Column-beam joint construction

Abstract

To provide a column-beam connection structure in which an SRC beam end is located at an end of an S beam formed by H-beams, and the SRC beam end and an RC column are connected, and which can lower a beam depth of the SRC beam end as much as possible even when a span of the S beam is long, while eliminating need for welding work on the SRC beam end, etc.SOLUTION: There is provided a column-beam connection structure 100 of an RC column 40 made of reinforced concrete and an S-beam 10 formed of H-beam steel, in which: an end face of the S-beam 10 extends to a side face or near the side face of the RC column 40; and a predetermined section of an end of the S-beam 10 is an SRC beam end 20 that is steel frame reinforced concrete in which an RC structure 21 is integrally formed around the S-beam 10; a steel plate 60 is bolted directly or indirectly to at least an upper flange 12 of the S-beam 10; and a part of the steel plate 60 is embedded in the RC column 40.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a beam-column joint structure. [Background technology]

[0002] Office buildings, commercial facilities, logistics facilities, hospitals, and other buildings with large, column-free spaces often employ steel (S) beams, which are typically made of H-shaped steel beams and are generally lighter than reinforced concrete (RC) beams. These structures include buildings with steel-framed (S) columns and hybrid structures in which reinforced concrete (RC) columns are joined to S beams. Because RC columns have higher compressive strength than S columns and are less expensive to construct, buildings with RC columns and S beams are ideal for stably supporting ceilings in large spaces with long beam spans, for example, because construction costs are as low as possible. More specifically, in these structures, RC beams, which are relatively inexpensive to construct, can be used in spaces with short spans.

[0003] Even in spaces where the longest possible beam span is desired, there is a limit to the length of steel beams, and it is often difficult for the steel beams alone to support the stress at the ends of long steel beams. Furthermore, due to the high construction costs (material costs) of steel beams as mentioned above, the ends where steel beams connect to columns are often made of steel-reinforced concrete (SRC) beam ends. This effectively supports the stress at the beam ends while transferring it to the RC column, while the center of the beam is made of steel beams. This allows for a longer beam span while still supporting the stress at the beam ends. However, even with the adoption of such hybrid beams, the beam height at the ends of long-span SRC beams can become so high that they cannot fit in the ceiling.

[0004] For the above reasons, in the case of a column-beam joint structure in which an SRC beam end is located at the end of an S beam formed by H-shaped steel and the SRC beam end is joined to an RC column, it is desirable to have a column-beam joint structure in which the beam depth of the SRC beam end can be made as low as possible so that it can be placed in the ceiling, even if the span of the S beam is long.

[0005] Patent Document 1 proposes a mixed structural beam that includes a pair of reinforced concrete sections that protrude inward from a pair of reinforced concrete columns, and steel frame sections embedded at both ends in the reinforced concrete sections. In this mixed structural beam, rod-shaped joints that protrude outward in the axial direction and are joined integrally to the columns are provided at both ends of the steel frame sections.

[0006] More specifically, in a steel frame part that is an H-shaped steel beam, the joint is an anchor bolt or rebar whose rear end is fixed by welding to at least one of a pair of upper and lower flange parts of the steel frame part, and which has an anchoring part that is fixed to the column at least on the tip side in the protruding direction. Another type of joint is one in which a long nut is fixed to the flange part by welding, and the anchor bolt is screwed onto the long nut at its rear end. After the anchor bolt is screwed onto the long nut, the inside of the nut is filled with grout or adhesive, thereby integrating the long nut and the anchor bolt. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-291636 Summary of the Invention [Problem to be solved by the invention]

[0008] By applying the mixed structural beam described in Patent Document 1, it is possible to provide a mixed structural beam that can be constructed reliably and easily without joining the steel frame section and the reinforcing bars of the reinforced concrete section. However, because anchor bolts, reinforcing bars, and long nuts (cap nuts) are welded to both ends of the steel frame section in advance and protruded to the sides, there is an issue that transportability (ease of swinging and installation, including position adjustment) is poor when transporting and installing the steel beam on site.

[0009] Another issue is that welding fastening work requires qualified welders, and because cap nuts, grout, and adhesives are specialized products, they are generally expensive, meaning that production using them requires additional qualified personnel.

[0010] Furthermore, because the above-mentioned manufacturing using welders, grout, etc. is generally performed in advance by a fabrication facility, orders must be placed with the fabrication facility by calculating backwards from the time of on-site assembly. This creates issues such as lengthening the pre-processing, including the need to ensure a curing period for manufacturing, transportation, and hardening of grout, etc., and the lost time required for these processes.

[0011] The present invention was made in consideration of the above-mentioned problems, and relates to a column-beam connection structure in which an SRC beam end is located at the end of an S beam formed from H-shaped steel, and the SRC beam end is connected to an RC column.The object of the present invention is to provide a column-beam connection structure that eliminates the need for welding work, etc., on the SRC beam end, and can keep the beam depth of the SRC beam end as low as possible even when the S beam span is long. [Means for solving the problem]

[0012] In order to achieve the above object, one aspect of the column-beam joint structure according to the present invention is as follows: This is a column-beam joint structure between a reinforced concrete column and an S beam formed by H-shaped steel. The end face of the S beam extends to the side face of the RC column or to the vicinity of the side face, A predetermined section of the end of the S beam is an SRC beam end made of steel reinforced concrete, with an RC structure integrally formed around the S beam, A steel plate is bolted directly or indirectly to at least the upper flange of the S beam, and a portion of the steel plate is embedded in the RC column.

[0013] According to this method, steel plates are bolted directly or indirectly to the upper flanges of the steel beams that make up the SRC beam ends, and a portion of the steel plate is embedded in the RC column. This eliminates the need for special skills such as welding for the SRC beam ends, and allows the steel plates to bear a portion of the bending moment that occurs at the SRC beam ends. This reduces the burden of the bending moment on the RC structure at the SRC beam ends, making it possible to minimize the beam depth of the RC structure (SRC beam ends). As a result, even if the S beam span is long, the SRC beam ends can be placed in a standard ceiling space.

[0014] Here, "the end face of the steel beam extends to or near the side face of the RC column" includes both cases where the end face of the steel beam abuts (is continuous with) the side face of the RC column and the end face of the steel beam are separate. Even in the latter case, the integrity (continuity) of the RC column and the steel beam is ensured by embedding a portion of the steel plate connected to, for example, the top flange of the steel beam in the RC column. Furthermore, "the steel plate is bolted to at least the top flange of the steel beam" includes not only the steel plate bolted to the top flange but also the steel plate bolted to both the top and bottom flanges. As the steel beam becomes longer, the end of the SRC beam experiences a dominant upward tensile bending moment. Therefore, a steel plate must be connected to the top flange to resist this bending moment.

[0015] On the other hand, when the beam-column joint structure is displaced significantly during an earthquake, a downward tensile bending moment may occur at the end of the SRC beam, and if this downward tensile bending moment is larger than the normal upward tensile bending moment, a downward tensile bending moment will occur in total at the end of the SRC beam. Therefore, if such an analysis result is obtained at the design stage, the required amount of steel plate is bolted to both the top flange and the bottom flange.

[0016] Furthermore, "the steel plate is bolted directly or indirectly to at least the upper flange of the S-beam" means that it includes a form in which the steel plate is bolted directly to the upper flange, etc., as well as a form in which the steel plate is indirectly fixed to the upper flange, etc. by being fixed to a fixing member that is directly fixed to the upper flange, etc.

[0017] Another aspect of the column-beam joint structure according to the present invention is as follows: A steel plate is bolted directly or indirectly to the bottom flange of the S beam, and a portion of the steel plate is embedded in the RC column.

[0018] According to this aspect, since steel plates are bolted directly or indirectly to both the upper flange and the lower flange, when a total downward tensile bending moment occurs at the end of the SRC beam due to the downward tensile bending moment caused by displacement during an earthquake, a beam-column connection structure is obtained in which the end of the SRC beam can withstand both the normal upward tensile bending moment and the downward tensile bending moment during an earthquake. For example, depending on the analysis results, the steel plates may be installed in a manner that the amount of steel is relatively greater in the upper flange than in the lower flange, or the steel plates may be installed so that the amount of steel is the same in the upper flange and the lower flange.

[0019] In another aspect of the column-beam joint structure according to the present invention, The steel plate has a width shorter than the pitch of the main column reinforcement of the RC column, and is sized so as not to interfere with the shear reinforcement and the main column reinforcement of the RC column.

[0020] According to this embodiment, the steel plate embedded in the RC column has a width shorter than the pitch of the main column reinforcement in the RC column and has dimensions that do not interfere with the shear reinforcement and main column reinforcement in the RC column. This allows part of the steel plate to be smoothly installed between the main column reinforcement and shear reinforcement in the reinforced RC column, thereby efficiently forming a beam-column joint structure.

[0021] In another aspect of the column-beam joint structure according to the present invention, A stud dowel is attached to the portion of the steel plate that is embedded in the RC column.

[0022] According to this embodiment, by attaching a stud dowel to the part where the steel plate is embedded in the RC column, the pull-out resistance of the steel plate from the RC column can be improved when a bending moment or shear force acts on the end of the SRC beam.

[0023] Another aspect of the column-beam joint structure according to the present invention is as follows: A plurality of the steel plates are placed on the upper surface of the upper flange and joined by bolts.

[0024] According to this embodiment, multiple steel plates are placed on the upper surface of the upper flange and bolted together, so that the height of the steel plates that resist the generally dominant upper tensile bending moment can be increased by the thickness of the upper flange.By increasing the bending moment borne by the steel plates (bending moment other than that borne by the RC structure), the beam depth of the SRC beam end can be reduced.

[0025] Another aspect of the column-beam joint structure according to the present invention is as follows: A plurality of the steel plates are placed on the underside of the upper flange and joined by bolts.

[0026] According to this embodiment, multiple steel plates are placed on the underside of the upper flange and bolted together, thereby preventing interference between the upper end main reinforcement of the SRC beam end above the upper flange and the steel plates.

[0027] Another aspect of the column-beam joint structure according to the present invention is as follows: The steel plate is characterized in that it has a U-shape or a comb-teeth shape in plan view and includes a plurality of strips that are embedded in the RC column.

[0028] According to this embodiment, the steel plate has a plurality of rectangular pieces that are U-shaped or comb-shaped in plan view and are embedded in the RC column, thereby increasing the bending moment borne by the steel plate and reducing the beam depth of the end of the SRC beam.

[0029] Another aspect of the column-beam joint structure according to the present invention is as follows: It is characterized by comprising a steel block that is U-shaped in cross section and clamps the upper flange from the side and is bolted to the upper flange, and a steel plate that extends from the steel block and is embedded in the RC column.

[0030] According to this aspect, the steel block, which is U-shaped in cross section, is bolted while sandwiching the upper flange from the sides, thereby increasing the fixing strength between the upper flange and the unit body (e.g., an integrally molded product) of the steel block and steel plate, compared to when the steel plate is bolted directly to the upper flange. Note that this form in which a member other than the steel plate is bolted to the upper flange is a form in which the steel plate is "bolted indirectly to the upper flange."

[0031] Another aspect of the column-beam joint structure according to the present invention is as follows: The entire RC column, including the joint where the SRC beam end is joined, is a RC column constructed on site.

[0032] According to this embodiment, the entire RC column, including the joint where the SRC beam end is joined, is an on-site constructed RC column, which makes it possible to construct a column-beam joint structure with as low a beam depth as possible at the SRC beam end under efficient construction.

[0033] Another aspect of the column-beam joint structure according to the present invention is as follows: The joint to which the end of the SRC beam is joined is an RC joint constructed on site, and a PCa column made of precast concrete is joined to the RC joint.

[0034] According to this embodiment, the joint to which the SRC beam end is joined is an RC joint constructed on site, and a precast concrete PCa column is joined to the RC joint, making it possible to more efficiently construct a column-beam joint structure in which the beam depth of the SRC beam end is as low as possible. [Effects of the Invention]

[0035] As can be understood from the above explanation, according to the column-beam connection structure of the present invention, an SRC beam end is located at the end of an S beam formed from H-shaped steel, and in the column-beam connection structure in which the SRC beam end is connected to an RC column, welding work etc. for the SRC beam end is not required, and the beam depth of the SRC beam end can be made as low as possible even when the span of the S beam is long. [Brief explanation of the drawings]

[0036] [Figure 1] 1 is a perspective view of an example of a hybrid frame having a beam-column joint structure according to an embodiment. [Figure 2] FIG. 1 is a longitudinal cross-sectional view of an example of a beam-column joint structure according to an embodiment, showing the bending moment borne by the end of an S beam and an SRC beam and the steel plate in a hybrid beam. [Figure 3] FIG. 1 is a perspective view of an example of a joining configuration between an S beam and a steel plate. [Figure 4] FIG. 10 is a perspective view of another example of a joining form between an S beam and a steel plate. [Figure 5] FIG. 10 is a perspective view of yet another example of a joining configuration between an S beam and a steel plate. [Figure 6] FIG. 10 is a perspective view of yet another example of a joining configuration between an S beam and a steel plate. [Figure 7] FIG. 10 is a perspective view of yet another example of a joining configuration between an S beam and a steel plate. DETAILED DESCRIPTION OF THE INVENTION

[0037] Hereinafter, an example of a column-beam joint structure according to an embodiment will be described together with a hybrid frame with reference to the accompanying drawings. Note that in this specification and drawings, substantially identical components may be designated by the same reference numerals to avoid redundant description.

[0038] [Embodiment] <Hybrid structure> First, an example of a hybrid frame having a column-beam joint structure according to an embodiment will be described with reference to Fig. 1. Here, Fig. 1 is a perspective view of an example of a hybrid frame having a column-beam joint structure according to an embodiment, showing the first floor and a part of the second floor.

[0039] The hybrid frame 200 is a frame that has a wide space without columns and is used to form buildings such as office buildings, commercial facilities, logistics facilities, hospitals, etc., and is equipped with RC columns 40 and S beams 10, which are of different structural types.

[0040] The illustrated hybrid frame 200 has a wide space SP1 with a long beam span t1 and a narrow (ordinary) space SP2 with a short beam span t2, which is a common configuration found in office buildings, for example.

[0041] The RC column 40A on the lower floor (the first floor in the illustrated example) and the RC column 40B on the upper floor (the second floor in the illustrated example) form a continuous RC column via an RC joint 50, and the end of the hybrid beam 30, which is the main beam, is joined to the RC joint 50 to form a column-beam joint structure 100.

[0042] The upper and lower RC columns 40B, 40A and the RC joint 50 may all be constructed on-site as RC members, or only the RC joint 50 connected to the hybrid beam 30 may be constructed on-site as RC members, and the RC columns 40B, 40A may be PCa columns made of precast concrete members. In the latter case, the construction period of the hybrid frame 200 can be shortened.

[0043] The hybrid beam 30, which is the main girder of the large space SP1, has an S beam 10 in the center and an SRC beam end portion 20 on the end side (the RC joint 50 side). The SRC beam end portion 20 is provided within a range of a predetermined section length t3 from the end of the hybrid beam 30, and is constructed by embedding the S beam 10 in an RC structure 21 (see Figure 2).

[0044] The main beam 90 in the narrow space SP2 is an RC beam, and the minor beams 95 in the wide space SP1 and the narrow space SP2 are relatively thin RC beams.

[0045] In this way, the hybrid frame 200 is a rational and economical structural frame that applies various types of beams and columns to buildings with large spaces.

[0046] Although detailed illustrations are omitted, the hybrid beam 30 is accommodated in the attic space between the ceiling material on the first floor and the floor material on the second floor, but if the bending moment generated in the hybrid beam 30, particularly in the SRC beam end 20 due to normal loads or earthquake loads, becomes too high in beam depth t4, the SRC beam end 20 may no longer fit in the attic space. The column-beam joint structure 100 that constitutes the hybrid frame 200 is a joint structure that makes it possible to accommodate the SRC beam end 20 in the attic space by making the beam depth of the SRC beam end 20 as low as possible.

[0047] <Column beam joint structure> Next, with reference to Figures 2 to 7, a column-beam connection structure according to an embodiment and the connection form between an S beam and a steel plate that constitutes the column-beam connection structure will be described. Here, Figure 2 is a longitudinal cross-sectional view of an example of a column-beam connection structure according to an embodiment, showing the bending moment borne by the S beam, the end of the SRC beam, and the steel plate in a hybrid beam, and Figure 3 is a perspective view of an example of the connection form between an S beam and a steel plate. Also, Figures 4 to 7 are perspective views of other examples of the connection form between an S beam and a steel plate. Note that the following description focuses on a form in which the side of the RC joint 50 and the end face of the S beam 10 abut (are continuous), but in addition to the illustrated example, a form in which the side of the RC joint 50 and the end face of the S beam 10 are separated may also be used.

[0048] The hybrid beam 30, which is a main girder, is erected between a pair of RC columns 40 and has an S beam 10 and an SRC beam end 20 at its end. The S beam 10 is formed from H-shaped steel and has a web 11, an upper flange 12, and a lower flange 13.

[0049] The SRC beam end 20 is formed by an RC structure 21 in which the S beam 10 is embedded within a predetermined section length t3 at the end of the S beam 10. The SRC beam end 20 is formed by arranging a plurality of upper end main reinforcements 22 above the S beam 10, a plurality of lower end main reinforcements 23 below the S beam 10, and a plurality of shear reinforcements 24 surrounding the upper end main reinforcements 22, lower end main reinforcements 23, and the S beam 10, and embedding these in the RC structure 21.

[0050] The multiple shear reinforcement bars 24 are arranged at a predetermined pitch in the longitudinal direction of the SRC beam end 20, but in the vicinity of both ends of the SRC beam end 20, there is a cross-sectional change area between the SRC beam end 20 and the S beam 10 or RC joint 50, and in view of the fact that this is an area where a large amount of shear force can act, the shear reinforcement bars 24 are arranged in a concentrated manner at a narrow pitch to reinforce the area.

[0051] Here, in the illustrated example, the upper end main reinforcement 22 and the lower end main reinforcement 23 do not extend into the interior of the RC joint 50, but if necessary, their ends may extend and be fixed into the interior of the RC joint 50, or they may be fixed into the interior of the RC joint with stud dowels or the like provided at their ends.

[0052] A plurality of column main reinforcements 41 extend continuously from top to bottom between the RC joint 50 and the upper and lower RC columns 40B, 40A, and shear reinforcement bars 42 surrounding the plurality of column main reinforcements 41 are arranged at a predetermined pitch in the longitudinal direction of the column.

[0053] A steel plate 60 is joined to the upper surface of the upper flange 12 of the H-shaped steel 10 that constitutes the SRC beam end 20 via a bolt 70, and an embedded portion 61, which is part of the steel plate 60, is embedded in the RC joint 50.

[0054] As shown in Figure 2, the hybrid beam 30, the floor of the upper floor supported by the hybrid beam 30, and the live load above it act as normal loads on the hybrid beam 30. For example, if normal load Q is assumed to act on the center of the span of the hybrid beam 30, an upper tensile bending moment with a triangular distribution as shown in the example will act on the left side region of the hybrid beam 30, and the bending moment M at the end of the SRC beam end 20 will be the largest bending moment.

[0055] As shown in the bending moment diagram, the steel beam 10 bears the entire bending moment (bending moment Ms) up to the boundary with the SRC beam end 20, and from the boundary with the SRC beam end 20 to the end, the bending moment Ms borne by the steel beam 10 decreases, but the bending moment Mrc borne by the RC structure 21 increases. The bending moment Mrc borne by the RC structure 21 determines the beam depth t4 of the SRC beam end 20, and if the bending moment Mrc is large, the beam depth t4 of the SRC beam end 20 becomes high, which may result in the SRC beam end 20 not fitting into the attic space.

[0056] Therefore, in the beam-column joint structure 100, a steel plate 60 is bolted to the upper flange 12 of the H-shaped steel 10 that constitutes the SRC beam end 20, and the embedded portion 61 of the steel plate 60 is embedded in the RC joint 50, so that the steel plate 60 bears part of the bending moment (bending moment Msp), thereby reducing the bending moment Mrc borne by the RC structure 21. This makes it possible to make the beam depth t4 of the SRC beam end 20, which is set by the bending moment Mrc, as low as possible, realizing a configuration in which the SRC beam end 20 can be securely placed in the attic space.

[0057] As shown in FIG. 3, the specific joining method between the upper flange 12 of the H-shaped steel 10 and the steel plate 60 is as follows: the steel plate 60 is placed on the upper surface of the upper flange 12, the bolt holes 12a in the upper flange 12 are aligned with the bolt holes 62 in the elongated steel plate 60, and bolts 70 are inserted into both bolt holes 12a, 62 and tightened with nuts.

[0058] The width t5 of the steel plate 60 is set to be shorter than the pitch of the column main reinforcements 41 in the RC joint 50 (and the RC columns 40A, 40B), and the overall dimensions are set to be such that they do not interfere with the shear reinforcement bars 42 and column main reinforcement bars 41 in the RC joint 50, etc. This makes it possible to smoothly insert the embedded portion 61 of the steel plate 60 into the gaps between the assembled column main reinforcement bars 41 and shear reinforcement bars 42.

[0059] In addition, by bolting the steel plate 60 to the upper surface of the upper flange 12, the height of the steel plate 60 that resists the generally dominant upper tensile bending moment can be increased by the thickness of the upper flange 12, and by increasing the bending moment Msp borne by the steel plate 60, the beam depth t4 of the SRC beam end 20 can be reduced.

[0060] Although not shown, if necessary, a steel plate may be bolted to, for example, the underside of the bottom flange 13. When the beam-column connection structure 100 is significantly displaced during an earthquake, a downward tensile bending moment may occur at the SRC beam end 20. If this downward tensile bending moment is larger than the normal upper tensile bending moment, a total downward tensile bending moment will occur at the SRC beam end. Therefore, if such an analysis result is obtained at the design stage, it is desirable to bolt the required amount of steel plate 60 to both the top flange 12 and the bottom flange 13.

[0061] In the beam-column joint structure 100, the steel plate 60 is bolted to the upper flange 12 of the H-shaped steel 10, eliminating the need for special skills such as a qualified welder, and anyone can carry out the construction (assembly).

[0062] Furthermore, by attaching the steel plates 60 on-site after the hybrid beam 30 is installed, when the SRC beam end 20 is installed in a predetermined position while the hybrid beam 30 is being hoisted by heavy machinery, the steel plates 60 do not become an obstacle to the hoisting and installation, which leads to reduced construction costs, improved workability, and a shorter construction period. For example, if reinforcing bars or the like are welded to the S beam or the like in advance, the reinforcing bars or the like become an obstacle when hoisting and installing the S beam.

[0063] After the hybrid beam 30 is installed to the RC joint 50 and the main column reinforcement 41 and shear reinforcement 42 of the RC column 40, a steel plate 60 is bolted to the upper flange 12 of the H-shaped steel 10 after installation, and concrete is poured into the RC joint 50 and the SRC beam end 20, thereby constructing the column-beam joint structure 100 on site.

[0064] Next, other examples of joining modes between an S beam and a steel plate will be described with reference to Figs.

[0065] 4 shows an example in which multiple stud dowels 63 are attached to the top and bottom surfaces of the embedded portion 61 of the steel plate 60. By embedding multiple stud dowels 63 in the RC joint 50, it is possible to improve the pull-out resistance of the steel plate 60 from the RC joint 50 (RC column) when a bending moment or shear force acts on the SRC beam end 20. Here, the stud dowels 63 may be attached to only one of the top surface or bottom surface of the upper flange 12, depending on the pull-out resistance required.

[0066] On the other hand, the example shown in FIG. 5 is a configuration in which two steel plates 60 equipped with a plurality of stud dowels 63 are bolted to the underside of the upper flange 12 of the H-shaped steel 10 .

[0067] According to this embodiment, multiple steel plates 60 are bolted to the underside of the upper flange 12, which prevents interference between the steel plates 60 and the upper main reinforcement 22 of the SRC beam end 20 above the upper flange 12. Here, when a steel plate 60 is bolted to the lower flange 13, the steel plate 60 is placed on the upper surface of the lower flange 13 and bolted to it, which prevents interference between the steel plate 60 and the lower main reinforcement 23 of the SRC beam end 20.

[0068] 6 uses a first unit 66 that is U-shaped in plan view and has two strips 65 extending from a base 64, and the base 64 is bolted to the upper flange 12 of the H-shaped steel 10. A plurality of stud dowels 63 are attached to the strips 65.

[0069] By applying the first unit 66, it becomes possible to further improve the attachability of a plurality of steel plates (strips 65) to the H-shaped steel 10. Although not shown in the figures, a unit having a base and three or more strips extending from the base, which has a comb-like shape in plan view, may also be applied.

[0070] 7 is a configuration in which a second unit 69 is applied, which includes a steel block 67 that is U-shaped in cross section and that laterally clamps the upper flange 12 of the H-shaped steel 10 and is bolted to the upper flange 12, and a steel plate 68 that protrudes from the steel block 67. A plurality of stud dowels 63 are attached to the steel plate 68.

[0071] Steel block 67, which is U-shaped in cross section, is bolted while sandwiching upper flange 12 from the sides, thereby increasing the fixing strength between second unit 69 and upper flange 12 compared to when a steel plate is bolted directly to upper flange 12. Note that the examples shown in Figures 6 and 7 are forms in which strips 65 or steel plate 68 corresponding to the steel plate are indirectly joined to upper flange 12, while the examples shown in Figures 3 to 5 are forms in which steel plate 60 is directly joined to upper flange 12.

[0072] The present invention is not limited to the configurations shown here, and other embodiments may be possible in which other components are combined with the configurations described in the above embodiments. In this regard, the present invention can be modified within the scope of the present invention, and can be appropriately determined depending on the application form. [Explanation of symbols]

[0073] 10:S beam (H section steel) 11:Web 12: Upper flange 12a: Bolt hole 13: Lower flange 20: SRC beam end 21:RC structure 22:Top main reinforcement 23: Bottom main reinforcement 24: Shear reinforcement 30: Hybrid beam 40,40A,40B:RC pillar 41:Column main reinforcement 42: Shear reinforcement 50:RC joint 60: Steel plate 61: Buried section 62: Bolt hole 63: Stud dowel 64: Base 65: Strip of paper 66: First Unit 67: Steel Block 68: Steel plate 69: Second Unit 70: Bolt 90:RC beam (RC beam) 95:RC small beam 100: Column beam joint structure 200: Hybrid structure SP1: Large space SP2: Narrow (general) space Q: Constant load M: Bending moment at the end of the SRC beam Ms: Bending moment borne by the steel beam Mrc: Bending moment borne by RC structure Msp: Bending moment borne by the steel plate

Claims

1. A column-beam joint structure consisting of a reinforced concrete column and an S beam formed by H-shaped steel, The end face of the S beam extends to the side face of the RC column or to the vicinity of the side face, A predetermined section of the end of the S beam is an SRC beam end made of steel reinforced concrete, in which an RC structure is integrally formed around the S beam, A steel plate is bolted directly or indirectly to at least the upper flange of the S beam, and a part of the steel plate is embedded in the RC column; A column-beam joint structure characterized in that a stud dowel is attached to the portion of the steel plate embedded in the RC column.

2. A column-beam joint structure consisting of a reinforced concrete column and an S beam formed by H-shaped steel, The end face of the S beam extends to the side face of the RC column or to the vicinity of the side face, A predetermined section of the end of the S beam is an SRC beam end made of steel reinforced concrete, in which an RC structure is integrally formed around the S beam, A steel plate is bolted directly or indirectly to at least the upper flange of the S beam, and a part of the steel plate is embedded in the RC column; A column-beam joint structure characterized in that a plurality of the steel plates are placed on the upper surface of the upper flange and bolted together.

3. A column-beam joint structure consisting of a reinforced concrete column and an S beam formed by H-shaped steel, The end face of the S beam extends to the side face of the RC column or to the vicinity of the side face, A predetermined section of the end of the S beam is an SRC beam end made of steel reinforced concrete, in which an RC structure is integrally formed around the S beam, A steel plate is bolted directly or indirectly to at least the upper flange of the S beam, and a part of the steel plate is embedded in the RC column; A column-beam joint structure characterized in that a plurality of the steel plates are placed on the underside of the upper flange and bolted together.

4. A column-beam joint structure consisting of a reinforced concrete column and an S beam formed by H-shaped steel, The end face of the S beam extends to the side face of the RC column or to the vicinity of the side face, A predetermined section of the end of the S beam is an SRC beam end made of steel reinforced concrete, in which an RC structure is integrally formed around the S beam, A steel plate is bolted directly or indirectly to at least the upper flange of the S beam, and a part of the steel plate is embedded in the RC column; A beam-column joint structure characterized in that the steel plate has a U-shape or a comb-tooth shape in plan view and is provided with a plurality of strips that are embedded in the RC column.

5. A column-beam joint structure consisting of a reinforced concrete column and an S beam formed by H-shaped steel, The end face of the S beam extends to the side face of the RC column or to the vicinity of the side face, A predetermined section of the end of the S beam is an SRC beam end made of steel reinforced concrete, in which an RC structure is integrally formed around the S beam, A steel plate is bolted directly or indirectly to at least the upper flange of the S beam, and a part of the steel plate is embedded in the RC column; A column-beam joint structure characterized by comprising a steel block having a U-shape in cross section, which clamps the upper flange from the side and is bolted to the upper flange, and a steel plate which extends from the steel block and is embedded in the RC column.

6. A column-beam joint structure as described in any one of claims 1 to 5, characterized in that a steel plate is bolted directly or indirectly to the lower flange of the S beam, and a portion of the steel plate is embedded in the RC column.

7. 7. The beam-column joint structure according to claim 1, wherein the steel plate has a width shorter than the pitch of the main column reinforcement of the RC column and has a dimension that does not interfere with the shear reinforcement and the main column reinforcement of the RC column.

8. 8. A beam-column joint structure according to claim 1, wherein the entire RC column, including the joint where the SRC beam end is joined, is a field-constructed RC column.

9. 8. A column-beam joint structure according to claim 1, wherein the joint to which the SRC beam end is joined is an on-site RC joint, and a PCa column made of precast concrete is joined to the RC joint.

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