Opening reinforcement method, and opening reinforcement member

Abstract

To provide an opening reinforcement method capable of improving the workability while strengthening the shear strength, bending strength and axial strength of a steel beam with an opening, and an opening reinforcement member.SOLUTION: An opening reinforcement member 20 is fixed by welding around an open hole 15 formed in a web 12 of a steel beam 10 to reinforce the area around an open hole 15. The opening reinforcement member 20 includes: a square frame 21 having a square frame shape that has four sides 25 arranged on the periphery of the open hole 15; and a plurality of plate portions 30 in which the ends are fixed to the inside of the adjacent side 25 at each corner of the square frame 21 connecting adjacent side portions 25.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to an opening reinforcement method and an opening reinforcement member for reinforcing a through hole formed in a web of a steel beam. [Background technology]

[0002] In steel beams such as H-shaped steel beams, through-holes are sometimes formed in the web portion to allow piping and wiring to pass through. In this case, a reinforcing member is provided to prevent a decrease in the beam's shear strength (see, for example, Patent Documents 1 and 2). In the beam through-hole reinforcing method described in Patent Document 1, the inclined surface of a ring-shaped reinforcing member is brought into contact with the inner surface of the through-hole in the beam material, and the inclined surface of the ring-shaped reinforcing member, which is temporarily fixed to the web portion of the beam material, is welded to the inner peripheral surface of the through-hole. In addition, the opening reinforcing member described in Patent Document 2 includes a cylindrical portion fixed to the periphery of the circular through-hole, and a square frame portion having multiple sides that contact the outer periphery of the cylindrical portion and that is integrated with the cylindrical portion via welding. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-174311 [Patent Document 2] Japanese Patent Publication No. 2022-115628 Summary of the Invention [Problem to be solved by the invention]

[0004] The beam through-hole reinforcing method of Patent Document 1 mentioned above can improve the shear strength of the steel beam, but it is difficult to sufficiently reinforce the bending strength and axial strength of the steel beam. Also, the opening reinforcing member of Patent Document 2 can reinforce the bending strength and axial strength of the steel beam, but the efficiency of the welding work is poor because the cylindrical part and the square frame part are welded together. [Means for solving the problem]

[0005] An opening reinforcement method that solves the above problem is a method of reinforcing an opening by joining around a through hole formed in the web of a steel beam to reinforce the area around the through hole, and the opening reinforcement member includes a rectangular frame portion having four sides that are arranged around the periphery of the through hole, and plate-shaped plate portions whose ends are fixed to the inside of the adjacent sides at each corner of the frame portion, connecting the adjacent sides, and is fixed around the through hole by welding.

[0006] In addition, an opening reinforcement member that solves the above problem is an opening reinforcement member that is joined to the periphery of a through hole formed in the web of a steel beam and reinforces the periphery of the through hole, and is equipped with a square frame portion having four sides that are arranged on the periphery of the through hole, and plate-shaped portions whose ends are fixed to the inside of the adjacent sides at each corner of the frame portion and connect the adjacent sides. [Effects of the Invention]

[0007] According to the present invention, it is possible to reinforce the shear strength, bending strength and axial strength of a steel beam having an opening, and also improve workability. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a perspective view of a steel beam having an opening reinforced by an opening reinforcing member according to an embodiment of the present invention. [Figure 2] FIG. 1 is a front view of a steel beam having an opening reinforced by an opening reinforcing member according to an embodiment. [Figure 3] FIG. 3 is a cross-sectional view taken along line 3-3 in FIG. 2. [Figure 4] FIG. 2 is a perspective view illustrating a configuration of an opening reinforcing member according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] An embodiment of an opening reinforcement method and an opening reinforcement member will be described below with reference to Figures 1 to 4. Figures 1 to 3 are a perspective view, a front view, and a side cross-sectional view of a steel beam provided with an opening reinforcement member, and Figure 4 is a perspective view of the opening reinforcement member.

[0010] As shown in Fig. 1, the steel beam 10 is made of an H-shaped steel having upper and lower flanges 11 and a web 12 connecting them. The width of the flanges 11 of the steel beam 10 is 300 mm, and the height of the web 12 is 700 mm, with the thickness of the web 12 being 13 mm. A circular through-hole 15 is formed in the web 12 to allow piping and wiring to pass through. The through-hole 15 is, for example, 350 mm in diameter.

[0011] As shown in FIG. 3, an opening reinforcing member 20 is provided on one surface of the web 12 so as to surround the through-hole 15. As shown in FIG. 2, in this embodiment, the opening reinforcing member 20 is positioned so that the extension direction of a pair of opposing side portions 25 of the rectangular frame portion 21 (described later) of the opening reinforcing member 20 is parallel to the extension direction of the flange portion 11.

[0012] 4, the opening reinforcement member 20 includes a rectangular frame portion 21 and four plate portions 30. The rectangular frame portion 21 is made of, for example, a rectangular steel pipe having vertical and horizontal lengths of 450 mm and a thickness of 60 mm, and has a substantially square shape with arc-shaped corners and four side portions 25.

[0013] The plate portion 30 has a rectangular plate shape in plan view, with a width of 60 mm and a thickness of 25 mm. Both ends of each plate portion 30 are welded to the inside of adjacent side portions 25 of the rectangular frame portion 21 at welds W1 so that each plate portion 30 faces each corner of the rectangular frame portion 21. In this case, each plate portion 30 is arranged so as to form a predetermined angle (preferably 45 degrees) with respect to the extension direction of each side portion 25. Furthermore, each plate portion 30 has a length that is approximately the same as the distance between the welds W1 on each side portion 25. As a result, as shown in FIG. 2, a substantially octagonal shape is formed by each plate portion 30 and the portion of each side portion 25 extending from welded portion W1 to welded portion W1.

[0014] The opening reinforcing member 20 is then disposed around the through hole 15 and welded. Specifically, a welded portion W5 on the outer periphery of the rectangular frame portion 21 of the opening reinforcing member 20 and a welded portion W6 on the outside of the plate portion 30 are welded so as to be positioned on the periphery of the through hole 15. In this case, it is desirable that the shortest distance L1 from the through hole 15 to the side portion 25 is the same as the shortest distance L2 from the through hole 15 to each plate portion 30. In this embodiment, the shortest distances L1 and L2 are, for example, 25 mm.

[0015] (action) The opening reinforcement member 20 of this embodiment has a rectangular frame portion 21 having a substantially square shape with four sides 25, and plate portions 30 disposed inside the rectangular frame portion 21 at 45-degree angles relative to each of the sides 25. This forms a substantially octagonal shape as a whole, thereby providing shear reinforcement around the through hole 15.

[0016] According to this embodiment, the following effects can be obtained. (1) The opening reinforcement member 20 of this embodiment has a rectangular frame portion 21 having a substantially square shape with four sides 25, and plate portions 30 arranged inside the rectangular frame portion 21 at a 45-degree angle relative to each of the sides 25. This allows the overall structure to form a substantially octagonal shape, which provides a shear reinforcement effect equal to or greater than that of a circular ring.

[0017] (2) The opening reinforcement member 20 of this embodiment can be made by simply cutting a square steel pipe into rings of a predetermined thickness to form the square frame portion 21 and welding both ends of the plate-shaped plate portion 30 to it, thereby improving workability.

[0018] (3) In this embodiment, the opening reinforcement member 20 is fixed to one side of the web 12 of the steel beam 10, so that the opening reinforcement member 20 can be easily fixed. (4) In this embodiment, the rectangular frame portion 21 of the opening reinforcing member 20 has a rounded rectangular shape, which makes it possible to suppress stress concentration at the corners of the rectangular frame portion 21.

[0019] This embodiment can be modified as follows: This embodiment and the following modifications can be combined and implemented within the scope of technical compatibility. In the above embodiment, the opening reinforcing member 20 is arranged so that the extension direction of the side portions 25 of the rectangular frame portion 21 is parallel to the extension direction of the flange portions 11. However, the arrangement of the opening reinforcing member 20 is not limited to this, and the opening reinforcing member 20 may be arranged so that the extension direction of the side portions 25 of the rectangular frame portion 21 forms an angle of 45 degrees with the extension direction of the flange portions 11.

[0020] In the above embodiment, the plate portion 30 is welded to the inside of the rectangular frame portion 21. The plate portion 30 is not limited to a plate shape, and may be, for example, an arc shape with its center point on the side of the through-hole 15. In this case, it is preferable that the angle formed by connecting both ends of the plate portion welded to the rectangular frame portion 21 forms an angle of 45 degrees with respect to the rectangular frame portion 21.

[0021] In the above embodiment, it is desirable that the shortest distance L1 from the through hole 15 to the side portion 25 and the shortest distance L2 from the through hole 15 to each plate portion 30 are the same. Alternatively, the shortest distance L2 from the through hole 15 to the plate portion 30 may be shorter or longer than the shortest distance L1 from the through hole 15 to the side portion 25. For example, when a commercially available square steel pipe is used as the square frame portion 21, the shortest distance L1 from the through hole to the square frame portion 21 may be longer than the optimal value. In this case, the plate portion is arranged at a 45-degree angle so that the shortest distance L2 from the through hole to the plate portion is the optimal value shorter than the shortest distance L1.

[0022] In the above embodiment, welding was performed by providing welds W5 and W6 on the outer peripheral edge of the rectangular frame portion 21 of the opening reinforcement member 20 and on the outside of the plate portion 30 in the web 12 of the steel beam 10. The welding positions and welding method for fixing the opening reinforcement member 20 to the web 12 are not limited to this. For example, welding may be performed using multiple spaced welds on the outer peripheral edge of the rectangular frame portion 21, or welding may be performed on the inside of the plate portion 30 and on the inside between welds W1 on the side portions 25.

[0023] In the above embodiment, the opening reinforcement member 20 is provided on one side of the steel beam 10. The opening reinforcement member 20 may be provided on both sides of the steel beam 10. In this case, one of the opening reinforcement members 20 may be arranged so that the opposing sides of the rectangular frame portion 21 are rotated 45 degrees relative to the extension direction of the flange portion 11, instead of being arranged parallel to the extension direction of the flange portion 11. In the above embodiment, the rectangular frame portion 21 and the plate portion 30 of the opening reinforcing member 20 have the same thickness. The rectangular frame portion and the plate portion do not have to have the same thickness.

[0024] Next, the technical ideas that can be understood from the above-described embodiment and other examples will be described below. (a) The opening reinforcing method according to claim 1, wherein the plate portion is provided at an angle of approximately 45 degrees to the side of the frame portion. (b) The opening reinforcing method according to claim 1 or (a), characterized in that the shortest distance from the through hole to the plate portion is the same as the shortest distance from the through hole to the side portion. (c) The opening reinforcement method described in (a) or (b) in claim 1, characterized in that the length of the four plate portions and the length between adjacent plate portions welded on the sides are approximately the same, and the plate portions and the center of the frame portion have an approximately octagonal shape. (d) The opening reinforcement method described in (a), (b) or (c) of claim 1, characterized in that the opening reinforcement member 20 is fixed to the web by welding the outer periphery of the frame portion to the outside of the plate portion. [Explanation of symbols]

[0025] L1, L2...shortest distance, W1, W5, W6...weld section, 10...steel beam, 11...flange section, 12...web, 15...through hole, 20...opening reinforcement member, 21...rectangular frame section, 25...side section, 30...plate section.

Claims

1. A method for reinforcing an opening by joining a through hole formed in a web of a steel beam to reinforce the periphery of the through hole, An opening reinforcement method characterized by fixing an opening reinforcement member comprising: a rectangular frame portion having four sides arranged on the periphery of the through hole; and a plate-shaped plate portion having ends fixed to the inside of adjacent sides at each corner of the frame portion, connecting the adjacent sides, the ends of which are fixed to the inside of the adjacent sides at each corner of the frame portion, around the through hole by welding.

2. An opening reinforcement member that is joined to the periphery of a through hole formed in a web of a steel beam and reinforces the periphery of the through hole, A rectangular frame having four sides and disposed on the periphery of the through hole; An opening reinforcing member characterized by comprising: a plate-shaped plate portion having an end portion fixed to the inside of an adjacent side portion at each corner of the frame portion, connecting the adjacent side portions.

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