Brace mounting structure

Abstract

To reduce planar dimensions of a base plate.SOLUTION: A brace mounting structure S includes a steel column 4 having a column base 7 formed into a tubular shape, a base plate 17 attached to an underside of the steel column, a gusset plate 10 attached to the column base of the steel column and the base plate, and a brace 8 attached to the gusset plate. A gap through which the gusset plate is inserted is provided in the column base of the steel column, and the gusset plate inserted into the gap is welded to the base plate inside the column base of the steel column.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a brace attachment structure.

Background Art

[0002] Generally, in a steel-frame building, it is widely practiced to attach the end of a brace to the column base of a steel column. In this case, a base plate is attached to the lower surface of the steel column, and a gusset plate is attached to the column base of the steel column and the base plate. The end of the brace is attached to this gusset plate.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Generally, a gusset plate is attached by welding to the outer surface of the column base of a steel column and the upper surface of a base plate that protrudes horizontally from the column base of the steel column.

[0005] However, in order to ensure the welding length between the gusset plate and the base plate, there is a problem that the planar dimensions of the base plate increase. If the base plate becomes larger, the planar dimensions of the foundation column to which it is attached also become larger, and there is a risk of increasing the construction cost.

[0006] Therefore, in view of such circumstances, the present disclosure was devised, and its object is to provide a brace attachment structure capable of reducing the planar dimensions of the base plate.

Means for Solving the Problems

[0007] According to one aspect of the present disclosure, a steel column in which the column base is formed in a tubular shape, and A base plate attached to the lower surface portion of the steel column, a gusset plate attached to the column base portion of the steel column and the base plate, and a brace attached to the gusset plate, are provided, a gap through which the gusset plate is inserted is provided in the column base portion of the steel column, and the gusset plate inserted into the gap is welded to the base plate inside the column base portion of the steel column. A brace mounting structure is provided, which is characterized by the above.

[0008] Preferably, the gaps are provided on two opposing surfaces of the column base portion of the steel column, the gusset plate is inserted into the two gaps and penetrates the column base portion of the steel column.

[0009] Preferably, a mounting portion of the brace is provided at one end of the gusset plate protruding from the column base portion of the steel column.

[0010] Preferably, mounting portions of the brace are provided at both ends of the gusset plate protruding from the column base portion of the steel column.

[0011] Preferably, the column base portion of the steel column is composed of two split pieces split longitudinally, and the gap is provided between the two split pieces.

[0012] Preferably, the two split pieces are formed by splitting a steel pipe into two.

[0013] Preferably, a through diaphragm is welded to the upper end face portions of the two split pieces and the upper end face portion of the gusset plate.

Advantages of the Invention

[0014] According to the present disclosure, the planar dimensions of the base plate can be reduced.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

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Figure 10

Figure 11

Modes for Carrying Out the Invention

[0016] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. Note that it should be noted that the present disclosure is not limited to the following embodiments.

[0017] FIG. 1 is a schematic front view showing a part of a building according to this embodiment. The building 1 has a building main body 2 as its superstructure and a foundation structure 3 as its substructure, and the foundation structure 3 supports the building main body 2 from below. The building 1 is a building with a relatively small number of columns and partition walls per floor area and has a clean and wide floor surface, and is used, for example, as a logistics warehouse or a factory. However, the building 1 may be used for other purposes. The foundation structure 3 is made of reinforced concrete and almost all of it is buried in the ground. The building main body 2 is made of steel frame.

[0018] Define the front-back, left-right, up-down directions as shown in the figure. In the figure, the right side is the right side, the left side is the left side, the upper side is the upper side, the lower side is the lower side, the front side of the paper thickness direction of the figure is the rear side, and the back side is the front side. The front-back direction and the left-right direction are included in the horizontal direction, and the up-down direction coincides with the vertical direction.

[0019] The building main body 2 has a plurality of steel columns 4 extending in the up-down direction, a plurality of steel beams 5 connecting predetermined height portions of the steel columns 4 to each other, and walls 6 provided along the plurality of steel columns 4 and steel beams 5. The building main body 2 also has cross braces or braces 8 connecting the lower end portions or column feet 7 of the steel columns 4 and the steel beams 5.

[0020] As shown in the figure, the left and right braces 8 are arranged in an inverted V shape, connecting the middle part of the steel beam 5 and the column feet 7 of the steel columns 4 respectively. A gusset plate 9 for attaching the upper end portions of the left and right braces 8 is attached to the middle part of the steel beam 5. Gusset plates 10 for attaching the lower end portions of the left and right braces 8 are also attached to the column feet 7 of the left and right steel columns 4 respectively.

[0021] In the case of the illustrated figure, a steel column 4, a steel beam 5, and a brace 8 are arranged at a rear position relatively close to the wall 6. An opening 11 used as an entrance / exit is provided in the wall 6. The opening 11 is arranged in an open space below and between the left and right braces 8. By arranging the left and right braces 8 in an inverted V shape, a space with a relatively large left - right width is formed below these braces 8. Therefore, by forming the opening 11 in this space, an opening 11 with a large left - right width can be formed. This is very advantageous for providing an entrance / exit through which large vehicles such as trucks can enter and exit, for example.

[0022] Normally, an opening 11 is not formed at the position where the steel column 4 or the brace 8 is located because it would obstruct entry and exit.

[0023] The foundation structure 3 has a plurality of foundation footings 12, a plurality of foundation columns 13 rising from the foundation footings 12, a plurality of foundation girders 14 connecting the foundation footings 12 and the foundation columns 13 to each other, and a slab 15 formed on the upper surface portions of the foundation columns 13 and the foundation girders 14. In the illustrated example, the slab 15 is omitted, and only the position of its upper surface is indicated by a virtual line.

[0024] The steel column 4 is placed on the foundation column 13, and the steel column 4 is supported from below by the foundation column 13. A plurality of anchor bolts 16 project upward from the foundation column 13, and using these anchor bolts 16, a base plate 17 attached to the lower surface portion of the steel column 4 is fixed. In this way, the column base portion 7 of the steel column 4 is an exposed column base.

[0025] Next, a structure for attaching the brace 8 to the steel column 4, that is, the brace attachment structure S, will be described. The brace attachment structure S exists for each of the left and right steel columns 4 as shown in FIG. 1. Since these brace attachment structures S are symmetric about the left - right axis, only the one on the left side will be described in detail here, and the description of the one on the right side will be omitted.

[0026] FIG. 2 is a front view showing the left brace mounting structure S. FIG. 3 is a schematic cross-sectional plan view of the brace mounting structure S, which is a cross-sectional view taken along line III-III of FIG. 2.

[0027] As shown in FIGS. 2 and 3, the brace mounting structure S includes a steel column 4 with a column base portion 7 formed in a tubular shape, a base plate 17 attached to the lower surface portion of the steel column 4, a gusset plate 10 attached to the column base portion 7 of the steel column 4 and the base plate 17, and a brace 8 attached to the gusset plate 10. A gap 18 through which the gusset plate 10 is inserted is provided in the column base portion 7 of the steel column 4. The gusset plate 10 inserted through the gap 18 is welded to the base plate 17 inside the column base portion 7 of the steel column 4.

[0028] The foundation column 13 is formed in a quadrangular or substantially square shape in plan view, and the foundation girders 14 are joined to the front, rear, left, and right side surfaces thereof. The height positions of the upper ends of the foundation column 13 and the foundation girders 14 are made equal. A plurality of anchor bolts 16 are embedded inside and on the outer periphery of the foundation column 13, and these anchor bolts 16 protrude upward from the foundation column 13. Intermediate nuts 19 are attached to the anchor bolts 16, and a plate that supports and connects them to prevent displacement of the anchor bolts 16 is removed after the concrete is placed. The height positions of the intermediate nuts 19 and the upper surface of the foundation column 13 are made equal. The lower end portions of the anchor bolts 16 are embedded in the foundation footing 12 (see FIG. 1).

[0029] The base plate 17 is overlapped and placed on the upper surface portion of the foundation column 13 with an intervening member 20 composed of top mortar, spacers, etc. sandwiched therebetween. At this time, the anchor bolts 16 penetrate or are inserted through the intervening member 20 and are inserted through a plurality of anchor bolt holes 21 in the base plate 17.

[0030] Washers 22 are fitted onto the anchor bolts 16 protruding above the base plate 17, and fixing nuts 23 are tightened. Finally, lock nuts 24 are tightened to complete the fixing of the base plate 17 to the foundation column 13 and thus the column base portion 7 of the steel column.

[0031] The planar shapes of the intervening member 20, the base plate 17, and the steel frame column base portion 7 are a quadrangle or a substantially square shape similar to that of the foundation column 13.

[0032] The steel frame column 4 integrally has a column base portion 7 to which the base plate 17 and the gusset plate 10 are attached by welding, a continuous diaphragm 25 attached by welding to the upper surface portion of the column base portion 7, and an upper portion 26 attached by welding to the upper surface portion of the continuous diaphragm 25.

[0033] As shown in FIG. 4, the upper portion 26 is formed of a square steel pipe having a quadrangular or substantially square cross-sectional shape in plan view. The continuous diaphragm 25 is formed of a steel plate having a quadrangular or substantially square planar shape and completely partitions between the upper portion 26 and the column base portion 7. The front-rear width and the left-right width of the continuous diaphragm 25 are made larger than those of the upper portion 26 and the column base portion 7. The front, rear, left, and right end portions of the continuous diaphragm 25 protrude in the horizontal direction from the upper portion 26 and the column base portion 7.

[0034] The column base portion 7 is composed of two divided pieces divided in a vertically split state, that is, a rear divided piece 27 and a front divided piece 28. And the gap 18 is provided between these two divided pieces 27, 28. These divided pieces 27, 28 have a shape that is symmetric front-rear and symmetric left-right.

[0035] On two opposing surfaces of the column base portion 7 of the steel frame column 4, that is, the right side surface 29 and the left side surface 30, gaps 18 with a constant interval extending in the vertical direction over the entire height of the column base portion 7 are provided. The gusset plate 25 is inserted into these two gaps 18 and penetrates the column base portion 7 of the steel frame column 4. The interval of the gap 18 is made slightly larger than the thickness t1 of the gusset plate 25.

[0036] As can be seen by comparing FIGS. 3 and 4, the cross-sectional shape of the column base portion 7 in plan view is made equal to the cross-sectional shape of the upper portion 26, except for the portion of the gap 18 and except for the point where it is divided into two divided pieces 27, 28. The left-right width B1L of the column base portion 7 is made equal to the left-right width B1H of the upper portion 26, and the front-rear width B2L of the column base portion 7 is made equal to the front-rear width B2H of the upper portion 26. The plate thickness t2L of the column base portion 7 is also made equal to the plate thickness t2H of the upper portion 26. In the assembled state, the upper portion 26 and the column base portion 7 are coaxially positioned, and the plate thickness portions or the meat portions of both are positioned at the same horizontal position.

[0037] The two divided pieces 27, 28 are formed by dividing a steel pipe into two. In particular, the two divided pieces 27, 28 are formed in a U-shaped in plan view by dividing the same square steel pipe as the upper portion 26 into two. Specifically, machining or the like is performed on the portion of the gap 18 of the divided piece formed by dividing the square steel pipe into two, and sizing is performed so that the cross-sectional shape is substantially equal to that of the upper portion 26 when assembled, and the two divided pieces 27, 28 are formed. Thereby, the divided pieces 27, 28 can be formed using the same square steel pipe as the upper portion 26 as a material.

[0038] FIG. 5 shows a cross-sectional view when the rear divided piece 27 is removed to make the gusset plate 10 visible. As can also be seen from this figure, the gusset plate 10 is a pentagonal plate-like member extending in the vertical and horizontal directions. The gusset plate 10 has a lower end surface portion 31 welded to the upper surface portion of the base plate 17 and an upper end surface portion 32 welded to the lower surface portion of the through diaphragm 25. The height of the gusset plate 10 is made equal to the height of the divided pieces 27, 28.

[0039] The left end portion of the gusset plate 10 protrudes from the inside of the column base portion 7 to the outside of the column base portion 7 by a minute predetermined length L1 through the left gap 18.

[0040] On one side, the right end portion of the gusset plate 10 also protrudes from inside the column base portion 7 to outside the column base portion 7 through the right gap 18. However, the protruding length L2 is larger than the left protruding length L1. An attachment portion 33 of the brace 8 is provided on this right protruding portion. In other words, the protruding portion forms the attachment portion 33. Thus, the attachment portion 33 of the brace 8 is provided at one end (right end portion) in the left-right direction of the gusset plate 10 protruding from the column base portion 7 of the steel column 4.

[0041] The lower end face portion 34 of the attachment portion 33, which is a part of the lower end face portion 31, extends toward the right up to the position of the rightmost end of the upper face portion of the base plate 17. Thereby, the welding length of the gusset plate 10 with respect to the upper face portion of the base plate 17 can be increased. The central axis C1 of the brace 8 is inclined at an angle θ1 with respect to the left-right direction. In accordance with the direction of this central axis C1, a plurality of bolt insertion holes 35 are provided in the attachment portion 33 in a staggered pattern.

[0042] Vertical plates 36 protruding toward the rear side and the front side respectively are integrally attached to the attachment portion 33 by welding. Thereby, the attachment portion 33 and the vertical plates 36 form a cross-sectional shape when viewed from the direction of the axis C1. A plurality of bolt insertion holes 37 similar to the above are also provided in the vertical plates 36. Note that only the central positions of the bolt insertion holes 37 in the vertical plates 36 are indicated by dashed-dotted lines.

[0043] The upper end face portion 38 of the attachment portion 33 (referred to as the attachment portion upper end face portion 38) is also a part of the upper end face portion 32. The attachment portion upper end face portion 38 and the through diaphragm 25 extend toward the right up to approximately the same position as the lower end face portion 34. That is, the right end portions of the gusset plate 10 and the through diaphragm 25 are larger than the left end portions and protrude in the left-right direction from the column base portion 7 of the steel column 4. Thereby, the welding length of the gusset plate 10 with respect to the lower face portion of the through diaphragm 25 can be increased.

[0044] The gusset plate 10 has a right upper end face portion 39 that slopes downward and to the right from the right end of the upper end face portion of the mounting portion 38, and a right lower end face portion 40 that slopes upward and to the right from the right end of the lower end face portion 34. The right upper end face portion 39 is perpendicular to the direction of axis C1, and the right lower end face portion 40 slopes at an angle θ2 that is slightly larger than the direction of axis C1 with respect to the left-right direction. The intersection of the right upper end face portion 39 and the right lower end face portion 40 forms the rightmost end portion of the gusset plate 10.

[0045] A reinforcing plate 41 perpendicular to this is welded to the right lower end face portion 40. The lower end of the reinforcing plate 41 is also welded to the base plate 17. By providing such a reinforcing plate 41, the rigidity of the mounting portion 33 can be increased.

[0046] The lower end joint portion 42 of the brace 8 has a cross-shaped cross-section similar to the cross-sectional shape of the mounting portion 33 including the vertical plate 36 and has a plurality of bolt insertion holes. The lower end joint portion 42 of the brace 8 and the mounting portion 33 are butted against each other in a state where they are close to each other. A connecting plate 44 having a plurality of bolt insertion holes 43 that match the bolt insertion holes of both is overlapped on the front and back surfaces of each plate at the lower end joint portion 42 of the brace 8 and the mounting portion 33 including the vertical plate 36. A high-tensile bolt (not shown) is inserted through these bolt insertion holes in a penetrating state, and a nut (not shown) is tightened on the high-tensile bolt. As a result, the lower end joint portion 42 of the brace 8 is firmly connected to the gusset plate 10.

[0047] Next, an example of the method for assembling the steel column 4, the base plate 17, and the gusset plate 10 will be described.

[0048] First, the gusset plate 10 is placed and positioned on the base plate 17, and the gusset plate 10 is welded and joined to the base plate 17.

[0049] Next, the through diaphragm 25 is placed and positioned on the gusset plate 10, and the through diaphragm 25 is welded and joined to the gusset plate 10.

[0050] Next, front and rear split pieces 27 and 28 are inserted between the base plate 17 and the through diaphragm 25, and the gusset plate 10 is sandwiched between the front and rear split pieces 27 and 28. In this state, the front and rear split pieces 27 and 28 are welded and joined to the base plate 17, the gusset plate 10, and the through diaphragm 25.

[0051] Then, the upper part 26 of the steel column 4 is placed and positioned on the through diaphragm 25, and the upper part 26 of the steel column 4 is welded and joined to the through diaphragm 25.

[0052] Thereby, the upper part 26 of the steel column 4, the through diaphragm 25, the front and rear split pieces 27 and 28, the gusset plate 10, and the base plate 17 are integrated, and a steel column unit is formed.

[0053] The production of this steel column unit is preferably carried out in a factory. Thereby, the steel column unit can be manufactured more accurately and easily than when carried out at the construction site. The steel column unit manufactured in the factory is transported to the construction site by a vehicle such as a truck.

[0054] FIG. 6 is a cross-sectional plan view showing an enlarged view of the welded portion of the front and rear split pieces 27 and 28. As shown in the figure, the split pieces 27 and 28 are fillet welded to the gusset plate 10 from the outer or front side. An open groove 45 that opens outward is provided at the butting edge portion of the split pieces 27 and 28. A backing plate 46 is pre-welded to the back surface portion of the split pieces 27 and 28 to prevent the melted material from flowing into the back side during welding. After welding, the open groove 45 of the front and rear split pieces 27 and 28 and the gusset plate 10 are fixed by a weld bead 47.

[0055] FIG. 7 is a cross-sectional view taken along line VII-VII of FIG. 1, and the height position of this cross-section is the same as the height position of the cross-sectional view in FIG. 3 (cross-sectional view taken along line III-III of FIG. 2). As shown in the figure, the left and right gusset plates 10 are arranged symmetrically.

[0056] Next, the advantages of this embodiment will be described.

[0057] FIG. 8 and FIG. 9 are a front view and a cross-sectional plan view showing a comparative example to be compared with the present embodiment, and correspond to FIG. 2 and FIG. 3, respectively. For convenience, the same parts as those in the basic embodiment are denoted by the same reference numerals in the drawings and the description thereof is omitted, and hereinafter, the differences from the basic embodiment will be mainly described.

[0058] In the case of the comparative example, although the column base portion 7 of the steel column 4 is formed in a square tubular shape having the same cross-sectional shape as the upper portion 26, no gap through which the gusset plate 10 is inserted is provided. The gusset plate 10 is disposed only outside the column base portion 7 and is fillet-welded to the column base portion 7, the continuous diaphragm 25, and the base plate 17. Note that the inclination angle θ2 of the lower right end face portion 40 is made slightly larger than that in the basic embodiment.

[0059] In this case, in order to secure the necessary welding length between the gusset plate 10 and the base plate 17, the length of the base plate 17 protruding to the right from the column base portion 7 of the steel column 4 is made larger than that in the basic embodiment. And in order to transmit the stress evenly, the length of the base plate 17 protruding to the left from the column base portion 7 of the steel column 4 is also made larger than that in the basic embodiment and is made equal to the length of the base plate 17 protruding to the right.

[0060] As a result, the left-right width B3 of the base plate 17 is made larger in the comparative example than in the basic embodiment. And the base plate 17 in the comparative example is formed in a rectangular shape in plan view in which the left-right width B3 is clearly larger than the front-rear width B4.

[0061] Correspondingly, the left-right width of the foundation column 13 that supports the base plate 17 is also made larger in the comparative example than in the basic embodiment. And the foundation column 13 in the comparative example is also formed in a rectangular shape in plan view in which the left-right width is clearly larger than the front-rear width.

[0062] In this way, since the dimensions of the base plate 17 in plan view increase, and accordingly the dimensions of the foundation column 13 in plan view increase, there is a possibility that the construction cost increases.

[0063] On the one hand, in this embodiment, a gap 18 is provided in the column base portion 7 of the steel column 4, and the gusset plate 10 is inserted into this gap 18. Also, the gusset plate 10 is welded to the base plate 17 inside the column base portion 7 of the steel column 4. Therefore, a welding length can be ensured inside the column base portion 7, and accordingly, the left - right width B3 of the base plate 17 can be reduced and made smaller than in the comparative example. Along with this, the left - right width of the foundation column 13 can also be reduced and made smaller than in the comparative example.

[0064] Therefore, according to this embodiment, the planar dimension of the base plate 17 can be reduced, and by extension, the planar dimension of the foundation column 13 can also be reduced, thus suppressing the construction cost.

[0065] Also, in this embodiment, since the gusset plate 10 is welded to the base plate 17 inside the column base portion 7 of the steel column 4, the gusset plate 10 can be welded to the base plate 17 deeper inside the steel column 4 than in the comparative example. Therefore, the tensile axial force generated in the brace 8 can be efficiently dispersed and transmitted to more anchor bolts 16 via the gusset plate 10 and the base plate 17. Therefore, the burden on the anchor bolts 16 is reduced, which is advantageous for reducing their number.

[0066] Particularly, in the case of a building 1 used as a logistics warehouse or a factory as in this embodiment, generally the loading load is large and there are also restrictions on the arrangement of the braces 8. For example, the brace 8 can only be arranged where there is no wall. Therefore, the tensile axial force borne by each brace 8 tends to be large.

[0067] However, in this embodiment, even if the tensile axial force of the brace 8 increases, it can be efficiently dispersed and transmitted to more anchor bolts 16. Therefore, the burden on the anchor bolts 16 is reduced, which is advantageous for reducing their number.

[0068] In this embodiment, gaps 18 are provided on two opposing surfaces (right side surface 29 and left side surface 30) of the column base portion 7 of the steel column 4. The gusset plate 25 is inserted into these two gaps 18 and penetrates the column base portion 7 of the steel column 4.

[0069] Thereby, the gusset plate 25 can be welded to the two opposing surfaces, and the gusset plate 25 can be firmly attached to the column base portion 7.

[0070] In this embodiment, the column base portion 7 of the steel column 4 is composed of two split pieces 27 and 28 that are split longitudinally, and a gap 18 is provided between these two split pieces 27 and 28. Thereby, as described in the above assembly method, the assembly of the column base portion 7 and the gusset plate 25 can be easily assembled.

[0071] In this embodiment, the two split pieces 27 and 28 are formed by splitting a steel pipe into two. Thereby, the split pieces 27 and 28 can be formed using general-purpose materials, and the manufacturing cost can be suppressed. In particular, the two split pieces 27 and 28 are formed by splitting the same square steel pipe as the upper part 26 into two. Thereby, the manufacturing cost can be further suppressed.

[0072] In this embodiment, the continuous diaphragm 25 is welded and attached to the upper end face portions of the two split pieces 27 and 28 and the upper end face portion 32 of the gusset plate 10. Thereby, the assembly of the split pieces 27 and 28 and the gusset plate 10 can be further strengthened. Note that the rigidity of the column base portion can be increased by the continuous diaphragm 25.

[0073] In this embodiment, the cross-sectional shape of the column base portion 7 is made substantially equal to the cross-sectional shape of the upper part 26 except for the portion of the gap 18. Therefore, the vertical load of the upper part 26 can be directly transmitted to the column base portion 7.

[0074] As described above in detail, the embodiments of the present disclosure have been described in detail, but various other embodiments and modifications of the present disclosure can be considered.

[0075] (1) Figures 10 and 11 show modified examples. For convenience, the rear split piece 27 located on the front side in the paper thickness direction in Figure 10 is omitted. In this modified example, mounting portions 33 for attaching the brace 8 are provided not only at the right end portion but also at the left end portion of the gusset plate 10. That is, the mounting portions 33 of the brace 8 are provided at both end portions of the gusset plate 10 protruding in the left - right direction from the column base portion 7 of the steel column 4. Since the mounting portion 33 at the left end is symmetric with the mounting portion 33 at the right end in the left - right direction, detailed description thereof is omitted. The left - hand brace 8 attached to the mounting portion 33 at the left end is also symmetric with the right - hand brace 8 in the left - right direction.

[0076] Also in this case, inside the column base portion 7 of the steel column 4, the welding length between the gusset plate 10 and the base plate 17 is ensured. Therefore, there is no need to extend the base plate 17 to the left, and the left - right width B3 of the base plate 17 can be made equal to that of the basic embodiment. And the left - right width of the foundation column 13 can also be made equal to that of the basic embodiment, and as a result, the construction cost can be suppressed.

[0077] (2) The column base portion 7 of the steel column 4 may be composed of more than two split pieces divided in a vertically split state. And these split pieces may be welded and assembled into a configuration like the basic embodiment.

[0078] (3) The two split pieces 27 and 28 constituting the column base portion 7 may be formed by bending a flat iron plate into a U - shape by press working or the like.

[0079] (4) The cross - sectional shape of the column base portion 7 of the steel column 4 does not necessarily have to be the same as the cross - sectional shape of the upper portion 26. The key is that the vertical load of the upper portion 26 can be directly transmitted to the column base portion 7. If such requirements are met, the cross - sectional shape of the column base portion 7 can be appropriately changed. For example, while making the inner cross - sectional shape of the column base portion 7 the same as the inner cross - sectional shape of the upper portion 26, the plate thickness of the column base portion 7 can be made larger than the plate thickness of the upper portion 26, and the outer cross - sectional shape of the column base portion 7 can be made larger than the outer cross - sectional shape of the upper portion 26.

[0080] Alternatively, conversely, while making the outer cross-sectional shapes of the column base portion 7 and the upper portion 26 equal, the inner cross-sectional shape of the column base portion 7 may be made smaller than the inner cross-sectional shape of the upper portion 26.

[0081] Combining both, the outer cross-sectional shape of the column base portion 7 may be made larger than the outer cross-sectional shape of the upper portion 26, and the inner cross-sectional shape of the column base portion 7 may be made smaller than the inner cross-sectional shape of the upper portion 26.

[0082] (5) The configuration of the lower end joint portion 42 of the brace 8 and the attachment portion 33 to which it is attached is not limited to the above configuration, and can be changed to various other configurations including known ones.

[0083] (6) The cross-sectional shape of the steel column 4 does not have to be rectangular, and may be, for example, circular or the like. Also, the cross-sectional shapes of the upper portion 26 and the column base portion 7 may be different. The continuous diaphragm 25 may be omitted.

[0084] (7) The height position of the upper end of the foundation column 13 may be higher than the height position of the upper end of the foundation girder 14. That is, the foundation column 13 may protrude upward from the foundation girder 14.

[0085] The configurations of the above-described embodiments and each modification can be partially or entirely combined as long as there is no particular contradiction. The embodiments of the present disclosure are not limited to the above-described embodiments only, and all modifications, application examples, and equivalents included in the idea of the present disclosure defined by the claims are included in the present disclosure. Therefore, the present disclosure should not be interpreted restrictively, and can also be applied to any other technology belonging to the scope of the idea of the present disclosure.

Description of Reference Numerals

[0086] S Brace Attachment Structure 4 Steel Column 7 Lower End Portion 8 Brace 10 Gusset Plate 17 Base Plate 18 Gap 25 Continuous Diaphragm 27, 28 Split Pieces 29 Right side 30 Left side 32 Upper end face 33 Mounting part

Claims

1. A steel column with a column base formed in a tubular shape, a base plate attached to the lower surface of the steel column, a gusset plate attached to the column base of the steel column and the base plate, and a brace attached to the gusset plate, characterized in that a gap through which the gusset plate is inserted is provided in the column base of the steel column, and the gusset plate inserted into the gap is welded to the base plate inside the column base of the steel column. A brace mounting structure characterized by the above.

2. The gaps are provided on two opposing surfaces of the column base of the steel column, the gusset plate is inserted into the two gaps and penetrates the column base of the steel column. The brace mounting structure according to Claim 1.

3. A mounting portion of the brace is provided at one end of the gusset plate protruding from the column base of the steel column. The brace mounting structure according to Claim 1.

4. Mounting portions of the brace are provided at both ends of the gusset plate protruding from the column base of the steel column. The brace mounting structure according to Claim 1.

5. The column base of the steel column is composed of two split pieces split in a longitudinally split state, and the gap is provided between the two split pieces. The brace mounting structure according to Claim 1.

6. The two split pieces are formed by splitting a steel pipe into two. The brace mounting structure according to Claim 5.

7. A through diaphragm is welded to the upper end surfaces of the two split pieces and the upper end surface of the gusset plate. The brace mounting structure according to Claim 5.

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