JPS5953975B2 - Steel reinforced concrete column structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a steel reinforced concrete column structure.

In a steel-frame reinforced concrete frame structure, if the structural members have sufficient toughness when they reach the inelastic region during a strong earthquake, the seismic safety of the frame structure can be expected to improve.

However, in steel-framed reinforced concrete columns that are subjected to repeated bending and shearing forces during earthquakes, the adhesion effect between the conventional built-in column steel and concrete cannot be expected.
The Architectural Institute of Japan's 1975 "Steel-Frame Reinforced Concrete Structural Calculation Standards and Explanations" also states that, as a general rule, the steel columns should be designed without any expectation of adhesion to the concrete. The current situation is that this is not sufficient.

In contrast to conventional general column steel frames, concrete-filled steel pipe structures, known as a type of steel-frame reinforced concrete column structures, have excellent mechanical toughness, but they are difficult to place on-site when pouring concrete and on-site. There were difficulties in processing the joints, fitting the main beam reinforcements at the column-beam joints, and fireproof coating.

As a means to improve this difficulty, a steel-framed reinforced concrete column structure has been proposed, in which the column steel frame is a cylindrical structure made of steel plates with square holes drilled in a lattice pattern.

Although this column eliminates the drawbacks of the above-mentioned concrete-filled steel pipe structure, the steel plate used has disadvantages such as loss.

The present invention further improves the steel-framed reinforced concrete column made of the cylindrical column steel frame assembled from the steel plates with square holes,
The object of the present invention is to provide a steel-framed reinforced concrete column material that uses a cage-like steel tube shell for the column steel frame, which is more rational in terms of structural mechanics and saves materials.

That is, the present invention provides a cage-like steel tube shell A which is formed by superimposing a cloth-wrapped spiral steel strip 2 and a cloth-wound spiral steel strip 1 as shown in FIG. ,
As illustrated in FIG. 2, this is a steel-frame reinforced concrete column body B with steel columns.

As shown in Fig. 3, the above-mentioned cage-like steel pipe shell A is manufactured by arranging the steel strips 2' in parallel at small intervals in the diagonal direction, and then placing the steel strips 1' on top of the steel strips 1' in the symmetrical diagonal direction. Arranged in parallel with small intervals,
The intersection part 3 is welded 4 to form a ridge-shaped steel plate 5, and this ridge-shaped steel plate 5 is curved into a cylindrical shape and both sides are butted and welded. A spiral steel strip 2 is formed, a long steel strip is wound around the outside of the spiral steel strip 1 to form a cloth-wrapped spiral steel strip 1, and the overlapping intersection portions 3 of the spiral steel strip 1 are welded 4.

Therefore, the cage-like steel pipe shell A is used as a column steel frame of a steel reinforced concrete column structure B illustrated in FIG.
buried inside.

In addition, 7 shown in FIG. 2 is a column main reinforcement, and 8 is a hoop reinforcement or a spiral hoop reinforcement.

In the steel reinforced concrete column structure B of the present invention constructed in this way, the cage-like steel pipe shell A becomes a member that can simultaneously resist bending moment, shear force, and axial compressive force.

In other words, the concrete inside the cage-like steel pipe shell A and the cage-like steel pipe shell A mutually restrain the crushing of the concrete and the buckling of the steel material of the steel pipe shell, and have a great effect of strengthening both against crushing and buckling. .

Further, since the cage-shaped steel pipe shell A is cage-shaped, it has a large adhesion effect with concrete, and becomes a steel reinforced concrete column with high toughness.

In addition, during construction, concrete can be easily poured into the interior, and reliable joints can be easily formed using high-strength bolts for on-site joints.

Furthermore, the cage-shaped steel tube shell A has the advantage that it can be produced more economically than commercially available copper strips without wasting material.

Furthermore, by changing the inclination angle θ of the Ishinomaki spiral steel strip 1 and the left-handed spiral steel strip 2, the cage-like steel tube shell A can adjust the ratio of resistive bending moment and resistive shearing force, and the structural design It is convenient for

In addition, as illustrated in Figures 4 and 5, in the case of a frame structure that receives large bending moments in each of the x and y directions, reinforcing vertical rib steel 9 such as steel strip, L-shaped steel, and ■-shaped steel is used. Cage-shaped steel pipe shell A
By assembling and cooperating in the X and y directions of
The column steel frame can be used to accommodate large bending moments in different directions.

The reinforcing vertical rib steel 9 is assembled into the cage-like steel tube shell A by drilling a slit in the web, inserting the left-handed and left-handed spiral steel strips 1 and 2 into the slits, and welding them 4'. It is something that can be done.

Further, the steel reinforced concrete column B of the present invention has hoop reinforcements or spiral hoop reinforcements 8 as illustrated in FIG.
By using it in combination, the restraint effect on concrete becomes stronger, resulting in a frame structure with high toughness and excellent earthquake resistance.

Next, in addition to the circular cross section shown in Figure 3, the cross section of the column can also be polygonal, such as a hexagon, as shown in Figure 6. In this case, the cage-shaped steel pipe shell also conforms to this. It is formed into a polygon.

[Brief explanation of the drawing]

The accompanying drawings illustrate the invention by way of example,
Fig. 1 is a perspective view of a part of the cage-like steel pipe shell used in the present invention, Fig. 2 is a cross-sectional view of the steel reinforced concrete column structure of the present invention using the cage-like steel pipe shell shown in the previous figure, and Fig. 3 is a Fig. 1 is a top view of a conical steel plate showing an example of manufacturing a cage-like steel pipe shell; Fig. 4 is a perspective view of a part of a cage-like steel pipe shell assembled with reinforcing vertical rib steel;
FIG. 5 is a cross-sectional view of a steel reinforced concrete column using the cage-like steel pipe shell shown in the previous figure, and FIG. 6 is an explanatory diagram showing a column with a hexagonal cross section. 1...Left-handed spiral steel strip, 2...
Left-handed spiral steel strip, 1', 2'... Steel strip, 3... Crossing part, 4, 4'... Welding, 5... Contoured steel plate, 6... Concrete, 7... Column main reinforcement, 8... Hoop reinforcement or spiral hoop reinforcement, 9... Reinforced vertical rib steel, A ...Cage-shaped steel pipe shell, B...Steel-framed reinforced concrete column body.

Claims (1)

[Claims] 1. A steel-framed reinforced concrete column structure characterized in that the column steel frame is a cage-like steel pipe shell formed by superposing and welding a cloth-wrapped spiral steel strip and a cloth-wrapped spiral steel strip.