JP5755558B2 - Seismic reinforcement structure and method using compression braces - Google Patents

Description

  The present invention relates to a seismic reinforcing structure and a reinforcing method for a building using a compression brace.

Conventionally, as a seismic reinforcement method for RC structures (steel reinforced concrete structures) and SRC structures (steel reinforced concrete structures), a reinforcement method using braces with a steel frame is often used. This seismic reinforcement method has the following characteristics.
・ The feeling of blockage can be reduced compared to the case where RC walls are reinforced and seismic reinforced.
-When joining braces with steel frames to existing frames, indirect joining is often used in which mortar filling is performed using post-installed anchors and studs with heads.

JP 2009-249833 A JP 2008-2133 A

However, if the brace with a steel frame is indirectly joined to the existing frame using the post-construction anchor as in the conventional seismic reinforcement method described above, the following problems occur in the construction.
・ Noise, vibration and dust are generated when post-installed anchors are installed. That is, when a tensile force is applied to the brace, it is necessary to use a large number of post-installed anchors or to embed them deeply in order to reliably transmit stress to the existing building frame. Therefore, the problems of noise, vibration, and dust generation when placing post-installed anchors are large.
・ As each work of formwork assembly, filling / curing of non-shrink mortar, and formwork disassembly is required, the construction period becomes longer and costs increase.

As a solution to these problems, using a compression brace, the core material is divided into a pair of split core materials at a portion constrained by a length direction restraint material, and between the pair of split core materials, A steel plate perpendicular to the length direction was proposed over a restraint material (Japanese Patent Application No. 2010-279267).
However, since both split cores are movable in the length direction with respect to the constraining material, the split cores may drop off during transportation or construction, or initial irregularities may occur due to displacement in the length direction. There is a fear. Even if there is a slight displacement in the longitudinal direction of the split core material, if there is a gap between the split core material and the steel plate placed in the center, even if the gap is a slight gap of less than 1 mm, Compressive stress cannot be transmitted at a minute displacement, and the performance of the compression brace cannot be ensured. For this reason, it is necessary to troubleshoot the initial irregularity.

The object of the present invention is to use a compression brace that does not impose a tensile force, so that the joint with the existing building can be simplified, and seismic reinforcement can be performed with simple construction and a short construction period. To provide a seismic strengthening structure and a seismic strengthening method that are free from dust problems, prevent adverse effects due to misalignment of the core material, and prevent the core material from dropping or initial imperfection during transportation or construction. It is.
Another object of the present invention is to reduce the amount of steel used.

  The seismic reinforcement structure using a compression brace according to the present invention is a structure in which an existing building is reinforced with braces, and the brace extends along both sides of the core material, both ends of which are connected to the frame of the existing building. A compression brace having a constraining material disposed and constraining buckling of the core material, the core material being divided into a pair of split core materials at a portion constrained by a restraining material in a length direction, A steel material perpendicular to the length direction is interposed between the pair of split core materials across the restraint material, and the steel material is joined to one of the split core materials.

The brace is usually used for a load of a tensile force. According to this configuration, the brace is a compression brace composed of a pair of split cores divided in the middle in the length direction. The burden of power can be eliminated. By eliminating the burden of tensile force, it is possible to simplify the joining with the frame of an existing building. That is, when the tensile force is applied to the brace, in the case of an existing structure of RC structure or SRC structure, it is necessary to use a large number of anchors or to provide deep anchors in order to reliably transmit stress at the joint. . However, in the brace that bears only the compressive force, the stress can be transmitted by the bearing pressure, so that the braces can be connected with a small number of anchors. Therefore, it is possible to simplify the joining with the existing building frame. Therefore, earthquake-proof reinforcement can be performed with a simple construction and a short construction period, the cost can be reduced, and the problems of noise, vibration and dust associated with the construction do not occur. Moreover, since the said brace consists of a core material and the restraint material arrange | positioned along the both surfaces, it can bear strong compressive force, without producing a buckling of a restraint material.
The core material is divided in the middle part, but since the divided part is the part where the restraint material is restrained, it is prevented from bending at the split part when receiving the compressive force and bears a strong compressive force. can do.
In addition, a steel material perpendicular to the length direction is interposed between the pair of split core materials over the restraint material, and the area that can be contacted by this steel material increases, so the core material is misaligned. Adverse effects can be mitigated.

  Since the steel material is bonded to any one of the split core materials, the split core material to which the steel materials are bonded is prevented from moving to the end side of the compression brace. Therefore, by transporting and building the compressed braces in an oblique or standing posture with the steel core joined, the split core can be prevented from falling off during transportation and building. In addition, the occurrence of initial irregularities in which the split core material is displaced in the length direction and a gap is generated between the split core material and the steel material is reduced. Therefore, it is prevented that the compressive stress cannot be transmitted in a minute displacement and the performance of the compression brace cannot be secured, and the reliability of securing the performance of the compression brace is improved. In addition, even if the steel material is joined to one split core material, the other split core material can move in a direction away from the steel material, so that the function of eliminating the burden of tensile force is impaired by the core material split. There is nothing.

In the present invention, as a steel frame to be arranged in a portion consisting of a beam in a frame of an existing building and a pair of columns extending below the beam on both sides of the beam, an upper steel frame material along the beam is provided, and the compression brace is provided. Two of them may be arranged in an inverted V shape, and the upper ends of these two compression braces may be joined to the upper steel frame member.
Thus, by using only the upper steel frame material as the steel frame material, the amount of steel material used can be reduced and the cost can be reduced. Even if only the upper steel frame material is used as the steel frame, as described above, the compression brace is used as the brace, and two of the compression braces are arranged in an inverted V shape as described above, so that the necessary seismic reinforcement can be performed.

  In this invention, you may join a reinforcement board to the surface of the division | segmentation side edge part of the said pair of division | segmentation core material in the said compression brace. By the joining of the reinforcing plates, the core material can be prevented from shifting and out-of-plane deformation.

The seismic reinforcement method using a compression brace according to the present invention is a method of reinforcing an existing building by connecting both ends of the brace to a frame of an existing building, and the core material having both ends connected to the frame of the existing building as the brace. And a compression brace that is disposed along both sides of the core material and that has a restraining material that restrains the buckling of the core material and supports the compression force. In this compression brace, the core material is divided into a pair of split core materials at a portion constrained by a length direction restraint material, and a steel material perpendicular to the length direction is interposed between the pair of split core materials. In this case, the steel material is joined to one of the divided core materials.
According to this seismic reinforcement method, the compression brace is used in the same way as described above for the seismic reinforcement structure of the present invention. It can be done at a low cost, and there are no problems with noise, vibration, or dust associated with construction. Further, it is possible to prevent adverse effects due to misalignment of the core material, and prevent the core material from dropping or initial irregularity during transportation or construction.

  The seismic reinforcement structure using a compression brace according to the present invention is a structure in which an existing building is reinforced with braces, and the brace extends along both sides of the core material, both ends of which are connected to the frame of the existing building. A compression brace having a constraining material that is arranged and restrains buckling of the core material, and the core material is divided into a pair of divided core materials in the middle in the length direction, so that a joint portion with an existing building is provided. It can be simplified and can be seismically reinforced with simple construction and a short construction period, and can be reinforced without causing problems of noise, vibration and dust associated with construction. Furthermore, since the steel material perpendicular to the length direction is interposed between the pair of split core materials over the restraint material, adverse effects due to the misalignment of the core material can be mitigated. Since the steel material is joined to any one of the split core materials, it is possible to prevent the core material from falling off or initial imperfection during transportation or construction.

  The seismic reinforcement method using a compression brace according to the present invention is a method of reinforcing an existing building by connecting both ends of the brace to a frame of an existing building, and the core material having both ends connected to the frame of the existing building as the brace. And a compression brace that is disposed along both surfaces of the core material and restrains buckling of the core material and supports a compressive force, and the compression brace is disposed in the length direction of the core material. Since it was divided into a pair of split cores in the middle of the construction, the joint with the existing building can be simplified, and earthquake-proof reinforcement can be performed with a short construction period with simple construction, and noise, vibration, and dust associated with construction It can be seismically reinforced without causing any problems. Furthermore, since the steel material perpendicular to the length direction is interposed between the pair of split core materials over the restraint material, adverse effects due to the misalignment of the core material can be mitigated. Since the steel material is bonded to any one of the split core materials, it is possible to prevent the core material from dropping or initial irregularity during transportation or construction.

It is a front view of the building frame using the earthquake-proof reinforcement structure of one embodiment of this invention. It is the external appearance perspective view and sectional drawing of the compression brace in the seismic reinforcement structure. It is operation | movement explanatory drawing which shows the state at the time of compression of the compression brace, and normal time. It is effect | action explanatory drawing which shows the state at the time of tension | pulling of the compression brace. It is operation | movement explanatory drawing which shows the whole compression brace. (A) is sectional drawing at the time of compression of a compression brace, (B) is sectional drawing at the time of the tension | pulling of the compression brace. (A) is sectional drawing at the time of compression of the other example of a compression brace, (B) is sectional drawing at the time of tension | tensile_strength of the compression brace. It is a perspective view of the further another example of a compression brace. It is explanatory drawing of the core shift | offset | difference at the time of compression when there is no reinforcement board in the surface of the division | segmentation side edge part of the core material of a compression brace. It is an expanded sectional view of the A section in FIG. It is an expanded sectional view of the B section in FIG. It is an expanded sectional view of the C section in FIG. It is a front view which shows the example of application to the building frame of this embodiment. It is a front view which shows the further another example of application to the building frame of this embodiment. It is a front view which shows the further another example of application to the building frame of this embodiment. It is a front view which shows the further another example of application to the building frame of this embodiment.

  An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a partial front view showing a frame structure of an existing building to which the seismic reinforcement structure of this embodiment is applied. The seismic reinforcement structure of this embodiment is a structure that reinforces an existing building using the compression braces 2A and 2B. As shown in the figure, the building frame has a beam 30 horizontally mounted between two adjacent columns 20, 20, and the upper part between the columns 20, 20 on both sides along the lower surface of the beam 30. A steel frame material 1 is provided. Below the upper steel frame member 1, two compression braces 2A and 2B are arranged in an inverted V shape. That is, the first compression brace 2 </ b> A is provided between the intermediate portion of the upper steel frame member 1 and the lower end of the one column 20, and between the intermediate portion of the upper steel frame member 1 and the lower end of the other column 20. A second compression brace 2B is provided. The building frame is RC or SRC.

  The upper steel frame member 1 is made of, for example, H-shaped steel as shown in FIG. 10 showing an enlarged view of the portion A in FIG. 1 and FIG. 11 showing an enlarged sectional view of the portion B in FIG. End plates 1b are provided at both ends. The mortar 12 is filled between the column 20 and the beam 30 and the upper steel frame member 1, and the end plates 1b at both ends of the upper steel frame member 1 are bolted with bolts 13 and nuts (not shown) as shown in FIG. The upper steel frame member 1 is joined to the building frame by joining the pillar 20 and joining the plurality of portions of the web 1a of the upper steel frame member 1 to the beam 30 with bolts 13 and nuts in the same manner. Each bolt 13 is an anchor such as a hole-in anchor provided in the post-construction on the beam 30 or the pillar 20, for example.

  One end of each of the first and second compression braces 2A and 2B is joined to the lower end of each column 20 via a connecting member 3a, and the other end of each of the compression braces 2A and 2B is connected via another connecting member 3b. It is joined to the middle part of the upper steel frame material 1.

Each of the compression braces 2A and 2B is a member that resists a horizontal force applied to the building frame. As shown in FIG. It has a pair of restraining materials 4 and 4 for restraining bending. The core material 3 is a strip-shaped flat steel plate, and is made of a steel material having a low yield point, such as an SN material (rolled steel material for building structures) or a LYP material (extremely low yield point steel material).
The restraint material 4 is configured by filling a mortar or concrete 6 in a channel steel material 5 that opens toward the core material 3, for example. An unbond material 9 made of a viscous elastic body is interposed between the core material 3 and the restraint material 4. Spacers 19 are provided on both side surfaces of the core material 3 to secure a gap between the pair of constraining materials 4 and 4 facing each other. The spacer 19 is made of a linear steel material or rubber material, but may be omitted.
The connecting member 3 a is provided at both ends of the core material 3. The connecting member 3 a is a plate-like member and may be joined to the core material 3 or integrally formed with the core material 3. The connecting member 3 a is provided with reinforcing ribs 3 aa on both sides along the longitudinal direction, and the reinforcing ribs 3 aa protrude from slit portions provided in the vicinity of the ends of the channel steel material 5 of the restraining material 4.

As shown in FIG. 6, the core material 3 is divided into a pair of divided core materials 3 </ b> A and 3 </ b> A at a midway portion in the length direction, for example, at the center, within a range restrained by the restraint material 4. A steel plate 7 perpendicular to the length direction is interposed between the pair of split core materials 3A and 3A across the restraint material 4. In the example of FIG. 6, the steel plate 7 is extended both vertically and horizontally to a position where it abuts against the channel steel material 5 that is the outer member of the restraint material 4. A portion of the mortar or concrete 6 of the restraint 4 is divided into left and right via a steel plate 7.
In addition to this, as shown in FIG. 7, the steel plate 7 may be extended to a position where the channel steel material 5 is cut through and protruded to the outside of the restraint material 4. In this case, the whole restraining material 4 is divided into left and right parts.

  The steel plate 7 is joined to the one split core material 3A by the joining means 31. The joining means 31 is, for example, a welded portion such as fillet welds on the entire circumference of the end surface that comes into contact with the steel plates 7 of the divided core members 3A and 3A. When a later-described reinforcing plate 8 is joined to the surface of the divided side end portion of the divided core member 3 </ b> A, the steel plate 7 may be welded to the reinforcing plate 8 by the joining means 31. The joining means 31 may be adhesive bonding, bolts, or the like in addition to welding. The steel plate 7 may be joined to either of the pair of split core materials 3A and 3A, but it is preferable to join the split core material 3A which is the lower side in the building. When the compression braces 2A and 2B have no vertical direction except for the joining of the steel plates 7, that is, when the top and bottom directions are not used, the member direction mark 32 indicates which is the upper or lower side. It is preferable to apply a portion (see FIG. 2) that can be seen from the outside of the compression braces 2A and 2B, for example, the outer surface of the restraint material 4. The split core material 3A that is not joined to the steel plate 7 is also brought into contact with the steel plate 7 when the construction is completed, leaving the gap zero.

  Reinforcing plates 8 are joined to both surfaces of the split side end portions of both split cores 3A by welding as shown in FIG. When the reinforcing plate 8 is provided, the portion covered with the unbond material 9 is preferably a portion excluding the joint portion of the reinforcing plate 8 on both surfaces of both split core materials 3A.

FIG. 6 is a sectional view taken along the line VI-VI of the compression brace 2A in FIG. 1 separately for compression, normal and tension. FIG. 3 is an explanatory view showing a state during compression and normal state, and FIG. 4 is an explanatory view showing a state during tension. In this compression brace 2A, since the core material 3 is composed of a pair of divided core materials 3A and 3A divided in the middle part in the length direction, both of them are applied when a compressive force is applied as shown in FIGS. The ends of the split cores 3A and 3A are brought into contact with each other through the steel plate 7 and can transmit a compressive force. However, when they are pulled as shown in FIGS. 6B and 4, they are joined to the steel plate 7. The end portion of the non-divided split core material 3A is pulled away from the steel plate 7, and the pair of split core materials 3A and 3A are separated from each other, so that no tensile force is applied.
As described above, the pair of divided core members 3A and 3A are brought into contact with or separated from each other by the applied load, but the steel plate 7 is interposed between the two divided core members 3A and 3A. The end faces of 3A and 3A are in contact with the steel plate 7. Therefore, even if the core material 3 is misaligned in the thickness direction or the like, the influence of the misalignment can be alleviated and a reliable compression force can be transmitted. The same applies to the other compressed brace 2B. The same applies to the configuration example of FIG. 7 in which the steel plate 7 is protruded to the outside of the restraint material 4.

  Further, in these compression braces 2A and 2B, the reinforcing plates 8 are joined to both sides of the split side end portion of the split core member 3A as shown in FIG. 8, so that the guide for displacement of the split core member 3A in the longitudinal direction is joined. Thus, the vertical misalignment of the split core material 3A and the out-of-plane deformation at the end can be suppressed. Incidentally, when the divided core material 3A does not have the reinforcing plate 8, the cores between the left and right divided core materials 3A, 3A as shown in FIG. 9A are the same as in FIG. 9B. Furthermore, there is a possibility of misalignment by the thickness of the unbond material 9. When the reinforcing plates 8 are joined to both surfaces of the split side end portion of the split core material 3A, such misalignment can be suppressed.

Since the steel plate 7 interposed in the divided portion is joined to any one of the divided core members 3A, the problems during transportation and construction are solved as follows. That is, the divided core material 3A to which the steel plate 7 is bonded is prevented from moving toward the end portions of the compression braces 2A and 2B with respect to the restraining material 4. Therefore, when the divided core material 3A to which the steel plate 7 is joined is transported and constructed in an oblique posture or a standing posture with the compressed braces 2A and 2B being transported and constructed, It is prevented from falling off.
In addition, in the completed state of the building method, it is necessary to bring the split core material 3A not joined to the steel plate 7 into contact with the steel plate 7 so that the gap between the steel plate 7 is zero, but both split core materials 3A, If both 3A are movable with respect to the restraint material 4, the split core material 3A may be displaced in the longitudinal direction during construction, and an initial irregularity in which a gap is generated between the split core material 3A and the steel plate 7 may occur. . If the gap is small, as shown in FIG. 5 (B), the compression brace, for example, the compression brace 2B, can transmit compressive stress due to the gap even in the case of an earthquake, even if an earthquake occurs. Therefore, the reinforcing effect cannot be obtained. When the deformation progresses and the split cores 3A and 3A come into contact with each other, the compressive force is transmitted to exert a reinforcing effect. In this embodiment, since one of the divided core members 3A is joined to the steel plate 7, the initial irregularity of the gap generation described above is prevented. Therefore, when an earthquake occurs as shown in FIG. Reinforcement effect is obtained by transmitting the compression force. Therefore, the reliability of securing the performance of the compression braces 2A and 2B is improved. Even if the steel plate 7 is joined to one split core 3A, the other split core 3A can move in the direction away from the steel plate 7 as described above. The function of eliminating the burden is not impaired.

  The connecting members 3a and 3b at both ends of both compression braces 2A and 2B are plate-like portions integrally formed at both ends of the core material 3, and FIG. 12 shows an enlarged cross-sectional view of a portion C in FIG. As described above, the end plates 10 and 11 are provided at the ends of the connecting members 3a and 3b. The end plates 10 and 11 are, for example, L-shaped bent at a right angle. The direction of the line that bisects the L-shaped bending angle is the length direction of the compression braces 2A and 2B. The end plates 10 and 11 protrude toward both sides of the connecting members 3a and 3b, but may protrude only on one side. These end plates 10 and 11 are provided with a plurality of bolt insertion holes.

  As shown in FIG. 12, the mortar 12 is filled between the column 20 and the beam 30 and the connecting member 3a at the lower end of both compression braces 2A and 2B, and the vertical piece of the end plate 10 provided on the connecting member 3a and By joining the horizontal piece to the column 20 and the beam 30 with bolts 13 and nuts (not shown) such as hole-in anchors, the lower ends of both compression braces 2A and 2B are connected to the existing building frame.

  As shown in FIG. 10, a mounting steel plate 14 that protrudes vertically downward from the web portion 1 a is provided in the middle portion of the upper steel frame member 1. By joining the vertical piece and the horizontal piece of the end plate 11 provided on the connecting member 3b at the upper ends of both the compression braces 2A and 2B to the mounting steel plate 14 and the web portion 1a of the upper steel frame member 1 with bolts 13. The upper ends of both compression braces 2A and 2B are connected to the existing building frame via the upper steel frame member 1. The vertical pieces of the end plates 11 of both the compression braces 2A, 2B are joined together with the mounting steel plate 14 with bolts 13 in an overlapping state.

According to the seismic reinforcement structure using the compression braces 2A and 2B having the above-described configuration, the stress transmission between the compression braces 2A and 2B and the existing building frame can be performed by supporting pressure through the upper steel frame member 1. By using the compression braces 2A and 2B, stress transmission by supporting pressure is made, and the tension force is not borne by the compression braces 2A and 2B. It can simplify the connection with the building frame. Thereby, since the number of anchors, such as the volt | bolt 13 used for post-construction, can also be reduced, a noise and vibration can be suppressed and a construction period can also be shortened.
Moreover, since only the upper steel frame material 1 is provided as a steel frame used in combination with the compression braces 2A and 2B, the amount of steel used can be reduced and the cost can be reduced. Even if only the upper steel frame material 1 is provided without providing the steel frame, the stress transmission between the compression braces 2A and 2B and the existing building frame can be performed via the upper steel frame material 1, and sufficient seismic reinforcement is provided. Can be done. Since the steel frame can be reduced to only the upper steel frame material 1, the number of anchors can also be reduced, leading to suppression of noise and vibration and shortening of the construction period. Since the number of mortar 12 filling places is also limited, it is possible to reduce costs by reducing mortar.

  FIG. 13: is a front view which shows an example which applied the seismic reinforcement structure of this embodiment to the building frame. In this building frame, the lower floor is a piloti, the upper floor has a bearing wall 40, and the seismic reinforcement structure of the embodiment is applied to the lower floor piloti. In this case, since the shear force P acting on the center of the beam 30 that receives the compression braces 2A and 2B can be borne by the load bearing wall on the upper floor, the seismic reinforcement by the compression braces 2A and 2B can be effectively performed.

  FIG. 14 is a front view showing an example in which the seismic reinforcement structure of this embodiment is applied to still another building frame. This building case is a case where there is no bearing wall in the building case of FIG. 13, and the seismic reinforcement structure of the embodiment is applied to the lower floor piloti, and as a reinforcing measure against the shearing force P in FIG. A buckling restraint column 15 is installed between the beams 30 on the third floor. The buckling restraint column 15 can divide the load on the beam 30. Also in this case, the seismic reinforcement by the compression braces 2A and 2B can be effectively performed.

  FIG. 15 is a front view showing an example in which the seismic reinforcement structure of this embodiment is applied to still another building frame. This building frame is also a case where there is no bearing wall in the building frame of FIG. 13, and the seismic reinforcement structure of the embodiment is applied to the lower floor piloti, and as a reinforcing measure against the shearing force P in FIG. A continuous fiber material 16 is installed on the beam 30. By providing the continuous fiber material 16 in this way, it is possible to reinforce the shear force from the compression braces 2A and 2B. The graph shown in the figure is a diagram of the bending moment applied to the beam 30 in this case.

  FIG. 16 is a front view showing an example in which the seismic reinforcement structure of this embodiment is applied to another building frame. This building frame is also a case where there is no bearing wall in the building frame of FIG. 13, and the seismic reinforcement structure of the embodiment is applied to the lower floor piloti, and as a reinforcement measure against the shearing force P in FIG. The same seismic reinforcement structure is installed upside down. Thereby, the shearing force P can be sent to the pillar 20 of an upper floor.

DESCRIPTION OF SYMBOLS 1 ... Upper steel frame material 2A, 2B ... Compression brace 3 ... Core material 3A ... Divided core material 4 ... Restraint material 7 ... Steel plate 8 ... Reinforcement plate 31 ... Joining means

Claims (5)

  A structure in which an existing building is reinforced with braces, and the braces are arranged along both sides of the core material, both ends of which are connected to the frame of the existing building, and restrain the buckling of the core material. The core material is divided into a pair of split core materials at a portion constrained by the length direction restraint material, and the length is between the pair of split core materials. An anti-seismic reinforcing structure using a compression brace, characterized in that a steel material perpendicular to the direction is interposed over a restraining material and the steel material is joined to one of the divided core materials.   2. The earthquake-proof reinforcement structure according to claim 1, wherein the steel material is welded to the one of the split cores.   3. The upper steel frame material along the beam is provided as a steel frame arranged in a portion consisting of a beam in a frame of an existing building and a pair of columns extending below the beam on both sides of the beam. An anti-seismic reinforcement structure comprising a compression brace in which two compression braces are arranged in an inverted V shape and the upper ends of the two compression braces are joined to the upper steel frame member.   4. The earthquake-proof reinforcement structure according to claim 1, wherein a compression plate is joined to a surface of a split-side end portion of the pair of split core members in the compression brace.   A method of reinforcing an existing building by connecting both ends of a brace to a frame of an existing building, and as the brace, both ends are connected to the frame of the existing building and arranged along both sides of the core A compression brace having a restraining material that restrains buckling of the core material and supporting a compressive force, and the compression brace is paired at a portion where the core material is restrained by a restraining material in a length direction. A steel material perpendicular to the length direction is interposed between the pair of split core materials across the restraint material, and the steel material is joined to one of the split core materials. A seismic reinforcement method using compression braces.

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