Beam-column joint structure

Abstract

To provide a column-beam joint structure in which a plurality of steel beams are joined by penetrating a reinforced concrete column so that their positions in the height direction differ from each other, capable of increasing the strength of the column-beam joint with a relatively simple structure and excellent in economy, workability and structural performance. [Solution] A column-beam joint structure in which multiple steel beams are joined so as to penetrate a reinforced concrete column, wherein the multiple steel beams are joined to the reinforced concrete column so that they are at different height positions from each other, and a doubler plate is installed in the portion of the web of the steel beam that penetrates the reinforced concrete column.

Description

[Technical field]

[0001] The present invention relates to a column-beam joint structure between a reinforced concrete column and a steel beam. [Background technology]

[0002] The structural format of the building is the RCS structure, with columns made of reinforced concrete and beams made of steel. The RCS structure is a rational structure because it uses reinforced concrete members, which are strong against compression, for the columns and lightweight steel members, which are strong against bending and shear, for the beams. In other words, the steel beams allow for long spans, while the reinforced concrete columns economically increase the building rigidity and reliably support the building weight. Due to its characteristics, the RCS structure is particularly suitable for buildings with large spans and heavy loads, specifically logistics facilities and stores.

[0003] In RCS structures, the type of structure used for the column-beam joints is key to ensuring the structural performance of the entire building.The most commonly used column-beam joints in RCS structures are those in which the end of the steel beam penetrates from one side of the reinforced concrete column to the opposite side (hereafter referred to as the beam penetration type).

[0004] Here, when there is a step in the floor surface, such as in a logistics warehouse with a truck berth on the second floor or higher, or when the steel beams joined to the reinforced concrete columns have different beam depths, a step in the height direction will occur between two or more steel beams joined to the reinforced concrete column.

[0005] Patent Document 1 discloses a column-beam joint structure that can easily form a step between steel beams joined to a reinforced concrete column in an RCS structure. Specifically, a connecting member is provided to connect the upper steel beam and the lower steel beam at an embedded portion where the upper steel beam and the lower steel beam are embedded in a reinforced concrete column. The connecting member is joined to the flanges of the upper steel beam and the lower steel beam so that at least a part of the connecting member is located between the web of the upper steel beam and the web of the lower steel beam.

[0006] In addition, Non-Patent Documents 1 to 3 disclose the structure of column-beam joints in RCS structures when the top heights of two or more steel beams joined to a reinforced concrete column are different, or when the top heights of two or more steel beams are the same but the beam depths are different. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2018-162645 A [Non-patent literature]

[0008] [Non-Patent Document 1] Takayuki Sagawa et al., "Experimental and Analytical Study on the Structural Performance of a Frame Composed of Reinforced Concrete Columns and Steel Beams with Step Beams, Proceedings of the Japan Concrete Institute, Vol. 37, No. 2, February 2015, pp. 1045-1050 [Non-Patent Document 2] Naoki Arakane and 3 others, "Structural Performance of RC-Column / S-Beam Mixed Structure: Part 4-6", Proceedings of the Annual Meeting of the Architectural Institute of Japan, Architectural Institute of Japan, July 2013, pp.1467-1472 [Non-Patent Document 3] Masatoshi Harada et al., "Structural Performance of Cross-Shaped Beam-Column Joints in RC-Column / S-Beam Mixed Structures with Beam Eccentricity and Beam Steps, Part 1-2," Abstracts of Academic Lectures at the Architectural Institute of Japan Annual Meeting, Architectural Institute of Japan, July 2018, pp.1457-1460 Summary of the Invention [Problem to be solved by the invention]

[0009] In the above-mentioned beam-through type column-beam joint structure, if one tries to increase the strength, the following problems arise.

[0010] First, if one tries to increase the strength of the concrete only within the beam-column joint as a method of increasing the bearing capacity of the joint, it would require pouring concrete of different strengths for the beam-column joint and the rest of the reinforced concrete column, which is undesirable in terms of workability and structural performance.

[0011] In addition, if an attempt is made to increase the frame effect of constraining the concrete in the column-beam joint by increasing the thickness of the cover plate that surrounds the concrete in the column-beam joint, the bending radius when bending the corner of the cover plate becomes large, which tends to affect the position of the main reinforcement of the reinforced concrete column. In order to avoid this, if the corner of the cover plate is formed by welding two steel plates together, the processing work for the cover plate will increase.

[0012] Additionally, increasing the thickness of the steel beam web to increase the shear strength of the steel beam web in the beam-column joint panel increases the cost of the steel beam.

[0013] Furthermore, if one tries to increase the strength of a column-beam joint by enlarging its cross-section, it becomes necessary to match the cross-section of the reinforced concrete column to the enlarged cross-section of the column-beam joint, which means that the cross-section of the reinforced concrete column also becomes larger.

[0014] The present invention has been made to solve the above-mentioned problems, and aims to provide a column-beam joint structure in which multiple steel beams are joined by penetrating a reinforced concrete column so that they are at different height positions from each other, which can increase the strength of the column-beam joint with a relatively simple structure and is excellent in terms of economy, ease of construction, and structural performance. [Means for solving the problem]

[0015] The means for solving the above problems are as follows. [1] A column-beam joint structure in which multiple steel beams are joined to a reinforced concrete column so that they penetrate into the column, the multiple steel beams are joined to the reinforced concrete column so that their vertical positions are different from each other, and a doubler plate is installed in the portion of the web of the steel beam that penetrates into the reinforced concrete column.

[0016] Here, "the height positions of the multiple steel beams are different from each other" means that the heights of the upper or lower ends of the multiple steel beams, or the beam depths of the multiple steel beams, are different from each other. [2] A column-beam joint structure as described in [1], wherein at least two of the plurality of steel beams are arranged within the same structural plane, the lower end of the upper steel beam which is the steel beam with the higher beam depth center of the two steel beams is lower than the upper end of the lower steel beam which is the steel beam with the lower beam depth center, and the doubler plate is arranged at a height between the lower end of the upper steel beam and the upper end of the lower steel beam. [3] A column-beam joint structure described in [1], in which the end of a brace is further connected to the column-beam joint between the reinforced concrete column and the steel beam. [4] A column-beam joint structure described in [2], in which the end of a brace is further connected to the column-beam joint between the reinforced concrete column and the steel beam. [5] The structure of a column-beam joint described in [1], wherein at least two of the plurality of steel beams are arranged within the same structural plane, the lower end of the upper steel beam which is the steel beam with the higher beam center of the two steel beams is higher than the upper end of the lower steel beam which is the steel beam with the lower beam center of the two steel beams, the lower flange of the upper steel beam and the upper flange of the lower steel beam are joined by a connecting plate, the end of a brace is further joined to the column-beam joint between the reinforced concrete column and the two steel beams, and the doubler plate is arranged in the part of the web of the steel beam which is arranged in the same span as the brace and penetrates the reinforced concrete column. [6] A column-beam joint structure described in [5], in which the doubler plate is not arranged in the portion of the web of the steel beam that is not arranged in the same span as the brace, which penetrates the reinforced concrete column. [7] A structure of a beam-column joint described in any of [1] to [6], in which holes for filling with concrete are provided in the portion of the web of the steel beam that penetrates the reinforced concrete column and in the doubler plate. Effect of the Invention

[0017] According to the column-beam joint structure of the present invention, in a column-beam joint structure in which multiple steel beams are joined so as to penetrate a reinforced concrete column, a doubler plate is installed in the portion of the web of the steel beam that penetrates the reinforced concrete column. Therefore, it is possible to increase the bearing strength of the column-beam joint with a relatively simple structure, and it is possible to realize a column-beam joint that is excellent in economy, workability, and structural performance while facilitating the design of the column-beam joint between the reinforced concrete column and the steel beam.

[0018] In addition, because a doubler plate is installed on the portion of the web of the steel beam that penetrates the reinforced concrete column, it is possible to open large holes for filling concrete in the web of the steel beam and the doubler plate, which improves the filling of concrete in the column-beam joint and makes pouring the concrete easier. [Brief description of the drawings]

[0019] [Figure 1] Fig. 1(a) and Fig. 1(b) are a vertical cross-sectional view and a perspective view, respectively, showing a structure of a beam-column joint according to a first embodiment of the present invention, and Fig. 1(c) is a perspective view showing a main part of the structure of the beam-column joint shown in Fig. 1(a) and Fig. 1(b). [Diagram 2] FIG. 2 is a vertical cross-sectional view showing the structure of a beam-column joint according to a modified example of the first embodiment of the present invention. [Diagram 3] FIG. 3(a) and FIG. 3(b) are a vertical sectional view and a perspective view, respectively, showing the structure of a beam-column joint according to a second embodiment of the present invention. [Figure 4] FIG. 4 is a vertical cross-sectional view showing the structure of a beam-column joint according to a modified example of the second embodiment of the present invention. [Diagram 5] Fig. 5(a) and Fig. 5(b) are a vertical cross-sectional view and a perspective view, respectively, showing a structure of a beam-column joint according to a third embodiment of the present invention, and Fig. 5(c) is a perspective view showing a main part of the structure of the beam-column joint shown in Fig. 5(a) and Fig. 5(b). [Figure 6] FIG. 6(a) and FIG. 6(b) are a vertical sectional view and a perspective view, respectively, showing a structure of a beam-column joint according to a fourth embodiment of the present invention. [Figure 7] 7(a) and 7(b) are a vertical sectional view and a perspective view, respectively, showing the structure of a beam-column joint according to a fifth embodiment of the present invention. [Figure 8] Fig. 8(a) and Fig. 8(b) are vertical cross-sectional views showing a beam-column joint according to a sixth embodiment of the present invention, and Fig. 8(c) is a perspective view of the beam-column joint shown in Fig. 8(a) and Fig. 8(b). [Figure 9] 9(a) and 9(b) are side views showing a state in which an end of a brace is joined to a column-beam joint in a column-beam joint structure according to a modified example of the first embodiment of the present invention. [Figure 10] FIG. 10 is a side view showing a state in which an end of a brace is joined to a column-beam joint in a column-beam joint structure according to a modified example of the second embodiment of the present invention. [Figure 11] 11(a) and 11(b) are side views showing a state in which an end of a brace is joined to a column-beam joint in a column-beam joint structure according to a modified example of the third embodiment of the present invention. [Figure 12] 12(a) and 12(b) are side views showing a state in which an end of a brace is joined to a column-beam joint in a column-beam joint structure according to a modified example of the fourth embodiment of the present invention. [Figure 13] FIG. 13 is a side view showing a state in which an end of a brace is joined to a column-beam joint in a column-beam joint structure according to the fifth embodiment of the present invention. [Figure 14] FIG. 14 is a graph showing the relationship between the effective section modulus cpk of concrete and the ratio of column depth to beam depth CD / BD in the beam-column joint structure of the present invention. [Figure 15] FIG. 15 is a graph showing the relationship between the effective section modulus cpk of concrete and the ratio Cb / Bb of the column width to the beam width in a column-beam joint structure of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, an embodiment of the column-beam joint structure of the present invention will be specifically described with reference to the drawings. First Embodiment 1(a) and 1(b) show a longitudinal sectional view and a perspective view of a column-beam joint 1A according to a first embodiment of the present invention, and FIG. 1(c) shows a perspective view of a main part of the column-beam joint 1A according to the first embodiment of the present invention.

[0021] As shown in Figures 1(a) to 1(c), in the structure of a beam-column joint 1A of the first embodiment, four steel beams 3A, 3C, 3D, and 4 made of H-shaped steel are connected to a reinforced concrete column 2 so as to penetrate the column. The structure of the beam-column joint 1A of the first embodiment is applied to a beam-penetration type cover plate type beam-column joint in which four steel beams 3A, 3C, 3D, and 4 are attached in a cross shape to the four sides of the reinforced concrete column 2. As shown in Figures 1(a) and 1(b), the steel beams 3A, 3C, 3D, and 4 intersecting in a cross shape are each provided so as to completely penetrate the reinforced concrete column 2 from one side to the opposite side.

[0022] In addition, when the steel beams are attached in a T-shape to three sides of the reinforced concrete column 2, or when the steel beams are attached in an L-shape to two sides of the reinforced concrete column 2, the steel beams that intersect in a T-shape or L-shape are installed so that they completely penetrate from one side of the reinforced concrete column 2 to the opposite side.

[0023] The four steel beams 3A, 3C, 3D, 4 are joined to the reinforced concrete column 2 so that their height positions are different from each other. Specifically, in the main direction, two steel beams 3A, 4 are arranged in the same structural plane and joined to the reinforced concrete column 2. In the perpendicular direction, two steel beams 3C, 3D are arranged in the same structural plane and joined to the reinforced concrete column 2. The beam depths of the four steel beams 3A, 3C, 3D, 4 are equal to each other, but the heights of the upper ends of the steel beams 3A, 3C, 3D and the upper end of the steel beam 4 are different, and the lower ends of the upper three steel beams 3A, 3C, 3D are lower than the upper end of the lower steel beam 4. In other words, the beam depth of the steel beam 3A in the main direction among the upper steel beams 3A, 3C, 3D is: B D1(mm), beam depth of lower steel beam 4: B D2 (mm), center distance between upper steel beam 3A and lower steel beam 4: B If H (mm), the step ratio of steel beams 3A and 4 is 2 B H / ( B D1+ B D2)<1.

[0024] As shown in Figures 1(b) and 1(c), the two steel beams 3C, 3D joined to both sides of the reinforced concrete column 2 in the orthogonal direction are actually composed of a single H-shaped steel arranged to penetrate the reinforced concrete column 2. Among the steel beams 3A, 4 arranged in the main direction, the upper steel beam 3A is arranged to penetrate the H-shaped steel constituting the two steel beams 3C, 3D in the orthogonal direction, and is welded to both sides of this H-shaped steel.

[0025] 1(a) and 1(c), on both sides of the portion where the lower steel beam 4 of the steel beams 3A, 4 arranged in the main direction penetrates the reinforced concrete column 2, anchoring parts 44 for holding cover plates 22 (described later) are arranged so as to penetrate the H-shaped steel constituting the lower steel beam 4 and are welded to both sides of this H-shaped steel. The anchoring parts 44 are made of T-shaped steel with a beam depth equal to the difference in height between the bottom end of the upper steel beam 3A and the bottom end of the lower steel beam 4.

[0026] In the structure of the beam-column joint 1A of the first embodiment, as shown in Fig. 1(a) and Fig. 1(c), within the beam-column joint 1A, the webs 31, 41 of the steel beams 3A, 4 in the main direction are reinforced by a doubler plate 7. Specifically, the entire length of the outer periphery of the doubler plate 7 is fixed to the webs 31, 41 of the steel beams 3A, 4 by fillet welding or the like. Although not shown in the figures, in the beam-column joint 1A, the webs 31 of the steel beams 3C, 3D in the orthogonal direction are also reinforced by the doubler plate 7 in the same manner.

[0027] In this way, in the structure of the beam-column joint 1A of the first embodiment, a doubler plate 7 is installed and reinforced on the webs 31, 41 of the steel beams 3A, 3C, 3D, 4 within the beam-column joint 1A, so that the shear strength of the doubler plate 7 can be added to the shear strength of the entire beam-column joint 1A.

[0028] In the structure of the beam-column joint 1A of the first embodiment, as shown in Fig. 1(a) and Fig. 1(c), holes 31h, 41h, 7h for filling concrete are provided in the portions of the webs 31, 41 of the steel beams 3A, 4 in the main direction that penetrate into the reinforced concrete column 2 and in the doubler plate 7 fixed to this portion. Although not shown in the figures, holes for filling concrete are also provided in the portions of the webs 31 of the steel beams 3C, 3D in the orthogonal direction that penetrate into the reinforced concrete column 2 and in the doubler plate fixed to this portion.

[0029] In the structure of the beam-column joint 1A of the first embodiment, the webs 31, 41 of the steel beams 3A, 3C, 3D, 4 in the beam-column joint 1A between the reinforced concrete column 2 and the steel beams 3A, 3C, 3D, 4 are reinforced by the doubler plate 7, so it is possible to open large holes 31h, 41h, 7h for filling concrete in the webs 31, 41 of the steel beams 3A, 3C, 3D, 4 in the beam-column joint 1A and the doubler plate 7. This improves the filling property of concrete in the beam-column joint 1A, making it easier to pour the concrete.

[0030] In the structure of the beam-column joint 1A of the first embodiment, as shown in Fig. 1(a) to Fig. 1(c), a cover plate 22 made of a steel plate is provided so as to surround the concrete (not shown) poured continuously into the beam-column joint 1A from the reinforced concrete columns 2 above and below the beam-column joint 1A. The cover plate 22 is provided so as to completely cover the concrete in the beam-column joint 1 up to the surface position of the webs 31, 41 of the steel beams 3A, 3C, 3D, 4 within the height range between the upper flanges 32, 42 and the lower flanges 33, 43 of the steel beams 3A, 3C, 3D, 4. The side edges of the cover plate 22 are fixed by welding to the webs 31, 41, the upper flanges 32, 42, and the lower flanges 33, 43 of the steel beams 3A, 3C, 3D, 4, as well as to the web and lower flange of the T-shaped steel constituting the anchoring portion 44 of the steel beam 4. As described above, even at the locations where the steel beams 3A, 3C, 3D, 4 that penetrate the reinforced concrete column 2 protrude onto the opposite side of the reinforced concrete column 2, the cover plates 22 are fixed by welding to the webs 31, 41, upper flanges 32, 42, and lower flanges 33, 43 of the steel beams 3A, 3C, 3D, 4.

[0031] Width of cover plate 22 h b(mm) and thickness h t(mm) is h b / h t ≤ 217 and h It is preferable to satisfy the relationship t ≧ 6. This makes it possible to suppress buckling of the cover plate 22 and obtain a sufficient frame effect of restraining the concrete by the cover plate 22, thereby increasing the strength of the beam-column joint 1A.

[0032] Here, the width of the blocking plate 22 hb (mm) refers to the total horizontal width of each of the cover plates 22 provided between horizontally adjacent steel beams 3A, 4 among the multiple steel beams 3A, 4 attached to the reinforced concrete column 2, and corresponds to the total width of the beam-column joint 1A as shown in FIG. 1(b). For example, in the structure of the beam-column joint 1A shown in FIG. 1(a) to FIG. 1(c), four cover plates 22 bent into an L-shape are provided to cover the concrete (not shown) between the adjacent steel beams 3A, 4. h b (mm) refers to the overall width of each of these blocking plates 22 before bending.

[0033] Alternatively, in the structure of the beam-column joint 1A shown in Fig. 1(a) to Fig. 1(c), a bearing plate (not shown) for bearing the concrete in the beam-column joint 1A may be provided in the area surrounded by the web 31, upper flange 32, and lower flange 33 of the steel beams 3A, 3C, and 3D, and the area surrounded by the web 41, upper flange 42, and lower flange 43 of the steel beam 4. For the bearing plate, a steel plate having a thickness equal to or greater than the thickness of the webs 31 and 41 of the steel beams 3A and 4 is preferably used, and the bearing plate is fixed by welding to the web 31, upper flange 32, and lower flange 33 of the steel beams 3A, 3C, and 3D, or the web 41, upper flange 42, and lower flange 43 of the steel beam 4. Then, a cover plate 22 is provided to surround the part of the concrete (not shown) poured continuously from the reinforced concrete columns 2 above and below the beam-column joint 1A in the beam-column joint 1A that is not covered by the bearing plate and remains. The bearing plates and cover plates 22 are installed so as to completely cover the concrete in the beam-column joint 1A up to the surface positions of the webs 31 of the steel beams 3A, 3C, 3D and the web 41 of the steel beam 4, within the height range between the upper flanges 32 of the steel beams 3A, 3C, 3D and the lower flange 43 of the steel beam 4. The cover plates 22 are installed so as to be continuous with the bearing plates, and are fixed to the bearing plates by welding or bolting.

[0034] In this way, the bearing plate enhances the bearing effect of the concrete, allowing the concrete in the beam-column joint 1A to fully exert its shear strength. In addition, the frame effect of the bearing plate increases the shear strength borne by the webs 31, 41 and doubler plate 7 of the steel beams 3A, 3C, 3D, 4 in the beam-column joint 1A.

[0035] According to the structure of the beam-column joint 1A of the first embodiment, the webs 31, 41 of the steel beams 3A, 3C, 3D, 4 in the beam-column joint 1A between the reinforced concrete column 2 and the steel beams 3A, 3C, 3D, 4 are reinforced by the doubler plate 7, so that the strength of the beam-column joint 1A can be increased with a relatively simple structure. In addition, in the structure of the beam-column joint 1A of the first embodiment, the shear strength of the doubler plate 7 can be added to the shear strength of the entire beam-column joint 1A, so that the design of the beam-column joint 1A can be made easier. In this way, the structure of the beam-column joint 1A of the first embodiment can realize a beam-column joint 1A that is excellent in economy, workability, and structural performance while making it easy to design the beam-column joint 1A between the reinforced concrete column 2 and the steel beams 3A, 3C, 3D, 4.

[0036] Unlike a method of increasing the bearing capacity of a column-beam joint by increasing the strength of the concrete only in the column-beam joint, the structure of column-beam joint 1A in the first embodiment allows concrete with the same strength to be poured integrally in column-beam joint 1A and the rest of reinforced concrete column 2. Therefore, the structure of column-beam joint 1A in the first embodiment is excellent in terms of workability and structural performance.

[0037] In addition, by reinforcing the webs 31, 41 of the steel beams 3A, 3C, 3D, 4 in the beam-column joint 1A with the doubler plate 7, the bearing strength of the beam-column joint 1A can be increased without increasing the thickness of the cover plate 22. This eliminates the need to increase the bending radius according to the plate thickness when bending the corners of the cover plate, and does not affect the position of the main reinforcement 21 of the reinforced concrete column 2.

[0038] Furthermore, in the structure of the beam-column joint 1A of the first embodiment, the thickness of the webs 31, 41 of the steel beams 3A, 3C, 3D, 4 as a whole is not increased, but the webs 31, 41 of the steel beams 3A, 3C, 3D, 4 are reinforced by the doubler plate 7 only within the beam-column joint 1A. Therefore, the cost required for the steel beams 3A, 4 does not increase.

[0039] FIG. 2 shows a vertical cross-sectional view of a structure of a beam-column joint 1A′ according to a modified example of the first embodiment of the present invention, together with the distribution of shear force generated in the reinforced concrete column 2 in the horizontal direction.

[0040] As shown in the shear force distribution on the right side of FIG. 2, in the structure of the beam-column joint 1A of the first embodiment, a large shear force is generated in the region where the webs 31, 41 of the two steel beams 3A, 4 arranged in the main direction overlap in the height direction, that is, in the height range between the lower end of the upper steel beam 3A and the upper end of the lower steel beam 4. Therefore, in the structure of the beam-column joint 1A' of the modified first embodiment, the doubler plate 7 is provided only in the area where the stress is concentrated. That is, in the structure of the beam-column joint 1A' of the modified first embodiment, as shown in FIG. 2, the doubler plate 7 is arranged only in the height range between the lower end of the upper steel beam 3A and the upper end of the lower steel beam 4. In other respects, the structure of the beam-column joint 1A' of the modified first embodiment is configured similarly to the structure of the beam-column joint 1A of the first embodiment.

[0041] In the structure of the beam-column joint 1A' according to the modification of the first embodiment, the doubler plate 7 is provided only at locations where stress is concentrated, resulting in a more rational structure and making it easier to design the beam-column joint.

[0042] The structure of the beam-column joint 1A of the first embodiment and the structure of the beam-column joint 1A' of the modified example of the first embodiment are the beam depth ratios of the steel beams 3A and 4 in the main direction. B D2 / B D1( B D1≧ BIt is preferable to apply this when D2) is within the range of 0.5 to 1.0. In addition, the beam depth of the steel beams 3C and 3D in the orthogonal direction among the steel beams 3A, 3C, and 3D in the upper stage: B If D3 (mm), the beam depth ratio of steel beam 3A in the main direction and steel beam 3C and 3D in the perpendicular direction is B D3 / B It is preferable to apply this when D1 is within the range of 0.5 to 1.0. Second Embodiment FIG. 3(a) and FIG. 3(b) show a vertical cross-sectional view and a perspective view of a structure of a beam-column joint 1B according to a second embodiment of the present invention.

[0043] As shown in Fig. 3(a) and Fig. 3(b), in the structure of the beam-column joint 1B of the second embodiment, four steel beams 3B-3D, 5A made of H-shaped steel are joined to the reinforced concrete column 2 so as to penetrate the column. The four steel beams 3B-3D, 5A are joined to the reinforced concrete column 2 so that their height positions are different from each other. Specifically, in the main direction, two steel beams 3B, 5A are arranged in the same structural plane and joined to the reinforced concrete column 2, and in the perpendicular direction, two steel beams 3C, 3D are arranged in the same structural plane and joined to the reinforced concrete column 2. The heights of the upper ends of the four steel beams 3B-3D, 5A are equal to each other, but the beam depth of the steel beam 5A is smaller than the beam depth of the steel beams 3B-3D, and the height of the lower ends of the steel beams 3B-3D is lower than the height of the lower end of the steel beam 5A. That is, the beam depth of the steel beam 3B in the main direction: B D1(mm), beam depth of steel beam 5A: B If D2 (mm), then B D1> B It's D2.

[0044] As shown in Fig. 3(b), the two steel beams 3C, 3D joined to both sides of the reinforced concrete column 2 in the orthogonal direction are actually composed of a single H-shaped steel arranged to penetrate the reinforced concrete column 2. The steel beams 3B, 5A arranged in the main direction are welded to both sides of the H-shaped steel constituting the two orthogonal steel beams 3C, 3D.

[0045] In the structure of the beam-column joint 1B of the second embodiment, as shown in Fig. 3(a), in the beam-column joint 1B, the webs 31, 51 of the steel beams 3B, 5A in the main direction are reinforced by a doubler plate 7. Specifically, the entire circumference of the doubler plate 7 is fixed to the webs 31, 51 of the steel beams 3B, 5A by fillet welding or the like. Although not shown in the figure, in the beam-column joint 1B, the webs 31 of the steel beams 3C, 3D in the orthogonal direction are also reinforced by a doubler plate in the same manner.

[0046] In this way, in the structure of the column-beam joint 1B of the second embodiment, a doubler plate 7 is installed and reinforced on the webs 31, 51 of the steel beams 3B to 3D, 5A within the column-beam joint 1B, so that the shear strength of the doubler plate 7 can be added to the shear strength of the entire column-beam joint 1B.

[0047] In the structure of the beam-column joint 1B of the second embodiment, as shown in Fig. 3(a), holes 31h, 51h, 7h for filling concrete are provided in the portions of the webs 31, 51 of the steel beams 3B, 5A in the main direction that penetrate into the reinforced concrete column 2 and in the doubler plate 7 fixed to these portions. Although not shown in the figure, holes for filling concrete are also provided in the portions of the webs 31 of the steel beams 3C, 3D in the orthogonal direction that penetrate into the reinforced concrete column 2 and in the doubler plate fixed to these portions.

[0048] In the structure of the beam-column joint 1B of the second embodiment, the webs 31, 51 of the steel beams 3B-3D, 5A in the beam-column joint 1B between the reinforced concrete column 2 and the steel beams 3B-3D, 5A are reinforced by the doubler plate 7, so that it is possible to open large holes 31h, 51h, 7h for filling concrete in the webs 31, 51 of the steel beams 3B-3D, 5A in the beam-column joint 1B and the doubler plate 7. This improves the filling property of concrete in the beam-column joint 1B, making it easier to pour the concrete.

[0049] In other respects, the structure of the beam-column joint 1B of the second embodiment is configured similarly to the structure of the beam-column joint 1A of the first embodiment.

[0050] According to the structure of the beam-column joint 1B of the second embodiment, the same effects as those of the structure of the beam-column joint 1A of the first embodiment can be obtained.

[0051] FIG. 4 shows a vertical cross-sectional view of a structure of a beam-column joint 1B′ according to a modified example of the second embodiment of the present invention, together with the distribution of shear force generated in the reinforced concrete column 2 in the horizontal direction.

[0052] As shown in the shear force distribution on the right side of FIG. 4, in the structure of the beam-column joint 1B of the second embodiment, a large shear force is generated in the region where the webs 31, 51 of the two steel beams 3B, 5A arranged in the main direction overlap in the height direction, that is, in the range of height between the upper end and the lower end of the steel beam 5A. Therefore, in the structure of the beam-column joint 1B' of the modified example of the second embodiment, the doubler plate 7 is provided only in the area where the stress is concentrated. That is, in the structure of the beam-column joint 1B' of the modified example of the second embodiment, as shown in FIG. 4, the doubler plate 7 is arranged only in the range of height between the upper end and the lower end of the steel beam 5A. In other respects, the structure of the beam-column joint 1B' of the modified example of the second embodiment is configured similarly to the structure of the beam-column joint 1B of the second embodiment.

[0053] In the structure of beam-column joint 1B' according to the modified example of the second embodiment, the doubler plate 7 is provided only at locations where stress is concentrated, resulting in a more rational structure and making it easier to design the beam-column joint. Third embodiment 5(a) and 5(b) show a longitudinal section and a perspective view of the structure of a beam-column joint 1C according to the third embodiment of the present invention. Also, FIG. 5(c) shows a perspective view of the main part of the structure of the beam-column joint 1C according to the third embodiment of the present invention. FIG. 5(a) also shows the distribution of shear force generated in the horizontal direction in the reinforced concrete column 2.

[0054] As shown in Fig. 5(a) and Fig. 5(b), in the structure of the beam-column joint 1C of the third embodiment, four steel beams 3A, 3C, 3D, and 4 made of H-shaped steel are joined to the reinforced concrete column 2 so as to penetrate the column. The four steel beams 3A, 3C, 3D, and 4 are joined to the reinforced concrete column 2 so that their height positions are different from each other. Specifically, in the main direction, two steel beams 3A and 4 are arranged in the same structural plane and joined to the reinforced concrete column 2, and in the orthogonal direction, two steel beams 3C and 3D are arranged in the same structural plane and joined to the reinforced concrete column 2. The beam depths of the four steel beams 3A, 3C, 3D, and 4 are equal to each other, but the heights of the upper ends of the steel beams 3A, 3C, and 3D are different from the height of the upper end of the steel beam 4, and the lower ends of the upper three steel beams 3A, 3C, and 3D are higher than the upper end of the steel beam 4 in the lower stage. That is, the beam depth of the steel beam 3A in the main direction among the upper steel beams 3A, 3C, and 3D is: B D1(mm), beam depth of lower steel beam 4: B D2 (mm), center distance between upper steel beam 3A and lower steel beam 4: B If H (mm), the step ratio of steel beams 3A and 4 is 2 B H / ( B D1+ B D2)>1.

[0055] A bottom flange 33 of one steel beam 3A of the three upper steel beams 3A, 3C, 3D and a top flange 42 of the lower steel beam 4 are joined by a tie plate 6. The tie plate 6 is disposed in the same plane as the webs 31, 41 of the upper steel beam 3A and the lower steel beam 4 joined by the tie plate 6.

[0056] As shown in Figures 5(b) and 5(c), the two steel beams 3C, 3D joined to both sides of the reinforced concrete column 2 in the orthogonal direction are actually composed of a single H-shaped steel arranged to penetrate the reinforced concrete column 2. Among the steel beams 3A, 4 arranged in the main direction, the upper steel beam 3A is arranged to penetrate the H-shaped steel constituting the two steel beams 3C, 3D in the orthogonal direction, and is welded to both sides of this H-shaped steel.

[0057] 5(a) and 5(c), on both sides of the portion where the lower steel beam 4 of the steel beams 3A, 4 arranged in the main direction penetrates the reinforced concrete column 2, anchoring parts 44 for holding the cover plates 22 are arranged so as to penetrate the H-shaped steel constituting the lower steel beam 4, and are welded to both sides of this H-shaped steel and to connecting plates 6 (described later) arranged in the same plane as the webs of the steel beams 3C, 3D. The anchoring parts 44 are composed of H-shaped steel having the same beam depth as the steel beam 4.

[0058] The bottom flanges 33 of two of the three steel beams 3A, 3C, 3D in the upper stage, which are arranged in an orthogonal direction, are joined to the top flanges of the H-shaped steel that constitutes the anchoring portion 44 by a tie plate 6. The tie plate 6 is arranged in the same plane as the webs 31 of the steel beams 3C, 3D that are joined by this tie plate 6 and the web of the steel beam that constitutes the anchoring portion 44.

[0059] In the structure of a beam-column joint 1C of the third embodiment, as shown in Fig. 5(a) and Fig. 5(c), in the beam-column joint 1C, the webs 31, 41 of the steel beams 3A, 4 in the main direction are reinforced by a doubler plate 7. Specifically, the entire circumference of the doubler plate 7 is fixed to the webs 31, 41 of the steel beams 3A, 4 by fillet welding or the like. Although not shown in the figures, in the beam-column joint 1C, the webs 31 of the steel beams 3C, 3D in the orthogonal direction are also reinforced by a doubler plate in the same manner.

[0060] In this way, in the structure of the beam-column joint 1C of the third embodiment, a doubler plate 7 is installed and reinforced on the webs 31, 41 of the steel beams 3A, 3C, 3D, 4 within the beam-column joint 1C, so that the shear strength of the doubler plate 7 can be added to the shear strength of the entire beam-column joint 1C.

[0061] In the structure of the beam-column joint 1C of the third embodiment, as shown in Fig. 5(a), holes 31h, 41h, 7h for filling concrete are provided in the portions of the webs 31, 41 of the steel beams 3A, 4 in the main direction that penetrate into the reinforced concrete column 2 and in the doubler plate 7 fixed to this portion. Although not shown in the figure, holes for filling concrete are also provided in the portions of the webs 31 of the steel beams 3C, 3D in the orthogonal direction that penetrate into the reinforced concrete column 2 and in the doubler plate fixed to this portion.

[0062] In the structure of the beam-column joint 1C of the third embodiment, the webs 31, 41 of the steel beams 3A, 3C, 3D, 4 in the beam-column joint 1C between the reinforced concrete column 2 and the steel beams 3A, 3C, 3D, 4 are reinforced by the doubler plate 7, so it is possible to open large holes 31h, 41h, 7h for filling concrete in the webs 31, 41 of the steel beams 3A, 3C, 3D, 4 in the beam-column joint 1C and the doubler plate 7. This improves the filling property of concrete in the beam-column joint 1C, making it easier to pour the concrete.

[0063] In addition, in the structure of the beam-column joint 1C of the third embodiment, as shown in FIG. 5(a), the connecting plate 6 that connects the steel beam 3A in the main direction of the upper three steel beams 3A, 3C, and 3D to the steel beam 4 in the lower stage is also provided with a hole 6h for filling concrete. As shown in the shear force distribution shown on the right side of FIG. 5(a), in the structure of the beam-column joint 1C of the third embodiment, the shear force acting on the connecting plate 6 is smaller than the shear force acting on the webs 31 and 41 of the steel beams 3A and 4. Therefore, the hole diameter of the hole 6h provided in the connecting plate 6 can be made larger than the hole diameter of the holes 31h and 41h provided in the webs 31 and 41 of the steel beams 3A and 4. This further improves the filling property of concrete in the beam-column joint 1C, making it easier to pour concrete.

[0064] In other respects, the structure of the beam-column joint 1C of the third embodiment is configured similarly to the structure of the beam-column joint 1A of the first embodiment.

[0065] The structure of the column-beam joint 1C of the third embodiment is a step ratio of 2 for the steel beams 3A, 3C, 3D, and 4. B H / ( B D1+ B It is preferable to apply when D2)≦1.25.

[0066] According to the structure of the beam-column joint 1C of the third embodiment, the same effects as those of the structure of the beam-column joint 1A of the first embodiment can be obtained. (Fourth embodiment) FIG. 6(a) and FIG. 6(b) show a vertical cross-sectional view and a perspective view of a structure of a beam-column joint 1D according to a fourth embodiment of the present invention.

[0067] As shown in Fig. 6(a) and Fig. 6(b), in the structure of the beam-column joint 1D of the fourth embodiment, four steel beams 3A, 3C, 3D, 4 made of H-shaped steel are joined to the reinforced concrete column 2 so as to penetrate the column. The four steel beams 3A, 3C, 3D, 4 are joined to the reinforced concrete column 2 so that their height positions are different from each other. Specifically, in the main direction, two steel beams 3A, 4 are arranged in the same structural plane and joined to the reinforced concrete column 2, and in the orthogonal direction, two steel beams 3C, 3D are arranged in the same structural plane and joined to the reinforced concrete column 2. The beam depths of the four steel beams 3A, 3C, 3D, 4 are equal to each other, but the height of the upper end of the steel beams 3A, 3C, 3D is different from the height of the upper end of the steel beam 4, and the bottom flanges 33 of the upper three steel beams 3A, 3C, 3D are at the same height as the top flanges 42 of the lower steel beam 4. That is, the beam depth of the steel beam 3A in the main direction among the upper steel beams 3A, 3C, and 3D is: B D1(mm), beam depth of lower steel beam 4: B D2 (mm), center distance between upper steel beam 3A and lower steel beam 4: B If H (mm), the step ratio of steel beams 3A and 4 is 2 B H / ( B D1+ B D2)=1.

[0068] As shown in Fig. 6(b), the two steel beams 3C, 3D joined to both sides of the reinforced concrete column 2 in the orthogonal direction are actually composed of a single H-shaped steel arranged to penetrate the reinforced concrete column 2. Among the steel beams 3A, 4 arranged in the main direction, the upper steel beam 3A is arranged to penetrate the H-shaped steel constituting the two steel beams 3C, 3D in the orthogonal direction, and is welded to both sides of this H-shaped steel.

[0069] Furthermore, on both sides of the portion where the lower steel beam 4 of the steel beams 3A, 4 arranged in the main direction penetrates the reinforced concrete column 2, anchoring parts 44 for holding the cover plates 22 are arranged so as to penetrate the H-shaped steel constituting the lower steel beam 4 and are welded to both sides of this H-shaped steel. The anchoring parts 44 are made of T-shaped steel having the same beam depth as the steel beam 4.

[0070] In the structure of a beam-column joint 1D of the fourth embodiment, as shown in Fig. 6(a), in the beam-column joint 1D, the webs 31, 41 of the steel beams 3A, 4 in the main direction are reinforced by a doubler plate 7. Specifically, the entire circumference of the doubler plate 7 is fixed to the webs 31, 41 of the steel beams 3A, 4 by fillet welding or the like. Although not shown in the figure, in the beam-column joint 1D, the webs 31 of the steel beams 3C, 3D in the orthogonal direction are also reinforced by a doubler plate in the same manner.

[0071] In this way, in the structure of the beam-column joint 1D of the fourth embodiment, a doubler plate 7 is installed and reinforced on the webs 31, 41 of the steel beams 3A, 3C, 3D, 4 within the beam-column joint 1D, so that the shear strength of the doubler plate 7 can be added to the shear strength of the entire beam-column joint 1D.

[0072] In the structure of the beam-column joint 1D of the fourth embodiment, as shown in Fig. 6(a), holes 31h, 41h, 7h for filling concrete are provided in the portions of the webs 31, 41 of the steel beams 3A, 4 in the main direction that penetrate into the reinforced concrete column 2 and in the doubler plate 7 fixed to these portions. Although not shown in the figure, holes for filling concrete are also provided in the portions of the webs 31 of the steel beams 3C, 3D in the orthogonal direction that penetrate into the reinforced concrete column 2 and in the doubler plate fixed to these portions.

[0073] In the structure of the beam-column joint 1D of the fourth embodiment, the webs 31, 41 of the steel beams 3A, 3C, 3D, 4 in the beam-column joint 1C between the reinforced concrete column 2 and the steel beams 3A, 3C, 3D, 4 are reinforced by the doubler plate 7, so it becomes possible to open large holes 31h, 41h, 7h for filling concrete in the webs 31, 41 of the steel beams 3A, 3C, 3D, 4 in the beam-column joint 1D and the doubler plate 7. This improves the filling property of concrete in the beam-column joint 1D, making it easier to pour the concrete.

[0074] According to the structure of the beam-column joint 1D of the fourth embodiment, the same effects as those of the beam-column joint 1A of the first embodiment can be obtained. Fifth embodiment 7(a) and 7(b) show a vertical cross-sectional view and a perspective view of a structure of a beam-column joint 1E according to a fifth embodiment of the present invention.

[0075] As shown in Fig. 7(a) and Fig. 7(b), in the structure of the beam-column joint 1E of the fifth embodiment, four steel beams 3A, 3B, 5C, and 5D made of H-shaped steel are joined to the reinforced concrete column 2 so as to penetrate the column. The four steel beams 3A, 3B, 5C, and 5D are joined to the reinforced concrete column 2 so that their height positions are different from each other. Specifically, in the main direction, two steel beams 3A and 3B are arranged in the same structural plane and joined to the reinforced concrete column 2, and in the orthogonal direction, two steel beams 5C and 5D are arranged in the same structural plane and joined to the reinforced concrete column 2. The heights of the upper ends of the four steel beams 3A, 3B, 5C, and 5D are equal to each other, but the beam depths of the steel beams 5C and 5D are smaller than the beam depths of the steel beams 3A and 3B, and the height of the lower end of the steel beam 3A is lower than the height of the lower ends of the steel beams 5C and 5D. That is, the beam depth of steel beams 3A and 3B in the main direction: B D1(mm), Beam depth of steel beams 5C and 5D in the orthogonal direction: B If D3 (mm), then B D1> B It's D3.

[0076] As shown in Fig. 7(b), the two steel beams 5C, 5D joined to both sides of the reinforced concrete column 2 in the orthogonal direction are actually composed of a single H-shaped steel arranged to penetrate the reinforced concrete column 2. The steel beams 3A, 3B arranged in the main direction are welded to both sides of the H-shaped steel constituting the two steel beams 5C, 5D.

[0077] Furthermore, on both sides of the portion where the steel beams 3A, 3B arranged in the main direction penetrate the reinforced concrete column 2, anchoring portions 34 for holding the cover plates 22 are arranged so as to penetrate the H-shaped steel constituting the steel beams 3A, 3B in the main direction, and are welded to both sides of the H-shaped steel and to the bottom flanges 53 of the steel beams 5C, 5D in the orthogonal direction. The anchoring portions 34 are made of steel plates having a height equal to the difference between the beam depth of the steel beams 3A, 3B in the main direction and the beam depth of the steel beams 5C, 5D in the orthogonal direction.

[0078] In the structure of a beam-column joint 1E of the fifth embodiment, as shown in Fig. 7(a), within the beam-column joint 1E, the webs 31 of the steel beams 3A, 3B in the main direction are reinforced by a doubler plate 7. Specifically, the entire circumference of the doubler plate 7 is fixed to the webs 31 of the steel beams 3A, 3B by fillet welding or the like. Although not shown in the figure, in the same manner, within the beam-column joint 1E, the webs 51 of the steel beams 5C, 5D in the orthogonal direction are also reinforced by a doubler plate.

[0079] In this way, in the structure of the beam-column joint 1E of the fifth embodiment, a doubler plate 7 is installed and reinforced on the webs 31, 51 of the steel beams 3A, 3B, 5C, 5D within the beam-column joint 1E, so that the shear strength of the doubler plate 7 can be added to the shear strength of the entire beam-column joint 1E.

[0080] In the structure of the beam-column joint 1E of the fifth embodiment, as shown in Fig. 7(a), holes 31h, 7h for filling concrete are provided in the portions of the webs 31 of the steel beams 3A, 3B in the main direction that penetrate into the reinforced concrete column 2 and in the doubler plate 7 fixed to this portion. Although not shown in the figure, holes for filling concrete are also provided in the portions of the webs 51 of the steel beams 5C, 5D in the orthogonal direction that penetrate into the reinforced concrete column 2 and in the doubler plate fixed to this portion.

[0081] In the structure of the beam-column joint 1E of the fifth embodiment, the webs 31, 51 of the steel beams 3A, 3B, 5C, 5D in the beam-column joint 1E between the reinforced concrete column 2 and the steel beams 3A, 3B, 5C, 5D are reinforced by the doubler plate 7, so it becomes possible to open large holes 31h, 7h for filling concrete in the webs 31, 51 of the steel beams 3A, 3B, 5C, 5D in the beam-column joint 1E and the doubler plate 7. This improves the filling property of concrete in the beam-column joint 1E, making it easier to pour the concrete.

[0082] In other respects, the structure of the column-beam joint 1E of the fifth embodiment is configured similarly to the structure of the column-beam joint 1A of the first embodiment.

[0083] According to the structure of the beam-column joint 1E of the fifth embodiment, the same effects as those of the beam-column joint 1A of the first embodiment can be obtained. (Sixth embodiment) 8(a) and 8(b) are longitudinal cross-sectional views of a beam-column joint 1F according to a sixth embodiment of the present invention. Also, FIG. 8(c) is a perspective view of a beam-column joint 1F according to a sixth embodiment of the present invention. FIG. 8(a) also shows the distribution of shear force generated in the horizontal direction in a reinforced concrete column 2.

[0084] As shown in Fig. 8(a) to Fig. 8(c), the column-beam joint 1F of the sixth embodiment is a column-beam joint in which five steel beams 3A, 4, 5A, 5C, and 5D made of H-shaped steel are joined to a reinforced concrete column 2 so as to penetrate the column. The five steel beams 3A, 4, 5A, 5C, and 5D are joined to the reinforced concrete column 2 so as to be positioned differently in the height direction. In the main direction, the steel beams 3A and 5A are joined to one side of the reinforced concrete column 2 so as to be lined up vertically, and the steel beam 4 is joined to the other side of the reinforced concrete column 2. In the orthogonal direction, two steel beams 5C and 5D are joined to the reinforced concrete column 2. The beam depths of the steel beams 3A and 4 are equal to each other, and the beam depth of the steel beam 5A is smaller than the beam depth of the steel beams 3A and 4. The beam depth of steel beams 5C and 5D is smaller than the beam depth of steel beams 3A and 4, and larger than the beam depth of steel beam 5A.

[0085] In addition, the height of the upper end of the steel beam 3A is different from the height of the upper ends of the steel beams 4, 5A, 5C, and 5D, and the lower end of the upper steel beam 3A is higher than the upper ends of the lower steel beams 4, 5A, 5C, and 5D. In other words, the beam height of the upper steel beam 3A among the steel beams 3A, 4, and 5A arranged in the main direction: B D1(mm), beam depth of lower steel beam 4: B D2 (mm), center distance between upper steel beam 3A and lower steel beam 4: B If H (mm), the step ratio of steel beams 3A and 4 is 2 BH / ( B D1+ B D2)>1.

[0086] Among the steel beams 3A, 4, and 5A arranged in the main direction, the bottom flange 33 of the upper steel beam 3A and the top flange 42 of the lower steel beam 4 are joined by a tie plate 6. The tie plate 6 is arranged in the same plane as the webs 31, 41 of the upper steel beam 3A and the lower steel beam 4 joined by this tie plate 6.

[0087] As shown in Figures 8(a) to 8(c), the two steel beams 5C, 5D joined to both sides of the reinforced concrete column 2 in the orthogonal direction are joined to both sides of a portion where the lower steel beam 4 of the steel beams 3A, 4, 5A arranged in the main direction penetrates the reinforced concrete column 2. Specifically, the two steel beams 5C, 5D arranged in the orthogonal direction are arranged so as to penetrate the steel beam 4 arranged in the main direction, and are welded to both sides of the steel beam 4.

[0088] 8(a) to 8(c), on both sides of the portion where the upper steel beam 3A of the steel beams 3A, 4, and 5A arranged in the main direction penetrates the reinforced concrete column 2, anchoring portions 34 for holding the cover plates 22 are arranged so as to penetrate the steel beam 3A and are welded to both sides of the steel beam 3A. The anchoring portions 34 are made of H-shaped steel having the same beam depth as the steel beam 3A.

[0089] The lower flange of the H-shaped steel constituting the anchoring portion 34 and the upper flanges 52 of the steel beams 5C, 5D arranged in the perpendicular direction are joined by a tie plate 6. The tie plate 6 is arranged in the same plane as the web of the H-shaped steel constituting the anchoring portion 34 joined by this tie plate 6 and the webs 51 of the steel beams 5C, 5D.

[0090] 8(a), on both sides of the portion where the lower steel beam 4 of the steel beams 3A, 4, 5A arranged in the main direction penetrates the reinforced concrete column 2, at a position lower than the steel beams 5C, 5D in the orthogonal direction, anchoring portions 45 for holding the cover plates 22 are arranged to penetrate the steel beam 4 and are welded to both sides of the steel beam 4 and to the bottom flanges 53 of the steel beams 5C, 5D in the orthogonal direction. The anchoring portions 45 are made of steel plates having a height equal to the difference between the beam depth of the steel beam 4 in the main direction and the beam depth of the steel beams 5C, 5D in the orthogonal direction.

[0091] In the structure of a beam-column joint 1F of the sixth embodiment, as shown in Fig. 8(a), in the beam-column joint 1F, the webs 31, 41 of the steel beams 3A, 4 in the main direction are reinforced by a doubler plate 7. Specifically, the entire circumference of the doubler plate 7 is fixed to the webs 31, 41 of the steel beams 3A, 4 by fillet welding or the like. Similarly, as shown in Fig. 8(b), in the beam-column joint 1F, the webs 51 of the steel beams 5C, 5D in the orthogonal direction are also reinforced by the doubler plate 7.

[0092] In this way, in the structure of the beam-column joint 1F of the sixth embodiment, a doubler plate 7 is installed and reinforced on the webs 31, 41, 51 of the steel beams 3A, 4, 5C, 5D within the beam-column joint 1F, so that the shear strength of the doubler plate 7 can be added to the shear strength of the entire beam-column joint 1F.

[0093] In the structure of the beam-column joint 1F of the sixth embodiment, as shown in Fig. 8(a), the portions of the webs 31, 41 of the steel beams 3A, 4 in the main direction that penetrate the reinforced concrete column 2 and the doubler plate 7 fixed to these portions are provided with holes 31h, 41h, 7h for filling concrete. Similarly, as shown in Fig. 8(b), the portions of the webs 51 of the steel beams 5C, 5D in the orthogonal direction that penetrate the reinforced concrete column 2 and the doubler plate 7 fixed to these portions are provided with holes 51h, 7h for filling concrete.

[0094] In the structure of the beam-column joint 1F of the sixth embodiment, the webs 31, 41, 51 of the steel beams 3A, 4, 5C, 5D in the beam-column joint 1F between the reinforced concrete column 2 and the steel beams 3A, 4, 5A, 5C, 5D are reinforced by the doubler plate 7, so that it is possible to open large holes 31h, 41h, 51h, 7h for filling concrete in the webs 31, 41, 51 of the steel beams 3A, 4, 5C, 5D in the beam-column joint 1F and the doubler plate 7. This improves the filling property of concrete in the beam-column joint 1F, making it easier to pour concrete.

[0095] In addition, in the structure of the beam-column joint 1F of the sixth embodiment, as shown in FIG. 8(a), the connecting plate 6 that connects the upper steel beam 3A and the lower steel beam 4 among the steel beams 3A, 4, and 5A arranged in the main direction is also provided with a hole 6h for filling concrete. As shown in the shear force distribution shown on the right side of FIG. 8(a), in the structure of the beam-column joint 1F of the sixth embodiment, the shear force acting on the connecting plate 6 is smaller than the shear force acting on the webs 31 and 41 of the steel beams 3A and 4. Therefore, the hole diameter of the hole 6h provided in the connecting plate 6 can be made larger than the hole diameter of the holes 31h and 41h provided in the webs 31 and 41 of the steel beams 3A and 4. This further improves the filling property of concrete in the beam-column joint 1F, making it easier to pour concrete.

[0096] In other respects, the column-beam joint 1F of the sixth embodiment is configured similarly to the column-beam joint 1C of the third embodiment.

[0097] The column-beam joint 1F of the sixth embodiment provides the same effects as those of the column-beam joint 1C of the third embodiment. (When the end of the brace is connected to a column-beam joint) 9(a) and 9(b) are side views showing a state where an end of a brace 8 is joined to a column-beam joint 1A' in a structure of a column-beam joint 1A' according to a modification of the first embodiment of the present invention. FIG. 9(a) shows a case where the brace 8 joined to the column-beam joint 1A' is arranged in the same span as the steel beam 3A on the upper level. FIG. 9(b) shows a case where the brace 8 joined to the column-beam joint 1A' is arranged in the same span as the steel beam 4 on the lower level.

[0098] 10 shows a side view of a state where an end of a brace 8 is joined to a beam-column joint 1B' in a structure of a beam-column joint 1B' according to a modified example of the second embodiment of the present invention. Fig. 10 shows a case where the brace 8 joined to the beam-column joint 1B' is arranged in the same span as the steel beam 3A with a larger beam depth out of the steel beams 3A and 5 arranged in the main direction.

[0099] 11(a) and 11(b) are side views showing a state where an end of a brace 8 is joined to a column-beam joint 1C' in a structure of a column-beam joint 1C' according to a modification of the third embodiment of the present invention. FIG. 11(a) shows a case where the brace 8 joined to the column-beam joint 1C' is arranged in the same span as the steel beam 3A on the upper stage. FIG. 11(b) shows a case where the brace 8 joined to the column-beam joint 1C' is arranged in the same span as the steel beam 4 on the lower stage. In the structure of the column-beam joint 1C' according to the modification of the third embodiment, the doubler plate 7 is provided only in the portion of the web of the steel beam arranged in the span where the brace 8 is provided that penetrates the reinforced concrete column 2. That is, the doubler plate 7 is not provided in the portion of the web of the steel beam arranged in the span where the brace 8 is not provided that penetrates the reinforced concrete column 2. In other respects, the structure of the beam-column joint 1C' of the modified example of the third embodiment is configured similarly to the structure of the beam-column joint 1C of the third embodiment shown in Figures 5(a) to 5(c).

[0100] 12(a) and 12(b) are side views of a state where an end of a brace 8 is joined to a column beam joint 1D' in a structure of a column beam joint 1D' according to a modification of the fourth embodiment of the present invention. FIG. 12(a) shows a case where the brace 8 joined to the column beam joint 1D' is arranged in the same span as the steel beam 3A on the upper stage. FIG. 12(b) shows a case where the brace 8 joined to the column beam joint 1D' is arranged in the same span as the steel beam 4 on the lower stage. In the structure of the column beam joint 1D' of the modification of the fourth embodiment, the doubler plate 7 is provided only in the portion of the web of the steel beam arranged in the span where the brace 8 is provided that penetrates the reinforced concrete column 2. That is, the doubler plate 7 is not provided in the portion of the web of the steel beam arranged in the span where the brace 8 is not provided that penetrates the reinforced concrete column 2. In other respects, the structure of the beam-column joint 1D' of the modified example of the third embodiment is configured similarly to the structure of the beam-column joint 1D of the third embodiment shown in Figures 6(a) and 6(b).

[0101] 13 shows a side view of a state where an end of a brace 8 is joined to a column-beam joint 1E in a structure of a column-beam joint 1E according to a fifth embodiment of the present invention. Fig. 13 shows a case where the brace 8 joined to the column-beam joint 1E is arranged in the same span as one steel beam 3B of two steel beams 3A, 3B arranged in the main direction.

[0102] In each of the examples shown in Figures 9(a), 9(b), 10, 11(a), 11(b), 12(a), 12(b), and 13, the brace 8 is joined to beam-column joints 1A'-1D', 1E so that the central axis of the brace 8 is eccentric by a distance e with respect to the intersection of the center of the beam depth of the steel beam, which is arranged in the same span as the brace 8, and the material axis center of the reinforced concrete column 2. The portion of the web of the steel beam, which is arranged in the same span as the brace 8, that penetrates the reinforced concrete column 2 is reinforced by a doubler plate 7.

[0103] As shown in each example in Fig. 9(a), Fig. 9(b), Fig. 10, Fig. 11(a), Fig. 11(b), Fig. 12(a), Fig. 12(b), and Fig. 13, when the central axis of the brace 8 is eccentrically connected to the column-beam joints 1A'-1D', 1E, an additional bending moment acts on the column-beam joints 1A'-1D', 1E from the brace 8. As a result, the shear force acting on the column-beam joints 1A'-1D', 1E also becomes large. Therefore, as shown in Fig. 9(a), Fig. 9(b), Fig. 10, Fig. 11(a), Fig. 11(b), Fig. 12(a), Fig. 12(b), and Fig. 13, the part of the web of the steel beam arranged in the same span as the brace 8 that penetrates the reinforced concrete column 2 is reinforced with a doubler plate 7, so that the strength of the column-beam joints 1A'-1D', 1E can be sufficiently ensured with a relatively simple structure.

[0104] In the above embodiment, an example was described in which the column-beam joint structure of the present invention is applied to a column-beam joint with a beam-penetrating cover plate type, but the column-beam joint structure of the present invention can also be applied to a column-beam joint with a beam-penetrating shear reinforcement type. In this case, the end of the steel beam does not need to completely penetrate from one side to the opposite side of the reinforced concrete column, but it is sufficient that the end of the steel beam 3 penetrates from one side to the opposite side of the reinforced concrete column 2 by a length that allows the end of the steel beam to be sufficiently fixed in the column-beam joint.

[0105] In the structures of the beam-column joints 1A-1F, 1A'-1D' according to the above embodiments, the reinforced concrete column 2 and the steel beams 3A-3D, 4, 5A, 5C, 5D preferably have dimensions and material strengths that satisfy the following formula (1). This ensures sufficient shear strength of the beam-column joints 1A-1F, 1A'-1D'.

[0106] J Q dU < w Q+ h Q+ c Q……(1) However, in the above formula (1), J Q dU: Shear force acting on the column-beam joint at its ultimate state (N) w Q: Shear strength (N) of the web of a steel beam reinforced by a doubler plate in a beam-column joint panel. w Q= w τ U × w A e ……(2) h Q: Shear strength of the cover plate (N), c Q: Shear strength of concrete (N) c Q= cp k· C b· C D ……(3) In the above formula (2), w τ U :Shear strength of the web of a steel beam reinforced by a doubler plate in a beam-column joint panel (N / mm 2 ) w A e : Effective cross-sectional area of ​​the web of a steel beam reinforced by a doubler plate in a beam-column joint panel (mm 2 ) and w A e =0.9×( w t+0.8 d t)× C D ……(4) In the above formula (4), w t: thickness of the steel beam web in the beam-column joint (mm), d t: thickness of doubler plate (mm), C D: Depth of reinforced concrete column (mm), In the above formula (3), cp k: effective section modulus of concrete in the beam-column joint panel, cp k=0.32 C D / BD-0.028 C b / B b+0.204 ……(5) C b: Width of reinforced concrete column (mm) C D: Depth of reinforced concrete column (mm), In the above formula (5), B b: Width of steel beam (mm) B D: Depth of steel beam (mm) It is.

[0107] In the first embodiment, the beam depths of the four steel beams 3A, 3C, 3D, and 4 are equal to each other, and the height of the upper ends of the steel beams 3A, 3C, and 3D is different from the height of the upper end of the steel beam 4. Therefore, the distance between the upper surface of the upper flange 32 of the upper steel beam 3A, 3C, and 3D among these steel beams 3A, 3C, 3D, and 4 and the lower surface of the lower flange 43 of the lower steel beam 4 is set as follows: B Let's call it D.

[0108] In the case of the second embodiment, among the four steel beams 3B to 3D and 5A arranged so that the heights of the upper ends are equal to each other, the beam depth of the steel beams 3B to 3D having the largest beam depth is B Let's call it D.

[0109] In the third and fourth embodiments, the four steel beams 3A, 3C, 3D, and 4 are arranged so that the height of the top end of the steel beams 3A, 3C, and 3D is different from the height of the top end of the steel beam 4, but the beam depths of these four steel beams 3A, 3C, 3D, and 4 are equal to each other. Therefore, the beam depths of these steel beams 3A, 3C, 3D, and 4 are as follows: B Let's call it D.

[0110] In the case of the fifth embodiment, among the four steel beams 3A, 3B, 5C, and 5D arranged so that the heights of the upper ends are equal to each other, the beam depth of the steel beams 3A and 3B in the main direction in which the beam depth is the maximum is B Let's call it D.

[0111] In the sixth embodiment, five steel beams 3A, 4, 5A, 5C, and 5D are arranged such that the height of the top end of the steel beam 3A is different from the height of the top ends of the steel beams 4, 5A, 5C, and 5D. In the main direction, the steel beams 3A and 5A are joined to one side of the reinforced concrete column 2 in a vertical line, and the steel beam 4 is joined to the other side of the reinforced concrete column 2. In the orthogonal direction, two steel beams 5C and 5D are joined to the reinforced concrete column 2. Therefore, among the steel beams 3A, 4, and 5A arranged in the main direction, the beam depth of the steel beams 3A and 4 in the main direction, which has the maximum beam depth, is set to B Let's call it D.

[0112] Shear forces input from 3A~3D, 4, 5A, 5C, and 5D to beam-column joints 1A~1F and 1A´~1D´ J In the column-beam joints 1A-1F and 1A'-1D', Q is shared and borne by the webs 31, 41, 51 of 3A-3D, 4, 5A, 5C, and 5D, the doubler plate 7, the cover plate 22, and the concrete. In other words, the total shear force borne by the webs 31, 41, 51 of 3A-3D, 4, 5A, 5C, and 5D and the doubler plate 7 is w Q, the shear force borne by the cover plate 22 h Q: The shear force borne by the concrete cp If we call it Q, J Q= w Q+ h Q+ cp The answer is Q.

[0113] Similarly, the ultimate shear strength of column-beam joints 1A-1F and 1A´-1D´ J Q sU is the total shear strength of webs 31, 41, 51 and doubler plate 7 of 3A-3D, 4, 5A, 5C, and 5D. w Q sU , the shear strength of the cover plate 22 h Q sU , the shear strength of concrete cp Q sU Then, J Q sU = w Q sU + h QsU + cp Q sU It becomes.

[0114] Shear strength of beam-column joints J Q sU is the shear force acting on column-beam joints 1A-1F and 1A'-1D' at the ultimate state (during an earthquake) of column-beam joints 1A-1F and 1A'-1D' J Q dU That is, J Q sU > J Q dU The above formula (1) is based on this.

[0115] In this way, in the structure of the beam-column joint of each of the above embodiments, the webs 31, 41, 51 of 3A-3D, 4, 5A, 5C, 5D in the beam-column joints 1A-1F, 1A'-1D' are reinforced by the doubler plate 7, so that the shear strength of the doubler plate 7 can be added to the shear strength of the entire beam-column joints 1A-1F, 1A'-1D'. However, it has not been established so far how the burden ratio of each resistance element changes due to the provision of the doubler plate 7, and what proportion of the total cross-sectional area of ​​the doubler plate 7 effectively contributes to the shear strength. In the structure of the beam-column joint of each of the above embodiments, as described later, based on the new knowledge of the inventors that 80% or more of the total cross-sectional area of ​​the doubler plate 7 effectively contributes to the shear strength, this contribution rate is reflected in the above formula (4). Furthermore, when no support plate is provided at the column-beam joints 1A-1F, 1A'-1D' and only a thinner cover plate 22 is provided, as described below, the inventors have newly discovered that approximately 90% of the cross-sectional area of ​​the webs 31, 41, 51 reinforced by the doubler plate effectively contributes to the shear strength, and this contribution rate is also reflected in the above equation (4).

[0116] In the above formula (4), dThe coefficient 0.8 applied to t (the thickness of the doubler plate) may be changed to a smaller value, for example, 0.7, 0.6, etc. Similarly, the coefficient 0.9 applied to the entire right side of the above equation (4) may be changed to a smaller value, for example, 0.8, 0.7, etc. In this way, J Q dU The safety factor of the column-beam joint against the shear force acting on the column-beam joint at its ultimate state can be increased.

[0117] FIG. 14 shows the effective section modulus of concrete in the column-beam joint structure of the present invention. cp k and the ratio of column depth to beam depth C D / B FIG. 15 shows the relationship between the effective section modulus of the concrete panel in the beam-column joint structure of the present invention and the effective section modulus of the concrete panel. cp k and the ratio of column width to beam width C b / B Shows the relationship with b.

[0118] As shown in Figures 14 and 15, the ratio of column depth to beam depth C D / B As D increases, the effective section modulus of concrete cp There is a tendency for k to become larger. Also, the ratio of column width to beam width C b / B As b increases, the effective section modulus of concrete cp The above formula (5) is the ratio of column depth to beam depth. C D / B D, and the ratio of column width to beam width C b / B b is the effective section modulus of concrete cp The effect of the concrete on k is evaluated in terms of the proportional relationship shown by the dashed lines in Figures 14 and 15, and the effective section modulus of concrete is calculated using this mechanical model. cp k is defined. [Explanation of symbols]

[0119] 1A~1F, 1A´~1D´ Column beam joint 2. Reinforced concrete columns 21 Main reinforcement 22 Covering board 3A~3D, 4, 5A, 5C, 5D steel beam 31, 41, 51 Web 32, 42, 52 Top flange 33, 43, 53 Bottom flange 34, 44, 45 Fixing section 6. Connecting board 7 Doubler Plate 31h, 41h, 51h, 6h, 7h hole 8. Braces

Claims

1. A structure of a column-beam joint in which a plurality of steel beams are inserted into a reinforced concrete column, The plurality of steel beams are joined to the reinforced concrete columns so that their positions in the height direction are different from each other, A cover plate is provided so as to surround the concrete poured continuously from the reinforced concrete columns above and below the column-beam joint, A column-beam joint structure in which a doubler plate is installed in the portion of the web of the steel beam that is located within the column-beam joint and surrounded by the cover plate.

2. At least two of the plurality of steel beams are arranged within the same structural plane, and the lower end of an upper steel beam, which is a steel beam having a higher center of beam height, is lower than the upper end of a lower steel beam, which is a steel beam having a lower center of beam height; The column-beam joint structure according to claim 1 , wherein the doubler plate is disposed at a height between a lower end of the upper steel beam and an upper end of the lower steel beam.

3. 2. The column-beam joint structure according to claim 1, further comprising an end of a brace connected to the column-beam joint between the reinforced concrete column and the steel beam.

4. 3. The column-beam joint structure according to claim 2, further comprising an end of a brace connected to the column-beam joint between the reinforced concrete column and the steel beam.

5. At least two of the plurality of steel beams are arranged within the same structural plane, and the lower end of an upper steel beam, which is a steel beam having a higher center of beam height among the two steel beams, is higher than the upper end of a lower steel beam, which is a steel beam having a lower center of beam height; The lower flange of the upper steel beam and the upper flange of the lower steel beam are joined by a connecting plate, The ends of the brace are further joined to the column-beam joints between the reinforced concrete column and the two steel beams, 2. The column-beam joint structure according to claim 1, wherein the doubler plate is disposed in a portion of the web of the steel beam that is disposed in the same span as the brace, among the two steel beams, that penetrates the reinforced concrete column.

6. 6. The column-beam joint structure according to claim 5, wherein the doubler plate is not arranged in a portion of the web of the steel beam that is not arranged in the same span as the brace, the portion penetrating the reinforced concrete column.

7. The structure of any one of claims 1 to 6, wherein a hole for filling concrete is provided in the portion of the web of the steel beam that penetrates the reinforced concrete column and in the doubler plate.

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