Earthquake-resistant reinforcement structure

Abstract

To provide a seismic retrofitting structure that enables brace installation without removing obstacles that interfere with brace installation work.SOLUTION: A seismic retrofitting structure 10 includes a bracket 30 joined to a pedestal portion 20 of an indoor side chord member 14B of a truss pillar 14 and a pedestal portion 20 of an outdoor side chord member 14A of the truss pillar 14, and a vertical brace 32 with a lower end attached to the bracket 30 and an upper end attached to the top of the outdoor side chord member 14A of another truss pillar 14 located next to the truss pillar 14.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an earthquake-resistant reinforcement structure for use in buildings. [Background technology]

[0002] For example, in a building with a steel-framed column-beam structure, braces may be attached to the column-beam structure in order to increase earthquake resistance (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-172139 A [Patent Document 2] JP 2019-138089 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, when retrofitting braces into the column-beam structure of an existing building for seismic retrofitting, the following problems can arise. For example, if a spandrel is adjacent to the outer chord of a truss column to which a brace is to be retrofitted, the spandrel gets in the way, making it difficult to attach a brace to the column base of the outer chord. For this reason, in the past, obstacles that got in the way of installing braces on spandrel walls, etc., had to be removed before the installation work could be carried out, making the seismic retrofitting work extremely time-consuming.

[0005] In consideration of the above, an object of the present invention is to provide an earthquake-resistant reinforcement structure that enables braces to be installed without removing obstacles that hinder the brace installation work. [Means for solving the problem]

[0006] In the first aspectThe described earthquake-resistant reinforcement structure comprises a connecting member connected to the base portion of the indoor chord of a truss column and the base portion of the outdoor chord of the truss column, and a vertical brace whose lower end is attached to the connecting member and whose upper end is attached to the top of the outdoor chord of another truss column arranged next to the truss column.

[0007] In the first aspect In the described earthquake-resistant reinforcement structure, the lower end of the vertical brace is attached not to the outdoor chord of the truss column, but to a joint member that is joined to the column base of the indoor chord of the truss column and the column base of the outdoor chord. Therefore, the vertical brace can be retrofitted to the truss column of an existing building without being hindered by obstacles such as spandrel walls.

[0008] In the second aspect The invention described is First aspect In the earthquake-resistant reinforcement structure described in the above, the connecting member comprises a pair of wing plates spanned and joined to both side surfaces of the outdoor chord and the indoor chord, and filling material filled between the pair of wing plates, and a bracket for attaching the lower end of a vertical brace is joined to the connecting member.

[0009] In the second aspect In the described earthquake-resistant reinforcement structure, the joint member is configured by connecting the outdoor chord member and the indoor chord member to each other by bridging wing plates across both sides of the chord member, and filling material is filled between the pair of wing plates. This allows the load acting on the joint member to be distributed between the outdoor chord member and the indoor chord member.

[0010] Furthermore, a bracket is joined to the joining member, which facilitates the installation of the lower end of the vertical brace.

[0011] In the third aspect The invention described is a first or In the second aspect In the earthquake-resistant reinforcement structure described above, a post-installed anchor is provided to fix the base plate of the truss column to a concrete foundation.

[0012] In the third aspectIn the described earthquake-resistant reinforcement structure, the post-installed anchors that fix the base plate of the truss column to the concrete foundation are provided, so the pull-out resistance of the truss column is greater than that of a structure without the post-installed anchors. This makes it possible to prevent the base plate from lifting off the concrete foundation even if a large force is transmitted from the vertical brace to the base plate during an earthquake. Effect of the Invention

[0013] As described above, according to the earthquake-resistant reinforcement structure of the present invention, it is possible to install the braces without removing obstacles that would hinder the brace installation work. [Brief description of the drawings]

[0014] [Figure 1] 1 is a front view of an earthquake-resistant reinforcement structure according to one embodiment of the present invention, seen from the indoor side. [Diagram 2] 1 is a cross-sectional view perpendicular to an outer wall surface showing an earthquake-resistant reinforcement structure according to one embodiment of the present invention. [Diagram 3] 1 is a perspective view showing the vicinity of the base of a truss column of an earthquake-resistant reinforcement structure according to one embodiment of the present invention, viewed from the indoor side. FIG. [Figure 4] FIG. 2 is a side view showing the mounting portion of a vertical brace in a truss column of an earthquake-resistant reinforcement structure according to one embodiment of the present invention, viewed from a direction perpendicular to the outer wall surface. [Diagram 5] FIG. 2 is a front view seen from the indoor side showing the upper end mounting portion of a vertical brace in a truss column of an earthquake-resistant reinforcement structure according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] An earthquake-resistant reinforcement structure 10 according to one embodiment of the present invention will be described with reference to Figs. 1 to 5. 1 and 2, a building 12 to which the earthquake-resistant reinforcement structure 10 of this embodiment is applied has a plurality of truss columns 14 provided at intervals along an exterior wall 38 described below. The truss columns 14 are erected on a floor 16 serving as a concrete foundation.

[0016] The truss column 14 is of a typical construction made of steel material including an outdoor chord 14A arranged on the outdoor side (the side opposite the direction of arrow Y in Figure 2), an indoor chord 14B arranged on the indoor side (the side in the direction of arrow Y in Figure 2), and multiple diagonal members 14C connecting the outdoor chord 14A and the indoor chord 14B.

[0017] 2 and 3, a waist wall 18 made of concrete blocks or the like is disposed on the outdoor side of the outdoor chord 14A of the truss column 14. The outdoor chord 14A of the truss column 14 is disposed with its lower portion facing the waist wall 18. In this embodiment, the outdoor chord 14A is in close contact with the waist wall 18, but there may be a slight gap between the outdoor chord 14A and the waist wall 18.

[0018] A joint member 19 is provided on a column base 20, which is a lower portion of the truss column 14. The joint member 19 includes a pair of wing plates 22, which will be described below, and concrete 24, which is an example of a filler material.

[0019] The lower portion of the indoor chord 14B and the lower portion of the outdoor chord 14A are sandwiched and connected by a pair of wing plates 22. The wing plates 22 are made of steel plates, and are joined by welding or the like to the side surfaces of the indoor chord 14B and the outdoor chord 14A.

[0020] In the lower part of the truss column 14, the space above the floor 16 and surrounded by the pair of wing plates 22, the indoor chord 14B, and the outdoor chord 14A is filled with concrete 24 as an example of a filler material to reinforce the space. Note that the concrete 24 may be replaced with other types of filler materials such as grout material as long as the lower part of the truss column 14 can be reinforced.

[0021] The lower ends of the wing plates 22 are joined by welding or the like to a rectangular base plate 23 made of a steel plate that is arranged on the floor 16 .

[0022] Three anchor bolts 26 are provided for one base plate 23 on the floor 16. The upper end portion of each anchor bolt 26 passes through a hole (not shown) formed in the base plate 23 and protrudes above the base plate 23.

[0023] A nut 28 for fixing the base plate 23 to the floor 16 is screwed onto the male threaded portion of the anchor bolt 26 protruding above the base plate 23 .

[0024] The two anchor bolts 26 arranged on both longitudinal sides of the base plate 23 are existing ones that were installed when the building 12 was constructed, and the central anchor bolt 26 is an example of a post-installed anchor of the present invention, which was installed later to reinforce the existing building 12 against earthquakes.

[0025] A bracket 30 is attached to the pair of wing plates 22. The bracket 30 is U-shaped with an open bottom, is disposed horizontally sandwiching the pair of wing plates 22, and is joined to the side surfaces of the wing plates 22 and the upper surface of the base plate 23 by welding or the like.

[0026] The lower end of a brace 32 serving as a vertical brace is connected to the bracket 30. A shuttlecock 34 made of a steel plate is joined to the lower end of the bracket 30 by welding or the like. The shuttlecock 34 is disposed along the bracket 30, and the lower end of the brace 32 is connected to the bracket 30 by fixing the bracket 30 and the shuttlecock 34 together using bolts 36 and nuts 44 (not shown in FIG. 1).

[0027] The shuttlecock 34 may be joined to the bracket 30 by welding. Also, the lower end of the brace 32 may be joined to the bracket 30 by welding.

[0028] 2 and 3, an exterior wall 38 is provided on the outdoor side of the waist wall 18. The exterior wall 38 is attached to the side of the outdoor-side chord 14A via support brackets 40. Above the upper end of the waist wall 18, a gap S1 is provided between the exterior wall 38 and the outdoor-side chord 14A. Incidentally, in this embodiment, the thickness of the gap S1 above the waist wall 18 is equal to the thickness of the waist wall 18.

[0029] 1, 4, and 5, the upper end of the brace 32 is connected to the upper side surface (the side surface in the direction of arrow X and the side surface in the direction opposite to the direction of arrow X) of the outdoor chord member 14A of another adjacent truss column 14. A shuttlecock 34 similar to that of the lower end portion is joined by welding or the like to the upper end portion of the brace 32, and this shuttlecock 34 is fixed by bolts 36 and nuts 44 to a fixing plate 42 joined by welding or the like to the upper side surface of the outdoor chord member 14A (for example, the column capital).

[0030] In addition, a roof beam 48 is supported on the upper part of the truss column 14.

[0031] (earthquake-resistance reinforcement) Next, the process for seismically reinforcing an existing building that does not have braces will be described below. An existing building without a brace means a building without the bracket 30, the brace 32, the fixing plate 42, and the anchor bolt 26 at the center of the base plate 23 shown in Fig. 1 etc. An illustration of the existing building is omitted.

[0032] To perform seismic reinforcement for an existing building, first, holes for inserting the anchor bolts 26 to be added are formed in the center of the wing plates 22 of the base plate 23 and in the floor 16 below. The anchor bolts 26 are inserted into these holes and fixed to the floor 16 using grout or the like. After the anchor bolts 26 are fixed, the nuts 28 are screwed onto the male threads of the anchor bolts 26 protruding from the base plate 23 and tightened (see FIG. 3). In the building 12 of this embodiment, the anchor bolts 26 are added, so that the joint strength between the base plate 23 of the truss column 14 and the floor 16 can be increased compared to an existing building.

[0033] Next, the brackets 30 are joined to the wing plates 22 and base plate 23 of each truss column 14 by welding or the like (see FIG. 3). Also, a fixing plate 42 is joined to the upper side surface of the outdoor-side chord 14A of each truss column 14 by welding or the like (see FIGS. 4 and 5).

[0034] 1, the shuttlecock 34 provided on one end of the brace 32 is fixed to the bracket 30 of one of the adjacent truss columns 14 using the bolt 36 and the nut 44. Also, the shuttlecock 34 provided on the other end of the brace 32 is fixed to the fixing plate 42 of the other adjacent truss column 14 using the bolt 36 and the nut 44.

[0035] Furthermore, the weight of the roof of the building 12 and the force from the roof act on the truss columns 14, but since the force from the roof tends to be transmitted to the outdoor chord 14A rather than the indoor chord 14B, it is preferable to attach the brace 32 that provides earthquake reinforcement to the outdoor chord 14A.

[0036] Therefore, in this embodiment, the upper end side of the brace 32 is connected to the outdoor-side chord 14A. There is sufficient space on the indoor side at the top of the outdoor-side chord 14A, and a gap S1 is provided between the outdoor-side chord 14A and the exterior wall 38 on the outdoor side. This makes it possible to weld the fixing plate 42 to the upper side surface of the outdoor-side chord 14A of an existing building and to attach the brace 32 to the fixing plate 42 without any problems.

[0037] As shown in FIG. 2, the upper end of the brace 32 is connected to the outdoor chord 14A, and the lower end is connected to a bracket 30 located away from the outdoor chord 14A toward the indoor side. Therefore, when viewed from a direction perpendicular to the exterior wall 38 (when viewed along the direction of arrow X), the brace 32 is slightly inclined relative to the vertical direction.

[0038] However, if one were to attach the brace 32 to the lower side surface of the outdoor-side chord 14A in the same way as the upper portion of the outdoor-side chord 14A, the waist wall 18, which is in close contact with the outdoor-side chord 14A, would get in the way, making it difficult to weld the bracket 30 and attach the brace 32. In other words, the waist wall 18 is an obstacle that gets in the way of the seismic reinforcement work.

[0039] On the other hand, according to the earthquake-resistant reinforcement structure 10 of this embodiment, as shown in Figures 2 and 3, the bracket 30 for attaching the brace 32 is provided at a position away from the outdoor-side chord 14A toward the indoor side, so that a working space S2 is secured between the bracket 30 and the waist wall 18. Therefore, the bracket 30 can be welded to the wing plate 22 and the base plate 23 without the waist wall 18 adjacent to the outdoor-side chord 14A getting in the way. Also, the brace 32 can be connected to the bracket 30 without the waist wall 18 getting in the way.

[0040] In this way, according to the earthquake-resistant reinforcement structure 10 of this embodiment, there is no need to remove the spandrel wall 18, which is an obstacle that gets in the way of the brace installation work when performing earthquake-resistant reinforcement, and the braces 32 can be easily retrofitted even in an existing building 12, making earthquake-resistant reinforcement easy.

[0041] In addition, according to the earthquake-resistant reinforcement structure 10 of this embodiment, wing plates 22 are spanned and joined to both side surfaces of the outdoor-side chord 14A and the indoor-side chord 14B, and concrete 24 is filled between the pair of wing plates 22, so that the load acting on the bracket 30 can be distributed between the outdoor-side chord 14A and the indoor-side chord 14B.

[0042] In addition, since the bracket 30 for attaching the shuttlecock 34 with the bolt 36 and nut 44 is joined to the wing plate 22, the attachment work for the lower end of the brace 32 can be carried out smoothly.

[0043] Furthermore, according to the earthquake-resistant reinforcement structure 10 of this embodiment, the anchor bolts 26 that fix the base plate 23 of the truss column 14 to the floor 16 serving as a concrete foundation are added later, so the pull-out resistance of the truss column 14 is greater than in the case where the anchor bolts 26 are not added later. This makes it possible to prevent the base plate 23 from lifting up from the floor 16 even if a large force is transmitted to the base plate 23 from the braces 32 during an earthquake.

[0044] [Other embodiments] Although one embodiment of the present invention has been described above, the present invention is not limited to the above, and it goes without saying that the present invention can be implemented in various modified forms without departing from the spirit and scope of the present invention.

[0045] The position at which the bracket 30 is joined to the wing plate 22 is not limited to the position shown in Fig. 3. The joining position of the bracket 30 can be changed as appropriate taking into consideration the mounting work of the bracket 30 and the mounting work of the brace 32, and may be on the indoor side (the direction of the arrow Y) from the position shown in Fig. 3.

[0046] Although the bracket 30 in the above embodiment is U-shaped with an opening at the bottom, the shape of the bracket 30 is not limited to the shape shown in FIG.

[0047] In the building 12 of the above embodiment, a waist wall 18 that gets in the way of earthquake reinforcement work was provided adjacent to the outdoor chord 14A, but something other than the waist wall 18 may be provided adjacent to the outdoor chord 14A and get in the way of earthquake reinforcement work. [Explanation of symbols]

[0048] 10 Earthquake-resistant reinforcement structure 12. Building 14 Truss column 14A Outdoor side chord 14B Indoor chord 16 Floor (concrete foundation) 19 Joint materials 20 Column base 22 Wing plate (jointing material) 23 Base plate 24 Concrete (joints, fillers) 26 Anchor bolt (post-installed anchor) 30 Bracket 32 Brace (Vertical Brace)

Claims

1. A joint member joined to a base portion of the indoor chord of the truss column and a base portion of the outdoor chord of the truss column; a vertical brace having a lower end attached to a bracket provided on the joint member and an upper end attached to an upper portion of an outdoor chord member of another truss column arranged next to the truss column; The brackets are integrally formed, and the lower end of the vertical brace attached to the upper part of the outdoor chord of another truss column arranged adjacent to one of the brackets and the lower end of the vertical brace attached to the upper part of the outdoor chord of another truss column arranged adjacent to the other bracket are respectively attached to the brackets. Earthquake-resistant reinforced structure.

2. The joint member includes a pair of wing plates that are spanned across and joined to both side surfaces of the outdoor chord member and the indoor chord member, and a filler material that is filled between the pair of wing plates, A bracket for attaching the lower end of the vertical brace is joined to the joining member. The earthquake-resistant reinforcement structure according to claim 1.

3. A post-installed anchor is provided to fix the base plate of the truss column to a concrete foundation. The earthquake-resistant reinforcement structure according to claim 1 or 2.

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