Buckling-restrained brace, installation method of buckling-restrained brace, seismic control structure equipped with buckling-restrained brace

Abstract

To easily construct a buckling restrained brace in which a core material is restrained by a wooden restraining material. [Solution] The brace 20 attached to the beam-column structure is configured as a buckling-restrained brace, comprising a flat steel core member 70 and multiple wooden restraint members 72 sandwiching the core member 70. The multiple wooden restraint members 72 are joined to each other with screws 74 or nails. One end of the brace 20 is attached to the beam-column structure via a seismic damper. The core member may have a cross-shaped or circular cross section.

Description

[Technical Field]

[0001] The present invention relates to a buckling-restrained brace, a method for installing a buckling-restrained brace, and a seismic control structure equipped with a buckling-restrained brace. [Background technology]

[0002] Braces, which are installed to increase the earthquake resistance of buildings, have a long and slender shape and are prone to buckling when subjected to compressive axial force. For this reason, a conventional technique has been known in which the core material that makes up the brace is sandwiched between restraining materials to integrate the core material and prevent buckling by restraining the core material.

[0003] For example, Patent Documents 1 and 2 disclose buckling-restrained braces that use wooden members as restraining materials, from the viewpoint of design when used in wooden buildings and promoting the use of wood. In the buckling-restrained braces disclosed in these documents, a steel core material is sandwiched between a pair of wooden restraining materials, and the core material is restrained by connecting the pair of wooden restraining materials with bolts. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6745371 [Patent Document 2] Patent No. 7008783 Summary of the Invention [Problem to be solved by the invention]

[0005] In a configuration in which wooden restraint members are connected with bolts, as in the buckling restraint braces disclosed in Patent Documents 1 and 2, holes must be drilled in the wooden restraint members to insert the bolts. Furthermore, when inserting the bolts into the wooden restraint members, the holes in the wooden restraint members must be aligned. Thus, a configuration in which wooden restraint members are connected with bolts has the problem of being time-consuming to install. Patent Document 2 also describes that draft pins can be used instead of bolts, but using draft pins also presents similar problems.

[0006] The present invention has been made in consideration of the above points, and aims to make it possible to easily install a buckling restrained brace in which a core material is restrained by a wood restraining material. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention provides a buckling restraint brace that is attached to a column-beam frame, and includes a core material, multiple wood restraint materials arranged to sandwich the core material, and screws or nails that connect the multiple wood restraint materials to each other, with one end of the buckling restraint brace connected to the column-beam frame via a seismic damper.

[0008] According to the present invention, one end of the buckling-restrained brace is attached to the column-beam frame via a seismic damper. Therefore, when a horizontal force acts on the column-beam frame, the force is transmitted to the buckling-restrained brace via the seismic damper. The force is absorbed by the seismic damper, reducing the force transmitted to the buckling-restrained brace, thereby reducing the compressive axial force acting on the buckling-restrained brace. This prevents buckling of the core material, even when the wood restraining members that restrain the core material that makes up the buckling-restrained brace are connected with simple mechanisms such as screws or nails.

[0009] In the present invention, one end of the buckling restraint brace may be connected to the column-beam frame via the seismic damper, and the other end may be fixed to the column-beam frame. In the present invention, the core material may be a strip-shaped flat steel plate, and the wood restraining material may be arranged to sandwich the core material from both sides.

[0010] The seismic damper may be a hysteretic damper, and the hysteretic damper may be a friction damper or a steel damper.

[0011] The present invention also provides a method for installing a buckling restraint brace on a column-beam frame, in which the buckling restraint brace is constructed by sandwiching a core material between multiple wooden restraint materials and connecting the multiple wooden restraint materials to each other with screws or nails, and the buckling restraint brace is installed so that one end of the buckling restraint brace is connected to the column-beam frame via a seismic damper.

[0012] The present invention also provides a seismic control structure for a column-beam frame, comprising: a buckling restraint brace attached to the column-beam frame; and a seismic control damper interposed between one end of the buckling restraint brace and the column-beam frame and connecting the buckling restraint brace to the column-beam frame, wherein the buckling restraint brace comprises a core material, a plurality of wooden restraint materials arranged to sandwich the core material, and screws or nails that connect the plurality of wooden restraint materials to each other.

[0013] In this case, the seismic damper may be a friction damper comprising a first member and a second member that generates a friction force by sliding relative to the first member, and the first member may be attached to an upper beam or a lower beam or floor slab in the column-beam structure, and a pair of the buckling restraint braces may each have one end attached to the second member of the friction damper, extend in a V-shape or an inverted V-shape, and have the other end connected to the column-beam structure. [Effects of the Invention]

[0014] According to the present invention, a buckling restrained brace in which a core material is restrained by a wood restraining material can be easily constructed. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a front view showing a column-beam frame vibration control structure according to one embodiment of the present invention. [Figure 2] 2 is a cross-sectional view taken along line II-II in FIG. 1, showing details of the seismic damper. FIG. [Figure 3] 1 is a cross-sectional view of a brace according to this embodiment cut along a plane perpendicular to the longitudinal direction. FIG. [Figure 4] FIG. 2 is a plan view of a brace according to the present embodiment. [Figure 5] FIG. 10 is a diagram for explaining the axial force acting on the brace when the maximum static friction force occurs in the friction damper. [Figure 6] FIG. 10 is a model diagram showing a state in which a stiffening force acts on a brace. [Figure 7] FIG. 10 is a cross-sectional view of a brace according to a second embodiment, taken along a plane perpendicular to the longitudinal direction. [Figure 8] FIG. 10 is a cross-sectional view of a brace according to a third embodiment, taken along a plane perpendicular to the longitudinal direction. DETAILED DESCRIPTION OF THE INVENTION

[0016] Figure 1 is a front view showing a seismic control structure 10 of a column-beam frame 1, which is one embodiment of the present invention. As shown in the figure, the seismic control structure 10 is installed within a frame plane surrounded by upper beam 1A, lower beam 1B, and left and right columns 1C, 1D of the column-beam frame 1. When the seismic control structure 10 is installed on the first floor of a building, the lower beam 1B may serve as a floor slab.

[0017] The vibration control structure 10 includes a brace 20 and a friction damper 30. The friction damper 30 is attached to the upper beam 1A. A pair of braces 20 is provided, and the upper ends of each are connected to the friction damper 30. The pair of braces 20 extend diagonally downward from the friction damper 30 in an inverted V shape, and the lower ends are fixed to the inner surface of the beam-column frame 1 via steel members 2. That is, the upper end of the brace 20 is connected to the upper beam 1A of the column-beam frame 1, and the lower end is fixed to the column-beam frame 1.

[0018] 2 is a cross-sectional view of the friction damper 30 taken along line II-II in FIG. 1. As shown in FIG. 2, the friction damper 30 includes a pair of first members 32, 34 and a second member 36. The first members 32, 34 and the second member 36 are plate-shaped members, and the upper part of the second member 36 is sandwiched between the lower parts of the first members 32, 34.

[0019] The upper ends of the first members 32, 34 are bent at right angles in opposite directions to form mounting portions 33, 35. The mounting portions 33, 35 are in contact with the underside of the upper beam 1A, and the mounting portions 33, 35 are fixed to the underside of the upper beam 1A with bolts 39, thereby attaching the friction damper 30 to the upper beam 1A.

[0020] The first member 32 and the second member 36 on one side have sliding plates 38 and 40 on their opposing surfaces, respectively. The first member 34 and the second member 36 on the other side have sliding plates 42 and 44 on their opposing surfaces, respectively. The sliding plates 38, 40, 42, and 44 are made of, for example, stainless steel.

[0021] Friction plates 46, 48 are sandwiched between the opposing slide plates 38, 40, and between the opposing slide plates 42, 44. The friction plates 46, 48 may be made of any material that generates friction between them and the slide plates 38, 40, 42, 44, and may be made of, for example, a known resin-based friction material.

[0022] The first member 32, friction plate 46, second member 36, friction plate 48, and first member 34 described above are fastened together from both the left and right sides in Fig. 2 by fasteners 64. The fasteners 64 will be described in detail below.

[0023] 2, the fastener 64 includes a high-tensile bolt 50, a nut 52, a washer 54, a disc spring stack 56, a bushing 58, and a washer 60. The disc spring stack 56 is made up of a plurality of disc springs stacked one on top of the other.

[0024] The first member 32, the friction plate 46, the second member 36, the friction plate 48, and the first member 34 are provided with insertion holes 32a, 46a, 36a, 48a, and 34a, respectively. The friction plate 46, the second member 36, the friction plate 48, and the first member 34 are aligned so that the insertion holes 32a, 46a, 36a, 48a, and 34a are coaxial, and a high-tension bolt 50 is inserted through these insertion holes. As will be described later, the second member 36 is displaced in the horizontal direction (the depth direction of the paper in FIG. 2 ) relative to the first members 32 and 34, so the insertion hole 36a of the second member 36 is formed larger than the other insertion holes to provide play between the second member 36 and the high-tension bolt 50.

[0025] The high-tension bolt 50 is inserted into the insertion hole from the left side in FIG. 2 , with its tip protruding from the bushing 58. The disc spring stack 56 is interposed between the head of the bushing 58 and a washer 60 arranged on the surface of the first member 32. A nut 52 is fastened to the portion of the high-tension bolt 50 protruding from the bushing 58, causing the bushing 58 to compress the disc spring stack 56. As a result, the first member 32, friction plate 48, second member 36, friction plate 48, and first member 34 are fastened together by the elastic force of the disc spring stack 56. The disc spring stack 56 has the property of generating a generally constant elastic force regardless of the degree to which the nut 52 is fastened.

[0026] In this way, in the friction damper 30, the sliding plates 38, 42 of the first members 32, 34 and the sliding plates 40, 44 of the second member 36 are fastened by the fasteners 64 on both sides of the friction plates 46, 48. Therefore, when the first members 32, 34 and the second member 36 attempt to move relative to each other in the depth direction of the paper in FIG. 2 (the left-right direction in FIG. 1), a friction force is generated between them. As described above, the disc spring stack 56 generates a substantially constant elastic force, so the first members 32, 34, the friction plates 46, 48, and the second member 36 are also fastened with a substantially constant force. Therefore, the maximum static friction force and kinetic friction force generated between the first members 32, 34 and the second member 36 via the friction plates 46, 48 are each substantially constant.

[0027] During an earthquake, seismic motion acts on the beam-column frame 1. For example, suppose a horizontal force acts to the right in FIG. 1 on the upper beam 1A of the beam-column frame 1. In this case, because the first members 32 and 34 of the friction damper 30 are attached to the upper beam 1A, the horizontal force acting on the upper beam 1A is transmitted directly to the first members 32 and 34. Meanwhile, because the upper end of the brace 20 is attached to the second member 36 of the friction damper 30 and the lower end of the brace 20 is fixed to the beam-column frame 1, the brace 20 resists the horizontal movement of the second member 36. Therefore, when the first members 32 and 34 attempt to displace to the right due to the transmission of the rightward horizontal force, a horizontal friction force is generated between the first members 32 and 34 and the second member 36 via the friction plates 46 and 48.

[0028] In this way, the friction damper 30 generates a friction force between the first members 32, 34 and the second member 36. The friction damper 30 has the function of absorbing vibration energy caused by seismic motion using this friction force, thereby controlling the vibration of the beam-column frame 1. Note that Fig. 2 shows an example of the friction damper 30, and the configuration of the friction damper 30 is not limited to this, and any configuration is sufficient as long as it can absorb vibration energy using friction force generated by the relative displacement of two members.

[0029] When the horizontal force acting on the upper beam 1A is equal to or less than the maximum static friction force Q between the first members 32, 34 and the second member 36, the first members 32, 34 and the second member 36 do not slip, and no relative horizontal displacement occurs. Therefore, the rightward horizontal force transmitted to the first members 32, 34 is transmitted from the second member 36 to the beam-column frame 1 via the brace 20. In this case, the horizontal displacement of the upper beam 1A is restricted by the brace 20, and an axial force (a compressive axial force acts on the brace 20 on the right side in the figure, and a tensile axial force acts on the brace 20 on the left side) corresponding to the friction force between the first members 32, 34 and the second member 36 (see Figure 4, described later).

[0030] When the horizontal force acting on the upper beam 1A exceeds the maximum static friction force Q, the first members 32, 34 and the second member 36 begin to slide relative to each other in the horizontal direction via the friction plates 46, 48, causing relative horizontal displacement. At this time, the friction force between the first members 32, 34 and the second member 36 becomes a kinetic friction force Q' (< the maximum static friction force Q).

[0031] The reaction force against the friction force between the first members 32, 34 and the second member 36 of the friction damper 30 is transmitted from the second member 36 to the beam-column frame 1 via the brace 20. In other words, an axial force corresponding to the kinetic friction force Q' between the first members 32, 34 and the second member 36 acts on the brace 20. The maximum value of the friction force between the first members 32, 34 and the second member 36 is the maximum static friction force Q, so the axial force acting on the brace 20 is maximum when the friction force is the maximum static friction force Q.

[0032] Note that the above has been explained regarding the case where a horizontal force acting to the right in Figure 1 acts on the upper beam 1A. However, when a horizontal force acting to the left acts, the situation is the same except that the compressive and tensile axial forces acting on the left and right braces 20 are reversed.

[0033] As described above, when a horizontal force acts on the upper beam 1A during an earthquake, a compressive axial force acts on one of the braces 20, and the magnitude of this compressive axial force reaches a maximum just before the horizontal force reaches the maximum static friction force Q and the first members 32, 34 and the second member 36 begin to slide. If the maximum value of this compressive axial force exceeds the buckling load of the brace 20, buckling will occur in the brace 20. To prevent such buckling, in this embodiment, the brace 20 is a buckling-restrained brace equipped with a restraining material to prevent buckling.

[0034] FIG. 3 is a cross-sectional view of the brace 20 cut along a plane perpendicular to the longitudinal direction, and FIG. 4 is a plan view of the brace 20. As shown in Figures 3 and 4, the brace 20 comprises a core material 70, which is a long, thin, strip-shaped flat steel plate (flat bar), a pair of wooden restraint materials 72 arranged to sandwich the core material 70 from both sides, screws 74 that connect the pair of wooden restraint materials 72 to each other, and spacer materials 76 that fill the gaps on both sides of the core material 70 between the pair of wooden restraint materials 72. The screws 74 are threaded into the core material 70 at positions on both sides thereof, passing from the surface of one of the wooden restraint materials 72 through the spacer material 76 and reaching the interior of the other wooden restraint material 72 .

[0035] While Fig. 3 shows the left and right screws 74 arranged in up-down opposite directions on the same cross section, as shown in Fig. 4, multiple screws 74 may be arranged on each side of the core material 70 at intervals along the length of the brace 20. In the example of Fig. 4, the screws 74 on both sides are arranged alternately in a staggered pattern to connect the wood restraint materials 72 with as uniform a force as possible along the length of the brace 20, and the direction in which the screws 74 are inserted is alternately reversed along the length.

[0036] As will be discussed below, the constituent material of the wooden restraint member 72 is not particularly limited as long as it is a wooden material strong enough to restrain the buckling of the core material 70, but for example, laminated wood with little variation in strength is used. The spacer member 76 is also made of, for example, a wooden material, but it may be the same wooden material as the wooden restraint member 72 or a different wooden material, and may also be made of any material that allows the screws 74 to pass through, such as resin.

[0037] Both longitudinal ends of the core material 70 protrude from the wooden restraint material 72. As shown in Figures 1 and 2, the upper end 70a protruding from the wooden restraint material 72 is fixed to the second member 36 of the friction damper 30 via a connecting fitting 80, and the lower end 70b is fixed to a steel material 2 fixed to the inside of the structural surface of the beam-column structure 1.

[0038] As described above, according to this embodiment, the core material 70 of the brace 20 is sandwiched between a pair of wooden restraint materials 72 on both sides, and these wooden restraint materials 72 are connected with screws 74, thereby preventing buckling when a compressive axial force is applied to the brace 20.

[0039] Furthermore, the wooden restraint materials 72 can be joined together by directly screwing the screws 74 into the wooden restraint materials 72. This eliminates the need to pre-drill pilot holes or align the pilot holes as is required when joining with bolts, making the joining of the wooden restraint materials 72 simple and effortless.

[0040] Incidentally, the fastening force of the wooden restraint material 72 using the screws 74 is weaker than when fastened using the bolts described in the prior art. However, we will explain below how buckling of the core material 70 can be prevented even when the wooden restraint material 72 is fastened using the screws 74.

[0041] As described above, when an earthquake occurs, a horizontal force acts on the friction damper 30, and an axial force corresponding to the magnitude of this horizontal force acts on the brace 20. This axial force reaches its maximum when the horizontal force acting on the upper beam 1A, i.e., the friction force generated in the friction damper 30, reaches the maximum static friction force Q.

[0042] FIG. 5 is a diagram for explaining the axial force acting on the brace 20 when the maximum static friction force Q is generated in the friction damper 30. As shown in the figure, when the maximum static friction force Q acts in the right direction in the figure, an axial compressive force acts on the right brace 20 and an axial tensile force acts on the left brace 20, and due to the balance of forces, the magnitudes of these compressive axial force and tensile axial force are equal. If the installation angle of the brace 20 (angle with respect to the horizontal direction) is θ, the axial force Nc acting on the brace 20 is Nc=(Q / 2) / cosθ As shown in Figure 5, for example, if the span between columns is 6000 mm and the height between the upper and lower beams is 4150 mm, then cosθ = 0.586.

[0043] The stiffening force Fp (the force that restrains the expansion due to buckling) required to prevent the brace 20 from buckling can be determined through experiments and analysis, but empirically, it is possible to prevent buckling by restraining it with a force of approximately 2% of the axial force.

[0044] Therefore, if the maximum static friction force Q generated in the friction damper 30 is, for example, 800 kN, the required stiffening force Fp is Fp=(800kN / 2) / 0.586*2%=14kN This becomes:

[0045] Regarding screw 74, for example, according to the strength data on the technical data sheet for Synegic Co., Ltd.'s Spring Lead S (https: / / synegic.satori.site / ps-tds), the pull-out strength of part number PS10 is approximately 12 kN, so if two of these screws are used, the total pull-out strength will exceed the required stiffening force of 14 kN, preventing buckling.

[0046] In the above explanation, the ratio of the required stiffening force to the axial force of 2% and the maximum static friction force Q of the friction damper 30 of 800 kN are values ​​that have a certain degree of validity, but they are merely hypothetical values, and it is possible that the actual required stiffening force Fp will be greater than the value considered above. However, as shown in Figure 4, by providing multiple screws 74 along the longitudinal direction of the brace 20, it is possible to obtain a stiffening force sufficient to prevent buckling with a margin of error.

[0047] On the other hand, in a comparative example, if one end of the brace 20 is not attached to the beam-column frame 1 via the friction damper 30, but both ends are attached directly to the beam-column frame 1, the horizontal force acting on the upper beam 1A is transmitted directly to the brace 20. For this reason, the axial force acting on the brace 20 is much greater (several tens to a hundred times greater) than when the maximum static friction force Q of the friction damper 30 acts, as in this embodiment. Therefore, in the comparative example, if the wooden restraint material 72 is attached with screws, the required stiffening force cannot be obtained, so it is necessary to attach it firmly with bolts or the like.

[0048] In this way, in this embodiment, rather than attaching both ends of the brace 20 directly to the column-beam frame 1, one end is attached to the column-beam frame 1 via a friction damper 30, which significantly reduces the axial force acting on the brace 20. This makes it possible to connect the wooden restraint material 72 using the simple method of simply screwing in the screws 74, while preventing the brace 20 from buckling.

[0049] When the buckling of the brace 20 is restrained by the wooden restraining members 72, a bending force acts on the wooden restraining members 72 due to the force acting from the core material 70. Therefore, the strength required for the wooden restraining members 72 to prevent buckling is considered as follows.

[0050] As shown in Figure 6, the length L of the wooden restraint member 72 (i.e., the length of the buckling restraint portion of the brace 20) is set to 3100 mm (3.1 m), and the brace 20 is assumed to be a beam supported at both ends with a maximum stiffening force Fp = 14 kN acting on the center, which is borne by the wooden restraint member 72 on one side. In this case, the maximum bending moment Md acting on the wooden restraint member 72 is Md=Fp·L / 4=14kN*3.1m / 4=11kNm This becomes:

[0051] Furthermore, if the width B of the wooden restraint material 72 is 360 mm and the thickness D is 120 mm, the section modulus Z is Z=B·D 2 / 6=360mm*(120mm) 2 / 6=864000mm 3 This becomes:

[0052] Therefore, the maximum bending stress σd of the wooden restraint material 72 is σd=Md / Z=11000N*1000mm / 864000mm 3 =13N / mm 2 This becomes:

[0053] When laminated wood is used as the wooden restraint material 72, the tensile strength Fb varies depending on the strength grade, but is in the range of 20 to 50 N / mm 2 The short-term allowable bending stress is the tensile strength Fb multiplied by 2 / 3. Therefore, for example, if Fb is 30 N / mm 2 If laminated timber with a strength grade of 20N / mm is used, the short-term allowable bending stress is 20N / mm 2 >σd(13N / mm 2 ) and the wood restraining member 72 has the strength necessary to restrain the core material 70 from buckling.

[0054] In the above study, hypothetical values ​​were used for the cross-sectional dimensions of the wooden restraint material 72. However, in actual design, the material and dimensions of the wooden restraint material 72 should be determined using the above calculation method so that the short-term allowable bending stress exceeds the stiffening force Fp.

[0055] As explained above, in this embodiment, by connecting the brace 20, which is a buckling-restrained brace, to the column-beam structure 1 via the friction damper 30, the axial force acting on the brace 20 is kept below a value corresponding to the maximum static friction force generated by the friction damper 30. This makes it possible to prevent buckling of the brace 20 with an easily installable structure in which the wooden restraint material 72 is connected with the screws 74.

[0056] In the present invention, hysteretic dampers other than friction dampers 30 (for example, steel dampers) may be used, and seismic dampers other than hysteretic dampers, such as oil dampers or viscous dampers, may also be used. Even when a seismic damper other than friction damper 30 is used, the horizontal force acting on the beam-column frame 1 is absorbed by the seismic damper, thereby significantly reducing the axial force acting on brace 20. Therefore, just as in the case of using friction dampers 30, buckling can be prevented even with braces 20 configured such that wooden restraint members 72 are connected with screws 74.

[0057] Furthermore, in this embodiment, the friction damper 30 is attached to the upper beam 1A, and the brace 20 extends downward from the friction damper 30 in an inverted V-shape and is attached to the column-beam frame 1, but this is not limited to this. The friction damper 30 may be attached to the lower beam 1B (or floor slab), and the brace 20 may extend upward from the friction damper 30 in a V-shape and have its upper end attached to the column-beam frame 1.

[0058] Next, another embodiment of the present invention will be described. In the embodiment described below, only the configuration of the brace differs from the above embodiment, so only the brace will be described.

[0059] 7 is a cross-sectional view of a brace 120 according to a second embodiment of the present invention, taken along a plane perpendicular to the longitudinal direction. As shown in the figure, the brace 120 of this embodiment includes a steel core member 170 with a cross-shaped cross section, four wooden restraint members 172, screws 174, and spacer members 176.

[0060] The wood constraint members 172 have a rectangular cross-section and are arranged on the top, bottom, left, and right sides of the core material 170, sandwiching each web 170a of the core material 170. Spacer members 176 are provided in the gaps between the wood constraint members 172 on the outside of each web 170a. Adjacent wood constraint members 172 on the top, bottom, left, and right sides are joined to each other by screws 174 that pass from one wood constraint member 172 through the spacer member 176 and reach the inside of the other wood constraint member 172.

[0061] In this embodiment, since the core material 170 has a cross-shaped cross section, buckling can occur in any direction in Figure 7, but since the core material 170 is restrained from above, below, left and right by four wooden restraint materials 172, buckling in any direction can be prevented.

[0062] 8 is a cross-sectional view of a brace 220 according to a third embodiment of the present invention, taken along a plane perpendicular to the longitudinal direction. As shown in the figure, the brace 220 according to this embodiment includes a core member 270 having a circular cross-section, four wooden restraining members 272, and screws 274.

[0063] The cross-sectional shape of the wood constraint members 272 is a rectangle with one corner cut out in a quarter arc shape to match the cross-sectional shape of the core material 270. The four wood constraint members 272 sandwich the core material 270 from above, below, left, and right, with the arc-shaped cutout portions surrounding the periphery of the core material 270. Adjacent wood constraint members 272 on the top, bottom, left, and right are joined to each other by screws 274 that are threaded from one wood constraint member 272 to the inside of the other wood constraint member 272. In this embodiment, the core material 270 is a solid round bar, but it may be hollow, that is, cylindrical.

[0064] In this embodiment, since the core material 270 has a circular cross-sectional shape, buckling can occur in any direction, but since the four wooden restraint materials 272 restrain the entire circumference of the core material 270, buckling in any direction can be prevented.

[0065] In the above embodiments, the wooden restraint members 72, 172, 272 are joined with screws 74, 174, 274, but they may also be joined with nails. Since nails do not require pilot holes, they can be installed as easily as screws.

[0066] In addition, in each of the above embodiments, the cross-sectional shape of the wooden restraining members 72, 172, 272 is rectangular or rectangular with notched corners, but this is not limited thereto and any shape that can sandwich and restrain the core material 70, 170, 270 may be used. [Explanation of symbols]

[0067] 1 Column beam frame 1A Upper beam 1B Lower beam 1C, 1D pillar 10 Seismic control structure 20 braces 30 Friction Damper 32, 34 First member 33, 35 Mounting part 36 Second member 38, 40, 42, 44 Slide 46, 48 Friction plate 32a, 34a, 36a, 46a, 48a Insertion holes 50 High Tensile Bolts 52 Nut 54, 60 Washers 56 Disc spring laminate 58 Bush 64 Fasteners 70, 170, 270 core material 72, 172, 272 Wooden restraint material 74, 174, 274 bis 76, 176 Spacer material

Claims

1. A buckling restraint brace attached to a beam-column frame, A core material and a plurality of wood restraint members arranged to sandwich the core material; and screws or nails that connect the plurality of wood restraint materials to each other, A buckling-restrained brace, one end of which is connected to the beam-column frame via a seismic damper.

2. 2. The buckling-restrained brace according to claim 1, wherein one end of the buckling-restrained brace is connected to the column-beam frame via the seismic damper, and the other end is fixed to the column-beam frame.

3. 3. The buckling restraint brace according to claim 1, wherein the core material is a strip-shaped flat steel plate, and the pair of wood restraint members are arranged to sandwich the core material from both sides.

4. 3. The buckling restraint brace according to claim 1, wherein the seismic damper is a hysteretic damper.

5. The buckling restrained brace according to claim 4, wherein the hysteretic damper is a friction damper or a steel damper.

6. A method for installing a buckling restrained brace on a beam-column frame, comprising: The buckling restraint brace is configured by sandwiching a core material between multiple wooden restraint materials and connecting the multiple wooden restraint materials to each other with screws or nails, A method for installing a buckling restrained brace, comprising installing the buckling restrained brace so that at least one end of the buckling restrained brace is connected to the beam-column frame via a seismic damper.

7. A column-beam frame seismic control structure, a buckling restraint brace attached to the beam-column frame; a seismic damper interposed between one end of the buckling restrained brace and the column-beam frame and connecting the buckling restrained brace to the column-beam frame, The buckling restrained brace is A core material and a plurality of wood restraining members sandwiching the core material; A seismic control structure comprising screws or nails that connect the multiple wooden restraint materials to each other.

8. The vibration control structure of a column-beam frame according to claim 7, the seismic damper is a friction damper including a first member and a second member that generates a friction force by sliding relatively with respect to the first member, The first member is attached to an upper beam, a lower beam, or a floor slab in the column-beam frame, A seismic control structure in which a pair of the buckling restraint braces have one end attached to the second member of the friction damper, extend in a V-shape or an inverted V-shape, and have the other end fixed to the column-beam frame.

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