Beam connection structure and building

Abstract

The objective is to provide a beam joint structure and building that transmits the bending moment generated in the second beam to an adjacent second beam in a structure where the depth of the first beam and the depth of the second beam are equal, or the depth of the first beam is smaller than the depth of the second beam. [Solution] The beam joint structure comprises a first beam and a second beam that intersects with the first beam, is positioned with its end faces facing each other on both sides of the first beam, and has its end joined to the first beam. The first beam has a first web and a first lower flange provided at the lower end of the first web. The second beam has a second web and a second lower flange provided at the lower end of the second web. Adjacent second beams positioned on either side of the first beam are joined at their second lower flanges by a stress transmission member positioned below the first lower flange, and the stress transmission member is not joined to the first lower flange.

Description

Technical Field

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

Background Art

[0002] Conventionally, the floor structure of a building is formed by arranging beams in a grid pattern and constructing a reinforced concrete floor slab thereon. For example, the beam joint structure disclosed in Patent Document 1 has a configuration in which a first beam made of H-shaped steel and a second beam made of H-shaped steel are joined via a gusset plate. The second beam is arranged with end faces facing each other on both sides of the web of the first beam. Adjacent second beams arranged with the first beam interposed therebetween are connected by a plate-shaped compressive force transmission member that penetrates the web of the first beam. Both ends of the compressive force transmission member are fixed portions and are fixed to the lower flanges of the two second beams using bolts. Thereby, the bending moment generated in the second beam is transmitted to the adjacent second beam.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The beam joint structure disclosed in Patent Document 1 is configured to transmit the bending moment generated in the second beam to the adjacent second beam in a structure where the cross-sectional dimension of the first beam is larger than the cross-sectional dimension of the second beam. That is, Patent Document 1 does not disclose a configuration for transmitting the bending moment generated at the end of the second beam to the adjacent second beam in a structure where the cross-sectional dimension of the first beam is equal to or smaller than the cross-sectional dimension of the second beam. Such a configuration is not disclosed in other documents either and has not been heard of yet.

[0005] The present invention aims to solve the above problems and to provide a beam joint structure and building in which, in a structure in which the depth dimension of the first beam and the depth dimension of the second beam are equal, or the depth dimension of the first beam is smaller than the depth dimension of the second beam, the bending moment generated in the second beam is transmitted to the adjacent 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 and is arranged with its end faces facing each other on both sides of the first beam, and whose end is joined to the first beam, wherein the first beam has a first web, a first upper flange provided at the upper end of the first web, and a first lower flange provided at the lower end of the first web, and the second beam has a second web, a second upper flange provided at the upper end of the second web, and a second lower flange provided at the lower end of the second web, wherein adjacent second beams arranged on either side of the first beam are joined at their second lower flanges by a stress transmission member located below the first lower flange, and the stress transmission member is not joined to the first lower flange.

[0007] The building according to the present invention is equipped with the above-described beam joint structure. [Effects of the Invention]

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

[0009] [Figure 1] This is a perspective view showing the beam joint structure according to Embodiment 1. [Figure 2]This is a beam joint structure according to Embodiment 1, and is a longitudinal cross-sectional view of the first beam as seen from the longitudinal direction. [Figure 3] This is a longitudinal cross-sectional view of the second beam as seen from the longitudinal direction, relating to a beam joint structure according to Embodiment 1. [Figure 4] This is a plan view showing the stress transfer member of the beam joint structure according to Embodiment 1. [Figure 5] This is a modified example of the beam joint structure according to Embodiment 1, and is a longitudinal cross-sectional view of the first beam as seen from the longitudinal direction. [Figure 6] Figure 5 is a plan view showing a stress transfer member applied to the beam joint structure. [Figure 7] This is a schematic plan view showing an example of a building to which the beam joint structure according to Embodiment 1 is applied. [Figure 8] This is a beam joint structure according to Embodiment 2, and is a longitudinal cross-sectional view of the first beam as seen from the longitudinal direction. [Figure 9] This is a modified example of the beam joint structure according to Embodiment 2, and is a longitudinal cross-sectional view of the first beam as seen from the longitudinal direction. [Modes for carrying out the invention]

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

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

[0012] In the beam joint structure 100 according to this embodiment 1, as shown in Figures 1 to 3, it 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 positioned with its longitudinal end faces facing each other on both sides of the first beam 1, 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 secondary beam. Note that both the first beam 1 and the second beam 2 may be secondary beams.

[0013] The first beam 1 is, for example, an H-shaped steel beam 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 beam 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 the same. Note that "equal depth dimensions" does not mean strictly equal, but also includes cases where there are tolerances.

[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 bolt-joining a second web 20 to the gusset plate 3 welded to the first beam 1. The gusset plates 3 are respectively arranged on both sides of the first web 10 of the first beam 1. The gusset plate 3 is welded at its periphery 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 its 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. On the other hand, a plurality of bolt holes (not shown) are formed in the second web 20 at the longitudinal end of the second beam 2. At the longitudinal end, the second beam 2 is joined to the gusset plate 3 by overlapping the tip surface 30 of the gusset plate 3 with the second web 20 and fastening bolts 40 passed through the common bolt holes with nuts 41 for bolt-joining.

[0015] Note that the bolt-joining between the gusset plate 3 and the second web 20 is configured to be biased toward the first upper flange 11 such that the center of the bolt group composed of a plurality of bolts 40 joined along the vertical direction of the first web 10 is located closer to the first upper flange 11 side than the center of the first web 10. Further, normal bolts are usually used for the bolts 40, but high-strength bolts can also be used. Also, the bolt-joining between the gusset plate 3 and the second web 20 is not limited to the illustrated configuration. For example, the tip surface 30 of the gusset plate 3 may be formed up to the vicinity of the first lower flange 12 and bolt-joined uniformly from the vicinity of the first upper flange 11 to the vicinity of the first lower flange 12.

[0016] As shown in FIGS. 1 and 2, in the state where the first beam 1 and the second beam 2 are joined, the upper surfaces of the first upper flange 11 and the second upper flange 21 are substantially flush. Also, as shown in FIG. 2, in the state where the first beam 1 and the second beam 2 are joined, the lower surfaces of the first lower flange 12 and the second lower flange 22 are substantially flush.

[0017] And in the beam joint structure 100 according to the first embodiment, as shown in FIGS. 2 and 3, adjacent second beams 2, 2 arranged sandwiching the first beam 1 are joined together at their second lower flanges 22, 22 by a stress transmission member 5 disposed below the first lower flange 12.

[0018] As shown in FIG. 4, the stress transmission member 5 is, for example, composed of a rectangular steel plate. In the stress transmission member 5, a plurality of bolt holes 5a are formed in each region 50 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 abutting on the second lower flange 22. On the other hand, in the second lower flange 22 of the second beam 2, a plurality of bolt holes (not shown) are 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 bringing the upper surface into contact with the lower surface of the second lower flange 22 of the second beam 2 and fastening bolts 60 passed through the bolt holes in common with nuts 61 for bolt connection. At this time, the upper surface of the stress transmission member 5 is also in contact with the lower surface of the first lower flange 12 of the first beam 1. Usually, ordinary bolts are used for the bolts 60, but high-strength bolts can also be used. Further, the position and number of the bolt holes 5a are not limited to the illustrated configuration, and may be implemented in various modes according to the sizes and shapes of the first beam 1 and the second beam 2. Also, the means for joining the stress transmission member 5 to the second lower flange 22 of the second beam 2 is not limited to the illustrated bolt connection. For example, the stress transmission member 5 can also be joined to the second lower flange 22 of the second beam 2 by welding.

[0019] The stress transmission member 5 may also be bolted to the first lower flange 12 of the first beam 1, as shown in Figure 5, for temporary fastening during construction, and then bolted to the second lower flange 22 of the second beam 2. The reason for temporary fastening to the first lower flange 12 of the first beam 1 is to improve workability and suppress buckling of the stress transmission member 5. In this case, as shown in Figure 6, the stress transmission member 5 has multiple bolt holes 5b formed in the region 51 that abuts against the first lower flange 12. On the other hand, 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 member 5. The stress transmission member 5 is temporarily fastened by bolting it with its upper surface abutting against the lower surface of the first lower flange 12 of the first beam 1, and fastening bolts 70, which are passed through the bolt holes in common to both, with nuts 71. The bolts 70 and nuts 71 may be left attached or removed after the stress transmission member 5 is joined to the second lower flange 22. Furthermore, the position and number of bolt holes 5b are not limited to the configuration shown in the illustration, 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 member 5 is not limited to the rectangular steel plate shown in the figure, but may be, for example, angle steel, channel steel, or T-shaped steel. In short, the stress transmission member 5 only needs to be able to transmit stress between adjacent second beams 2 that are positioned on either side of the first beam 1.

[0021] As shown in Figure 2, in the beam joint structure 100 according to this embodiment 1, 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 the like (not shown) is provided in the grid 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 deck plate. Concrete 82 is then poured onto the upper surfaces of the first beam 1, the second beam 2 and the deck plate 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 by 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 stud bolts 80, generating a bending moment.

[0022] Furthermore, after joining the first beam 1 and the second beam 2, until the concrete 82 poured onto the upper surface of the floor slab hardens, it is necessary to maintain the bending moment due to the fixed load by the bolted connection between the gusset plate 3 and the second web 20, and by the bolted connection between the stress transmission member 5 and the second lower flange 22. Therefore, in the beam joint structure 100 according to this embodiment 1, as described above, in the bolted connection between the gusset plate 3 and the second web 20, the center of the bolt group consisting of multiple bolts 40 joined along the vertical direction of the first web 10 is positioned on the first upper flange 11 side rather than the center of the first web 10, thus being configured to be biased towards the first upper flange 11 side. In other words, by increasing the distance between the center of the bolt group of the gusset plate 3 and the stress transmission member 5, the reaction force to the fixed load is increased, and the moment that can be supported is increased. The number and position 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 gusset plates 3, the end of the second beam 2 is considered to be fixed by pins and is designed to be a free end for strength. For example, when the concrete floor slab 8 is subjected to a load, a large bending moment is generated in the center of the second beam 2. Therefore, the second beam 2 is designed with 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] Conventionally, as described above, a configuration has been disclosed in which, in a structure where the depth of the first beam 1 is greater than the depth of the second beam, the bending moment generated at the end of the second beam 2 is transmitted to an adjacent second beam 2. However, a configuration has not yet been seen or heard of in a structure where the depth of the first beam 1 is equal to the depth of the second beam 2, or where the depth of the first beam 1 is smaller than the depth of the second beam 2, the bending moment generated at the end of the second beam 2 is transmitted to an adjacent second beam 2.

[0025] In the beam joint structure 100 according to this embodiment 1, as described above, the depth dimensions of the first beam 1 and the depth dimensions of the second beam 2 are configured to be the same. The adjacent second beams 2, which are positioned on either side of the first beam 1, are joined together by a stress transmission member 5 positioned below the first lower flange 12, with their second lower flanges 22 connected. 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 central part of the second beam 2. As a result, the cross-sectional shape of the second beam 2 can be reduced, which contributes to reducing material costs. In addition, the rotation angle at both ends of the second beam 2 is reduced, which reduces cracking in the concrete floor slab 8.

[0026] Figure 7 is a schematic plan view showing an example of a building 200 to which the beam joint structure 100 according to Embodiment 1 is applied. The building 200 has a plurality of columns 201, and a main beam 202 is placed between two columns 201. Both ends of the main beam 202 are joined to the columns 201. The main beam 202 is arranged to form a grid with the columns 201 as nodes. The four sides forming the grid are each formed by the main beam 202. Note that the grid is not limited to the square shown in Figure 7, and can be made into rectangles, triangles, rhombuses, etc., by appropriately changing the arrangement of the columns 201 and main beams 202.

[0027] In the area inside the four main beams 202 that form a square grid, the spine beams 203 and secondary beams 204 are arranged. The spine beams 203 are positioned in the center of the grid and both ends are joined to two opposing main beams 202 of the four main beams 202.

[0028] The secondary beams 204 are positioned between two opposing main beams 202 of the four main beams 202 that form the grid. One end of the secondary beam 204 is joined to the spine beam 203, and the other end is joined to the main beam 202 opposite to the spine beam 203. As an example, three secondary beams 204 are arranged in parallel between the main beams 202 and the spine beams 203.

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

[0030] Embodiment 2. Next, the beam joint structure 101 according to this second embodiment will be described with reference to Figures 8 and 9. Figure 8 is a longitudinal cross-sectional view of the beam joint structure 101 according to the second embodiment, viewed from the longitudinal direction of the first beam 1. Figure 9 is a modified example of the beam joint structure 101 according to the second embodiment, viewed from the longitudinal direction of the first beam 1. Note that components identical to those in the beam joint structure 100 described in the first embodiment are denoted by the same reference numerals, and their descriptions are omitted as appropriate.

[0031] The beam joint structure 101 according to this second embodiment has a configuration in which the depth dimension of the first beam 1 is smaller than the depth dimension of the second beam 2. The adjacent second beams 2, which intersect with the first beam 1 and are positioned on either side of the first beam 1, are joined together by a stress transmission member 5 positioned below the first lower flange 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 transmission member 5.

[0032] As described in Embodiment 1 above, the stress transmission member 5 may be bolted to the first lower flange 12 of the first beam 1 to perform temporary fastening for construction, and then bolted to the second lower flange 22 of the second beam 2.

[0033] Furthermore, as shown in Figure 9, the second beam 2 may be provided with a projection 23 that protrudes toward the gap S between the lower surface of the first lower flange 12 and the upper surface of the stress transmission member 5. The projection 23 is formed by extending the lower portion of the second web 20 and the second lower flange 22 along the longitudinal direction to fill the gap S. The projection 23 is provided at 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 projection 23 is not limited to the above configuration, and may be formed, for example, by attaching a separate steel material or the like to the longitudinal end face of the second beam 2. Also, the projection 23 does not need to be configured to completely fill the gap S.

[0034] In the beam joint structure 101 according to this second embodiment, the stress transmission member 5 can transmit the bending moment generated in the second beam 2 to the adjacent second beam 2, thereby reducing the bending moment and deflection in the central part of the second beam 2. As a result, the cross-sectional shape of the second beam 2 can be reduced, which contributes to reducing material costs. In addition, since the rotation angle at both ends of the second beam 2 is reduced, cracking of the concrete floor slab 8 can be reduced.

[0035] Although beam joint structures 100 and 101 have been described above based on embodiments, beam joint structures 100 and 101 are not limited to the configurations of the embodiments described above. The configurations of beam joint structures 100 and 101 described above are examples, and some of the components may be omitted, or other components may be included. In short, beam joint structures 100 and 101 include the range of design changes and application variations that are normally performed by those skilled in the art, without departing from the technical concept.

[0036] The various aspects of this disclosure are summarized below as an appendix.

[0037] (Note 1) The first beam and The system comprises a second beam that intersects with the first beam, is positioned with its end faces facing each other on both sides of the first beam, and whose end is joined to the first beam, The first beam comprises a first web, a first upper flange provided at the upper end of the first web, and a first lower flange provided at the lower end of the first web. The second beam has a second web, a second upper flange provided at the upper end of the second web, and a second lower flange provided at the lower end of the second web. The adjacent second beams, which are positioned on either side of the first beam, are joined together by a stress transmission member located below the first lower flange. The stress transmission member is not joined to the first lower flange, and is a beam joint structure.

[0038] (Note 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 equal.

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

[0040] (Note 4) The beam joint structure as described in Appendix 3, wherein the second beam is provided with a protrusion that extends toward the gap between the lower surface of the first lower flange and the upper surface of the stress transmission member.

[0041] (Note 5) The second beam is joined to the first beam via the gusset plate, by bolting the second web to the gusset plate which is joined to the first beam. The bolted connection between the gusset plate and the second web is configured to be biased toward the first upper flange, such that the center of the bolt group, which consists of multiple bolts joined along the vertical direction of the first web, is located toward the first upper flange than the center of the first web, as described in any one of the appendices 1 to 4.

[0042] (Note 6) A building equipped with a beam joint structure as described in any one of the appendices 1 to 5. [Explanation of symbols]

[0043] 1 First beam, 2 Second beam, 3 Gusset plate, 5 Stress transfer member, 5a, 5b Bolt hole, 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 Protrusion, 30 End surface, 30a Bolt hole, 40 Bolt, 41 Nut, 50 Area, 60 Bolt, 61 Nut, 70 Bolt, 71 Nut, 80 Stud bolt, 81 Reinforcement, 82 Concrete, 100, 101 Beam joint structure, 100A, 100B, 100C Joint part, 200 Building, 201 Column, 202 Main beam, 203 Back beam, 204 Secondary beam, S Gap.

Claims

1. The first beam and The system comprises a second beam that intersects with the first beam, is positioned with its end faces facing each other on both sides of the first beam, and whose end is joined to the first beam, The first beam comprises a first web, a first upper flange provided at the upper end of the first web, and a first lower flange provided at the lower end of the first web. The second beam has a second web, a second upper flange provided at the upper end of the second web, and a second lower flange provided at the lower end of the second web. The adjacent second beams, which are positioned on either side of the first beam, are joined together by a stress transmission member located below the first lower flange. The stress transmission member is not joined to the first lower flange, and is a beam joint structure.

2. The beam joint structure according to claim 1, wherein the depth dimension of the first beam and the depth dimension of the second beam are configured to be equal.

3. The beam joint structure according to claim 1, wherein the depth dimension of the first beam is smaller than the depth dimension of the second beam.

4. The beam joint structure according to claim 3, wherein the second beam is provided with a protrusion that projects toward the gap between the lower surface of the first lower flange and the upper surface of the stress transmission member.

5. The second beam is joined to the first beam via the gusset plate, by bolting the second web to the gusset plate which is joined to the first beam. The beam joint structure according to any one of claims 1 to 4, wherein the bolted joint between the gusset plate and the second web is configured to be biased toward the first upper flange side such that the center of the group of bolts, which are joined along the vertical direction of the first web, is located toward the first upper flange side than the center of the first web.

6. A building comprising the beam joint structure described in any one of claims 1 to 4.

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