JPH10219928A - Earthquake-proof structure of concrete-made support - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance strength for buckling deformation and shorten an execution time by fixing a steel plate divided in the circumferential direction and disposed so as to surround the surface by an anchor bolt embedded in a concrete-made support. SOLUTION: With regard to a steel plate 14 divided into four parts and formed into a generally L-shaped cross section, a support 10 is covered, and a side edge part 14a forming a space part in a face direction from a corner part and folded in the form of a crank toward the inside is provided. A connection plate over the entire length of the steel plate 14 is abutted on the outer face side of the opposed side edge part 14a, and welded and fixed to be connected to a box shape. Anchor bolts 15 fixed by driving supports of epoxy resin into many holes drilled in the longitudinal direction of a concrete-made support 10 are inserted in through holes provided in the connection plate 16, nuts 17 are screwed, and pushed to the concrete made support 10. Thereby curvature deformation outward of the steel plate 14 is prevented, and strength of the concrete made support 10 for buckling deformation can be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seismic reinforcement structure for a concrete column such as a pillar of a house or a pier of a bridge.

[0002]

2. Description of the Related Art Conventionally, seismic reinforcement of concrete columns, such as pillars of houses and piers of bridges, is as shown in FIG.
Usually, four steel plates 2 are arranged on each surface of the concrete column 1, and side edges corresponding to the corners of the column 1 of these steel plates 2 are welded to each other to form the entire surface of the concrete column 1. This is done by covering.

[0003]

By the way, in the above-mentioned conventional seismic reinforcement structure, since the steel plates 2 are simply welded at the corners, the concrete columns 1 have insufficient strength against buckling. There is a problem, and since a plurality of steel plates 2 must be connected by welding, a welded portion is exposed on the surface, so that processing such as adjusting the shape of the welded portion is required, and the work becomes complicated. There are also problems.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has a sufficient strength against buckling, and has a seismic resistance of a concrete column which can omit a welding process. It is intended to provide a reinforcing structure.

[0005]

According to the first aspect of the present invention, in order to achieve the above-mentioned object, a steel plate is provided surrounding a surface of an existing concrete column. The steel plate is fixed via an anchor bolt planted on the concrete column.

According to a second aspect of the present invention, in the seismic reinforcement structure for a concrete column, the steel plate is divided into a plurality in the circumferential direction of the concrete column, and the side edges of these steel plates are set inside. It is bent in the shape of a crank toward each other and opposed at a predetermined interval, and connected to each other by welding connecting plates to their side edges, and fixing the connecting plates to the anchor bolts. Features.

According to a third aspect of the present invention, in the seismic reinforcement structure for a concrete column, the steel plate is divided into a plurality of portions in the circumferential direction of the concrete column, and the side edges of these steel plates are set inside. It is characterized in that it is bent in a crank shape and overlapped with each other, and this overlapped portion is fastened together with the anchor bolt.

[0008] In addition, the seismic reinforcement structure for a concrete pillar according to claim 4 of the present invention is described in claims 1 to 3.
Wherein a gap is provided between the concrete column and the steel plate, and the gap is filled with concrete or mortar.

Further, the concrete seismic reinforcement structure for a concrete pillar according to a fifth aspect of the present invention is characterized in that, in the fourth aspect, a stud bolt is projected from a back surface of the steel plate.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. Reference numeral 10 in FIG.
Shows a concrete strut to which the present embodiment is applied. The concrete strut 10 is provided with a plurality of main reinforcements 11 arranged in the longitudinal direction and surrounding these main reinforcements 11. Hoop streaks 12 provided at predetermined intervals in the length direction of the
And concrete 13 cast so as to include the hoop streaks 12.

In the seismic retrofit structure of the present embodiment applied to such a concrete column 10, a steel plate 14 is provided so as to surround the surface of the concrete column 10,
This steel plate 14 has a basic configuration in which the steel plate 14 is fixed via anchor bolts 15 planted on the concrete pillar 10.

Next, these details will be described.
In the present embodiment, the steel plate 14 is divided into four in the circumferential direction of the concrete pillar 10, and each has a substantially L-shaped cross-sectional shape so as to cover the pillar 10 from the corner side. The side edges 14a are bent inwardly in the shape of a crank, and these side edges 14a are butted at a substantially middle portion in the width direction of the surface of the concrete column 10 to thereby form the concrete column. The space 10 is formed so as to cover the whole of 10 and extend from the corner portion along the surface direction.

When the steel plates 14 are installed so as to cover the corners of the concrete column 10, the abutting portions of the side edges 14a face each other at a predetermined interval. A connecting plate 16 extending over the entire length of the steel plate 14 is brought into contact with the outer surface of the opposing side edge portion 14a.
6 are fixed to the side edges 14a by welding, so that the steel plates 14 are connected in a box shape.

Although not shown, the anchor bolt 15 is inserted into the concrete support 10 after driving a support made of epoxy resin into a hole formed in the concrete support 10, and is inserted into the support. It is fixed so as to protrude from the surface by a predetermined length. A large number of the anchor bolts 15 are provided at substantially the center of each surface of the concrete column 10 in the width direction at intervals of, for example, 30 cm in the length direction.

Further, through holes are formed in the connecting plate 16 at a pitch equal to the pitch at which the anchor bolts 15 are installed, and the anchor bolts 15 are inserted into these through holes. And the connecting plate 16 is connected to the concrete column 10 by a nut 17 screwed to the projection of each anchor bolt 15.
, The side edges 14 a of the steel plates 14 are pressed against the concrete columns 10.

Further, in the present embodiment, a plurality of stud bolts 18 are protruded from the inner surface of each of the steel plates 14,
A substantially U-shaped support member 19 is provided on the outer surface side of the connection plate 16 for each of the anchor bolt 15 and the nut 17.
Further, a cover 20 having a U-shaped cross section that covers the side edge portion 14a of the steel plate 14 over its entire length is screwed by the support members 19.

On the other hand, a space formed between each of the steel plates 14 and the surface of the concrete column 10 is filled with a non-shrinkable mortar 21.

According to the seismic reinforcement structure of the concrete strut 10 according to the present embodiment, the steel plates 14 are attached to the concrete strut 10 by the anchor bolts 15.
When the buckling load is applied to the concrete support 10 and the steel plate 14 is to be pushed and spread, the outward bending deformation of the steel plate 14 is prevented by the anchor bolt. By being blocked by 15, sufficient strength against buckling deformation of concrete column 10 is obtained.

Further, the non-shrinkable mortar filled between the surface of the concrete column 10 and the steel plate 14 is further reinforced, and the non-shrinkable mortar and the steel plate 14 are integrated by stud bolts 18. Therefore, these displacements are prevented, and the reinforcement against buckling is further enhanced from this point.

Further, the side edges 14a of the steel plate 14 are bent in a crank shape toward the inside, and these side edges 1a are bent.
4a was welded through the connecting plate 16, so that the welded portion was not exposed on the surface, and therefore,
Decoration processing such as painting can be directly performed without pre-processing, and the construction time is shortened.

The various shapes, dimensions, and the like of the components shown in the above embodiment are merely examples, and can be variously changed based on design requirements and the like. For example, as shown in FIG. 3, the side edges 14a of the steel plates 14 may be overlapped with each other, and the steel plates 14 may be fastened together by the anchor bolt 15 and the nut 17 penetrating the side edges 14a of the overlap. It is. With such a configuration, the connection plate 16 can be omitted, and the welding process is not required, thereby simplifying the configuration and construction.
In the present invention, a normal mortar or concrete may be used instead of the non-shrinkable mortar.
However, preferably, non-shrinkable mortar is used.

[0022]

As described above, according to the first aspect of the present invention,
According to the seismic retrofit structure of concrete struts related to
By integrating each steel plate into a concrete column with an anchor bolt, even if a buckling load is applied to the concrete column and the steel plate is about to be spread, the outward deformation of the steel plate is prevented by the anchor bolt. And the strength of the concrete column against buckling deformation can be increased.

According to the second embodiment of the present invention, in the first embodiment, the steel plate is divided into a plurality of pieces in the circumferential direction of the concrete column, and the side edges of these steel sheets are formed inside. Bending in the shape of a crank and facing each other at a predetermined interval, connecting them by welding a connecting plate to their side edges, fixing the connecting plate to the anchor bolt, The portion can be prevented from being exposed on the surface, and the pretreatment in the decoration process such as painting can be omitted to simplify the construction.

According to a third embodiment of the present invention, in the first embodiment, the steel plate is divided into a plurality of portions in the circumferential direction of the concrete column, and the side edges of these steel plates are formed inside. And bent together in the shape of a crank and overlapped with each other, and this overlapped portion is fastened together with the anchor bolts, minimizing the number of parts used when mounting the steel plate and eliminating the need for welding Accordingly, the configuration and construction can be simplified.

According to a fourth embodiment of the present invention, there is provided a concrete column having an earthquake-resistant structure, wherein a gap is provided between the concrete column and the steel plate. By having a structure filled with concrete or mortar, the area around the concrete column is reinforced with concrete or mortar,
The strength against buckling can be further increased.

Further, according to the concrete column earthquake-resistant structure according to claim 5 of the present invention,
By providing the stud bolt on the rear surface of the steel plate, the stud bolt prevents the non-shrinkable mortar from being displaced from the steel plate, and the buckling can be further enhanced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing one embodiment of the present invention.

FIG. 2 is a partially omitted front view showing an embodiment of the present invention.

FIG. 3 is a transverse sectional view showing a modification of the present invention.

FIG. 4 is a cross-sectional view showing an example of the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Concrete strut 14 Steel plate 14a Side edge 15 Anchor bolt 16 Connection plate 17 Nut 18 Stud bolt 21 Non-shrinkable mortar

Continued on the front page (72) Inventor Ken Ken Takano 159-15 Tottoricho, Maebashi, Gunma Prefecture Inside Takano Iron Works, Ltd.

Claims (5)

[Claims] 1. A seismic reinforcement of a concrete strut, wherein a steel plate is arranged surrounding the surface of an existing concrete strut, and the steel plate is fixed via anchor bolts planted on the concrete strut. Construction. 2. The steel plate is divided into a plurality of pieces in the circumferential direction of a concrete pillar, and the steel plates are connected to each other by welding connection plates to side edges of the steel plates. The connection plates are fixed to the anchor bolts. The seismic strengthening structure for a concrete column according to claim 1, wherein the structure comprises: 3. The method according to claim 1, wherein the steel plate is divided into a plurality in the circumferential direction of the concrete column, and the side edges of these steel plates are overlapped with each other, and the overlapped portion is fastened to the anchor bolt together. The seismic reinforcement structure for a concrete column according to claim 1. 4. The method according to claim 1, wherein a gap is provided between the concrete column and the steel plate, and the gap is filled with concrete or mortar. The seismic retrofit structure of the concrete column described in Crab. 5. The structure according to claim 4, wherein a stud bolt is protruded from a back surface of the steel plate.