JP6261333B2 - Seismic reinforcement method - Google Patents

Description

  The present invention relates to a seismic reinforcement method for reinforcing an existing frame with an additional beam made of concrete with respect to an existing beam and a reinforcing frame integrally provided below the additional beam.

  Patent Document 1 discloses a seismic reinforcement method for reinforcing an existing frame by forming a reinforcing beam made of concrete with respect to an existing beam and then integrally connecting a reinforcing frame below the additional beam.

In other words, reinforcing bars are arranged on the outer surface side of the existing beam surrounding the upper part of the opening, and the formwork that surrounds these reinforcing bars is placed and concrete is placed to form an additional beam that surrounds the upper part of the opening. To do.
After that, the reinforcement frame is attached to the opening side below the reinforcement beam, a mold frame surrounding the reinforcement beam and the reinforcement frame is installed, and the mortar is filled inside the mold frame to increase the reinforcement beam. A reinforcement frame is integrally provided below the bottom.

JP 2011-214261 A

In the above conventional seismic reinforcement method, after the reinforcement beam is formed, the reinforcement frame is attached below the reinforcement beam. Therefore, the reinforcement frame is attached until the curing period of the concrete forming the reinforcement beam elapses. It cannot be started, and it is difficult to shorten the construction period.
Moreover, in order to support the formwork surrounding the reinforcing bars for the additional beam with the concrete placed inside, it is necessary to separately install a supporting work such as a support column.
For this reason, it takes time to install and remove the support work, and it is difficult to improve the work efficiency.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a seismic reinforcement method that facilitates shortening the work period and improving work efficiency.

The characteristic configuration of the seismic retrofit method according to the present invention is a seismic retrofit method that reinforces an existing frame with a concrete additional beam for an existing beam and a reinforcement frame integrally connected below the additional beam. The reinforcing frame has a rectangular portion provided on the left and right existing pillars, and the reinforcing frame is installed at a predetermined position prior to the formation of the additional beam. The reinforcement beam is formed in a state adjacent to the upper side of the rectangular portion as a support work.

In the seismic reinforcement method of this configuration, the reinforcement frame is installed at a predetermined position prior to the formation of the additional beam, and the additional beam is formed by using the previously installed reinforcement frame as a support.
For this reason, the attachment operation | work of a reinforcement frame can be started, without waiting for progress of the curing period of the concrete which forms an additional beam.
Further, it is possible to form an additional beam without separately installing a support work such as a support, that is, without taking time and effort to install and remove the support work.
Therefore, with the seismic reinforcement method of this configuration, it is easy to shorten the work period and improve the work efficiency.

  Another feature of the present invention is that the reinforcing frame is installed for each of a plurality of vertically adjacent frames in the state where a position holding member capable of transmitting the vertical load is interposed. A plurality of additional beams are formed with respect to the existing beams of each frame using the holding member as a support.

In this configuration, the reinforcing frame for each of the plurality of frames adjacent to each other in the vertical direction is installed so that the load acting on the reinforcing frames is transmitted vertically through the position holding member.
For this reason, it is possible to simultaneously form a plurality of additional beams corresponding to the existing beams of each frame by using these reinforcing frames and position holding members as support works, and it is easier to shorten the work period and improve the work efficiency. .

It is the front view which looked at the building outer wall before reinforcement from the building outer side. It is sectional drawing which shows the building outer wall before reinforcement. It is the front view which looked at the building outer wall after reinforcement from the building outer side. It is sectional drawing which shows the building outer wall after reinforcement. It is the front view seen from the building outer side explaining the seismic reinforcement method. It is sectional drawing which shows the building outer wall explaining the earthquake-proof reinforcement method. It is an expanded sectional view explaining an earthquake-proof reinforcement method.

Embodiments of the present invention will be described below with reference to the drawings.
1 and 2 show an existing reinforced concrete building outer wall A before reinforcement.
3 and 4 show the building outer wall B after reinforcement reinforced by the seismic reinforcement method according to the present invention.

The building outer wall A before reinforcement will be described.
As shown in FIGS. 1 and 2, the building outer wall A before reinforcement is spaced between the existing pillar 1 constructed at a distance from side to side and above the lower existing structure 2 and the lower existing structure 2. A plurality of existing upper frames 3 adjacent in the vertical direction are integrally constructed.

The lower existing frame 2 integrally includes a lower floor slab 2a, a lower existing beam 2b that supports the outer periphery of the lower floor slab 2a, and a foundation concrete portion 2c.
Each of the upper existing frames 3 integrally includes an upper floor slab 3a and an upper existing beam 3b that supports the outer periphery of the upper floor slab 3a.

The existing column 1 is provided in a cross-sectional shape that protrudes toward the outside of the building from the outer surfaces of the lower existing beam 2b and the upper existing beams 3b.
An existing window space 4 is opened between the lower existing beam 2b and the upper existing beam 3b and between the upper existing beams 3b adjacent in the vertical direction.

The building outer wall B after reinforcement will be described.
As shown in FIGS. 3 and 4, the building outer wall B after reinforcement is reinforced by reinforcing the lower existing frame 2 with a lower concrete beam 5 made of concrete with respect to the lower existing beam 2b, and each of the upper existing frames 3 as upper existing beams. The upper reinforcing beam 6 made of concrete with respect to 3b and the reinforcing frame 7 integrally provided below the upper additional beam 6 are reinforced.
The lower additional beam 5 and each upper additional beam 6 are integrally provided on the outer side of the lower existing beam 2b or the upper existing beam 3b across the existing pillars 1 on the left and right.

The reinforcing frame 7 is installed in a portion surrounded by a rectangle between the additional beams 5 and 6 adjacent to each other in the vertical direction and the existing pillars 1 on the left and right sides, a rectangular frame frame (an example of a rectangular portion) 7a, and a frame frame A pair of brace frames 7b arranged and fixed in a V shape on the inner peripheral side of 7a.
The frame frame 7a and the brace frame 7b are made of an H-shaped steel in which a web plate is arranged in a vertical orientation.

A method for reinforcing the lower existing frame 2 and the upper existing frame 3 and constructing the reinforced building outer wall B will be described with reference to FIGS.
Note that the existing upper frame 3 is reinforced with an upper additional beam 6 and a reinforcing frame 7 constructed by using the seismic reinforcement method according to the present invention.

Before the upper existing frame 3 is reinforced, the lower existing beam 2 is reinforced by forming a lower additional beam 5 on the outside of the building of the lower existing beam 2b.
Then, in order to reinforce the upper existing frame 3, the reinforcing frame 7 is installed at a predetermined position prior to the formation of the upper increased beam 6.
Between each reinforcing frame 7, the lower additional beam 5 and the existing pillar 1, spiral bars 10a and anchor bars 10b are arranged.

  The reinforcing frame 7 is a state in which a frame frame 7a and a pair of brace frames 7b are integrally attached in advance, and a bundle member (an example of a position holding member) 9a, 9b such as a shape steel capable of transmitting a vertical load is interposed. Install in.

The reinforcing frame 7 for the lowermost existing upper frame 3 is supported in a positioned state on a bundle member 9 b installed on the upper surface of the lower additional beam 5.
The reinforcement frames 7 for the remaining upper existing frame 3 are supported in a positioned state on a bundle member 9a interposed between the reinforcement frames 7 installed on the lower side.

  Next, a reinforcing bar 8a, an anchor bar 8c, and the like are arranged at a place where the upper extra beam 6 is to be formed and surrounded by the mold 8.

As shown in FIG. 7, the mold 8 to be installed at a place where the upper additional beam 6 is to be formed is detachably supported and installed with respect to the reinforcing frame 7.
In addition, since the formwork 8 is installed so that the bundle member 9a installed between the upper and lower reinforcement frames 7 may be enclosed, these bundle members 9a are embed | buried under the concrete part of the upper reinforcement beam 6. FIG.

  Next, concrete is cast inside the mold 8, and the upper reinforcement beam 7 and the bundle members 9a and 9b installed in advance are supported to support the upper existing beams 3b of the upper existing frames 3 in a plurality of upper repeated shots. The beam 6 is formed simultaneously.

And the formwork 8 is removed after progress of a predetermined curing period, and as shown in FIG. 1 and FIG. 2, each upper existing frame 3 is seismically reinforced with an additional beam 6 and a reinforcing frame 7. The outer wall B is constructed.
Further, a grout is placed between each reinforcing frame 7 and the lower additional beam 5 and the existing pillar 1 to complete the seismic reinforcement.

[Other Embodiments]
1. In the seismic strengthening method according to the present invention, the additional beam that corresponds to each of a plurality of existing frames that are adjacent in the vertical direction may be constructed for each existing frame in order from the beam that is installed below.
2. The seismic reinforcement method according to the present invention can be carried out by appropriately selecting the type, shape, arrangement, quantity, and the like of the reinforcing bars to be used and the specific structure of the reinforced beam and the reinforcing frame.

1 Existing column 3 (Upper) Existing frame 3b (Upper) Existing beam 6 (Upper) Reinforced beam 7 Reinforcement frame
7a Frame frame (rectangular part)
9a, 9b Position holding member

Claims (2)

A seismic reinforcement method for reinforcing an existing frame with an additional concrete beam for an existing beam and a reinforcing frame integrally connected below the additional beam,
The reinforcing frame has a rectangular portion provided over the existing pillars on the left and right,
Prior to the formation of the additional beam, the reinforcing frame is installed at a predetermined position,
A seismic reinforcement method for forming the additional beam in a state adjacent to the upper side of the rectangular portion by using the reinforcing frame installed in advance as a support. In a state where a position holding member capable of transmitting the vertical load is interposed, the reinforcing frame for each of a plurality of frames adjacent vertically is installed,
The seismic reinforcement method according to claim 1, wherein the plurality of additional beams for the existing beams of each frame are formed by supporting the previously installed reinforcing frame and the position holding member.

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