JPH08177157A - Connection of column and slab in steel structure - Google Patents

Abstract

PURPOSE: To obviate the need for considering the bending bearing force of a slab when the bearing force of a steel column is designed, and make the steel column smaller in cross sectional size by preventing the slab and the steel column from mutually interfering with each other at the connecting section of the slab and the steel column. CONSTITUTION: A steel girder 12 formed out of wide flange shapes is connected to a steel column 10 formed out of a hollow steel pipe in a rectangular shape in cross section, and a slab 14 is formed over the upper surface of the upper flange 12a of the steel girder 12. A gap δ of a specified clearance is provided between the circumference of the steel column 10 and the slab 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an assembling structure of a steel frame column and a slab formed above a steel frame beam connected to the steel frame column.

[0002]

2. Description of the Related Art Generally, in a steel frame structure, a slab is formed on an upper side of a steel beam connected to a steel column, and the slab is closely attached to the periphery of the steel column.

When designing such a steel frame structure, a beam yield precedent design in which a steel frame beam is first yielded has been performed because a steel frame beam is first yielded because a large accident will occur if the steel frame column is destroyed first. At this time, in order to ensure the leading of the beam yield, regarding the steel column, the proof stress of the steel column is designed with a safety factor of 1.2 times the sum of the beam steel proof stress and the bending proof strength of the slab in the compression direction. In this way, the steel columns are given extra capacity.

[0004]

However, in such a conventional steel frame structure, the slab is formed so as to be in close contact with the periphery of the steel column as described above at the joint portion between the steel column and the slab. Therefore, it is necessary to determine the design value of the proof stress of the steel column considering the bending proof stress of the slab from the relationship with the relationship with this slab, and the bending proof stress of the slab must also be included in this way. As much as this is not the case, the required proof stress for steel columns will inevitably increase, and there is a problem that the column cross-sectional size must be increased.

Further, in the conventional design, the effect of the slab closely contacted with the periphery of the steel column on the steel beam has not been fully taken into consideration when evaluating the bending deformation ability of the steel beam end. That is, in the conventional structure of the steel column and the slab, when the compressive force acts on the slab, the neutral axis of the steel beam will shift to the upper flange side of the steel beam due to the presence of this slab. . As a result, in such a situation, it is considered that stress lower than expected at the design stage is concentrated on the lower flange of the steel beam. This is estimated from the fact that many cracks were found in the lower flange of the steel beam in the damage analysis of the Northridge earthquake that occurred in January 1994.

In view of the conventional problem, the present invention prevents the slab and the steel frame column from interfering with each other at the joint between the steel frame column and the slab, thereby designing the yield strength of the steel column. An object of the present invention is to provide a structure for assembling a column and a slab in a steel frame structure, which makes it possible to reduce the cross-sectional size of the steel frame column without having to consider the bending strength of the slab.

[0007]

In order to achieve the above object, the present invention is a frame structure in which a slab is formed above a steel frame beam connected to a steel frame column, and a gap is provided between the steel frame column and the slab. Is provided.

Further, it is characterized in that the gap is filled with a cushioning member.

[0009]

With the above construction, in the structure for connecting the column and the slab in the steel frame structure of the present invention, since a gap is provided between the steel column and the slab, the slab and the steel frame column are mutually provided by this gap. Interference can be prevented.
Therefore, it is not necessary to consider the bending strength of the slab when designing the proof stress of the steel column, and the proof stress required for the steel column can be reduced accordingly, and the cross-sectional size of the steel column can be reduced. can do. Also, it is possible to eliminate the shift of the neutral axis in the steel beam during compression of the slab due to the close contact between the slab and the steel column, prevent stress concentration on the lower flange of the steel beam, and improve the soundness of the frame. At the same time, the design can be facilitated.

Further, by filling the gap with a cushioning member, the cushioning member can fill the gap between the slab and the periphery of the steel frame column, and when the deformation external force acts, the cushioning member becomes flexible. It is possible to prevent the interference between the steel column and the slab by being deformed, and it is also possible to function as a spacer when the slab concrete is placed.

[0011]

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. FIG. 1 and FIG. 2 show an embodiment of a structure for mounting a column and a slab in a steel structure of the present invention. FIG. 1 is a sectional front view of a main part of the connecting portion, and FIG. 2 is a plan view of a main part of the connecting portion. is there.

That is, the structure of the column and the slab in the steel frame structure of this embodiment is applied to the steel frame structure, and the steel beam 12 is connected to the steel column 10 as shown in FIG. The slab 14 is formed.

The steel column 10 is formed by a hollow steel tube having a rectangular cross section, and the steel beam 12 is provided with upper and lower flanges 12.
It is formed of H-shaped steel provided with a and 12b and a web 12c, and the steel beam 12 is connected to the side surfaces 10a, 10a of the steel column 10 from four sides. The slab 14 is constructed by placing slab concrete on the upper surface of the upper flange 12a of the steel beam 12.

Here, in the present embodiment, when forming the slab 14, as shown in FIG. 2, a spacer (not shown) is temporarily installed around the steel column 10 and slab concrete is poured, and the slab concrete is cast. After hardening, the spacer is removed, and a predetermined amount of gap δ is provided at the joint between the steel frame column 10 and the slab 14. The gap δ is set so that the slab 14 and the steel column 10 do not interfere with each other due to the external deformation force.

With the structure described above, in the structure for connecting the column and the slab in the steel frame structure of this embodiment, the steel frame column 10 is used.
Since a predetermined amount of gap δ is provided between the slab 14 and the slab 14, even if a deformation external force such as an earthquake or a strong wind acts on the frame,
In the joint portion between the steel column 10 and the steel column 10, it is possible to prevent the slab 14 and the steel column 10 from interfering with each other due to the gap δ. Therefore, there is no need to consider the bending strength of the slab 14 when designing the proof stress of the steel frame column 10, and the proof stress required for the steel frame column 10 can be reduced accordingly, and the cross-section of the steel frame column 10 can be reduced. The size can be reduced.

In this embodiment, a hollow steel tube having a rectangular cross section is used as the steel column 10, but the cross sectional shape is not limited to this.

FIG. 3 shows another embodiment, in which the same components as those of the above-mentioned embodiment are designated by the same reference numerals, and a duplicate description will be omitted. Note that FIG. 3 is a sectional front view of an essential part of the mating portion corresponding to FIG.

That is, in this embodiment, the buffer member 20 made of an elastic material such as rubber is filled in the gap δ between the steel frame column 10 and the slab 14.

Therefore, in this embodiment, the buffer member 20 can fill the gap δ between the slab 14 and the periphery of the steel frame column 10, and the buffer member 20 can be deformed when a deforming external force acts. It can be flexibly deformed to prevent the interference between the steel column 10 and the slab 14, and can further function as a spacer when the slab concrete is cast.

[0020]

As described above, in the invention of claim 1, since the gap is provided between the steel column and the slab,
This gap can prevent the slab and the steel column from interfering with each other. Therefore, it is not necessary to consider the bending strength of the slab when designing the proof stress of the steel column, and the proof stress required for the steel column can be reduced accordingly, and the cross-sectional size of the steel column can be reduced. can do. Also, it is possible to eliminate the shift of the neutral axis in the steel beam during compression of the slab due to the close contact between the slab and the steel column, prevent stress concentration on the lower flange of the steel beam, and improve the soundness of the frame. At the same time, the design can be facilitated.

According to the second aspect of the invention, since the buffer member is filled in the gap, the buffer member can fill the gap between the slab and the periphery of the steel frame, and the external deformation force acts. In this case, the cushioning member is flexibly deformed to prevent interference between the steel column and the slab, and further, it can also function as a spacer when pouring the slab concrete.

[Brief description of drawings]

FIG. 1 is a cross-sectional front view of a main part of a joint portion showing an embodiment of a joint structure of a column and a slab in a steel frame structure according to the present invention.

FIG. 2 is a cross-sectional plan view of an essential part of a mating portion showing an embodiment of the present invention.

FIG. 3 is a sectional front view of an essential part of a mating portion showing another embodiment of the present invention.

[Explanation of symbols]

 10 Steel Column 12 Steel Beam 14 Slab 20 Buffer Member δ Gap

Claims (2)

[Claims] 1. A column and a slab in a steel frame structure, wherein a slab is formed above a steel beam connected to the steel column, and a gap is provided between the steel column and the slab. Intercommunicating structure. 2. The mounting structure for a column and a slab in a steel frame structure according to claim 1, wherein the gap is filled with a cushioning member.