JP7811155B2 - Beam joint structure and building - Google Patents

Description

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

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, the beam connection structure disclosed in Patent Document 1 is configured so that a first beam made of H-shaped steel and a second beam made of H-shaped steel are joined 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. The compression force transmission member has fixed ends at both ends and is fixed to the bottom flanges of each 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.

Japanese Patent Application Laid-Open No. 2022-25804

The beam joint structure disclosed in Patent Document 1 is configured to transmit the 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 the 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 documents, and has yet to be seen or heard of.

The present invention aims to solve the above-mentioned problems by providing a beam joint structure and building in which the depth dimension of the first beam is equal to the depth dimension of the second beam, or the depth dimension of the first beam is smaller than the depth dimension of the second beam, and in which the bending moment generated in the second beam is transferred to the adjacent second beam.

The beam joining structure of the present invention comprises a first beam and a second beam that intersects with the first beam and is arranged on both sides of the first beam with their end faces facing each other, 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, 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, and the width dimension of the first beam is smaller than the width dimension of the second beam .

The building of the present invention is equipped with the above-mentioned beam joint structure.

In the beam joint structure and building of the present invention, the second flange portions of adjacent second beams arranged on either side of a first beam are joined by a stress transfer member located below the first lower flange. Therefore, in a configuration in which the depth dimension of the first beam is equal to or smaller than the depth dimension of the second beam, the bending moment generated in the second beam can be transferred to the adjacent second beam.

1 is a perspective view showing a beam joining structure according to a first embodiment; FIG. 2 is a longitudinal cross-sectional view of a beam joint structure according to the first embodiment, viewed from the longitudinal direction of a first beam. FIG. 2 is a longitudinal cross-sectional view of the beam joining structure according to the first embodiment, seen from the longitudinal direction of the second beam. 1 is a plan view showing a stress transfer member of a beam joint structure according to embodiment 1. FIG. FIG. 10 is a longitudinal 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. 6 is a plan view showing a stress transfer member applied to the beam joint structure shown in FIG. 5. 1 is a plan view showing an example of a building to which a beam joint structure according to embodiment 1 is applied; FIG. 10 is a longitudinal cross-sectional view of a beam joint structure according to a second embodiment of the present invention, viewed from the longitudinal direction of a first beam. FIG. 10 is a longitudinal 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.

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 a schematic illustration, and the relative size and thickness of each component are not limited to the dimensions shown. Furthermore, the size relationships between the components in the following drawings may differ from the actual ones.

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.

As shown in Figures 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. As an example, the first beam 1 is a main beam. As an example, the second beam 2 is a sub-beam. Note that both the first beam 1 and the second beam 2 may be sub-beams.

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 do not necessarily mean strictly equal, but also include cases where there is a tolerance.

As shown in Figures 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 plates 3 are arranged on both sides 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. Multiple bolt holes 30a are formed in the tip surface 30 of the gusset plate 3. Meanwhile, multiple 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 the bolts 40 passed through the bolt holes in common to each other and tightening them with nuts 41.

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 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. Although standard bolts are typically used for 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 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.

As shown in Figures 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. Also, as shown in Figure 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.

In the beam joint structure 100 according to this first embodiment, as shown in Figures 2 and 3, adjacent second beams 2, 2 are arranged on either side of the first beam 1, and the second lower flanges 22, 22 are joined together by a stress transfer member 5 arranged below the first lower flange 12.

As shown in FIG. 4, the stress transfer member 5 is made of, for example, a rectangular steel plate. The stress transfer 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 transfer member 5 in each region 50 that abuts 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 transfer member 5. The stress transfer 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 threaded through the bolt holes with nuts 61. At this time, the upper surface of the stress transfer member 5 also abuts against the lower surface of the first lower flange 12 of the first beam 1. While standard bolts are typically used as the bolts 60, high-strength bolts can also be used. Furthermore, the position and number of bolt holes 5a are not limited to the configuration shown in the figure, and can be implemented in various ways depending on the size and shape of the first beam 1 and 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 bolt joining shown in the figure. For example, the stress transfer member 5 can also be joined by welding to the second lower flange 22 of the second beam 2.

As shown in FIG. 5, 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. The reason for temporarily fastening the stress transfer member 5 to the first lower flange 12 of the first beam 1 for construction is to improve construction ease and prevent buckling of the stress transfer member 5. In this case, as shown in FIG. 6, the stress transfer member 5 has multiple bolt holes 5b formed in the region 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 in positions corresponding to the bolt holes 5b of the stress transfer member 5. The stress transfer member 5 is temporarily fastened by abutting its upper surface against the lower surface of the first lower flange 12 of the first beam 1 and fastening bolts 70 commonly passing through the bolt holes with nuts 71. The bolts 70 and nuts 71 may remain attached or may be removed after the stress transfer member 5 is joined to the second lower flange 22. The position and number of bolt holes 5b are not limited to the configuration shown in the figure, and can be implemented in various ways depending on the size and shape of the first beam 1 and second beam 2.

Furthermore, the stress transmission member 5 is not limited to the rectangular steel plate shown in the figure, but may be, for example, an angle steel, a channel steel, or a T-shaped steel. In short, the stress transmission member 5 only needs to be able to transmit stress between adjacent second beams 2 arranged on either side of the first beam 1.

As shown in FIG. 2 , in the beam connection 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 installed in the square formed by the first beam 1 and the second beam 2, and reinforcing bars 81 are placed 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.

After the first beam 1 and 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 so that the center of the bolt group consisting of multiple 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, increasing the distance between the center of the bolt group of the gusset plate 3 and the stress transfer member 5 increases the reaction force against the fixed load and increases the moment that can be supported. The number and position of the bolts 40 are determined according to the fixed load.

However, when the first beam 1 and second beam 2 are joined only by a gusset plate 3, the end of the second beam 2 is considered to be fixed by a pin, and strength design is performed as if it were 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. For this reason, 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 result in increased material costs.

As mentioned above, conventionally, in a structure in which the depth dimension of the first beam 1 is greater than the depth dimension of the second beam 2, 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 of.

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. Adjacent second beams 2, arranged on either side of the first beam 1, are joined at their second lower flanges 22 by stress transfer members 5 located 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, contributing to reduced material costs. Furthermore, the rotation angle at both ends of the second beam 2 is reduced, reducing cracking in the concrete floor slab 8.

Note that Figure 7 is a plan view that schematically illustrates an example of a building 200 to which the beam joint structure 100 according to embodiment 1 is applied. The building 200 has multiple 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 that form the lattice is formed by a girder 202. Note that the lattice is not limited to the square shown in Figure 7, and can be, for example, rectangular, triangular, diamond-shaped, etc., by appropriately changing the arrangement of the columns 201 and girders 202.

The spine beam 203 and sub-beams 204 are arranged in the inner area of the four main beams 202 that form a rectangular grid. The spine beam 203 is located in the center of the grid, and both ends are joined to two opposing main beams 202 of one of the four main beams 202.

The sub-beams 204 are arranged between two opposing girders 202 of the four girders 202 that form the grid. One end of the sub-beam 204 is joined to the spine beam 203, and the other end is joined to the girder 202 facing the spine beam 203. As an example, three sub-beams 204 are arranged in parallel between the girder 202 and the spine beam 203.

The beam joint structure 100 according to embodiment 1 can be applied to joint portion 100A where the spine beam 203 and the sub-beam 204 are joined, joint portion 100B where the main beam 202 and the sub-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 sub-beam 204. In joint portion 100B, the first beam 1 is the main beam 202, and the second beam 2 is the sub-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.

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.

The beam joint structure 101 according to the second embodiment is configured such that the width dimension of the first beam 1 is smaller than the width dimension of the second beam 2. The second beams 2, which intersect with the first beam 1 and are arranged on either side of the first beam 1, have their second lower flanges 22 joined together 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.

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.

Also, 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 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.

In the beam joint structure 101 according to the second embodiment, the stress transfer member 5 also allows the bending moment generated in the second beam 2 to be transferred 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.

The beam joint structures 100 and 101 have been described above based on the embodiments, but 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 would normally be made by a person skilled in the art, as long as they do not deviate from the technical concept.

The various aspects of this disclosure are summarized below as appendices.

(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.

(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.

(Appendix 3)
The beam joint structure described in Appendix 1, wherein the width dimension of the first beam is smaller than the width dimension of the second beam.

(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.

(Appendix 5)
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.

(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.

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

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 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 Reinforcement bar, 82 Concrete, 100, 101 Beam connection structure, 100A, 100B, 100C Connection portion, 200 Building, 201 Column, 202 Main beam, 203 Backbone beam, 204 Sub-beam, S Gap.

Claims (5)

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