JP4942475B2 - Reinforcement method and structure of existing columns - Google Patents

Description

  The present invention relates to a method for reinforcing an existing column and a reinforcing structure, and more particularly to a method for reinforcing an existing column that can prevent the brittle destruction of a column and increase the earthquake resistance of the building in order to increase the rigidity and proof strength of the building. Reinforcing structure.

Conventionally, in order to increase the rigidity and proof strength of a building, a seismic wall is often added, but the existing columns are reinforced by the following method.
a, Restraint reinforcement method in which the periphery of a pillar is covered with a steel plate or fiber.
b, Cross section increasing method to increase the cross section by increasing the concrete.
c, Steel material integration method in which steel plates and shaped steels are attached to columns and integrated by bolts, studs, and grouts.
d, Sleeve wall extension method to add sleeve walls adjacent to pillars.

The sleeve wall expansion method is a building where the load bearing capacity of the shear failure type column is large, the beam bearing strength is sufficient, and it can be expected that the possessing strength of the entire building will be sufficiently increased by increasing the column bearing strength. Applies to The above-mentioned sleeve wall expansion method (prior art 1) shown in FIGS. 5 and 6 is provided with strength by partially closing the opening and expanding the sleeve wall in the direction extending from the center of the column to both sides. Although the rigidity can be increased, the conventional method generally performed includes the following steps.
d-1 A step of making a hole in the pillar 2, the beam 3, the lower floor beam 4, and the slab and driving the anchor bar 22 to fix it.
d-2 A step of assembling the form frames (not shown) on both sides of the reinforcing bar set after assembling the vertical and horizontal reinforcing bars 11 and 12.
d-3 A step of placing concrete, curing it, and demolding.

As described above, the sleeve wall expansion method that has been generally performed is not as large as the earthquake-resistant wall expansion work, but the construction period is prolonged, and during the construction period, for example, drilling when anchor bars 22 are driven. Use of buildings is greatly restricted by vibrations and noise from drills, dust from drilling, etc. Especially when carrying out reinforcement work while using buildings such as office buildings, hospitals, hotels, condominiums, etc. There is a problem of causing significant obstacles to recreation and daily life.
In addition, when the sleeve wall 6 is extended in the direction extending from the center of the column, since 11 and 12 are arranged in both front and back, the number of anchor bars is increased, and the above noise is long. There is also a problem that it occurs over a long period of time.

Further, in the reinforcing method of the existing column shown in FIG. 7 (Prior Art 2), the loop-shaped sleeve wall lateral stripes 24 are in the form of reinforcing bars, so that the reinforcing bars are inserted at two locations on the front and back of the existing columns 2. It is necessary to drill through holes.
For this reason, this sleeve wall reinforcing method has a problem that noise for perforation is generated for a long time and the construction period is prolonged as compared with the prior art 1.

  Furthermore, there is a method (prior art 3) in which the sleeve wall shown in FIG. 8 is shifted to one of the front and back surfaces of the existing pillar, and this method also requires the anchor bar 22 to be installed. The concrete surface on either the front or back side of the pillar 2 is suspended until the strip 14 is exposed, and the reinforcing bar 24 is placed to increase the concrete 27 including one side of the existing beam. In the construction period, the use of the building is greatly restricted, and there is a problem common to the above-described sleeve wall expansion method in that vibration and noise are generated when anchor bars are placed.

Furthermore, as in the existing column reinforcing method disclosed in Japanese Patent Laid-Open No. 11-336252 (refer to Prior Art 4 and FIG. 9), the above-mentioned restraint reinforcing method and d sleeve wall expansion method are combined. Then, after the sleeve wall is partially precast and the flat U-shaped steel plate 28 to which the anchor bars 22 are fixed with bolts is wound around the pillar, the U-shaped steel plate 28 is joined by the carbon fiber connecting material 29, and the PC sleeve wall There has been proposed a column reinforcing method in which a joint between a column and a sleeve wall is devised so that a non-shrink mortar is filled in a gap between the junction groove 30 and the existing column 2 and the U-shaped steel plate 28.
The column reinforcing method disclosed in the above publication uses a large-sized and heavy dissimilar member, so it is difficult to actually construct it while using a building, and there are many processes. Is difficult.
JP-A-11-336252

  The present invention was devised in view of the above problems, shortening the construction period by simplifying the construction content, eliminating or reducing the post-installed anchor bars as much as possible, and using the building It aims at providing the reinforcement method and reinforcement structure of the existing pillar which can implement.

The invention according to claim 1 is a reinforcing structure in which sleeve walls are added to the left and right sides of the existing pillar, and includes two vertical ribs that are parallel to the existing pillar width while studs are driven into the sleeve wall body side, One or a vertically divided flat plate-like steel plate that the vertical rib abuts on both side surfaces of the existing column and is fixed to one of the right and left sides of the existing column and extends to the left and right sides thereof , wall muscle in the side concrete does not include the steel sheet of the left and right sides of the existing columns are pouring a mold without demolding the steel plate and the said sleeve wall body of reinforced concrete that are single Haisuji, the existing Reinforced structure of existing pillars integrated through pillars.

According to the first aspect of the present invention, the construction method can be simplified, the anchor construction can be minimized or minimized, and the generation of noise during the construction period can be suppressed as much as possible. to shorten the construction period compared to, moreover, Ru can be carried out reinforcement work of the existing posts while using the building.
Furthermore, since the vertical ribs are in contact with the left and right sides of the existing column and sandwich both sides of the column, the force of the steel plate can be transmitted to the existing column. It can contribute to the integration into the pillar.

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 is a partial elevational view of a building in which a part of a building frame 1 is partially longitudinally cut, wherein 3 is a beam, 4 is a lower floor beam, 7 is a leaning wall, and 8 is a waist wall.
5 is one sheet attached to one side of the existing pillar shown in FIGS. 2 and 3 and extending to the left and right sides thereof, and fixed to one side of the sleeve wall as a formwork or a structural material that also serves as a formwork The steel plate 9 having a plate-like rigidity is a sleeve wall that is added to the existing column and is integrated with the reinforced concrete sleeve wall body on both the left and right sides of the existing column.
In the form of this additional sleeve wall 5, the upper and lower ends of one flat steel plate 9 are attached to either the front wall or the back surface of the leaning wall 7 and the waist wall 8 on the left and right sides of the existing column 2 and beam 3. However, the upper and lower ends of the reinforced concrete sleeve wall main body of the additional sleeve 5 are integrated with the lower end of the leaning wall 7 and the upper end of the waist wall 8 at the height position indicated by the broken line in FIG. In some cases, the steel plate may be bonded to the waist wall or the leaning wall with a resin or the like.

  Reference numeral 6 shown in FIG. 1 indicates another embodiment of the additional sleeve wall, and one flat steel plate 9 of the additional sleeve wall 6 and the upper and lower ends of the sleeve wall body are aligned. The upper and lower ends are integrated with the lower end of the leaning wall 7 and the upper end of the waist wall 8.

Whether one flat steel plate 9 is attached to any side of the existing pillar 2, for example, the indoor side or the outdoor side when the existing pillar 2 is located on the outer periphery of the building, depends on the exterior of the building and the work. It is determined by comprehensively judging the ease of use, hindrance to daily use of the building, and the effect of reinforcement.
When the building has a leaning wall 7 or a waist wall 8, whether the upper and lower parts of the steel plate 9 are attached to the side surfaces of the leaning wall 7 and the waist wall 8 depends on whether the waist wall or the leaning wall is a pillar. It is determined according to the position where it is installed. That is, for example, when the indoor surfaces of the existing pillars and the leaning wall and the indoor surface of the waist wall are flush, if the steel plate is attached to the leaning wall and the waist wall, the indoor area is reduced, so that it is avoided as much as possible. In this case, as indicated by reference numeral 6 in FIG. 1, the steel plate is preferably sandwiched between the leaning wall and the waist wall.
Further, when it is desired to increase the reinforcement strength and deformation performance, the wall may be struck against the waist wall or the leaning wall integrally with the sleeve wall that closes the opening.

[Embodiment 1]
The first embodiment of the present invention will be described in detail with reference to FIG.
In this figure, 2 is an existing column, 13 is an existing column main reinforcement, and 14 is an existing column strip, and the column wall 5 is added to the left and right sides of the existing column 2 to reinforce the column.
The construction method of this additional sleeve wall 5 is demonstrated.
On one side, excluding the portion corresponding to the surface of the existing column 2, one a single steel plate 9 having rigidity that Da設stud 10 at predetermined intervals in the horizontal and vertical directions of the one of the rear or front of the existing columns 2 Build along the surface and fix to the existing pillar 2.
As a method for fixing one flat plate-like steel plate 9 to the existing column 2, it may be only fixed with a temporary fixing bolt, but it is preferable to bond using an epoxy resin adhesive or the like.
A wall bar composed of a horizontal bar 11 of the overhanging length of the sleeve wall 5 on one side and a vertical bar 12 of the opening height or the inner floor height is pre-assembled at a predetermined interval. 11 and 12 are set on the left and right sides of the existing pillar 2 and at positions adjacent to the one flat steel plate 9.
In addition, if there is no suitable place for pre-assembling the wall bars, they may be assembled on site.
Further, in this embodiment, a single flat steel plate 9 that is later integrated with reinforced concrete serves as a substitute for the wall bars 11 and 12, so a single bar arrangement may be used.
Further, the step of fixing the steel plate to the existing column and the step of setting the pre-assembled wall reinforcement at a predetermined position are not necessarily performed in this order, and may be performed in the reverse order.
Furthermore, in this embodiment, the steel plate 9 is a single flat plate, but the steel plate 9 can be divided in the vertical direction to have a small area that is long in the horizontal direction. Workability such as installation can be improved. At this time, the plurality of divided long steel plates 9 are fixed to the surfaces of existing horizontal members such as the existing columns 2, beams 3, 4, waist wall 8, leaning wall 7 with temporary fixing bolts or epoxy. It adheres using resin adhesive etc., and it fixes to an existing pillar or an existing horizontal member in order from the bottom.
And this construction method is basically applicable to the structures of Embodiments 2 and 3 described later.

In this embodiment, since one steel plate 9 attached to one surface of the existing column 2 and extending on both sides thereof is integrated with the sleeve wall body via the existing column on both sides of the existing column, It is not always necessary to anchor the wall bars 11 and 12 to the column 2, the beams 3 and 4, and the floor as in the conventional method of reinforcing a column.
However, in order to increase the integrity of the building frame and the additional sleeve wall and ensure it, the horizontal bar 11 on the side of the additional sleeve wall 5 that does not have the steel plate is passed through the insertion bar or column using the post-installed anchor. It is effective to fix to the existing pillar 2 by a line or the like.
In addition, for the vertical bars 12 at the outer end of the extension sleeve wall 5, incisors using post-installed anchors are placed on the upper and lower surfaces of the beam, or the side surfaces of existing horizontal members such as beams, waist walls, and hanging walls. It is effective to prevent the additional sleeve wall 5 from curving in a convex shape on the side not provided with the steel sheet by hitting a short dowel line to fix the additional sleeve wall to the existing horizontal member.
The construction method and the constructed reinforcing structure for fixing these additional sleeve walls to the existing frame are also effective in the second and third embodiments to be described later.

Although not shown, the remaining mold frame including the other mold frame that is spaced apart from the steel plate 9 is assembled so that the wall bars are surrounded by the steel plate. This formwork is a conventionally used wooden formwork, and the overhanging length of the sleeve wall on one side is not less than 1/2 and not more than twice the length of the pillar of the existing pillar 2, and at least 50 cm.
Further, the thickness of the additional sleeve wall 5 is usually about 1/4 of the column width, and at least 15 cm.

Next, concrete or synthetic resin is filled or placed inside the entire formwork installed with one flat steel plate 9 and wooden formwork independently built on both sides of the existing pillar. To do.
If a gap remains under the beam or slab, it is desirable to inject grout later.
After the curing / molding period of concrete or synthetic resin has passed, only the wooden formwork is removed except for the steel plate, and the steel plate 9 is left as it is.

  By the above construction method, one steel plate 9 attached to one side of the existing column 2 and extending on both sides thereof, and a sleeve wall integrated with the steel plate 9 via the existing column on both sides of the existing column It is possible to construct a reinforcing structure in which sleeve walls are added on both sides of an existing pillar composed of a main body.

In the above description, the sleeve wall body of the additional sleeve wall 5 is described as being reinforced concrete, but the sleeve wall body is made of high-strength concrete having a compressive strength exceeding, for example, 100 Mpa, or made of steel or synthetic. If a fiber concrete structure mixed with resin fibers, or a synthetic resin structure with a high tensile strength such as an epoxy resin polymer or a cement-based material mixed with a synthetic resin is used, the sleeve wall body is free of reinforcing bars. It doesn't matter.
When such a structure is adopted, the additional sleeve wall 5 is prevented from curving in a convex shape on the side not provided with the steel plate, and the integration between the building frame and the additional sleeve wall is enhanced as described above. It is effective to anchor at the outer end of the.

  Further, in this embodiment, the stud 10 is driven into the sleeve wall main body side of the steel plate 5. However, instead of or in addition to this, a lateral rib may be provided. If it does in this way, the rigidity of steel plate 5 itself will be raised, a sleeve wall will be prevented from curving convexly to the side which does not have a steel plate, and an anchor effect will also increase by embedding a side rib in a sleeve wall main part.

[Embodiment 2]
This embodiment is shown in FIG. In this figure, the description of the same reference numerals as those in FIG. 2 is omitted, and only characteristic features are described.
Reference numeral 16 denotes a through-bar that penetrates the existing pillar 2 in the horizontal direction, 17 denotes a vertical rib, and 18 denotes a horizontal rib.
The vertical ribs 17 are made of angle steel, and one piece is welded and fixed to the flat steel plate 9, and the other piece is formed with dowel placement holes (not shown) at predetermined intervals. One flat steel plate 9 is fixed to both side surfaces of the existing pillar 2 by dowels.
In this embodiment, when the steel plate 9 is divided into those having a small area in the lateral direction, the vertical ribs 17 having holes for doweling and bolt insertion at predetermined intervals on both sides are provided with existing pillars. The steel plate 9 may be fixed to the existing column 2 by being fixed to 2 with dowel bars and bolted through bolt insertion holes corresponding to the insertion holes of the divided steel plates.
The thickness of the additional sleeve wall 5 is made thinner than that of the first embodiment.
On the other hand, the wall reinforcement of the reinforced concrete sleeve wall main body is composed of only the horizontal through bars 16 which penetrate the existing pillar 2 on the side not provided with the steel plate 9 and are arranged at predetermined intervals in the vertical direction.

Further, on the sleeve wall main body side of one flat plate-like steel plate 9, horizontal ribs 18 are provided with irregularities for increasing the adhesion to concrete on the surface at predetermined intervals in the vertical direction. Yes.
The number of the standing ribs 18 is not limited to the number of the horizontal reinforcing bars 16 arranged, and may be added between the corresponding height positions.

Further, on the sleeve wall main body side of the steel plate 9, two vertical ribs 17, 17 parallel to the width of the column of the existing column are provided, and the vertical rib is in contact with both side surfaces of the existing column 2.
And since this vertical rib 17 has a height of about 1/2 of the wall thickness of the additional sleeve wall 5, it abuts on both sides of the existing pillar 2 and sandwiches both sides of the pillar. 5 can be transmitted to the pillar 2 and contributes to the integration of the additional sleeve wall 5 into the existing pillar 2 in the same manner as the through-bar 16.

  Furthermore, also in this embodiment, if the longitudinal bars 12 and the anchor bars 22 are provided in the vicinity of both ends of the reinforced concrete sleeve wall 5, the sleeve wall protrudes to the side not provided with the steel plate, as in the first embodiment. It is possible to improve the integrity of the building frame and the additional sleeve wall.

[Embodiment 3]
This embodiment is applied to the sleeve wall 6 to be added to reinforce the pillar when walls are provided on the three faces of the existing pillar 2, that is, the existing pillar with the wall attached. The present invention relates to a reinforcing structure in which sleeve walls are added on the surfaces orthogonal to the walls on both sides of the wall.
Referring to FIG. 4, reference numeral 19 denotes two independent left and right steel plates that are attached to the existing pillar 2 with a wall 20 therebetween, and extends to both sides of the pillar, and 21 denotes two independent left and right sheets. For example, a flat connecting steel having a rectangular cross section is formed by connecting the steel plates 19 and 19 through the wall 20.
The cross-sectional shape of the connecting steel 21 may be any as long as it can penetrate the wall 20.

A large number of studs 10 are erected on the sleeve wall body side of the two steel plates 19, 19 attached to the existing pillar 2 via the wall 20, and the steel plate 19 and the sleeve wall body made of concrete, etc. Is ensured.
The connecting flat steel 21 is a flat steel plate having a width approximately twice as large as that of the existing pillar 2 and having an appropriate height and thickness. The connecting flat steel 21 is arranged at predetermined intervals in the vertical direction of the pillar, with a wall in between. The two steel plates 19 and 19 attached to the existing pillars are fixed by welding.
As is clear from FIG. 4, no reinforcing bars are arranged on the sleeve wall main body of the additional sleeve wall 6. In order to increase the tensile strength of the sleeve wall main body, the material is made of high-strength concrete whose compressive strength exceeds, for example, 100 Mpa, fiber cement mixed with steel or synthetic resin fibers, or epoxy resin polymer, for example. It is desirable to use a synthetic resin having a high tensile strength or a cement-based material mixed with a synthetic resin.

In order to enhance the unity between the building housing 1 and the expanded sleeve wall 6, it is also effective to provide the vertical ribs 17 and the horizontal ribs 18 as in the second embodiment.
In some cases, the method of fixing the additional sleeve wall to the existing housing and the constructed reinforcing structure described in paragraph 0015 are also effective in this embodiment.

1 is a partial elevation view of a building in which a part of a building frame 1 is partially cut vertically. It is a cross-sectional view of Embodiment 1 of this invention. It is a cross-sectional view of Embodiment 2 of the present invention. It is a cross-sectional view of Embodiment 3 of the present invention. It is a longitudinal cross-sectional view of the prior art 1. 1 is a cross-sectional view of prior art 1. FIG. It is a cross-sectional view of the prior art 2. It is a cross-sectional view of the prior art 3. It is a cross-sectional view of the prior art 4.

Explanation of symbols

1 Building frame 1
2 Existing pillar 2
3 Beam 3
4 Lower floor beam 4
5 Additional sleeve wall 5
6 Additional sleeve wall 6
7 Sacrificial wall 7
8 Waist wall 8
9 Steel plate 9
10 Stud 10
11 Side wall of sleeve wall 11
12 Longitudinal line of sleeve wall
13 Existing column mains 13
14 Existing column strip 14
15 L-shaped steel frame 15
16 Reinforcing bar 16
17 Vertical rib 17
18 Side rib 18
19 Two steel plates 19 attached to an existing pillar through a wall
20 Existing wall 20
21 Connecting flat steel 21
22 Anchor reinforcement 22
23 Splitting prevention muscle 23
24 Reinforcing bar 24
27 Reinforced concrete 27
28 Planar U-shaped steel plate 28
29 Carbon fiber connecting material 29
30 Joining groove 30

Claims (1)

It is a reinforcement structure with sleeve walls added to the left and right sides of the existing pillar,
Studs are driven into the sleeve wall body side and two vertical ribs parallel to the existing column width are provided, and the vertical ribs are in contact with both side surfaces of the existing column and fixed to one side of the existing column. A flat steel plate that is divided into one sheet or the vertical direction that extends to both the left and right sides;
Wall muscle in the side not provided with the steel plate of the right and left sides of the existing pillars steel plate concrete is pouring the mold without demolding the said sleeve wall body of reinforced concrete that are single Haisuji,
The reinforcement structure of the existing pillar integrated via the said existing pillar.

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