JP3850099B2 - Reinforcing existing structures - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for partially reinforcing an existing structure using a reinforcing material in which a high-strength fiber is formed into a sheet shape or a plate shape.
[0002]
[Prior art]
Conventional methods for reinforcing existing structures such as buildings are disclosed in, for example, Japanese Patent Publication No. 4-77104, Japanese Patent Application Laid-Open No. 9-53328, Japanese Patent Application Laid-Open No. 9-53329 (Int.Cl.E04G 23/02), and the like. As described above, there is one in which existing beams and columns are reinforced by a reinforcing material in which high-strength fibers are formed in a sheet shape.
[0003]
Here, {circle around (1)} the reinforcing method disclosed in the above Japanese Patent Publication No. 4-77104 is the second method toward the side surface of the beam so as to overlap the first reinforcing sheet attached to the bottom surface of the beam. A reinforcement sheet is attached. (2) In the reinforcing method shown in the above Japanese Patent Laid-Open Nos. 9-53328 and 9-53329, the bottom surface and both side surfaces of the beam are surrounded by a reinforcing sheet, and both ends of the reinforcing sheet are The angle member is sandwiched between angle members, and the angle member is fastened through bolts that penetrate the floor slab and bolts that penetrate between both side surfaces of the beam.
[0004]
However, in the method of (1) above, it is difficult to obtain a sufficient fixing effect on the reinforcing sheet on the bottom surface of the beam even if the reinforcing sheets are simply stacked and pasted. In this case, it is extremely difficult to penetrate the floor slab and the beam with high precision by using the method of fixing the both ends of the reinforcing sheet with the angle members fastened by the bolts passing through the floor slab and the beam, respectively. Is difficult to insert into the mounting hole formed in the angle member, and the mounting workability is inferior.
[0005]
Therefore, as a method of improving the fixing performance of the reinforcing sheet with relatively good mounting workability, the fixing plate 3 is disposed on the outer surface side of the reinforcing sheet 2 attached to the bottom surface 1a of the beam 1 as shown in FIG. There is one in which both ends of the fixing plate 3 are fastened by long bolts 5 and 5 that pass through a floor slab 4. In this case, the through hole 4 a of the floor slab 4 that penetrates the long bolt 5 is formed as a tapered hole that is expanded in diameter upward, and the long bolt 5 is allowed to swing to the fixing plate 3. The installation work is simplified.
[0006]
Therefore, in this reinforcing method, the fixing plate 3 is fastened by the long bolts 5 and 5, and the fixing sheet 3 is pressed against the bottom surface 1 a of the beam 1 by the fixing plate 3 to improve the fixing property of the reinforcing sheet 2. It can be done.
[0007]
[Problems to be solved by the invention]
However, the conventional reinforcing method using the fixing plate 3 has a structure in which the fixing plate 3 is brought into direct contact with the reinforcing sheet 2, so that the fixing plate 3 is curved by tightening the long bolt 5. In such a case, a uniform surface pressure cannot be applied to the entire surface of the reinforcing sheet 2, and the fixing property of the reinforcing material is deteriorated. Moreover, it is difficult to drill the through-hole 4a for penetrating the long bolt 5 in the floor slab 4, and it is necessary to repair the peripheral edge of the drilled through-hole 4a, and the operation is remarkably complicated. Further, the upper end portion of the long bolt 5 protrudes upward from the floor slab 4 and is locked via the seat plate 6 and the nut 5a, but the upper end portion of the long bolt 5 protruding from the floor slab 4 is It gets in the way. Furthermore, there are various problems that the long bolt 5 may be loosened over time after the vibration of the floor slab 4 is input, and the fixability of the reinforcing material may be reduced.
[0008]
Therefore, in view of the conventional problems, the present invention increases the reinforcing strength by adding a surface pressure substantially uniformly to the entire surface of the reinforcing material pasted on the reinforcing surface while improving the mounting workability. An object of the present invention is to provide a method for reinforcing an existing structure that can maintain the fixing property of the existing structure.
[0009]
[Means for Solving the Problems]
In order to achieve this object, the method for reinforcing an existing structure according to the present invention as described in claim 1 is a fixing method in which a sheet-like or plate-like reinforcing material is pasted on the bottom of an existing reinforced concrete beam and divided into upper and lower parts. The fixing portion, which is the upper portion of the fixture, is fixed to both side surfaces of the existing beam by anchor bolts, and an elastic body is disposed on the lower surface of the reinforcing material, while the supporting portion is the lower portion of the fixing jig. Supporting the lower side of the elastic body, applying a predetermined compressive force to the elastic body between the support portion and the reinforcing material, and fastening and connecting the support portion and the fixed portion via a flange It is fixed.
[0010]
The structure of the present invention shown in claim 2 is a reinforced concrete beam, a sheet-like or plate-like reinforcing material affixed to the bottom surface of the beam, and a fixing jig that is divided into upper and lower parts. A fixing jig having an upper portion fixing portion and a lower portion supporting portion, and an elastic body, and the fixing portions are fixed to both side surfaces of the beam by anchor bolts. The portion is disposed on the lower surface of the reinforcing material with an elastic body interposed therebetween, and the supporting portion and the fixing portion apply a predetermined compressive force to the elastic body between the supporting portion and the reinforcing material. However, it is characterized by being fastened and fixed via a flange.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
The operation of the reinforcing method of the existing structure according to the present embodiment will be described below. The outer surface of the reinforcing material pasted on the reinforcing surface of the existing structure can be pressed by an elastic body interposed between the fixing jig. Therefore, even when distortion occurs in the fixing jig, it is possible to apply a uniform surface pressure to the reinforcing material via the elastic body, and thus, the fixing property of the reinforcing material can be greatly improved. . In addition, since the elastic body can apply a surface pressure to the reinforcing material, it is not necessary to apply a pressing force directly to the reinforcing material by the fixing jig itself. For this reason, it is only necessary to support the fixing jig on an existing structure, and as a result, the structure of the supporting part of the fixing jig can be simplified, thereby facilitating and reducing the processing work on the existing part, And generation | occurrence | production of an obtrusive protrusion part can be eliminated as much as possible. Furthermore, since the vibration input to the fixing jig can be absorbed by the elastic body, it is possible to prevent the loosening of the support portion of the fixing jig as much as possible.
[0012]
In addition, when the reinforcing surface is the bottom surface of an existing beam, a fixing jig formed in a U shape along the bottom surface and both side surfaces of the existing beam is disposed with an elastic body on the outer surface of the reinforcing material. Therefore, both ends of the fixing jig can be attached to anchor bolts that are implanted on both side surfaces of the existing beam. Therefore, the elastic member can apply a uniform surface pressure to the reinforcing material and absorb the input vibration, and the fixing jig can be supported by the implanted bolts on both sides of the existing beam. The floor slab at the upper end does not require complicated processing such as through holes, and the workability for attaching the fixing jig can be greatly simplified, and an obtrusive protrusion is provided on the top surface of the floor slab. It will never be done.
[0013]
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. 1 and 2 show an embodiment of a method for reinforcing an existing structure according to the present invention. FIG. 1 is a sectional view of the reinforcing portion, and FIG. 2 is a front view of the reinforcing portion. In the present embodiment, a case where a beam of an existing structure is used as a reinforcing portion will be described as an example.
[0014]
That is, as shown in FIGS. 1 and 2, the reinforcing method of the existing structure of the present embodiment is a fixing method of the reinforcing sheet 11 pasted as a reinforcing material on the bottom surface 10a of the existing beam 10 made of reinforced concrete. A fixing jig 12 and a coil spring 13 as an elastic body are used. Here, the reinforcing sheet 11 is obtained by processing high-strength fibers such as carbon fibers into a sheet or plate shape, and the reinforcing sheet 11 is attached to the bottom surface 10a with an adhesive such as an epoxy resin. Yes. The fixing jig 12 is made of a steel plate or FRP (fiber reinforced resin) plate having a predetermined width w along the extending direction of the beam 10, and the bottom surface 10a of the existing beam 10 and its both side surfaces 10b and 10c. And bent into a U shape along the line.
[0015]
The fixing jig 12 is divided into upper and lower parts, the lower part is a supporting part 12a of the spring 13, and the upper part is a fixing part 12b to the existing beam 10. The support portion 12a and the fixed portion 12b are fastened and coupled with bolts and nuts via a flange 12c so as to be detachable. The fixed portion 12b is firmly fixed by tightening a nut 14a to an anchor bolt 14 planted in the vicinity of the upper ends of both side surfaces 10b and 10c of the existing beam 10.
[0016]
When the existing beam 10 is reinforced, the reinforcing sheet 11 is attached to a place where the bottom surface 10a of the existing beam 10 needs to be reinforced, and the fixing portion 12b of the fixing jig 12 is fixed to the anchor bolt 14. It fixes to the upper part of the both side surfaces 10b and 10c of the existing beam 10 via. Thereafter, the coil spring 13 is disposed on the lower surface of the reinforcing sheet 11, and the lower side of the coil spring 13 is supported by the center portion of the support portion 12a of the fixing jig 12, and the support portion 12a and the fixed portion 12b are supported. Are fastened and fixed via a flange 12c. In the fixing jig 12, the interval δ provided between the center portion of the support portion 12a and the reinforcing sheet 11 is set so that a predetermined compressive force can be applied to the coil spring 13. Needless to say.
[0017]
Therefore, in the reinforcing method of the present embodiment, the coil spring 13 is interposed between the reinforcing sheet 11 attached to the bottom surface 10a of the existing beam 10 and the fixing jig 12 in a compressed state. The reinforcing sheet 11 can be pressed and fixed by the compression force of the spring 13. For this reason, the pressing force of the coil spring 13 acts on the reinforcing sheet 11, and even when the support portion 12 a of the fixing jig 12 is bent or the like is distorted, it is almost affected by this. It is possible to apply the uniform surface pressure by pressing the reinforcing sheet 11 without any problem. Accordingly, the fixing property of the reinforcing sheet 11 can be remarkably improved, and the strength of the existing beam 10 can be greatly increased, thereby improving the earthquake resistance.
[0018]
Further, since the surface pressure can be applied to the reinforcing sheet 11 by the coil spring 13, it is not necessary to generate a pressing force to the reinforcing sheet 11 directly on the fixing jig 12 itself. For this reason, the fixing jig 12 is simply supported by the existing structure side, that is, the existing beam 10 in this embodiment, and can be locked to the anchor bolts 14 planted on both side surfaces 10b and 10c of the existing beam 10. it can. Thus, since the anchor bolt 14 can be easily planted by drilling and driving into the existing beam 10, the structure of the support portion of the fixing jig 12 can be simplified. Further, the floor slab (not shown) constructed at the upper end of the existing beam 10 does not require complicated processing such as a through hole, and the structure for supporting the fixing jig 12 is greatly simplified, It is possible to improve the performance, and there is no disturbing protruding portion on the upper surface of the floor slab.
[0019]
Further, even when vibration is input to the fixing jig 12 from the existing beam 10 side, the coil spring 13 can absorb the vibration, so that the support portion of the fixing jig 12 is loosened. Can be prevented as much as possible, and the fixing strength of the reinforcing sheet 11 can be maintained for many years.
[0020]
In the present embodiment, the coil spring 13 is used as the elastic body. However, it is more preferable to use a leaf spring having higher rigidity and less spring instead of the coil spring 13. In addition, a plurality of elastic bodies using the coil springs 13 or leaf springs are arranged in the width direction or the length direction of the existing beam 10 between the reinforcing sheet 11 and the fixing jig 12 in this way, and the fixing jig By changing the respective spring constants according to the 12 strain shapes, a more uniform surface pressure can be applied to the reinforcing sheet 11. Further, the fixing jig 12 is divided into a support portion 12a and a fixed portion 12b for easier mounting workability. However, the fixing jig 12 may be formed integrally as a whole and directly supported by the anchor bolt 14. Of course.
[0021]
By the way, in the present embodiment, the method for reinforcing the existing beam 10 has been described as an example. However, the present invention can be applied to the reinforcement of the lower surface of the floor slab. In this case, an elastic body is provided at the center of the fixing jig. For example, a steel plate may be formed in a hat shape having flanges on both side ends thereof, and both ends of the fixing jig may be fixed to the lower surface of the floor slab with planting bolts.
[0022]
Moreover, although the above-mentioned embodiment described the existing structure of reinforced concrete structure, this invention is applicable also to the existing structure of steel structure. In other words, a reinforcing sheet is attached to a place to be reinforced, such as a steel beam or a steel column, and the fixing jig for fixing the reinforcing sheet is fastened with a nut to a stud bolt welded to the column or beam. good.
[0023]
【The invention's effect】
As described above, in the method for reinforcing an existing structure shown in the embodiment of the present invention, the outer surface of the reinforcing material attached to the reinforcing surface of the existing structure is placed between the fixing jig that supports the existing structure. Since it can be pressed by the interposed elastic body, even when the fixing jig is distorted, it is possible to apply a uniform surface pressure to the reinforcing material via the elastic body. Fixability can be greatly improved. Further, since the elastic body applies a surface pressure to the reinforcing material, it is not necessary to directly apply a pressing force to the reinforcing material by the fixing jig itself. For this reason, it is only necessary to support the fixing jig on an existing structure, and as a result, the structure of the supporting part of the fixing jig can be simplified, thereby facilitating and reducing the processing work on the existing part, And generation | occurrence | production of an obtrusive protrusion part can be eliminated as much as possible. Furthermore, since the vibration input to the fixing jig can be absorbed by the elastic body, it is possible to prevent loosening of the support portion of the fixing jig as much as possible, and for many years. The reinforcing strength can be maintained.
[0024]
Further, in the method for reinforcing an existing structure shown in the embodiment of the present invention, the reinforcing surface is used as the bottom surface of the existing beam, and a fixing jig formed in a U shape along the bottom surface and both side surfaces is reinforced. Since the elastic body can be disposed on the outer side surface of the material, both ends of the fixing jig can be attached to anchor bolts implanted on both side surfaces of the existing beam. Therefore, it is possible not only to apply a uniform surface pressure to the reinforcing material by the elastic body and to absorb the input vibration, but also to eliminate complicated processing such as a through hole in the floor slab of the existing beam upper end, The construction workability for attaching the fixing jig can be greatly simplified, and various excellent effects can be achieved in that it is possible to prevent an obtrusive protruding portion from being provided on the upper surface of the floor slab.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a reinforcing portion showing an embodiment of a method for reinforcing an existing structure according to the present invention.
FIG. 2 is a front view of a reinforcing portion showing an embodiment of the present invention.
FIG. 3 is a cross-sectional view of a reinforcing portion showing a conventional reinforcing method.
[Explanation of symbols]
10 Existing beam 10a Bottom surface 11 Reinforcement sheet (reinforcement material)
12 Fixing jig 13 Coil spring (elastic body)
14 Anchor bolt

Claims (2)

Paste a sheet-like or plate-like reinforcement on the bottom of an existing reinforced concrete beam,
Fix the fixed part, which is the upper part of the fixing jig divided into upper and lower parts, on both sides of the existing beam with anchor bolts,
While placing an elastic body on the lower surface of the reinforcing material, supporting the lower side of the elastic body with a support portion which is a lower side portion of the fixing jig,
An existing construction characterized by fastening and fixing the support portion and the fixing portion via a flange while applying a predetermined compressive force to the elastic body between the support portion and the reinforcing material. Reinforcement method. Reinforced concrete beams,
A sheet-like or plate-like reinforcing material affixed to the bottom of the beam;
A fixing jig that is divided into upper and lower parts, a fixing jig having a fixed part that is an upper part and a support part that is a lower part,
With an elastic body,
The fixed portion is fixed to both side surfaces of the beam by anchor bolts;
The support portion is disposed with an elastic body on the lower surface of the reinforcing material,
The support portion and the fixed portion are fixedly connected by fastening via a flange while applying a predetermined compressive force to the elastic body between the support portion and the reinforcing material. Structure.

Images