Beam joint structure and building

Abstract

To provide a beam joint structure and a building which are designed to transfer a bending moment generated in a second beam to an adjacent second beam in a structure where a beam diameter of a first beam is equal to that of the second beam, or where the beam diameter of the first beam is smaller than that of the second beam.SOLUTION: A beam joint structure comprises a first beam, and a second beam that intersects the first beam and is arranged with end faces facing each other on both sides across the first beam and whose ends are joined to the first beam. The first beam has a first web, and a first lower flange provided at a lower end of the first web. The second beam has a second web, and a second lower flange provided at a lower end of the second web. Adjacent second beams arranged across the first beam are joined to each other by the second lower flange by a stress transmitting member arranged below the first lower flange.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a beam joint structure that constitutes a building and a building equipped with a beam joint structure. [Background technology]

[0002] Conventionally, the floor structure of a building is formed by arranging beams in a grid pattern and constructing a reinforced concrete floor slab on top of them. For example, a beam connection structure disclosed in Patent Document 1 is configured such that a first beam made of H-shaped steel and a second beam made of H-shaped steel are connected via gusset plates. The second beams are arranged on both sides of the web of the first beam with their end faces facing each other. Adjacent second beams arranged on either side of the first beam are connected by a plate-shaped compression force transmission member that penetrates the web of the first beam. Both ends of the compression force transmission member are fixed and are fixed to the bottom flanges of the two second beams using bolts. This allows the bending moment generated in the second beam to be transmitted to the adjacent second beam. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-25804 Summary of the Invention [Problem to be solved by the invention]

[0004] The beam joint structure disclosed in Patent Document 1 is configured to transmit a bending moment generated in a second beam to an adjacent second beam in a structure in which the depth dimension of a first beam is greater than that of a second beam. In other words, Patent Document 1 does not disclose a configuration in which a bending moment generated at the end of a second beam is transmitted to an adjacent second beam in a structure in which the depth dimension of a first beam is equal to or smaller than that of a second beam. Such a configuration has not been disclosed in any other document, and has not yet been seen or heard of.

[0005] The present invention solves the above-mentioned problems and aims to provide a beam joint structure and a building in which the bending moment generated in the second beam is transmitted to the adjacent second beam in a structure in which the depth dimension of the first beam is equal to the depth dimension of the second beam or is smaller than the depth dimension of the second beam. [Means for solving the problem]

[0006] The beam joint structure according to the present invention comprises a first beam and a second beam that intersects with the first beam, is arranged on both sides of the first beam with end faces facing each other, and has an end joined to the first beam, wherein the first beam has a first web, a first upper flange provided at an upper end of the first web, and a first lower flange provided at a lower end of the first web, and the second beam has a second web, a second upper flange provided at an upper end of the second web, and a second lower flange provided at a lower end of the second web, and the second lower flanges of adjacent second beams arranged on either side of the first beam are joined to each other by stress transfer members arranged below the first lower flanges. The width of the first beam is smaller than the width of the second beam. It is something.

[0007] The building according to the present invention includes the beam joint structure described above. [Effects of the Invention]

[0008] In the beam joint structure and building of the present invention, the second flange portions of adjacent second beams arranged on either side of the first beam are joined by a stress transfer member arranged below the first lower flange, so that in a configuration in which the depth dimension of the first beam is equal to the depth dimension of the second beam or is smaller than the depth dimension of the second beam, the bending moment generated in the second beam can be transmitted to the adjacent second beam. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a perspective view showing a beam joint structure according to a first embodiment. [Figure 2]1 is a longitudinal cross-sectional view of a beam joint structure according to the first embodiment, seen from the longitudinal direction of a first beam. [Figure 3] 3 is a longitudinal cross-sectional view of the beam joint structure according to the first embodiment, seen from the longitudinal direction of the second beam. FIG. [Figure 4] 1 is a plan view showing a stress transmission member of a beam joint structure according to the first embodiment. [Figure 5] FIG. 10 is a vertical cross-sectional view of a modified example of the beam joint structure according to the first embodiment, seen from the longitudinal direction of the first beam. [Figure 6] FIG. 6 is a plan view showing a stress transfer member applied to the beam joint structure shown in FIG. 5. [Figure 7] 1 is a plan view showing an example of a building to which a beam joint structure according to a first embodiment is applied. [Figure 8] FIG. 10 is a longitudinal cross-sectional view of a beam joint structure according to a second embodiment, seen from the longitudinal direction of a first beam. [Figure 9] FIG. 10 is a vertical cross-sectional view of a modified example of the beam joint structure according to the second embodiment, seen from the longitudinal direction of the first beam. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to the embodiments described below. Each figure is a schematic illustration, and the relative size and thickness of each member are not limited to the dimensions shown. Furthermore, the size relationships between each component member in the following drawings may differ from the actual ones.

[0011] Embodiment 1 FIG. 1 is a perspective view showing a beam joint structure 100 according to the first embodiment. FIG. 2 is a longitudinal cross-sectional view of the beam joint structure 100 according to the first embodiment, seen from the longitudinal direction of the first beam 1. FIG. 3 is a longitudinal cross-sectional view of the beam joint structure 100 according to the first embodiment, seen from the longitudinal direction of the second beam 2. FIG. 4 is a plan view showing a stress transfer member 5 of the beam joint structure 100 according to the first embodiment. FIG. 5 is a modified example of the beam joint structure 100 according to the first embodiment, seen from the longitudinal direction of the first beam 1. FIG. 6 is a plan view showing a stress transfer member 5 applied to the beam joint structure 100 shown in FIG. 5.

[0012] As shown in Figs. 1 to 3, the beam joint structure 100 according to the first embodiment is a joint structure of a first beam 1 and a second beam 2. The second beam 2 intersects with the first beam 1 and is arranged on both sides of the first beam 1 with its longitudinal end faces facing each other, and its end is joined to the first beam 1. The first beam 1 is, for example, a main beam. The second beam 2 is, for example, a sub-beam. Note that both the first beam 1 and the second beam 2 may be sub-beams.

[0013] The first beam 1 is, for example, an H-shaped steel, and has a first web 10, a first upper flange 11 provided at the upper end of the first web 10, and a first lower flange 12 provided at the lower end of the first web 10. The second beam 2 is also, for example, an H-shaped steel, and has a second web 20, a second upper flange 21 provided at the upper end of the second web 20, and a second lower flange 22 provided at the lower end of the second web 20. The depth dimensions of the first beam 1 and the second beam 2 are configured to be equal. Note that equal depth dimensions are not limited to being strictly equal, but also include cases where there is a tolerance.

[0014] As shown in FIGS. 1 to 3 , the second beam 2 is joined to the first beam 1 via the gusset plate 3 by bolting the second web 20 to the gusset plate 3, which is welded to the first beam 1. The gusset plate 3 is disposed on each side of the first web 10 of the first beam 1. The periphery of the gusset plate 3 is welded to the first web 10, the lower surface of the first upper flange 11, and the upper surface of the first lower flange 12 of the first beam 1, and the tip surface 30 protrudes toward the longitudinal end of the second beam 2. A plurality of bolt holes 30a are formed in the tip surface 30 of the gusset plate 3. Meanwhile, a plurality of bolt holes (not shown) are formed in the second web 20 at the longitudinal end of the second beam 2. The second beam 2 is joined to the gusset plate 3 by overlapping the tip surface 30 of the gusset plate 3 on the second web 20 at the longitudinal end, and by fastening bolts 40 passed through both bolt holes together with nuts 41.

[0015] The bolted connection between the gusset plate 3 and the second web 20 is configured so that the center of a group of bolts consisting of multiple bolts 40 joined along the up-down direction of the first web 10 is biased toward the first upper flange 11 so that it is located closer to the first upper flange 11 than the center of the first web 10. Although normal bolts are usually used as the bolts 40, high-strength bolts can also be used. The bolted connection between the gusset plate 3 and the second web 20 is not limited to the configuration shown in the figure. For example, the tip end surface 30 of the gusset plate 3 may be formed up to the vicinity of the first lower flange 12, and the bolts may be uniformly connected from the vicinity of the first upper flange 11 to the vicinity of the first lower flange 12.

[0016] 1 and 2, when the first beam 1 and the second beam 2 are joined, the upper surface of the first upper flange 11 and the upper surface of the second upper flange 21 are approximately flush with each other. Also, as shown in Fig. 2, when the first beam 1 and the second beam 2 are joined, the lower surface of the first lower flange 12 and the lower surface of the second lower flange 22 are approximately flush with each other.

[0017] In the beam joining structure 100 according to this embodiment 1, as shown in Figures 2 and 3, adjacent second beams 2, 2 arranged on either side of the first beam 1 are joined to each other by stress transfer members 5 arranged below the first lower flange 12, with the second lower flanges 22, 22 joined to each other.

[0018] As shown in FIG. 4 , the stress transmission member 5 is made of, for example, a rectangular steel plate. The stress transmission member 5 has multiple bolt holes 5a formed in each region 50 that is joined to the second lower flange 22. For example, the bolt holes 5a shown in FIG. 4 are formed in two rows along the longitudinal direction of the stress transmission member 5 in each region 50 that abuts against the second lower flange 22. Meanwhile, the second lower flange 22 of the second beam 2 has multiple bolt holes (not shown) formed at positions corresponding to the bolt holes 5a of the stress transmission member 5. The stress transmission member 5 is joined to the second lower flange 22 by abutting its upper surface against the lower surface of the second lower flange 22 of the second beam 2 and fastening bolts 60 that are commonly passed through the bolt holes with nuts 61. At this time, the upper surface of the stress transmission member 5 also abuts against the lower surface of the first lower flange 12 of the first beam 1. Although standard bolts are usually used as the bolts 60, high-strength bolts can also be used. Furthermore, the positions and number of bolt holes 5a are not limited to the illustrated configuration, and may be implemented in various ways depending on the size and shape of the first beam 1 and the second beam 2. Furthermore, the means for joining the stress transfer member 5 to the second lower flange 22 of the second beam 2 is not limited to the illustrated bolt joining. For example, the stress transfer member 5 can also be joined to the second lower flange 22 of the second beam 2 by welding.

[0019] As shown in FIG. 5 , the stress transmission members 5 may be bolted to the first lower flange 12 of the first beam 1, temporarily fastened for construction, and then bolted to the second lower flange 22 of the second beam 2. The reason for temporarily fastening the stress transmission members 5 to the first lower flange 12 of the first beam 1 for construction is to improve construction ease and suppress buckling of the stress transmission members 5. In this case, as shown in FIG. 6 , the stress transmission members 5 have multiple bolt holes 5b formed in an area 51 abutting the first lower flange 12. Meanwhile, the first lower flange 12 of the first beam 1 has multiple bolt holes (not shown) formed at positions corresponding to the bolt holes 5b of the stress transmission members 5. The stress transmission members 5 are temporarily fastened by abutting their upper surfaces against the lower surface of the first lower flange 12 of the first beam 1 and fastening bolts 70 commonly inserted through the bolt holes with nuts 71. The bolts 70 and nuts 71 may remain attached or may be removed after the stress transmission members 5 are joined to the second lower flange 22. The positions and number of bolt holes 5b are not limited to the configuration shown in the figure, and may be implemented in various ways depending on the size and shape of the first beam 1 and the second beam 2.

[0020] Furthermore, the stress transmission members 5 are not limited to the rectangular steel plates shown in the drawings, and may be, for example, angle steel, channel steel, T-shaped steel, etc. In short, it is sufficient that the stress transmission members 5 are capable of transmitting stress between adjacent second beams 2 arranged on either side of the first beam 1.

[0021] As shown in FIG. 2 , in the beam-joint structure 100 according to the first embodiment, stud bolts 80 are erected on the upper surface of the first upper flange 11 of the first beam 1 and the upper surface of the second upper flange 21 of the second beam 2. A deck plate or other floor slab (not shown) is provided in the square formed by the first beam 1 and the second beam 2, and reinforcing bars 81 are arranged above the first beam 1, the second beam 2, and the floor slab. Concrete 82 is then poured onto the upper surfaces of the first beam 1, the second beam 2, and the floor slab to form a concrete floor slab 8. The concrete floor slab 8 is connected to the first beam 1 and the second beam 2 by stud bolts 80 and reinforced with reinforcing bars 81. When the concrete floor slab 8 is subjected to a load, the load is transmitted to the first beam 1 and the second beam 2 via the reinforcing bars 81 and the stud bolts 80, generating a bending moment.

[0022] After the first beam 1 and the second beam 2 are joined, the bending moment due to the fixed load must be supported by the bolted joint between the gusset plate 3 and the second web 20 and the bolted joint between the stress transfer member 5 and the second lower flange 22 until the concrete 82 poured on the upper surface of the deck hardens. Therefore, in the beam joint structure 100 according to the first embodiment, as described above, the bolted joint between the gusset plate 3 and the second web 20 is configured such that the center of the bolt group consisting of the plurality of bolts 40 joined along the vertical direction of the first web 10 is biased toward the first upper flange 11 so that it is located closer to the first upper flange 11 than the center of the first web 10. In other words, by increasing the distance between the center of the bolt group of the gusset plate 3 and the stress transfer member 5, the reaction force against the fixed load is increased, thereby increasing the moment that can be supported. The number and positions of the bolts 40 are determined according to the fixed load.

[0023] Incidentally, when the first beam 1 and the second beam 2 are joined only by the gusset plate 3, the end of the second beam 2 is considered to be fixed by a pin and is designed as a free end. For example, when the concrete floor slab 8 is subjected to a load, a large bending moment occurs in the center of the second beam 2. Therefore, the second beam 2 is designed to have a larger cross-sectional shape to accommodate this bending moment. However, increasing the cross-sectional shape of the second beam 2 could increase material costs.

[0024] As mentioned above, in the past, in a structure in which the depth dimension of the first beam 1 is larger than the depth dimension of the second beam, a configuration has been disclosed in which the bending moment occurring at the end of the second beam 2 is transmitted to the adjacent second beam 2. However, in a structure in which the depth dimension of the first beam 1 is equal to the depth dimension of the second beam 2 or is smaller than the depth dimension of the second beam 2, a configuration in which the bending moment occurring at the end of the second beam 2 is transmitted to the adjacent second beam 2 has not yet been seen or heard.

[0025] In the beam joint structure 100 according to the first embodiment, as described above, the depth dimensions of the first beam 1 and the second beam 2 are configured to be equal. The second lower flanges 22 of the adjacent second beams 2, which are arranged on either side of the first beam 1, are joined together by stress transfer members 5 disposed below the first lower flanges 12. This allows the bending moment generated in the second beam 2 to be transmitted to the adjacent second beam 2, thereby reducing the bending moment and deflection in the center of the second beam 2. This allows the cross-sectional shape of the second beam 2 to be smaller, which contributes to reducing material costs. Furthermore, the rotation angle at both ends of the second beam 2 is reduced, which reduces cracking in the concrete floor slab 8.

[0026] FIG. 7 is a plan view schematically showing an example of a building 200 to which the beam joint structure 100 according to the first embodiment is applied. The building 200 has a plurality of columns 201, and a girder 202 is arranged between two columns 201. Both ends of the girder 202 are joined to the columns 201. The girder 202 is arranged to form a lattice with the columns 201 as nodes. Each of the four sides forming the lattice is formed by a girder 202. The lattice is not limited to the square shown in FIG. 7, and can be, for example, a rectangle, a triangle, a rhombus, or the like, by appropriately changing the arrangement of the columns 201 and the girders 202.

[0027] The spine beam 203 and the minor beams 204 are arranged in the inner area of ​​the four girders 202 that form the rectangular grid. The spine beam 203 is arranged in the center of the grid, and both ends of the spine beam 203 are joined to two opposing girders 202 of one of the four girders 202.

[0028] The minor beam 204 is arranged between two opposing major beams 202 of the four major beams 202 that form the lattice. One end of the minor beam 204 is joined to the spine beam 203, and the other end is joined to the major beam 202 that faces the spine beam 203. As an example, three minor beams 204 are arranged in parallel between the major beam 202 and the spine beam 203.

[0029] The beam joint structure 100 according to the first embodiment can be applied to a joint 100A where a spine beam 203 and a minor beam 204 are joined, a joint 100B where a main beam 202 and a minor beam 204 are joined, and a joint 100C where a main beam 202 and a spine beam 203 are joined. In the joint 100A, the first beam 1 is the spine beam 203, and the second beam 2 is the minor beam 204. In the joint 100B, the first beam 1 is the main beam 202, and the second beam 2 is the minor beam 204. In the joint 100C, the first beam 1 is the main beam 202, and the second beam 2 is the spine beam 203.

[0030] Embodiment 2 Next, a beam joint structure 101 according to the second embodiment will be described with reference to Fig. 8 and Fig. 9. Fig. 8 is a longitudinal cross-sectional view of the beam joint structure 101 according to the second embodiment, seen from the longitudinal direction of the first beam 1. Fig. 9 is a modified example of the beam joint structure 101 according to the second embodiment, seen from the longitudinal direction of the first beam 1. Note that the same components as those in the beam joint structure 100 described in the first embodiment will be given the same reference numerals, and their description will be omitted as appropriate.

[0031] In the beam joint structure 101 according to the second embodiment, the width dimension of the first beam 1 is smaller than the width dimension of the second beam 2. The second beams 2 that intersect with the first beam 1 and are arranged on either side of the first beam 1 are joined at their second lower flanges 22 by stress transfer members 5 arranged below the first lower flanges 12. A gap S is formed between the lower surface of the first lower flange 12 of the first beam 1 and the upper surface of the stress transfer member 5.

[0032] As described in the first embodiment above, the stress transfer member 5 may be bolted to the first lower flange 12 of the first beam 1, temporarily fastened for construction, and then bolted to the second lower flange 22 of the second beam 2.

[0033] Furthermore, as shown in FIG. 9 , the second beam 2 may be provided with a convex portion 23 that protrudes toward the gap S between the lower surface of the first lower flange 12 and the upper surface of the stress transfer member 5. The convex portion 23 is configured by extending the lower portion of the second web 20 and the second lower flange 22 along the longitudinal direction so as to fill the gap S. The convex portion 23 is provided on both ends of the second beam 2. This makes it possible to suppress buckling of the first beam 1 and the second beam 2. Note that the convex portion 23 is not limited to the above configuration, and may be formed, for example, by attaching a separate steel member or the like to the longitudinal end face of the second beam 2. Furthermore, the convex portion 23 does not need to be configured to completely fill the gap S.

[0034] In the beam joint structure 101 according to the second embodiment, the stress transfer member 5 can also transfer the bending moment generated in the second beam 2 to the adjacent second beam 2, thereby reducing the bending moment and deflection in the center of the second beam 2. This allows the cross-sectional shape of the second beam 2 to be smaller, which contributes to reducing material costs. Furthermore, the rotation angle at both ends of the second beam 2 is reduced, which reduces cracks in the concrete floor slab 8.

[0035] Although the beam joint structures 100 and 101 have been described above based on the embodiments, the beam joint structures 100 and 101 are not limited to the configurations of the above-described embodiments. The configurations of the beam joint structures 100 and 101 described above are merely examples, and some of the components may be omitted or other components may be included. In short, the beam joint structures 100 and 101 include a range of design modifications and application variations that are normally made by those skilled in the art, as long as they do not deviate from the technical concept thereof.

[0036] Various aspects of the present disclosure are summarized below as appendices.

[0037] (Appendix 1) The first beam and a second beam that intersects with the first beam, is disposed on both sides of the first beam with end faces facing each other, and has an end joined to the first beam; The first beam has a first web, a first upper flange provided at an upper end of the first web, and a first lower flange provided at a lower end of the first web, the second beam has a second web, a second upper flange provided at an upper end of the second web, and a second lower flange provided at a lower end of the second web, A beam joining structure in which the adjacent second beams arranged on either side of the first beam have their second lower flanges joined together by stress transfer members arranged below the first lower flanges.

[0038] (Appendix 2) The beam joint structure described in Appendix 1, wherein the depth dimensions of the first beam and the depth dimensions of the second beam are configured to be equal.

[0039] (Appendix 3) A beam joint structure as described in Appendix 1, wherein the width dimension of the first beam is smaller than the width dimension of the second beam.

[0040] (Appendix 4) A beam joint structure as described in Appendix 3, wherein the second beam has a protrusion that protrudes toward the gap between the lower surface of the first lower flange and the upper surface of the stress transfer member.

[0041] (Appendix 5) 4. The beam joint structure according to any one of claims 1 to 3, wherein the stress transfer member is bolted to the first lower flange.

[0042] (Appendix 6) The second beam is joined to the first beam via the gusset plate by bolting the second web to the gusset plate joined to the first beam, A beam connection structure described in any one of Appendices 1 to 5, wherein the bolt connection between the gusset plate and the second web is configured so that the center of a group of bolts consisting of multiple bolts joined along the vertical direction of the first web is biased toward the first upper flange so that it is located closer to the first upper flange than the center of the first web.

[0043] (Appendix 7) A building comprising a beam joint structure according to any one of appendices 1 to 6. [Explanation of symbols]

[0044] 1 first beam, 2 second beam, 3 gusset plate, 5 stress transfer member, 5a, 5b bolt holes, 8 concrete floor slab, 10 first web, 11 first upper flange, 12 first lower flange, 20 second web, 21 second upper flange, 22 second lower flange, 23 convex portion, 30 tip surface, 30a bolt hole, 40 bolt, 41 nut, 50 area, 60 bolt, 61 nut, 70 bolt, 71 nut, 80 stud bolt, 81 reinforcing bar, 82 concrete, 100, 101 beam connection structure, 100A, 100B, 100C connection portion, 200 building, 201 column, 202 main beam, 203 spine beam, 204 minor beam, S gap.

Claims

1. The first beam and a second beam that intersects with the first beam, is disposed on both sides of the first beam with end faces facing each other, and has an end joined to the first beam; The first beam has a first web, a first upper flange provided at an upper end of the first web, and a first lower flange provided at a lower end of the first web, the second beam has a second web, a second upper flange provided at an upper end of the second web, and a second lower flange provided at a lower end of the second web, The second beams adjacent to each other and disposed on either side of the first beam have second lower flanges joined to each other by stress transmission members disposed below the first lower flanges, A beam joint structure, wherein the width of the first beam is smaller than the width of the second beam.

2. The beam joint structure according to claim 1 , wherein the second beam is provided with a protrusion that protrudes toward the gap between the lower surface of the first lower flange and the upper surface of the stress transfer member.

3. The beam joint structure according to claim 1 or 2, wherein the stress transfer member is bolted to the first lower flange.

4. The second beam is joined to the first beam via the gusset plate by bolting the second web to the gusset plate joined to the first beam, A beam connection structure as described in claim 1 or 2, wherein the bolt connection between the gusset plate and the second web is configured so that the center of a group of bolts consisting of multiple bolts joined along the vertical direction of the first web is biased toward the first upper flange so that it is located closer to the first upper flange than the center of the first web.

5. A building comprising the beam joint structure according to claim 1 or 2.

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