JP6042108B2 - Buckling-restrained brace with fail-safe mechanism - Google Patents

Description

  The present invention relates to a buckling-restrained brace that is incorporated in a structure frame and absorbs vibration energy in the event of an earthquake, etc., and attenuates the vibration, and in particular, a failure that adds rigidity when plastic deformation, fracture, or crushing occurs. The present invention relates to a buckling-restrained brace with a fail-safe mechanism provided with a safe mechanism.

  As a buckling-restrained brace, a material in which the periphery of a core material is coated and stiffened with a steel plate, concrete, or the like is widely used in general. In addition, there is also one formed entirely of fiber reinforced concrete (for example, Patent Document 1). These conventional buckling-restrained braces were not equipped with a fail-safe mechanism when subjected to unexpected earthquake forces, even though they were sufficiently resistant to the assumed earthquake forces.

JP 2010-127002 A

  From the experience of huge earthquakes such as the Hyogoken-Nanbu Earthquake, the problems of conventional braces have become clear. For example, as shown in FIG. 10, when the multi-storey structure 30 is subjected to earthquake motion, if the brace 31 exceeds the allowable deformation ((A) in FIG. 10), the brace 31 cannot bear the yield strength (( B)), it was found that the layer collapsed ((C) in the figure).

  Such layer collapse is considered to occur for the following reasons. That is, the magnitude of the force acting on the structure 30 varies depending on the floor due to the period of the earthquake shaking. Therefore, the brace 31 on the floor that receives a large force with respect to the yield strength of the brace 31 yields first (the left diagram in FIG. 11). When the brace 31 yields, the rigidity decreases, and the floor easily deforms. Since damage concentrates on the floor with low rigidity, the deformation of the floor further proceeds (the right figure in FIG. 11), leading to the layer collapse.

  The object of the present invention is to provide a fail-safe mechanism that is effective in avoiding collapse of a building by avoiding the concentration of damage to only a part of the braces by providing a fail-safe mechanism when subjected to unexpected earthquake motion. It is to provide a buckled restrained brace.

The buckling restrained brace with a fail-safe mechanism of the present invention includes a core material and a restraining material disposed along both surfaces of the core material, and the core material concentrates buckling due to compressive force acting on both ends. A fail-safe mechanism is provided that has a weakly rigid portion and adds rigidity to the tensile force and compressive force of the core material when plastic deformation, breakage, or crushing occurs in the weakly rigid portion .

  The fail-safe mechanism may be activated when plastic deformation occurs in the weakly rigid portion, or the fail-safe mechanism may be activated when fracture or crushing occurs in the weakly rigid portion. In the former case, when the weakly rigid portion is plastically deformed by a tensile force or a compressive force, a fail-safe mechanism is activated to add rigidity against the tensile force or compressive force to the core material. Thereby, the rigidity of the entire core material is increased, and an increase in deformation of the core material is prevented. In the latter case, when the weakly rigid portion is broken or crushed by the tensile force or the compressive force, the fail-safe mechanism is activated to add rigidity to the core material to the tensile force or the compressive force. As a result, the core material gains new rigidity, and the subsequent deformation of the core material is suppressed, thereby preventing the building from collapsing.

In the present invention, the fail-safe mechanism is configured as shown below. That is, the fail-safe mechanism is opposed to one set or a plurality of sets of facing pieces that extend from both sides in the longitudinal direction of the weakly rigid portion of the core member and face each other via the first gap. A locked piece provided on one of the opposed pieces and a locked piece provided on the other opposed piece and opposed to the locked piece via a second gap. The first gap is sized such that when the weakly rigid portion of the core material undergoes plastic deformation or crushing in the compression direction, the opposed pieces facing each other come into contact with each other. When the plastic deformation or breakage in the pulling direction occurs in the weakly rigid portion of the material, the size is such that the locked piece and the locking piece are engaged.

With this configuration, when plastic deformation or crushing in the compression direction occurs in the weakly rigid portion of the core material, the opposing pieces that are opposed to each other come into contact with each other, thereby adding rigidity to the compression force. Further, when plastic deformation or breakage in the pulling direction occurs in the weakly rigid portion of the core material, the locking piece is locked to the locked piece, thereby adding rigidity to the tensile force.
The buckling restrained brace with a fail-safe mechanism of the present invention has the above-described configuration and includes any one of the following configurations.
For example, the entire core member including the weakly rigid portion, the opposing piece, and the locked piece, excluding the locking piece, is an integral member made of the same material.

In addition to this, for example, the weakly rigid portion of the core material is a portion between two slits provided in the core material along the length direction, and the opposing piece is more than the slit of the core material. May be a portion on the outer side in the width direction.
In this case, since the weakly rigid portion and the facing piece are arranged side by side on the same plane, the core material can have a simple configuration.

It is desirable that the first and second gaps are arranged at positions that can be seen from the outside of the restraint material.
If the first and second gaps can be visually observed from the outside of the restraint material, the degree of damage of the buckling restraint brace can be confirmed, and therefore whether or not the buckling restraint brace is replaced can be accurately determined.

  The buckling restrained brace with a fail-safe mechanism according to the present invention is a buckling restrained brace including a core material and a constraint material arranged along both surfaces of the core material. The core material has a compressive force acting on both ends. Since there is a weakly rigid part where buckling by It is effective in avoiding the collapse of the building by avoiding that the damage is concentrated only on the braces of the section.

It is a disassembled perspective view of the buckling restraint brace with a fail safe mechanism concerning one Embodiment of this invention. It is an assembly perspective view of the buckling restraint brace with the same fail-safe mechanism. It is sectional drawing of the XY plane of FIG. It is sectional drawing of the YZ plane of FIG. It is an exploded view of the fail safe mechanism of the buckling restraint brace. It is explanatory drawing which combined the figure which shows the change of the fail safe mechanism when compression force acts on the core material in an example of the buckling restraint brace with a fail safe mechanism, and the graph which shows the relationship between compression force and a deformation | transformation. It is explanatory drawing which combined the figure which shows the change of the fail safe mechanism when the tensile force acts on the core material in an example of the buckling restraint brace with a fail safe mechanism, and the graph which shows the relationship between a tensile force and a deformation | transformation. It is explanatory drawing which combined the figure which shows the change of the fail safe mechanism when the compressive force acts on the core material in the example from which the buckling restraint brace with a fail safe mechanism differs, and the graph which shows the relationship between compressive force and a deformation | transformation. A combination of a diagram showing the change in the fail-safe mechanism when a tensile force is applied to the buckling-restrained brace and a graph showing the relationship between the tensile force and deformation in different examples of buckling-restrained braces with a fail-safe mechanism It is explanatory drawing. It is explanatory drawing which shows the process of the layer destruction by an earthquake. It is a figure explaining the reason which damage concentrates on a part of layer.

  An embodiment of the present invention will be described with reference to FIGS. As shown in the exploded perspective view of FIG. 1, this buckling restraint brace 1 with a fail-safe mechanism includes a core member 2, a pair of restraint members 3 disposed along both surfaces of the core member 2, and a core member 2. And an unbond material 4 interposed between the restraining materials 3.

  The core material 2 is made of a steel material having a low yield point such as an SN material (rolled steel material for building structures) or a LYP material (very low yield point steel material), and is orthogonal to the alignment direction rather than the thickness in the alignment direction with the restraint material 3. It is in the shape of a long and narrow strip with a wide width in the direction to be. Both end portions 2a of the core material 2 are portions that become joints with steel frames such as columns and beams, and have a cross-shaped cross section having ribs 5 protruding vertically from the center positions in the width direction of both surfaces. A plurality of rows (two rows in the illustrated example) of bolt holes 6 are drilled in both end portions 2a of the core material 2. In the assembled state of the buckling restraint brace 1, both end portions 2 a of the core member 2 are exposed at both ends of the restraint member 3 as shown in FIG. 2.

  FIG. 4 is a diagram showing a main part of a buckling restrained brace with a fail-safe mechanism, and FIG. 5 is an exploded view of the core material of the main part. The core material 2 has a weakly rigid portion 7 whose rigidity is weakened by being narrower than the others at the center in the longitudinal direction. A pair of opposing pieces 9 and 10 are provided on both sides in the width direction of the weakly rigid portion 7 with the slit 8 interposed therebetween. The slit 8 may have a cut shape having no gap. The opposing pieces 9, 10 of each set extend from the portions on both sides in the length direction of the weakly rigid portion 7 and face each other via the first gap 11. The first gap 11 is sized such that when the weakly rigid portion 7 undergoes plastic deformation or crushing in the compression direction, the opposed pieces 9 and 10 that face each other come into contact with each other.

  A locked piece 12 that projects outward is formed at the tip of one opposing piece 9. A projecting portion 13 is formed on the tip of the other opposing piece 10 so as to project outward, and one end of each locking piece mounting member 14 is fixed to both the front and back surfaces of the projecting portion 13. The locking piece mounting member 14 is made of a strip-shaped steel plate. The overhanging portion 13 and the two locking piece mounting members 14 are fixed by a fixing tool including a bolt 15 and a nut 16 (FIG. 3) inserted into the bolt insertion holes 14a, 13a, and 14a. The fastener may be a rivet.

  The other ends of the two locking piece mounting members 14 extend toward the one opposing piece 9, and a locking piece 17 is fixed between the other ends. The locking piece 17 is made of a steel plate. The two locking piece mounting members 14 and the locking pieces 17 are fixed by a fixing tool including bolts 15 and nuts 16 (FIG. 3) inserted through the bolt insertion holes 14b, 17a, and 14b. The locked piece 12 and the locking piece 17 are opposed to each other via a second gap 18. The second gap 18 is sized such that when the weakly rigid portion 7 is plastically deformed or broken in the pulling direction, the locked piece 12 and the locking piece 17 are engaged.

  In order to engage the latched piece 12 and the latching piece 17 at an appropriate timing when the weakly rigid portion 7 is plastically deformed or broken in the tensile direction, the dimensional control of the second gap 18 is strictly performed. There is a need to do. In this embodiment, since the locking piece mounting member 14 is fixed to the overhanging portion 13 and the locking piece 17 is fixed to the locking piece mounting member 14 by bolt joining, adjustment at the installation site is possible. Yes, the locking piece 17 can be positioned with high accuracy, and the dimensional accuracy of the second gap 18 can be increased.

  The pair of opposing pieces 9 and 10, the locked piece 12 and the locking piece 17 are configured as a fail-safe mechanism 20 when an unexpected earthquake motion is applied. The fail-safe mechanism 20 is exposed to the outside of the restraining material 3 as shown in FIG. 2 when the buckling restraining brace 1 is assembled. Further, the first and second gaps 11 and 18 are arranged at positions that can be seen from the outside of the restraint material 3.

  As shown in FIG. 3, the constraining material 3 is obtained by filling a mortar 24 into a grooved steel material 23 opened on the core material 2 side. The grooved steel member 23 has a cross-sectional groove shape including a web portion 23a and both flange portions 23b and 23c rising vertically from both ends of the web portion 23a. One flange portion 23b is longer than the other flange portion 23c, and the longer flange portion 23b is in contact with the outer surface of the shorter flange portion 23c of the constraining material 3 facing the flange portion 23b. A notch 25 is formed in the longitudinal center portion of the longer flange portion 23 b, and the locked piece 12 and the overhanging portion 13 of the core material 2 pass through the notch 25 to the outside of the restraint material 3. Protruding to

  An unbond material 4 is attached to the surface of the mortar 24 facing the core material 2. The unbond material 4 is made of, for example, plate-like or sheet-like butyl rubber. The restraining material 3 and the unbonding material 4 are arranged so as to cover substantially the entire core material 2 excluding the tip portions of both end portions 2 a of the core material 2.

The buckling restraint brace 1 with the fail-safe mechanism having this configuration has two ways of setting the fail-safe mechanism 20.
The first setting method is to set the first gap 11 to such a size that the opposing pieces 9 and 10 come into contact with each other when the plastic deformation in the compression direction occurs in the weakly rigid portion 7 of the core material 2. The gap 18 is set to such a size that the locked piece 12 and the locking piece 17 are engaged when the plastic deformation in the pulling direction occurs in the weakly rigid portion 7. The operation of the buckling restrained brace 1 in this case will be described with reference to FIGS. The sizes of the first and second gaps 11 and 18 in the initial state in which neither the compressive force nor the tensile force is applied to the core material 2 are d and d ′, respectively (FIGS. 6A and 7A). .

  When a compressive force is applied to the core material 2, the weakly rigid portion 7 is contracted and deformed, so that the first gap 11 is narrowed (d−δ) and the second gap 18 is Spread (d ′ + δ). When the weakly rigid portion 7 is contracted and deformed by the length d, as shown in FIG. 6C, the size of the first gap 11 becomes zero, and the two pairs of opposing pieces 9 and 10 come into contact with each other. The safe mechanism 20 is activated. Thereby, as shown in FIG. 6D, the rigidity of the core material 2 is increased, and an increase in shrinkage deformation of the core material 2 is prevented.

  When a tensile force is applied to the core material 2, the weakly rigid portion 7 expands and deforms, whereby the first gap 11 is expanded (d + δ) and the second gap 18 is narrowed as shown in FIG. 7B ( d′−δ). When the weakly rigid portion 7 extends and deforms by the length d ′, the size of the second gap 18 becomes zero as shown in FIG. 7C, and the locked piece 12 and the locking piece 17 are locked to each other. As a result, the fail-safe mechanism 20 is activated. Thereby, as shown in FIG. 7D, the rigidity of the core material 2 is increased, and an increase in the elongation deformation of the core material 2 is prevented.

  As described above, when the fail-safe mechanism 20 is activated while the weakly rigid portion 7 of the core material 2 is plastically deformed, the fail-safe mechanism 20 acts as a brake against deformation, and a part of the plastically deformed portion is deformed. Concentration of damage on the buckling restrained brace 1 can be avoided.

  In the second setting method, the first gap 11 is set to a size such that the opposed pieces 9 and 10 come into contact with each other when the weakly rigid portion 7 of the core member 2 is crushed, and the second gap 18 is set. Is set to a size such that when the weakly rigid portion 7 is broken, the locked piece 12 and the locking piece 17 are engaged. The operation of the buckling restrained brace 1 in this case will be described with reference to FIGS. The sizes of the first and second gaps 11 and 18 in the initial state where neither the compressive force nor the tensile force is applied to the core material 2 are d and d ', respectively (FIGS. 8A and 9A). .

  When a compressive force is applied to the core material 2, the weakly rigid portion 7 is contracted and deformed, and as shown in FIG. 8B, the first gap 11 is narrowed (d−δ), and the second gap 18 is Spread (d ′ + δ). When the weakly rigid portion 7 is crushed, as shown in FIG. 8C, the size of the first gap 11 becomes zero, and the two pairs of opposing pieces 9 and 10 come into contact with each other, whereby the fail safe mechanism 20 is activated. To do. Thereby, as shown in FIG. 8D, the rigidity of the core material 2 is maintained, and an increase in shrinkage deformation of the core material 2 can be suppressed.

  When a tensile force is applied to the core material 2, the weakly rigid portion 7 expands and deforms, whereby the first gap 11 expands (d + δ) and the second gap 18 narrows as shown in FIG. 9B ( d′−δ). When the weakly rigid portion 7 breaks, as shown in FIG. 9C, the size of the second gap 18 becomes zero, and the locked piece 12 and the locking piece 17 are locked together, thereby fail-safe. The mechanism 20 is activated. Accordingly, as shown in FIG. 8D, the rigidity of the core material 2 is maintained, and an increase in the elongation deformation of the core material 2 can be suppressed.

  In this way, when the fail safe mechanism 20 is activated when the weakly rigid portion 7 of the core material 2 is crushed and broken, the fail safe mechanism 20 functions as a safety device and can prevent the building from collapsing.

  Since the opposing pieces 9 and 10, the locked pieces 12, and the locking pieces 17 that constitute the fail-safe mechanism 20 are exposed to the outside of the restraining material 3, the state can be easily confirmed. Can do. In particular, the first and second gaps 11 and 18 can be visually confirmed from the outside of the restraint material 3. Therefore, the degree of damage of the buckling restrained brace 1 can be understood well, and whether or not the buckling restrained brace 1 is replaced can be accurately determined.

In addition, although the weak rigidity part 7 of the said embodiment has weakened rigidity by making width narrower than others, even if it makes rigidity of the weak rigidity part 7 weak by making board thickness thinner than others. The rigidity of the weakly rigid portion 7 may be weakened by using a material having a lower rigidity than others.
Moreover, in the said embodiment, although the separate restraint material 3 was each provided in the both sides of the core material 2, it is good also as one restraint material with which the restraint material part of the both sides of the core material 2 was mutually integrated.

DESCRIPTION OF SYMBOLS 1 ... Buckling restraint brace 2 with a fail safe mechanism 2 ... Core material 3 ... Restraint material 7 ... Weak rigid part 8 ... Slit 9, 10 ... Opposing piece 11 ... 1st clearance 12 ... Locked piece 17 ... Locking piece 18 ... second gap 20 ... fail-safe mechanism

Claims (4)

In a buckling restrained brace comprising a core material and a constraint material arranged along both sides of the core material, the core material has a weakly rigid portion where buckling due to compressive force acting on both ends is concentrated, When plastic deformation or fracture or crushing occurs in this weakly rigid part, a fail-safe mechanism is provided to add rigidity to the tensile force and compressive force of the core material,
The fail-safe mechanism includes one or a plurality of opposing pieces that extend from both sides of the weakly rigid portion in the longitudinal direction of the core member and face each other via a first gap, and the opposing pieces that face each other. A locked piece provided on one of the opposing pieces, and a locking piece provided on the other opposing piece and opposed to the locked piece via a second gap,
The first gap is sized such that when the weakly rigid portion of the core material undergoes plastic deformation or crushing in the compression direction, the opposed pieces facing each other come into contact with each other.
The second gap is sized such that when the weakly rigid portion of the core material undergoes plastic deformation or breakage in the pulling direction, the locked piece and the locking piece engage with each other.
Including the weakly rigid portion, the opposing piece, and the locked piece, the entire core material excluding the locking piece is an integral member of the same material.
Buckling restraint brace with fail-safe mechanism. In a buckling restrained brace comprising a core material and a constraint material arranged along both sides of the core material, the core material has a weakly rigid portion where buckling due to compressive force acting on both ends is concentrated, When plastic deformation or fracture or crushing occurs in this weakly rigid part, a fail-safe mechanism is provided to add rigidity to the tensile force and compressive force of the core material,
The fail-safe mechanism includes one or a plurality of opposing pieces that extend from both sides of the weakly rigid portion in the longitudinal direction of the core member and face each other via a first gap, and the opposing pieces that face each other. A locked piece provided on one of the opposing pieces, and a locking piece provided on the other opposing piece and opposed to the locked piece via a second gap,
The first gap is sized such that when the weakly rigid portion of the core material undergoes plastic deformation or crushing in the compression direction, the opposed pieces facing each other come into contact with each other.
The second gap is sized such that when the weakly rigid portion of the core material undergoes plastic deformation or breakage in the pulling direction, the locked piece and the locking piece engage with each other.
The weakly rigid portion of the core material is a portion between two slits provided in the core material along the length direction, and the facing piece is a portion on the outer side in the width direction than the slit of the core material. A buckling-restrained brace with a fail-safe mechanism. In a buckling restrained brace comprising a core material and a constraint material arranged along both sides of the core material, the core material has a weakly rigid portion where buckling due to compressive force acting on both ends is concentrated, When plastic deformation or fracture or crushing occurs in this weakly rigid part, a fail-safe mechanism is provided to add rigidity to the tensile force and compressive force of the core material,
The fail-safe mechanism includes one or a plurality of opposing pieces that extend from both sides of the weakly rigid portion in the longitudinal direction of the core member and face each other via a first gap, and the opposing pieces that face each other. A locked piece provided on one of the opposing pieces, and a locking piece provided on the other opposing piece and opposed to the locked piece via a second gap,
The first gap is sized such that when the weakly rigid portion of the core material undergoes plastic deformation or crushing in the compression direction, the opposed pieces facing each other come into contact with each other.
The second gap is sized such that when the weakly rigid portion of the core material undergoes plastic deformation or breakage in the pulling direction, the locked piece and the locking piece engage with each other.
The said 1st and 2nd clearance gap is a buckling restraint brace with a fail safe mechanism arrange | positioned in the position which can be visually recognized from the outer side of the said restraint material. Oite to claim 2, wherein the first and second gap, the fail-safe mechanism with buckling restrained brace disposed on visual be positioned from the outside of the restraining member.

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