Building

Abstract

To provide a building that can improve the degree of freedom in design when arranging buckling restraint braces.SOLUTION: Provided is a building 100A with a plurality of buckling restraint braces 1. The buckling restraint braces 1 each include a core material and a restraint material that restrains the buckling of the core material, and the plurality of buckling restraint braces 1 include a first buckling restraint brace 1A that has a first core material made of a first steel type as its core material, and a second buckling restraint brace 1B that has a second core material made of a second steel type that has a higher yield strength than the first steel type as its core material.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to buildings. [Background technology]

[0002] Buckling-restrained braces have traditionally been used as reinforcing materials for buildings. In buckling-restrained braces, the core material that receives axial force is restrained from the outer periphery by restraining materials and filler materials, allowing the core material to undergo plastic deformation while preventing deformation and buckling in any direction other than the longitudinal direction. The use of buckling-restrained braces improves the earthquake resistance and vibration control performance of buildings. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-25260 Summary of the Invention [Problem to be solved by the invention]

[0004] Conventionally, the core materials of multiple buckling restrained braces placed in a building have all been made of the same type of steel. When attempting to design a building using only buckling restrained braces with the same core steel type, it can be difficult to adjust the rigidity balance of the building (frame and buckling restrained braces), making it difficult to ensure design freedom.

[0005] Specifically, for example, due to functional or design requirements of a building, the placement of buckling-restrained braces may be offset in plan view. Furthermore, this offset may result in a misalignment between the building's center of rigidity in plan view and its center of gravity in plan view. In such cases, when vibrations due to earthquakes or other factors are input to the building, the building experiences torsional deformation around the center of rigidity. Because the amount of deformation increases with distance from the center of rigidity, a large force acts on buckling-restrained braces located farther from the center of rigidity. Therefore, if all buckling-restrained braces located in a building are identical, buckling-restrained braces located farther from the center of rigidity will yield prematurely. To prevent this premature yielding, it is possible to increase the cross-sectional area of ​​the core material of buckling-restrained braces located farther from the center of rigidity to improve their axial strength. However, increasing the cross-sectional area of ​​the core material also increases the rigidity of the buckling-restrained brace in proportion to the cross-sectional area. Because loads are concentrated on buckling-restrained braces with increased rigidity, even larger forces act on the buckling-restrained braces. This creates a vicious cycle in which the cross-sectional area of ​​the core material of the buckling-restrained brace is further increased in order to resist this force, resulting in the problem of the cross-sectional area of ​​the buckling-restrained brace increasing more than necessary. Furthermore, as mentioned above, the stiffness of the buckling-restrained brace increases in proportion to the increase in the cross-sectional area of ​​the core material, making it difficult to adjust the stiffness balance of the building (frame and buckling-restrained brace) and ensuring design freedom. Furthermore, because the force acting on the buckling-restrained brace is increasing, a large pull-out force acts on the foundation located directly below the buckling-restrained brace, further complicating design.

[0006] Furthermore, for example, a building may have a high floor (hereinafter referred to as the "open area floor") where an open area such as an entrance is formed. Because the columns arranged in the open area connect the open area floor and the floors above, it is difficult to ensure sufficient rigidity of the open area floor solely through frame design, such as adjusting the column thickness. While thickening the columns to ensure the rigidity of the open area floor is an option, the column thickness must be uniformly adjusted across the entire column between the open area floor and the floors above. Therefore, if the columns on the open area floor are made thicker, the columns on the floors above will also become thicker, disrupting the rigidity balance of the building. Therefore, there is a limit to ensuring the rigidity of the open area by adjusting the column thickness. This results in a difference in rigidity between the open area floor and the floors above, and buckling restraint braces are installed on the open area floor to reinforce the open area floor. If buckling-restrained braces with the same core steel type as those used on other floors are used on the open-area floors, the cross-sectional area of ​​the core material must be increased to ensure the required axial strength of the buckling-restrained braces on the open-area floors, resulting in increased stiffness of the buckling-restrained braces. As a result, loads may be concentrated on the buckling-restrained braces installed on the open-area floors, potentially causing them to yield earlier than the buckling-restrained braces installed on other floors. To prevent this premature yielding, attempts to increase the axial strength of the buckling-restrained braces installed on the open-area floors would further increase the cross-sectional area of ​​the core material of the buckling-restrained braces, resulting in an unnecessarily large cross-sectional area of ​​the buckling-restrained braces. On the other hand, to prevent load concentration on the buckling-restrained braces on the open-area floors, it is possible to reduce the cross-sectional area of ​​the core material to reduce the stiffness of the buckling-restrained braces and transfer the load to the frame. However, this would also reduce the axial strength of the buckling-restrained braces. Thus, using only buckling-restrained braces with the same core steel type makes it difficult to design a building.

[0007] The present disclosure has been made in consideration of the above-mentioned circumstances, and aims to provide a building that allows for improved design freedom when placing buckling restraint braces. [Means for solving the problem]

[0008] A building according to one embodiment of the present disclosure is a building provided with a plurality of buckling restraint braces, each of which comprises a core material and a restraint material that restrains the buckling of the core material, and the plurality of buckling restraint braces include a first buckling restraint brace having a first core material made of a first steel type as the core material, and a second buckling restraint brace having a second core material made of a second steel type as the core material, the second steel type having a higher yield strength than the first steel type. [Effects of the Invention]

[0009] According to the present disclosure, it is possible to provide a building that allows for improved design freedom when placing buckling restraint braces. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a front view of a building according to a first embodiment. [Figure 2] FIG. 2 is a cross-sectional view of the buckling restrained brace according to the first embodiment. [Figure 3] FIG. 2 is a schematic plan view showing an example of the arrangement of buckling restraint braces in the building according to the first embodiment. [Figure 4] FIG. 10 is a schematic plan view showing another example of the arrangement of buckling restraint braces in the building according to the first embodiment. [Figure 5] FIG. 10 is a schematic plan view showing another example of the arrangement of buckling restraint braces in the building according to the first embodiment. [Figure 6] FIG. 10 is a front view of the building according to the second embodiment. [Figure 7] FIG. 10 is a front view of the building according to the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] First Embodiment Hereinafter, a building 100A according to a first embodiment of the present disclosure will be described with reference to FIGS.

[0012] The building 100A has multiple floors. The building 100A is a frame structure equipped with multiple beams 101 extending horizontally and multiple columns 102 extending vertically. The columns 102 are provided between the beams 101 on the upper floors and the beams 101 on the lower floors of the building 100A.

[0013] The building 100A is provided with multiple buckling restrained braces 1. The buckling restrained braces 1 are used to reinforce the building 100A. The buckling restrained braces 1 are attached diagonally to a frame made up of two columns 102 spaced apart horizontally from each other and two beams 101 connecting these columns 102 at the top and bottom. More specifically, the buckling restrained braces 1 are installed diagonally between an upper connecting member (not shown) fixed to the intersection of the upper beam 101 and one of the columns 102, and a lower connecting member (not shown) fixed to the intersection of the lower beam 101 and the other column 102.

[0014] As shown in FIG. 2, the buckling restrained brace 1 includes a core material 10, a secondary core material 20, a restraining material 30, a filling material 31, and an unbonded material 32.

[0015] The core material 10 is a plate-shaped member made of steel plate. The core material 10 has a narrow width portion 11 and a wide width portion 12. The narrow width portion 11 is located at the longitudinal center of the core material 10. The wide width portions 12 are located at both longitudinal ends of the core material 10. The plate width of the wide width portion 12 is larger than the plate width of the narrow width portion 11. The longitudinal center of the core material 10 is the narrow width portion 11, and the longitudinal ends are the wide width portions 12, so that the longitudinal center of the core material 10 (i.e., the narrow width portion 11) becomes a region that is easily plasticized, and the plasticized region is limited to this center. The longitudinal ends of the core material 10 (i.e., the wide width portions 12) maintain elastic regions.

[0016] The secondary core material 20 is a plate-shaped member made of steel plate. The secondary core material 20 is provided at each end of the core material 10 (i.e., the wide portion 12). The secondary core material 20 is provided on both sides of the core material 10 facing the plate width direction. The core material 10 and the secondary core material 20 have a cross-shaped cross section. The secondary core material 20 reinforces the end of the core material 10 and prevents the core material 10 from bending in the plate thickness direction.

[0017] The secondary core material 20 and the wide portion 12 each have a bolt hole 15. The buckling restrained brace 1 is attached to the frame of the building 100A by bolts (not shown) inserted into the bolt holes 15.

[0018] The restraining member 30 is tubular. For example, the restraining member 30 is a square or cylindrical steel pipe. The restraining member 30 covers the outer periphery of the core material 10. The restraining member 30 houses the core material 10 with both ends (wide portions 12) of the core material 10 protruding.

[0019] The filler 31 is filled inside the restraining member 30. The filler 31 restrains the buckling of the core member 10. For example, the filler 31 is made of concrete or mortar. The unbonding material 32 covers the portions of the core member 10 and the secondary core member 20 that are positioned inside the restraining member 30. The unbonding material 32 prevents the core member 10 and the secondary core member 20 from adhering to the filler 31. The unbonding material 32 allows the core member 10 and the secondary core member 20 to move relative to the filler 31. By providing the unbonding material 32, the filler 31 holds the core member 10 so that it can move relative to the restraining member 30 in the longitudinal direction, preventing the axial force of the core member 10 from being transmitted to the restraining member 30. The restraining member 30 and the filler 31 restrict deformation of the core member 10 in directions other than the longitudinal direction.

[0020] In this embodiment, the multiple buckling-restrained braces 1 include a first buckling-restrained brace 1A and a second buckling-restrained brace 1B. The first buckling-restrained brace 1A includes a first core material 10A made of a first steel type as the core material 10. The second buckling-restrained brace 1B includes a second core material 10B made of a second steel type that has a higher yield strength than the first steel type as the core material 10. For example, the yield strength of the first steel type that constitutes the first core material 10A is 205 to 385 N / mm 2 The yield strength of the second steel type constituting the second core material 10B is 325 to 440 N / mm 2 For example, SN490B can be used as the first steel type constituting first core material 10A, and in this case, BT-HT385B can be used as the second steel type constituting second core material 10B.

[0021] The first buckling restrained brace 1A and the second buckling restrained brace 1B have the same configuration except for the steel type of the core material 10. For example, the shapes of each component of the first buckling restrained brace 1A and the second buckling restrained brace 1B are the same. More specifically, the first core material 10A of the first buckling restrained brace 1A and the second core material 10B of the second buckling restrained brace 1B have the same cross-sectional area and cross-sectional shape of the cross section perpendicular to the longitudinal direction. This results in the first buckling restrained brace 1A and the second buckling restrained brace 1B having the same axial rigidity. The axial rigidity of the first buckling restrained brace 1A and the second buckling restrained brace 1B being substantially the same. The axial rigidity of the first buckling restrained brace 1A and the second buckling restrained brace 1B is designed taking into consideration the balance with the frame rigidity of the building 100A. The axial stiffness of the first buckling restrained brace 1A and the axial stiffness of the second buckling restrained brace 1B do not have to be the same.

[0022] As shown in FIG. 1, building 100A has a mixed floor F11 and a non-mixed floor F12. On mixed floor F11, both a first buckling restrained brace 1A and a second buckling restrained brace 1B are arranged as buckling restrained braces 1. On non-mixed floor F12, only the first buckling restrained brace 1A or only the second buckling restrained brace 1B is arranged as buckling restrained braces 1. That is, in this embodiment, the first buckling restrained brace 1A and the second buckling restrained brace 1B are arranged on the same floor (mixed floor F11). Note that a floor refers to a space separated by a floor and a ceiling. That is, on mixed floor F11 of building 100A, the first buckling restrained brace 1A and the second buckling restrained brace 1B are arranged at the same height.

[0023] The placement of the buckling restraint braces 1 on the mixed floor F11 will now be described. Figure 3 is a schematic plan view showing an example of the placement of the buckling restraint braces 1 on the mixed floor F11. As shown in Figure 3, a direction perpendicular to the vertical direction is referred to as the X direction, and a direction perpendicular to the vertical and X directions is referred to as the Y direction. In the following explanation, the placement of the buckling restraint braces 1 in the X direction will be described, but the placement of the buckling restraint braces 1 in the Y direction can also be designed using a similar method.

[0024] As shown in Fig. 3, on the mixed floor F11, a plurality of beams 101 are arranged in a lattice pattern extending in the X and Y directions. Columns 102 are also arranged at the intersections of the lattice pattern.

[0025] On the mixed floor F11, multiple buckling restrained braces 1 are distributed at different positions in a plan view. On the mixed floor F11, the placement of the buckling restrained braces 1 is uneven in plan view, with a first placement region R1 where the placement density of the buckling restrained braces 1 is relatively high, and a second placement region R2 where the placement density of the buckling restrained braces 1 is lower than that of the first placement region R1. The first placement region R1 and the second placement region R2 are virtual regions of the same size, and are regions partitioned based on the placement density of the buckling restrained braces 1 in the X direction. The first buckling restrained brace 1A is placed in the first placement region R1, and the second buckling restrained brace 1B is placed in the second placement region R2.

[0026] In the illustrated example, due to the offset in the placement of the buckling-restrained brace 1 in a plan view, a misalignment occurs between the center of rigidity and the center of gravity of the building 100A in a plan view, with the center of rigidity located closer to the first placement region R1 than the center of gravity in a plan view. In this case, when vibrations due to an earthquake or the like are input to the building 100A, the building 100A experiences torsional deformation centered on the center of rigidity of the building 100A. The amount of deformation is greater in the second placement region R2, which is farther from the center of rigidity, than in the first placement region R1, and a large force acts on the buckling-restrained brace 1 placed in the second placement region R2. By placing a second buckling-restrained brace 1B, which includes a second core member 10B made of a second steel material with a high yield strength, in the second placement region R2 as the buckling-restrained brace 1, the axial strength of the second buckling-restrained brace 1B can be improved and premature yielding of the second buckling-restrained brace 1B can be prevented. In this case, the axial strength of the second buckling restrained brace 1B can be improved without increasing its cross-sectional area, thereby suppressing an increase in the stiffness of the second buckling restrained brace 1B. In other words, by placing the second buckling restrained brace 1B in the second placement region R2, an increase in the stiffness of the second buckling restrained brace 1B can be suppressed while preventing the second buckling restrained brace 1B from prematurely yielding. Furthermore, because the axial strength of the second buckling restrained brace 1B can be improved without changing its stiffness, it becomes easier to adjust the stiffness balance of the building 100A, ensuring design freedom. Furthermore, because an increase in the stiffness of the second buckling restrained brace 1B can be suppressed, an increase in the force acting on the second buckling restrained brace 1B can be suppressed, preventing large pull-out forces from acting on the foundation located directly below the second buckling restrained brace 1B.

[0027] FIG. 4 is a schematic plan view showing another example of the placement of buckling restrained braces 1 on mixed floor F11. This example is applicable when the planar rigidity at the floor level is low, such as when the floor is missing. For example, a core section C where elevators, stairs, etc. are located may be provided on mixed floor F11. In the example shown, core section C is provided in the center of mixed floor F11. Because a relatively large number of columns and beams are provided in core section C to improve frame rigidity, there are many locations where buckling restrained braces 1 can be placed, and therefore the placement density of buckling restrained braces 1 can be increased. On the other hand, there are fewer locations where buckling restrained braces 1 can be placed in areas other than core section C compared to core section C, and therefore the placement density of buckling restrained braces 1 is lower. As a result, a first arrangement region R1, where the arrangement density of the buckling restrained braces 1 is relatively high, is formed in the center of the mixed floor F11 in the X direction, and a second arrangement region R2, where the arrangement density of the buckling restrained braces 1 is lower than that of the first arrangement region R1, is provided at both ends of the mixed floor F11 in the X direction. The second arrangement region R2 is also a low-rigidity region where the frame rigidity is lower than that of the first arrangement region R1. Therefore, when vibrations due to an earthquake or the like are input to the building 100A, the amount of deformation is greater in the second arrangement region R2 than in the first arrangement region R1. By placing the second buckling restrained braces 1B in the second arrangement region R2, it is possible to prevent the second buckling restrained braces 1B from yielding prematurely while suppressing an increase in their rigidity. In addition, since the axial strength of the second buckling restraint brace 1B is improved without changing the rigidity of the second buckling restraint brace 1B, it becomes easier to adjust the rigidity balance of the building 100A, ensuring design freedom.

[0028] FIG. 5 is a schematic plan view showing another example of the arrangement of buckling restrained braces 1 on the mixed floor F11. In the illustrated example, the core C is located on one side of the mixed floor F11 in the X direction. A first arrangement region R1, where the arrangement density of the buckling restrained braces 1 is relatively high, is formed on one side of the mixed floor F11 in the X direction. A second arrangement region R2, where the arrangement density of the buckling restrained braces 1 is lower than that of the first arrangement region R1, is formed on the other side of the mixed floor F11 in the X direction. In this case, too, by arranging the second buckling restrained braces 1B in the second arrangement region R2, it is possible to suppress an increase in the stiffness of the second buckling restrained braces 1B while preventing the second buckling restrained braces 1B from yielding prematurely. Furthermore, because the axial strength of the second buckling restrained braces 1B is improved without changing their stiffness, it becomes easier to adjust the stiffness balance of the building 100A, ensuring design flexibility.

[0029] As described above, the building 100A of this embodiment is a building 100A provided with a plurality of buckling restraint braces 1, each of which comprises a core material 10 and a restraint material 30 that restrains the buckling of the core material 10, and the plurality of buckling restraint braces 1 include a first buckling restraint brace 1A having, as the core material 10, a first core material 10A made of a first steel type, and a second buckling restraint brace 1B having, as the core material 10, a second core material 10B made of a second steel type that has a higher yield strength than the first steel type. According to the above configuration, the building 100A is provided with a first buckling restrained brace 1A and a second buckling restrained brace 1B as buckling restrained braces 1. This makes it possible to improve the axial strength of the buckling restrained brace 1 (second buckling restrained brace 1B) in the area where the second buckling restrained brace 1B is provided, without changing the cross-sectional area of ​​the buckling restrained brace 1 (second buckling restrained brace 1B), i.e., without changing the rigidity of the buckling restrained brace 1. This makes it easy to adjust the rigidity balance of the building 100A when placing the buckling restrained braces 1, improving design freedom.

[0030] Furthermore, the first buckling restraint brace 1A and the second buckling restraint brace 1B are provided at the same height. For example, if the frame stiffness is uneven across a particular floor of building 100A, the amount of deformation in the low-stiffness area, where the frame stiffness is lower, will be greater than in other areas. If all the buckling restrained braces installed in a building are the same, the buckling restrained braces installed in the low-stiffness area will yield prematurely. In response to this, by installing a second buckling restrained brace 1B with a second core material 10B made of a second steel material with a high yield strength as the buckling restrained brace 1 in the low-stiffness area, it is possible to prevent the second buckling restrained brace 1B from yielding prematurely while suppressing an increase in the stiffness of the second buckling restrained brace 1B.

[0031] The building 100A also has a mixed floor F11 where multiple buckling restraint braces 1 including both the first buckling restraint brace 1A and the second buckling restraint brace 1B are arranged, and a non-mixed floor F12 where multiple buckling restraint braces 1 consisting of only the first buckling restraint brace 1A or the second buckling restraint brace 1B are arranged. Even if the configuration differs from floor to floor in building 100A, design freedom can be improved by providing mixed floors F11 and non-mixed floors F12 according to the configuration of each floor. For example, on floors where the frame stiffness is uneven in plan view, multiple buckling restrained braces 1 including both first buckling restrained braces 1A and second buckling restrained braces 1B can be placed, and on floors where the frame stiffness is not uneven in plan view, multiple buckling restrained braces 1 consisting of only either the first buckling restrained braces 1A or the second buckling restrained braces 1B can be placed.

[0032] In addition, the building 100A has a mixed floor F11 on which multiple buckling restraint braces 1, including both the first buckling restraint brace 1A and the second buckling restraint brace 1B, are arranged, and on the mixed floor F11, multiple buckling restraint braces 1 are distributed at different positions in a plan view, and on the mixed floor F11, there are a first placement area R1 and a second placement area R2 in which the placement density of the buckling restraint braces 1 is lower than that of the first placement area R1, and the first buckling restraint brace 1A is arranged in the first placement area R1, and the second buckling restraint brace 1B is arranged in the second placement area R2. Second buckling restrained braces 1B equipped with second core materials 10B made of a second steel material with high yield strength are arranged in the second arrangement region R2, where the arrangement density of the buckling restrained braces 1 is low. This prevents the buckling restrained braces 1 arranged in the second arrangement region R2 from prematurely yielding, even if the arrangement of the buckling restrained braces 1 is uneven in plan, causing a misalignment between the center of rigidity and the center of gravity of the building 100A in plan view. Furthermore, because the axial strength of the second buckling restrained braces 1B is improved without changing their rigidity, it becomes easier to adjust the rigidity balance of the building 100A, ensuring design freedom.

[0033] Furthermore, the first buckling restrained brace 1A and the second buckling restrained brace 1B have the same axial rigidity. This configuration makes it easier to adjust the rigidity balance of the building 100A, and allows for greater freedom in design.

[0034] Second Embodiment Next, a building 100B according to a second embodiment of the present disclosure will be described with reference to Fig. 6. In this embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and their description will be omitted, with only the differences being described.

[0035] In this embodiment, the building 100B has a first floor F22 whose floor height is a first height and a second floor F21 whose floor height is higher than the first height. The first floor F22 and the second floor F21 are arranged adjacent to each other in the vertical direction. In the illustrated example, the first floor F22 is arranged above the second floor F21. An open area such as an entrance is formed on the second floor F21. The first buckling restraint brace 1A is arranged on each of the multiple floors of the building 100A except for the second floor F21, and the second buckling restraint brace 1B is arranged on the second floor F21.

[0036] Because the columns located in the open area of ​​the second floor F21 run between the second floor F21 and the first floor F22 located adjacent to the second floor F21, it is difficult to ensure sufficient rigidity for the second floor F21 solely through frame design, such as adjusting the thickness of the columns. As a result, a difference in rigidity occurs between the second floor F21 and the first floor F22, and buckling restraint braces 1 are installed on the second floor F21 to reinforce the second floor F21. If the buckling-restrained braces on the second floor (F21) were made with the same core steel type as those used on other floors, the cross-sectional area of ​​the core would need to be increased to ensure the required axial strength, resulting in higher stiffness of the buckling-restrained braces. As a result, the load would be concentrated on the buckling-restrained braces on the second floor (F21), causing them to yield earlier than the buckling-restrained braces on other floors. On the other hand, to prevent the load from concentrating on the buckling-restrained braces on the second floor (F21), it would be possible to reduce the cross-sectional area of ​​the core material, reducing the stiffness of the buckling-restrained braces and shifting the load to the frame. However, this would also reduce the axial strength of the buckling-restrained braces. Thus, using only buckling-restrained braces with the same core steel type would make building design difficult. In this embodiment, by placing second buckling restrained braces 1B with second core members 10B made of a second steel material with high yield strength on the second floor F21, it is possible to improve the axial strength of the second buckling restrained braces 1B while suppressing an increase in the stiffness of the second buckling restrained braces 1B. In other words, it is possible to ensure the axial strength required of the second buckling restrained braces 1B while suppressing an increase in the stiffness of the second buckling restrained braces 1B, thereby preventing the second buckling restrained braces 1B from yielding prematurely. Furthermore, because the axial strength of the second buckling restrained braces 1B is improved without changing their stiffness, it becomes easier to adjust the stiffness balance of the building 100B, ensuring design flexibility.

[0037] As described above, the building 100B of this embodiment includes a first floor F22 having a floor height of a first height, and a second floor F21 arranged vertically adjacent to the first floor F22 and having a floor height higher than the first height, and the first buckling restraint brace 1A is arranged on a floor other than the second floor F21, and the second buckling restraint brace 1B is arranged on the second floor F21. This improves the axial strength of the second buckling restrained brace 1B while suppressing an increase in the stiffness of the second buckling restrained brace 1B, thereby preventing the second buckling restrained brace 1B from yielding prematurely. It also makes it easier to adjust the stiffness balance of the building 100B, ensuring design freedom.

[0038] <Third embodiment> Next, a building 100C according to a third embodiment of the present disclosure will be described with reference to Fig. 7. In this embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and their description will be omitted, with only the differences being described.

[0039] The building 100C is, for example, a high-rise building. An intermediate-story seismic isolation M is provided in the middle of the building 100C. The building 100C comprises a low-rise section L arranged between the ground G and the intermediate-story seismic isolation M, and an upper section H arranged above the low-rise section L with the intermediate-story seismic isolation M in between. The intermediate-story seismic isolation M has multiple seismic isolation devices 104. When seismic motion occurs, the seismic isolation devices 104 cause relative displacement between the high-rise section H and the low-rise section L in the horizontal direction. This prevents vibrations from the low-rise section L from being transmitted to the high-rise section H. A first buckling restraint brace 1A is arranged in the high-rise section H, and a second buckling restraint brace 1B is arranged in the low-rise section L.

[0040] When vibrations caused by an earthquake or other events are input to building 100C, if the core material of the buckling-restrained braces installed in the lower floors L undergoes plastic deformation, the vibration mode of the lower floors L will change, preventing effective seismic isolation by mid-story isolation M, and there is a possibility that the seismic vibrations will be transmitted to the upper floors H. Therefore, it is desirable for the core material of the buckling-restrained braces installed in the lower floors L to remain elastically deformed rather than undergo plastic deformation, even during a major earthquake. Furthermore, in high-rise buildings, column-free spaces or rigid-frame structures are often provided on the lower floors of the lower floors L to ensure common spaces such as entrances, and the lower floors of the lower floors L are often high in height. In such cases, it is necessary to effectively install buckling-restrained braces 1 in the lower floors L of building 100C. In this embodiment, by placing a second buckling restrained brace 1B with a second core material 10B made of a second steel material with high yield strength in the low-rise section L, the axial strength of the second buckling restrained brace 1B can be improved while suppressing an increase in the rigidity of the second buckling restrained brace 1B. As a result, even during a large earthquake, the second core material 10B does not undergo plastic deformation, and deformation of the second core material 10B can be kept within the elastic range. Therefore, even if vibrations caused by an earthquake or other events are input to the building 100C, the mid-story seismic isolation M can effectively isolate the building 100C, preventing the seismic vibrations from being transmitted to the high-rise section H. In other words, the elastic range of the entire low-rise section L, including the buckling restrained brace 1 and the frame, can be expanded while maintaining the rigidity balance of the building 100C. Furthermore, because the axial strength of the second buckling restrained brace 1B is improved without changing its rigidity, it is easy to adjust the rigidity balance of the building 100C, ensuring design flexibility.

[0041] As described above, the building 100C of this embodiment comprises a low-rise section L arranged between the ground G and the mid-story seismic isolation M, and a high-rise section H arranged above the low-rise section L, sandwiching the mid-story seismic isolation M between them, and the first buckling restraint brace 1A is arranged in the high-rise section H, and the second buckling restraint brace 1B is arranged in the low-rise section L. This makes it possible to expand the elastic range of the entire lower section L, including the buckling restraint braces 1 and the frame, while maintaining the rigidity balance of the building 100C. In addition, it becomes easier to adjust the rigidity balance of the building 100C, ensuring design freedom.

[0042] The present disclosure is not limited to the above-described embodiment described with reference to the drawings, and various modifications are possible within the technical scope thereof.

[0043] For example, buildings 100A, 100B, and 100C according to the first to third embodiments may be provided with a third buckling restrained brace having a third core material made of a third steel type that is different from both the first steel type and the second steel type. For example, the third steel type has a different yield strength from the first steel type and the second steel type.

[0044] In addition, in building 100A, a second non-mixed floor on which multiple buckling restraint braces 1 are arranged may be provided, and all of the multiple buckling restraint braces 1 arranged on the second non-mixed floor may be third buckling restraint braces. This configuration allows for greater freedom in design.

[0045] In addition, building 100A may have a second mixed floor where both the first buckling restraint brace 1A and the third buckling restraint brace are arranged, or a third mixed floor where the first buckling restraint brace 1A, the second buckling restraint brace 1B, and the third buckling restraint brace are arranged.

[0046] Furthermore, in the building 100B according to the second embodiment, the second buckling restraint brace 1B may be arranged on a floor other than the second floor F21.

[0047] Furthermore, in the buildings 100A and 100B, mid-story seismic isolation may be provided in the middle of the buildings 100A and 100B.

[0048] In addition, within the scope of the present disclosure, the components in the above-described embodiments may be replaced with well-known components as appropriate, and the above-described modified examples may be combined as appropriate.

[0049] Various aspects of the present disclosure are summarized below as appendices.

[0050] (Appendix 1) A building provided with a plurality of buckling restraint braces, The buckling restrained brace includes a core material and a restraint material that restrains buckling of the core material, The plurality of buckling restrained braces include a first buckling restrained brace having a first core material made of a first steel type as the core material, and a second buckling restrained brace having a second core material made of a second steel type as the core material, the second steel type having a higher yield strength than the first steel type.

[0051] (Appendix 2) 2. The building of claim 1, wherein the first buckling restraint brace and the second buckling restraint brace are located at the same height.

[0052] (Appendix 3) There are several floors, The floors are: a mixed floor on which a plurality of the buckling restrained braces, including both the first buckling restrained brace and the second buckling restrained brace, are arranged; a non-mixed floor on which a plurality of buckling restrained braces consisting of only one of the first buckling restrained braces or the second buckling restrained braces are arranged; A building as described in Appendix 1 or 2, which is provided with:

[0053] (Appendix 4) There are several floors, A second non-mixed floor on which a plurality of the buckling restraint braces are arranged is provided as the floor, A building described in any one of Appendices 1 to 3, wherein all of the multiple buckling restraint braces arranged on the second non-mixed floor are third buckling restraint braces having a third core material made of a third steel type that is different from both the first steel type and the second steel type.

[0054] (Appendix 5) a mixed floor on which a plurality of the buckling restrained braces including both the first buckling restrained brace and the second buckling restrained brace are arranged; On the mixed floor, a plurality of the buckling restraint braces are provided at different positions in a plan view, In the mixed floor, there are a first arrangement area and a second arrangement area in plan view in which the arrangement density of the buckling restraint braces is lower than that of the first arrangement area, the first buckling restraint brace is disposed in the first disposition region; The building described in any one of appendixes 1 to 4, wherein the second buckling restraint brace is arranged in the second arrangement area.

[0055] (Appendix 6) 6. The building described in Appendix 5, wherein the first buckling restraint brace and the second buckling restraint brace have the same axial stiffness.

[0056] (Appendix 7) There are several floors, The floors are: The first floor has a first height, a second floor arranged vertically adjacent to the first floor and having a floor height higher than the first height; is established, the first buckling restraint brace is disposed on a floor other than the second floor, 2. The building of claim 1, wherein the second buckling restrained brace is located on the second floor.

[0057] (Appendix 8) The building comprises a low-rise section disposed between the ground and the mid-story seismic isolation, and a high-rise section disposed above the low-rise section with the mid-story seismic isolation in between, the first buckling restraint brace is disposed in the upper section; 2. The building of claim 1, wherein the second buckling restraint brace is located in the lower section. [Explanation of symbols]

[0058] 100A, 100B, 100C Buildings 1. Buckling-restrained brace 1A First buckling restrained brace (buckling restrained brace) 1B Second buckling restrained brace (buckling restrained brace) 10 Core material 10A First core material (core material) 10B Second core material (core material) 30 Restraint material F11 Mixed Floor F12 Non-mixed floor F22 1st floor F21 2nd floor H High-rise section L Lower part M Mid-story seismic isolation G Ground R1 1st placement area R2 2nd placement area

Claims

1. A building provided with a plurality of buckling restraint braces, The buckling restrained brace includes a core material and a restraint material that restrains buckling of the core material, The plurality of buckling restrained braces include a first buckling restrained brace having, as the core material, a first core material made of a first steel type, and a second buckling restrained brace having, as the core material, a second core material made of a second steel type that has a higher yield strength than the first steel type.

2. The building according to claim 1 , wherein the first buckling restrained brace and the second buckling restrained brace are provided at the same height.

3. There are several floors, The floors are: a mixed floor on which a plurality of the buckling restrained braces, including both the first buckling restrained brace and the second buckling restrained brace, are arranged; a non-mixed floor on which a plurality of buckling restrained braces consisting of only one of the first buckling restrained braces or the second buckling restrained braces are arranged; The building according to claim 1 , wherein:

4. There are several floors, A second non-mixed floor on which a plurality of the buckling restraint braces are arranged is provided as the floor, 2. The building described in claim 1, wherein all of the plurality of buckling restrained braces arranged on the second non-mixed floor are third buckling restrained braces having a third core material made of a third steel type different from both the first steel type and the second steel type as the core material.

5. a mixed floor on which a plurality of the buckling restrained braces including both the first buckling restrained brace and the second buckling restrained brace are arranged; On the mixed floor, a plurality of the buckling restraint braces are provided at different positions in a plan view, In the mixed floor, as areas in a plan view, there are a first arrangement area and a second arrangement area in which the arrangement density of the buckling restraint braces is lower than that of the first arrangement area, the first buckling restraint brace is disposed in the first arrangement region; The building of claim 1 , wherein the second buckling restraint brace is disposed in the second placement area.

6. The building according to claim 5 , wherein the first buckling restrained brace and the second buckling restrained brace have the same axial stiffness.

7. There are several floors, The floors are: a first floor having a first floor height; a second floor arranged adjacent to the first floor in the vertical direction and having a floor height higher than the first height; is established, the first buckling restraint brace is disposed on a floor other than the second floor, The building of claim 1 , wherein the second buckling restrained brace is located on the second floor.

8. The building comprises a low-rise section disposed between the ground and the mid-story seismic isolation, and a high-rise section disposed above the low-rise section with the mid-story seismic isolation in between, the first buckling restraint brace is disposed in the upper section, The building according to claim 1 , wherein the second buckling restraint brace is disposed in the lower floor section.

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