JPH11264190A - Connection structure of filled steel tube concrete column - Google Patents

Abstract

(57) [Summary] [PROBLEMS] It is possible to join a beam of RC structure to a concrete column filled with steel pipe, and as a result, it is possible to reduce the cost as compared with the case of joining a beam of SRC structure. The present invention provides a connection structure for a concrete column filled with steel pipe. SOLUTION: A column cap 1a of a filled steel pipe concrete column 1
In the above, the main reinforcement 25 is arranged such that its lower end 25a is embedded in the filled concrete 16 and its upper end 25b projects from the column capital 1a, and the concrete C is struck on the upper end 25b of the main reinforcement 25. Set up and frame 2
7, and the beam 23 was joined to the frame 27.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint structure of a concrete column filled with steel pipe for joining a concrete column and a beam formed by filling concrete inside a steel pipe.

[0002]

2. Description of the Related Art As is well known, filled steel tubular concrete columns have been applied to various structures because they have a large compressive strength and are easy to construct compared to ordinary RC structures. ing. FIG. 4: is a figure which shows the outline of the viaduct 2 to which the filled steel pipe concrete column 1 was applied. The filled steel pipe concrete column 1 is erected between the underground beam 4 buried in the ground G and the SRC upper beam 7 supporting the bridge girder 5 at the viaduct 2. FIG. 5 is a view showing a structure of a connection 8 between the filled steel pipe concrete column 1 and the upper beam 7. As shown in the figure, a ring-shaped steel plate 10 is provided on a column head 1a of a filled steel pipe concrete column 1,
Above the steel plate 10, there is provided a steel pipe 12 having substantially the same height as the girder 11 constituting the upper beam 7. Furthermore, the upper part of the steel pipe 12 is closed by a disk-shaped steel plate 13. The girder 11 of the upper beam 7 has a configuration in which the upper flange 11a and the lower flange 11b are welded to the steel plates 13 and 10, and the girder 11 and the steel pipe 12, The concrete 8 is cast and the connection 8 is formed.

[0003]

However, in the case where the connection 8 is formed as described above, there is a problem that it is not possible to cope with an attempt to reduce the cost by making the upper beam 7 an RC structure. In addition, since the above-mentioned connection 8 has a relatively rigid structure, the first yield point in the viaduct 2 is not the connection 8 but the filled steel pipe concrete column 1 and the ground when a strong earthquake occurs. Occurs sometimes at the joint with the center beam 4. In this case, check the earthquake
The repair work had to be performed underground, making the work very cumbersome. Further, when the connection 8 is formed as described above, the filled concrete 16 filled inside the filled steel pipe concrete column 1 (see FIG. 5).
However, there was a concern that the vertical load of the upper beam 7 would flow to the steel pipe 17 (see FIG. 5) as a result of creep deformation and contraction over a long period of time.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and enables a beam having an RC structure to be joined to a concrete column filled with steel pipe, thereby reducing costs as compared with the case of using an SRC beam. In addition, inspection and repair work in the event of an earthquake is easy, and furthermore, if the secular change occurs, the filled steel pipe concrete Its purpose is to provide a connection structure.

[0005]

Means for Solving the Problems To solve the above problems, the present invention employs the following means. That is,
The joint structure of the filled steel pipe concrete column according to claim 1,
A joint structure of a filled steel pipe concrete column for joining a beam to a filled steel pipe concrete column having filled concrete inside a steel pipe, wherein at an end of the filled steel pipe concrete column, a main reinforcement is provided. One end is embedded in the filled concrete, and the other end is provided so as to protrude from the end. Concrete is cast on the other end side of the main reinforcing bar to form a skeleton, and the skeleton is formed. Characterized in that the beam is joined to the second member.

[0006] Because of such a structure, in this connection structure, the filled steel pipe concrete column and the beam of the RC structure can be joined.

[0007] A joint structure of a concrete column filled with a steel pipe according to a second aspect is the joint structure of a concrete column filled with a steel pipe according to the first aspect, wherein the main reinforcing bar has one end at an inner peripheral surface of the steel pipe. , Or provided close to the inner peripheral surface while being separated from the inner peripheral surface.

[0008] Because of such a configuration, in this connection structure, a stable structure can be obtained by maximally separating the spaces between the main bars existing in the same plane.

A third aspect of the present invention is a joint structure for a concrete column filled with steel pipe according to the first or second aspect, wherein the steel pipe and the beam are vertically separated from each other. It is characterized by being provided.

[0010] With such a configuration, in this connection structure, even if the concrete filled in the steel pipe contracts and deforms, the load from the beam is not directly transmitted to the steel pipe.

According to a fourth aspect of the present invention, there is provided a joint structure of a concrete column filled with a steel pipe, wherein the outer peripheral surface of the frame is located between the steel pipe and the beam. Is characterized by being covered with a caulking material.

With this structure, the durability of the main reinforcement is not impaired in this connection structure even when the main reinforcement has little concrete covering.

According to a fifth aspect of the present invention, there is provided a joint structure for a filled steel pipe concrete column, wherein the outer periphery of the frame is located between the steel pipe and the beam. The surface is covered with a plate-shaped member, and the plate-shaped member is embedded in the filled concrete in a state where an end on the steel pipe side is in contact with an inner peripheral surface of the steel pipe. .

[0014] With this configuration, in this joint structure, the plate-like member can be used as a formwork for forming the frame.

[0015]

An embodiment of the present invention will be described below with reference to the drawings. In this embodiment, the same components as those of the above-described conventional technology are denoted by the same reference numerals, and description thereof is omitted. FIG. 1 is a diagram schematically showing an embodiment of the present invention.
Indicates a connection structure. The connection structure 21 is formed by joining the filled steel pipe concrete column 1 and the beams 23 having the RC structure.

As shown in the drawing, the connection structure 21 is provided with main bars 25,... And band bars 26,. The main bars 25 are arranged so that the lower end 25a is buried in the filling concrete 16 of the column head 1a of the concrete-filled steel tubular column 1, and the upper end 25b projects upward from the column head 1a. Have been. Further, the stirrup 26 is disposed with respect to the upper end portion 25b, and the upper end portion 25b and the streak 2
Concrete body 6 is cast on concrete 6 to form skeleton 27. Note that a large diameter (for example, D41) is used for the main bar 25. Also, the upper end 25 of the main bar 25
The c-head is provided with a T-head bar 28 in order to facilitate the arrangement of reinforcing bars without hooks.

On the other hand, the beam 23 is formed by placing concrete C on the beam main bars 30,... And stirrups 31,. The beam main bar 30 has a tip 30
a is embedded in the skeleton 27, whereby the beam 23 and the skeleton 27 are joined. Further, the beam 23 is joined to the frame 27 at a position separated from the upper end 17 a of the steel pipe 17. Also, the beam 23 and the steel pipe 17
Outer peripheral surface 27a of frame 27 located between upper end 17a
Is covered with a caulking material 32 made of a material such as an acrylic resin or a urethane resin. FIG. 2 is a diagram showing a cross section taken along the line AA in FIG. 1. As shown in FIG.
, Or in a state of being separated from the inner peripheral surface 17a (for example, approximately 2 cm or less).

In the connection structure 21 described above, a RC frame skeleton 27 is provided on the column head 1a of the filled steel tubular concrete column 1, and the beams 23 are joined to the frame 27. Even if the beam has an RC structure such as the beam 23, it is possible to satisfactorily join the concrete column 1 with the filled steel pipe.
There is no need to use a C-shaped structure, and cost can be reduced. Further, since the RC frame 27 having a lower yield strength than the filled steel tube concrete column 1 is interposed between the filled steel tube concrete column 1 and the beam 23 as described above,
Can be intentionally set as the first yield point at the time of the earthquake, thereby avoiding damage occurring at the joint between the underground beam and the filled steel tubular concrete column 1. In this case, inspection and repair work after the structure is actually damaged by the earthquake can be facilitated.

In the connection structure 21, the main reinforcement 2
Are arranged along the inner peripheral surface 17a of the steel pipe 17, so that the spacing between the main reinforcements 25,...
It is possible to support the beam 23 as stably as possible via the 7. In general, when the cross-sectional force of a filled steel tubular concrete column is changed according to the reinforced concrete section, structurally, the amount of the reinforcing bar must be increased as the position of the reinforcing bar is set inside the cross section. As a result, the number of reinforcing bars is often too large to arrange the reinforcing bars. However, if the main reinforcing bars 25 are inscribed in the inner peripheral surface 17a of the steel pipe 17 as described above, the number of the main reinforcing bars 25,. Thus, the arrangement work can be facilitated and the cost can be reduced.

Further, in the joint structure 21, since the beam 23 and the upper end 17a of the steel pipe 17 are separated from each other, even if the filled concrete 16 contracts due to aging, the load on the beam 23 is reduced. Does not flow directly to the steel pipe 17, and therefore the safety is high even when the service period is long.

Further, in the connection structure 21, the frame 2
7 is covered with the caulking material 32, so that the main bars 25,.
Are inscribed in the steel pipe 27, so that even if the covering thickness of the concrete C becomes small, rust of the main reinforcing bars 25,... Can be prevented and the durability thereof can be secured.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and other embodiments may be adopted according to structural and construction requirements. it can.

For example, in the above embodiment, the main muscle 2
By placing the steel frame at the position surrounded by 5, ...
The frame 27 may have an SRC structure. Further, the connection structure 21 may be provided on a column base of the filled steel pipe concrete column 1.

Further, a connection structure 35 as shown in FIG. 3 may be provided instead of the connection structure 21 in the above embodiment. This connection structure 35 is different from the connection structure 21 shown in FIG.
For a, a thin iron plate (plate-like member) instead of the caulking material 32
37 is provided. The thin iron plate 37 has a lower end 37a disposed along the inner peripheral surface 17a of the steel pipe 17, and thereby serves to protect the skeleton 27 and the main reinforcement 25 embedded in the skeleton 27.

Further, the thin iron plate 37 can be used as a substitute for a formwork when forming the frame 27, and can be used as a discarded formwork after the concrete C is cast. Thereby, the work of dismantling the formwork can be omitted and the construction work can be facilitated. Furthermore, as this thin iron plate 37,
For example, if a thin plate such as a galvanized steel plate is used, processing and installation are easy.

[0026]

As described above, according to the first aspect of the present invention, there is provided a joint structure for a concrete-filled steel tubular column having a RC structure or an SRC structure provided at an end of the concrete-filled steel tubular column. Since the beam and the column are configured to be joined, it is possible to favorably join the filled steel pipe concrete column and the beam having the RC structure.
The beam does not need to be made of S or SRC, and the cost can be reduced. In addition, since the skeleton installed in this way has a lower yield strength than the filled steel tube concrete column, this part can be intentionally set as the first yield point at the time of the earthquake. If it is provided on the capital, etc., damage to other parts (for example, underground parts) can be avoided. In this case, inspection and inspection after the structure is actually damaged
Repair work can be facilitated.

In the joint structure of the concrete column filled with steel pipe according to the second aspect, since the main reinforcing bars are arranged along the inner peripheral surface of the steel pipe forming the column, the spacing between the main reinforcing bars in the same plane is made as far as possible. As a result, the filled steel pipe concrete column can support the beam as stably as possible via the skeleton. In addition, it is possible to reduce the number of main bars, thereby facilitating bar arrangement work, and reduce costs.

According to the third aspect of the present invention, since the beam and the steel pipe are separated from each other, even if the filled concrete inside the steel pipe shrinks due to aging, the load of the beam can be reduced. Does not flow directly into the steel pipe, and therefore is highly safe even when the service period is long.

[0029] In the joint structure of the filled steel pipe concrete column according to claim 4, since the outer peripheral surface of the skeleton is covered with the caulking material, the main reinforcement is arranged in contact with the steel pipe,
As a result, even if the thickness of the concrete covering the main reinforcement becomes small, rust or the like generated on the main reinforcement can be prevented, and durability can be ensured.

According to a fifth aspect of the present invention, there is provided a joint structure of a filled steel pipe concrete column, wherein a plate-like member is arranged on an outer peripheral surface of a frame, and an end of the plate-like member on the steel pipe side is inscribed in the steel pipe. Since it is buried in a pillar, it is possible to use this plate-like member as a discarded formwork when forming a skeleton,
Thereby, the work of dismantling the formwork can be omitted and the construction work can be facilitated.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view of a joint structure of a concrete-filled steel tube concrete column schematically showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA in FIG.

FIG. 3 is an elevational sectional view of a joint structure of a filled steel pipe concrete column showing another embodiment of the present invention.

FIG. 4 is an external perspective view of a structure to which the conventional technique of the present invention is applied.

5 is a vertical sectional view showing a connection of a filled steel pipe concrete column in the structure shown in FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Filled steel pipe concrete pillar 16 Filled concrete 17 Steel pipe 21, 35 Connection structure 23 Beam 25 Main reinforcement 25a Lower end 25b Upper end 27 Frame 32 Caulking material 37 Thin iron plate (plate-like member) 37a Lower end C concrete

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Takanori Sato 1-3-2 Shibaura, Minato-ku, Tokyo Shimizu Corporation

Claims (5)

[Claims] 1. A joint structure of a filled steel pipe concrete column for joining a beam to a filled steel pipe concrete column having filled concrete inside a steel pipe, wherein an end portion of the filled steel pipe concrete column is provided. ,
One end is embedded in the filled concrete, and the other end is provided so as to protrude from the end, and concrete is cast on the other end of the main bar to form a skeleton, and A connection structure for a filled steel pipe concrete column, wherein the beam is joined to a skeleton. 2. The joint structure of a concrete column filled with steel pipe according to claim 1, wherein the main reinforcing bar has one end thereof in contact with an inner peripheral surface of the steel pipe or is separated from the inner peripheral surface. A connection structure for a filled steel pipe concrete column, wherein the connection structure is provided so as to be close to each other. 3. The concrete structure of a concrete column filled with steel pipe according to claim 1, wherein the steel pipe and the beam are vertically separated from each other. Pillar connection structure. 4. The joint structure of a concrete column filled with steel pipes according to claim 3, wherein an outer peripheral surface of the skeleton located between the steel pipe and the beam is covered with a caulking material. Filled steel pipe concrete column connection structure. 5. The joint structure of a filled steel pipe concrete column according to claim 3, wherein an outer peripheral surface of the frame located between the steel pipe and the beam is covered with a plate-like member. A joint structure for a concrete column of a filled steel pipe, characterized in that the member is buried in the filled concrete in a state where an end on the steel pipe side is in contact with an inner peripheral surface of the steel pipe.