JP6169486B2 - Buckling restraint brace - Google Patents

Description

  The present invention relates to a buckling-restrained brace that is incorporated in a framework of a structure and absorbs vibration energy and attenuates vibration in the event of an earthquake or the like.

Each of the conventional buckling-restraining braces is configured to stiffen the buckling of the core material by arranging the core material on the inside and the restraining material on the outside, such as sandwiching the core material from both sides with a pair of restraining materials. Has been. An example is shown in FIGS.
The buckling-restraining brace 21 in the example of FIG. 1 has a long and thin plate-like core member 22 and a pair of restraining members 23 and 23 arranged to face each other along both surfaces of the core member 22. Both ends of the core material 22 are joint portions 22B to be joined to the building frame, and the restraining material 23 is disposed so as to cover substantially the entire core material 22 excluding the tip side of the joint portion 22B of the core material 22.

  As shown in a sectional view in FIG. 9, the pair of restraining members 23, 23 is a groove steel 24 that opens in a direction facing the core member 22, and a concrete system filled in the groove steel 24. It consists of material 25. An unbond material 26 is attached to the surface of the restraining material 23 facing the core material 22. In this example, the core 22 has a narrowed portion 22A having a narrower width than the others at the center in the longitudinal direction, and spacers 27 are disposed on both sides of the narrowed portion 22A.

JP 2004-244833 A JP 2007-191987 JP 2009-161937

Conventional buckling-restraining braces are configured by arranging the core material on the inside and the constraint material on the outside, such as sandwiching the core material from both sides with a pair of constraint materials, and thus have the following problems. .
(1) Since the core material 22 is covered with the restraining material 23, the damage condition of the core material 22 cannot be confirmed after an earthquake.
(2) Since only the damaged core material 22 cannot be replaced, a large-scale construction is required for the replacement, and the cost increases.
(3) Since a common conventional buckling-restrained brace has one core member 22, the joint portion 22B of the core member 22 is sandwiched between the joint plate 31 of the building frame and the splice plate 28 as shown in FIG. Need to be connected, and the joint portion 22B becomes long. In addition, when the joint portion 22B is long, reinforcement by the ribs 29 and the like for suppressing local buckling also increases.
(4) There is no fail-safe mechanism that suppresses extreme deformation of buildings during an earthquake.

  An object of the present invention is to provide a buckling-restrained brace that can easily confirm the state of damage to a core material due to an earthquake and can easily replace only the core material.

  The buckling-restraining brace of the present invention includes a pair of plate-like core members that are arranged in parallel to each other so that one side faces each other and both ends are connected to a building frame, and sandwiched between these core members. A restraining material that restrains buckling, and the pair of core members are joined together with the restraining material by a plurality of bolts arranged at intervals in the longitudinal direction.

  According to this configuration, the restraint material is sandwiched between the pair of core materials, and since the core material is on the outside, it is easy to check the damage status of the core material due to the earthquake, and it is also easy to replace only the core material. it can. Moreover, since there are two core members, when the core member is joined to the joint plate of the building frame, the joint plate can be sandwiched between the ends of the two pairs of core members, and a splice plate is not necessary. Therefore, the joint portion at the end of the core material can be shortened, and reinforcement with ribs or the like for preventing local buckling can be eliminated or reduced.

In the present invention, the core material may be exposed so as to be visible from the outside.
If the core material is exposed from the outside, it is possible to check the damage status of the core material without disassembling the members, making it easier to check and replacing the core material more easily. Become.

In the present invention, the pitch of the bolts may be a constant pitch, and this pitch may be matched to the buckling length of the core material.
When the bolt pitch matches the buckling length of the core material, the compression strength (buckling strength) of the core material can be determined by the bolt pitch.

In this invention, it is good also considering the bolt insertion hole provided in the said restraint material as a long hole long in the longitudinal direction of the said core material.
If the bolt insertion hole is a long hole, by adjusting the length of the bolt insertion hole, an upper limit can be set for the deformation performance of the core material, and the restraint material also functions as a deformation suppression device for the core material. Therefore, a fail-safe mechanism that suppresses large deformation of the building can be added.

  The buckling-restraining brace of the present invention includes a pair of plate-like core members that are arranged in parallel to each other so that one side faces each other and both ends are connected to a building frame, and sandwiched between these core members. A restraining material that restrains buckling, and the pair of core materials are joined together with a plurality of bolts arranged at intervals in the longitudinal direction together with the restraining material. It is easy to replace only the core material.

(A) is a front view of the buckling restraint brace concerning one Embodiment of this invention, (B) is the same sectional drawing. (A) is a top view of the buckling restraint brace, (B) is a buckling image diagram of the core material in the buckling restraint brace. It is a top view which arranges and shows two core materials in the buckling brace. (A) is the front view of the restraint material in the buckling brace, (B) is the side view. (A)-(D) are front views which show the various examples of a core material, (E) is sectional drawing of the core material shown to the figure (D). (A)-(D) are side views of the buckling restraint brace concerning each embodiment. It is a disassembled perspective view of a prior art example. It is an external appearance perspective view of the conventional example. It is sectional drawing of the same prior art example. It is explanatory drawing which shows the connection part to the building frame of the prior art example.

  An embodiment of the present invention will be described with reference to FIGS. 1A and 1B show a front view and a cross-sectional view of a buckling restrained brace of this embodiment. The buckling-restraining brace 1 includes a pair of plate-like core members 2 and 2 arranged in parallel with each other so that one side faces each other, and a seat of the core member 2 sandwiched between the core members 2 and 2. And one restraint material 3 for restraining bending. The pair of core members 2 and 2 are joined together with the restraint member 3 by a plurality of bolts 4 arranged at intervals in the longitudinal direction. Both ends of the core material 2 are connected to the building frame.

  As shown in FIG. 3, the core material 2 is made of an elongated flat steel plate, and an intermediate portion in the length direction is a narrow width portion 2 </ b> A having notches 2 a along the length direction on both sides. The narrow portion 2A yields from an early stage of interlayer displacement during an earthquake or the like, and becomes a portion where large energy can be absorbed. Both end portions of the core material 2 that protrude from the restraint material 3 are joint portions 2B that are connected to a steel frame material 10 such as a column or a beam that is a building frame.

  The bolts 4 that join the pair of core members 2 and 2 together with the constraining member 3 are arranged at a constant pitch P as shown in FIG. 2A in a section overlapping the constraining member 3 in the length direction of the core member 2. At this pitch P, the core material 2 is provided with a plurality of bolt insertion holes 7 as shown in FIG. FIGS. 2A and 2B show a plan view of the buckling restrained brace 1 and a buckling image diagram of the core member 2. The core material 2 is buckled and deformed on both the front and back surfaces so as to wave with a constant buckling length p as shown in FIG. The pitch P of the bolt 4 is matched to this buckling length p. Both ends of the core material 2 become joint portions 2B, and the joint portions 2B are provided with bolt insertion holes 8 for bolting to the building frame as shown in FIG. High-strength bolts are used as bolts to be joined to the building frame.

As shown in FIG. 4, the restraining material 3 is made of an H-shaped steel having higher rigidity than the core material 2, and a plurality of bolt insertion holes 9 are provided in the web portion 3 a according to the pitch P of the bolt 4. Here, the bolt insertion hole 9 is a long hole that is long in the longitudinal direction of the core member 2, so that the restraint member 3 is independent from the deformation of the core member 2. Therefore, a medium bolt is used instead of a high-strength bolt for the bolt 4 that sandwiches the restraint material 3 with the core material 2. However, the bolt insertion hole 9 at the center in the longitudinal direction of the restraining material 3 is not a long hole but a circular hole, and the bolt insertion hole 9 closer to the end of the restraining material 3 is gradually formed longer. The bolt insertion hole 9 made of this long hole is, for example, a position where the longitudinal end of the restraining material in the longitudinal direction is aligned with the bolt insertion hole 7 of the core material 2. Each of the bolts 4 is inserted through the bolt insertion hole 7 of the pair of core members 2 and 2 and the bolt insertion hole 9 of the restraint member 3, and the core members 2 and 2 and the restraint member 3 are fastened by the nut 4 a.
There are no members covering the outer surfaces of the pair of core members 2 and 2 that sandwich the restraint member 3, and the core member 2 is exposed so as to be visible from the outside.

According to the buckling constraining brace 1 having this configuration, the constraining material 3 is sandwiched between the pair of core members 2 and 2, and these are joined by a plurality of bolts 4 arranged in the longitudinal direction. For this reason, when a compressive force acts on the buckling restrained brace 1 due to an earthquake or the like, the buckling of the core material 2 is restrained by the restraining material 3 and functions as a buckling restrained brace that absorbs vibration energy.
Unlike the conventional buckling-restrained brace, two core members 2 are arranged on the outer surface side. Therefore, it is easy to check the damage state of the core member 2 due to an earthquake, and it is easy to replace only the core member 2 Can be done. Moreover, since the core material 2 is made into two sheets, the core material 2 can be joined to the building frame by sandwiching the joining plate 13 provided in the building frame with the joint portion 2B at the end of the two core materials 2. . Therefore, the connecting plate (splice plate 28 in FIG. 10) that is sandwiched between the joint portion at the end of the core member and the connecting plate on the building side, which has been necessary in the past, becomes unnecessary. Further, since the connecting plate is unnecessary, the length of the joint portion 2B of the core material 2 can be shortened, and the reinforcement by the ribs of the joint portion 2B can be reduced or omitted, and the structure of the joint portion 2B is simplified. it can.

  Further, in this embodiment, since the core material 2 is exposed from the outside so as to be visible from the outside, it is possible to confirm the damage status of the core material 2 without partially disassembling the member, and to confirm more easily. This makes it easier to replace the core material 2. More specifically, if the core is damaged during an earthquake, only the core material 2 needs to be replaced, and the weight of the replacement portion can be reduced. Therefore, the repair cost for replacing the buckling restraint brace 1 after the earthquake can be reduced. . For this reason, this buckling restraint brace 1 becomes more effective when it is used as a buckling restraint brace of a type in which a part is replaced and restored after the occurrence of a large earthquake.

  Further, in this embodiment, the arrangement pitch of the bolts 4 for joining the restraining material 3 to the core material 2 is set to a constant pitch P, and this pitch P is matched to the buckling length p of the core material 2 as shown in FIG. Therefore, the compression strength (buckling strength) of the core material 2 can be determined by the pitch P of the bolts 4.

  In this embodiment, since the bolt insertion hole 9 provided in the restraint material 3 is a long hole in the longitudinal direction of the core material 2 as shown in FIG. 4, by adjusting the length of the bolt insertion hole 9, An upper limit can be set for the deformation performance of the core material 2. That is, the range in which the core material 2 is extended when the pulling force is applied is restricted by the restraint material 3 within a range in which the bolt 4 can move within the bolt insertion hole 9. Thus, the restraint material 3 will work as a deformation suppressing device for the core material 2, and a fail-safe mechanism for suppressing large deformation of the building can be added. At this time, as the core material 2 moves away from the center in the longitudinal direction, the amount of deformation from the center increases. However, since each bolt insertion hole 9 is longer as it is closer to the end side, The deformation suppressing function can be applied.

  5A to 5D show modifications of the core material 2 in the buckling restraint brace 1 described above. In the said embodiment, as the core material 2, as shown in FIG.5 (B), what formed the notch part 2a along a length direction on both sides of the length direction intermediate part of the elongate flat steel plate, and made it the narrow part 2A. Although used, the core material 2 as shown in FIG. 5A in which the narrow portion 2A is not formed may be used. Further, in an elongated flat steel plate that does not have the narrow width portion 2A, the core material 2 as shown in FIG. 5C in which bolt insertion holes 8 for bolting the restraint material 3 are arranged in two rows may be used. . Further, in the core material 2 in FIG. 5C, a reinforcing rib extending in the length direction as shown in FIG. 5D at an intermediate position in the width direction on one side opposite to the side in contact with the restraint material 3. 2b may be provided to have a T-shaped cross section. FIG. 5E shows a cross-sectional view taken along the line E-E in FIG.

  In FIG. 6, the side view of the buckling restraint brace 1 of the said embodiment and the buckling restraint braces 1A-1C of other each embodiment is shown. In the above embodiment, the web portion 3a of the restraining material 3 made of H-shaped steel is sandwiched between the pair of core materials 2 and 2 as shown in FIG. 6A, but as shown in FIG. 6B. The constraining material 3 may be a buckling constraining brace 1A having a structure composed of an H-shaped steel and two plates 3b and 3b joined between both ends of both flange portions of the H-shaped steel. In this case, it is desirable to dispose a plurality of the plates 3b dispersed in the longitudinal direction so that the core material 2 is visible from the outside. Further, as another embodiment, as shown in FIG. 6C, a buckling restrained brace 1 </ b> B may be used by using a constraining material 3 in which a pair of channel steels are joined back to back. Further, as shown in FIG. 6D, the restraining material 3 is composed of a pair of groove steels joined to each other on the back surface, and two plates 3c, 3c joined between both flange portions of both the groove steels. It is good also as the buckling restraint brace 1C of the structure which becomes. Also in this case, it is desirable to dispose a plurality of the plates 3c dispersed in the longitudinal direction so that the core material 2 is exposed from the outside.

1, 1A-1C ... Buckling restraint brace 2 ... Core material 3 ... Restraint material 4 ... Bolt 9 ... Bolt insertion hole

Claims (4)

  A pair of plate-like core members that are arranged in parallel with each other so that one side faces each other and both ends are connected to the building frame, and a restraining material that is sandwiched between these core members and restrains buckling of both core members. A buckling-restraining brace characterized in that the pair of core members are joined together with a plurality of bolts arranged at intervals in the longitudinal direction together with the restraining material.   The buckling restrained brace according to claim 1, wherein the core material is exposed so as to be visible from the outside.   The buckling restrained brace according to claim 1 or 2, wherein a pitch of the bolt is a constant pitch, and the pitch is matched to a buckling length of the core member.   The buckling restraint brace according to any one of claims 1 to 3, wherein a bolt insertion hole provided in the restraint member is a long hole that is long in a longitudinal direction of the core member.

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