means that it may form a part of the beam 21 even when viewed from the member. This means that it may be recognized.
In the example shown in FIGS. 1 to 5, the opening 13 is provided in two upper and lower stages at the joint with the beam 2. Reinforcing bars 21a that form part of the beam main bars 21 are loosely inserted into the openings 13 in the upper and lower two stages. Each opening 13 is sufficiently larger than the diameter of the inserted reinforcing bar 21a so that a gap is formed between the opening 13 and the reinforcing bar 21a through which the inside of the opening 13 and the steel pipe 11 is inserted, and sufficient play is obtained. Largely formed. In the example shown in the drawing, each opening 13 is formed in a horizontally long and substantially rectangular shape, and has a shape in which a plurality of adjacent reinforcing bars 21 a arranged in the horizontal direction in one beam 2 are inserted. For this reason, at the time of construction, insertion of the reinforcing bar 21a becomes easy, which is particularly preferable. The number of reinforcing bars 21a inserted through one opening 13 is not limited. The shape and size of the opening 13 can be set as necessary. Further, three or more openings 13 may be provided on each side surface of the steel pipe 11.
The openings 13 are formed in a vertically long, substantially rectangular shape, arranged in two rows on the left and right sides, and arranged in a vertical direction in one beam 2 so as to be inserted into a plurality of adjacent reinforcing bars 21a. Good (see FIG. 6). In addition, a plurality of reinforcing bars 21 a may be inserted into one opening 13 in the left and right and top and bottom directions.

  Moreover, it is preferable that the rebar 21a penetrating the inside of the steel pipe 11 is disposed so as to pass through a position avoiding the central portion of the planar shape of the steel pipe 11 as illustrated. Thereby, the space which inject | pours the concrete cast in a steel pipe can be ensured, and it is easy to construct. Even if the reinforcing bar 21a is disposed so as to pass through a position avoiding the corner in the planar shape of the steel pipe 11 so that a space into which the tremy tube can be inserted is formed in the corner of the planar shape of the steel pipe 11. Good. In addition, you may provide the cotter plate for shearing force transmission etc. by means, such as welding, on the surface of the steel pipe 11, for example between each opening part 13, the corner | angular part of the steel pipe 11, and other appropriate site | parts.

The opening 13 is blocked by the fixing plate 30. The fixing plate 30 is formed with a through hole 31 through which the reinforcing bar 21a can be inserted. Each opposing opening 13 is closed by the fixing plate 30 attached to the reinforcing bar 21a in a state where the reinforcing bar 21a is inserted through the through hole 31. For example, the fixing plate 30 is formed in a shape substantially similar to the opening 13, and has a size that fits in the opening 13 as shown in FIG. 7A, or the opening 13 as shown in FIG. 7B. It is disposed so as to close the opening 13 in such a manner that it is larger than the opening 13 and is placed on the edge of the opening 13. The fixing plate 30 is formed in a size smaller than the opening 13 and is disposed so as to be accommodated in the opening 13, thereby forming a clearance between the outer edge of the fixing plate 30 and the opening 13. The position of the reinforcing bar 21a can be adjusted within the range, and the fixing plate 13 can be prevented from protruding from the surface of the steel pipe 11, and only the nut 30 can be protruded (this can suppress the thickness of the fireproof coating). ). By making the fixing plate 30 larger than the opening 13 and placing it on the edge of the opening 13, it is possible to sufficiently secure the adjustment margin of the reinforcing bar 21 a.
7A and 7B show a mode in which one opening 13 is closed by one fixing plate 30 and a plurality of reinforcing bars 21a are inserted into one fixing plate 30. 13 may be closed by a plurality of fixing plates 30 (see FIGS. 7C and 7D). FIG. 7C shows a mode in which one fixing hole 30 is formed in one fixing plate 30 and one reinforcing bar 21a is inserted into one fixing plate 30. FIG. In this embodiment, a plurality of through holes 31 are formed in the fixing plate 30 and a plurality of reinforcing bars 21 a are inserted into the single fixing plate 30.
Since the steel pipe 11 is filled with the concrete 12, the inner surface of the fixing plate 30 is arranged in close contact with the filled concrete 12.

  2 to 4, the fixing plate 30 is mounted so as to be held at a predetermined position by a nut 32 that is positioned on the outer surface of the fixing plate 30 and screwed into the reinforcing bar 21 a. In this way, the reinforcing bars 21a that form part of the beam main bars 21 are securely fixed in a state of being inserted through the openings 13 of the steel pipe 11 of the column 1 and the inside of the steel pipe 11. The fixing plate 30 may be welded to the steel pipe 11 as necessary.

  The reinforcing bar 21a penetrating the inside of the steel pipe 11 is joined at least at one end thereof by a mechanical joint 25 and a beam main bar 21 forming a span intermediate part of the beam 2 in the vicinity of a column / beam joint. Are preferred. In the illustrated example, the reinforcing bars 21a penetrating the inside of the steel pipe 11 are joined at both ends by a mechanical joint 25 and a beam main bar 21 forming a span intermediate part of the beam 2 in the vicinity of the column / beam joint. An example is shown.

A mechanical mechanism in the above-described joint structure between the column and the beam will be described with reference to FIG. The description of the symbols in FIG. 8 is as follows. The nut 32 is not shown.
Mb1, Mb2: Bending moment of left and right beams
Mc1 and Mc2: Bending moments of lower and upper columns
Qc1, Qc2: Shear force of lower and upper columns
T1, T2: Tensile force acting on the beam-column joint by the beam main reinforcement
C1, C2: Compression force acting on the beam-column joint by the beam concrete part
F1, F2: Adhesion resistance around the beam main bar in the beam-column joint
B1, B2: Supporting resistance by fixing plate

The bending moments Mb1 and Mb2 of the beam act on the beam-column joint as tensile forces T1 and T2 of the beam main reinforcement and compression forces C1 and C2 of the compression side concrete at the beam end.
The tensile forces T1 and T2 of the beam main bars are transmitted as adhesion resistance forces F1 and F2 and bearing resistance forces B1 and B2 by the fixing plate in the column beam joint.
At the time of a small earthquake, adhesion resistance F1, F2 is the main resistance mechanism, but at the time of a large earthquake, it will resist as bearing resistance B1, B2. (If there is no fixing plate and there is no adhesion resistance of the main reinforcement in the column beam joint, a reaction force is applied at the compression concrete part of the opposite beam.)
Since this structure employs steel pipe concrete (CFT) construction, there is an advantage that the adhesion resistance F1 and F2 are larger than those of RC pillars due to the restraining effect of the steel pipe.
Furthermore, the bearing resistance forces B1 and B2 act with a spread of about 45 degrees as shown in the figure, and finally resist as a binding force of the steel pipe. In this structure, since the CFT structure having a very large restraining force is used, it is possible to exert larger bearing resistance B1 and B2. Therefore, this structure, which enables column CFT construction and RC beam construction, has the advantage of high seismic safety compared to RC main-frame building (both pillar and beam). In addition, the fixing plate can close the opening of the steel pipe, and the bearing resistance B1 and B2 by the fixing plate can surely exert the force that resists the tensile force of the beam main bar that penetrates the inside of the steel pipe. Excellent joint structure can be obtained.

Next, although the construction method of the joint structure of the pillar and beam which concerns on this invention is not specifically limited, The specific example is demonstrated with reference to FIGS. FIG. 9 is a perspective view illustrating the construction method, and FIG. 10 is a cross-sectional view of the column / beam joint, illustrating the construction method.
(1) First, the steel pipe 11 of the column 1 is erected (bending reinforcing bars may be disposed in the steel pipe 11 as necessary). Then, a precast concrete beam 2 is disposed at a predetermined position between the columns 1 and 1.
(2) Next, as shown in FIG. 10 (a), the reinforcing bar 21a is inserted from the opening 13, the inside of the steel pipe 11 is inserted, and the opening 13 on the opposite side is inserted.
(3) As shown in FIG.10 (b), the fixing plate 30, the nut 32, and the mechanical coupling 25 are attached from the both ends of the inserted reinforcing bar 21a, respectively.
(4) As shown in FIG. 10 (c), when passing a plurality of reinforcing bars 21a through one fixing plate, the inside of the steel pipe 11 is inserted into the fixing plate 30 already attached through the other reinforcing bars 21a. It is made to pass through the opening 13 on the side. Then, the nut 32 and the mechanical joint 25 are attached and installed at a predetermined position. The reinforcing bar 21 a and the beam main bar 21 of the beam 2 are connected by a mechanical joint 25.
(5) For the other reinforcing bars, the reinforcing bar 21a and the beam main reinforcing bar 21 of the beam 2 are connected by the mechanical joint 25 in the same procedure. The same procedure is used when the beam 2 crosses the column 1 in a cross shape.
(6) After that, the beam end and floor slab formwork are installed, floor reinforcement is performed, and concrete is poured from the hopper 40 into the steel pipe 11 of the column 1 and placed as shown in FIG. Further, concrete placement of beam ends and floor slab is performed (in FIG. 2, floor slab surfaces 50 and 51 are indicated by broken lines). In addition, the fireproof coating of the steel pipe 11 can be appropriately performed in the same manner as a normal CFT column.

In addition to the above method, a method as shown in FIG. 11 can also be applied. That is, as shown in FIG. 11A, after the steel pipe 11 of the column 1 is erected, the beam 2 (precast concrete structure) to be joined to one side across the steel pipe 11 is disposed at a predetermined position. A grout filling joint 27 is provided at the end of the beam 2.
Next, as shown in FIG. 11 (a), the beam 2 (precast concrete structure) is inserted from the other side of the steel pipe 11 and the beam main bar 22 protruding from the end of the steel pipe 11 is slightly opened from the opening 13 of the steel pipe 11. The main beam 22 is inserted into the steel pipe 11 and through the openings 13 and 13 (FIG. 11B).
Then, the end portion of the inserted beam main reinforcing bar 22 is connected to the grout filling type joint 27 provided at the end portion of the beam 2 disposed on one side (FIG. 11C).
According to the above method, the number of joints can be halved, and the beam main bar insertion operation can be reduced.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications and additions are possible within the scope of the present invention. In order to bend and reinforce steel pipes, reinforcing bars are provided at the corners of steel pipes, reinforcing plates are welded around the corners of the surface of steel pipes, or around openings, and at the joints of columns and beams. The plate thickness of the steel pipe can be increased.

It is a front view which shows the outline of the framework of the rigid frame structure comprised using the joint structure of the column and beam which concerns on an Example. It is a front view of the joint part of a pillar and a beam. It is a longitudinal cross-sectional view of the joint part of a pillar and a beam. It is a cross-sectional view of a joint part of a column / beam. 1 is a perspective view illustrating a steel pipe 11 of a column 1. 1 is a perspective view illustrating a steel pipe 11 of a column 1. 3 is a front view illustrating an embodiment of a fixing plate 30. FIG. It is explanatory drawing of the mechanical mechanism of this invention. It is a perspective view which explains a construction method and shows a construction mode. It explains a construction method and is a cross-sectional view of a column / beam joint. It is a top view which explains a construction method and shows a construction mode.

Explanation of symbols

1 Column 2 Beam 11 Steel Pipe 12 Concrete 13 Opening 21 Beam Reinforcement 21a Reinforcement 22 Beam Main Reinforcement 25 Mechanical Joint 30 Fixing Plate 32 Nut

Claims (6)

Joined CFT column and reinforced concrete beam,
The steel pipes, which are the components of the columns, are continuously formed in the vertical direction without being divided over at least multiple floors, and the main beam bars are formed on both sides of the steel pipes that serve as joints for the columns and beams on each floor. A plurality of openings that can be freely inserted into each side, and drilled to face each other, the reinforcing bars fixed in place in a state of passing through the openings and the inside of the steel pipe,
Joint structure of columns and beams in a ramen structure. The fixing plate attached to the reinforcing bar is inserted in the state where the reinforcing bar is inserted, and the openings facing each other are closed, and the inner side surface of the fixing plate is disposed in close contact with the concrete filled in the steel pipe. ,
The joint structure of a column and a beam in the rigid frame structure according to claim 1. The fixing plate is attached so as to be held at a predetermined position by a nut positioned on the outer surface of the fixing plate and screwed into the reinforcing bar.
The joint structure of a column and a beam in the rigid frame structure according to claim 2. In the opening, a plurality of adjacent reinforcing bars are inserted and arranged.
The joint structure of the column and the beam in the ramen structure according to any one of claims 1 to 3.   The reinforcing bar penetrating the inside of the steel pipe has at least one end thereof joined by a mechanical joint with a beam main bar forming a middle span portion of the beam in the vicinity of a column / beam joint. Item 5. The joint structure of columns and beams in the ramen structure according to any one of Items 1 to 4. The reinforcing bar penetrating the inside of the steel pipe is disposed so as to pass through a position avoiding the central portion in the planar shape of the steel pipe.
The joint structure of the column and the beam in the ramen structure according to any one of claims 1 to 5.

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