JP2002266433A - Joint structure for joining steel-pipe concrete column to flat slab - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simple joint structure of excellent design for securely joining the concrete columns of upper and lower stories to a flat slab. SOLUTION: The joint structure includes a steel-pipe concrete column 1 separated into a lower steel pipe 2a for the lower story and an upper steel pipe 2b for the upper story, with the lower portion of the upper steel pipe 2b inserted into the lower steel pipe 2a and concrete 4 placed therein; and a flat slab 5 formed of reinforced concrete provided on the top of the lower steel pipe 2a. A bearing plate 3 having a greater outside diameter than the lower steel pipe 2a is provided on the outer periphery of the lower portion of the upper steel pipe 2b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a steel pipe concrete column constructed by filling concrete inside a steel pipe,
The present invention relates to a joint structure with a reinforced concrete flat slab.

[0002]

2. Description of the Related Art Conventionally, a flat slab structure is a construction method mainly used in reinforced concrete construction. In this case, the pillar is also made of reinforced concrete, and as shown in FIG. 4, a support part 13 called a capital is provided at a joint between the pillar 11 and the floor slab 12. in this way,
When both the pillar 11 and the floor slab 12 are made of reinforced concrete, the pillar 11 and the floor slab 12 can be easily integrated by fixing the reinforcing steel of the floor slab 12 inside the pillar 11.

[0003] On the other hand, steel pipe concrete columns, which have become widespread in recent years, have a structure in which concrete is filled in a steel pipe having a circular or square cross section, and one of its features is that it can support a high axial force. . Reinforced concrete flat slabs are also often used when the load on the floor is large, and combining steel tube concrete columns and reinforced concrete flat slabs (hereinafter simply referred to as flat slabs) is a reasonable construction method. You can say that.

[0004] In this case, how to join the steel pipe concrete column and the flat slab is a problem. An invention relating to this point is disclosed in Japanese Patent Application Laid-Open No. Hei 8-109695. There is a structure. In this joint structure, as shown in FIGS. 5 and 6, a supporting steel plate 17 and a rib 18 are welded to a steel tube concrete column 15 filled with concrete 16 so as to support a vertical load of a flat slab 19. those (prior art 1).

Another example is disclosed in Japanese Patent Application Laid-Open No. 6-8141.
No. 8 discloses an invention related to a method for joining a steel pipe concrete column and a flat slab. As shown in FIG. 7, the present invention includes, in the lower and upper portions of the joining position of the flat slab 19 on the outer peripheral portion of the steel pipe concrete column 15,
The steel receivers 20a and 20b are fixed by welding or the like, respectively, and the load of the flat slab 19 is supported by the receivers 20a and 20b (prior art 2).

Further, in the joint structure of a steel pipe column and a flat slab disclosed in Japanese Patent Application Laid-Open No. 6-88392, as shown in FIG. In the slab 19, reinforcing bars 23 are joined on both upper and lower sides in the longitudinal direction,
5A is provided with a reinforcing iron plate 22 penetrating therethrough (prior art 3).

Further, as shown in FIG. 9, the joint structure disclosed in Japanese Patent Application Laid-Open No. 2000-320057 has upper and lower steel pipe concrete columns 15b and 15c separated from each other above and below the capital 24, and the steel pipe concrete columns 15b and 15c are separated from each other. 15c and the flat slab 19 are connected to the concrete columns 1
Reinforcing bars 25, 26, 27 penetrating the insides of 5b, 15c and the capital 24 are integrated with concrete 16 (prior art 4).

[0008]

Generally, in order to rigidly join a steel pipe concrete column and a flat slab,
In order to transmit the bending moment of the flat slab to the concrete column made of steel pipe, the joint portion between them has a considerably complicated structure like the joint structure shown in Prior Art 3. On the other hand, a method of connecting the steel pipe concrete column and the flat slab to a simple pin connection and separately providing a resistance element such as an earthquake-resistant wall against a horizontal force such as an earthquake can be considered. The joining structures of the prior arts 1 and 2 correspond to this.

However, when such a design principle is adopted, the steel pipe concrete column only supports the vertical load from the flat slab, so the steel pipe concrete column on the lower floor needs to support a larger floor load than the upper floor. Considering the economic design, it is desirable that the section of the steel pipe concrete column on the upper floor is smaller than that on the lower floor. Although the publications of the prior arts 1 and 2 do not mention such a problem, as shown in FIGS. 10 and 11, the diameter of the upper column 15 d is reduced at the joint between the steel pipe concrete column and the flat slab. The method is general. In this case, it is necessary to separately manufacture a steel pipe 15f having a tapered joint portion, and it is necessary to weld the upper and lower portions of the tapered steel pipe 15f to the steel pipe concrete columns 15d and 15e. There was a problem.
In these joint structures, the flat slab 1
Since the hardware 17, 20a, and 20b supporting the metal 9 are exposed, it is necessary to separately provide a fireproof coating in order to maintain a vertical load in the event of a fire.

In the joint structure of the prior art 4, the steel pipe forming the steel pipe concrete column 15b on the upper floor and the steel pipe forming the steel pipe concrete column 15c on the lower floor are separated.
Although it is relatively easy to change the diameter of the steel pipe concrete column, there is a problem that the capital 24 protrudes, which is not preferable in terms of design, and that the arrangement of reinforcing bars is complicated.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has a simple structure, and can reliably connect a steel slab concrete column and a flat slab on the upper and lower floors, and has an excellent design. It is an object of the present invention to provide a joint structure between a steel pipe concrete column and a flat slab.

[0012]

(1) A joint structure between a steel pipe concrete column and a flat slab according to the present invention is divided into a lower steel pipe and an upper steel pipe on a lower floor and an upper floor, and an upper steel pipe is provided in the lower steel pipe. Having a steel pipe concrete column into which concrete is poured by inserting the lower part thereof, and a reinforced concrete flat slab provided on the upper part of the lower steel pipe,
A support plate having an outer diameter larger than an outer diameter of the lower steel pipe is provided on a lower outer periphery of the upper steel pipe.

(2) A projecting member projecting inward is provided at the upper end of the lower steel pipe of (1), and a projecting member projecting outward is provided at the lower end of the upper steel pipe. (3) A stiffening member is provided between the upper steel pipe of (1) or (2) and the supporting plate to connect them. (4) The supporting plate of the upper steel pipe of any of the above (1), (2) or (3) was installed above the lower surface of the flat slab.

[0014]

[First Embodiment] FIG. 1 is a schematic sectional view of a joint structure between a steel pipe concrete column and a flat slab according to a first embodiment of the present invention. In the figure, 1
Is a steel pipe concrete column (hereinafter referred to as a steel pipe column) in which concrete 4 is filled in a steel pipe, and 5 is a flat slab made of reinforced concrete (rebar is omitted in the figure). Lower steel pipe 2a on lower floor
A flat slab 5 is provided between the lower steel pipe 2a and the upper steel pipe 2b on the upper floor. In the following description, the lower steel pipe 2a filled with concrete 4 is used for the lower steel pipe column 1a and the upper steel pipe 2b is used for the upper steel pipe 2b. It is called steel pipe column 1b.

Upper steel pipe 2b constituting upper steel pipe column 1b
Is a lower steel pipe 2a whose outer diameter constitutes a lower steel pipe column 1a.
A donut-shaped supporting plate 3 made of a steel plate is fixed to the outer periphery of the lower portion by welding or the like, and the outer diameter thereof is formed larger than the outer diameter of the lower steel pipe 2a. ing. In addition, the support plate 3 is the upper steel pipe 2
Alternatively, a plurality of steel plates may be attached to the outer periphery of the upper steel pipe 2b at appropriate intervals.

Next, an example of the construction procedure of the present embodiment configured as described above will be described. First, the lower steel pipe 2a in which the reinforcing steel of the flat slab 5 is arranged around the upper end portion
The upper steel pipe 2b is inserted from above into the upper steel pipe 2b concentrically with the lower steel pipe 2a, installed so that the supporting plate 3 is located above the lower surface of the flat slab 5, and fixed at that position using a fixing bracket or the like. . At this time, the support plate 3 projects outward from the outer periphery of the lower steel pipe 2 a and is located in the flat slab 5. Then, concrete 4 is poured into the lower steel pipe 2 a and the upper surface of the flat slab 5 including the support plate 3.

After the concrete 4 is solidified, the upper steel pipe on the upper floor is installed on the upper steel pipe 2b as described above, and the concrete 4 is poured into the upper steel pipe 2b and the flat slab on the upper floor. The upper steel pipe column 1b including the column 1a, the flat slab 5, and the support plate 3 is integrally joined. The above-described construction procedure is an example, and can be changed as appropriate.

According to the present embodiment, at the joint between the steel pipe column 1 and the flat slab 5, the upper steel pipe column 1b is embedded in the upper part of the lower steel pipe column 1a, and the flat slab is formed in the lower part of the upper steel column 1b. Since the supporting plate 3 for supporting the vertical load of 5 is provided, there is no need to provide a capital portion for increasing the thickness of the flat slab, and the lower steel pipe column 1a, the upper steel pipe column 1b and the flat slab 5 are joined with a simple structure. can do.

[Second Embodiment] FIG. 2 is a schematic explanatory view of a joint structure according to a second embodiment of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. In this embodiment, the upper end of the lower steel pipe 2a is
A donut-shaped projecting member 6 whose outer diameter is substantially equal to the outer diameter of the lower steel pipe 2a and whose inner diameter is smaller than the inner diameter of the lower steel pipe 2a is attached by welding or the like while protruding inward, and is attached to the lower end of the upper steel pipe 2b. A protruding member 7 having an inner diameter substantially equal to the inner diameter of the upper steel pipe 2a, an outer diameter larger than the outer diameter of the upper steel pipe 2b, and smaller than an inner diameter of the protruding member 6 provided on the lower steel pipe 2a.
Are attached by welding or the like so as to protrude outward.

The construction procedure and effects of the present embodiment are almost the same as those of the first embodiment, except that the upper end of the lower steel pipe 2a and the lower end of the upper steel pipe 2b inserted into the lower steel pipe 2a project. Since the members 6 and 7 are provided, the bending deformation between the upper steel pipe column 1b and the lower steel pipe column 1a is prevented by the projecting members 6,7.
Since the compressive force of the concrete 4 between them is restrained, the joining strength between the lower steel pipe column 1a and the upper steel pipe column 1b can be improved. In addition, although the case where the donut-shaped projecting members 6 and 7 are provided over the entire circumference at the upper end of the lower steel pipe 2a and the lower end of the upper steel pipe 2b is shown, the projecting members 6 and 7 are divided into a plurality of parts. They may be attached at predetermined intervals.

[Third Embodiment] FIG. 3 is a schematic explanatory view of a joint structure according to a third embodiment of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. In the present embodiment, a plurality of stiffening members 8 are joined between the upper steel pipe 2b and the support plate 3 by welding or the like.

The construction procedure and effects of the present embodiment are almost the same as those of the first embodiment, except that a stiffening member 8 is joined between the upper steel pipe 2b and the supporting plate 3, and the supporting plate 3 Since the received vertical load is transmitted to the upper steel pipe column 1b via the stiffening member 8, the ability to support the vertical load can be improved.

In each of the above-described embodiments, the case where the bearing plate 3 provided on the upper steel pipe 2b is disposed in the flat slab 5 above the lower surface of the flat slab 5 is described. Since the shear strength is designed with a thickness higher than the support plate 3, the flat slab 5 can be made thinner by disposing the support plate 3 at the lower surface of the flat slab 5. But,
In this case, since it is necessary to apply a fireproof coating to the exposed surface of the support plate 3, if the support plate 3 is positioned in the flat slab 5 slightly above the lower surface of the flat slab 5, the support plate 3 is covered with concrete. Therefore, there is no need to apply a fireproof coating.

Although the embodiments of the present invention have been described above, each of the embodiments may be implemented independently, or the embodiments may be combined as appropriate.

[0025]

Next, an example of the joint structure according to the first embodiment will be described. As the lower steel pipe 2a, a round steel pipe having an outer diameter of 600 mm and a wall thickness of 12 mm was used, and as the upper steel pipe 2b, a round steel pipe having an outer diameter of 400 mm and a wall thickness of 9 mm was used. Also,
A supporting plate 3 was formed by joining a donut-shaped steel plate having an outer diameter of 900 mm and a thickness of 16 mm to the outer periphery 650 mm above the lower end of the upper steel pipe 2 b. And the lower steel pipe 2a in which the reinforcing steel of the flat slab 5 is arranged around the upper part
The upper steel pipe 2b was inserted into the center of the lower steel pipe 2 and the supporting plate 3 was positioned 50 mm above the upper end of the lower steel pipe 2a, and was fixed at that position. At this time, the protruding length of the support plate 3 from the outer periphery of the lower steel pipe 2a was 150 mm.

In this state, concrete 4 was poured into the lower steel pipe 2a and the upper surface of the flat slab 5. In addition,
The thickness of the flat slab 5 is about 300 mm. After the concrete 4 was hardened, the concrete 4 was poured into the upper steel pipe 2b. As a result, the upper steel pipe 2b is integrated with the lower steel pipe column 1a, the supporting plate 3 and the flat slab 5 by the concrete 4 cast therein, and the lower steel pipe column 1
a, the upper steel pipe column 1b and the flat slab 5 were firmly joined.

[0027]

According to the first aspect of the present invention, there is provided a steel pipe concrete column in which lower and upper floors are separated into a lower steel pipe and an upper steel pipe, and the lower part of the upper steel pipe is inserted into the lower steel pipe and concrete is poured. And a flat slab made of reinforced concrete provided on the upper part of the lower steel pipe, and a supporting plate having an outer diameter larger than the outer diameter of the lower steel pipe is provided on the outer periphery of the lower part of the upper steel pipe, so that the steel pipes need to be welded to each other. The lower steel pipe, upper steel pipe and flat slab can be joined with a simple structure.

According to a second aspect of the present invention, an inwardly projecting member is provided at an upper end of the lower steel pipe of the first aspect,
The projecting members that protrude outward are provided at the lower end of the upper steel pipe. The compressive force of the concrete between these projecting members restrains the bending deformation between the upper steel pipe column and the lower steel pipe column, and the joint strength between them is Can be improved.

According to a third aspect of the present invention, a stiffening member for connecting the upper steel pipe and the supporting plate is provided between the upper steel pipe and the supporting plate, and a vertical load received by the supporting plate is transmitted through the stiffening member. Since the power is transmitted to the upper steel column, the ability to support a vertical load can be improved.

According to a fourth aspect of the present invention, the supporting plate of the upper steel pipe according to any one of the first to third aspects is installed above the lower surface of the flat slab, and the supporting plate is covered with concrete. The coating can be omitted.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of a joint structure according to a first embodiment of the present invention.

FIG. 2 is a schematic sectional view of a joint structure according to a second embodiment of the present invention.

FIG. 3 is a schematic sectional view of a joint structure according to Embodiment 3 of the present invention.

FIG. 4 is an explanatory view of a conventional joint structure between a reinforced concrete column and a floor slab.

FIG. 5 is an explanatory diagram of Conventional Technique 1.

FIG. 6 is a plan view of FIG. 5;

FIG. 7 is an explanatory diagram of Conventional Technique 2.

FIG. 8 is an explanatory diagram of Conventional Technique 3.

FIG. 9 is an explanatory diagram of Conventional Technique 4.

FIG. 10 is an explanatory diagram of another example of the related art.

FIG. 11 is an explanatory diagram of another example of the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Steel pipe concrete pillar (steel pipe pillar) 1a Lower steel pipe pillar 1b Upper steel pipe pillar 2a Lower steel pipe 2b Upper steel pipe 3 Bearing plate 4 Concrete 5 Flat slab 6,7 Projection member 8 Stiffening member

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hiromi Shimokawa 1-2-2 Marunouchi, Chiyoda-ku, Tokyo F-term in Nihon Kokan Co., Ltd. (reference) 2E163 FA02 FF17

Claims (4)

[Claims] 1. A steel pipe concrete column into which a lower steel pipe and an upper steel pipe are separated on a lower floor and an upper floor, and a lower part of the upper steel pipe is inserted into the lower steel pipe and concrete is cast therein. And a flat slab made of reinforced concrete, wherein a supporting plate having an outer diameter larger than the outer diameter of the lower steel pipe is provided on a lower outer periphery of the upper steel pipe. Joint structure. 2. The concrete column according to claim 1, further comprising a projecting member projecting inward at an upper end of the lower steel pipe and a projecting member projecting outward at a lower end of the upper steel pipe. Joint structure with flat slab. 3. A joint structure between a steel pipe concrete column and a flat slab according to claim 1, wherein a stiffening member for connecting the upper steel pipe and the support plate is provided between the upper steel pipe and the supporting plate. 4. The supporting plate of the upper steel pipe is installed above the lower surface of the flat slab.
Or the joining structure of the steel pipe concrete column and flat slab in any one of 3.