JP2019214881A - Buckling restrained brace - Google Patents

Abstract

To provide a buckling restrained brace which is suitable for being used incorporated in a frame of a wooden building, and can prevent a restrained plate from opening to the outside when a core material is about to be buckled.SOLUTION: A buckling restrained brace 50 includes: a plate-like core material 10 made of a steel; and a wooden restrained material 20 that is formed of a pair of wooden restrained plates 21 which are arranged on both wide surfaces of the core material 10, and a pair of wooden side plates 23 which are arranged on both narrow surfaces of the core material 10 and are connected to the pair of restrained plates 21. Each of the paired restrained plates 21 has first bolt holes 22 on both ends in an axial direction. The core material 10 has second bolt holes 13 at positions corresponding to the first bolt holes 22. Connection bolts 30 for end opening prevention of the restrained plates 21 penetrate through the first bolt holes 22 and the second bolt holes 13 to connect the pair of restrained plates 21.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a buckling restrained brace.

  BACKGROUND ART Conventionally, buckling restrained braces for which buckling prevention measures have been taken have been applied as braces for forming a frame of a building (a column / beam frame, a roof frame, etc.). The buckling-restrained braces include a steel core stiffened with steel plate only, a steel core reinforced with RC (Reinforced Concrete reinforced concrete), and a steel core. There are various stiffening forms, such as a form in which steel is covered with steel and mortar.

  By the way, in recent years, the fire resistance and the earthquake resistance of wooden buildings (wooden houses, wooden warehouses, wooden stadiums, etc.) have been improved. Due to the high degree of freedom of layout and design, the healing effect of natural wood, the humidity control effect of wood, and the construction cost of wooden houses, the construction cost of wooden houses is generally higher than that of steel or RC buildings. Although it has the advantage of being inexpensive, the above-mentioned improvement in fire resistance and earthquake resistance is one of the factors that have increased the attention of wooden buildings such as wooden houses. When the above-mentioned conventional buckling-restrained brace is incorporated in the frame of such a wooden house, wooden columns and beams and buckling-restrained braces having metal or concrete stiffeners are mixed. It is undeniable that the appearance becomes unbalanced.

  Therefore, there is a method of covering the entire buckling restrained brace with a wooden or paper panel so that the metal or concrete stiffener cannot be visually recognized from the outside. Since labor is required, construction costs may be increased. In addition, conventional buckling restrained braces tend to be heavy due to heavy use of metal, concrete, mortar, etc., and heavy wooden beams and columns constituting a wooden house have heavy weight. Attaching buckling restrained braces is structurally unbalanced.

  Therefore, a buckling-restrained brace suitable for being incorporated in a frame of a wooden building such as a wooden house has been proposed. Specifically, it is a buckling restrained brace having a core and a pair of restraining members arranged along both surfaces of the core, wherein the core is formed of steel and the pair of restraining members is formed of wood. Then, a laminated material is applied to the restraining material, and the laminated material is a buckling restrained brace in which lamina is laminated in parallel with the core material (for example, see Patent Document 1).

Japanese Patent No. 4901491

  For a buckling-restrained brace in which a steel core is surrounded by wooden restraints, for example, when the frame is deformed during an earthquake and an axial force acts on the core, the core starts to buckle, Can be deformed so that the wooden restraints surrounding it, in particular the ends, are pushed outward and open. When the restraining member is opened outward in this way, the core cannot be restrained so as to prevent buckling, and the core may buckle. Patent Literature 1 does not mention such prevention of opening of the end of the restraining member, and thus it is not clear whether the opening of the end of the restraining member can be suppressed.

  The present invention has been made in view of the above problems, and is suitable for use by being incorporated in a frame of a wooden building, and suppresses the restraint plate from opening outward when the core material tries to buckle. It is intended to provide a buckling-restrained brace that can be used.

In order to achieve the above object, one aspect of the buckling restrained brace according to the present invention includes:
Steel plate-shaped core material,
A pair of wooden restraint plates arranged on both sides of the core with a wide width, and a pair of wooden side plates arranged on both narrow sides of the core and connected to the pair of constraint plates. And a wooden restraining member formed by
Each of the pair of restraining plates has a first bolt hole at both ends in the axial direction, and the core has a second bolt hole at a position corresponding to the first bolt hole,
The first bolt hole and the second bolt hole are penetrated by connecting bolts for preventing the end portions of the restraint plates from opening, thereby connecting the pair of restraint plates.

  According to this aspect, since the core members are connected to each other by the connecting bolts for preventing the ends of the restraining plates from opening at both ends of the pair of restraining plates, the opening of the restraining plate ends is suppressed. The buckling of the core material can be prevented, and a buckling restrained brace having high deformation performance can be obtained. Here, the pair of restraining plates are connected by a pair of side plates, and a wooden restraining member having a closed structure of four face members is formed. Since the steel core material is surrounded by the wooden restraining material, there is no possibility that even when the steel core material is applied to the frame of a wooden building, the appearance may be unbalanced with the frame constituent members.

  The constraining plate and the side plate forming the wooden constraining member and the core material are cut off, and a gap may be present between the constraining plate and the side plate and the core material. Since the wooden restraint and the core are cut off, the axial force, shearing force, and the like acting on the core are suppressed from acting on the wooden restraint. Further, an unbond material such as grease may be provided between the constraint plate and the side plates and the core material. With this unbonded material, the dynamic frictional force between the core material and the wooden restraining material when the core material expands and contracts can be reduced.

  As described above, the connection bolt is a member having an action of preventing the pair of constraint plates from opening, and the pair of constraint plates are connected by the pair of side plates. Further, the wooden restraining member and the side plate may be formed of a solid material, or may be formed of a laminated material in which lamina is laminated.

  Further, since the wooden restraining member has a configuration in which the pair of side plates are connected to the pair of restraining plates, the processing of the wooden restraining material is facilitated. For example, the buckling restrained brace described in Patent Literature 1 is a process in which a laminated wood is processed to produce two restraining members having an L-shaped cross section, and these are turned upside down to be connected with a core material sandwiched therebetween. Cost. On the other hand, in the buckling restrained brace of the present embodiment, a wooden restraining member is manufactured by connecting a pair of side plates to a pair of restraining plates, and for example, a core material is inserted into a hollow of the wooden restraining member. Makes it possible to manufacture a buckling-restrained brace (when the end of the core material does not have a flange and is made of only a web, such a manufacturing is possible). Therefore, the manufacture of the buckling restrained brace is further facilitated.

  Further, another aspect of the buckling restrained brace according to the present invention is characterized in that the side plate is fixed to the restraint plate by a fixing bracket.

  According to this aspect, since the side plate is fixed to the constraint plate by the fixing metal, the manufacture of the wooden constraint member is further facilitated. For example, as compared with the case where the restraint plate and the side plate are fixed with an adhesive, the time required for curing the adhesive can be made unnecessary, so that the manufacturing time may be shorter. Here, examples of the fixing bracket include screws and nails.

  In another aspect of the buckling restrained brace according to the present invention, the second bolt hole is a long hole extending in a longitudinal direction of the core material.

  According to this aspect, since the second bolt hole formed in the core is a long hole extending in the longitudinal direction of the core, for example, the frame is deformed during an earthquake, and the frame is deformed in accordance with the deformation of the frame. When the core material expands and contracts, the connecting bolts that connect the constraint plates that pass through the long holes are not affected by the expansion and contraction of the core material. For this reason, the connecting bolt moves due to the expansion and contraction of the core material, and the axial force acting on the wooden restraining member connected to the connecting bolt due to the movement of the connecting bolt is eliminated. The possibility of damage to the wooden restraint due to the axial force is eliminated.

  In another aspect of the buckling restrained brace according to the present invention, the first bolt hole is larger in diameter than a bolt diameter of the connection bolt.

  According to this aspect, when the frame is deformed during an earthquake, and the core material is deformed in the axial direction due to this deformation, and further displaced in a direction orthogonal to the axial direction, such displacement of the core material is caused. Can be prevented from acting on the pair of restraint plates via the connecting bolt. As described above, the influence of the core material in the axial direction can be eliminated by making the second bolt hole formed in the core material a long hole (loose hole) as described above. The effect of the displacement in the direction perpendicular to the direction can be eliminated by making the first bolt hole formed in the restraint plate larger in diameter than the bolt diameter of the connecting bolt.

In another aspect of the buckling restrained brace according to the present invention, the core has a plate-shaped web,
At each end of the core in the axial direction, each has two flanges orthogonal to the web,
The connection bolt for connecting the pair of restraining plates sandwiching the web is disposed between the two flanges.

  According to this aspect, since the core has the central web and the two flanges on both sides at the ends, the seat is rigidly connected to the gusset plate or the like at the corner of the frame. The rigidity of the end of the core material of the flexure-restrained brace, for example, out of the construction plane, can be increased. In the buckling restrained brace of this aspect, the central general portion is a web made of a flat steel material or the like, and both ends are H-shaped steel materials having flanges attached to both sides of the web. Therefore, the gusset plate attached to the corner of the frame to which the end of the core is connected also has the same H shape as the end of the core.

  In another aspect of the buckling restraint brace according to the present invention, a gap is provided between the flange and the pair of restraint plates.

  According to this aspect, the frame is deformed during an earthquake due to the gap between the pair of flanges at the end of the core material and the (side surface of the end) between the pair of flanges. An external force such as a bending moment applied to the constraint plate from the flange of the core member due to the deformation can be eliminated.

  Another aspect of the buckling restrained brace according to the present invention is characterized in that the specifications of the wooden restraining member and the core material are set so as to satisfy the following expression (A).

本態様によれば、木製拘束材に特有のめり込み耐力と補剛力との関係に基づき、木製拘束材と芯材の各仕様を適切に設定することができる。ここで、「仕様」とは、芯材の幅や板厚、芯材の降伏耐力、木製拘束材の設計用軸力（に堪え得る木製拘束材の断面寸法や断面剛性、ヤング係数（材質）等）が挙げられる。

According to this aspect, it is possible to appropriately set the specifications of the wooden restraining member and the core material based on the relationship between the burling strength and the stiffening force specific to the wooden restraining member. Here, the “specifications” are the width and thickness of the core material, the yield strength of the core material, the axial force for designing the wooden restraint material (the cross-sectional dimensions and cross-sectional rigidity of the wooden restraint material, Young's modulus (material) Etc.).

  Further, another aspect of the buckling restrained brace according to the present invention is characterized in that a pitch at which the side plate is fixed to the restraint plate by the fixing bracket satisfies the following expression (B).

本態様によれば、拘束板と側板の接続部に作用するせん断力以上のせん断耐力を有するようにして、固定金具のピッチ（もしくは固定金具の本数）を適切に設定することができる。

According to this aspect, the pitch of the fixtures (or the number of fixtures) can be appropriately set so as to have a shear strength equal to or greater than the shearing force acting on the joint between the constraint plate and the side plate.

  As can be understood from the above description, the buckling restrained brace of the present invention is suitable for use by being incorporated in the frame of a wooden building, and the restraining plate is used when the core material tries to buckle. Opening to the outside can be suppressed.

It is a perspective view of an example of the core material which forms the buckling restrained brace concerning an embodiment. FIG. 2 is a view taken in the direction of an arrow II in FIG. 1 and showing bolts forming a connection bolt together. It is a perspective view of an example of the wooden restraining material which forms the buckling restrained brace concerning an embodiment. FIG. 4 is a view taken in the direction of an arrow IV in FIG. 3 and showing bolts forming a connection bolt together. It is a perspective view of an example of a buckling restraint brace concerning an embodiment. FIG. 6 is a view taken along the line VI-VI in FIG. 5. FIG. 7 is a view taken along the line VII-VII in FIG. 5. It is a figure showing the state where the buckling restrained brace concerning an embodiment was built into the frame of the wooden building. It is a figure showing the whole seat bending line of a buckling restrained brace.

  Hereinafter, a buckling restrained brace according to an embodiment will be described with reference to the accompanying drawings.

[Buckling restrained brace according to embodiment]
<Core material>
First, an example of a core material forming the buckling restrained brace according to the embodiment will be described with reference to FIGS. 1 and 2. Here, FIG. 1 is a perspective view of an example of a core material forming the buckling restrained brace according to the embodiment, and FIG. 2 is a view taken in the direction of an arrow II in FIG. FIG.

  The core material 10 is formed of an elongated flat steel plate. The central general portion 11 and both end portions 12 are continuous, and the width of the end portion is relatively large with respect to the width of the general portion 11. There is a shape in which the width gradually increases from the general portion 11 to the end portion 12.

  From the general portion 11 to the end portion 12, the entire core material 10 is a web made of a flat steel plate. At the end portion 12, a pair of flanges 14 orthogonal to the web are connected to both sides by welding to form a cross section. Has an H-shape.

  The core material 10 is preferably formed 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). Good absorbency.

  As shown in FIG. 2, an elongated hole 13 (an example of a second bolt hole) extending in the longitudinal direction which is the axial direction L of the core 10 is formed in the end portion 12. The width of the long hole 13 is set to a width substantially equal to the diameter φ1 of the bolt 31 shown by a two-dot chain line in FIG. Further, when the buckling restrained brace is incorporated in the frame and the core material 31 expands and contracts in the axial direction due to the horizontal force at the time of the earthquake, the length t1 of the elongated hole 13 is determined by the expansion and contraction of the core material 10. Is set to a length that does not interfere with

  Since the core member 10 has the flanges 14 on both sides of the end portion 12 (web), the buckling-restrained brace is incorporated into the frame, and can act on the core member 10 when subjected to, for example, a horizontal force during an earthquake. Rigidity against out-of-plane bending moments can be increased.

<Wood restraint>
Next, an example of a wooden restraining member forming the buckling restrained brace according to the embodiment will be described with reference to FIGS. 3 and 4. Here, FIG. 3 is a perspective view of an example of a wooden restraining member forming the buckling restraining brace according to the embodiment, and FIG. 4 is a view in the direction of arrow IV in FIG. It is the figure which showed the bolt together.

  The wooden restraining member 20 has a pair of restraining plates 21 and a pair of side plates 23 connecting the pair of restraining plates 21, and the core 10 is disposed in a gap between the pair of restraining plates 21. ing. The side plate 23 is fixed to the restraining plate 21 at a predetermined pitch t2 by fixing fittings 24 such as screws and nails. The method for setting the pitch t2 will be described in detail below. As described above, by fixing the pair of side plates 23 to the pair of constraint plates 21 with the fixing fittings 24, it is possible to easily manufacture the wooden constraint member 20 having a closed structure with four face members.

  The restraint plate 21 and the side plate 23 may be formed of either a solid material or a wood material including a laminated material laminated with lamina. As described in detail below, the cross-sectional area, the cross-sectional rigidity, the Young's modulus, and the like of the wooden restraining member 20 are set so as to prevent the entire buckling of the buckling restrained brace. The Young's modulus is determined by the material of the wood. Examples of the wood material include Japanese red pine, larch, fir, spruce and the like.

  As shown in FIG. 3, the restraint plate 21 protrudes from an end of the side plate 23, and a first bolt hole 22 is formed in a region where the restraint plate 21 protrudes. When the wooden restraining member 20 is attached to the periphery of the core member 10, the second bolt hole 13 of the core member 10 and the first bolt hole 22 of the restraining plate 21 are aligned with each other. Bolts 31 are inserted into the upper and lower first bolt holes 22 (see FIGS. 2 and 4).

  As shown in FIG. 4, the first bolt hole 22 formed in the restraint plate 21 has a diameter φ2 larger than the diameter φ1 of the bolt 31 to be inserted. Since the first bolt hole 22 formed in the restraining plate 21 is set to have a larger diameter than the bolt 31, the frame in which the buckling restrained brace is incorporated is deformed during an earthquake, and the core material is deformed due to the deformation. Eliminates such displacement of the core material 10 acting on the pair of restraint plates 21 via the bolts 31 when the 10 is deformed in the axial direction L and further displaced in the direction orthogonal to the axial direction L. it can.

  Although the wooden restraining member in the illustrated example has a form in which the side plate is fixed to the restraining plate with a fixing metal such as a screw, the restraining plate and the side plate may be fixed with an adhesive or the like.

<Buckling restrained brace>
Next, an example of the buckling restrained brace according to the embodiment, which is formed by the core member 10 and the wooden restraining member 20 described above, will be described with reference to FIGS. Here, FIG. 5 is a perspective view of an example of the buckling restrained brace according to the embodiment, FIG. 6 is a view taken along the line VI-VI of FIG. 5, and FIG. 7 is a view taken along the line VII-VII of FIG. FIG.

  In the buckling restrained brace 50, a wooden restraining material 20 is disposed so as to surround the general portion 11 of the core material 10, and the end of the restraining plate 21 extends between the two flanges 14 at the end of the core material 10. ing. A pair of restraining plates 21 are provided on both wide surfaces of the core material 10, and a pair of side plates 23 are provided on both narrow surfaces of the core material 10. Then, the bolt 31 is inserted into the aligned center second bolt hole 13 and upper and lower two first bolt holes 22, and is tightened by the nut 32, thereby forming the bolt 31 and the nut 32. The connecting bolt 30 prevents the ends of the pair of restraint plates 21 from opening. That is, the closed structure formed by the four face members of the pair of restraint plates 21 and the pair of side plates 23 is formed by the plurality of fixing brackets 24, and the connection bolt 30 serves as a means for preventing the end portions of the pair of restraint plates 21 from opening. A washer 33 is provided on the surface of the first bolt hole 22 of the restraining plate 21, and the bolt 31 is tightened with a nut 32 via the washer 33.

  When the pair of restraining plates 21 forming the buckling restraining brace 50 are connected by the connecting bolts 30 for preventing the ends from opening, the core 10 starts to buckle and the ends of the restraining plates 21 are pushed outward. Opening deformation is suppressed. Therefore, the overall buckling of the buckling restrained brace 50 is suppressed, and the compressive strength of the buckling restrained brace 50 is improved, so that the frame in which the buckling restrained brace 50 is incorporated and a wooden building including this frame are provided. Excellent seismic reinforcement effect can be provided.

  As shown in FIG. 7, a gap 15 having a predetermined width t3 is provided between the flange 14 at the end of the core member 10 and a pair of restraining plates 21 disposed between the two flanges 14. ing. Since the gap 15 is interposed between the flange 14 and the restraining plate 21 in this manner, the frame in which the buckling restrained brace 50 is incorporated is deformed during an earthquake, and the deformation from the flange 14 of the core 10 is caused by the deformation. The application of an external force such as a bending moment to the constraint plate 21 can be eliminated.

  As described above, in the buckling restrained brace 50, the core 10 has the elongated hole 14 in the axial direction, the restraining plate 21 has the first bolt hole 22 having a larger diameter than the bolt 31, Has a gap 15 between the flange 14 and the restraint plate 21. With these configurations, when the frame is deformed during an earthquake, an external force such as an axial force or a bending moment acts on the wooden restraining member 20 from the core member 10 via the connecting bolt 30, and the wooden restraining member 20 is caused by the external force. Damage is eliminated. That is, since the pair of restraining plates 21 are connected to each other by the connecting bolts 30 for preventing the ends from being opened, the wooden restraining material 20 is damaged due to an external force being input from the connecting bolt 30 to the wooden restraining material 20. The danger of the occurrence can be eliminated by the various configurations described above.

  6 and 7 show a state in which there is no gap between the wooden restraining material 20 and the general portion 11 of the core material 10, but the wooden restraining material 20 and the core material 10 are cut off from each other. . In addition, some gap may exist between the wooden restraining member 20 and the core member 10. Further, an unbond material such as grease may be provided at the interface between the wooden restraining member 20 and the core member 10 regardless of the presence or absence of the gap between the wooden restraining member 20 and the core member 10.

  Further, the core material constituting the buckling restrained brace in the illustrated example is a form having two flanges at its ends, but may be a buckling restrained brace provided with a core material having no flange. In this case, the gusset plate to which the core is attached is a gusset plate made of a general steel plate other than the H-shaped steel material.

<Example of application of buckling-restrained brace to frame>
Next, an example of application of the buckling restrained brace to a frame will be described with reference to FIG. FIG. 8 is a diagram illustrating a state in which the buckling restrained brace according to the embodiment is incorporated in a frame of a wooden building. In addition, the buckling restrained brace in the illustrated example is incorporated into the frame of an S (S: Steel) building, the frame of an RC building, and the frame of an SRC (SRC: Steel Reinforced Concrete) building in addition to the frame of a wooden building. It may be.

  The frame S shown in FIG. 8 is formed by wooden columns C and beams B constituting a wooden building. H-shaped gusset plates G are attached to two diagonal corners. Both flanges of the core material 10 of the buckling restrained brace 50 are brought into contact with both flanges of the H-shaped gusset plate G, and attachment plates P are provided on both surfaces of both webs. By fixing, the buckling restrained brace 50 is rigidly attached to the frame S.

  When a horizontal force Q acts on the frame S during an earthquake, the frame S is deformed from the illustrated rectangular frame state to a parallelogram state. When the frame S is deformed in this manner, an axial force acts on the core 10 directly connected to the gusset plate G, and the core 10 extends in the axial direction (δ1). Furthermore, the core material 10 can also be displaced in a direction orthogonal to the axial direction (δ2).

  As described above, the buckling restrained brace 50 is configured such that the core 10 has the elongated hole 14 in the axial direction, and the restraining plate 21 has the first bolt hole 22 having a larger diameter than the bolt 31. Thus, even when the core material 10 is deformed or displaced, the application of external force such as axial force from the core material 10 to the wooden restraining material 20 via the connection bolt 30 is eliminated. Further, the presence of the gap 15 between the flange 14 of the core member 10 and the constraint plate 21 eliminates the application of an external force such as a bending moment from the flange 14 to the end of the constraint plate 21. Therefore, the wooden restraining member 20 can maintain its original shape without buckling or the like, and can exhibit the buckling restraining function of the core member 10.

<Examination of overall buckling>
Next, a design method for preventing the entire buckling of the buckling restrained brace will be described.

  In the design of the buckling-restrained brace, the following formula (1) is satisfied so that the entire buckling-restrained brace is designed not to buckle.

  Here, the bending moment acting on the center of the constraint plate can be expressed by the following equation (2).

  The condition for preventing the overall buckling of the wooden restraint satisfies the following expression (3).

  Equation (3) is shown in FIG. 9 as the overall seat bending line of the buckling restrained brace. In FIG. 9, the upper side of the entire seat bending line is a safety zone, and the lower side is a danger zone, and the design axial force, the Euler load, and the length of the general portion of the core are set so as to enter the safety zone. , And the yield strength of the wooden restraint is set.

  In addition to checking the relationship between the yielding bending strength of the wooden restraint and the bending moment acting thereon, the allowable bending strength of the wooden restraint in the short term becomes larger than the bending moment acting at the time of core yielding. It is advisable to check this together (mathematical expressions are omitted).

<Examination of burial destruction of wooden restraint>
Next, a description will be given of a method of examining the burial destruction of the wooden restraining member. In order to prevent the wooden restraining material from being broken by the core material sinking into the wooden restraining material, it is verified that the following expression (4) is satisfied.

  In addition to checking the relationship between the indentation strength of the restraining plate and the stiffening force acting thereon, in addition to the fact that the allowable indentation strength of the restraining plate in the short term becomes larger than the stiffening force acting at the time of core material yielding. It is better to check (numerical formula is omitted).

<Examination of the pitch of the fixture that connects the side plate to the restraint plate>
Next, a method of setting the pitch of the fixture for connecting the side plate to the constraint plate will be described. First, it is verified that the following expression (5) is satisfied in order to prevent the shear failure at the joint between the restraint plate and the side plate.

  In order to satisfy the above equation (5), the pitch of the fixture can be set by the following equation (6).

  It should be noted that other embodiments in which other components are combined with the configuration and the like described in the above embodiment may be adopted, and the present invention is not limited to the configuration shown here. This can be changed without departing from the spirit of the present invention, and can be appropriately determined according to the application form.

10: core material, 11: general part (web), 12: end part (web), 13: second bolt hole (long hole), 14: flange, 15: gap, 20: wooden restraint, 21: restraint plate , 22: first bolt hole, 23: side plate, 24: fixing bracket (screw), 30: connecting bolt, 31: bolt, 32: nut, 33: washer, 50: buckling restrained brace, S: frame, C: Pillar, B: Beam, G: Gusset plate, P: Sink plate, F: Bolt

Claims (8)

Steel plate-shaped core material,
A pair of wooden restraint plates arranged on both sides of the core with a wide width, and a pair of wooden side plates arranged on both narrow sides of the core and connected to the pair of constraint plates. And a wooden restraining member formed by
Each of the pair of restraining plates has a first bolt hole at both ends in the axial direction, and the core has a second bolt hole at a position corresponding to the first bolt hole,
A buckling restrained brace, wherein a connecting bolt for preventing an end of the restraint plate from opening passes through the first bolt hole and the second bolt hole to connect the pair of restraining plates. .   The buckling restrained brace according to claim 1, wherein the side plate is fixed to the restraining plate with a fixing bracket.   The buckling restrained brace according to claim 1, wherein the second bolt hole is a long hole extending in a longitudinal direction of the core material.   The buckling restrained brace according to any one of claims 1 to 3, wherein the first bolt hole has a larger diameter than a bolt diameter of the connection bolt. The core has a plate-shaped web,
At each end of the core in the axial direction, each has two flanges orthogonal to the web,
The buckling according to any one of claims 1 to 4, wherein the connecting bolts that connect the pair of restraining plates that sandwich the web are disposed between the two flanges. Restrained braces.   The buckling restrained brace according to claim 5, wherein a gap is provided between the flange and the pair of restraining plates. The buckling restrained brace according to any one of claims 1 to 6, wherein the specifications of the wooden restraining material and the core material are set so as to satisfy the following expression (A).

The pitch for fixing the side plate to the restraint plate with the fixing bracket is set so as to satisfy the following equation (B). A buckling-restrained brace according to any one of the preceding claims.

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