JPH0541776B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for arranging main reinforcements in reinforced concrete columns that can improve the two-way shear performance of columns.

[Background of the Invention] When columns of general reinforced concrete structures are subjected to shearing force and bending moment due to earthquake loads, cracks increase and they rapidly lose their bearing strength, causing the risk of the structure collapsing. That is, reinforced concrete columns are hard, brittle, and have low toughness.

In order to solve these drawbacks, various research and developments have been carried out in the past, such as Japanese Patent Application Laid-Open No. 152779/1986.
No. 2, No. 2003-11-112 discloses a technique relating to a so-called two-way X-shaped reinforcement column in which a pair of reinforcing bars are arranged so as to be inclined in opposite directions so as to intersect with each other in a side view.

However, this technique has the disadvantage that the inside of the rectangular cross section is blocked by the diagonally arranged main reinforcement, which obstructs the insertion of a vertical chute or bar vibrator during concrete pouring. There is a drawback that it cannot be done.

In addition, in Special Publication No. 60-2463, there are two
A technique has been disclosed that mechanically connects one or four diagonal reinforcements and longitudinal main reinforcements and assembles four sides of a planar truss body made of concrete as horizontal members.

However, in this technique, the mechanical connection parts of the diagonal reinforcement to the longitudinal main reinforcement are located at all four corners of the rectangular cross-section column and at the joint, so the work at the mechanical connection part becomes extremely complicated. It has the disadvantage of being complicated.

[Objective of the Invention] Therefore, the object of the present invention is to improve the two-way shearing performance of columns, to prevent the structure from collapsing due to increased cracks and sudden loss of bearing strength, and furthermore, to prevent the structure from collapsing when concrete is poured To provide a method for arranging main reinforcement in a reinforced concrete column, which facilitates the insertion of a vertical chute or bar vibrator, improves workability, and facilitates the arrangement of core reinforcing bars and core steel frames.

[Means for Solving the Problems] The present inventor has made extensive studies to achieve the above object, and as a result, has arrived at the present invention.

That is, the reinforcement method for main reinforcement in a reinforced concrete column of the present invention is such that, in a rectangular cross-section column of a reinforced concrete structure, intermediate main reinforcements excluding the corner main reinforcements at the four corners intersect in an X shape within each side of the rectangular cross-section column. Instead, the intermediate main reinforcements are arranged diagonally between adjacent corner main reinforcements so that when the rectangular cross-section column is viewed from the side, the opposing sides appear to intersect in an X shape. do.

[Specific structure of the invention] The present invention will be explained in detail below.

In the present invention, the columns of the reinforced concrete structure (for example, buildings) may be either short columns or long columns, and the column has a rectangular cross section.

This rectangular cross-section column is provided at a predetermined location in a building, etc., and a beam is provided on the column corresponding to each floor.

Corner main reinforcements are arranged at the four corners of this rectangular cross-section column, and intermediate main reinforcements other than these corner main reinforcements constitute an X-shaped reinforcement within each side of the rectangular cross-section column, that is, only within one side. Instead of intersecting each other, it is only when the opposing sides come together when the rectangular cross-section column is viewed from the side (the four sides of the rectangular cross-section column are viewed from a direction perpendicular to each side) that it becomes an X-shape. The reinforcement is arranged so that it appears to intersect with the .

In this case, the crossing position may be approximately in the middle of each level, but it may also be in the middle of two levels (the part where the beam is located). Furthermore, it is also possible to intersect in the middle of three or more hierarchies, but in that case, it is preferable to combine the above-mentioned intersects in the middle of each hierarchy. In this case, it goes without saying that it is preferable to plan and devise a configuration with the minimum number of main reinforcements.

[Example] Examples of the present invention will be described below.

First, based on FIGS. 1 and 2, a case is shown in which one intermediate reinforcement is used for each side of the column.

1 and 2 are diagrams representing this embodiment. FIG. 1 is a schematic side view showing an example of a rectangular cross-section column to which the present invention is applied, and FIG. 2 is a cross-sectional view taken along the line - be.

In the figure, 1 is a column with a rectangular cross section, and 2A~
2C is the girder, and 2' is the girder main reinforcement.

3A to 3D are corner main reinforcements that are the main reinforcements at the four corners of the column.

4A is an intermediate main reinforcement provided between the corner main reinforcements 3A and 3B, and is arranged so as to slope upward from the corner main reinforcements 3A toward 3B between the girders 2B and 2C.

Further, an intermediate main reinforcement 4C is arranged at a position facing the intermediate main reinforcement 4A, and the intermediate main reinforcement 4C is arranged so as to be upwardly inclined from the corner main reinforcement 3C toward the corner main reinforcement 3D.

Similarly, an intermediate main reinforcement 4B is provided between the corner main reinforcements 3B and 3C, and an intermediate main reinforcement 4D is provided between the corner main reinforcements 3D and 3A.

As a result of arranging the intermediate main reinforcements 4A to 4D in this way, the intermediate main reinforcements 4A and 4C appear to cross each other in an X shape for the first time when viewed from the Y ₁ or Y ₂ direction, and the intermediate main reinforcements 4B and 4D appear to intersect with each other in an X shape. ₂ or X When viewed from _one direction, they appear to intersect with each other in an X shape.

As described above, when corner main reinforcements and _intermediate main reinforcements are arranged, a part ( _component force ₎ of the shearing force in the X ₁ - Since the 4D is borne by tensile force, it is possible to prevent shear failure of the reinforced concrete column 1 in the event of a large earthquake, and the shear force borne by the hoop 1F is reduced, making the cross section of the hoop reinforcement smaller.
Alternatively, there is an advantage that the number of hoop reinforcements can be reduced, and furthermore, since the inside of the rectangular cross section is empty, it is possible to insert a core steel frame (for example, a steel frame with an H-shaped cross section) or a core reinforcing bar.

In addition, the above-mentioned plurality of column main reinforcements, that is, corner main reinforcement 3
Band reinforcements (not shown) are provided around A to 3D and intermediate main reinforcements 4A to 4D.

Next, based on FIG. 3, a case is shown in which two intermediate main reinforcements are used for each side of the column.

In Figure 3, 5A and 5B are corner main reinforcements 3
This is an intermediate main reinforcement placed between A and 3B, and these two intermediate main reinforcements 5A and 5B are placed at the farthest position in the section of the girder 2A, and are the closest at the section of the girder 2B. Further, in the area of the girder 2C, the intermediate main reinforcement is again placed at the farthest position. Intermediate main reinforcements 6A and 6B are arranged on the opposite side of the column surface where intermediate main reinforcements 5A and 5B are provided.

Therefore, intermediate main bars 5A and 6A, and intermediate main bars 5B
and 6B cross each other in an X shape when viewed from the side, and the object of the present invention can be achieved.

Note that FIG. 4 is a cross-sectional view showing a reference example in which cross-reinforcement is arranged in an X shape within one side surface. Intermediate main reinforcement 4C' (intermediate main reinforcement 4C) whose inclination direction is opposite to intermediate main reinforcement 4A
The same slope) is connected to the intermediate main reinforcement 4A, and the reinforcement is arranged in an X shape between the corner main reinforcements 3A and 3B, and the corner main reinforcements 3B and 3C, 3C and 3D,
Between 3D and 3A, new intermediate main reinforcements 4D', 4A', and 4B' with opposite inclination directions are similarly added to form an X-shaped reinforcement arrangement.

[Effects of the Invention] According to the present invention, the intermediate main reinforcements are arranged diagonally between adjacent corner main reinforcements so that when a rectangular cross-section column is viewed from the side, the opposing side surfaces cross in an X shape. By having a striated structure, a part of the horizontal shearing force (component force) that the column receives is borne by the intermediate main reinforcements on the opposing sides as a tensile force.
It is possible to prevent shear failure of columns during large earthquakes.

Further, according to the present invention, since the inside of the rectangular cross section is empty, it is easy to insert a vertical chute or a bar vibrator during concrete pouring, and workability can be improved. Easy to install.

Therefore, a reinforced concrete column with improved shear strength can be obtained.

Furthermore, since the shearing force applied to the hoop muscles is reduced, the cross section of the hoop muscles can be made smaller or the number of hoop muscles can be reduced, and the structural members can be made lighter or simpler.

In addition, according to the present invention, the connection to the longitudinal main reinforcement can be done in half of the technique described in Japanese Patent Publication No. 60-2463, so the reinforcement work is easy.

[Brief explanation of the drawing]

1 and 2 are diagrams representing this embodiment, in which FIG. 1 is a schematic side view showing an example of a rectangular cross-section column to which the present invention is applied, and FIG. 2 is a cross-sectional view taken along the - line in FIG.
FIG. 3 is a schematic side view showing another embodiment of the present invention;
FIG. 4 is a sectional view showing a reference example. 1: Rectangular cross-section column, 2A to 2C: Large beam, 2': Main beam main reinforcement, 3A to 3D: Corner main reinforcement (column main reinforcement at four corners), 4A to 4D: Intermediate main reinforcement (column main reinforcement other than corner main reinforcement).

Claims (1)

[Claims] 1 In a rectangular cross-section column of a reinforced concrete structure, the intermediate main reinforcements excluding the corner main reinforcements at the four corners do not intersect in an X shape within each side of the rectangular cross-section column, but when the rectangular cross-section column is viewed from the side. The sides facing each other appear to intersect in an X shape.
A reinforcement arrangement method for reinforced concrete column main reinforcements, characterized in that the intermediate main reinforcements are arranged diagonally between adjacent corner main reinforcements.