JPH0610380B2 - Joint structure of filled steel pipe concrete column and brace - Google Patents

Description

TECHNICAL FIELD The present invention relates to a joint structure between a filled steel pipe concrete column (column of a filled steel pipe concrete structure) and a brace (belly).

"Conventional technology" Filled steel pipe concrete columns are columns for construction that are filled with concrete in the steel pipe, and are compressed in the axial direction by the confined effect of the steel pipe (the effect of tightening the concrete inside). It is intended to improve the column strength against the load.

Conventionally, as a joint structure between such a column and a so-called brace, for example, as shown in FIG. 6, a joint member 23 is projected by welding or the like on the surface of a filled steel pipe concrete column 21, that is, the outer surface of a steel pipe 22. A structure is known in which the end of the brace 24 is bolted to the joint member 23.

"Problems to be Solved by the Invention" By the way, although the brace resists a tensile force in an oblique direction and improves the proof stress against the horizontal force of the building frame composed of columns and beams, When a tensile force acts on the brace 24 to the right in FIG. 6 in the joint structure,
There is a problem that tensile force acts on the steel pipe 22 in the circumferential direction (the direction of the arrow in FIG. 6). That is, when the steel pipe 22 receives a tensile force in the circumferential direction, not only is it difficult to obtain the confining effect, but also the steel pipe 22 and the concrete 25 inside thereof may be separated.

The present invention has been made in view of the above circumstances, and an object thereof is to prevent the steel pipe from receiving a tensile force in the circumferential direction due to the brace, and to improve the column strength of the filled steel pipe concrete column by the confined effect. The purpose of the present invention is to provide a joint structure between a steel column and a brace for holding steel pipes.

[Means for Solving the Problems] In order to achieve such an object, the joint structure of the present invention is provided with a tensile force transmission member that traverses a steel pipe for a column inside a steel pipe for a column that constitutes a filled steel pipe concrete column. And
An end of a brace is connected to one end of the tensile force transmitting member, the tensile force transmitting member is located at least on the extension line of the brace, and at least the side to which the brace is connected in the transverse direction. Is characterized in that the opposite end is fixed to the steel pipe.

[Operation] According to the joint structure of the present invention, when a tensile force acts on the brace, the tensile force is transmitted to the pipe wall of the filled steel pipe concrete column on the side opposite to the brace joint side via the tensile force transmitting member. . Therefore, the bearing force is transmitted to the concrete without receiving the tensile force in the circumferential direction of the steel pipe.

[Examples] Hereinafter, the present invention will be described based on examples shown in the drawings.

FIG. 1 shows a building frame to which a joint structure according to an embodiment of the present invention is applied. In the figure, reference numeral 1.1 is a filled steel pipe concrete column. These filled steel tube concrete columns 1
A plurality of steel beams 2.2 are bridged between 1 and
Braces 3.3 are stretched so as to draw a diagonal line of a quadrangle formed by the filled steel tube concrete columns 1 and the steel beam 2.

The filled steel pipe concrete column 1 is a column steel pipe (hereinafter simply referred to as a steel pipe) 4 filled with concrete 5, and a separation layer (for example, paraffin, grease, asphalt, or , A layer 6 made of plastic or the like is interposed, and both 4 and 5 are in an unbonded state (non-attached state). Further, the filled steel tubular concrete column 1 has a beam joint 7 at the joint with the steel beam 2, a brace joint 8 at the joint with the brace 3, and a beam joint 7 and a brace joint. A deformation absorbing portion 9 is provided at a position spaced from the mouth portion 8 in the axial direction.

As shown in FIG. 2, the beam joint portion 7 projects outwardly in the radial direction from the outer surface of the steel pipe 4, and is connected to the end of the steel beam 2 by bolts. A pressure bearing member (for example, two steel plates assembled in a cross shape) 11 that crosses the inside in the radial direction. Further, as shown in FIG. 3, the brace joint portion 8 is provided with a mounting member (for example, a steel plate) 12 projecting from the outer surface of the steel pipe 4 on the side where the braces are joined and bolted to the end of the brace 3, and the mounting member 12. It is composed of a tensile force transmission member (for example, a steel plate) 13 which is continuous with the member 12 via the pipe wall of the steel pipe 4 and traverses the inside of the steel pipe 4 in the radial direction. As can be seen from FIG. 1, the pulling force transmitting member 13 exists at least corresponding to the extension line of the brace 3. However, in the present embodiment, the tensile force transmission member 13 is integrated with the pressure bearing member 11 from the portion where it collides with the pressure bearing member 11, and both ends in the transverse direction (the radial direction) thereof are steel pipes. It is welded and fixed to the inner surface of No. 4. Further, the deformation absorbing portion 9 is a portion in which a large number of elongated holes 14 ... That penetrate the steel wall of the steel pipe 4 are arranged.
As shown in FIG. 1, each of these elongated holes 14 extends in the circumferential direction of the steel pipe 4 and is arranged in a plurality of rows along the circumferential direction. Further, in the adjacent rows, they are offset from each other in the circumferential direction. Are arranged.

In the joint structure configured as described above, when a tensile force acts on the brace 3 in the right direction in FIG. 3 (the arrow direction in FIG. 1), the tensile force is applied from the mounting member 12 to the pipe wall of the steel pipe 4 and the tensile force transmitting member. It is transmitted to the tube wall on the opposite side (the tube wall at the left end in FIG. 3) via 13. Therefore, the bearing force in the arrow direction is transmitted to the concrete 5 without receiving the tensile force in the circumferential direction of the steel pipe 4.

As a result, the confined effect of the steel pipe 4 is sufficiently exerted, and the strength of the filled steel pipe concrete column against a compressive load can be reliably retained. Moreover, since the tensile force transmitting member 13 is located at least on the extension line of the brace 3, the tensile force of the tensile force transmitting brace 3 is
The above action is effectively exerted by being directly transmitted to the pipe wall of the steel pipe 4 opposite to the side where the braces 3 are provided.

By the way, the filled steel pipe concrete pillar 1 of the present embodiment has an excellent confined effect by the action of the separation layer 6 and the deformation absorbing portion 9 as compared with the case where the steel pipe and the concrete are in an adhered state. That is, when the shearing force of the steel beam 2 acts as a compressive load in the filled steel pipe concrete column 1 in the axial direction, the steel pipe 4 and the concrete 5 are displaced by the action of the separation layer 6 while being mutually displaced in the axial direction. That is, in the steel pipe 4, the deformation absorbing portion 9 absorbs most of the strain that should occur in the entire steel pipe 4 due to the axial deformation of the elongated holes 14 ... And the strain amount and stress in the axial direction in the other portions. Becomes zero. On the other hand, the concrete 5 receives a compressive load from the steel beam 2 via the pressure bearing member 11, and substantially displaces by supporting the compressive load alone. Therefore, the steel pipe 4 reliably resists the radial outward displacement of the concrete 5 at this time, and tightens inward in the radial direction.

On the other hand, FIGS. 4 and 5 show another embodiment of the present invention. In this drawing, a long through hole 15 is vertically provided on the pipe wall of the steel pipe 4 on the brake joint side, and a tensile force transmission member 16 is inserted into the steel pipe 4 through the through hole 15. Also in this embodiment, the outer tensile force transmission member 16 is provided corresponding to the extension line of the brace 3. One end of the pulling force transmitting member 16 on the insertion side is welded and fixed to the inner surface of the steel pipe 4, and the other end thereof is struck outside the steel pipe 4 and bolted to the brace 3. Such a joint structure is particularly applicable to a bonded type filled steel pipe concrete column in which the steel pipe 4 and the concrete 5 are attached to each other.
It has an effect of preventing the peeling of the concrete 5 with the concrete.

Also in this case, since the tensile force transmitting portion 16 exists corresponding to the extension line of the brace 3, the tensile force transmitting member 16 is provided.
The tensile force is directly transmitted to the pipe wall of the steel pipe 4 on the side opposite to the side on which the braces 3 are provided, without applying an extra force such as bending.

In the above embodiment, the steel pipe 4 having a circular cross section is described as an example, but a square steel pipe may be used. Further, the filled steel pipe concrete pillar 1 may be a bond type. Furthermore, in the other embodiment, the tensile force transmission member 16 may be welded and fixed around the through hole 15. Furthermore, the deformation absorbing portion 9 has a long hole 14
However, the steel pipe 4 may be bent outward in the radial direction to form a bulged portion.

"Effect of the invention" As described above, the joint structure of the filled steel pipe concrete column and the brace according to the present invention has a tensile force transmission member that traverses the steel pipe for a column inside the steel pipe for a column that constitutes the filled steel pipe concrete column. Is provided and the end of the brace is connected to one end of the tensile force couple member, the tensile force transmitting member is located at least on the extension line of the brace, and at least the brace in the transverse direction thereof. Since the end portion on the side opposite to the side to which is connected is fixed to the steel pipe, the following excellent effects are exhibited.

When a tensile force acts on the brace, this tensile force is transmitted to the pipe wall on the side opposite to the brace joint side of the filled steel pipe concrete column via the tensile force transmitting member. Therefore, since the supporting force is transmitted to the concrete without receiving the tensile force in the circumferential direction of the steel pipe, the confined effect of the steel pipe is sufficiently exerted, and the strength of the filled steel pipe concrete column against the compressive load is reliably retained. be able to.

Moreover, since the tensile force transmitting member is arranged so as to be positioned at least on the extension line of the brace, the tensile force from the brace can be effectively transmitted to the pipe wall of the steel pipe on the side opposite to the side where the brace is provided. Will be more effectively exhibited.

When the filled steel pipe concrete column is of the bond type, peeling between the steel pipe and the concrete therein is prevented, which largely contributes to the improvement of the durability of the building frame.

[Brief description of drawings]

1 is a schematic front view showing a building frame to which an embodiment of the present invention is applied, FIG. 2 is a view taken along the line II-II in FIG. 1, and FIG. 3 is a line III-III in FIG. Fig. 4 is a vertical sectional view showing another embodiment of the present invention, Fig. 5 is a sectional view taken along the line V-V in Fig. 4, and Fig. 6 is a transverse sectional view showing a conventional joining structure. is there. 1 ... Filled steel tube concrete columns, 2, ... Steel beams, 3 ...
… Braces, 4 …… Steel pipes, 5 …… Concrete, 6 ……
Separation layer, 8 ... Brace joint part, 12 ... Mounting member, 13,1
6 ... tensile force transmission member, 15 ... through hole.

Claims (1)

[Claims] 1. A joint structure of a filled steel pipe concrete column and a brace, wherein concrete is filled in the inside of a steel pipe for columns, wherein a tensile force transmission member that traverses the steel pipe for columns is provided inside the steel pipe for columns. The pulling force transmitting member is provided with one end of the brace connected to one end of the brace, the pulling force transmitting member is located on an extension line of the brace, and at least the brace in the transverse direction is connected. A joint structure of a filled steel pipe concrete column and a brace, characterized in that an end portion on the side opposite to the open side is fixed to the steel pipe.