Braces with buckling restraints

Abstract

To make a buckling restraint material have a simple structure, suppress cracking of wood members and delamination between a joined plurality of wood members, and be the buckling restraint material with sufficient strength, in a brace with a buckling restraint material consisting of the plurality of wood members attached around a core member made of steel.SOLUTION: A plurality of wood members are joined to form a buckling restraint material 21 around an elongated plate-shaped core material 11 made of steel. Bolts joining the plurality of wood members penetrate the buckling restraint material in a direction that is approximately perpendicular to the axis of a core material and include a first bolt 25a and a second bolt 25b that are positioned approximately parallel on both sides of the core material. The buckling restraint material includes plywood 23a and 23b which is a laminated member of a plurality of plates, including plates whose wood fiber direction is approximately perpendicular to the axis of the core material, and the plywood is continuous between the first and second bolts on both sides of the core material 11.SELECTED DRAWING: Figure 2

Description

Technical Field

[0004] , , , , , , , , , , , , , , ,

[0001] The present invention relates to a brace used to resist horizontal forces in a building having columns and beams as main structural members, and particularly to a brace provided with a buckling restraint material for suppressing buckling when a compressive force acts.

Background Art

[0002] Generally, braces are arranged in an inclined direction within a frame surrounded by columns and beams, or within a rectangular frame surrounded by beams, foundations, and columns, and restrain deformation when a horizontal force acts on the structural frame. Compressive or tensile forces act on the brace depending on the direction of the horizontal force, and in order to function effectively regardless of the direction of the force, buckling when a compressive force acts must be suppressed. In particular, when plastic deformation is allowed to occur in the brace to absorb vibration energy during an earthquake or the like and attenuate the vibration, it becomes possible to effectively absorb the vibration energy by preventing buckling.

[0003] When the columns and beams are made of steel, generally the braces are also made of steel members. However, in recent years, many techniques for lignifying structural members have been proposed, and proposals for using wooden materials as buckling restraint materials for braces are disclosed in, for example, Patent Document 1 and Patent Document 2. These techniques involve attaching wooden members so as to surround a steel core material and restraining bending deformation of the core material with the wooden members.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] As described in Patent Document 1 or Patent Document 2, in order to attach wooden members to a steel core, it is necessary to attach multiple wooden members to the core in combination. When a buckling restraint material is composed of multiple wooden members in this way, a force acts in a direction that pulls apart the bonds between the multiple wooden members by restraining the buckling of the core. In addition, a force acts that tends to cause cracks in the wooden members whose fibers extend in the axial direction of the core. For this reason, a buckling restraint material made up of combined wooden members is required to firmly bond the multiple wooden members and effectively suppress the occurrence of axial cracks in the wooden members.

[0006] The buckling-restrained brace described in Patent Document 1 is constructed by sandwiching a plate-shaped steel core between layers of laminated timber. However, there may be cases where the strength to maintain the laminated timber attached to both sides of the core is insufficient. Furthermore, cracks may occur in the laminated timber. On the other hand, the buckling-restraining brace described in Patent Document 2 is constructed by fastening multiple wooden members attached around a core material with bolts that penetrate in two directions to form a buckling-restraining member. This results in a complex structure that requires a lot of work for processing and assembling the wooden members.

[0007] The present invention has been made in view of the above circumstances, and its purpose is to provide a brace equipped with a buckling restraint member that has sufficient strength, while having a simple structure for a buckling restraint member consisting of multiple wooden members attached around a steel core, and suppressing cracking of the wooden members and delamination between the multiple joined wooden members. [Means for solving the problem]

[0008] To solve the above problems, the invention according to claim 1 comprises: an elongated steel plate-shaped core material; a buckling restraint member consisting of a plurality of wooden members arranged along the axial direction of the core material and joined together to surround the core material; and bolts connecting the plurality of wooden members, wherein the bolts penetrate the buckling restraint member in a direction substantially perpendicular to the axis of the core material and include a first bolt and a second bolt arranged substantially parallel on both sides of the core material, wherein a plurality of the first bolt and the second bolt are arranged along the axial direction of the core material, the buckling restraint member includes a laminated member made by bonding together a plurality of boards, including boards in which the direction of the wood fibers is substantially perpendicular to the axis of the core material, a pair of the laminated members are arranged at positions opposite each other with the core material in between, and the boards in which the direction of the wood fibers included in the laminated member is substantially perpendicular to the axis of the core material are continuous between the position through which the first bolt penetrates and the position through which the second bolt penetrates. The wood fibers contained in the pair of laminated members are oriented perpendicular to the core material, and the board material and the first bolt The second bolt The present invention provides a brace having a buckling restraint member connected so as to surround the core material.

[0009] In the brace described above, when a compressive force is applied to the steel core, the buckling restraint members, which are arranged to surround the core, restrain the bending deformation of the core, preventing buckling of the core. A force acts on the buckling restraint members from the core perpendicular to its axis, but the tightening force of the bolts in the direction through which the bolts pass prevents cracking of the wood members and delamination between multiple joined wood members. On the other hand, between the two rows of bolts, the inclusion of board material in a pair of laminated members in which the wood fibers extend in a direction approximately perpendicular to the axis of the core prevents cracking and failure of the buckling restraint members. Therefore, the buckling restraint members surround the core and firmly restrain its bending deformation. Furthermore, the multiple bolts connecting the multiple wooden members pass through the core material in the same direction on both sides, simplifying the structure for connecting the multiple wooden members and facilitating the processing and assembly of the wooden members.

[0010] The invention according to claim 2 is a brace having a buckling restraint member as described in claim 1, wherein the buckling restraint member is formed by bringing a pair of laminated members into contact with each other, and the surfaces of the laminated members that come into contact with each other are, The core material A groove is formed into which the wide surface can be inserted perpendicular to the contact surface, and the core material is housed in both grooves provided at opposing positions on the pair of laminated members.

[0011] In this brace, the main part of the buckling restraint is composed of a pair of laminated members, making it possible to efficiently attach and connect them to a plate-shaped core material.

[0012] The invention according to claim 3 is a brace having a buckling restraint member as described in claim 1, wherein the buckling restraint member has a pair of wide-face-facing members that face two wide surfaces which are the front and back surfaces of the core material, and the laminated member includes plywood made by bonding together a plurality of thin plates with a thickness of 0.5 mm to 5.5 mm, and is arranged to face both of the pair of wide-face-facing members.

[0013] In this brace, plywood is used as a continuous laminated member between the positions where the two bolt rows pass through. Because the plywood is made by laminating multiple thin boards with wood fibers growing in nearly perpendicular directions, it effectively prevents cracking and failure of the buckling restraint member between the positions where the two bolt rows pass through. Furthermore, by combining the wide surface of the core material with a pair of wide surface opposing members and the aforementioned plywood, it becomes possible to accurately surround the core material in a way that restrains its buckling with simple processing.

[0014] The invention according to claim 4 is a brace having a buckling restraint member as described in claim 3, wherein the surface of the plywood opposite to the surface facing the wide surface opposing member It is in contact with the outermost wooden member, and the wood fibers are continuous in the axial direction of the core material, reinforcing the bending rigidity of the core material in the axial direction. A rigid reinforcing member is provided, and the first bolt and the second bolt fasten the rigid reinforcing member, the plywood, and the wide surface-facing member together, creating a pressure contact.

[0015] In this brace, rigid reinforcing members are layered on top of plywood and fastened with bolts, allowing for an effective increase in the bending rigidity of the buckling-restraining member with a simple structure.

[0016] The invention according to claim 5 is a brace having a buckling restraint member as described in claim 1, wherein the pair of laminated members are each facing the wide surface of the core material, a pair of spacing members are interposed between the pair of laminated members on both sides of the core material to maintain the distance between the laminated members, and the bolts penetrate the laminated members and the spacing members.

[0017] In this brace, the amount of processing required for the pair of laminated members and spacing members that constitute the buckling restraint member is reduced, and the number of members is also reduced, making it possible to attach them to the core material efficiently.

[0018] The invention according to claim 6 is a brace having a buckling restraint member as described in any of claims 1 to 5, wherein a plurality of wooden members constituting the buckling restraint member are in contact with each other across the contact surface, The wood fibers penetrate multiple wood members that are continuous in the axial direction of the core material. Multiple lag screws or bolts are screwed into the buckling restraint member, and the number of lag screws or bolts used is sufficient to restrain the relative displacement along the contact surface between the two wooden members that come into contact when bending deformation occurs in the buckling restraint member.

[0019] When multiple long wooden members are joined in the axial direction of the core material, a shear force acts between the joined wooden members when a bending moment acts on the buckling restraint member, generating a force that tends to cause slippage between the contacting wooden members, that is, relative displacement along the contact surface. In the brace described above, lag screws or screws driven in across the contact surfaces between the wooden members prevent the slippage between the wooden members due to the shear force, thereby suppressing the reduction in the bending rigidity of the buckling restraint member caused by the slippage between the wooden members.

[0020] The invention according to claim 7 is a brace having a buckling restraint material according to any one of claims 1 to 6, wherein in the wooden member, lag screws or screws are screwed in such a manner as to extend from a position where the first bolt penetrates to a position where the second bolt penetrates in a direction substantially perpendicular to the axial direction of the core material.

[0021] In this brace, the position between the position where the first bolt penetrates and the position where the second bolt penetrates is effectively reinforced by lag screws or screws, and cracking or breakage of the buckling restraint material is suppressed.

[0022] The invention according to claim 8 is a brace having a buckling restraint material according to any one of claims 1 to 7, wherein an elastic body layer is formed between the outer peripheral surface of the core material and the surface of the buckling restraint material facing the outer peripheral surface.

[0023] In this brace, when a compressive force acts on the core material, the lateral force acting on the buckling restraint material from the core material is dispersed by the elastic body layer. Thereby, it is possible to avoid a large force acting concentratedly on the buckling restraint material and suppress the breakage of the buckling restraint material.

[0024] The invention according to claim 9 is a brace having a buckling restraint material according to any one of claims 1 to 7, wherein a film having a friction reducing effect and water repellency is formed on the surface of the buckling restraint material facing the outer peripheral surface of the core material.

[0025] In this brace, when a compressive force or a tensile force acts on the core material, the force that restrains the axial strain of the core material by the buckling restraint material is reduced. Thereby, the core material expands and contracts smoothly. In addition, penetration of moisture into the surface of the buckling restraint material facing the core material is prevented, and a good drying state is maintained.

Effects of the Invention

[0026] As described above, in the brace having the buckling restraint member of the present invention, the buckling restraint member made of wood material can be attached around the core material made of steel with a simple structure, and it is possible to effectively suppress the buckling of the core material without causing cracking of the wood material or delamination between multiple joined wood material members. [Brief explanation of the drawing]

[0027] [Figure 1] This is a schematic side view showing a portion of the structural frame of a building in which a brace, which is one embodiment of the present invention, is used. [Figure 2] Figure 1 shows a schematic perspective view of a part of a brace with a buckling restraint member. [Figure 3] Figure 2 is a schematic cross-sectional view of a brace having a buckling restraint member. [Figure 4] Figure 2 is a schematic cross-sectional view of a brace having a buckling restraint member. [Figure 5] Figure 2 is an exploded assembly diagram of a brace with a buckling restraint member. [Figure 6] A schematic perspective view showing a portion of a brace having a buckling restraint member, which is another embodiment of the present invention. [Figure 7] Figure 6 is a schematic cross-sectional view of a brace having a buckling restraint member. [Figure 8] A schematic perspective view showing a portion of a brace having a buckling restraint member, which is another embodiment of the present invention. [Figure 9] Figure 8 is a schematic cross-sectional view of a brace having a buckling restraint member. [Modes for carrying out the invention]

[0028] The embodiments of the present invention will be described below with reference to the drawings. Figure 1 is a schematic side view showing a portion of the structural frame of a building in which a brace, which is one embodiment of the present invention, is used. Figure 2 is a schematic perspective view showing a portion of the brace having a buckling restraint member as shown in Figure 1, Figures 3 and 4 are schematic cross-sectional views, and Figure 5 is an exploded assembly view of the same brace. This brace 1 is installed within the frame of the structural frame, which is formed in a rectangle by columns 2 and 3, the beam 4 of the lower floor, and the beam 5 of the upper floor. The two braces are positioned with their inclination directions opposite to each other, with their lower ends joined to the joint between the beam 4 of the lower floor and columns 2 and 3, and their upper ends joined to the center of the span of the beam 5 of the upper floor. This suppresses inter-story deformation between the lower and upper floors when horizontal forces act on a building whose main structural members are columns and beams, with compressive force acting on one of the two braces 1 and tensile force acting on the other.

[0029] The brace 1 described above comprises a core material 11 made of steel and a buckling restraint member 21 provided so as to surround the core material. The core material 11 described above is made of a strip-shaped steel plate, and has widened sections 11a at both ends that are wider than the central section. End reinforcing members 12 made of steel plates of approximately the same thickness as the strip-shaped core material 11 are welded to both sides of the widened sections 11a, almost perpendicular to the core material 11, resulting in a cross-shaped cross section. Multiple bolt holes 13 are provided in both the widened sections 11a and the end reinforcing members 12, and they are bolted to the structural frame via splice plates that are placed between the connecting plate 6 provided on the structural frame and the core material.

[0030] The buckling restraint member 21 described above is made up of multiple wooden members and is provided to surround the core material 11 along its axial direction. The multiple wooden members include a pair of wide-face opposing members 22a, 22b that face the two wide faces that are the front and back of the core material, plywood 23a, 23b that have width in the thickness direction of the core material 11 and abut against both of the pair of wide-face opposing members, and rigid reinforcing members 24a, 24b that abut against the opposite side of the plywood that faces the wide-face opposing members 22a, 22b. These wooden members have approximately the same length in the axial direction of the core material 11 and are long enough to surround a portion of the widened section 11a from the central part of the core material 11 to near both ends. As shown in Figure 5, the wide facing members 22a, 22b, the plywood 23a, 23b, and the rigid reinforcing members 24a, 24b are joined together by having bolt holes 30 formed at corresponding positions during joining, passing bolts 25a, 25b through the respective bolt holes, and tightening them with nuts 26a, 26b.

[0031] The wide-faced opposing members 22a and 22b described above can be made of solid wood, laminated veneer lumber (LVL), cross-laminated timber (CLT), etc., and the width of the surface facing the wide surface of the core material 11 is slightly wider than the width of the central part of the core material 11. The opposing surfaces are in contact with the wide surface of the core material 11 or there is a small gap between them, and they face both sides of the core material 11. When positioned in contact with the core material 11, they are not strongly pressed together, but rather the core material 11 and the wide-faced opposing members 22a and 22b are allowed relative displacement along the opposing surfaces in the axial direction of the core material 11. When there is a gap between them, the gap should be small enough to restrain the bending deformation of the core material 11 and effectively suppress buckling, for example, it is desirable to have a gap of about 1.0 mm or less.

[0032] Grooves 22c are formed on the surfaces of the wide-face-facing members 22a and 22b that face the core material 11, near their ends, into which the end reinforcing members 12, which are provided at the ends of the core material 11, fit. Within these grooves 22c, the end reinforcing members 12 and the wide-face-facing members 22a and 22b are in contact or close proximity, allowing for relative displacement in the axial direction. Furthermore, the grooves 22c are formed with a margin in the length direction of the end reinforcing members 12 so that the relative displacement of the end reinforcing members is not constrained by the wide-face-facing members 22a and 22b when the core material 11 expands or contracts.

[0033] The above-mentioned plywood 23a and 23b are laminated members of the present invention, and for example, a plurality of thin boards with a thickness of 0.5 mm to 5.5 mm can be used, which are alternately bonded together so that the direction of the fibers is approximately perpendicular to each other. It is desirable to use plywood 23a and 23b with a thickness of about 10 mm to 30 mm. The plywood panels 23a and 23b described above have a width that faces both of the pair of wide facing members 22a and 22b, which are arranged to face both sides of the core material 11. A pair of plywood panels are provided that abut the wide facing members 22a and 22b, which are arranged on both sides of the core material 11, sandwiching them in between. The surfaces of the plywood panels 23a and 23b are in contact with the narrower surfaces of the core material 11 or are facing each other with a small gap between them. Slits 23c are provided near the ends of these plywood panels 23a and 23b so as not to interfere with the widened portion 11a of the core material. The slits 23c are wider than the range of the widened portion 11a in the axial direction of the core material 11, and the widened portion 11a is housed within these slits 23c, allowing for relative displacement when the core material 11 expands or contracts.

[0034] The rigid reinforcing members 24a and 24b described above, like the wide-face-facing members 22a and 22b described above, can be made of solid wood, laminated veneer, orthogonal laminated board, etc., and are provided overlapping the entire surface of the plywood 23a and 23b. The dimensions of the cross-section of these rigid reinforcing members 24a and 24b can be appropriately set to provide the bending rigidity necessary to suppress buckling of the core material 11.

[0035] As shown in Figure 3(a), the bolts 25a and 25b are arranged almost parallel to the wide surfaces of the core material 11. The first bolt 25a is positioned away from one wide surface of the core material 11, and the second bolt 25b is positioned away from the other wide surface. The first bolt 25a and the second bolt 25b penetrate the rigid reinforcing members 24a, 24b, plywood 23a, 23b, and wide surface opposing members 22a, 22b that are laminated to surround the core material 11, and multiple bolts of each type are arranged along the axial direction of the core material 11. Washers 27 are attached to the heads of each bolt 25a and 25b, and to the nuts 26a, 26b that are twisted onto these bolts, so that the tightening force of the bolts 25a and 25b is smoothly transmitted to the wooden members.

[0036] In this type of brace 1, the core material 11, which is connected at both ends to the structural frame of the building, resists inter-story deformation between the upper and lower floors of the building. When compressive force is applied, bending deformation is restrained by the buckling restraint member 21, and buckling is suppressed. Furthermore, when plastic deformation in the compressive direction occurs in the core material 11, buckling is restrained, causing the stress-strain curve to form a large loop, making it possible to effectively absorb vibrational energy. On the other hand, the buckling restraint member 21 is constructed by firmly connecting multiple wooden members with bolts, and between the first bolt 25a and the second bolt 25b, plywood 23a and 23b having strong tensile strength in the axial direction of the core material 11 and in the direction perpendicular thereto are placed. This prevents cracking or breakage of the buckling restraint member 21 between the first bolt 25a and the second bolt 25b. Furthermore, since all the bolts 25a and 25b that combine and connect the multiple wooden members are arranged in the same direction, the structure is simplified, making it possible to efficiently assemble it around the core material 11.

[0037] Furthermore, in order to enhance the integrity of the rigid reinforcing members 24a, 24b, plywood 23a, 23b, and wide surface contact members 22a, 22b, as shown in Figure 4(a), lag screws 28 or screws can be driven through the rigid reinforcing members 24a, 24b and plywood 23a, 23b and into the wide surface contact members 22a, 22b. This allows for strong pressure bonding of the wood members and effectively suppresses slippage along the contact surfaces between members, i.e., relative displacement. Furthermore, when using solid wood or veneer laminated lumber (LVL) with the fiber direction of the veneer aligned with the axial direction of the core material 11 as rigid reinforcing members 24a and 24b, screws 29 can also be screwed in from the sides of the rigid reinforcing members 24a and 24b, as shown in Figure 4(b). This prevents the rigid reinforcing members 24a and 24b from splitting between the first bolt 25a and the second bolt 25b. In this case, it is desirable to screw the screws 29 from the position where the first bolt 25a penetrates to the position where the second bolt 25b penetrates.

[0038] On the other hand, a coating that reduces friction and is water-repellent can be formed on the surfaces of the wide-face-facing members 22a, 22b and the plywood 23a, 23b that face the core material 11. The coating can be formed, for example, by applying or spraying a silicone resin. This prevents moisture from penetrating near the surfaces of the wide-face-facing members 22a, 22b and the plywood 23a, 23b that face the core material 11, and reduces friction between the core material 11 and the buckling restraint member 21, so that the axial deformation of the core material 11 is not restrained by the buckling restraint member 21. Therefore, the effect of absorbing vibration energy when plastic deformation occurs in the core material 11 is well maintained. Furthermore, a thin elastic member can be interposed between the wide surface-facing members 22a, 22b and the plywood 23a, 23b and the core material 11. The thin layer of the elastic member is preferably 1 mm or less in thickness and can be formed by spraying or coating liquefied synthetic rubber onto the surface of the core material 11 or the wide surface-facing members 22a, 22b.

[0039] In the brace 1 described above, the central portion of the core material 11 is in contact with or slightly gapped from the surfaces of the plywood 23a and 23b. However, grooves may be provided in the plywood so that the side edges of the core material fit into these grooves. In this case, the surface of the wide-faced opposing member that faces the core material is smaller than the wide surface of the core material.

[0040] Figure 6 is a schematic perspective view showing a portion of a brace, which is another embodiment of the present invention, and Figure 7 is a cross-sectional view of the same brace. In this brace 8, the buckling restraint member 31 surrounds the core material with two laminated wooden members 32a and 32b, which are fastened and joined together with bolts 33a and 33b. The core material 14 is housed in a space formed by cutting grooves into the opposing surfaces of the two wooden members 32a and 32b. The core material 14 used in this brace 8 is the same as the core material 11 used in brace 1 shown in Figures 2 to 5.

[0041] The above-mentioned wood members 32a and 32b are laminated members of the present invention, and use laminated material made by alternately bonding multiple veneers in which the fibers grow in a perpendicular direction. The thickness of each veneer can be, for example, about 3 mm to 7 mm, and the veneers are laminated almost parallel to the surface where the two wood members 32a and 32b are joined. Each of the two wooden members 32a and 32b has a groove cut into its opposite surface. This groove 32c is positioned precisely opposite to the two wooden members 32a and 32b when they are superimposed, and the width of the groove 32c is slightly larger than the thickness of the strip-shaped steel plate that makes up the core material 14. The depth of the groove is such that it can accommodate half of the wide surface of the core material 14. Therefore, as shown in Figure 7(a), the core material 14 can be housed in the groove 32c formed in both wooden members 32a and 32b, and the buckling restraint member 31 is formed by bringing these wooden members 32a and 32b into close contact with each other. In this way, the core material 14 housed in the groove 32c and the inner surface of the groove 32c are in contact or separated by a small gap.

[0042] The wooden members 32a and 32b described above are long enough to surround the central part of the core material 14 and a portion of the widened sections 14a near both ends. In the widened sections 14a, as shown in Figure 7(b), the end reinforcing members 15 are provided, surrounding the core material 14 which has a cross-shaped cross section. In other words, near both ends of the wooden members 32a and 32b, notches 32d are provided on both sides of the groove 32c, with a depth of approximately half the thickness of the end reinforcing member 15, so that the end reinforcing member 15 fits between the two wooden members 32a and 32b. These notches 32d are formed wider than the area in which the end reinforcing member 15 is provided to prevent interference with the end reinforcing member 15 when the core material 14 expands or contracts. Furthermore, the groove 32c into which the core material 14 is inserted is deeper in the parts corresponding to the widened sections 14a at both ends.

[0043] The bolts 33a and 33b that connect the two wooden members 32a and 32b are the same bolts used in the embodiments shown in Figures 2 to 5, with multiple first bolts 33a and second bolts 33b arranged on both sides of the core material 14. These bolts 33a and 33b penetrate both wooden members 32a and 32b in a direction along the wide surface of the core material 14, and nuts 34a and 34b are twisted together to fasten the two wooden members 32a and 32b. The joint surfaces of the two wooden members 32a and 32b can be bonded by applying adhesive in addition to being fastened with bolts 33a and 33b.

[0044] In this brace 8, similar to brace 1 shown in Figures 2 to 5, buckling of the core material 14 is prevented by a buckling restraint, while expansion and contraction in the axial direction of the core material 14 are permitted. The two wood members 32a and 32b are made of laminated material in which multiple veneers with fibers growing in orthogonal directions are alternately bonded together, and they have high tensile strength in the direction perpendicular to the axis of the core material 14. Therefore, the two wood members 32a and 32b are firmly joined by bolts 33a and 33b, and cracking or breakage between the first bolt 33a and the second bolt 33b is prevented. Furthermore, the buckling restraint member 31 is mainly composed of two wooden members 32a and 32b and bolts 33a and 33b, allowing the core material 14 to be surrounded with a small number of members, thus simplifying the assembly process.

[0045] In this brace 8, laminated timber made of thin veneers is used as the wood members 32a and 32b, but cross-laminated timber (CLT) with a veneer thickness of about 15 mm to 30 mm can be used instead. Also, screws can be driven in across the first bolt 33a and the second bolt 33b to reinforce the wood members against cracking. On the other hand, a silicone resin coating may be formed in the groove 32c formed in the wood members 32a and 32b, or a thin layer of elastic material may be formed.

[0046] Figure 8 is a schematic perspective view showing a portion of a brace, which is another embodiment of the present invention, and Figure 9 is a cross-sectional view of the same brace. In this brace 9, the buckling restraint member 41 is mainly composed of two rectangular cross-section wooden members 42a and 42b, two spacing members 43a and 43b that maintain the distance between the two wooden members 42a and 42b when they are joined together, and bolts 44a and 44b that fasten and join them together. The two wooden members 42a and 42b face the wide surface of the core material 16, respectively, and are joined by sandwiching the spacing members 43a and 43b which are positioned on both sides of the core material 16, thus surrounding the core material 16 together with the spacing members 43a and 43b. The core material 16 is the same as the brace shown in Figures 2 to 5, and has widened sections 16a near both ends, to which end reinforcing members 17 are attached.

[0047] The above-mentioned wood members 42a and 42b are laminated members of the present invention, and consist of a laminated material made by alternately bonding multiple veneers in which the fibers grow in a perpendicular direction. The veneers are laminated so as to be almost parallel to the faces of the two wood members 42a and 42b, and the thickness of each veneer can be, for example, about 3 mm to 7 mm. The spacing members 43a and 43b described above are wooden boards with a thickness slightly greater than that of the core material 16. As shown in Figure 9(a), a pair of these members are placed on both sides of the core material 16 and sandwiched between two wooden members 42a and 42b. The first bolt 44a and the second bolt 44b pass through the two wooden members 42a and 42b and the spacing members 43a and 43b sandwiched between them on both sides of the core material 16, and fasten them together. Therefore, the core material 16 is surrounded by the two wooden members 42a and 42b and the two spacing members 43a and 43b, and the core material 16 and the two wooden members 42a and 42b are in contact or with a small gap between them. In addition, the spacing members 43a and 43b are in contact with or with a small gap between them and the narrow side of the core material 16, thus restraining the buckling of the core material 16. Furthermore, the contact surfaces between the two wooden members 42a, 42b and the spacing members 43a, 43b can be fastened with bolts 44a, 44b, and can also be bonded by applying adhesive.

[0048] The wooden members 42a, 42b and the spacing members 43a, 43b are of a length that can surround the central part of the core material 16 and a portion of the widened section 16a near both ends. In the widened section 16a, as shown in Figure 9(b), grooves 42d are formed in the wooden members 42a, 42b, and the end reinforcing members 17 attached to the core material 16 are housed in these grooves. These grooves 42d are provided wider than the area corresponding to the end reinforcing members 17 when no compressive force is applied to the core material 16, so that the wooden members 42a, 42b do not interfere with the end reinforcing members 17 when compressive deformation occurs in the core material 16.

[0049] In this type of brace 9, buckling can be restrained without restricting the expansion and contraction of the core material 16. Furthermore, laminated material with perpendicular fiber directions is used for the two wood members 42a and 42b, preventing cracking or breakage between the first bolt 44a and the second bolt 44b. Furthermore, the buckling restraint material 41 can surround the core material 16 with simple processing, improving work efficiency.

[0050] Furthermore, in this brace 9, cross-laminated timber (CLT) can be used as the wood members 42a and 42b, and screws can be screwed in in the direction crossing the first bolt 44a and the second bolt 44b for reinforcement. In addition, a silicone resin coating may be formed on the surface of the wood member and the gap-holding member that faces the core material, or a thin layer of elastic material may be formed.

[0051] The brace having the buckling restraint member described above is an embodiment of the present invention, and the present invention is not limited to these, but can be designed as appropriate within the scope of the present invention. [Explanation of symbols]

[0052] 1: Brace, 2: Column, 3: Column, 4: Beam on the lower floor, 5: Beam on the upper floor, 6: Connecting plate, 8: Brace, 9: Brace 11: Core material, 11a: Widened section of core material, 12: End reinforcing member, 13: Bolt hole, 14: Core material, 14a: Widened section of core material, 15: End reinforcing member, 16: Core material, 16a: Widened section of core material, 17: End reinforcing member, 21: Buckling restraint member, 22a, 22b: Wide face-facing member, 22c: Groove provided in the wide face-facing member, 23a, 23b: Plywood, 23c: Slit, 24a, 24b: Rigidity reinforcing member, 25a: First bolt, 25b: Second bolt, 26a, 26b: Nut, 27: Washer, 28: Lag screw, 29: Screw, 30: Bolt hole, 31: Buckling restraint member, 32a, 32b: Wooden member, 32c: Groove provided in the wooden member, 32d: Notch, 33a, 33b: Bolt, 34a, 34b: Nut, 41: Buckling restraint member, 42a, 42b: Wooden member, 42d: Groove provided at the end of the wooden member, 43a, 43b: Spacing member, 44a: First bolt, 44b: Second bolt

Claims

1. A long, slender, plate-shaped core made of steel, A buckling restraint member consisting of a plurality of wooden members arranged along the axial direction of the core material and joined together to surround the core material, It has bolts for joining multiple wooden members, The bolts penetrate the buckling restraint member in a direction substantially perpendicular to the axis of the core material, and include a first bolt and a second bolt arranged substantially parallel to each other on both sides of the core material. Multiple bolts are arranged along the axial direction of the core material, The buckling restraint member includes a laminated member made by bonding together multiple boards, including a board in which the direction of the wood fibers is approximately perpendicular to the axis of the core material. The laminated members are arranged in pairs at positions opposite each other with the core material in between. The board material in which the direction of the wood fibers contained in the laminated member is approximately perpendicular to the axis of the core material is continuous between the position where the first bolt penetrates and the position where the second bolt penetrates. A brace having a buckling restraint member, characterized in that the wood fibers contained in a pair of laminated members are oriented perpendicular to the core material, and the first bolt and the second bolt are connected so as to surround the core material.

2. The buckling restraint member is constructed by bringing a pair of the laminated members into contact with each other. The surfaces of the laminated members that come into contact with each other are formed in grooves into which the wide surface of the core material can be inserted perpendicular to the contact surface. The brace having a buckling restraint member according to claim 1, characterized in that the core material is housed in grooves provided at opposing positions of the pair of laminated members.

3. The buckling restraint member has two wide surfaces that are the front and back surfaces of the core material, and a pair of wide surface opposing members that are opposite to each other. The brace having a buckling restraint member according to claim 1, characterized in that the laminated member includes plywood made by bonding together a plurality of thin plates having a thickness of 0.5 mm to 5.5 mm, and is arranged to face both of the pair of wide-faced opposing members.

4. A stiffening member is provided, which is the outermost wood-based member that abuts against the surface of the plywood opposite to the surface facing the wide surface-facing member, and has wood fibers running continuously in the axial direction of the core material, thereby reinforcing the bending stiffness of the core material in the axial direction. The brace having a buckling restraint member according to claim 3, characterized in that the first bolt and the second bolt fasten and press together the rigid reinforcing member, the plywood, and the wide surface-facing member.

5. The pair of laminated members are each facing the wide surface of the core material, Between the pair of laminated members, a pair of spacing members are interposed on both sides of the core material to maintain the distance between the laminated members. The brace having a buckling restraint member according to claim 1, characterized in that the bolt penetrates the laminated member and the spacing member.

6. Multiple lag screws or bolts are screwed into the contact surfaces where the multiple wooden members constituting the buckling restraint member abut each other, so that the wood fibers penetrate the multiple wooden members that are continuous in the axial direction of the core material. The brace having a buckling restraint member according to any one of claims 1 to 5, characterized in that the number of lag screws or screws used is sufficient to restrain the relative displacement along the contact surface between the two wooden members that come into contact when bending deformation occurs in the buckling restraint member.

7. A brace having a buckling restraint member according to any one of claims 1 to 6, characterized in that a lag screw or bolt is screwed into the wooden member in a direction substantially perpendicular to the axial direction of the core material, from the position through which the first bolt penetrates to the position through which the second bolt penetrates.

8. A brace having a buckling restraint member according to any one of claims 1 to 7, characterized in that an elastic layer is formed between the outer surface of the core material and the surface of the buckling restraint member facing the outer surface.

9. A brace having a buckling restraint member according to any one of claims 1 to 7, characterized in that a coating having a friction-reducing effect and water-repellent properties is formed on the surface of the buckling restraint member facing the outer circumferential surface of the core material.

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