JP2009257039A - Aseismatic reinforcing method and aseismatic reinforcing structure for existing building - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aseismatic reinforcing method and an aseismatic reinforcing structure for an existing building that can fully exhibit a required reinforcing effect with excellent workability and economical efficiency without needing large-scale construction besides making effective use of an existing frame in spite of an aseismatic reinforcing technology of the type of reinforcing existing beams in the existing building. <P>SOLUTION: The aseismatic reinforcing method comprises steps of: newly providing a beam joint part 1 of steel structure including a column-beam joint part 10 of the existing building, around the column-beam joint part 10; filling grout in the new beam joint part 1 of steel structure to integrate the beam joint part 1 with an existing column 11; connecting new steel beams 3, 3 arranged on both sides of the existing beam 12, to the existing column 11 through the new beam joint part 1 of steel structure; and joining the new steel beams 3 integrally to existing floor slabs 13 or the existing beam 12. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention belongs to the technical field of seismic strengthening method and seismic strengthening structure of existing buildings, and more specifically, the existing building which improves the seismic performance of the whole building by increasing the beam strength of existing beams without changing the appearance of existing buildings. The present invention relates to a seismic reinforcement method and a seismic reinforcement structure of a building.

  As for seismic reinforcement technology for existing buildings, an external type seismic reinforcement technology (so-called outer shell frame construction method) in which a reinforcing column beam frame is built outside the existing building and the existing building and the column beam frame for reinforcement are connected. Are disclosed variously (for example, refer to Patent Documents 1 to 4). On the other hand, various types of seismic reinforcement techniques for reinforcing columns and beams inside existing buildings are also disclosed (see, for example, Patent Documents 5 to 7).

Since the external type seismic reinforcement technology can be installed outdoors, there is an advantage that the existing building can be seismically strengthened while staying without narrowing the living space (for example, the patent filed earlier by the present applicant) (See paragraphs [0002], [0003], and [0013] etc. of Document 1).
However, since this external type seismic reinforcement technology builds (adds) a new reinforcing column beam structure outside the existing building, the existing building may not be allowed to be changed in design due to cultural assets, etc. There has been a problem that it cannot be adopted when the building is constructed close to the site boundary, or when the owner or resident of the building does not accept the change of the exterior of the building.

On the other hand, regarding the type of seismic reinforcement technique for reinforcing the pillars and beams inside the existing building, Patent Document 5 discloses, as shown in FIGS. At least a part of the plate located on the outermost peripheral side is removed, and a reinforcement frame 3 having rigidity higher than that of the existing frame 6 is newly provided at the removed part, and the reinforcement frame 3 and the existing frame 6 are connected to each other. A seismic reinforcement method is disclosed (see claim 1).
In Patent Document 6, as shown in FIG. 1 and the like of Patent Document 6, the slab 3 is penetrated through at least a part of the outer periphery of the existing columns 1 and 2, and the existing column 1 on the upper floor side and the lower column side A reinforcing method is disclosed in which a column tensile reinforcement 4 is added across the existing columns 2 and integrated with the existing columns 1 and 2 to improve the tensile strength of the existing columns 1 and 2 (claim 1 and the like). reference).
In Patent Document 7, as shown in FIGS. 2a to 2c of the same document 7, an additional beam joining structure for reinforcing the existing building 20 by joining the additional beam 10 to the existing beam 22a, The reinforcing bar 10 is fixed through the fixing means 12 on the surface opposite to the surface where the additional beam 10 of the existing beam 22 abuts through the reinforcing bar insertion hole 30 formed in the existing beam 22a. Is disclosed (see paragraphs [0022]-[0024]).

  Since the reinforcement methods according to Patent Documents 5 to 7 introduce the seismic reinforcement technology inside the building, the problems that occur in the external-type seismic reinforcement technology as described above do not occur.

JP-A-9-203217 JP-A-11-62264 JP 2004-169504 A JP-A-2005-290774 JP-A-11-152905 JP 2004-116123 A JP 2006-122502 A

The reinforcement method according to Patent Document 5 is carried out by removing a part of the existing beam that constitutes the existing frame, so that the construction becomes very large, the construction cost increases, and the construction period is prolonged. It was. In addition, since many of the existing beams that have been removed become industrial waste, it is a point that should be improved in today's environment where global environmental issues are regarded as important.
Since the reinforcing method according to Patent Document 6 is implemented by effectively using the existing frame, the problem according to Patent Document 5 does not occur. However, it is doubtful whether the required reinforcement effect can be fully exhibited by simply adding a steel plate or fiber sheet to the surface of the column beam joint of the existing frame.
In the reinforcing method according to Patent Document 7, the RC beam is added to the side surface of the existing beam. Therefore, the building weight is significantly increased, and the mechanical performance of the existing frame may be reduced. In addition, work such as formwork, reinforcement, concrete placement, etc. is necessary and large, and there is room for improvement both economically and in terms of construction period.

  The object of the present invention is a seismic reinforcement technology that reinforces the existing beams inside the existing building, while not only making effective use of the existing frame, but also providing sufficient reinforcement effect without requiring extensive construction work. It is to provide a seismic reinforcement method and a seismic reinforcement structure for an existing building, which can be used in the present invention, and have excellent workability and economy.

As a means for solving the problems of the background art, the seismic reinforcement method for an existing building according to the invention described in claim 1 is as shown in FIGS. A step of newly installing a steel beam joint 1 including the same beam joint 10 around the periphery;
Filling the grout 2 in the beam joint 1 of the newly constructed steel structure, and integrating the beam joint 1 and the existing column 11;
Connecting the new steel beams 3 and 3 arranged on both sides of the existing beam 12 to the existing columns 11 via the beam connection part 1 of the new steel structure;
As shown in FIGS. 6 and 7, the new steel beam 3 is integrally joined to the existing floor slab 13 or the existing beam 12.

  The invention described in claim 2 is the method for seismic reinforcement of an existing building according to claim 1, wherein the existing beam building 1 is installed in the column beam joint 10 of the existing building prior to the new construction. The existing floor slab 13 around the pillar 11 is removed.

  The invention described in claim 3 is the seismic reinforcement method for an existing building described in claim 1 or 2, wherein the newly-installed steel-structured beam joint 1 has its upper and lower surfaces respectively identical to the outer periphery of the existing column 11. It is formed by flat diaphragms 5 and 6 divided into a plurality of shapes surrounding the existing pillar 11, and the side surface is formed by a concave plate 7 having a notch corresponding to the cross-sectional shape of the existing beam 12. It is a rectangular parallelepiped part, and the column beam joint part 10 of the existing building is included in the structure which mounts the diaphragm 5 of the said upper surface on the upper surface of the said existing beam 12. It is characterized by the above-mentioned.

  The invention described in claim 4 is the seismic reinforcement method for an existing building described in claim 3, wherein the newly installed steel-frame beam joint portion 1 is constructed after the post-construction anchor 9 is applied to the joint portion of the existing column 11. A rectangular parallelepiped portion whose upper surface is opened is formed by the diaphragm 6 on the lower surface and the side plate 7 having the stud bolt 8, and the grout 2 is filled into the rectangular parallelepiped portion from the opening, and then the opening is filled with the diaphragm on the upper surface. 6 and is integrated into the existing pillar 11.

The earthquake-proof reinforcement structure of the existing building according to the invention described in claim 5 is:
Around the column beam joint 10 of the existing building, a steel beam joint 1 including the column beam joint 10 is newly installed.
Filling the grout 2 in the beam joint 1 of the newly constructed steel structure and integrating the beam joint 1 and the existing column 11;
The newly installed steel beams 3 and 3 arranged on both sides of the existing beam 12 are connected to the existing column 11 via the beam connection portion 1 of the newly installed steel structure,
The new steel beams 3 and 3 are integrally joined to the existing floor slab 13 or the existing beam 12.

  The invention described in claim 6 is the seismic reinforcement structure for an existing building according to claim 5, wherein the beam connection portion 1 of the newly installed steel structure has an upper surface that is an outer periphery of the existing column 11 on the upper surface of the existing beam 12. Are formed by a flat diaphragm 5 divided into a plurality of shapes surrounding the existing pillar 11, and the side surface is formed by a concave plate 7 having a cutout portion corresponding to the cross-sectional shape of the existing beam 12, The lower surface is formed on the outer periphery of the existing column 11 at the lower end level of the plate 7 by a flat diaphragm 6 divided into a plurality of shapes surrounding the existing column 11 to form a rectangular parallelepiped portion.

  According to the seismic strengthening method and seismic strengthening structure of an existing building according to the present invention, it is a seismic strengthening technique of the type that reinforces an existing beam inside an existing building, and not only makes effective use of an existing frame but also a large-scale construction. Therefore, the required reinforcing effect can be sufficiently exhibited.

  Specifically, according to the seismic reinforcement method for an existing building described in claims 1 to 4, it can be carried out without impairing the design appearance of the existing building as compared with an external type seismic reinforcement technology. Since most of the reinforcement work can be done in the ceiling, the impact on the residents after completion is small. The existing pillars that make up the existing frame, as well as the existing beams, can be effectively utilized without removing any existing beams, so it is reasonable, and is economical and environmentally friendly. Moreover, since the main reinforcing material is implemented with the steel structure, it can be implemented while suppressing an increase in building weight as much as possible. Furthermore, since it can be carried out without carrying out large-scale work such as formwork work, bar arrangement work, concrete placement work, etc., it is very excellent in economic efficiency and workability.

  According to the seismic reinforcement structure of the existing building described in claims 5 and 6, since the new steel beam is provided on both sides of the existing beam to reinforce, the existing steel beam is localized by the new steel beam even when the existing beam is brittle. It is possible to dramatically improve the beam strength, such as preventing destructive collapse. Therefore, it greatly contributes to the improvement of the seismic performance of the entire building.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a plan sectional view schematically showing the entire seismic reinforcement structure of an existing building according to the present invention, and FIG. 2 is an elevation sectional view thereof. FIG. 3 is a perspective view showing a pivotal part of the seismic reinforcement structure for an existing building according to the present invention. FIG. 4 is a vertical sectional view showing the pivot part, and FIG. 5 is a plan sectional view showing the pivot part.

As shown in FIGS. 1 to 5, the seismic reinforcement structure for an existing building according to the present invention is a steel-frame-structured beam joint including the column-beam joint 10 around the column-beam joint 10 of the existing building. 1 is newly established.
The beam joint 1 and the existing column 11 are integrated by filling the grout 2 in the beam joint 1 of the newly-constructed steel structure.
New steel beams 3 and 3 arranged on both sides of an existing beam (including an existing large beam) 12 are connected to an existing column 11 via the beam connection portion 1 of the new steel structure.
The new steel beams 3 and 3 are integrally joined to the existing floor slab 13 (see FIG. 6) or the existing beam 12 (see FIG. 7) (invention of claim 5).
Incidentally, reference numeral 4 in the figure denotes a bracket.

As shown in FIG. 1, the steel beam connecting portion 1 according to the present embodiment is newly installed in the column beam connecting portion 10 excluding the one located on the outermost peripheral side among the column beam connecting portions 10 of the existing building. is doing. In addition, as shown in FIG. 2, it is newly installed in the column beam joint 10 on the intermediate floor excluding the top floor. This is a consideration for not changing the appearance of the existing building.
In addition, the site | part which provides the beam connection part 1 of a steel frame structure is not limited to the example of illustration, It is sufficient if it provides and implements only in the column beam connection part 10 which needs a seismic reinforcement structurally. However, it is necessary to provide at least two locations of adjacent beam-column joints on the same floor.
Moreover, even if it is the column beam junction part 10 located in the outermost periphery side, this invention can be applied, when it is provided apart from the outer peripheral wall of the existing building.
Incidentally, the beam-column joint 10 shown in FIG. 3 illustrates the beam-beam joint 10 located at the center of the beam-column joint 10 in FIG.

  The newly formed steel structure beam joint 1 is divided into a plurality of shapes in the shape surrounding the existing column 11 on the outer periphery of the existing column 11 on the upper surface of the existing beam 12 (in this embodiment, the U-shaped 2 The flat plate diaphragm 5 is divided and the side surface is formed of a concave plate 7 having a cutout portion corresponding to the cross-sectional shape of the existing beam 12, and the lower surface is the existing level at the lower end level of the plate 7. A rectangular parallelepiped portion is formed on the outer periphery of the column 11 by a flat diaphragm 6 divided into a plurality of shapes (in this embodiment, divided into two U-shapes) surrounding the existing column 11 (claim 6). invention).

Each of the above-described constituent elements 5, 6, and 7 constituting the steel-frame-structured beam joint 1 is generally manufactured from a processed steel plate product or a cast steel product.
Specifically, each of the upper diaphragm 5 and the lower diaphragm 6 is made of a flat plate member that is divided into at least a half, and surrounds the outer periphery of the existing pillar 11 as shown in FIGS. It is implemented by forming a rectangular frame shape (a bowl shape). In addition, the upper diaphragm 5 and the lower diaphragm 6 are implemented in the same shape as seen from the plane direction.
The plate 7 has a notch portion corresponding to the cross-sectional shape of the existing beam 12 in the upper half thereof, and is formed into a rectangular tube shape that surrounds the outer periphery of the existing column 11 with a necessary clearance. is doing. In the plate 7 according to the present embodiment, the left and right ends of the four concave plates 7 are joined to the ends of the adjacent plates 7 by a joining means such as welding. Further, the contact portions between the upper and lower diaphragms 5 and 6 and the plate 7 are also joined by a joining means such as welding.

The steel structure beam joint 1 and the existing column 11 having the above-described structure are formed in the groove 2 formed by the lower diaphragm 6 and the plate 7 constituting the beam joint 1 and the outer surface of the existing column 11. Is integrated.
Specifically, in this embodiment, as shown in FIGS. 4 and 5, the grout 2 is filled only in the L-shaped gaps at the respective corners of the grooves formed in a square shape when viewed from the plane. is doing.
Incidentally, reference numerals 7 a and 7 b in the figure are reinforcing rib plates that also serve to prevent leakage of the grout 2, and are provided vertically and horizontally on the inner surface of the plate 7. Further, in order to improve adhesion to the grout 2 and to reliably transmit the horizontal force, the stud 7 is provided on the inner surface of the plate 7 and the post-installed anchor 9 is not interfered with the outer surface of the existing column 11. Established and implemented.

  Note that the reason why the grout 2 is filled only in the L-shaped gap is because of consideration of the economy and sufficient rigidity in view of the mounting portion of the bracket 4 and structural mechanics. The grout 2 can be filled so as to fill the entire groove. In this case, the lower portion of the reinforcing rib plate 7a is cut out, or a hole through which the grout 2 is passed is provided in the lower portion.

New steel beams 3 and 3 arranged in parallel on both sides of the existing beam 12 are steel structures newly installed in adjacent column beam joints 10 and 10 on the same floor via brackets 4 provided at both ends in the axial direction. This is performed by joining the upper and lower diaphragms 5 and 6 forming the upper and lower surfaces of the beam joint portion 1 so that a horizontal force can be transmitted. The newly installed steel beams 3 and 3 have the same shape and size, and are provided in a line-symmetrical arrangement with the existing beams 12 as symmetry axes in the vicinity of the left and right ends of the plate 7 of the steel beam joint 1. It is preferable in terms of structural mechanics. Incidentally, the new steel beams 3 and 3 are not particularly new, and a commercially available steel such as H-shaped steel or I-shaped steel is preferably used.
In addition, although the joining means with the newly installed steel beam 3, the bracket 4, and the diaphragms 5 and 6 according to the present embodiment is carried out by welding, it is not limited to this, and it is integrated by means such as bolting or riveting. Of course, they can be joined.

Moreover, the new steel beams 3 and 3 which concern on a present Example are integrated via the existing floor slab 13 and the grout 14, as shown in FIG. At the site where the grout 14 is filled, the stud bolt 8 is provided on the upper surface of the new steel beam 3 and the post-construction anchor 9 is provided on the lower surface of the existing floor slab 13 so that a device for transmitting the horizontal force is provided. ing. Incidentally, reference numeral 15 in FIG. 6 denotes a split preventing muscle.
In addition, as shown in FIG. 7, the new steel beams 3 and 3 can be integrated with the existing beam 12 by filling grout (concrete) 14 on both side surfaces of the existing beam 12.

Therefore, according to the seismic reinforcement structure of the existing building having the above-described structure, although it is a seismic reinforcement technology of the type that reinforces the existing beam 12 inside the existing building, not only the existing frame but also the large construction is required. Therefore, the required reinforcing effect can be sufficiently exhibited.
Specifically, since the new steel beams 3 and 3 are provided and reinforced on both sides of the existing beam 12, even if the existing beam 12 undergoes brittle fracture, the new steel beams 3 and 3 prevent local destructive collapse. The beam strength can be improved dramatically. Therefore, it greatly contributes to the improvement of the earthquake resistance of the entire building.

  Here, the seismic reinforcement method for realizing the seismic reinforcement structure of the existing building having the above-described configuration will be described.

  In this seismic retrofit method for an existing building, first, the existing floor slab 13 around the existing column 11 is removed by an amount necessary for newly installing the steel beam joint 1 and the bracket 4 (see FIG. 4). Invention of Claim 2). In addition, this process is unnecessary when it implements in the site | part where the column beam junction part 10 is previously exposed, such as what is called a blow-off structure.

Next, among the existing beams 12 of the existing building, the steel beam-structured beam joints including the column beam joints 10 are respectively included in the column beam joints 10 and 10 in which the existing beams 12 that require seismic reinforcement are installed. 1 is newly established.
The steel structure beam joint 1 has a flat plate shape in which the upper and lower surfaces are divided into a plurality of shapes (in this embodiment, divided into two U-shapes) on the outer periphery of the existing column 11 so as to surround the existing column 11. The diaphragm 5 is formed as a rectangular parallelepiped portion formed by a concave plate 7 having a notch corresponding to the cross-sectional shape of the existing beam 12, and the upper diaphragm 5 is formed on the upper surface of the existing beam 12. The column beam joint 1 of the existing building is included in the configuration of placing on the upper surface (on the end side) (the invention according to claim 3).

  Incidentally, the diaphragm 5 on the upper surface is placed on the upper surfaces of the four existing beams 12 joined in a cross shape around the existing columns 11 when viewed from the planar direction, with respect to the column beam joint 10 according to FIG. However, the present invention is not limited to this. As shown in FIG. 1, the three existing beams 12 joined in a T shape around the existing column 11 are arranged in accordance with the installation site of the column beam joint 10 provided with the steel beam joint 1. There may be a case where it is carried out with a configuration where it is placed on the upper surface, or a case where it is carried out with a configuration where it is placed on the upper surface of the two existing beams 12 joined in a perpendicular direction.

Next, the grout 2 is filled in the newly-formed steel beam-structured beam joint portion 1, and the beam joint portion 1 and the existing column 11 are integrated.
As a method of integrating the beam joint 1 and the existing column 11, in this embodiment, after the post-construction anchor 9 is installed at the joint of the existing column 11, the side surface having the diaphragm 6 on the lower surface and the stud bolt 8 is provided. A rectangular parallelepiped portion whose upper surface is opened with the plate 7 is formed, and after filling the grout 2 into the rectangular parallelepiped portion from the opening portion, the opening portion is closed with the diaphragm 5 on the upper surface to be integrated with the existing pillar 1 (claim). 4).
In this embodiment, the grout 2 filled in the rectangular parallelepiped portion (groove portion) is filled only in the L-shaped gaps of the corner portions of the groove portions formed in a square shape. However, the present invention is not limited to this. Alternatively, the filling may be performed so that the entire groove is filled (see paragraphs [0023] and [0024] above).

  Each of the upper diaphragm 5 and the lower diaphragm 6 is made into a regular shape by integrally joining the contact portions of the flat divided pieces divided into two in half by welding or the like. Similarly, the plate 7 is also joined to the abutting portion with the adjacent plate 7 integrally by means of welding or the like to form a square tube. The contact portions between the upper and lower diaphragms 5 and 6 and the plate 7 are also integrally joined by means such as welding.

As described above, after confirming that the steel beam joints 1 and 1 provided in the adjacent column beam joints 10 and 10 are integrated with the existing pillar 11, the new steel beams 3 and 3 are connected to the existing beam. A horizontal force is applied to the upper and lower diaphragms 5 and 6 that form the upper and lower surfaces of the beam joint portion 1 of the steel structure via the brackets 4 provided in the axially symmetric arrangement with 12 as the symmetry axis. It joins so that transmission is possible. The new steel beam 3, the bracket 4, and the diaphragms 5 and 6 are joined by welding.
The bracket 4 according to the present embodiment is implemented with a height dimension such that the upper surface thereof is substantially flush with the upper surface of the upper diaphragm 5 and the lower surface thereof is substantially flush with the lower surface of the lower diaphragm 6. Yes. In addition, the new steel beam 3 is implemented with a height smaller than that of the bracket 4 in consideration of economy.

Subsequently, the new steel beams 3 and 3 are respectively connected to the adjacent steel beam joints 1 and 1, and then the new steel beams 3 and 3 are integrated with the existing floor slab 13 and the grout 14. The seismic reinforcement method is finished (see FIG. 6). When the grout 14 is filled, a metal plate or a wood plate is attached to prevent the grout 14 from leaking.
In addition, as shown in FIG. 7, the new steel beams 3 and 3 can be integrated with the existing beam 12 by filling grout (concrete) 14 on both side surfaces of the existing beam 12. In this case, since the new steel beams 3 and 3 and the existing floor slab 13 serve as both the side surface and the upper surface of the formwork, the grout 14 has a simple formwork structure in which a metal plate is attached to the lower surface level of the existing beam 12. The filling operation can be performed.

Therefore, according to the above-mentioned seismic reinforcement method for an existing building, although it is a type of seismic reinforcement technology that reinforces the existing beam 12 inside the existing building, it requires large-scale construction as well as effective use of the existing frame. The required reinforcing effect can be sufficiently exhibited without any problems.
Specifically, most of the reinforcement work can be done in the ceiling, so the impact on residents after completion is small. Since it is a type of seismic reinforcement technology that reinforces the existing beam 12 inside the existing building, it does not impair the design appearance of the existing building as compared with the external type seismic reinforcement technology. Since the existing pillar 11 constituting the existing frame can be used effectively without removing the existing beam 12 at all, it is rational and excellent in economic efficiency and environmental performance. Moreover, since the main reinforcing material is implemented with the steel structure, it can be implemented while suppressing an increase in building weight as much as possible. Furthermore, since it can be carried out without carrying out large-scale work such as formwork work, bar arrangement work, concrete placing work, etc., it is very excellent in economic efficiency and workability.

The embodiments have been described with reference to the drawings. However, the present invention is not limited to the illustrated embodiments, and design modifications and application variations that are usually made by those skilled in the art are within the scope of the technical idea of the invention. Note that it includes the range.
For example, the size of the steel structure beam joint 1 and the size of the newly installed steel beam 3 according to the present invention are appropriately changed in design according to the size of the frame of the existing building to be applied.

It is the plane sectional view showing roughly the whole seismic reinforcement structure of the existing building concerning the present invention. FIG. 2 is a vertical sectional view of FIG. 1. It is the perspective view which showed the principal part of the earthquake-proof reinforcement structure of the existing building which concerns on this invention. It is the sectional elevation which showed the principal part of the earthquake-proof reinforcement structure of the existing building which concerns on this invention. It is the plane sectional view showing the principal part of the seismic reinforcement structure of the existing building concerning the present invention. It is the elevation sectional view showing the joined state of the newly installed steel beam and the existing floor slab according to the present invention. It is the elevation sectional view showing the joined state of the new steel beam and the existing beam concerning the present invention.

Explanation of symbols

1 New steel beam joint 2 Grout 3 New steel beam 4 Bracket 5 Upper diaphragm 6 Lower diaphragm 7 Plate 7a, 7b Reinforcement rib plate 8 Stud bolt 9 Post-installed anchor 10 Existing column beam joint 11 Existing column 12 Existing beam 13 Existing floor slab 14 Grout (concrete)
15 Anti-split muscle

Claims (6)

A process of newly installing a steel-structured beam joint that encloses the beam-column joint of the existing building,
Filling the grout into the beam joint of the new steel structure, and integrating the beam joint and the existing column;
Connecting the new steel beams arranged on both sides of the existing beams to the existing columns via the beam joints of the new steel structure;
A step of integrally joining the new steel beam to an existing floor slab or an existing beam;
A method for seismic reinforcement of an existing building, characterized by comprising:   2. The earthquake resistance of an existing building according to claim 1, wherein an existing floor slab around the existing column is removed prior to newly installing a steel beam joint at the column beam joint of the existing building. Reinforcement method.   The newly constructed steel-frame beam joint is formed by a flat diaphragm divided into a plurality of shapes in a shape surrounding the existing column on the outer periphery of the existing column, and the side surface is a cross section of the existing beam. It is a rectangular parallelepiped part formed by a concave plate having a notch corresponding to the shape, and includes the column beam joint part of the existing building in a configuration in which the diaphragm of the upper surface is placed on the upper surface of the existing beam. The method for seismic reinforcement of an existing building according to claim 1 or 2, characterized by the above.   The newly established steel structure beam joint part is a rectangular parallelepiped part having an upper surface opened by a diaphragm on the lower surface and a side plate having a stud bolt after the post-construction anchor is applied to the joint portion of the existing column, The method for seismic reinforcement of an existing building according to claim 3, wherein after filling grout into the rectangular parallelepiped portion from the opening, the opening is closed with a diaphragm on the upper surface and integrated into an existing column. A steel-frame beam joint that includes the beam-column joint is newly installed around the beam-column joint of the existing building.
The beam joint and the existing pillar are integrated by filling grout in the beam joint of the newly-constructed steel structure,
The new steel beam placed on both sides of the existing beam is connected to the existing column via the beam connection part of the new steel structure,
A seismic reinforcement structure for an existing building, wherein the new steel beam is integrally joined to an existing floor slab or an existing beam.   The newly constructed steel-frame beam joint is formed of a plate-shaped diaphragm divided into a plurality of shapes that surround the existing column on the outer periphery of the existing column on the upper surface of the existing beam. The plate is formed of a concave plate having a notch corresponding to the cross-sectional shape of the beam, and the lower surface is divided into a plurality of shapes that surround the existing column on the outer periphery of the existing column at the lower end level of the plate. The seismic reinforcement structure for an existing building according to claim 5, wherein the structure is formed of a diaphragm to form a rectangular parallelepiped portion.

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