JPH0463936B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a column-to-beam joint structure in a part of a building structure where the columns and beams are connected, such as filled steel pipe concrete.

[Conventional technology]

Conventionally, this type of column-to-beam joint structure has been constructed using a filled steel pipe concrete column made by pouring concrete inside a steel pipe, and an auxiliary part to maintain rigidity at the joint between the column and beam. It is known that a stiffener ring is joined by welding, and a beam is joined to this stiffener ring.

[Problem that the invention seeks to solve]

However, in the above-mentioned conventional filled steel pipe concrete column and beam joint structure, the beam is simply welded to the outer peripheral surface of the steel pipe, and the stress transmission between the steel pipe and concrete depends on the adhesive strength of the joint. . Therefore, the shearing force of the beam is transmitted as axial stress from the weld between the beam and the steel pipe to the steel pipe, and part of the axial stress transmitted to the steel pipe is transferred from the attachment surface of the steel pipe and concrete to the axis of the concrete. The force is also transmitted to the concrete. In addition, the moment of the beam is transmitted from the weld between the beam and the steel pipe to the steel pipe as in-plane shear stress, and part of the in-plane shear stress transmitted to the steel pipe is transferred from the steel pipe and concrete attachment surface to the concrete as shear stress. communicated.

In this way, in the conventional column-to-beam joint structure, the force transmission path from the beam to the column twists and turns, and the transmission force is transmitted to the internal concrete from the bonding surface of the steel pipe and concrete. It depends on the adhesion strength of the bonding surface between the steel pipe and concrete.

Therefore, the steel pipes of the columns are subjected to axial stress, in-plane shear stress, and circumferential stress from the concrete, and are likely to become plastic due to the Mises yield condition.

Therefore, for columns made of filled steel pipe concrete, it is no longer expected that the compressive strength of concrete due to the confining effect of the steel pipe will increase as much as when the axial stress and in-plane shear stress are very small. As a result, the design safety factor had to be set to an excessively high value, resulting in the cross-sectional area of the columns being larger than necessary, and the wall thickness of the steel pipes being thicker than necessary.

This invention was made in view of the above circumstances, and introduces mechanical resistance into the joint structure of columns and beams,
By ensuring that the concrete section of the column remains flat, the transmission of forces from the beam to the concrete part of the column is smooth, direct and clear, and the axial and shear stresses applied to the steel pipe part of the column are reduced. The aim is to reduce the amount of heat and enhance the confining effect provided by steel pipes.

[Means for solving problems]

The present invention relates to a joint structure between a column and a beam of filled steel pipe concrete, in which the steel pipe is included in the concrete filled inside the steel pipe at the part where the steel pipe and the beam are connected, and both ends thereof are One or more webs are provided to be joined to the inner wall of the steel pipe, and one or more supports are included in the concrete at predetermined locations on the web and run along a plane substantially orthogonal to the axis of the steel pipe. A pressure plate is attached.

In this invention, the proof strength can be increased by arranging reinforcing bars or introducing prestress into the concrete filled in the steel pipe.

〔Example〕

The present invention will be explained below with reference to FIGS. 1 to 12. Figures 1 and 2 are the first diagrams of this invention.
FIG. 3 and FIG. 4 are diagrams showing a second embodiment of the present invention. FIGS. 5 and 6 show the third embodiment of the present invention, and FIGS. 7 and 8 show the third embodiment of the present invention.
The figures show the fourth embodiment of the present invention, FIGS. 9 and 10.
The figures show the fifth embodiment of the present invention.
FIG. 2 is a diagram showing a sixth embodiment of the present invention.
All of these examples show joint structures of filled steel pipe concrete columns and beams.

First, referring to FIGS. 1 and 2, reference numeral A in these figures indicates a column made of filled steel pipe concrete. Filled steel pipe concrete column (hereinafter abbreviated as "column") A includes a steel pipe 1 that also serves as a formwork,
Webs 2a inside the steel pipe 1 and perpendicular to each other,
2b, 2c, a bearing plate 3 attached to the lower end of the webs 2a, 2b, 2c, and the webs 2a, 2b,
2c and a bearing plate 3 and concrete 4 filled in the steel pipe 1. web 2b,
2c is welded perpendicularly to the web 2a, and both ends thereof are welded to the inner wall of the steel pipe 1. A column A is provided at the lower end of the webs 2a, 2b, 2c.
A disk-shaped bearing plate 3 is welded along a plane substantially perpendicular to the axis of the bearing plate 3 . Beams B, C, D, and E are welded to the outer peripheral surface of column A so as to be perpendicular to each other on the same horizontal plane. For beams B, C, D, and E,
Webs B1, C1, D of long plates arranged vertically
1 and E1 are provided, the webs B1 and D1 are connected to the web 2a via the steel pipe 1, and the webs C1 and E1 are connected to the webs 2b and 2 via the steel pipe 1.
The structure is connected to c.

In this configuration, mainly web B of beams B and D
1, the shearing force acting on D1 is transmitted to the web 2a within the steel pipe 1 via the steel pipe 1. The shearing force transmitted to the web 2a is transmitted through the bearing plate 3 to the concrete 4 containing them as its axial force.

In this way, the shearing force of the beams B and D is transmitted from the web 2a connected to the webs B1 and D1 via the steel pipe 1 to the bearing plate 3, that is, through the mechanical transmission path, and is directly applied to the concrete 4. It is transmitted to Similarly, the shearing force acting mainly on the webs C1, E1 of the beams C, E is transmitted to the webs 2b, 3c via the steel pipe 1, and further directly transmitted from the bearing plate 3 to the concrete 4 as its axial force. In this way, steel pipe 1
The stress in the axial direction disappears because it no longer receives much shearing force from the beams B to E, and when the Mises yield condition is applied, the tolerance for the stress in the circumferential direction generated in the steel pipe 1 due to the transverse strain of the concrete 4 is reduced. The value increases, and the confining effect given to the concrete 4 can be enhanced. Therefore, the joint structure between the column A and the beams B to E is guaranteed to have a much higher compressive strength than the conventional structure, and the design safety factor can be appropriately set. Further, since the cross-sectional area of the column A is often determined by the cross-section of the joint between the column and the beam, it is possible to reduce the cross-sectional area of the column A as a result. or
It becomes possible to reduce the wall thickness of the steel pipe 1.

Next, a second embodiment shown in FIGS. 3 and 4 will be described. In Figures 3 and 4, Figure 1,
The same elements as those of the first embodiment shown in FIG. 2 are given the same reference numerals. (Hereafter, the third
(For the sixth embodiment as well, the same elements as those of the first and second embodiments are designated by the same reference numerals.) In these figures, the reference numeral A1 is a pillar. Column A1 is steel pipe 1, which also serves as formwork, and steel pipe 1.
Webs 2a, 2b, which are inside the web and are orthogonal to each other.
2c, bearing plates 3a, 3b, 3c, 3d attached to the lower ends of webs 2a, 2b, 2c, webs 2a, 2b, 2c, bearing plates 3a, 3b, 3
c, 3d, and concrete 4 filled in a steel pipe 1. The webs 2b and 2c are welded perpendicularly to the web 2a, and both ends thereof are welded to the inner wall of the steel pipe 1.
The lower surfaces of the ends of the webs 2a, 2b, 2c are provided with pillars A.
Disc-shaped bearing pressure plates 3a, 3b, 3c, and 3d are welded along a plane substantially perpendicular to the axis of the first embodiment.
Beams B, C, D, and E are welded to the outer peripheral surface of the column A1 so as to be orthogonal to each other on the same plane.
Beams B, C, D, and E have web B placed vertically.
1, C1, D1, and E1, webs B1 and D1 are connected to web 2a via steel pipe 1, and webs C1 and E1 are connected to webs 2b and 2c via steel pipe 1. It is said that

In this configuration, the shearing force acting on the beams B, D is transmitted to the webs 2a, 2b, 2c via the steel pipe 1, as in the case of the first embodiment, and is further transmitted to the bearing plates 3a, 3b, 3c, 3d. Concrete 4
It is transmitted as axial force at the navel. Further, the moment acting on the beams B and D is transmitted to the web 2a and the steel pipe 2 as in-plane shear stress. The in-plane shear stress transmitted to the web 2a is held flat by the bearing plates 3a and 3c, and is transmitted to the concrete 4 as shear stress. In this way, the shearing force acting on the beams B and D is transmitted through the steel pipe 1 to the webs B1 and
From the web 2a connected to D1 to the bearing plates 3a, 3
b, 3c, and 3d, that is, directly transmitted to the concrete 4 by a mechanical transmission path. Furthermore, most of the moment acting on the beams B and D is transmitted as in-plane stress in the web 2a, which is further maintained in plane by the mechanical resistance of the bearing plates 3a and 3c, and transmitted to the concrete 4 as shear stress. . Similarly, the shearing force acting on beams C and E is applied to web 2, which is connected to webs C1 and E1 via steel pipe 1.
The moment that is directly transmitted from b, 2c to the concrete 4 through the bearing plates 3a, 3b, 3c, 3d, and that acts on the beams C, E is mostly transmitted as in-plane shear stress of the webs 2b, 2c. Furthermore, the surface is held flat by the mechanical resistance of the bearing plates 3b and 3d, and is transmitted to the concrete 4 as shear stress.

In this way, the steel pipe 1 is no longer subjected to much shearing force from the beams B to E, so that the stress in the axial direction is reduced. Further, since the steel pipe 1 transmits most of the moment from the beams B to E to the concrete 4, the in-plane shear stress is reduced. Therefore, when the Mises yield condition is applied, the allowable value for the stress in the circumferential direction generated in the steel pipe 1 due to the transverse strain of the concrete 4 increases, and the confining effect given to the concrete 4 can be enhanced. Therefore, this joint structure between column A1 and beams B to E ensures a much higher compressive strength than the conventional one, and it is possible to appropriately set the design safety factor. . Further, since the cross-sectional area of the column A1 is often determined by the cross-section of the joint between the column and the beam, it is possible to reduce the cross-sectional area of the column A1 as a result. Alternatively, it is possible to reduce the wall thickness of the steel pipe 1.
Furthermore, in this column-beam joint structure, the shear force and moment load cross section of the beam can be freely adjusted by changing the area and position of the web and bearing plate.

Next, the embodiment of FIG. 3 shown in FIGS. 5 and 6 will be described. In these figures, reference numeral A2 is a column made of reinforced concrete. Column A2 is Column A
Reinforcing bars 5, 5... are arranged along the circumferential direction inside. In such a joint structure between the column A2 and the beams B to E, the column A2 has the same function and effect as the first embodiment shown in FIGS. The material can have a large proof strength.

Next, a fourth embodiment shown in FIGS. 7 and 8 will be described. In these figures, reference numeral A3 is a column made of reinforced concrete. Column A3 is column A
1, reinforcing bars 5, 5, . . . are arranged along the circumferential direction. In such a joint structure between the column A3 and the beams B to E, the column A3 has the same functions and effects as the second embodiment shown in FIGS. It can be made with a large proof strength.

Next, a fifth embodiment shown in FIGS. 9 and 10 will be described. In these figures, reference numeral A4 is a column made of prestressed concrete. Column A4 has sheathed pipes 6, 6, ... placed in the column A along the circumferential direction, passes the prestressed steel material through the sheathed pipes 6, 6, ..., and connects the prestressed steel material after the concrete 4 has hardened. It gives tension. Therefore, even if the building is subjected to an earthquake and an overturning moment is generated and a tensile stress is applied to the column A4, the actually generated tensile force will be the value obtained by subtracting the prestress force. That is, in this joint structure of column A4 and beams B to E, it has the same function and effect as the first embodiment described above, and column A4 can have a larger member strength than column A. .

Next, a sixth embodiment shown in FIGS. 11 and 12 will be described. In these figures, the symbol A5
is a column containing prestressed concrete. This column A5 has sheath tubes 6, 6, ... arranged in the column A1 along the circumferential direction, and sheath tubes 6, 6, ...
A prestressing steel material is passed through ... and tension is applied to the prestressing steel material after the concrete 4 has hardened. Therefore, pillar A5 has the same function and effect as pillar A4. In addition, this joint structure between the column A5 and the beams B to E has the same functions and effects as the second embodiment described above, and the column A5 can have a larger member strength than the column A1. .

In each of the above examples, since the column-beam joint structure can reduce the cross-sectional area of the column,
Can be used as a pillar for flexible structures.

〔Effect of the invention〕

As mentioned above, the present invention provides one or more pieces of concrete that are contained in the concrete filled inside the steel pipe at the portion where the steel pipe and the beam are connected, and whose both ends are joined to the inner wall of the steel pipe. The structure consists of two webs, and one or more bearing plates are installed at predetermined locations on these webs along a plane that is almost orthogonal to the axis of the steel pipe, ensuring that the concrete cross section of the column remains flat. The von Mises reliably and directly transmits most of the shear force and moment of the beam to the concrete cross section of the column, reducing the axial stress and in-plane shear stress applied to the steel pipe section of the column. By applying the yield condition of It is possible to reduce the step area and the wall thickness of the steel pipe.

[Brief explanation of the drawing]

1 to 12 are diagrams showing embodiments of the present invention. Figures 1 and 2 are the first diagrams of this invention.
FIG. 1 is a partial sectional view of a main part of the invention, FIG. 2 is a sectional view of FIG. 1, and FIG.
4 are diagrams showing a second embodiment of the present invention, FIG. 3 is a partial cross-sectional view of the main part of the present invention, FIG. 4 is a cross-sectional view of FIG. 3, FIG. 6 is a diagram showing a third embodiment of the present invention, FIG. 5 is a partial sectional view of the main part of the invention, FIG. 6 is a sectional view of FIG. 5, FIG. The drawings are diagrams showing a fourth embodiment of the present invention, in which Fig. 7 is a partial sectional view of the main part of the invention, Fig. 8 is a sectional view of Fig. 7, Fig. 9, and Fig. 10.
The drawings show a fifth embodiment of the present invention, in which Fig. 9 is a partial sectional view of the main part of the invention, Fig. 10 is a sectional view of Fig. 9, and Figs. 11 and 12 are FIG. 11 is a partial cross-sectional view of a main part of the present invention, and FIG. 12 is a cross-sectional view of FIG. 11. A, A1, A2, A3, A4, A5... Filled steel pipe concrete column, 1... Steel pipe, 2a, 2b,
2c...web, 3, 3a, 3b, 3c, 3d...
...Bearing plate, 4...Concrete, B, C, D, E
...beam, B1, C1, D1, E1...web.

Claims (1)

[Scope of Claims] 1. A joint structure between a column and a beam made of filled steel pipe concrete, wherein the steel pipe is joined to the beam and the steel pipe is joined to the concrete filled inside the steel pipe. , and one or more webs having both ends joined to the inner wall of the steel pipe are provided, and one or more webs are provided at a predetermined location of this web along a plane included in the concrete and substantially perpendicular to the axis of the steel pipe. A column-to-beam joint structure having a bearing plate or a plurality of bearing plates. 2. The column-to-beam joint structure having a bearing plate according to claim 1, wherein reinforcing bars are arranged in the concrete filled in the steel pipe. 3. A column-to-beam joint structure having a bearing plate according to claim 1, wherein prestress is introduced into the concrete filled in the steel pipe.