JPS6233963A - Distribution structure of rc pillar using x-shaped steel bar - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a reinforcement structure for RC columns using X-shaped reinforcement.

[Conventional technology]

As shown in Figures 7 and 8, the reinforcement structure of an RC column using X-type reinforcement is that between the vertical column main reinforcements 1 at the four corners, there are vertical reinforcement sections 2a corresponding to the column and beam joints 3. and the vertical bar part 2
The bent column main reinforcements 2, which are composed of upper diagonal reinforcements 2b and lower diagonal reinforcements 2c bent diagonally from above and below a, are arranged in an X-shape in side view, and the vertical column main reinforcements 1... It is already known that the hoop muscle 7 is wrapped around the hoop.

[Problem that the invention seeks to solve]

The X-shaped reinforcement method has more than twice the energy absorption capacity compared to the normal reinforcement method, which mainly uses vertical and horizontal reinforcement, and has dramatically improved toughness and strength, and can withstand alternating horizontal loads during earthquakes. It has been experimentally confirmed that it is effective in preventing shear failure of columns and walls that are subject to damage. However, the conventional reinforcement structure has the following problems.

(1) Since the vertically adjacent bent column main reinforcements 2 are joined by gas pressure welding, the bending point (position P in the figure) between the vertical foil portion 2a and the lower diagonal reinforcement 2C is the amount of shrinkage due to pressure welding. It moves downward, making it difficult to obtain construction accuracy. In addition, if there is poor accuracy,
Modification of reinforcement arrangement is not possible.

(2) In the X-type reinforcement arrangement, the anchoring length of the diagonal reinforcement to the concrete of the column-beam joint part 3 cannot be longer than the length of the vertical foil part 2a, so it has a tensile strength similar to that of threaded reinforcement. If a large steel rod is used, there is a possibility that the vertical foil portion 2a may be pulled out (slip in the vertical direction against the concrete at the column-beam joint), and the inherent strength of the X-shaped reinforcement may be reduced.

(3) When the vertical column main reinforcements 1 at the four corners and the bent column main reinforcements 2 arranged in an X-shape between them are pre-assembled, they cannot be joined by gas pressure welding, etc., and workability is improved by pre-assembly. It is difficult.

An object of the present invention is to solve these problems.

[Means for solving problems]

Technical measures taken by the present invention to solve the above problems are as follows.

That is, the present invention provides a bent column consisting of a vertical foil section corresponding to the column-beam joint section and an upper diagonal reinforcement and a lower diagonal reinforcement that are bent obliquely from both ends of the vertical reinforcement section between the vertical column main reinforcements at the four corners. In an RC column reinforcement structure in which the main reinforcements are arranged in an X-shape in side view and hoop reinforcements are wrapped around the vertical column main reinforcement group, the vertical column main reinforcements and bent column main reinforcements are screwed, respectively. Knotted reinforcing bars are used in the vertical center of the column and beam joints.
A column reinforcement fixing plate is provided which is formed into a rectangular ring shape in plan view and has a horizontal pressure receiving surface, and the vertical column main reinforcement and the vertical foil portion of the bent column main reinforcement are formed on the column reinforcement fixing plate. The columnar reinforcement fixing plate is fixed to the columnar reinforcement plate by each pair of nuts inserted into the through holes and screwed into the threaded joints of the threaded reinforcing bars, with the columnar reinforcement fixing plate sandwiched from both upper and lower sides by the nuts. It is a feature.

[Effect]

According to the above configuration, the vertical column main reinforcement and the vertical foil portion of the bent column main reinforcement are attached to the column reinforcement fixing plate having a horizontal pressure-receiving surface, and the column reinforcement fixing plate is attached from both upper and lower sides using each pair of nuts. Since they are fixed in a sandwiched state, the column main reinforcements, especially the vertical foil portions of the bent column main reinforcements, are completely prevented from slipping against the concrete at the column and beam joints.

Even if the vertical column main reinforcements at the four corners and the bent column main reinforcements arranged in an X-shape between them are assembled in advance via the column reinforcement fixing plate and nuts, when the nuts are loosened, the Since it is possible to move the main reinforcement of each column in any direction independently of each other within the interior, lock nut type mechanical joints can be used as a means of connecting diagonal reinforcement, correcting the reinforcement arrangement accuracy and improving construction accuracy. is possible.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

Figures 1 and 2 are a front view and a plan view showing the reinforcement structure of an RC column using X-shaped reinforcement, Figure 3 is a perspective view of the main part, and Figure 4 is a perspective view of the main part.
The figure is a side view of the main part, Figure 5 (a).

(B) and (C) are front views showing the construction method.

1... are vertical column main reinforcements arranged at the four corners, 2... are bent column main reinforcements arranged in an X-shape between the vertical column main reinforcements 1..., and these 1. ..., 2... all use threaded reinforcing bars (deformed reinforcing bars with screw-shaped ribs that increase adhesion to concrete). The vertical column main reinforcements 1 and 1 that are vertically adjacent are connected from the column and beam joint part 3 to 1
At a position approximately m above, a female threaded sleeve 4a and a pair of lock nuts 4b.

4b, which is a so-called lock nut type mechanical joint 4. Each bent column main reinforcement 2 includes a vertical foil portion 2a having a length equal to the vertical width β of the column-beam joint portion 3, an upper diagonal reinforcement 2b and a lower diagonal reinforcement 2c that are bent diagonally from both ends of the vertical reinforcement portion 2a. The overall vertical length is the same as that of the vertical column main reinforcement 1. The vertically adjacent bent column main reinforcements 2, 2 are also joined by a lock nut type mechanical joint 4 at a position approximately 1 m higher than the column/beam joint 3.

A column reinforcement fixing plate 5 is provided at the vertical center of the column-beam joint portion 3, which is formed into a rectangular ring shape in plan view and has a horizontal pressure-receiving surface S. The column fixation plate 5 includes
A predetermined number of through holes (blind holes) 5a, which are slightly larger in diameter than the vertical column main reinforcements 1 and the bent column main reinforcements 2, are formed, and the vertical foil portions of the vertical column main reinforcements 1 and the bent column main reinforcements 2 are formed in these through holes 5a. 2a is inserted. and each pair of oaks (6a) that are threadedly engaged with the threaded joints of the vertical column main reinforcement 1 and the bent column main reinforcement 2,
6b, the vertical column main reinforcements 1 and the bent column main reinforcements 2 are fixed to the columnar reinforcement fixing plate 5, with the columnar reinforcement fixing plate 5 being sandwiched from both upper and lower sides by the nuts 6a and 6b.

A hoop reinforcement 7 made of a spiral reinforcement is wrapped around the group of vertical column main reinforcements 1 and fixed with a binding wire or the like.

Reference numeral 8 denotes a beam reinforcing bar consisting of beam main reinforcing bars 9 made of threaded reinforcing bars, and a spiral stirrup 10 wrapped around them and fixed by means such as bundling or welding. The main beam reinforcements 9 at the upper end are held at a predetermined height position by members 11, and the beam supports installed between the vertical column main reinforcements 1 at the four corners are held at a predetermined height position. In each of the illustrated beam supports, the member 11 is formed of an angle material, and the horizontal plate portion is used for inserting the vertical foil portions 2a of the vertical column main reinforcements 1 and bent column main reinforcements 2. Holes 11a are formed, and recesses 11b are formed at the upper edge of the vertical plate portion to fit with the main beam reinforcements 9 at the upper end. The beam support members 11 are supported by nuts 12 screwed to the vertical column main reinforcements 1 at the four corners, and the vertical column main reinforcements 1 and bent column main reinforcements 2...
It is not fixed to the This is done in consideration of not interfering with the free movement of the vertical column main reinforcements 1... and the bent column main reinforcements 2... during reinforcement work.

13 is column concrete, 14 is beam concrete, 15 is shear wall concrete, and 16 is wall reinforcement. 5b is a reinforcing rib for increasing the rigidity of the columnar reinforcement fixing plate 5.

According to the above-mentioned reinforcement arrangement structure, the vertical foil portions 2a of the vertical column main reinforcements 1 and the bent column main reinforcements 2 are attached to the column reinforcement fixing plate 5 having the horizontal pressure receiving surface S, and each pair of oak bars sandwiching the plate 5. ) 6a and 6b, in the event of an earthquake, tensile forces in opposite directions are alternately and repeatedly applied to the column main reinforcements (vertical column main reinforcements 1 and vertical foil portions 2a) on both the left and right sides of the column-beam joint section 3. However, the concrete bearing pressure by the column reinforcement fixing plate 5 prevents the column main reinforcement from slipping against the concrete of the column-beam joint part 3, and the proof strength of the X-shaped reinforcement does not decrease.

Next, Fig. 5 (a) shows the construction method for the above-mentioned reinforcement structure.

The explanation will be based on (b) and (c).

First, as shown in Figure 5 (a), beam reinforcing bars 8 and column reinforcing bars 1 are
Assemble the reinforcing bar assembly unit (A) consisting of 7 and lift it using a tow truck, etc. The column reinforcing bars 17 are the vertical column main bars 1...
, the bent column main reinforcement 2 . . . , the column reinforcement fixing plate 5 , the hoop reinforcement 7 , the beam support are constituted by the members 11 .

The beam reinforcing bars 8 and the column reinforcing bars 17 may be manufactured first, but when the beam main reinforcements 9... and the stirrups 10 are fixed by welding, the beam reinforcing bars 8 are manufactured first as described below. It is desirable to manufacture the reinforcing bar pre-assembled unit A by incorporating the column reinforcing bars 17 into this.

First, after manufacturing the beam reinforcement 8, the column reinforcement fixing plate 5 is placed between the upper and lower beam main reinforcements 9, and the column reinforcement fixing plate 5 is
Insert the vertical column main reinforcement 1 and the bent column main reinforcement 2 into the through-hole 5a, and slightly loosen each pair of nuts 6a and 6b screwed into them. In other words, the vertical column main reinforcement 1 and the bent column main reinforcement 2 are integrated with the column reinforcement fixing plate 5 via the nuts 6a and 6b, and the nut 6a.

Each of the vertical column main reinforcements 1 and the bent column main reinforcements 2 are connected so as to be movable in both the vertical and horizontal directions independently of each other within the range of the gap between the holes 6b and the accommodating gap with the through hole 5a.

The spiral hoop reinforcements 7 in a reduced state are fitted around the vertical column main reinforcements 1 and suspended from the column reinforcement fixing plate 5 with wires or the like.

In addition, with the nuts 12 screwed into the predetermined positions of each vertical column main reinforcement 1, the beam receiver inserts the vertical foil portions 2a of the vertical column main reinforcement 1 and bent column main reinforcement 2 into the blank holes 11a of the member 11. , the beam support allows the member 11 to be supported by the nut 12.

Sleeve 4a and lock nut 4b forming mechanical joint 4
are also screwed onto the ends of the vertical column main reinforcement 1 and the bent column main reinforcement 2 at an appropriate time.

After the reinforcing bar pre-assembled unit A is assembled in this manner, a suspension wire is hung around the beam reinforcing bars 8, and the reinforcing bar pre-assembled unit A is lifted up. In this state, the beam main reinforcement 9 at the lower end
... are in contact with the lower surface of the columnar reinforcement fixing plate 5. Further, displacement of the beam reinforcing bars 8 in the beam main reinforcing direction with respect to the column reinforcing bars 17 is prevented by the contact between the spiral stirrup 10 and the column reinforcing plates 5, the vertical column main reinforcing bars 1, etc.

Next, with the reinforcing bar assembly UNISO) A suspended and supported, the lower ends of the vertical column main reinforcement 1 and the lower ends of the bent column main reinforcement 2 are connected to the vertical column rising from the underground beam, as shown in Fig. 5 (b). It is connected in this order to the column main reinforcement 1, the bent column main reinforcement 2, the previously constructed vertical column main reinforcement 1 and the bent column main reinforcement 2, etc. on the lower floor, using a lock nut type mechanical joint 4. In this case, oak)
6a and 6b are loosened, and the vertical column main reinforcements] and bent column main reinforcements 2 are free to move within a certain range, so the phase of the threads of the column main reinforcements to be joined can be aligned, and the sleeve 4
This allows the joint between the lock nut 4b and the lock nut 4b to be performed without any problem.

Thereafter, as shown in FIG. 5(c), the spiral hoop reinforcements 7 are stretched and fixed to the vertical column main reinforcements 1 with binding wires or the like.

Then, after correcting the verticality of the vertical column main reinforcement 1 and the positional relationship of the bending point between the vertical moving part 2a and the upper and lower diagonal reinforcements 2b and 2c of the bent column main reinforcement 2 with respect to the column beam joint part 3, etc. ,
Tighten each oak (Ha, 6b) and complete the reinforcement work for the columns. Note that the beam reinforcing bars 8 are lowered to the original beam reinforcing bar position after the vertical column main reinforcing bars 1 and bent column main reinforcing bars 2 are connected, preferably after the hoop reinforcing bars 7 are fixed, and then lowered to the original beam reinforcing bar position and attached to the upper end beam. The main reinforcements 9... are supported by the beam supports on the members 11....

In the above embodiment, one direction has a rigid frame structure,
Since this is a building with a shear wall structure in the direction perpendicular to this, the bent column main reinforcement 2 is placed in a planar manner (flat in the beam direction) as shown in the diagram.
However, in the case of a building with a rigid frame structure in both directions, the reinforcement should be arranged to form a three-dimensional X shape, as shown in Figure 6. be. Also, although not shown, if the vertical column main reinforcements 1 are connected with each other using a mechanical joint 4 of the lock type, the reinforcing bar pre-assembled uni-nod A can stand on its own, so the bent column main reinforcements 2... The joints may be simply a lap joint by lengthening the bent column main reinforcements 2 by the amount of overlap.

〔Effect of the invention〕

The effects of the present invention are as follows.

Since the vertically moving parts of the vertical column main reinforcement and the bent column main reinforcement are fixed to the column reinforcement fixing plate having a horizontal pressure-receiving surface by a pair of nuts 6a and 6b that sandwich the plate,
During an earthquake, even if tensile forces in opposite directions are repeatedly applied to the column main reinforcements (vertical column main reinforcement 1 and vertical moving part 2a) on both the left and right sides of the column and beam joints, the concrete bearing pressure by the column reinforcement fixing plate is maintained. This prevents the column main reinforcing bars from slipping against the concrete at the column and beam joints, and the inherent strength of the X-shaped reinforcement arrangement does not decrease.

The vertical column main reinforcements at the four corners and the bent column main reinforcements arranged in an X shape between them are connected to a column reinforcement fixing plate and nuts 6a, 6.
Even if pre-assembled via b, nut 6a.

When 6b is loosened, the vertical column main reinforcement and bent column main reinforcement can freely move in all directions within a certain range,
It is possible to match the phase of the threads, and therefore, a lock nut type mechanical joint is used as a means of joining the column main reinforcements, eliminating the change (reduction) in the main reinforcement length that occurs when gas pressure welding is performed. When the nuts 6a and 6b are loosened, it is possible to correct the verticality of the vertical column main reinforcement and the vertical position of the bending point between the vertical moving part and the upper and lower diagonal reinforcement in the bent column main reinforcement. This allows reinforcement to be placed easily and accurately.

[Brief explanation of the drawing]

1 to 4 show one embodiment of the present invention, in which FIG. 1 is a front view of the reinforcement structure of an RC column, FIG. 2 is a cross-sectional plan view of the same, FIG. 3 is a perspective view of the same, and FIG. Figure 4 is a side view of the main part, and Figures 5 (a), (b), and (c) are front views showing an example of the construction method. FIG. 6 is a plan view showing another embodiment of the present invention. 7 and 8 are a front view and a plan view showing a conventional example. A... Reinforcing bar pre-assembly unit, 1... Vertical column main reinforcement, 2...
...Bent column main reinforcement, 2a...Vertical moving part, 2b...Upper diagonal reinforcement, 2c...Lower diagonal reinforcement, 5...Plate for fixing column reinforcement, 6a. 6b...nut, 7...hoop muscle. Figure 6 Figure 7

Claims (1)

[Claims] In a side view, the bent column main reinforcement consists of a vertical reinforcement part corresponding to the column-beam joint part, and an upper diagonal reinforcement and a lower diagonal reinforcement bent diagonally from both ends of the vertical reinforcement part, between the vertical column main reinforcements at the four corners. An RC column reinforcement structure in which reinforcement is arranged so as to form a shape, and hoop reinforcement is wrapped around the vertical column main reinforcement group, wherein the vertical column main reinforcement and the bent column main reinforcement are each threaded reinforcing bars, A column reinforcement fixing plate is provided in the vertical center of the column-beam joint part, and is formed in a rectangular ring shape in plan view and has a horizontal pressure-receiving surface. is inserted into the through hole formed in the columnar reinforcement fixing plate, and is inserted into the columnar reinforcement fixing plate by each pair of nuts screwed into the threaded joints of the threaded reinforcing bars. A reinforcement structure for RC columns using X-shaped reinforcement, which is characterized by being fixed in a state where it is sandwiched from both the upper and lower sides.