JP2014205969A - Buckling restraining brace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a buckling restraining brace capable of improving absorptivity of energy, without reducing bearing force in a restraining material, by restraining an increase in weight.SOLUTION: This buckling restraining brace 1 comprises a core material 2 composed of a band plate-like steel material and a pair of restraining materials 3 and 3 arranged along both surfaces of this core material 2. The core material 2 comprises an energy absorption part 2A of narrowing a width more than the other part between a length range sandwiched by the restraining materials 3 and 3. The restraining materials 3 are composed of a groove shape steel material 4 opening on the core material 2 side and concrete or mortar 5 filled in this groove shape steel material 4. A reinforcement steel material 6 is provided on both side edges in the width direction of including the length range where the energy absorption part 2A is provided in the core material 2 of the restraining materials 3, and is joined to the groove shape steel material 4.

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.

  An example of a conventional buckling restrained brace is shown in a sectional view in FIG. This buckling restraint brace is composed of a core member 22 and a restraint member 23 disposed along both surfaces of the core member 22. The concrete 25 is used as the restraining material 23, and the restraining force is enhanced by providing the channel steel material 24 on the outside thereof. The intermediate portion in the longitudinal direction of the core material 22 is a narrow width portion 22A in which notches 22a are formed on both sides. By concentrating strain on the narrow width portion 22A, yielding from an early stage of interlayer displacement such as during an earthquake And effectively absorb energy. Patent document 1 is one of the proposal examples which formed said notch part 22a.

Japanese Patent No. 04652322 JP 2010-265562 A

In the above conventional example, since the narrow portion 22A is provided in the core material 22, there is an advantage that energy can be effectively absorbed. However, in the case of a buckling restrained brace in which the thickness of the restraining material 23 is reduced as shown in FIG. 8, the grooved steel material 24 is caused by punching fracture of the concrete 25 of the restraining material 23 at the longitudinal intermediate portion that becomes the narrow width portion 22A. The web 24a (A portion in the figure) may be pushed out of the plane. Thereby, the restraint material 23 is destroyed.
Also, buckling-restrained braces having such a shape may exhibit a temporary decrease in yield strength. This is because the core member 22 has the narrow portion 22A, so that the force acting in the out-of-plane direction (indicated by an arrow F in FIG. 8) is applied to the concrete 25 in the cross section orthogonal to the axial direction of the buckling restraint brace. It cannot be transmitted to the flange 24b of the grooved steel member 24 via the cable, but is transmitted directly to the web 24a, and is therefore considered to be caused by receiving a local force on the web 24a. When the concrete 25 of the restraining material 23 is punched and broken, the performance of the concrete 25 as the restraining material 23 is impaired. Although the punching breakage can be prevented by increasing the thickness dimension of the restraining material 23, it is impossible to avoid an increase in weight due to the weight of the restraining material 23 and an increase in the amount of material used.

  As measures for solving the above problems, the present inventors proposed a buckling-restrained brace in which a certain amount (cross-sectional area) of deformed reinforcing bars is arranged and reinforced in the concrete 25 of the restraining material 23 (Japanese Patent Application No. 2012). 162568). However, there is another concern about the theory of its effect.

  An object of the present invention is to provide a buckling-restrained brace that can suppress an increase in weight and can improve energy absorption without causing a temporary decrease in yield strength of the restraining material.

The buckling-restraining brace of the present invention includes a core material made of a strip-shaped steel material and a pair of constraint materials arranged along both surfaces of the core material, and the core material is sandwiched between the constraint materials. A grooved steel member having an energy absorbing portion with a width narrower than that of the other part, and the constraining material opening on the core member side, and concrete filled in the grooved steel member In buckling restrained braces made of mortar,
A reinforcing steel material is provided on both side edges in the width direction including the length range in which the energy absorbing portion is provided on the core material of the restraint material, and is joined to the channel steel material.

  According to this configuration, since the energy absorbing portion having a width narrower than other portions is provided between the length ranges of the core material, the strain is concentrated on the energy absorbing portion, so that the interlayer displacement during an earthquake or the like can be reduced. It yields from an early stage and can effectively absorb energy. Reinforced steel material that extends in the length direction including the length range in which the energy absorption portion of the core material is provided on both side edges in the width direction of the grooved steel material of the constraining material has an energy absorption portion with a narrow width. Therefore, the fracture start location in the restraint material is reinforced, and the fracture length in the width direction of the channel steel web surface can be shortened. For this reason, even if the cross section of the restraint material is set thin for the purpose of suppressing the increase in weight, the restraint material sufficiently resists buckling, and an increase in punching strength and an increase in restraint force can be expected. That is, an increase in weight can be suppressed, a temporary decrease in the yield strength of the restraint material can be more reliably solved, and the energy absorbability can be improved.

In the present invention, the reinforcing steel material may be a square pipe shape, and may be welded to a flange and a web of the channel steel material. When the reinforcing steel material is in the form of a square pipe, the reinforcing effect is excellent, and the reinforcing steel material in the form of a square pipe is welded to both the flange and the web of the groove-shaped steel material, whereby the reinforcing steel material is reinforced more firmly.
In the buckling restrained brace of the present invention, the reinforcing steel material may be an angle shape, and may be welded to a flange and a web of the channel steel material. In this configuration, the amount of steel used for reinforcement can be reduced.

  The buckling-restraining brace of the present invention includes a core material made of a strip-shaped steel material and a pair of constraint materials arranged along both surfaces of the core material, and the core material is sandwiched between the constraint materials. A grooved steel member having an energy absorbing portion with a width narrower than that of the other part, and the constraining material opening on the core member side, and concrete filled in the grooved steel member In the buckling restrained brace made of mortar, since the reinforcing material is joined to the groove steel material by providing reinforcing steel materials on both side edges in the width direction including the length range in which the energy absorbing portion is provided in the core material, Energy absorption can be improved by suppressing an increase in weight and more reliably avoiding a temporary decline in the yield strength of the restraint material.

It is sectional drawing of the buckling restraint brace concerning 1st Embodiment of this invention. (A) is the IIa-IIa arrow sectional drawing in FIG. 1, (B) is the IIb-IIb arrow sectional drawing in FIG. It is sectional drawing of the buckling restraint brace concerning other embodiment of this invention. It is sectional drawing of the buckling restraint brace concerning further another embodiment of this invention. It is sectional drawing of the buckling restraint brace concerning further another embodiment of this invention. It is sectional drawing of the buckling restraint brace concerning further another embodiment of this invention. It is sectional drawing of the buckling restraint brace concerning further another embodiment of this invention. It is sectional drawing of a prior art example.

  A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a sectional view of the buckling restrained brace, and FIGS. 2A and 2B are a partially broken plan view and a partially broken side view, respectively. The buckling restraint brace 1 includes a core member 2 and a pair of restraint members 3 and 3 disposed along both surfaces of the core member 2. As shown in FIG. 2, the core material 2 is formed of an elongated flat steel plate, and an intermediate portion in the length direction is an energy absorbing portion 2A that is a narrow width portion having cutout portions 2a along the length direction on both sides. . The portion interposed between the restraining materials 3 and 3 of the core material 2 is composed of the energy absorbing portion 2A and wide portions 2C extending in the length direction at substantially the same width as the restraining material 3 on both sides thereof. Both end portions 2B of the core material 2 projecting from the restraining material 3 are portions that become joints with steel frames such as columns and beams, and a cross section having ribs 2b projecting vertically from the center positions in the width direction of both surfaces. It has a cross shape. A plurality of bolt holes (not shown) are formed in both end portions 2B of the core material 2. The restraining material 3 is disposed so as to cover substantially the entire portion excluding the tip portions of the both end portions 2B of the core material 2.

  As shown in FIG. 1, the pair of restraining members 3 and 3 are each composed of a channel steel material 4 having an opening on the core material 2 side, and concrete or mortar 5 filled in the channel steel material 4. An unbonded material 7 made of a viscoelastic material is interposed between the core material 2 and the restraining material 3. The pair of restraining members 3 and 3 are provided with reinforcing steel materials 6 on both side edges in the width direction in the length range in which the energy absorbing portion 2A of the core material 2 is provided, and these reinforcing steel materials 6 are groove-shaped. It is joined to the steel material 4. In this example, the reinforcing steel material 6 is formed of a square pipe shape, that is, one square pipe having a square cross section, and is welded to the flange 4 b and the web 4 a of the groove steel material 4. The length of one side of the cross section of the reinforcing steel material 6 made of this square pipe is equal to the thickness dimension of the concrete or the mortar 5 of the restraint material 3 and fits within the width dimension of the notch 2a in the core material 2. Is set. When the thickness dimension of the concrete or mortar 5 is hc and the length of the energy absorbing portion 2A in the core material 2 is L, the length of the reinforcing steel material 6 in this example is set to L + 2hc, and the length of the reinforcing steel material 6 Both end portions in the direction are arranged so as to protrude from the notch portion 2a of the core material 3 by hc in the length direction. In FIG. 2, the concrete or mortar 5 is omitted.

  According to the buckling restrained brace 1 having the above-described configuration, the intermediate portion in the length direction of the core material 2 is the energy absorbing portion 2A having a notch portion 2a along the length direction on both sides to become a narrow width portion. For this reason, the strain concentrates on the energy absorbing portion 2A, yielding from an early stage of interlayer displacement such as during an earthquake, and effective energy absorption can be performed. Although it has the energy absorption part 2A which became the narrow part by formation of the notch part 2a, it is the length by which the energy absorption part 2A of the core material 2 was provided in the both-sides edge of the width direction in the grooved steel material 4 of the restraint material 3 Since the reinforcing steel material 6 extending in the length direction over the entire range is joined, the fracture start location in the restraint material 3 is reinforced, and the concrete or the mortar 5 and the channel steel material 4 are prevented from peeling off. For this reason, even if the cross section of the constraining material 3 is set to be thin as shown in FIG. 1 for the purpose of suppressing an increase in weight, the constraining material 3 can sufficiently resist buckling, and an increase in punching strength and constraining force can be expected.

  Thus, according to the buckling restraint brace 1 having the above-described configuration, it is possible to suppress the increase in weight and improve the energy absorbability without reducing the yield strength of the restraint material 3. Further, the reinforcing steel material 6 in the shape of a square pipe having a square cross section is obtained by using the height of the reinforcing steel material 6 welded to the grooved steel material 4 when filling the grooved steel material 4 with concrete or mortar 5 as a guideline. Concrete or mortar 5 can be properly filled.

  FIG. 3 shows another embodiment of the present invention. In the embodiment shown in FIGS. 1 and 2, the buckling-restraining brace 1 of this embodiment is made of a square pipe having a rectangular cross section as the reinforcing steel material 6 instead of a square pipe having a square cross section. It arrange | positions so that the long side of the rectangular cross section may contact | connect the web 4a of the channel steel material 4. FIG. The short side dimension of the rectangular cross section of the reinforcing steel material 6 is shorter than the thickness dimension of the concrete or the mortar 5 in the channel steel material 4, and the long side dimension of the rectangular cross section is approximately within the width dimension of the notch 2 a in the core material 2. Set to dimensions. Other configurations and operational effects are the same as in the previous embodiment.

  FIG. 4 shows still another embodiment of the present invention. In the embodiment shown in FIGS. 1 and 2, the buckling-restraining brace 1 of this embodiment includes two reinforcing steel members 6 made of square pipes having a rectangular cross section instead of square pipes having a square cross section. In such a state that the long sides of the cross sections overlap each other, the short sides of each cross section are arranged so as to be in contact with the flange 4b of the channel steel material 4 and the long sides of the cross section are in contact with the web 4a of the channel steel material 4. The sum of the short side dimensions of the rectangular cross section of the two reinforced steel materials 6 that are stacked is equal to the thickness dimension of the concrete or mortar 5 of the restraint material 3, and the long side dimension of the rectangular cross section is the length of the notch 2 a of the core material 2. The dimension is set so as to be approximately within the width dimension. In the case of this example, since the two reinforcing steel materials 6 are provided so as to overlap each other, a higher reinforcing effect can be obtained. Other configurations and operational effects are the same as those of the embodiment shown in FIGS.

  FIG. 5 shows still another embodiment of the present invention. The buckling-restraining brace 1 of this embodiment is the same as that of the embodiment shown in FIG. 1 and FIG. In such a state that the long sides of the cross sections overlap, the short sides of each cross section are arranged so as to contact the web 4a of the channel steel material 4 and the long sides of the cross section contact the flange 4b of the channel steel 4. The long side dimension of the rectangular cross section of the two reinforced steel materials 6 that are stacked is equal to the thickness dimension of the concrete or mortar 5 of the restraint material 3, and the total short side dimension of the rectangular cross section is the notch portion 2 a of the core material 2. The dimension is set so as to be approximately within the width dimension. Also in this example, since the two reinforcing steel materials 6 are provided so as to overlap, a higher reinforcing effect can be obtained. Other configurations and operational effects are the same as those of the embodiment shown in FIGS.

  FIG. 6 shows still another embodiment of the present invention. In the embodiment shown in FIGS. 1 and 2, the buckling-restraining brace 1 of this embodiment is replaced by using one square pipe having a square cross section as the reinforcing steel material 6, and a square having a smaller cross section. Are arranged so that the cross-sectional outline is L-shaped, and the L-shaped corners are overlapped with the corners of the channel steel material 4. The length dimension of the two sides of the superposed reinforcing steel material 6 is set to a dimension that is equal to the thickness dimension of the concrete or the mortar 5 of the restraint material 3 and that is approximately within the width dimension of the notch 2a in the core material 2. Yes. In the case of this example, since the three reinforcing steel materials 6 are provided in an overlapping manner, a higher reinforcing effect can be obtained. Other configurations and operational effects are the same as those of the embodiment shown in FIGS.

  FIG. 7 shows still another embodiment of the present invention. The buckling restraint brace 1 of this embodiment is the same as that of the embodiment shown in FIG. 1 and FIG. Are arranged at the corners of the channel steel 4 such that the other side is parallel to the web 4a of the channel steel 4 and parallel to the flange 4b of the channel steel 4. The length dimension of one side of the angle material is set to a dimension that is equal to the thickness dimension of the concrete or the mortar 5 of the restraint material 3 and substantially fits within the width dimension of the notch 2a in the core material 2. In the case of this example, since the angle material is used, the amount of steel material used can be reduced as compared with the case of using the square pipe. Other configurations and operational effects are the same as those of the embodiment shown in FIGS.

DESCRIPTION OF SYMBOLS 1 ... Buckling restraint brace 2 ... Core material 2A ... Energy absorption part 2a ... Notch part 3 ... Restraint material 4 ... Channel steel 4a ... Web 4b ... Flange 5 ... Concrete or mortar 6 ... Reinforced steel

Claims (3)

A core material made of a strip-shaped steel material, and a pair of restraint materials arranged along both sides of the core material, the core material being placed between the length ranges sandwiched between the restraint materials In a buckling restrained brace made of a grooved steel material in which the width of the energy absorbing part is narrower than that of the part, and the constraining material is open to the core material side and concrete or mortar filled in the grooved steel material,
A buckling-restraining brace characterized in that a reinforcing steel material is provided on both side edges in the width direction including the length range in which the energy absorbing portion is provided on the core material, and is joined to the channel steel material.   The buckling restrained brace according to claim 1, wherein the reinforcing steel material is a square pipe shape and is welded to a flange and a web of the groove steel material.   The buckling constraining brace according to claim 1, wherein the reinforcing steel material has an angle shape and is welded to a flange and a web of the channel steel material.

Images