Method for forming a joining structure and joining structure

Abstract

Provided is a method for forming a joint structure or the like that can perform the joint of a steel frame beam with a simple detail. 【Solution means】The joint structure 10 joins the end of the secondary beam 2 on the side of the main beam 1. In the joint structure 10, the upper flange of the secondary beam 2 is arranged at the same height as the upper flange of the main beam 1, and the upper flanges of the secondary beams 2 on both sides of the main beam 1 are joined using the attachment plate 4 and the fastener 5, and the plate 11 provided on the main beam 1 and the web of the secondary beam 2 are joined using the fastener 3 arranged in the overlapping portion with the web of the plate 11. When forming the joint structure 10, the number of the fasteners 3 for bending load among the fasteners 3 arranged in the overlapping portion and the height of the bending load portion A where the fasteners 3 for bending load are arranged in the height range hitting the lower half of the web in the overlapping portion are determined so as to be able to bear a predetermined bending stress. A plate 11 having a bending load portion A is manufactured, and the joint structure 10 is formed using the plate 11.

Description

Technical Field

[0001] The present invention relates to a method for forming a joint structure of a steel beam and the like.

Background Art

[0002] In a steel-frame building, the joint at the end of a secondary beam may be a rigid joint that restricts the rotation of the end of the secondary beam. As a result, the maximum bending stress and deformation of the secondary beam are reduced, the cross-section (hereinafter sometimes simply referred to as the cross-section) perpendicular to the longitudinal direction of the secondary beam can be reduced, and the amount of steel can be reduced.

[0003] FIG. 6(a) shows an example of the joint structure at the end of a secondary beam 200. The secondary beam 200 is arranged in a direction perpendicular to the main beam 100 in a plane. The main beam 100 and the secondary beam 200 are steel beams made of H-shaped steel. The upper flanges (hereinafter referred to as the upper flanges) of the main beam 100 and the secondary beam 200 are at the same height, but the web of the main beam 100 is larger than that of the secondary beam 200, and the lower flange (hereinafter referred to as the lower flange) of the main beam 100 is at a lower position than the lower flange of the secondary beam 200.

[0004] In the example of FIG. 6(a), a bracket 110 for receiving the secondary beam 200 is welded to the main beam 100, and the end of the secondary beam 200 on the main beam 100 side (hereinafter simply referred to as the end of the secondary beam 200) is rigidly joined to the end of the bracket 110 on the secondary beam 200 side. An H-shaped steel having the same cross-section as the secondary beam 200 is used for the bracket 110, and the upper flanges and the lower flanges of the bracket 110 and the secondary beam 200 are joined using an attachment plate (splice plate) 310 and a fastener 320 with bolts and nuts. Thereby, the end of the secondary beam 200 is rigidly joined. The webs of the bracket 110 and the secondary beam 200 are joined using an attachment plate 330 and a fastener 340 with bolts and nuts, whereby it becomes possible to transmit shear stress between the bracket 110 and the secondary beam 200.

[0005] In the example of Fig. 6(b), the secondary beams 200 are provided on both sides of the main beam 100. At the end of each secondary beam 200, a CT-shaped steel 210 with a T-shaped cross-section is welded to the lower flange of each secondary beam 200. Thereby, the height of the lower flange of the main beam 100 and the flange of the CT-shaped steel 210 are made the same, and using an attachment plate 310 and a fastener 320 arranged so as to straddle the lower surface of the lower flange of the main beam 100, the flanges of the CT-shaped steels 210 of the secondary beams 200 on both sides of the main beam 100 are joined together. Also, using an attachment plate 310 and a fastener 320 arranged so as to straddle the upper surface of the upper flange of the main beam 100, the upper flanges of the secondary beams 200 on both sides of the main beam 100 are joined together in the same manner. Thereby, the ends of the secondary beams 200 are rigidly joined. Further, the plate (gusset plate) 120 provided on the main beam 100 and the web of the secondary beam 200 are joined using a fastener 340, whereby it becomes possible to transmit the shear force between the plate 120 and the secondary beam 200.

[0006] In the example of Fig. 6(c), the end of the secondary beam 200 is notched, and the height of the lower flange is lowered to match the lower flange of the main beam 100. Thereby, the height of the lower flanges of the main beam 100 and the secondary beam 200 are made the same, and using an attachment plate 310 and a fastener 320 arranged so as to straddle the lower surface of the lower flange of the main beam 100, the lower flanges of the secondary beams 200 on both sides of the main beam 100 are joined together. Also, similar to the example of Fig. 6(b), using an attachment plate 310 and a fastener 320 arranged so as to straddle the upper surface of the upper flange of the main beam 100, the upper flanges of the secondary beams 200 on both sides of the main beam 100 are joined together in the same manner. Thereby, the ends of the secondary beams 200 are rigidly joined.

[0007] Also, in Patent Document 1, it is described that the upper flanges of the secondary beams on both sides of the main beam are joined together using an attachment plate and a fastener in the same manner as above, and the lower flanges of the secondary beams on both sides of the main beam are joined together using an attachment plate and a fastener that penetrate the web of the main beam.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0009] Although the ends of the secondary beam 200 can be rigidly joined by these methods, since the heights of the lower flanges of the main beam 100 and the secondary beam 200 are different, particularly complex details are required regarding how to arrange the attachment plate 310 on the lower side of the secondary beam 200, which has entailed costs and labor for production.

[0010] The present invention has been made in view of the above problems, and an object thereof is to provide a method for forming a joint structure that can join steel beams with simple details.

Means for Solving the Problems

[0011] A first invention for solving the above problems is a joint structure for an end portion on the main steel beam side of a second steel beam arranged in a direction intersecting the first steel beam in a plane, wherein the upper flange of the second steel beam is arranged at the same height as the upper flange of the first steel beam, and the upper flange of the second steel beam is arranged on the opposite side of the second steel beam across the first steel beam from the upper flange of another second steel beam, or is joined to the upper flange of the first steel beam using an attachment plate and a fastener, and a plate provided on the first steel beam and the web of the second steel beam are joined using a fastener arranged at an overlapping portion of the web of the plate, and a method for forming the joint structure, wherein the number of bending load-bearing fasteners among the fasteners arranged at the overlapping portion and the height of a bending load-bearing portion where the bending load-bearing fasteners are arranged in a height range corresponding to the lower half of the web at the overlapping portion are determined so as to be able to bear a predetermined bending stress, and a plate having the bending load-bearing portion is manufactured, and the joint structure is formed using the plate. the aforesaid plate, and forming the joint structure using the plate. recording A method for forming a joint structure, characterized by comprising the steps of:

[0012] In the present invention, with the above configuration, while making the end of a steel frame beam (second steel frame beam) such as a lattice beam a rigid joint, the joint structure can be made into a simple structure without providing an attachment plate or fasteners on the lower side of the steel frame beam. Further, by omitting the lower attachment plate or the like, the design and aesthetic properties when looking up at the beam bottom from below can be improved.

[0013] For example, in the overlapping portion, the shape of the plate is determined such that the bending load portion projects toward the second steel frame beam side. Since the fasteners for bending load are arranged in the bending load portion within the limited height range as described above, by determining the shape of the plate such that the bending load portion projects toward the second steel frame beam side, it becomes easy to secure a space sufficient to arrange the required number of fasteners for bending load.

[0014] The number of the fasteners for bending load and the height of the bending load portion are determined such that a couple is formed between the bending load portion and the attachment plate when the bending stress is borne. The height of the bending load portion is determined such that the cross-sectional area in the height direction of the bending load portion is equal to the cross-sectional area in the width direction of the attachment plate. Thereby, a couple can be formed between the upper and lower joints of the second steel frame beam when the bending stress is borne.

[0015] The load of the first steel frame beam is fault desirably larger than that of the second steel frame beam. The joint structure formed by the forming method of the present invention is typically applied when the loads of steel frame beams such as a main beam and a lattice beam are different, and compared with the joint structure shown in FIGS. 6(a) to 6(c) above, the effect of simplification by omitting the lower attachment plate is significant.

[0016] The second invention is a joining structure of the end portion on the side of the first steel girder of the second steel girder arranged in a direction intersecting with the first steel girder in a plane, wherein the upper flange of the second steel girder is arranged at the same height as the upper flange of the first steel girder, the upper flange of the second steel girder is joined to the upper flange of another second steel girder arranged on the opposite side of the second steel girder across the first steel girder, or to the upper flange of the first steel girder using an attachment plate and fasteners, the plate provided on the first steel girder and the web of the second steel girder are joined using fasteners arranged at the overlapping portion of the plate and the web, the fasteners arranged at the overlapping portion include fasteners for bending load, the fasteners for bending load are arranged at the bending load portion located in the height range hitting the lower half of the web at the overlapping portion, and at the overlapping portion, the bending load portion projects toward the second steel girder side. The joining structure of the second invention is among the joining structures formed by the forming method of the first invention, those in which the bending load portion projects toward the second steel girder side.

Effects of the Invention

[0017] According to the present invention, it is possible to provide a forming method of a joining structure capable of joining steel girders with a simple detail.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0019] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

[0020] (1. Joint structure 10) FIG. 1 is a diagram showing a joint structure 10 formed by the forming method according to an embodiment of the present invention. The joint structure 10 is for joining the end of the secondary beam 2 on the side of the main beam 1 (hereinafter simply referred to as the end of the secondary beam 2), and in particular, it performs rigid joint of the end of the secondary beam 2 with a simple detail. The main beam 1 and the secondary beam 2 are steel frame beams using H-shaped steel. In this case, the rigid joint of the end of the secondary beam 2 refers to a joining method that can restrain at least the bending of the end of the secondary beam 2 by joining the upper and lower parts of the secondary beam 2. By performing rigid joint of the end of the secondary beam 2, the bending stress can be borne at the joint and transmitted.

[0021] The secondary beam 2 (second steel frame beam) is a steel frame beam arranged on the side of the main beam 1 (first steel frame beam) in the lateral direction in the beam width direction of the main beam 1 and intersecting the main beam 1 in a plane. The secondary beam 2 of the present embodiment is arranged on both sides of the main beam 1 so as to be orthogonal to the main beam 1 in a plane. The beam width direction is a direction orthogonal to the longitudinal direction of the steel frame beams (main beam 1 and secondary beam 2) in a plane, and the beam width direction of the main beam 1 corresponds to the left - right direction in FIG. 1. The upper flanges (hereinafter referred to as upper flanges) of the main beam 1 and the secondary beam 2 are at the same height, but the height of the main beam 1 is larger than that of the secondary beam 2, and the lower flange of the main beam 1 is at a lower position than the lower flange (hereinafter referred to as lower flange) of the secondary beam 2.

[0022] Also, the upper flange of one secondary beam 2 (second steel frame beam) and the upper flange of the other secondary beam 2 (another second steel frame beam) located on the opposite side of the secondary beam 2 across the main beam 1 are joined using a rectangular gusset plate (splice plate) 4 and a fastener 5 composed of bolts and nuts. That is, the gusset plate 4 is arranged so as to straddle the upper surface of the upper flange of the main beam 1, and the part of the gusset plate 4 on the side of one secondary beam 2 and the upper flange of the secondary beam 2 are fastened using the fastener 5, and the part of the gusset plate 4 on the side of the other secondary beam 2 and the upper flange of the secondary beam 2 are fastened using the fastener 5. High - strength bolts are used as the bolts of the fastener 5. Note that high - strength bolts include ultra - high - strength bolts.

[0023] In the joining structure 10 of the present embodiment, a plate (gusset plate) 11 for joining with the secondary beam 2 is provided on the main beam 1. The plate 11 is a steel plate provided between the upper and lower flanges on both sides of the web of the main beam 1, and is fixed by welding to the upper and lower flanges and the web of the main beam 1.

[0024] The plate 11 protrudes from the main beam 1 toward the secondary beam 2, and the overlapping portion with the web of the secondary beam 2 is joined to the web of the secondary beam 2 using a plurality of fasteners 3. The fastener 3 includes a bolt 31 and a nut. Holes (not shown) are formed at corresponding positions of the plate 11 and the web of the secondary beam 2. By passing the bolt 31 from the side of the plate 11 or the web of the secondary beam 2 and tightening the nut on the tip of the bolt 31 protruding from the opposite side, the plate 11 and the web of the secondary beam 2 are fastened. A high-strength bolt is used as the bolt 31.

[0025] A part of the fastener 3 is provided to bear the bending stress, and is arranged in the height range hitting the lower half of the web of the secondary beam 2 in the overlapping portion of the plate 11. The range A in FIG. 1 shows the bending load portion where the fastener 3 is arranged, and has a predetermined height H from the lower end of the overlapping portion.

[0026] The remaining fasteners 3 bear the shear stress and are for transmitting the shear stress between the secondary beam 2 and the plate 11. The portion other than the bending load portion A of the overlapping portion of the plate 11 becomes a shear load portion that bears the shear stress. Since the fastener 3 for bending load and the bending load portion A are arranged in the height range hitting the lower half of the web of the secondary beam 2, the fastener 3 for shear load and the shear load portion are mainly arranged in the height range hitting the upper half of the web of the secondary beam 2 in the overlapping portion of the plate 11.

[0027] The joint structure 10 can be said to replace the attachment plate 310 and the fastener 320 used for joining the lower flange of the joist 200 in FIGS. 6(a) to 6(c) with the bending load portion A of the plate 11 and the fastener 3 for bending load. By restraining the bending of the end portion of the joist 2 and bearing the bending stress at the joint portion between the upper and lower portions of the joist 2, a rigid joint is realized. In the present embodiment, as will be described later, based on a predetermined rule, the number of fasteners 3 (bolts 31) for bending load, the size of the bending load portion A of the plate 11, and the like are determined.

[0028] (2. Method for forming the joint structure 10) FIG. 2 is a flowchart showing a method for forming the joint structure 10. In the present embodiment, first, based on the width of the flange of the joist 2 to be joined, the width of the attachment plate 4 disposed above the girder 1 and the joist 2 is determined (S1). The width of the attachment plate 4 is, for example, made equal to the width of the upper flange of the joist 2. The width of the attachment plate 4 and the width of the upper flange of the joist 2 correspond to the length in the beam width direction of the attachment plate 4 and the upper flange of the joist 2 (corresponding to the direction normal to the plane of FIG. 1).

[0029] Next, the height H and thickness of the bending load portion A of the plate 11 and the number of fasteners 3 (bolts 31) of the bending load portion A are determined so as to be able to bear a predetermined bending stress (S2, S3).

[0030] In S2 and S3, for example, at the time of bearing the bending stress, the height H and thickness of the bending load portion A and the number of fasteners 3 of the bending load portion A are determined so that a couple T is established between the attachment plate 4 (joint portion at the upper part of the joist 2) and the bending load portion A (joint portion at the lower part of the joist 2). The couple T is a tensile force and a compressive force of the same magnitude along the longitudinal direction of the joist 2.

[0031] More specifically, as the simplest method, the height H and thickness of the bending load portion A are determined such that the cross-sectional area in the height direction of the bending load portion A is equal to the cross-sectional area in the width direction of the attachment plate 4, and the number of fasteners 3 of the bending load portion A is determined to be the same as the number of fasteners 5 on the side of the joist 2 to be joined. However, when the bolt diameters are different between the fastener 3 and the fastener 5, the numbers of the fastener 3 and the fastener 5 do not necessarily become the same.

[0032] Next, the length L of the bending load portion A in the overlapping portion of the plate 11 (the length along the longitudinal direction of the crossbeam 2) is determined so that the fastening members 3 for bending load can be arranged at a predetermined pitch in the longitudinal direction of the crossbeam 2 for the number of fastening members 3 determined by S3 (S4). The length L is determined according to the above pitch, the number of fastening members 3, and the number of upper and lower stages for arranging the fastening members 3. In principle, the fastening members 3 are arranged horizontally. However, if only one row is arranged, the required length L becomes large and the plate 11 becomes too large. In this case, as shown in FIG. 1, the fastening members 3 may be arranged in a plurality of upper and lower rows (two rows in the example of FIG. 1). Thereby, the required length L can be reduced.

[0033] After that, the overall shape of the plate 11 is determined (S5). Since the overlapping portion of the plate 11 also requires fastening members 3 for shear load and shear load portions, the overall shape of the plate 11 is determined so that the required number of fastening members 3 for shear load can be arranged in the shear load portion of the plate 11 and the shear load portion can bear the required shear stress. In the present embodiment, since it is necessary to arrange the required number of fastening members 3 for bending load in the bending load portion A within a limited height range, the length L tends to become large. As a result, the overlapping portion of the plate 11 has a trapezoidal shape in which the bending load portion A protrudes toward the crossbeam 2 side.

[0034] After determining the shape of the plate 11 in this way, the plate 11 is manufactured, and the joint structure 10 at the end of the crossbeam 2 is formed using the plate 11 or the like as shown in FIG. 1 (S6).

[0035] As described above, in the present embodiment, while the end of the crossbeam 2 is rigidly joined, the joint structure 10 can be made into a simple configuration in which no attachment plate or fastening member is provided below the main beam 1 or the crossbeam 2. Further, by omitting the attachment plate or the like on the lower side, the design and aesthetic properties when looking up at the beam bottom from below can be improved.

[0036] In addition, since the fastener 3 for bending load is arranged in the bending load portion A within the limited height range as described above, by determining the shape of the plate 11 so that the bending load portion A projects toward the side of the secondary beam 2, it becomes easier to secure a space for arranging the necessary number of fasteners 3 for bending load.

[0037] In this embodiment, the number of fasteners 3 for bending load and the height H of the bending load portion A are determined so that a couple is formed between the bending load portion A and the attachment plate 4 when the bending stress is borne. Thereby, a couple can be formed between the upper and lower joints of the secondary beam 2. Regarding the bending load portion A, it is preferable to determine the height H such that the cross-sectional area of the bending load portion A in the height direction is equal to the cross-sectional area of the attachment plate 4 in the width direction.

[0038] In this embodiment, the heights of the main beam 1 and the secondary beam 2 are different, and compared with the joint structure shown in FIGS. 6(a) to 6(c), the effect of simplification is particularly large by omitting the lower attachment plate. However, the present invention can be applied not only to the main beam 1 and the secondary beam 2 but also to the case where grandchild beams are arranged on both sides of the secondary beam 2, and can also be applied to the case where secondary beams intersecting the secondary beam 2 in a direction intersecting in a plane are joined to both sides of the secondary beam 2, etc., even when the heights of the steel frame beams intersecting in a plane are the same.

[0039] In this embodiment, the upper flanges of the secondary beams 2 on both sides of the main beam 1 are joined using the attachment plate 4, but by fastening the attachment plate 4 to the upper flange of the main beam 1 using the fastener 5, it is also possible to join the upper flange of the main beam 1 and the upper flange of the secondary beam 2.

[0040] Also, the shape of the overlapping portion of the plate 11 is not limited to that described in the example of FIG. 1, and can be determined variously according to the magnitudes of the bending stress and shear stress to be borne. For example, as shown in FIG. 3, the bending load portion A can be formed in an L shape projecting toward the side of the secondary beam 2. Also, when the number of fasteners 3 for bending load and the area of the bending load portion A may be small, as shown in FIG. 4, the overlapping portion of the plate 11 can be formed in a vertically long rectangular shape.

[0041] In addition, since the fastener 3 for bending load and the bending load portion A are arranged in a height range corresponding to the lower half of the web of the secondary beam 2, in the example of FIG. 1, the fastener 3 for shear load and the shear load portion are arranged in a height range corresponding to the upper half of the web of the secondary beam 2, but it is not limited to this. For example, as shown in FIG. 5, the overlapping portion of the plate 11 is formed in a horizontally long rectangular shape and provided only in a height range corresponding to the lower half of the web of the secondary beam 2, and both the fastener 3 for shear load and the fastener 3 for bending load may be provided in the overlapping portion.

[0042] In the present embodiment, a high-strength bolt is used as the bolt 31 of the fastener 3, but it is not limited to this. For example, a medium-strength bolt can also be used.

[0043] As described above, the preferred embodiments of the present invention have been described with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that those skilled in the art can conceive of various modification examples or correction examples within the scope of the technical idea disclosed in the present application, and it is naturally understood that those also belong to the technical scope of the present invention.

Explanation of Reference Numerals

[0044] 1: Girder 2: Secondary beam 3, 5: Fasteners 4: Attaching plate 10: Joining structure 11: Plate 31: Bolt

Claims

1. A joint structure for an end portion of a second steel beam arranged in a direction intersecting the first steel beam in a plane, the end portion being located on the first steel beam side, an upper flange of the second steel beam is disposed at the same height as an upper flange of the first steel beam; The upper flange of the second steel beam is joined to the upper flange of another second steel beam arranged on the opposite side of the second steel beam across the first steel beam, or to the upper flange of the first steel beam, using a splice plate and a fastener; A method for forming a joint structure in which a plate provided on a first steel beam and a web of a second steel beam are joined using a fastener arranged at an overlapping portion of the plate and the web, comprising: determining the number of bending-bearing fasteners among the fasteners to be arranged in the overlapping portion, and the height of the bending-bearing portion in which the bending-bearing fasteners are arranged, the bending-bearing fasteners being located in a height range corresponding to the lower half of the web in the overlapping portion, so that a predetermined bending stress can be borne; a step of manufacturing the plate having the bending portion and forming the joint structure using the plate; A method for forming a junction structure comprising the steps of:

2. 2. The method for forming a joint structure according to claim 1, wherein the shape of the plate is determined so that the bending load portion protrudes toward the second steel beam at the overlapping portion.

3. 2. The method for forming a joint structure according to claim 1, wherein the number of fasteners for bearing bending stress and the height of the bending stress portion are determined so that a force couple is established between the bending stress portion and the splice plate when bending stress is borne.

4. 2. The method for forming a joint structure according to claim 1, wherein the height of the bending portion is determined so that the cross-sectional area of ​​the bending portion in the height direction is equal to the cross-sectional area of ​​the splice plate in the width direction.

5. 2. The method for forming a joint structure according to claim 1, wherein the width of the first steel beam is greater than the width of the second steel beam.

6. A joint structure for an end portion of a second steel beam arranged in a direction intersecting the first steel beam in a plane, the end portion being located on the first steel beam side, an upper flange of the second steel beam is disposed at the same height as an upper flange of the first steel beam; The upper flange of the second steel beam is joined to the upper flange of another second steel beam arranged on the opposite side of the second steel beam across the first steel beam, or to the upper flange of the first steel beam, using a splice plate and a fastener; A plate provided on the first steel beam and a web of a second steel beam are joined together using a fastener disposed in an overlapping portion of the plate and the web; the fasteners disposed in the overlapping portion include bending stress fasteners; The bending-bearing fastener is disposed in a bending-bearing portion located in a height range corresponding to a lower half of the web in the overlapping portion, A joint structure characterized in that, in the overlapping portion, the bending load portion protrudes toward the second steel beam.

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