JP2000027368A - Steel encased reinforced concrete-constructed column - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the structure of a steel encased reinforced concrete- constructed column, in which buckling strength is increased and which can resist to usage under high axial force. SOLUTION: In the steel encased reinforced concrete-constructed column, in which column steel frames 3 having flange sections 6 and reinforcing bars arranged around the column steel frames 3 are included, the flange sections 6 formed to steel-framed webs 5 projected in the outer circumferential direction are installed, and sections among the mutual flange sections 6 and steel-framed webs 5 are connected by reinforcing horizontal rib plates 7. The reinforcing horizontal rib plates 7 are mounted so as to mutually bridge each of the surfaces and rears of the steel-framed webs 5 and each of the adjacent flange sections 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a column structure, and more particularly to a column structure suitable for application to a steel reinforced concrete structure under high axial force.

[0002]

2. Description of the Related Art A conventional steel-framed reinforced concrete column has a structure in which a main reinforcing bar and a band are arranged around an outer periphery of a column steel frame mainly composed of H steel. FIG. 4 shows a conventional reinforcing bar structure in a reinforced concrete column. In this method, H-shaped steels 10 and 11 are crossed to form a cross shape, and a column-shaped steel frame 30 integrally formed with a flat flange 12 is provided at each of the four projecting tips, and a reinforcing bar 13 , 14 are arranged. The reinforcing bar includes a main reinforcing bar 14 arranged in parallel with the longitudinal direction of the steel frame 30 and a shear reinforcing bar 13 disposed orthogonal to the main reinforcing bar 14. The number of the main bars 14 varies depending on the scale of the concrete column,
On the other hand, the shear reinforcement 13 is at a specific interval, for example, 1
It is arranged every 0 centimeters.

[0003] After such reinforcing arrangement, a formwork (not shown) is arranged around the periphery and concrete is poured into the inside to form a steel reinforced concrete column.

[0004] Such a column is said to have good proof stress deformation performance mainly under a low axial force.

[0005]

However, high axial forces such as the lower part of a super-high-rise building, particularly in the case of steel reinforced concrete columns combined with high-strength concrete, have a large acting axial force, so that the outer periphery of the column steel frame is hardly affected. Due to the deterioration of the concrete and the subsequent buckling of the flange 12, good deformation performance cannot be obtained. That is, since only the shear reinforcing bars 13 arranged on the outer peripheral portion of the column steel frame do not sufficiently restrain the concrete, the concrete is likely to be broken and the steel frame is buckled.

At the time of such a high axial force, if local buckling can be suppressed from occurring early on the flange 12 of the H-section steel,
It is considered that the deformation performance of steel reinforced concrete columns can be improved.

[0007] On the other hand, a column having a high axial force could not cope with the problem other than increasing the column cross section to reduce the acting axial stress. If the column cross section becomes large, there is a problem that the frame cost increases and the effective floor area of the building decreases.

The present invention has been made in view of such a point of view, and an object of the present invention is to provide a column structure which can improve the buckling strength and withstand use under a high axial force.

[0009]

Means for Solving the Problems The present invention is configured as follows to solve the above-mentioned technical problems. That is, in a steel frame having a flange portion and a steel-framed reinforced concrete column including a reinforcing bar arranged therearound,
A flange formed on a steel web protruding in the outer peripheral direction was provided, and the flange and the steel web were connected to each other by a reinforcing horizontal rib plate. The reinforcing horizontal rib plate is provided so as to bridge each of the front and back surfaces of the steel web and each of the adjacent flange portions.

Further, a perforated portion is formed in the steel web, and a U-shaped reinforcing bar is inserted through the perforated portion and arranged so as to surround the flange portion of the steel frame to improve the binding force of the concrete. Configuration. (Steel frame) Generally, a steel column having a flange portion such as H steel or T-shaped steel used for a steel reinforced concrete column, and a shape combining these are used. (Reinforcement horizontal rib plate) A plate made of a rigid steel plate is preferable. This is desirably attached to the column capital part and the column base part, and the arrangement range in the axial direction may usually be about 0.5 to 1 times the steel frame (depth of the steel frame). (U-shaped reinforcing bar) It is preferable that a general different-diameter reinforcing bar is bent into a U-shape. The U-shaped reinforcing bars arranged so as to surround the flange portion can oppose each other and can be fixed.

The U-shaped reinforcement is fixed to the concrete portion near the center of the column confined by the flange portion, so that the U-shaped reinforcement has a good anchoring performance, and can be sufficiently used as a reinforcement without welding to a steel frame or other reinforcing bars. Can demonstrate performance.

As described above, according to the present invention, the flange portion of the H-section steel and both side surfaces of the web are joined by the reinforcing horizontal rib plate at the column head and column base where the stress is large under high axial force, and the flange portion is supported. , The buckling phenomenon of the flange portion out of the plane can be effectively suppressed at the time of large deformation with high axial force. Thereby, the deformation performance of the column at the time of large deformation is greatly improved.

Further, by providing the reinforcing horizontal rib plate, the binding force of the concrete surrounded by the flange portion is improved, so that the integration of the steel frame and the concrete is enhanced.

Under the same conditions, a column having such a structure
Since the cross-sectional area of the pillar can be made smaller than before, the frame cost can be reduced and the degree of freedom in designing the building can be improved.

[0015]

(Embodiment 1) Hereinafter, the structure of a steel reinforced concrete column according to Embodiment 1 of the present invention will be described in more detail with reference to FIG. 1 and FIG.

FIG. 1 is a longitudinal sectional view of a steel reinforced concrete column, and FIG. 2 is a transverse sectional view thereof. Column steel 3 is H-shaped steel 1,
2 are integrally formed in a cross-shaped shape,
A flange 6 is attached to the tip of the steel web 5 projecting in four directions.
Are formed.

As shown in FIG. 2, the right and left ends of the surface of the flange portion 6 facing the steel web 5 and the flange portion are located at the upper part of the columnar steel frame 3 made of the H-shaped steels 1 and 2. A trapezoidal reinforcing horizontal rib plate 7 is provided so as to connect with both side surfaces of the steel web 5 connected to the steel web 5. That is, reinforcing horizontal rib plates 7, 7 are provided symmetrically on the left and right around the steel frame web 5.

In a similar state, a reinforcing rib plate 7 is also attached to a column base below the column steel frame 3.

These reinforcing horizontal rib plays 7 are made of a trapezoidal steel plate, and bridge the surface of the flange portion 6 on the steel web side with the steel web 5, and are joined to the flange portion 6 and the steel web 5 by welding means. ing. The reinforcing horizontal rib plate 7 is provided at a pitch of about 0.5 to 1 times the column formation (depth of the column) of the column cap and the column base, and at a pitch of about 1/3 of the steel frame.

The structure of the other parts is the same as that of a normal steel-framed reinforced concrete column. A main reinforcing bar 14 is arranged parallel to the column steel frame 3 in the longitudinal direction on the outside thereof.
The shear reinforcement 13 is arranged so as to be orthogonal to 4. The shear reinforcing bar 13 is arranged so as to surround the column steel frame 3 by bending a reinforcing bar into a rectangular shape.

After the reinforcing bars are arranged as described above, a formwork (not shown) is arranged around the column steel frame 3 and concrete is poured into the inside to form a steel reinforced concrete column 8. If the concrete used is relatively fluid,
Even if the reinforcing horizontal rib plates 7 are present, no gap is created between the column steel frame 3 including these and the concrete.

In a steel reinforced concrete column having a general structure, when a horizontal stress is generated, when a high axial load is applied,
In the column having the conventional configuration, stress is applied in a direction in which the concrete and the column steel frame 3 are peeled off, so that the concrete is broken and, at the same time, the buckling of the flange portion to the outside of the plane is likely to occur.

In the column having the above-described structure, particularly, the early buckling of the flange portion of the column steel frame 3 is suppressed, so that the concrete is not easily destroyed, and the seismic resistance of the building is greatly improved. it can. (Embodiment 2) Embodiment 2 of the invention will be described with reference to FIG.

The steel frame 3 is formed integrally by crossing H-shaped steels 1 and 2 in a cross shape, and a flange portion 6 is integrally provided at the tip of each of the steel frame webs 5.
And two perforations 4 are provided at predetermined intervals at the same height position in each of the steel webs 5 and 5. The perforation position of the perforation part 4 is such that the perforation positions of the two perforation parts 4 provided on one web 5 are the same height, but the other web 5
Are different from the drilling positions of the two drilling portions 4 provided in the first hole. A plurality of U-shaped reinforcing bars 8 formed in a U-shape are inserted into each of the perforations 4. In order to prevent collision between the U-shaped reinforcing bars 8, a positional difference of about the diameter of the U-shaped reinforcing bars 8 is provided.

The U-shaped reinforcing bars 8 are formed of U-shaped rebars of different diameters, and the respective tips are inserted into the perforated portions 4.

Further, the U-shaped reinforcing bars 8 are inserted from the front and back surfaces of the web 1 and also from the front and back surfaces of the web 2, and a considerable portion of the reinforcing bars overlap. Thus, four U-shaped reinforcement bars 8 are inserted on the same plane.

Thus, as shown in FIG. 3, each flange 6 is surrounded by the U-shaped reinforcing bar 8. In the same configuration, the perforated portions 4 are provided at specific intervals in the height direction of the steel frame web 3, so that the U-shaped reinforcing bars 8 are arranged hierarchically.

Further, it is preferable to provide the vertical bar 7 so as to hit the corner of the U-shaped reinforcing bar 8.

As in the first embodiment of the present invention, the left and right ends of the flange 6 facing the steel web 5 side are connected to the flange 6 at the upper column cap and column base of the column steel frame 3. As to connect both sides of the steel web 5,
A trapezoidal reinforcing horizontal rib plate 7 is provided.

According to the combination of the U-shaped reinforcing bar 5 and the reinforcing horizontal rib plate 7, the U-shaped reinforcing bar 5 is located in the concrete constrained by the flange portion 6 and the lower the higher the axial force, the lower the reinforcing bar 5 becomes. Strongly adheres to concrete. Therefore, the restraining force of the concrete is improved, and even when a bending stress occurs at the time of a high axial load, the crushing of the compression side concrete can be prevented.

Next, the reinforcing rib plate 7 increases the buckling strength of the columnar steel frame 3, especially the flange portion 6.

Due to these synergistic effects, the compressive strength of the column is dramatically improved, the buckling of the steel frame is less likely to occur in a high-axial steel reinforced concrete column, and the deformation performance of the column during large deformation is greatly improved. To improve.

[0033]

According to the present invention, a steel frame reinforced concrete column having a high axial force is unlikely to cause buckling of the steel frame, so that the deformation performance at the time of large deformation is improved, and a building excellent in earthquake resistance can be provided.

Further, since the column section can be reduced by improving the deformability, a steel reinforced concrete column which can be effectively used in the lower layers of a high-rise building or a high-rise building can be provided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a steel reinforced concrete column according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of a steel-framed reinforced concrete pillar according to an embodiment of the present invention.

FIG. 3 is a longitudinal section of a steel reinforced concrete column according to another embodiment of the present invention.

FIG. 4 is a perspective view showing a reinforcing bar structure of a conventional building.

[Explanation of symbols]

 1, 2 H-shaped steel 3 Column steel 4 Drilled part 5 Web 6 Flange 7 Reinforced horizontal rib plate 8 U-shaped reinforcement

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] July 16, 1998 (1998.7.1)
6)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0026

[Correction method] Change

[Correction contents]

Furthermore co-type reinforcement 8 while being inserted from the front and back surfaces of one of the web 5, are inserted from the front and back surfaces of the other web 5, corresponding parts are overlapped. Thus, four U-shaped reinforcement bars 8 are inserted on the same plane.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0027

[Correction method] Change

[Correction contents]

Thus, as shown in FIG. 3, each flange 6 is surrounded by the U-shaped reinforcing bar 8. In the same configuration, the perforated portions 4 are provided at specific intervals in the height direction of the steel web 5 , so that the U-shaped reinforcing bars 8 are arranged hierarchically.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0029

[Correction method] Change

[Correction contents]

[0029] Then similarly to the first embodiment of the invention, in the stigma and the column base of the upper portion of the pillar steel 3, left and right side end of the surface facing the steel web 5 side of the flange portion 6, to the flange portion 6 A trapezoidal reinforcing horizontal rib plate 7 is provided so as to connect both side surfaces of the connected steel frame web 5.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0030

[Correction method] Change

[Correction contents]

According to the combination of the U-shaped reinforcing bar 8 and the reinforcing horizontal rib plate 7, the U-shaped reinforcing bar 8 is located in the concrete constrained by the flange portion 6, Strongly adheres to concrete. Therefore, the restraining force of the concrete is improved, and even when a bending stress occurs at the time of a high axial load, the crushing of the compression side concrete can be prevented.

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] Explanation of sign

[Correction method] Change

[Correction contents]

[Description of Signs] 1, 2 H-section steel 3 pillar steel frame 4 perforated section 5 web 6 flange section 7 reinforcing horizontal rib plate 8 U-shaped reinforcing bar

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Takayuki Imaizumi 2-10-26 Fujimi, Chiyoda-ku, Tokyo Maeda Construction Industry Co., Ltd. F-term (reference) 2E163 FA02 FB05 FD03 FD42 FD43 FD46

Claims (2)

[Claims] 1. A steel frame having a flange portion and a steel frame reinforced concrete column including a reinforcing bar arranged around the flange portion, a flange portion formed on a steel web projected in an outer peripheral direction is provided, and the flange portion and the steel frame web are provided. Are connected by a reinforcing horizontal rib plate, and the reinforcing horizontal rib plate is provided so as to bridge each of the front and back surfaces of the steel web and each of the adjacent flange portions with each other. Steel reinforced concrete columns. 2. A steel reinforced concrete according to claim 1, wherein a perforated portion is formed in said steel frame web, and a U-shaped rebar is inserted into said perforated portion and arranged so as to surround a flange portion of said steel frame. Pillars.