Brace structure

Abstract

To provide a simplified brace structure as suppressing buckling of a brace.SOLUTION: A brace structure is provided with an outer peripheral column-beam frame 20 having: a pair of columns 22, and an upper side large beam 24 and a lower side large beam 26 arranged over the pair of columns 22; an upper side frame surface outer beam 40 arranged outside of the frame surface of the outer peripheral column-beam frame 20 and opposite to the upper side large beam 24; and a pair of eccentric braces 50 of which an end part is connected on the pair of columns 22, respectively, and the other end is connected to a middle part 40M in a material axis direction of the upper side frame surface beam 40 with an interval in the material axis direction.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a brace structure.

Background Art

[0002] There is known a building construction method in which a protruding portion that jumps out from a building during construction is temporarily supported by a square rod (see, for example, Patent Document 1).

[0003] In addition, there is a vibration control structure including an oil damper obliquely installed between a column and a cantilever roof beam (see, for example, Patent Document 2).

[0004] In addition, there is a veranda structure having an inclined wall portion inclined in a direction away from the building (see, for example, Patent Document 3).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0006] By the way, a buckling-restrained brace in which a buckling-restraining stiffener is provided in a brace is known. In this buckling-restrained brace, buckling of the brace during an earthquake is suppressed, so that seismic performance can be ensured.

[0007] However, if a buckling-restraining stiffener is provided in the brace, the structure of the brace may become complicated.

[0008] In view of the above facts, an object of the present invention is to simplify the structure of a brace while suppressing buckling of the brace.

Means for Solving the Problems

[0009] The brace structure according to claim 1 includes a column-beam framework having a pair of columns and upper and lower girders installed on the pair of columns, an out-of-plane beam disposed outside the plane of the column-beam framework and facing the girders, and a pair of eccentric braces each having one end joined to the pair of columns respectively and the other end joined to an intermediate portion in the material axis direction of the out-of-plane beam with a space therebetween in the material axis direction.

[0010] According to the brace structure according to claim 1, the column-beam framework has a pair of columns and upper and lower girders installed on the pair of columns. An out-of-plane beam facing the girders is disposed outside the plane of the column-beam framework. The out-of-plane beam faces the girders of the column-beam framework.

[0011] Here, one end of each of the pair of eccentric braces is joined to the pair of columns respectively. Also, the other ends of the pair of eccentric braces are joined to an intermediate portion in the material axis direction of the out-of-plane beam with a space therebetween in the material axis direction.

[0012] Thereby, during an earthquake, axial forces (brace axial forces) act on the intermediate portion of the out-of-plane beam from the other ends of the pair of eccentric braces respectively. Due to the axial forces of the pair of eccentric braces, bending occurs in the intermediate portion of the out-of-plane beam. Therefore, before the pair of eccentric braces buckle, the intermediate portion of the out-of-plane beam can be yielded.

[0013] Therefore, in the present invention, while suppressing buckling of the pair of eccentric braces, the toughness of the column-beam framework can be enhanced. Further, in the present invention, the buckling supplementary stiffening members of the pair of eccentric braces can be omitted or reduced.

[0014] Thus, in the present invention, while suppressing buckling of the pair of eccentric braces, the structure of the pair of eccentric braces can be simplified.

[0015] Furthermore, in the present invention, the rigidity and load-bearing capacity of the column-beam framework can be adjusted by increasing or decreasing the cross-sectional area of the out-of-plane beam and the distance between the other ends of a pair of eccentric braces joined to the middle part of the out-of-plane beam.

[0016] In particular, the out-of-plane beam is arranged outside the out-of-plane of the column-beam framework. That is, since the out-of-plane beam is not installed on the column, long-term bending is small, and bending as a ramen framework does not occur during an earthquake. Therefore, the out-of-plane beam has a higher degree of freedom in designing cross-sectional performance compared to the large beam in the plane. Thus, by increasing or decreasing the cross-sectional performance of the out-of-plane beam, the rigidity and load-bearing capacity of the column-beam framework can be easily adjusted.

[0017] The brace structure according to claim 2 is the brace structure according to claim 1, and includes a small beam installed between the joint portion of the other end of the eccentric brace at the middle portion of the out-of-plane beam and the large beam.

[0018] According to the brace structure according to claim 2, the small beam is installed between the joint portion of the other end of the eccentric brace at the middle portion of the out-of-plane beam and the large beam. Thereby, during an earthquake, the horizontal component of the axial force acting from the other end of the eccentric brace to the middle portion of the out-of-plane beam is transmitted to the large beam through the small beam. Therefore, during an earthquake, the rotation (twisting) of the middle portion of the out-of-plane beam around the member axis is suppressed.

[0019] The brace structure according to claim 3 is the brace structure according to claim 1 or claim 2, and the out-of-plane beam is supported by a projecting beam that projects from each of the pair of columns.

[0020] According to the brace structure according to claim 3, the out-of-plane beam is supported by a projecting beam that projects from each of the pair of columns. Thereby, the out-of-plane beam can be easily installed outside the out-of-plane of the column-beam framework.

Advantages of the Invention

[0021] As described above, according to the present invention, while suppressing buckling of the brace, the structure of the brace can be simplified.

Brief Description of the Drawings

[0022]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0023] Hereinafter, an embodiment will be described with reference to the drawings.

[0024] (Structure) In FIGS. 1, 2, and 3, the outer peripheral part of the structure 10 to which the brace structure according to this embodiment is applied is shown. The structure 10 is, for example, composed of a plurality of layers. This structure 10 includes an outer peripheral column-beam framework 20, a pair of upper outrigger beams 30, a pair of lower outrigger beams 32, an upper out-of-plane beam 40, a lower out-of-plane beam 42, and a pair of eccentric braces 50.

[0025] Note that the outer peripheral column-beam framework 20 is an example of a column-beam framework. Also, the upper out-of-plane beam 40 is an example of an out-of-plane beam. Also, the upper outrigger beam 30 is an example of an outrigger beam.

[0026] (Outer Peripheral Column-Beam Framework) As shown in FIG. 1, the outer peripheral column-beam framework 20 is arranged along the outer peripheral part (arrow X direction) of the structure 10. Also, the outer peripheral column-beam framework 20 has a ramen framework having a pair of columns 22 and upper girders 24 and lower girders 26 installed on the pair of columns 22. Note that the upper girders 24 and the lower girders 26 are examples of upper and lower girders.

[0027] The pair of columns 22 are, as an example, steel frame columns formed of steel pipe steel. Further, the pair of columns 22 are arranged at intervals. An upper girder 24 and a lower girder 26 are installed on this pair of columns 22.

[0028] Note that the column 22 is not limited to steel pipe steel and may be formed of, for example, H-shaped steel. Further, the column 22 is not limited to a steel frame structure (steel frame column) and may be, for example, a reinforced concrete structure, a steel frame reinforced concrete structure, a CFT structure, etc.

[0029] The upper girder 24 and the lower girder 26 are, as an example, steel frame girders formed of H-shaped steel. The upper girder 24 and the lower girder 26 are installed on the pair of columns 22 in a state of being spaced apart in the vertical direction.

[0030] Note that the upper girder 24 and the lower girder 26 are not limited to a steel frame structure (steel frame girder) and may be, for example, a reinforced concrete structure, a steel frame reinforced concrete structure, etc.

[0031] (Upper cantilever beam, lower cantilever beam) As shown in FIGS. 1 and 4, the pair of upper cantilever beams 30 are, as an example, steel frame cantilever beams formed of H-shaped steel. Further, the pair of upper cantilever beams 30 each jump outwards from the joint portion 22S1 between the pair of columns 22 and the upper girder 24 and are supported in a cantilever state by the outer peripheral column beam structure 20. An upper out-of-plane beam 40 is provided at the tip of these upper cantilever beams 30.

[0032] The pair of lower cantilever beams 32 are, as an example, steel frame cantilever beams formed of H-shaped steel. Further, the pair of lower cantilever beams 32 each jump outwards from the joint portion 22S2 between the pair of columns 22 and the lower girder 26 and are supported in a cantilever state by the outer peripheral column beam structure 20. A lower out-of-plane beam 42 is provided at the tip of these lower cantilever beams 32.

[0033] Note that the upper jump-out beam 30 and the lower jump-out beam 32 are not limited to a steel frame structure (steel main beam), and may be, for example, a reinforced concrete structure, a steel-reinforced concrete structure, or the like.

[0034] (Upper out-of-plane beam, lower out-of-plane beam) As shown in FIGS. 1, 2, and 4, the upper out-of-plane beam 40 and the lower out-of-plane beam 42 are, as an example, steel out-of-plane beams formed of H-shaped steel. Further, the upper out-of-plane beam 40 and the lower out-of-plane beam 42 are disposed outside (outdoor side) with respect to the outer peripheral column-beam framework 20. That is, the upper out-of-plane beam 40 and the lower out-of-plane beam 42 are disposed outside the plane of the outer peripheral column-beam framework 20.

[0035] The upper out-of-plane beam 40 and the lower out-of-plane beam 42 are arranged at intervals in the vertical direction so as to face the upper main beam 24 and the lower main beam 26, respectively. Further, the upper out-of-plane beam 40 and the lower out-of-plane beam 42 are arranged to face each other in the vertical direction.

[0036] The upper out-of-plane beam 40 is installed at the tip of adjacent upper jump-out beams 30 and is supported by these upper jump-out beams 30. That is, the upper out-of-plane beam 40 is not installed on the column. Further, a planar structure is constituted by the upper main beam 24, the upper jump-out beam 30, and the upper out-of-plane beam 40. For example, a slab (not shown) or the like is provided in this planar structure.

[0037] Note that the planar structure constituted by the upper main beam 24, the upper jump-out beam 30, and the upper out-of-plane beam 40 may be reinforced by a horizontal brace, a shear panel such as a steel plate, or the like.

[0038] The lower out-of-plane beam 42 is installed at the tip of adjacent lower jump-out beams 32 and is supported by these lower jump-out beams 32. That is, the lower out-of-plane beam 42 is not installed on the column. Further, a planar structure is constituted by the lower main beam 26, the lower jump-out beam 32, and the lower out-of-plane beam 42. For example, a slab (not shown) or the like is provided in this planar structure.

[0039] Note that the planar framework composed of the lower main girder 26, the lower jump-out beam 32, and the lower out-of-plane beam 42 may be reinforced by horizontal braces, shear panels such as steel plates, or the like.

[0040] In addition, the upper out-of-plane beam 40 is a continuous beam that is not segmented at the tip of the upper jump-out beam 30. Similarly, the lower out-of-plane beam 42 is a continuous beam that is not segmented at the tip of the lower jump-out beam 32.

[0041] In this embodiment, for convenience of explanation, the part of the upper out-of-plane beam 40 extending across the tips of adjacent upper jump-out beams 30 is regarded as one upper out-of-plane beam 40. Among this one upper out-of-plane beam 40, the part on the upper jump-out beam 30 side is defined as the end portion 40E, and the part connecting the end portions 40E is defined as the intermediate portion 40M.

[0042] Similarly, the part of the lower out-of-plane beam 42 extending across the tips of adjacent lower jump-out beams 32 is regarded as one lower out-of-plane beam 42. Among this one lower out-of-plane beam 42, the part on the lower jump-out beam 32 side is defined as the end portion 42E, and the part connecting the end portions 42E is defined as the intermediate portion 42M.

[0043] Here, the out-of-plane beams (upper out-of-plane beam 40, lower out-of-plane beam 42) in this embodiment mean beams that are not installed on columns, that is, beams that are not directly joined to columns. This out-of-plane beam may or may not bear seismic forces.

[0044] Note that the upper out-of-plane beam 40 and the lower out-of-plane beam 42 are not limited to steel frame structures (steel girders), and may be, for example, reinforced concrete structures, steel-reinforced concrete structures, or the like.

[0045] (Eccentric brace) As shown in FIG. 1, as an example, the pair of eccentric braces 50 are steel frame braces formed of circular steel pipes. The pair of eccentric braces 50 are obliquely installed between the columns 22 of the outer peripheral column-beam framework 20 and the upper out-of-plane beam 40. That is, the pair of eccentric braces 50 are three-dimensionally inclined.

[0046] Note that the eccentric brace 50 is not limited to a round steel pipe, and may be, for example, a steel pipe such as a square steel pipe or a shaped steel such as an H-shaped steel. Further, the eccentric brace 50 is not limited to a steel frame structure (steel frame brace), and may be, for example, a reinforced concrete structure or a steel frame reinforced concrete structure.

[0047] As shown in FIG. 2, the pair of eccentric braces 50 are eccentric K-shaped braces arranged in a K shape when viewed from the out-of-plane direction of the outer peripheral column-beam frame 20. Specifically, the lower ends (one ends) 50L of the pair of eccentric braces 50 are respectively joined to the joint portions 22S2 (see FIG. 1) between the column 22 and the lower large beam 26.

[0048] On the other hand, the upper ends (the other ends) 50U of the pair of eccentric braces 50 are respectively joined to the middle portions 40M in the material axis direction (arrow X direction) of the upper out-of-plane beam 40. Further, the upper ends 50U of the pair of eccentric braces 50 are arranged at intervals in the material axis direction of the upper out-of-plane beam 40.

[0049] Thereby, as shown in the schematic diagram of FIG. 5, at the time of an earthquake, a bending (bending moment M) is generated in the middle portion 40M by the axial force (brace axial force) acting from the upper end portion 50U of the eccentric brace 50 to the middle portion 40M of the upper out-of-plane beam 40.

[0050] (Small beam) As shown in FIGS. 2 and 4, the small beam 60 is, as an example, a steel frame small beam formed of an H-shaped steel. This small beam 60 is respectively installed on the upper large beam 24 and the joint portion 40S between the pair of eccentric braces 50 in the upper out-of-plane beam 40. By these small beams 60, as indicated by arrow a in FIG. 4, the rotation of the upper out-of-plane beam 40 around the material axis at the time of an earthquake is suppressed.

[0051] Note that the small beam 60 is not limited to an H-shaped steel, and may be, for example, a C-shaped steel or an L-shaped steel. Further, the small beam 60 is not limited to a steel frame structure (steel frame small beam), and may be, for example, a reinforced concrete structure or a steel frame reinforced concrete structure.

[0052] (Function) Next, the function of this embodiment will be described.

[0053] As shown in FIG. 1, according to this embodiment, the outer peripheral column-beam structure 20 has a pair of columns 22, an upper main beam 24 and a lower main beam 26 erected on the pair of columns 22. Outside the cross-section of this outer peripheral column-beam structure 20, an upper out-of-plane beam 40 is arranged. The upper out-of-plane beam 40 faces the upper main beam 24 of the outer peripheral column-beam structure 20.

[0054] Here, the lower ends (one ends) 50L of the pair of eccentric braces 50 are respectively joined to the pair of columns 22. Further, the upper ends 50U (the other ends) of the pair of eccentric braces 50 are joined to the middle part 40M in the material axis direction of the upper out-of-plane beam 40 with a space in the material axis direction.

[0055] As a result, as shown in FIG. 5, during an earthquake, axial forces (brace axial forces) act from the upper ends 50U of the pair of eccentric braces 50 to the middle part 40M of the upper out-of-plane beam 40 respectively. Due to the axial forces of this pair of eccentric braces 50, bending (bending moment M) occurs in the middle part 40M of the upper out-of-plane beam 40. Therefore, before the pair of eccentric braces 50 buckles, the middle part 40M of the upper out-of-plane beam 40 can be yielded.

[0056] Therefore, in this embodiment, while suppressing the buckling of the pair of eccentric braces 50, the toughness of the outer peripheral column-beam structure 20 can be enhanced. Further, in this embodiment, the buckling supplementary stiffening members of the pair of eccentric braces 50 can be omitted or reduced.

[0057] Thus, in this embodiment, while suppressing the buckling of the pair of eccentric braces 50, the structure of the pair of eccentric braces 50 can be simplified.

[0058] Furthermore, in this embodiment, by increasing or decreasing the cross-sectional area of the upper out-of-plane beam 40 and the interval between the upper ends 50U of the pair of eccentric braces 50 joined to the middle part 40M of the upper out-of-plane beam 40, the rigidity and load-bearing capacity of the outer peripheral column-beam structure 20 can be adjusted.

[0059] In particular, the upper out-of-plane beam 40 is disposed outside the plane of the outer peripheral column-beam framework 20. That is, since the upper out-of-plane beam 40 is not erected on the column 22, the long-term bending is small, and bending as a ramen structure does not occur during an earthquake. Therefore, the upper out-of-plane beam 40 has a higher degree of freedom in the design of the cross-sectional performance compared to the upper main beam 24 within the plane. Therefore, by increasing or decreasing the cross-sectional performance of the upper out-of-plane beam 40, the rigidity and load-bearing capacity of the outer peripheral column-beam framework 20 can be easily adjusted.

[0060] Also, as shown in FIG. 4, the small beam 60 is erected on the joint portion 40S with the upper end portion 50U of the eccentric brace 50 in the middle portion 40M of the upper out-of-plane beam 40 and the upper main beam 24. Thereby, during an earthquake, the horizontal component of the axial force acting from the upper end portion 50U of the eccentric brace 50 to the middle portion 40M of the upper out-of-plane beam 40 is transmitted to the upper main beam 24 via the small beam 60. Therefore, during an earthquake, the rotation (twisting) of the middle portion 40M of the upper out-of-plane beam 40 around the material axis as indicated by the arrow a is suppressed.

[0061] Furthermore, the upper out-of-plane beam 40 is supported by the upper projecting beams 30 that project from the pair of columns 22 respectively. Thereby, the upper out-of-plane beam 40 can be easily installed outside the plane of the outer peripheral column-beam framework 20.

[0062] Also, the lower end portions 50L of the pair of eccentric braces 50 are joined to the joint portion 22S2 between the pair of columns 22 and the lower main beam 26. Thereby, the axial forces of the pair of eccentric braces 50 can be easily processed at the joint portion 22S2 between the high-rigidity columns 22 and the lower main beam 26.

[0063] (Modification example) Next, a modification example of the above embodiment will be described.

[0064] In the above-described embodiment, a secondary beam 60 is installed between the joint portion 40S of the intermediate portion 40M of the upper lateral surface external beam 40 and the upper end portion 50U of the eccentric brace 50, and the upper main beam 24. However, the secondary beam 60 may be provided as necessary and can be omitted as appropriate.

[0065] Also, in the above-described embodiment, the lower end portions 50L of the pair of eccentric braces 50 are joined to the joint portion 22S2 between the column 22 and the lower main beam 26. However, the lower end portions 50L of the pair of eccentric braces 50 are not limited to the joint portion 22S2 of the column 22 and may be joined to other portions of the column 22.

[0066] Also, in the above-described embodiment, the lower end portions 50L of the pair of eccentric braces 50 are joined to the joint portion 22S2 between the column 22 and the lower main beam 26, and the upper end portions 50U of the pair of eccentric braces 50 are joined to the intermediate portion 40M of the upper lateral surface external beam 40. However, conversely, the upper end portions 50U of the pair of eccentric braces 50 may be joined to the joint portion 22S1 between the column 22 and the upper main beam 24, and the lower end portions 50L of the pair of eccentric braces 50 may be joined to the intermediate portion 42M of the lower lateral surface external beam 42.

[0067] Also, in the above-described embodiment, the column-beam structure to which the pair of eccentric braces 50 are joined is the outer peripheral column-beam structure 20. However, the column-beam structure is not limited to the outer peripheral column-beam structure 20 provided at the outer periphery of the structure 10, and may be, for example, a column-beam structure provided inside the structure 10. In this case, the lateral surface external beam is installed (supported) on a main beam that is orthogonal to the column-beam structure, for example, outside the lateral surface of the column-beam structure.

[0068] As described above, one embodiment of the present invention has been described. However, the present invention is not limited to such an embodiment, and one embodiment and various modified examples may be appropriately combined and used, and it goes without saying that the present invention can be implemented in various modes without departing from the gist of the present invention.

Explanation of Reference Numerals

[0069] 20 Outer peripheral column-beam structure (column-beam structure) 22 Column 24 Upper main beam (main beam) 26 Lower side girder (girder) 30 Upper side projecting beam (projecting beam) 40 Upper side out-of-plane beam (out-of-plane beam) 40M Middle part (middle part in the material axis direction of the out-of-plane beam) 40S Joint part (joint part with the other end of the eccentric brace in the middle part in the material axis direction of the out-of-plane beam) 50 Eccentric brace 50L Lower end (one end) 50U Upper end (the other end) 60 Small beam

Claims

1. A column-beam structure having a pair of columns and upper and lower girders erected on the pair of columns; An out-of-plane beam disposed outside the cross-section of the column-beam structure and facing the girder; A pair of eccentric braces, one end of each being joined to the pair of columns respectively, and the other end being joined to an intermediate portion in the material axis direction of the out-of-plane beam with a space therebetween in the material axis direction; A brace structure comprising the above.

2. The brace structure according to claim 1, further comprising a secondary beam erected between a joint portion of the other end of the eccentric brace and the intermediate portion of the out-of-plane beam and the girder. The brace structure according to claim 1.

3. The out-of-plane beam is supported by a projecting beam projecting from each of the pair of columns. The brace structure according to claim 1 or claim 2.

Images