JPH09177334A - Reinforcing method for existing post - Google Patents

Abstract

PROBLEM TO BE SOLVED: To contrive to enhance shearing strength of an existing post by surrounding the periphery of an existing post in such a fashion that the end of a reinforcing steel plate may be placed one upon the other and fixing the steel plate with the post with a bolt from manipulating from the outside of the folded area and filling up shrinkage compensating mortar between the reinforcing steel plate and the existing post. SOLUTION: A reinforcing plate 2 is molded in a specified shape so as to comply with an existing post 1, at first. Then, the surrounding area of the existing post 1 is surrounded with the reinforcing steel 2 so that the end 2a of the reinforcing steel plate 2 may be placed one upon the other respectively. Then, they are fixed with a bolt from the outside of the folding area 2a of the reinforcing steel plate 2. Finally, shrinkage compensating mortar is filled up in a clearance between the reinforcing steel plate 2 and the existing post 1, thereby curing the mortar and fixing the steel plate 2 with the existing post 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for reinforcing existing columns.

[0002]

2. Description of the Related Art As is well known, in building structures,
By aging or for the purpose of improving earthquake resistance,
There is often a demand for reinforcement of existing building structures without rebuilding.

In this case, for existing columns, generally,
It is effective to either place a reinforced concrete with a specified thickness around the existing columns, or wind a reinforcing steel plate around the existing columns and weld the joints to cover the existing columns with the sheath of the reinforcing steel plate. And it is said to be convenient.

[0004]

However, in the method of reinforcing existing columns, the method of placing reinforced concrete around the existing columns not only requires a large number of man-hours and time for reinforcement and curing, but also requires a new method. The reinforcing effect cannot be obtained unless the thickness of the reinforced concrete layer to be cast is considerably increased, so that the cross section of the column after reinforcement increases and the utilization efficiency of the floor surface decreases.

Further, the method of covering the existing column with the sheath of the reinforcing steel plate requires welding the joint portion of the reinforcing steel plate on site, and requires a high degree of skill to ensure a predetermined quality. become. It also requires a lot of time and effort.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method of reinforcing an existing column which is easy to construct. Further, it is possible to prevent the utilization efficiency of the floor surface from decreasing as much as possible. The purpose is to provide a method of reinforcing existing columns.

[0007]

A method for reinforcing an existing column according to claim 1 is a method for reinforcing an existing column, the method comprising:
Around the existing pillar, while enclosing the end portions of the reinforcing steel plate by a reinforcing steel plate in a state of being overlapped with each other,
The superposed portion of the reinforcing steel plate is fixed by bolts only from the outside of the superposed portion, and non-shrink mortar is filled between the reinforcing steel plate and the existing column. The method for reinforcing an existing column according to claim 2, wherein in the method for reinforcing an existing column according to claim 1, the bolt has a bolt main body having a locking portion on one end side, and the other end side of the bolt main body. A nut screwed to the pressing member, a pressing member located between the nut and the locking portion and capped on the outside of the bolt main body, and a pressing member positioned between the pressing member and the locking portion. The outer diameter of the bolt main body, the diameter of which is expanded by being crushed between the pressing member and the locking portion when the nut is rotated and moved toward the locking portion. And a member. In the method for reinforcing an existing column according to claim 3, in the method for reinforcing an existing column according to claim 1 or 2, a portion of the bolt that corresponds to the bolt of the existing column,
It is characterized in that a recess for accommodating a portion protruding from the reinforcing steel plate toward the inside of the existing column is formed.

According to the first aspect of the present invention, the periphery of the existing column is surrounded by the reinforcing steel plate fixed by the non-shrink mortar, so that the shear strength of the existing column is improved. In this case, since the overlapping portion of the reinforcing steel plates is fixed with the bolts by the operation from only the outside of the overlapping portion, the reinforcing steel plates can be easily fixed. According to the invention described in claim 2,
When the nut is rotated and moved toward the locking portion of the bolt body, the diameter expanding member is crushed and expanded between the pressing member and the locking portion to expand the diameter. This enlarged diameter portion functions as a locking portion, and can be fixed by operation from only one side. According to the invention described in claim 3, of the bolt,
The part protruding from the reinforcing steel plate toward the inside of the existing pillar is
Since it is housed in the recess of the existing pillar, the reinforcing steel plate is arranged as close as possible to the existing pillar.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a method for reinforcing an existing column of the present invention will be described below with reference to the drawings.

[First Embodiment] FIG. 1 shows a first embodiment of a reinforcing structure for an existing column according to the present invention. In the figure, reference numeral 1 is an existing column, 2 is a reinforcing steel plate, 3 is a bolt, and 4 is a bolt. Indicates a recess.

The existing column 1 is, for example, a column made of reinforced concrete extending in a square cross section, and is a subject to be reinforced in the present invention.

The reinforcing steel plate 2 is a steel plate formed into a shape capable of surrounding the existing column 1. In the example shown in FIG.
One L-shaped steel plate is used. These reinforcing steel plates 2
Is arranged so as to surround the periphery of the existing column 1 in a state where the adjacent reinforcing steel plates 2 are overlapped with each other at their end portions 2a to form the overlapping portion 10. Further, the reinforcing steel plate 2 is formed with a bolt insertion hole (not shown) for a bolt 3 described later.

The bolt 3 is a high tensile bolt which can be installed from only one direction. The structure of the bolt 3 will be described with reference to FIG. In the figure, reference numeral 20 is a bolt body,
30 is a nut and 40 is a diameter expansion member.

The bolt main body 20 is composed of a head portion (locking portion) 21 located on one end side and a shaft portion 22. Shaft portion 22 located on the other end side of the bolt body 20
The front end of is a male screw portion 22a.

The nut 30 has a female screw hole 31 which is screwed into the male screw portion 22a, and the female screw hole 31 is formed in the male screw portion 2.
By being screwed to 2a, it is screwed to the tip of the bolt body 20. Between the nut 30 and the reinforcing steel plate 2,
A bearing washer 32 for smoothing the rotation of the nut 30 is provided.

A space between the head 21 of the bolt body 20 and the nut 30 is covered on the outside of the shaft portion 22 of the bolt body 20, and the diameter expanding member 40 and the sleeve (pressing member) are arranged in this order from the head 21 side. 41 and a washer 42 are interposed. At this time, the diametrical expansion member 40 is made of a material having a property of being more easily crushed and compressed than the sleeve 41 and the washer 42.

In the bolt 3 having the above structure, when the nut 30 is rotated, the diameter expanding member 40 is crushed between the sleeve 41 and the head 21 to expand the diameter as shown in FIG. 2 (b). The part 40a is formed. further,
When the nut 30 is rotated, as shown in FIG.
The shaft portion 22 is pulled toward the nut 30, and the expanded diameter portion 40a
Are locked to the reinforcing steel plate 2. By utilizing the locking function of the expanded diameter portion 40a, the nut 30 is rotated to a predetermined position as shown in FIG. As described above, the fixing operation can be performed only from one side.

In place of the bolt 3, a nut 45 may be welded to the reinforcing steel plate 2 in advance, as shown in FIG. Also in this case, the reinforcing steel plates 2 can be fixed to each other using the high-tensile bolts 46 by operating only from the outside.

Now, returning to the description of FIG. 1, the recess 4 is formed in the portion of the existing pillar 1 corresponding to the installation location of the bolt 3, and when the bolt 3 is installed, the bolt 3 This is for accommodating a portion protruding from the reinforcing steel plate 2 toward the inside of the existing column 2.

Next, a method of constructing the reinforcing structure will be described. First, the reinforcing steel plate 2 is formed into a predetermined shape according to the existing pillar 1. Then, the periphery of the existing pillar 1 is surrounded by the reinforcing steel plate 2 in a state where the end portions 2 a of the reinforcing steel plate 2 are overlapped with each other.

Further, the overlapping portion 10 of the reinforcing steel plate 2 is fixed with the bolt 3 only from the outside of the overlapping portion 10.
Finally, the gap 11 between the reinforcing steel plate 2 and the existing pillar 1 is filled with non-shrink mortar and solidified, and the reinforcing steel plate 2 is fixed to the existing pillar 1.

In the method of reinforcing the existing pillars 10, the existing pillars 1 are
Can be surrounded by the reinforcing steel plate 2 fixed by non-shrink mortar, and the shear strength of the existing column 1 can be improved to effectively carry out the reinforcement. In this case, since the overlapping portion 10 of the reinforcing steel plate 2 is fixed with the bolt 3 by an operation from only the outside of the overlapping portion 10, the reinforcing steel plate 2 can be easily fixed, and the construction is easily achieved. be able to.

According to the bolt 3, the nut 30
By rotating the diametrically expanded member 40, the diametrically expanded member 40 is crushed and expanded in diameter, and this expanded diameter expanded portion 40a can function as a locking portion, and the reinforcing steel plates 2 are fixed to each other by an operation from only one side. Can be achieved.

Further, the portion of the bolt 3 projecting from the reinforcing steel plate 2 toward the inside of the existing pillar 1 is formed in the recess 4 of the existing pillar 1.
Since it is housed inside, the reinforcing steel plate 2 can be arranged as close as possible to the existing pillar 1, the increase in the cross-sectional area of the pillar due to the reinforcement can be suppressed as much as possible, and the use efficiency of the floor surface can be reduced. It can be prevented as much as possible.

Moreover, since only small bolt insertion holes are formed in the reinforcing steel plate 2, the strength of the reinforcing steel plate 2 can be fully utilized without lowering the strength of the reinforcing steel plate 2.

[Second Embodiment] FIG. 4 shows a second embodiment of the reinforcing structure for an existing column according to the present invention. In this embodiment, the same components as those in the first embodiment are designated by the same reference numerals, and the description thereof will be appropriately omitted.

The reinforcing steel plate 2 is formed in a round shape instead of the L-shaped section. And the existing beam 5 connected to the existing pillar 1
A notch 2b is formed in a portion corresponding to 0, and a flange portion 2c having a shape along the side surface 50a of the existing beam 50 is formed. And the opposing flange portion 2
c is a through bolt 51 through which the existing beam 50 is inserted.
Are connected by

In this embodiment, the construction can be performed in the same manner as the first embodiment, and similarly, the existing pillar 1 can be effectively and easily reinforced with the reinforcing steel plate 2.

In addition, not only can the portion of the existing column 1 that is connected to the existing beam 50 be reinforced, but the flange portion 2c can also be used for the beam 5.
By supporting 0 as an auxiliary, the existing beam 50 can be reinforced at the same time.

[Third Embodiment] FIG. 5 shows a third embodiment of the method for reinforcing an existing column of the present invention. The present embodiment is different from the first embodiment only in the configuration of the overlapping portion 10, and is the same in the other configurations.

As shown in FIG. 5, the reinforcing steel plate 2 is doubled by bending at the portion corresponding to the overlapping portion 10, and fillet welded at the end portion 2a. The bending operation and welding at this time are performed in advance in the factory. The reinforcing steel plates 2 and 2 are fastened with the bolts 3 in the above state.

In the present embodiment, the same functions and effects as those of the first embodiment can be obtained. In addition, since the reinforcing steel plates 2 and 2 are double in the overlapping portion 10, the strength of the fastening portion can be improved.

[Fourth Embodiment] FIG. 6 shows a fourth embodiment of the method for reinforcing an existing column of the present invention. The present embodiment is different from the first embodiment only in the configuration of the overlapping portion 10, and is the same in the other configurations.

As shown in FIG. 6, each reinforcing steel plate 2 is
In the portion corresponding to the overlapping portion 10, the reinforcing plate 60 is doubled by being fillet-welded at the edge 60a. The welding at this time is performed in advance in the factory. The reinforcing steel plates 2 and 2 are fastened with the bolts 3 in the above state.

In this embodiment, the same operational effects as those of the first embodiment can be obtained. In addition, in the overlapping portion 10, since the reinforcing steel plates 2 and 2 are reinforced by the reinforcing plates 60 and 60, respectively, the strength of the fastening portion can be improved.

[Fifth Embodiment] FIG. 7 shows a fifth embodiment of the reinforcing method for an existing column of the present invention. The present embodiment is different from the first embodiment only in the configuration of the overlapping portion 10, and is the same in the other configurations.

As shown in FIG. 7, a reinforcing plate 65 is welded to the end portion 2a of one reinforcing steel plate 2. The welding at this time is performed in advance in the factory. The other reinforcing steel plate 2 and the reinforcing plate 65 are fastened together by the bolts 3.

In this embodiment, the same operational effects as those of the first embodiment can be obtained. In addition, FIG.
As shown in, the outer surfaces of the reinforcing steel plates 2 and 2 can be installed flush with each other.

[Sixth Embodiment] FIG. 8 shows a sixth embodiment of the reinforcing method for an existing column of the present invention. The present embodiment differs from the fifth embodiment only in the structure of the overlapping portion 10, and is the same in the other parts.

As shown in FIG. 8, the reinforcing plate 65 is welded as in the fifth embodiment. In addition, a reinforcing plate 66 is attached when fastening the bolt 3. Further, the bolts 3, 3 are fastened separately in the width direction of the overlapping portion 10.

In this embodiment, the same operational effects as those of the first embodiment can be obtained. In addition, since the reinforcing steel plates 2 and 2 are reinforced by the reinforcing plates 65 and 66 in the overlapping portion 10, the strength of the fastening portion can be improved.

The present invention is not limited to the above-described embodiment, and the following modifications do not depart from the gist of the present invention. a) Instead of applying to the existing columns 1 made of reinforced concrete, it is applied to existing columns made of any material such as existing columns made of steel reinforced concrete. b) Instead of being applied to the existing pillar 1 having a square pillar shape with a quadrangular cross section, the present invention is applied to an existing pillar having a prism shape having another cross sectional shape such as a pentagonal cross section or a hexagonal cross section. Alternatively, apply to existing columns with arbitrary cross-sectional shapes, such as circular cross-sections and elliptical cross-sections. c) In the first embodiment, four L-shaped reinforcing steel plates 2
Instead of surrounding the existing beam 1, the surrounding beam 1 is surrounded by a reinforcing steel plate having an arbitrary shape and an arbitrary number (may be one or plural). In any case, the structure in which the end portions are overlapped with each other is as described in the embodiment section. d) In the first embodiment, the connecting portion with the beam has the same configuration as in the second embodiment. e) In the second embodiment, a recess corresponding to the recess 4 in the first embodiment is formed, and the reinforcing steel plate 2 is arranged along the shape of the existing pillar 1.

[0043]

According to the method of reinforcing an existing column of the present invention, the following effects can be obtained. According to the method of reinforcing an existing column according to claim 1, the periphery of the existing column can be surrounded by a reinforcing steel plate fixed by non-shrink mortar, and the shear strength of the existing column is improved to effectively reinforce the existing column. be able to. In this case, since the overlapping portion of the reinforcing steel plate is fixed by the bolt only by operating from the outside of the overlapping portion, the reinforcing steel plate can be easily fixed and the construction can be easily achieved. According to the method of reinforcing an existing pillar according to claim 2, the nut is rotated to move toward the locking portion of the bolt body, thereby crushing and expanding the diameter expanding member,
This expanded diameter portion can be made to function as a locking portion, and fixing by operation from only one side can be achieved. According to the method of reinforcing an existing column according to claim 3, since the portion of the bolt that protrudes from the reinforcing steel plate toward the inside of the existing column is housed in the recess of the existing column, the reinforcing steel plate is used as the existing column. You can place them as close to each other as possible,
It is possible to suppress the increase in column cross-sectional area due to reinforcement as much as possible,
It is possible to prevent a decrease in utilization efficiency of the floor surface as much as possible.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of a reinforcing structure for an existing column according to the present invention.

FIG. 2 is a cross-sectional view showing a bolt used in FIG. 1, and FIGS. 2 (a) to (d) sequentially show a fastening process.

FIG. 3 is a cross-sectional view showing a configuration example in which a bolt can be substituted.

FIG. 4 is a perspective view showing a second embodiment of the existing pillar reinforcing structure according to the present invention.

FIG. 5 is a cross-sectional view showing a part of a third embodiment of an existing column reinforcing structure according to the present invention.

FIG. 6 is a cross-sectional view showing a part of a fourth embodiment of an existing column reinforcing structure according to the present invention.

FIG. 7 is a cross-sectional view showing a part of a fifth embodiment of an existing column reinforcing structure according to the present invention.

FIG. 8 is a cross-sectional view showing a part of a sixth embodiment of an existing column reinforcing structure according to the present invention.

[Explanation of symbols]

 1 Existing column 2 Reinforcement steel plate 2a End part 3 Bolt 4 Recess 10 Lap part 20 Bolt body 21 Head (locking part) 30 Nut 40 Expanding member 41 Sleeve (pressing member)

Claims (3)

[Claims] 1. A method of reinforcing an existing column, comprising enclosing the periphery of the existing column with a reinforcing steel plate in a state in which end portions of the reinforcing steel plate are overlapped with each other,
An existing column characterized in that the superposed portion of the reinforcing steel plate is fixed by a bolt by an operation only from the outside of the superposed portion, and further non-shrink mortar is filled between the reinforcing steel plate and the existing column. Reinforcement method. 2. The method for reinforcing an existing pillar according to claim 1, wherein the bolt has a bolt body having a locking portion on one end side, and a nut screwed to the other end side of the bolt body. A pressing member located between the nut and the locking portion and covered on the outside of the bolt main body, and an outside of the bolt main body located between the pressing member and the locking portion. And a diameter-expanding member that expands the diameter by being crushed between the pressing member and the locking portion when the nut is rotated and moved toward the locking portion. A method of reinforcing existing columns, which is characterized by 3. The method of reinforcing an existing column according to claim 1, wherein a portion of the existing column corresponding to the bolt protrudes from the reinforcing steel plate of the bolt toward the inside of the existing column. A method for reinforcing an existing column, characterized by forming a recess for accommodating a part.