Building structure

Abstract

To provide a building structure including a plurality types of load support members having different rigidities, the building structure being capable of improving earthquake resistance.SOLUTION: A building structure 1 includes a reference support member 3 and a specific support member 4 having higher rigidity than that of the reference support member 3. The specific support member 4 includes a first H-shaped steel 41 and a second H-shaped steel 42. In the specific support member 4, the first H-shaped steel 41 and the second H-shaped steel 42 have axial one end 4A rigidly bonded to a first bonded member 2A and axial another end 4B rigidly bonded to a second bonded member 2B. In a first inner flange 411A in the first H-shaped steel 41 and a second inner flange 421A in the second H-shaped steel 42, welding portions 5A, 5B are formed only on both sides in a predetermined non-welding region 4C1 including an axial center point 4C so that the first inner flange 411A and the second inner flange 421A are not bonded in the non-welding region 4C1.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to building structures. [Background technology]

[0002] Rigid frame building structures applied to buildings are designed to resist loads such as earthquake forces by rigidly connecting one and the other axial ends of load-bearing members such as columns to connected members. A load-bearing member applicable to this type of building structure is disclosed in Patent Document 1.

[0003] The load support member disclosed in Patent Document 1 has a structure in which two H-shaped steel members are welded together with their inner flanges in contact with each other. A load support member having such a structure can ensure high rigidity and strength against loads such as earthquake forces, compared to a support member made of a single H-shaped steel member. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6382363 Summary of the Invention [Problem to be solved by the invention]

[0005] In a building structure, a plurality of load-bearing members having different rigidities may be used. For example, as disclosed in Patent Document 1, a specific support member made of two H-shaped steels welded together and a standard support member having a predetermined rigidity lower than that of the specific support member may be used to constitute the load-bearing members of the building structure. In a building structure having such a configuration, the standard support member and the specific support member having different rigidities cooperate to resist loads such as earthquake forces. In this case, the load distributed to each support member differs depending on the rigidity of each support member, and the load distributed to the specific support member having a high rigidity and borne by the specific support member is larger than that of the standard support member.

[0006] When the load is distributed to each support member, the load borne by the specific support member may become excessively large compared to the standard support member. If the load borne by the specific support member exceeds the yield strength, the specific support member will reach plastic deformation earlier than the standard support member. As a result, it will be impossible to effectively utilize the strengths of the specific support member and the standard support member to resist the load applied to the building structure, and there is a risk that it will not be possible to efficiently improve the earthquake resistance of the building structure.

[0007] The present invention has been made in consideration of the above circumstances, and its object is to provide a building structure that is equipped with multiple types of load-supporting members with different rigidity and that can improve earthquake resistance. [Means for solving the problem]

[0008] As a result of intensive research to solve the above problems, the inventors focused on the fact that a large bending moment acts on both axial ends of a load support member when a load is applied to a building structure, and discovered that by adjusting the welding positions of the two H-shaped steels that make up the specific support member, it is possible to reduce the rigidity of the specific support member while ensuring the strength of the necessary parts of the specific support member, leading to the completion of the present invention. That is, the present invention relates to the following inventions.

[0009] A building structure according to one aspect of the present invention includes a reference support member having a predetermined rigidity and supporting a load, a specific support member having a rigidity higher than that of the reference support member and supporting a load, a first joined member to which one axial end of the reference support member is rigidly joined to one axial end of the specific support member, and a second joined member to which the other axial end of the reference support member is rigidly joined to the other axial end of the specific support member. The specific support member includes a first H-shaped steel having a pair of first flanges and a first web connecting the first flanges to each other, and a second H-shaped steel having a pair of second flanges and a second web connecting the second flanges to each other. In this case, one of the pair of first flanges and one of the pair of second flanges are welded to each other by a weld with their outer surfaces in contact with each other, and the weld is formed only on both sides of the specified region including the axial center points of the first H-shaped steel and the second H-shaped steel so that one of the pair of first flanges and one of the pair of second flanges are not joined in the specified region.

[0010] According to this building structure, when a load such as an earthquake force is applied to the building structure, the reference support member and the specific support member, which have different rigidity, cooperate to resist the load. At this time, when the load applied to the building structure is distributed to each of the reference support member and the specific support member, the load is distributed to the specific support member with higher rigidity, and the load borne by the specific support member becomes larger than that of the reference support member.

[0011] Here, when a load is applied to the building structure, the first and second H-shaped steels constituting the specific support member are subjected to the largest bending moment at one end and the other end in the axial direction that are rigidly joined to the first joined member and the second joined member, respectively, and the bending moment becomes smaller as the end approaches the axial center point. In consideration of this point, in the specific support member, the first flange of the first H-shaped steel and the second flange of the second H-shaped steel are welded to each other by forming welds only on both sides of a specific region including the axial center point so that they are not joined in the specific region. By forming welds in both axial end and other end regions on both sides of the specific region including the axial center point where a large bending moment acts, the specific support member can ensure the strength required to resist the load.

[0012] Moreover, in the specific support member, the predetermined region including the center point in the axial direction where the bending moment is small becomes a non-welded region where no weld is formed. As a result, it is possible to suppress the increase rate of the rigidity becoming excessively larger than the yield strength with respect to the increase rate of the rigidity and the yield strength in response to the formation of the weld on both sides of the predetermined region in the specific support member. That is, in the specific support member, the decrease rate of the rigidity becomes larger than the yield strength in response to the non-welded region. Therefore, it is possible to reduce the rigidity of the specific support member while ensuring the yield strength on both sides of the non-welded region in the specific support member. As a result, when the load applied to the building structure is distributed to each support member according to the magnitude of each of the standard support member and the specific support member, it is possible to suppress the load borne by the specific support member becoming excessively large relative to the standard support member. Therefore, the load is distributed according to the magnitude of the yield strength of each support member, and it is possible to suppress the specific support member from becoming plastically deformed earlier than the standard support member, and it is possible to effectively utilize the respective yield strengths of the specific support member and the standard support member to resist the load, thereby improving the earthquake resistance of the building structure.

[0013] In the above building structure, the welded portion has a first welded portion formed including one axial end portion of the first H-shaped steel and the second H-shaped steel, and a second welded portion formed including the other axial end portion of the first H-shaped steel and the second H-shaped steel.

[0014] In this aspect, in the first and second H-shaped steel that constitute the specific support member, a first welded portion is formed including one axial end portion where the largest bending moment acts, and a second welded portion is formed including the other axial end portion, so that the strength required for the specific support member to resist loads can be more reliably secured.

[0015] In the above building structure, the welded portion is formed continuously over the entire areas on both sides of the specified area.

[0016] In this aspect, in the first and second H-shaped steel that constitute the specific support member, welds are formed continuously over the entire area on one and the other axial ends, which are on both sides of a specific area including the axial center point where a large bending moment acts, so that the strength required for the specific support member to resist loads can be more reliably secured.

[0017] In the above building structure, the welds are formed symmetrically in the axial direction on both sides of the specified area.

[0018] In this embodiment, the specific support member can support the load evenly at each of one and the other axial ends.

[0019] In the above building structure, the axial length of the weld is set so that the rigidity ratio indicating the ratio of the rigidity of the specific support member to the rigidity of the reference support member and the strength ratio indicating the ratio of the strength of the specific support member to the strength of the reference support member are approximately equal.

[0020] In this embodiment, the length of the weld is set so that the stiffness ratio and the strength ratio of the reference support member and the specific support member are approximately equal. This makes it possible to more reliably prevent the stiffness increase rate of the specific support member from becoming excessively larger than the strength, with respect to the stiffness and strength increase rate of the reference support member. Therefore, when the load applied to the building structure is distributed to each support member according to the stiffness of the reference support member and the specific support member, it is possible to more reliably prevent the load borne by the specific support member from becoming excessively larger than that of the reference support member.

[0021] In the above building structure, the first web has a through hole penetrating the first web in its thickness direction formed at least on both sides of the specified area, and the welded portion is formed in an area covering at least half of the through hole when viewed from a direction perpendicular to the axial direction.

[0022] In this embodiment, a through hole is formed in the first web of the first H-shaped steel constituting the specific support member. A worker can use the through hole when performing work such as placing a wall panel on the specific support member. In addition, when a load is applied to the building structure, there is a risk that plastic deformation may easily occur around the through hole. Therefore, the weld is formed in an area that covers at least half of the through hole when viewed from a direction perpendicular to the axial direction. This makes it possible to suppress the occurrence of plastic deformation around the through hole. Effect of the Invention

[0023] As described above, according to the present invention, it is possible to provide a building structure that is equipped with a plurality of types of load supporting members having different rigidities, and that is capable of improving earthquake resistance. [Brief description of the drawings]

[0024] [Figure 1] 1 is a perspective view showing a building structure according to an embodiment of the present invention; [Diagram 2] This is a horizontal plan view of the building structure. [Diagram 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Diagram 5] 1 is a graph showing a load-displacement curve of a support member when a horizontal load is applied to a building structure. [Figure 6] 1 is a plan view showing the configuration of a specific support member provided in a building structure. FIG. [Figure 7] FIG. 11 is a plan view showing a first modified example of a welded portion in a specific support member. [Figure 8] FIG. 11 is a plan view showing a second modified example of a welded portion in a specific support member. [Figure 9] FIG. 13 is a plan view showing a third modified example of a welded portion in a specific support member. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Hereinafter, a building structure according to an embodiment of the present invention will be described with reference to the drawings.

[0026] 1 and 2, a building structure 1 includes a first joined member 2A, a second joined member 2B, a reference support member 3, and a specific support member 4. In the building structure 1, the reference support member 3 and the specific support member 4 are applied to columns, beams, and the like for supporting a load. Below, a case will be described in which the reference support member 3 and the specific support member 4 are applied to columns of the building structure 1. In this case, the first joined member 2A and the second joined member 2B are applied to beams of the building structure 1.

[0027] The first member 2A to be joined is a beam extending horizontally. The second member 2B to be joined is a beam extending horizontally vertically below the first member 2A. The second member 2B may be a building foundation. The first member 2A to be joined and the second member 2B to be joined support the reference support member 3 and the specific support member 4. The first member 2A to be joined and the second member 2B to be joined are, for example, H-shaped steel. In this case, the first member 2A to be joined and the second member 2B to be joined each have a pair of joining flanges 211 and a joining web 212 connecting the two joining flanges 211 to each other. The first member 2A to be joined and the second member 2B to be joined are arranged so that the pair of joining flanges 211 extend horizontally while being aligned vertically.

[0028] The reference support member 3 and the specific support member 4 are applied to columns rigidly joined to the first and second joined members 2A and 2B so that their axial directions are parallel to the vertical direction, and are column materials that support loads. The reference support member 3 and the specific support member 4 are supported by the first and second joined members 2A and 2B at a predetermined interval in the horizontal direction. In the building structure 1, wall panels and the like are placed relative to the reference support member 3 and the specific support member 4. The area of ​​a cross section perpendicular to the axial direction in the reference support member 3 is set to a predetermined reference cross-sectional area. On the other hand, the area of ​​a cross section perpendicular to the axial direction in the specific support member 4 is set to a specific cross-sectional area larger than the reference cross-sectional area.

[0029] The reference support member 3 is composed of a reference H-shaped steel 31, which is a single H-shaped steel. The reference H-shaped steel 31 is a steel material extending along the axial direction, and has a pair of flanges 311 and a web 312 connecting the flanges 311 to each other. The web 312 of the reference H-shaped steel 31 has a plurality of through holes 312A that penetrate the web 312 in its thickness direction. The plurality of through holes 312A have a shape that allows a person (worker) to insert their hand therethrough, and are formed at predetermined intervals in the axial direction in the web 312. The worker can use the through holes 312A when performing work such as arranging a wall panel on the reference support member 3.

[0030] The reference H-shaped steel 31 constituting the reference support member 3 has one axial end 3A (upper end) rigidly joined to the first joined member 2A and the other axial end 3B (lower end) rigidly joined to the second joined member 2B. In this embodiment, the reference H-shaped steel 31 has one end 3A rigidly joined to the joining flange 211 of the first joined member 2A via a one-end base plate 32, and the other end 3B rigidly joined to the joining flange 211 of the second joined member 2B via a other-end base plate 33.

[0031] Specifically, one end 3A of the standard H-shaped steel 31 is welded (fillet welded) in a state of contact with the one-end base plate 32. As a result, a welded portion 32A is formed at the boundary between the one end 3A of the standard H-shaped steel 31 and the one-end base plate 32. The one-end base plate 32 is then fixed to the joining flange 211 of the first joined member 2A by the bolts 34. As a result, the one end 3A of the standard H-shaped steel 31 is rigidly joined to the first joined member 2A. Meanwhile, the other end 3B of the standard H-shaped steel 31 is welded (fillet welded) in a state of contact with the other-end base plate 33. As a result, a welded portion 33A is formed at the boundary between the other end 3B of the standard H-shaped steel 31 and the other-end base plate 33. The other-end base plate 33 is then fixed to the joining flange 211 of the second joined member 2B by the bolts 34. As a result, the other end 3B of the standard H-shaped steel 31 is rigidly joined to the second joined member 2B.

[0032] The specific support member 4 includes a first H-shaped steel 41 and a second H-shaped steel 42 having the same shape as the standard H-shaped steel 31. The first H-shaped steel 41 is a steel material extending along the axial direction, and has a pair of first flanges 411A, 411B and a first web 412 connecting the first flanges 411A, 411B to each other. The second H-shaped steel 42 is a steel material extending along the axial direction, and has a pair of second flanges 421A, 421B and a second web 422 connecting the second flanges 421A, 421B to each other.

[0033] The first H-shaped steel 41 and the second H-shaped steel 42 are arranged in such a manner that the first web 412 and the second web 422 are aligned on the same vertical plane, and the first inner flange 411A of the pair of first flanges 411A, 411B and the second inner flange 421A of the pair of second flanges 421A, 421B are adjacent to each other. In this state, the other first outer flange 411B of the pair of first flanges 411A, 411B and the other second outer flange 421B of the pair of second flanges 421A, 421B form the outer surface of the specific support member 4. In the first H-shaped steel 41 and the second H-shaped steel 42, the first inner flange 411A and the second inner flange 421A adjacent to each other are welded to each other (fillet welded) by the first welded portion 5A and the second welded portion 5B with their outer surfaces in contact with each other. The welded points between first inner flange 411A and second inner flange 421A will be described in detail later.

[0034] A first web 412 of the first H-shaped steel 41 has a plurality of first through holes 412A penetrating the first web 412 in its thickness direction. The plurality of first through holes 412A have a shape that allows a person (worker) to insert their hand therethrough, and are formed at a predetermined interval in the axial direction in the first web 412. Similarly, a second web 422 of the second H-shaped steel 42 has a plurality of second through holes 422A penetrating the second web 422 in its thickness direction. The plurality of second through holes 422A have a shape that allows a person (worker) to insert their hand therethrough, and are formed at a predetermined interval in the axial direction in the second web 422. A worker can use the first through holes 412A and the second through holes 422A when performing work such as arranging a wall panel on the specific support member 4.

[0035] In addition, the first through hole 412A and the second through hole 422A also have the function of absorbing the vibration energy transmitted to the specific support member 4 when a horizontal load P such as an earthquake force is applied to the building structure 1, and attenuating the shaking of the building structure 1.

[0036] The first H-shaped steel 41 and the second H-shaped steel 42 constituting the specific support member 4 have one axial end 4A (upper end) rigidly joined to the first joined member 2A and the other axial end 4B (lower end) rigidly joined to the second joined member 2B. In this embodiment, the first H-shaped steel 41 and the second H-shaped steel 42 have one end 4A rigidly joined to the joining flange 211 of the first joined member 2A via a first base plate 61 and the other end 4B rigidly joined to the joining flange 211 of the second joined member 2B via a second base plate 62.

[0037] Specifically, one end 4A of the first H-shaped steel 41 and the second H-shaped steel 42 is welded (fillet welded) in a state of contact with the first base plate 61. As a result, a one-end welded portion 61E is formed at the boundary portion between the one end 4A of the first H-shaped steel 41 and the second H-shaped steel 42 and the first base plate 61. The first base plate 61 is then fixed to the joining flange 211 of the first joined member 2A by the bolt 63. As a result, the one end 4A of the first H-shaped steel 41 and the second H-shaped steel 42 is rigidly joined to the first joined member 2A. Meanwhile, the other end 4B of the first H-shaped steel 41 and the second H-shaped steel 42 is welded (fillet welded) in a state of contact with the second base plate 62. As a result, a other-end welded portion 62E is formed at the boundary portion between the other end 4B of the first H-shaped steel 41 and the second H-shaped steel 42 and the second base plate 62. The second base plate 62 is fixed to the joining flange 211 of the second joined member 2B by the bolts 63. As a result, the other ends 4B of the first H-shaped steel 41 and the second H-shaped steel 42 are rigidly joined to the second joined member 2B.

[0038] As shown in FIG. 3, the first base plate 61 has a first central receiving portion 61A, a pair of first outer receiving portions 61B, and a first connecting portion 61C that connects the first central receiving portion 61A and the pair of first outer receiving portions 61B. The first central receiving portion 61A receives one end of the first inner flange 411A and one end of the second inner flange 421A of the one end 4A of the first H-shaped steel 41 and the second H-shaped steel 42. The pair of first outer receiving portions 61B receive one end of the first outer flange 411B and one end of the second outer flange 421B of the one end 4A of the first H-shaped steel 41 and the second H-shaped steel 42. The first connecting portion 61C receives one end of the first web 412 and one end of the second web 422 of the one end 4A of the first H-shaped steel 41 and the second H-shaped steel 42. The first central receiving portion 61A and the pair of first outer receiving portions 61B are formed with bolt holes 61D for passing bolts 63 for fixing the first base plate 61 to the joining flange 211 of the first joined member 2A.

[0039] As shown in FIG. 4, the second base plate 62 has a second central receiving portion 62A, a pair of second outer receiving portions 62B, and a second connecting portion 62C that connects the second central receiving portion 62A and the pair of second outer receiving portions 62B. The second central receiving portion 62A receives the other ends of the first inner flange 411A and the second inner flange 421A of the other ends 4B of the first H-shaped steel 41 and the second H-shaped steel 42. The pair of second outer receiving portions 62B receive the other ends of the first outer flange 411B and the second outer flange 421B of the other ends 4B of the first H-shaped steel 41 and the second H-shaped steel 42. The second connecting portion 62C receives the other ends of the first web 412 and the second web 422 of the other ends 4B of the first H-shaped steel 41 and the second H-shaped steel 42. The second central receiving portion 62A and the pair of second outer receiving portions 62B are formed with bolt holes 62D for passing bolts 63 for fixing the second base plate 62 to the joining flange 211 of the second joined member 2B.

[0040] In the first H-shaped steel 41 and the second H-shaped steel 42 constituting the specific support member 4, the setting of the dimension (width dimension) in the width direction (direction perpendicular to the first web 412 and the second web 422) of each of the first inner flange 411A, the first outer flange 411B, the second inner flange 421A, and the second outer flange 421B is not particularly limited. In the first example, the width dimensions of each of the first inner flange 411A, the first outer flange 411B, the second inner flange 421A, and the second outer flange 421B are all set to be the same. In the second example, the width dimensions of each of the first inner flange 411A, the first outer flange 411B, and the second outer flange 421B are set to the same first width dimension, and the width dimension of the second inner flange 421A is set to a second width dimension smaller than the first width dimension. In a third example, the width dimensions of the first outer flange 411B and the second outer flange 421B are set to the same third width dimension, and the width dimensions of the first inner flange 411A and the second inner flange 421A are set to the same fourth width dimension that is smaller than the third width dimension.

[0041] As described above, in the first H-shaped steel 41 and the second H-shaped steel 42 constituting the specific support member 4, the adjacent first inner flange 411A and the second inner flange 421A are welded to each other by the welds 5A, 5B with their outer surfaces in contact with each other. Specifically, as shown in Fig. 2, the first inner flange 411A and the second inner flange 421A are not joined in the non-welded region 4C1, which is a predetermined region including the axial center point 4C of the first H-shaped steel 41 and the second H-shaped steel 42, so that the welds 5A, 5B are formed only on both sides of the non-welded region 4C1. In other words, a first welded portion 5A is formed in a first welded region 4A1 on one end 4A of a non-welded region 4C1 including the axial center point 4C of the first H-shaped steel 41 and the second H-shaped steel 42 in the first inner flange 411A and the second inner flange 421A, and a second welded portion 5B is formed in a second welded region 4B1 on the other end 4B of the non-welded region 4C1.

[0042] Next, the rigidity and strength of the standard support member 3 and the specific support member 4 will be described with reference to the load-displacement curve graph shown in FIG. 5. The graph in FIG. 5 shows the load-displacement curve E1 of the specific support member 4, the load-displacement curve E2 of the standard support member 3, and the load-displacement curve E3 of the conventional support member. The conventional support member is a conventional support member in which a pair of adjacent inner flanges of two H-shaped steels are welded together over the entire axial length. The conventional support member is configured in the same way as the specific support member 4 except that the welded points are different from those of the specific support member 4, and the cross-sectional area is larger than that of the standard support member 3.

[0043] In this embodiment, in a state where one axial end and the other axial end of the reference support member 3 and the specific support member 4 are fixed by rigid joining to the first joined member 2A and the second joined member 2B, the initial rigidity is used as the rigidity of each support member, and the yield strength or maximum strength is used as the strength of each support member. The initial rigidity is the horizontal rigidity represented by the horizontal load required to cause a unit horizontal displacement. The yield strength is represented by the horizontal load indicating the yield point at which the deformation of the support member changes from elastic deformation to plastic deformation. The maximum strength is represented by the maximum value of the horizontal load in the load-displacement curve.

[0044] Hereinafter, for the initial stiffness A1, yield strength B1, and maximum strength C1 of the specific support member 4 shown in the load-displacement curve E1, the initial stiffness A1 will be referred to as "stiffness A1", and the yield strength B1 and maximum strength C1 will be referred to as "strengths B1, C1". Similarly, for the initial stiffness A2, yield strength B2, and maximum strength C2 of the reference support member 3 shown in the load-displacement curve E2, the initial stiffness A2 will be referred to as "stiffness A2", and the yield strength B2 and maximum strength C2 will be referred to as "strengths B2, C2". Also, for the initial stiffness A3, yield strength B3, and maximum strength C3 of the conventional support member shown in the load-displacement curve E3, the initial stiffness A3 will be referred to as "stiffness A3", and the yield strength B3 and maximum strength C3 will be referred to as "strengths B3, C3".

[0045] As the cross-sectional area of ​​the specific support member 4 increases relative to the reference support member 3, the stiffness A1 and strengths B1, C1 of the specific support member 4 increase and become greater than the stiffness A2 and strengths B2, C2 of the reference support member 3. Also, as the cross-sectional area of ​​the conventional support member increases relative to the reference support member 3, the stiffness A3 and strengths B3, C3 of the conventional support member increase and become greater than the stiffness A2 and strengths B2, C2 of the reference support member 3.

[0046] Comparing the specific support member 4 with the conventional support member, the rigidity A1 of the specific support member 4 is smaller than the rigidity A3 of the conventional support member, and the strengths B1, C1 of the specific support member 4 are approximately the same as the strengths B3, C3 of the conventional support member. In other words, when focusing on the rate of increase in rigidity and strength according to an increase in cross-sectional area relative to the standard support member 3, the rate of increase in strengths B1, C1 of the specific support member 4 relative to the strengths B2, C2 of the standard support member 3 is approximately the same as the rate of increase in strengths B3, C3 of the conventional support member. On the other hand, the rate of increase in rigidity A1 of the specific support member 4 relative to the rigidity A2 of the standard support member 3 is smaller than the rate of increase in rigidity A3 of the conventional support member.

[0047] As shown in Fig. 2, when a horizontal load P such as an earthquake force is applied to the building structure 1, the standard support member 3 and the specific support member 4, which have different rigidity according to the difference in the cross-sectional area, cooperate to resist the horizontal load P. The horizontal load P applied to the building structure 1 is distributed to each of the standard support member 3 and the specific support member 4 according to the rigidity of each of them. When the horizontal load P applied to the building structure 1 is distributed to each of the standard support member 3 and the specific support member 4, the horizontal load P1 distributed to the specific support member 4 with higher rigidity and borne by the specific support member 4 is greater than the horizontal load P2 borne by the standard support member 3.

[0048] Here, when a horizontal load P is applied to the building structure 1, in the first H-shaped steel 41 and the second H-shaped steel 42 constituting the specific support member 4, the largest bending moment M acts on one axial end 4A and the other axial end 4B rigidly joined to the first and second joined members 2A, 2B, and the bending moment M becomes smaller as it approaches the axial center point 4C. In consideration of this point, in the specific support member 4, the first inner flange 411A of the first H-shaped steel 41 and the second inner flange 421A of the second H-shaped steel 42 are not joined in the non-welded region 4C1 including the axial center point 4C, so that a first welded portion 5A is formed in the first welded region 4A1 on the axial one end 4A side relative to the non-welded region 4C1, and a second welded portion 5B is formed in the second welded region 4B1 on the axial other end 4B side. By forming the first welded portion 5A and the second welded portion 5B in the first welded portion 4A1 and the second welded portion 4B1 where a large bending moment M acts, the strengths B1 and C1 required to resist the horizontal load P1 borne by the specific support member 4 can be secured.

[0049] Moreover, in the specific support member 4, the non-welded region 4C1 including the axial center point 4C where the bending moment M acting is small is a region where no weld is formed. This makes it possible to suppress the increase rate of the stiffness A1 from being excessively larger than the strengths B1 and C1 in terms of the increase rate of the stiffness A1 and the strengths B1 and C1 in accordance with the formation of the welds 5A and 5B on both sides of the non-welded region 4C1 in the specific support member 4. That is, in the specific support member 4, the decrease rate of the stiffness A1 is larger than the strengths B1 and C1 in accordance with the non-welded region 4C1. Therefore, it is possible to lower the stiffness A1 of the specific support member 4 while ensuring the strengths B1 and C1 on both sides of the non-welded region 4C1 in the specific support member 4. As a result, when the horizontal load P applied to the building structure 1 is distributed to each support member 3 and 4 according to the magnitude of each of the stiffnesses of the standard support member 3 and the specific support member 4, it is possible to suppress the horizontal load P1 borne by the specific support member 4 from being excessively larger than the horizontal load P2 borne by the standard support member 3. As a result, the horizontal load P is distributed according to the magnitude of the resistance strengths B1, C1 of the specific support members 4 and the resistance strengths B2, C2 of the standard support members 3, which prevents the specific support members 4 from undergoing plastic deformation earlier than the standard support members 3, and the resistance strengths B1, C1 of the specific support members 4 and the resistance strengths B2, C2 of the standard support members 3 can be effectively utilized to resist the horizontal load P, thereby improving the earthquake resistance of the building structure 1.

[0050] In addition, since the horizontal load P1 borne by the specific support member 4 can be prevented from becoming excessively large relative to the horizontal load P2 borne by the reference support member 3, in the first joinable member 2A and the second joinable member 2B, the load on the area supporting the specific support member 4 can be prevented from becoming excessively large relative to the area supporting the reference support member 3.

[0051] As described above, when a horizontal load P is applied to the building structure 1, the largest bending moment M acts on one end 4A and the other end 4B of the first H-shaped steel 41 and the second H-shaped steel 42 constituting the specific support member 4. Therefore, in the first H-shaped steel 41 and the second H-shaped steel 42, when the horizontal load P1 borne by the specific support member 4 exceeds the yield strength B1 of the specific support member 4, plasticization gradually progresses from the one end 4A and the other end 4B toward the center point 4C. In order to suppress the progress of such plasticization, it is desirable to form the first welded portion 5A and the second welded portion 5B in the range where plasticization is expected.

[0052] Therefore, as shown in FIG. 6, in the first H-shaped steel 41 and the second H-shaped steel 42, the region length L21 in the axial direction of the first welded region 4A1 on the one end 4A side with respect to the non-welded region 4C1 is set so that the first plasticization assumed region 4D1 is included in the first welded region 4A1. The first plasticization assumed region 4D1 is a region where plasticization is assumed around the one end 4A of the first H-shaped steel 41 and the second H-shaped steel 42. Similarly, the region length L22 in the axial direction of the second welded region 4B1 on the other end 4B side with respect to the non-welded region 4C1 is set so that the second plasticization assumed region 4D2 is included in the second welded region 4B1. The second plasticization assumed region 4D2 is a region where plasticization is assumed around the other end 4B of the first H-shaped steel 41 and the second H-shaped steel 42.

[0053] In the first H-shaped steel 41 and the second H-shaped steel 42, the region length L31 in the axial direction of the first plasticization assumed region 4D1 and the region length L32 in the axial direction of the second plasticization assumed region 4D2 can be calculated based on the total length L1 of the specific support member 4 in the axial direction from one end 4A to the other end 4B, or the width dimension W1 in the width direction perpendicular to the axial direction of the specific support member 4. The region length L31 of the first plasticization assumed region 4D1 and the region length L32 of the second plasticization assumed region 4D2 are set to, for example, at least one-tenth the length of the total length L1 of the specific support member 4, or at least twice the length of the width dimension W1 of the specific support member 4.

[0054] The region length L21 of the first welding region 4A1 is not particularly limited as long as it is set so that the first plasticization assumed region 4D1 is included in the first welding region 4A1. The region length L21 of the first welding region 4A1 is set to, for example, a quarter of the total length L1 of the specific support member 4. Similarly, the region length L22 of the second welding region 4B1 is not particularly limited as long as it is set so that the second plasticization assumed region 4D2 is included in the second welding region 4B1. The region length L22 of the second welding region 4B1 is set to, for example, a quarter of the total length L1 of the specific support member 4. In this case, the region length L23 in the axial direction of the non-welded region 4C1 between the first welding region 4A1 and the second welding region 4B1 is set to a half of the total length L1 of the specific support member 4.

[0055] In this embodiment, as shown in FIG. 6, the first welded portion 5A is formed in the first welding region 4A1 including one end 4A in the axial direction of the first H-shaped steel 41 and the second H-shaped steel 42. That is, in the first welding region 4A1, the first welded portion 5A extends in a continuous straight line from one end 4A in the axial direction of the first H-shaped steel 41 and the second H-shaped steel 42 toward the center point 4C. Similarly, in the second welding region 4B1, the second welded portion 5B is formed including the other end 4B in the axial direction of the first H-shaped steel 41 and the second H-shaped steel 42. That is, in the second welding region 4B1, the second welded portion 5B extends in a continuous straight line from the other end 4B in the axial direction of the first H-shaped steel 41 and the second H-shaped steel 42 toward the center point 4C. In this way, in the first H-shaped steel 41 and the second H-shaped steel 42, the first welded portion 5A and the second welded portion 5B are formed including the axial end 4A and the other end 4B where the largest bending moment M acts, so that the strengths B1, C1 required to resist the horizontal load P1 borne by the specific support member 4 can be more reliably secured.

[0056] In addition, in the first welding region 4A1, the first welded portion 5A is continuously formed over the entire axial direction of the first welding region 4A1. In this case, the weld length L21A in the axial direction of the first welded portion 5A is the same as the region length L21 of the first welding region 4A1. Similarly, in the second welding region 4B1, the second welded portion 5B is continuously formed over the entire axial direction of the second welding region 4B1. In this case, the weld length L22A in the axial direction of the second welded portion 5B is the same as the region length L22 of the second welding region 4B1. In this way, in the first H-shaped steel 41 and the second H-shaped steel 42, the first welded portion 5A and the second welded portion 5B are continuously formed over the entire welding regions 4A1, 4B1 on the one end 4A side and the other end 4B side in the axial direction where the large bending moment M acts, so that the strengths B1, C1 required to resist the horizontal load P1 borne by the specific support member 4 can be more reliably secured.

[0057] In the first H-shaped steel 41 and the second H-shaped steel 42, the first welded portion 5A formed in the first welding region 4A1 and the second welded portion 5B formed in the second welding region 4B1 are formed to be symmetrical in the axial direction. This allows the specific support member 4 to support the horizontal load P evenly at each of the one end 4A and the other end 4B in the axial direction.

[0058] As described above, the first through hole 412A is formed in the first web 412 of the first H-shaped steel 41, and the second through hole 422A is formed in the second web 422 of the second H-shaped steel 42. The first through hole 412A is formed in at least the first welded region 4A1 and the second welded region 4B1 on both sides of the non-welded region 4C1 in the first web 412. That is, the first through hole 412A may be formed in each of the non-welded region 4C1, the first welded region 4A1, and the second welded region 4B1 in the first web 412, or may be formed only in the first welded region 4A1 and the second welded region 4B1. Similarly, the second through hole 422A is formed in at least the first welded region 4A1 and the second welded region 4B1 on both sides of the non-welded region 4C1 in the second web 422.

[0059] When a horizontal load P is applied to the building structure 1, there is a risk that plastic deformation may easily occur around the first through hole 412A and the second through hole 422A in the first H-shaped steel 41 and the second H-shaped steel 42. Therefore, in the first welding region 4A1, the first welded portion 5A is formed in a range that covers at least half (preferably the entirety) of the first through hole 412A and the second through hole 422A arranged in the first welding region 4A1 when viewed from a direction perpendicular to the axial direction. Similarly, in the second welding region 4B1, the second welded portion 5B is formed in a range that covers at least half (preferably the entirety) of the first through hole 412A and the second through hole 422A arranged in the second welding region 4B1 when viewed from a direction perpendicular to the axial direction. This makes it possible to suppress the occurrence of plastic deformation around the first through hole 412A and the second through hole 422A.

[0060] In this embodiment, the weld length L21A of the first welded portion 5A and the weld length L22A of the second welded portion 5B are set so that the rigidity ratio AR and the yield strength ratio BR are approximately equal. Specifically, the weld length L21A of the first welded portion 5A and the weld length L22A of the second welded portion 5B are set so that the rigidity ratio AR and the yield strength ratio BR satisfy, for example, the following formula (1). 1≦(stiffness ratio AR / strength ratio BR)≦1.5 (1)

[0061] The stiffness ratio AR indicates the ratio (A1 / A2) of the stiffness A1 of the specific support member 4 to the stiffness A2 of the reference support member 3. The strength ratio BR indicates the ratio (B1,C1 / B2,C2) of the strength B1,C1 of the specific support member 4 to the strength B2,C2 of the reference support member 3.

[0062] In addition, if the ratio of the stiffness A3 of the conventional support member to the stiffness A2 of the standard support member 3 is defined as the conventional stiffness ratio, and the ratio of the strengths B3, C3 of the conventional support member to the strengths B2, C2 of the standard support member 3 is defined as the conventional strength ratio, then (conventional stiffness ratio / conventional strength ratio) exceeds 1.5 and does not satisfy the above formula (1).

[0063] As described above, the weld length L21A of the first welded portion 5A and the weld length L22A of the second welded portion 5B are set so that the stiffness ratio AR and the strength ratio BR are substantially equal and satisfy the above formula (1). This makes it possible to more reliably prevent the rate of increase in stiffness A1 from becoming excessively larger than the strengths B1 and C1 in the specific support member 4 relative to the reference support member 3. Therefore, when the horizontal load P applied to the building structure 1 is distributed to each support member 3 and 4 according to the magnitude of each stiffness of the reference support member 3 and the specific support member 4, it is possible to more reliably prevent the horizontal load P1 borne by the specific support member 4 from becoming excessively larger than the horizontal load P2 borne by the reference support member 3.

[0064] Although the building structure 1 according to the embodiment of the present invention has been described above, the present invention is not limited to this, and for example, the following modified embodiments can be adopted.

[0065] In the above embodiment, the first and second H-shaped steels 41 and 42 constituting the specific support member 4 are formed continuously over the entire welded regions 4A1 and 4B1 on the axial one end 4A side and the other end 4B side in the first and second H-shaped steels 41 and 42, respectively, but the present invention is not limited thereto. As shown in FIG. 7, the first and second welded regions 5A and 5B do not have to be formed over the entire first and second welded regions 4A1 and 4B1 in the axial direction. In this case, the weld length L21A of the first welded region 5A is shorter than the region length L21 of the first welded region 4A1, and the weld length L22A of the second welded region 5B is shorter than the region length L22 of the second welded region 4B1.

[0066] In the above embodiment, the first welded portion 5A and the second welded portion 5B are formed including the one end 4A and the other end 4B in the axial direction of the first H-shaped steel 41 and the second H-shaped steel 42 constituting the specific support member 4, but the present invention is not limited to this. As shown in FIG. 8, the first welded portion 5A and the second welded portion 5B may not be formed including the one end 4A and the other end 4B in the axial direction of the first H-shaped steel 41 and the second H-shaped steel 42. In this case, in the first welding region 4A1, the first welded portion 5A extends from a position away from the one end 4A in the axial direction of the first H-shaped steel 41 and the second H-shaped steel 42 toward the center point 4C. Similarly, in the second welding region 4B1, the second welded portion 5B extends from a position away from the other end 4B in the axial direction of the first H-shaped steel 41 and the second H-shaped steel 42 toward the center point 4C.

[0067] In the above embodiment, the first welded portion 5A extends in a continuous straight line in the first welding region 4A1 and the second welded portion 5B extends in a continuous straight line in the second welding region 4B1 in the first H-shaped steel 41 and the second H-shaped steel 42 constituting the specific support member 4, but the present invention is not limited to this. As shown in FIG. 9, the first welded portion 5A may have a plurality of welded portions 5A1 formed at intervals in the axial direction in the first welding region 4A1. Similarly, the second welded portion 5B may have a plurality of welded portions 5B1 formed at intervals in the axial direction in the second welding region 4B1.

[0068] In the above embodiment, the first H-shaped steel 41 and the second H-shaped steel 42 constituting the specific support member 4 are described as having the first through hole 412A formed in the first web 412 and the second through hole 422A formed in the second web 422, but the present invention is not limited to this. The second web 422 does not have to have a through hole. Moreover, each of the first web 412 and the second web 422 does not have to have a through hole. [Explanation of symbols]

[0069] 1. Building structure 2A 1st member to be joined 2B 2nd member to be joined 3 Reference support member 4. Specific support members 41 First H-beam 411A, 411B First flange 412 Web 1 412A 1st through hole 42 Second H-beam 421A, 421B Second flange 422 Second Web 422A 2nd through hole 4A1 First welding area 4B1 Second welding area 4C center point 4C1 Non-welded area (specified area) 5A First Weld 5B Second weld

Claims

1. A reference support member having a predetermined rigidity and supporting a load; A specific support member having a higher rigidity than the reference support member and supporting a load; a first joined member to which one axial end of the reference support member and one axial end of the specific support member are rigidly joined; a second joined member to which the other axial end of the reference support member and the other axial end of the specific support member are rigidly joined, The specific support member is a first H-shaped steel having a pair of first flanges and a first web connecting the first flanges to each other; a second H-shaped steel having a pair of second flanges and a second web connecting the second flanges to each other; one of the pair of first flanges and one of the pair of second flanges are welded to each other by a weld portion with outer surfaces thereof in contact with each other, A building structure, wherein the welded portions are formed only on both sides of a specified region including the axial center points of the first H-shaped steel and the second H-shaped steel, so that one of the pair of first flanges and one of the pair of second flanges are not joined in the specified region including the axial center points of the first H-shaped steel and the second H-shaped steel.

2. The welded portion is A first welded portion formed including one end portion in the axial direction of the first H-shaped steel and the second H-shaped steel; The building structure according to claim 1 , further comprising: a second weld portion formed including the other axial end portion of the first H-shaped steel and the other axial end portion of the second H-shaped steel.

3. The building structure according to claim 1 or 2, wherein the welded portion is formed continuously over the entire areas on both sides of the predetermined area.

4. The building structure according to any one of claims 1 to 3, wherein the welds are formed axially symmetrically on both sides of the specified region.

5. A building structure as described in any one of claims 1 to 4, wherein the axial length of the weld is set so that a rigidity ratio indicating the ratio of the rigidity of the specific support member to the rigidity of the reference support member and a strength ratio indicating the ratio of the strength of the specific support member to the strength of the reference support member are approximately equal.

6. The first web has through holes formed on at least both sides of the predetermined region, the through holes penetrating the first web in a thickness direction thereof, The building structure according to any one of claims 1 to 5, wherein the welded portion is formed in an area that covers at least half of the through hole when viewed from a direction perpendicular to the axial direction.

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