JPH06240814A - Square steel tube for column - Google Patents

Abstract

PURPOSE:To obviate an excess reinforcement at a central part by a method wherein square steel tubes in specified thickness are inserted into bores on the upper and the lower side of a square steel tube in specified thickness, and the thickness on the upper and the lower end is made thereby to be thicker than the thickness on the central part of the tube. CONSTITUTION:Square steel tubes 2 and 3, approximately in 4.5mm in the thickness (b), are inserted into the bore of a square steel tube 1 for a column, approximately in 4.5mm in the thickness (a) and in L in the axial length, from its upper and lower end up to points respectively one-third from the upper and the lower end, making the thickness (b) on the upper and the lower end thicker, and each of the inserted tubes is connected by spot welding. Then, the steel tube 1 for column is used in a structural body in a rigid frame structure made up of columns and beams in framed rigid joint structure. Thereby, resistance against bending load stress is made stronger than central part in end parts where horizontal load is applied more, and deflexion is hardly produced by horizontal load caused by external force due to such as earthquakes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a square steel pipe for a pillar used as a pillar of a unit structure.

[0002]

2. Description of the Related Art As a unit structure of a unit building,
There is a rigid frame structure in which columns and beams made of square steel pipe are rigidly framed in a box shape.

According to this, since the nodes of the columns and beams are rigid, a large external force due to an earthquake or typhoon is easily propagated to the foundation without being concentrated in one place, and the strength of the entire building is improved. Is being pursued.

Generally, when designing a structure of a building from the viewpoint of strength, it is necessary to consider external force by dividing it into a horizontal component and a vertical component. In this case, the vertical component mainly takes into account the buckling stress of the column, while the horizontal component mainly takes into account the bending stress of the column.

Therefore, the second moment of area of the column is
This is a major factor in designing the strength of the structure.

By the way, the form and scale of the building are individual, and in a unit building produced by industrial production,
In addition to the reinforced structure as a uniform basic design, additional reinforced structures for each product are often required.

In such a case, the wall thickness of the square steel pipe is calculated according to the external force acting on the column in the horizontal direction, and the square steel pipe having a uniform thickness is adopted. In addition, as a supplementary reinforcement of the connecting portion of the rectangular steel pipe, for example, the actual open sho 59-4
In some cases, the measures shown in Japanese Patent No. 3531 are taken.

[0008]

However, in the case of the above-mentioned rigid frame structure, the bending moment acting on the intermediate portion of the column is much smaller than the bending moment acting on the end portion thereof, so in other words, Since the point of action of the bending moment is in the central part, if the above reinforcing structure is adopted as it is, the wall thickness of the square steel pipe is increased evenly, and even the part that does not require much reinforcement may be used. Since it is reinforced excessively, the weight of the building structure and the cost of parts and materials will increase. Also, for example, as disclosed in Japanese Utility Model Application Laid-Open No. 59-8403, there is a simple one in which reinforcement is simply achieved by a joint metal for joining a square steel pipe and a beam. However, similarly, an increase in material cost cannot be avoided.

The present invention was created in consideration of such a situation, and by appropriately reinforcing the structure according to the form and scale of the building, unnecessary increase in the weight of the building structure and increase in the material cost can be achieved. It is an object of the present invention to provide a square steel pipe for columns that can suppress the increase.

[0010]

In order to achieve the above object, the present invention relates to a rectangular steel pipe for a column, which is a long column having a rectangular cross section and is attached to a column portion of a building structure. The feature is that the thickness is thickened from the center to the end.

[0011]

According to the square steel pipe for a pillar of the present invention, since the wall thickness thereof is thickened from the central portion toward the end portion in the axial direction,
While the bending stress is high at the end where a large amount of horizontal load is applied, no extra reinforcement is applied to the central part where a small amount of horizontal load is applied. Therefore, excessive reinforcement can be eliminated, and unnecessary increase in weight of the building structure and increase in member cost can be suppressed.

[0012]

EXAMPLES Examples of square steel pipes for columns according to the present invention will be described below.
It will be described with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a length L in the axial direction.
Is a rectangular steel pipe for a pillar as a long pillar having a square cross section. The square steel pipe 1 for a pillar is standardized to have a wall thickness a of 4.5 mm.

Steel pipes 2 and 3 having a wall thickness b of 4.5 mm are inserted into the inner peripheral surface of the square prismatic steel pipe 1 for columns from the both ends to L / 3 and spot-welded. That is, the rectangular steel pipe for a column 1 is thickened in thickness from the center to the end in the axial direction.

When this rectangular steel pipe for a column 1 is used as a column of a structure of a rigid frame structure in which a column and a beam are rigidly framed in a box shape, bending stress at the end where a large amount of horizontal load is applied causes Since it is richer than that of, it is less likely to be deflected by a large external force such as an earthquake or typhoon. Further, since the central portion where the horizontal load is not applied is not reinforced excessively, there is no meaningless over-reinforcement, and unnecessary increase of the weight of the building structure and increase of member cost are suppressed.

In this embodiment, the thickening of the square steel pipe for a column is carried out by spot welding a separate steel pipe, but it is integrated by a steel pipe manufacturing technique, or a plate material is attached. Also included in the technical scope of the present invention.

[0017]

As described above, according to the present invention, in a prismatic steel pipe for a pillar, which is a long pillar having a rectangular cross section and is attached to a pillar portion of a building structure, from the center to the end in the axial direction. Since the wall thickness was thickened toward the end, the bending stress at the end where a large amount of horizontal load is applied is abundant, while no extra reinforcement is applied to the central portion where a small amount of horizontal load is applied. Therefore, there is an effect that excessive reinforcement can be eliminated, and unnecessary increase in weight of the building structure and increase in member cost can be suppressed.

[Brief description of drawings]

FIG. 1 shows a square steel pipe for a column according to an embodiment of the present invention, in which (A) is a longitudinal sectional view and (B) is X- in (A).
FIG.

[Explanation of symbols]

 1 Square steel pipe for columns 2 and 3 Steel pipes (thickened wall thickness).

Claims (2)

[Claims] 1. A rectangular steel pipe for a column having a square cross-section attached to a pillar portion of a building structure as a long pillar, wherein a required portion is provided in accordance with the magnitude of a bending moment acting on the pillar portion from a horizontal direction. A square steel pipe for columns, which is characterized by thickening the wall thickness. 2. The pillar according to claim 1, wherein the rectangular steel pipe for a pillar is thicker in a wall thickness at an end portion thereof than a wall thickness at a central portion in an axial direction thereof. Square steel pipe for use.