JPS5915284Y2 - reinforced concrete column - Google Patents

Description

[Detailed description of the invention] This invention relates to reinforced concrete columns for architectural structures.

Despite the revised standards for reinforced concrete structures, damage still occurs due to shear failure of columns during earthquakes.

In the case of school buildings, etc., there are no earthquake-resistant walls in the column direction, and the top and bottom of the columns are defined by leaning walls and waist walls, so the deformability is small and shear failure occurs easily in the center of the building.

This type of damage is particularly common in buildings with a small shear span ratio and a narrow spacing between the sagging wall and waist wall.

This idea was proposed with attention to the above points, and the purpose was to provide a reinforced concrete column with toughness by placing a steel plate parallel to the girder direction in the center of the shrine, which is sandwiched between the leaning wall and the waist wall. With the goal.

The description will be given below based on the drawings.

In Fig. 1, 1 indicates a column, 2 indicates a hanging wall, 3 indicates a waist wall, 4 indicates a window, and 5 indicates the position of a floor slab.

In such a structure, in the event of an earthquake, the pillar 1
The portion sandwiched between the leaning wall 2 and the waist wall 3 is likely to cause shear failure.

6 shows an example of a typical crack that occurs at that time, and the position of this crack 6 may be slightly shifted depending on the fixing conditions between the leaning wall 2 and the waist wall 3 and the column 1.

Note that the ratio of the flexible length a to the flexible length b shown in the figure is the shear span ratio, and as described above, the smaller the shear span ratio, the easier the shear failure will occur.

FIG. 2 shows the conventional reinforcement arrangement of the column 1. Reinforcement of the reinforced concrete column is done according to the load conditions, design cross section, etc. using the conventional calculation method.

In the figure, 8 indicates the main column reinforcement, and 9 indicates the hoop reinforcement.

FIG. 3 shows the reinforcement arrangement of a reinforced concrete column according to an embodiment of this invention. In addition to the column main reinforcement 8 and the hoop reinforcement 9, inside the hoop reinforcement 9 there is a steel plate 10 as shown in FIG. 4 or 5.
has been inserted.

At both ends of this steel plate 10, locking flanges 11.11 are formed by bending and are fixed to the axial reinforcing bars 8, 8 and hoop bars 9, 9, . . . .

This steel plate 10 is arranged so that the surface direction of the steel plate 10 is parallel to the girder direction of a structure having no earthquake walls, and the axial reinforcing bars 8,
The frame is provided so that the flange 11 and 11 portions are passed between the frames 8 and 8.

In addition, although school classrooms and the like usually have earthquake-resistant walls in the direction of beam opening, in cases where there are no earthquake-resistant walls, the steel plate 10
Similar steel plates 10' may also be combined in a crosswise direction in the direction perpendicular to the beam opening direction (steel plates 10 and 10').
Make a cut along the length of one piece at the top and the other at the bottom).

This steel plate 10 is installed in the part sandwiched between the leaning wall 2 and the waist wall 3 in the height direction, but for safety reasons, it is desirable to have an allowance of about 1 m from the window height and width in the vertical direction. .

In addition, in order to fix the steel plate 10 to the main column reinforcement 8 or the hoop reinforcement 9, a horizontal slit 12.12 is provided in the flange 11.11 as shown in FIG.
The locking portion 13, which is formed by partially bending the portion sandwiched between the two, can be locked and fixed by being wrapped around the axial reinforcing bar.

Note that this lateral slit 12 may be provided at any position, and may be provided at the upper end or lower end of the flange 11 and fixed at the upper end, the lower end, or both.

Further, as shown in FIG. 5, a vertical slit 16 is provided at the upper end of the flange 11, this portion is bent outward to provide a locking portion 17, and the locking portion 17 is locked to the hoop muscle 9. You can also do that.

In order to improve the adhesion of the surface of the steel plate 10 to concrete, a striped steel plate having striped irregularities 14 on the surface may be used as the steel plate 10, or holes 1 that are not very large may be used as the steel plate 10.
5 may be used.

This idea consists of the above-mentioned structure, and since steel plates are arranged in the central part of the shrine sandwiched between the leaning wall and the waist wall so that the surface direction is parallel to the girder direction, it is made of reinforced concrete with stiffness in the girder direction. A pillar is obtained.

Therefore, shear failure at the center of the column can be effectively prevented especially in buildings such as school buildings that do not have seismic walls in the column direction.

In addition, the steel plate has a locking flange formed by bending, and the locking part is bent using snots provided in the vertical direction, horizontal direction, or both. Since it locks into place, no special welding is required and processing is simple.

Furthermore, the installation work is extremely simple, and there is no risk of movement during concrete pouring.

Furthermore, as mentioned above, vertical slits can be made in the steel plates in two directions and the steel plates can be combined in a cross pattern for reinforcement.

[Brief explanation of the drawing]

Figure 1 is a front view showing the state of failure that occurs in a conventional reinforced concrete column, Figure 2 is a cross-sectional view showing the reinforcement arrangement of a conventional reinforced concrete column, and Figure 3 is a reinforced concrete column with the steel plate of this invention inserted. 4 and 5 are perspective views of the steel plate used in this invention. 1... Pillar, 2... Hanging wall, 3...
...Waist wall, 4...Window, 5...Floor slab, 6
...Crack, 7...Shear wall, 8...
・・Column main reinforcement, 9・・・・Hoop reinforcement, 10.10'・
... Steel plate, 11 ... Flange, 12 ...
...Slit, 13...Locking part, 14.
...Irregularities, 15...), □...,, Holes, 16.
...slit, 17...locking part, a...
...Possible□Length, b... l /

Claims (1)

[Scope of utility model registration request] In the central part of the shrine, which is sandwiched between the leaning wall and the waist wall, a steel plate with both ends bent to form a locking flange is placed so that its surface direction is parallel to the column direction, and both flanges are aligned in the axial direction of the column. Insert the frame so as to cross it between the reinforcing bars, and use the vertical or horizontal slits provided in both flanges to engage the partially bent locking parts to the axial reinforcing bars or hoop bars of the column. A reinforced concrete column characterized by being permanently fixed.