JPH09273317A - Vibration-resistant reinforcing method of existing concrete structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily, safely, and rapidly reinforce an existing concrete structure in indoor works without use of large construction machines. SOLUTION: Wall-reinforcing core rods 13 vertically extending along a boundary wall 2 side face are arranged, in the mutually facing central parts of the adjacent boundary wall side faces in the inside of a schoolroom 8 and slab- reinforcing core rods 15 are arranged along the underface of the floor slab 14 to be laid between the wall-reinforcing core rods 13. A form 19 is installed and concrete is placed to construct a new column-beam structure 12 for vibration-resistant reinforcement in the girder-direction in the inside of the schoolroom 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for seismic retrofitting an existing concrete structure, in particular, for improving the frame strength of a concrete structure such as a school building in the girder direction.

[0002]

2. Description of the Related Art Concrete structures such as existing school buildings are
Generally, a boundary wall (bearing wall) that is effective as a seismic element is provided in the beam-to-beam direction, but in the girder direction due to lighting, it is a hanging wall without a wall on the entire surface, a beam with a waist wall or a hanging wall,
The structure is composed of beams (wall girders) that also serve as waist walls, and the frame structure in the girder direction could be damaged due to insufficient horizontal bearing capacity due to uncertain external forces such as during a large earthquake.

Therefore, as a method of reinforcing the column-beam structure in the girder direction, a slit is provided at the boundary between the hanging wall and the pillar of the beam with the waist wall and the hanging wall and the waist wall to suppress the stress transmission from the pillar. I am trying.

In addition to this, a brace is integrally attached to the column wall frame on the outer wall surface in the girder direction so as to have a resistance force in the diagonal direction of the frame, thereby improving the rigidity of the column beam frame.

[0005]

However, in any of the conventional methods for reinforcing the seismic resistance of the existing concrete structure as described above, it is possible to reinforce the existing concrete structure without impairing the daylighting function, but a large-scale external temporary installation. There is a drawback that the work is complicated and the construction efficiency is poor because the work is performed at a high place which requires a scaffold and a lifting machine.

Further, in particular, in the method of arranging the brace on the outer wall surface in the column direction, there is a problem that the appearance of the structure is impaired because the outer wall surface and the brace material are out of balance.

[0007] Therefore, the present invention has been made in view of the above-mentioned unsolved problems of the prior art, and can be easily and safely carried out in a short period of time by indoor work without using large-scale construction equipment. The purpose of the present invention is to provide a seismic retrofitting method for existing concrete structures.

[0008]

In order to solve the above-mentioned problems, the method for seismic retrofitting of an existing concrete structure according to the present invention is provided at a predetermined position on opposing wall surfaces inside an existing concrete structure. Wall reinforcement cores extending in the vertical direction along the wall surface are reinforced, and slab reinforcement cores are laid along the bottom surface of the floor slab by straddling between the opposing wall reinforcement cores to strengthen the wall. The feature is that concrete is poured so as to bury the core material and the slab reinforcement core material.

Thus, a new column-beam frame is constructed in the girder direction of the internal space of the structure, and the frame strength in the girder direction is improved without impairing the function of the internal space. Further, the work is indoor work inside the structure, and the rebar is assembled and the form is installed by using only a small jig or winch without using a temporary scaffold, a lifting machine or the like. In addition, concrete is placed by using a hose from a mixer truck installed on the ground to an indoor space where concrete should be placed.

On the other hand, when the wall-reinforcing core material and the slab-reinforcing core material are made of one of reinforcing bars and steel frames, or a combination thereof, the wall-reinforcing core material and the slab-reinforcing core material are embodied. The pillar-beam structure can be made of any of reinforced concrete (RC), steel-framed concrete (SC), and steel-framed reinforced concrete (SRC) structures.

Further, an insert is driven into a predetermined position on the side surface of the boundary wall to be reinforced and the lower surface of the slab, and an anchor bar is attached to this insert to connect the anchor bar to the wall reinforcing core material and the slab reinforcing core material. In this case, the connection structure between the existing concrete surface and the wall and the slab reinforcing core material is realized, and the anchor bolt is fixed to the concrete surface by screwing the anchor bolt inside the insert embedded in the concrete. Wall reinforcement cores are connected to the anchor bolts for reinforcement.

Further, when a mold is installed around the wall reinforcing core material and the slab reinforcing core material, and concrete is poured into the mold through a through hole formed in the floor slab,
The hose of the mixer truck can be installed in the through hole provided in the slab on the upper floor, and concrete can be fed into the formwork without any gaps. Concrete is built.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an embodiment of a seismic retrofitting method for an existing concrete structure according to the present invention will be described with reference to the drawings.

In FIG. 1, 1 is a concrete structure,
Here, it is applied to the building of a general school. Here, the pillar 3 and the beam 4 in the beam direction of the concrete structure 1
A boundary wall 2 is provided as a seismic element on the frame structure consisting of.

On the other hand, the frame wall 2 composed of the columns 3 and the beams 5 in the girder direction is not provided with the boundary wall 2 as a seismic resistant element, and the outer wall portion is a wall having a beam cross section with a down wall and a waist wall (not shown). It is a girder, and a partition wall 6 is installed on the column-beam frame surface in the girder direction inside the concrete structure 1.
And an existing partition 7 is provided.

As a result, the indoor space surrounded by the adjacent boundary wall 2, wall girder and partition wall 6 is used as a classroom 8 here. Also, the partition wall 6
Is not provided in the vicinity of the pillar 3 and is an opening, and this opening is used as an entrance / exit 9 of the classroom 8.

On the other hand, the boundary wall 2 which is continuous with the boundary wall 2 on the side of the classroom 8 in the beam-to-beam direction is not provided on the entire surface of the beam structure, but only on the outer wall side half surface. The space surrounded by the boundary wall 2, the wall girder and the partition 7 is referred to as a shared room 10 such as a toilet, a washroom, and a changing room here.
The opening of the partition 7 near the pillar is used as the entrance / exit 9.

Further, a space continuous in the column direction on the side where the boundary wall 2 is not provided is used as the corridor 11 here. Concrete structure 1 constructed in this way
In this case, as shown in FIG. 2, it extends vertically along the side faces of the adjacent wall 2 inside the classroom 8 as shown in FIG. The wall reinforcing core material 13 is arranged.

Further, a slab reinforcing core material 15 made of a reinforcing bar is arranged along the lower surface of the floor slab 14 by bridging between the wall reinforcing core materials 13, a formwork 19 is installed, and concrete is poured. Thus, a new column-beam frame structure 12 for seismic reinforcement is constructed in the girder direction inside the classroom 8.

Explaining the concrete seismic strengthening method,
As shown in FIGS. 3 and 4, first, an insert 2 provided with screw portions 20a at predetermined intervals on the side surfaces of the opposing field wall 2 to be reinforced and the lower surface of the floor slab 14 continuous with this field wall 2.
Type 0.

This is easily installed by, for example, drilling the concrete with an electric drill or the like and then driving the insert 20 into the drilled hole. Next, the side wall 2 and the floor slab 1 to be reinforced by screwing the anchor bar 21 into the buried insert 20.
4 Fix this on the bottom surface.

Of the anchor reinforcements 21, the anchor reinforcements 21 for the wall columns installed on the side surfaces of the boundary wall 2 have a bent end, while the anchor reinforcements 21 for the floor beams installed on the lower surface of the floor slab 14 are. Is straight and has screw portions 21a at both ends thereof.

As shown in FIG. 4, a plurality of lateral wall reinforcements 13a are installed by connecting the anchor reinforcements 21 on the side surface of the boundary wall 2 so as to connect them laterally. Further, the wall reinforcing vertical bars 13a are connected by vertically connecting the wall reinforcing horizontal bars 13a.
b is installed.

Further, as shown in FIG. 2, the lower end of the wall reinforcing vertical bar 13b is anchor bar 2 protruding from the floor slab 14.
It is connected to 1. After arranging the wall reinforcing core material 13 in this manner, the formwork 19 is installed at predetermined intervals so as to surround the wall reinforcing core material 13.

On the other hand, as shown in FIG.
Reinforcement core material receiver made of a plate-like member for bridging the anchor bars 21 juxtaposed at a predetermined interval in the width direction among the anchor bars 21 projecting at a predetermined interval so as to bridge The material 22 is inserted through the anchor muscles 21 and fixed by the nut 23.

The slab reinforcing main bars 2 extending in the girder direction so as to be placed on the reinforcing core receiving members 22.
4 are arranged in parallel at a predetermined interval. Further, the slab reinforcing force distribution bars 15b whose both ends are bent upward in a U shape are arranged below the slab reinforcing main bars 15a in parallel with the spaces between the reinforcing core receiving members 22.

Then, the threaded portion 21a formed on the anchor bar 21 projecting to the lower side of the reinforcing core material 15 for the slab penetrates the slab mold frame 19 and the anchor bar 21 protruding from this mold frame 19 is nut. It fixes with 25 and makes the anchor bar 21 function as a separator, and the form 19 for slabs is installed so that both sides and the lower side of the reinforcing core material 15 for slabs may be enclosed.

Further, as shown in FIG. 2, the wall reinforcing core material 13
The joint portion of the slab reinforcement core material 15 is provided with joint reinforcing bars 26 in an oblique direction so as to form a capital portion for strengthening the horizontal strength of a normal column.
A formwork 19 is installed in parallel with 6.

In the same manner as described above, the wall reinforcing core material 13 and the slab reinforcing core material 15 are installed between the boundary walls 2 continuous in the girder row direction, and if necessary, the wall reinforcing core material 1 in the girder row direction of the other floor.
3 and the slab reinforcement core 15 are installed to complete all seismic reinforcement reinforcement, and then concrete is placed in the formwork 19. Here, the slab reinforcement core 15 is installed. A concrete pouring through hole 27 is formed at a predetermined interval in the floor slab 14 at the position where the concrete is placed by connecting a hose connected from a mixer truck installed on the ground to the pouring through hole 27. To place.

Therefore, the concrete poured into the formwork 19 is properly filled into the formwork 19 for the slab, and also passes through the capital portions on both sides to be filled into the formwork 19 for the wall.

In addition to the above-described method, concrete can be poured into the wall formwork by forming a hole at the upper end of the wall formwork 19 and filling concrete appropriately. Further, in the above-described embodiment, the wall reinforcing steel bars 13 and the slab reinforcing steel bars 15 are not necessarily arranged on-site, and only the installation work to the reinforcing place is performed by using the pre-assembled unit steel bars. Is also possible.

Further, the installed formwork 19 is not limited to the formwork for removing the formwork which is removed after the concrete is hardened, and a formwork for driving may be used. Further, in the above-mentioned embodiment, the reinforcing bars are applied to the wall reinforcing core material 13 and the slab reinforcing core material 15, but other than this, it is also possible to use steel frame materials made of any shape steel. Further, it may be a composite structure of reinforcing bars and steel frames.

When the cast concrete is hardened, a seismic frame composed of new studs and girders is constructed inside the concrete structure 1 in the direction of the girders. Therefore, a frame structure having a flat cross section that is continuous along the side surface and the upper surface in the classroom 8 is constructed, and seismic reinforcement can be performed without impairing the daylighting function and the like inside the classroom 8. By transmitting the shearing force to each layer, the frame rigidity in the girder direction can be significantly improved.

Further, a capital portion is formed at the joint portion of the constructed studs and studs, whereby the shear strength of the joint portion can be significantly improved. On the other hand, in this seismic reinforcement method, all the work such as installation of anchor bars 21, assembly of wall reinforcing bars 13 and slab reinforcing bars 15 and installation of formwork is performed indoors, and a large-scale hoisting machine or the like is used. It is carried out easily and safely by a small jig or winch without using it.

In the above embodiment, the case of constructing a frame structure composed of a wall pillar and a floor beam having a flat cross section between existing column beam frames in the girder direction has been described, but the shape is not necessarily limited to this. Instead, for example, as shown in FIG. 5, a plurality of seismic reinforcement columns 3 are provided between the columns in the inter-beam direction in the classroom 8 and the field walls 2 facing each other in the girder direction are connected by the beam 28. You can also Further, as shown in FIG. 6, the existing beam 28 is arranged in the girder direction of the concrete structure 1.
, The boundary wall 2 that intersects with the beam 28.
It is also possible to newly construct only the column 3 for seismic reinforcement that extends in the vertical direction of the plane.

Further, as shown in FIG. 7, a wall-reinforcing pillar 3 having a flat cross section is constructed on the field wall 2 surface that straddles between the existing beam beams 28, and It is also possible to form a new earthquake-resistant frame composed of pillars 3 of.

Further, in the above embodiment, the concrete structure 1 was described as a case of reinforcing the column beam structure in the girder direction in the existing school building which is not provided with the seismic wall in the girder direction, but the invention is not necessarily limited to this. Needless to say, the present invention can be applied to the case of reinforcing a column-frame structure having insufficient seismic strength of any concrete structure 1.

[0038]

As described above, the seismic retrofitting method for an existing structure of the present invention is provided in a vertical direction along the side wall side face at a predetermined position on the side wall adjacent to each other inside the existing concrete structure. By arranging the extending wall reinforcement cores, spanning between the wall reinforcement cores and arranging the slab reinforcement cores along the bottom surface of the floor slab and placing concrete, A new column-beam structure is constructed that is continuous along the side and top surfaces. Therefore, it is possible to perform seismic reinforcement without unnecessarily impairing the interior lighting function and the like, and to transmit the shearing force generated between the upper and lower layers to significantly improve the frame rigidity in the girder direction.

Further, all the work such as installation of anchor bars, assembly of reinforcing bars and installation of formwork is carried out indoors, and a small jig or winch can be used to easily and easily without using a large-scale lifting machine. It is carried out safely. In addition, at the time of pouring concrete, a hose connected from a mixer truck installed on the ground can be installed in a formwork to be reinforced in a room to easily perform the work.

[Brief description of drawings]

FIG. 1 is a plan view showing an existing concrete structure applied to an earthquake-proof reinforcing method for an existing concrete structure according to an embodiment of the present invention.

2 is a side view showing seismic reinforcement of the existing concrete structure of FIG. 1. FIG.

3 is an enlarged view of a portion A in FIG. 2, where FIG. 3 (a) is a side sectional view and FIG. 3 (b) is a sectional view taken along line BB in FIG. 3 (a).

FIG. 4 is a cross-sectional view taken along the line CC of FIG.

FIG. 5 is a plan view showing a modified example of the seismic retrofitting method for an existing concrete structure according to the embodiment of the present invention.

FIG. 6 is a plan view showing a modified example of the seismic retrofitting method for an existing concrete structure according to the embodiment of the present invention.

FIG. 7 is a plan view showing a modified example of the seismic retrofitting method for an existing concrete structure according to the embodiment of the present invention.

[Explanation of symbols]

 1 ... Concrete structure 2 ... Boundary wall 3 ... Pillar 4 ... Beam 5 ... Beam 6 ... Partition wall 7 ... Partition 8 ... Classroom 9 ... Entrance / exit 10 ... Shared room 11 ... Corridor 12 …… Column beam structure 13 …… Wall reinforcement core 14 …… Floor slab 15 …… Slab reinforcement core 16 …… Corridor 19 …… Form 20 …… Insert 21 …… Anchor reinforcement

Claims (4)

[Claims] 1. A wall reinforcing core material extending vertically along the boundary wall surface is provided at a predetermined position of the opposing wall surface inside the existing concrete structure, and the wall reinforcing core material is provided between the opposing wall wall materials. A method for earthquake-proofing reinforcement of an existing concrete structure, characterized in that a slab reinforcing core material is provided along a lower surface of a floor slab, and concrete is poured so as to bury the wall reinforcing core material and the slab reinforcing core material. 2. The method for earthquake-proofing reinforcement of an existing concrete structure according to claim 1, wherein the wall reinforcing core material and the slab reinforcing core material are made of either reinforcing bars or steel frames, or a combination thereof. Seismic strengthening method for existing concrete structures. 3. The method for seismic retrofitting an existing concrete structure according to claim 1, wherein an insert is driven into predetermined positions on a side wall of a boundary wall and a lower surface of a slab to be reinforced, and an anchor bar is attached to the insert. A seismic retrofitting method for an existing concrete structure, characterized in that a streak is connected to the wall reinforcing core material and the slab reinforcing core material. 4. The method for seismic retrofitting an existing concrete structure according to claim 1, wherein a formwork is installed around the wall reinforcing core material and the slab reinforcing core material, and the through hole is formed in the floor slab. A method for seismic retrofitting an existing concrete structure, characterized by placing concrete in a formwork.