Column joint structure and method for constructing a column joint structure

Abstract

To provide a column joint structure 1 with excellent workability by reducing the height of a joint steel pipe portion 32.SOLUTION: A column joint structure 1 is a column joint structure 1 that joins a column-beam joint 10, at which a steel beam 14 is joined to a steel pipe column 12, to a reinforced concrete column 30. The joint structure 1 includes a tubular joint steel pipe section 32 that protrudes upward from the column-beam joint 10, and an annular horizontal fixing plate 34 that protrudes horizontally inward from an inner surface 32a of the joint steel pipe section 32. The reinforced concrete column 30 includes a plurality of main reinforcements 38 that extend inside the joint steel pipe section 32. Lower ends 38a of the plurality of main reinforcements 38 are fixed to the horizontal fixing plate 34.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a column joint structure formed by connecting a steel pipe column and a reinforced concrete column, and a method for constructing the column joint structure.

Background Art

[0002] In recent years, RC (reinforced concrete) high-rise buildings have been widely adopted in large-scale redevelopment projects. Many of these high-rise buildings are multi-purpose complex facilities. Since different uses require different column spans and floor heights, etc., different structural types suitable for the framework configuration are also required according to the use.

[0003] For example, uses that require relatively large column spans such as stores and offices are arranged on the lower floors, and uses that require small column spans and high-rigidity and sound-insulating spaces such as residences and hotels are arranged on the upper floors. In that case, S structure (steel frame structure) or CFT structure (concrete-filled steel tube structure) may be adopted on the lower floors, and RC structure may be adopted on the upper floors. Thus, it is required to switch the structural type of the framework in the middle floor and construct a reasonable structure suitable for the use of the facility.

[0004] Conventionally, joint structures for connecting columns of S structure or CFT structure to RC columns in such middle floors have been proposed (for example, Patent Documents 1 and 2). In the joint structure between the joint steel pipe extending upward from the CFT column in Patent Document 1 and the RC column on the upper floor, since the main reinforcement of the RC column and the joint steel pipe are not directly joined, stress transmission is performed through concrete. Also, in the joint structure between the CFT column and the RC column in Patent Document 2, the main reinforcement of the RC column is extended to the upper end of the CFT column beyond the column-beam joint and fixed with plate nuts, and stress transmission is performed through concrete.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] However, in the joint structures described in Patent Documents 1 and 2, the main reinforcement of the RC column and the connecting steel pipe are not directly joined, and stress is transmitted through the concrete. As a result, in the joint structure of Patent Document 1, the height of the connecting steel pipe is relatively high, and in the joint structure of Patent Document 2, the main reinforcement extends to the CFT column, which tends to reduce the workability of the main reinforcement during construction.

[0007] Therefore, the present invention provides a column joint structure and a method for constructing a column joint structure that offer excellent workability by directly joining the main reinforcement of the RC column and the connecting steel pipe to transmit stress, thereby reducing the height of the connecting steel pipe section. [Means for solving the problem]

[0008] The present invention has been made to solve at least some of the above-mentioned problems and can be realized in the following embodiments or applications.

[0009] [1] One embodiment of the column joint structure according to the present invention is: A column joint structure that connects a steel pipe column to a reinforced concrete column, where a steel beam is joined to the column-beam joint. The aforementioned joint structure is A cylindrical connecting steel pipe section protruding upward from the column-beam joint, An annular horizontal fixing plate protruding horizontally inward from the inner surface of the joined steel pipe section, Equipped with, The reinforced concrete column is provided with a plurality of main reinforcements extending into the connecting steel pipe section. The lower ends of the plurality of main reinforcements are fixed to the horizontal fixing plate.

[0010] [2] In the column joint structure, The aforementioned joining structure further comprises a plurality of vertical fixing plates that protrude inward from the inner surface and extend vertically, The horizontal fixing plate can be joined to the plurality of vertical fixing plates.

[0011] [3] In the column joint structure, The aforementioned horizontal fixing plate is the first horizontal fixing plate, The joining structure further includes an annular second horizontal fixing plate positioned at a space above the first horizontal fixing plate, projecting horizontally inward from the inner surface of the joining steel pipe portion. The second horizontal fixing plate has multiple through holes formed at intervals from each other and is joined to the multiple vertical fixing plates. The multiple main reinforcements can pass through the multiple through holes.

[0012] [4] In the column joint structure, The aforementioned multiple main reinforcements can be fixed to the second horizontal fixing plate.

[0013] [5] One embodiment of the method for constructing a column joint structure according to the present invention is: A method for constructing a column joint structure that connects a steel beam to a steel pipe column at a column-beam joint and a reinforced concrete column, A cylindrical connecting steel pipe section protrudes upward from the column-beam joint, and an annular horizontal fixing plate protrudes horizontally inward from the inner surface of the connecting steel pipe section. The method is characterized by fixing the lower ends of multiple main reinforcing bars of the reinforced concrete column to the horizontal fixing plate, and then pouring concrete into the connecting steel pipe section. [Effects of the Invention]

[0014] According to the column joint structure and method for constructing the column joint structure of the present invention, the workability of the main reinforcement can be improved by reducing the height of the joining steel pipe section. [Brief explanation of the drawing]

[0015] [Figure 1]It is a longitudinal sectional view schematically showing the column joint structure according to the first embodiment. [Figure 2] They are (a) the A-A sectional view and (b) the B-B sectional view in FIG. 1. [Figure 3] It is a longitudinal sectional view schematically showing the column joint structure according to the second embodiment. [Figure 4] It is the C-C sectional view in FIG. 3. [Figure 5] It is a longitudinal sectional view schematically showing the column joint structure according to the third embodiment. [Figure 6] It is a graph showing the relationship between the column shear force and the column member angle of the test specimen at a tensile axial force of 3089 kN (equivalent to 0.5 times the tensile yield strength of the reinforced concrete column). <![CDATA[ [Figure 7] ]] It is a graph showing the relationship between the column shear force and the column member angle of the test specimen at a compressive axial force of 6943 kN (equivalent to 0.2 times the compressive strength of the reinforced concrete column).

Embodiments for Carrying out the Invention

[0016] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. Note that the embodiments described below do not unduly limit the content of the present invention described in the claims. Also, not all of the configurations described below are essential constituent elements of the present invention. .

[0017] 1. First Embodiment 1-1. Column Joint Structure Using FIGS. 1 and 2, the column joint structure 1 according to the first embodiment will be described below. FIG. 1 is a longitudinal sectional view schematically showing the column joint structure 1 according to the first embodiment, FIG. 2(a) is the A-A sectional view in FIG. 1, and FIG. 2(b) is the B-B sectional view in FIG. 1. In FIG. 2(a), the vertical fixing plate 36 and the fixing member 40 below the horizontal fixing plate 34 are shown by broken lines, and in FIG. 2(b), the state where the concrete 17 (lath) is placed inside the joint steel pipe portion 32 is shown.

[0018] As shown in Figures 1 and 2, the column joint structure 1 according to the first embodiment is a column joint structure 1 that joins a column-beam joint 10, to which a steel beam 14 is joined to a steel pipe column 12, to a reinforced concrete column 30. Buildings to which the joint structure 1 is applied include, for example, skyscrapers, in which the structural type of the framework of the lower floors and the structural type of the framework of the upper floors are different. In this embodiment, an example of a building in which CFT construction is used for the lower floors and RC construction is used for the upper floors will be described, but steel construction may be used instead of CFT construction for the lower floors.

[0019] The column-beam joint 10 constitutes part of the CFT structure in the lower floor of the building and comprises a steel pipe column 12 with a rectangular cross-section, for example, extending downward from the column-beam joint 10, a plurality of steel beams 14 extending horizontally outward from the steel pipe column 12, and concrete 17 cast inside the steel pipe column 12. The upper end of the steel pipe column 12 is provided with an annular diaphragm 16 in which a casting hole 16a is formed. Instead of the diaphragm 16, an external diaphragm extending outward from the steel pipe column 12 may be provided. Figure 2 describes a rectangular steel pipe column 12, but it may also be cylindrical.

[0020] The reinforced concrete column 30 constitutes part of the RC structure in the upper part of the building. The reinforced concrete column 30 comprises a plurality of main reinforcements 38 extending into the connecting steel pipe section 32, stirrups (not shown), and concrete 17. In Figures 1 and 2, the areas where concrete 17 has been poured are indicated by shading. Multiple main reinforcements 38 are arranged along the outer circumference of the reinforced concrete column 30. The plurality of main reinforcements 38 extend within the reinforced concrete column 30 in the direction along the Y axis (vertical direction). The main reinforcements 38 may be extended longitudinally by, for example, a joint section 39. The joint section 39 is shown as an example of a mechanical joint, but other known joint types may also be used.

[0021] The joint structure 1 comprises a joint steel pipe section 32 and a horizontal fixing plate 34. The joint structure 1 may further comprise a plurality of vertical fixing plates 36. The horizontal fixing plates 34 and vertical fixing plates 36 are sometimes called rib plates. The joint structure 1 is located between the column-beam joint section 10 and the reinforced concrete column 30, rationally joining different framing structures over a relatively short distance. Furthermore, the joint structure 1 does not affect the seismic resistance of the reinforced concrete column 30. In this embodiment, an example with vertical fixing plates 36 is described, but even without the vertical fixing plates 36, the horizontal fixing plates 34 have the effect of transmitting the tensile force generated in the main reinforcement 38 of the reinforced concrete column 30 to the joint steel pipe section 32. And, by further comprising vertical fixing plates 36 as in this embodiment, it is possible to obtain the effect of transmitting a greater tensile force than when there are no vertical fixing plates 36.

[0022] The connecting steel pipe section 32 protrudes upward from the column-beam joint 10. The connecting steel pipe section 32 is a cylindrical steel pipe, with its lower end integrally joined to the column-beam joint 10 and its upper end open. As shown in Figure 2, the connecting steel pipe section 32 is a rectangular tube with a roughly square cross-section, but it may also be cylindrical. The connecting steel pipe section 32 can be made of the same material as the steel pipe used in the column-beam joint 10 of the CFT structure. A horizontal fixing plate 34 and a vertical fixing plate 36 are welded to the inner surface 32a of the connecting steel pipe section 32 to form a single unit. The connecting steel pipe section 32 is assembled in the factory and transported to the construction site before being joined to the column-beam joint. The joint 10 may be welded to the joint 32, or it may be assembled integrally with the column-beam joint 10 at the factory and then transported to the construction site. Inside the joint steel pipe section 32, multiple main reinforcement bars 38 are provided extending from above, and the lower ends 38a of each of the multiple main reinforcement bars 38 are fixed to the horizontal fixing plate 34. The joint steel pipe section 32 and the main reinforcement bars 38 below the joint section 39 may be produced in the factory using precast concrete (PCa) and transported to the construction site, in which case a pouring hole for pouring concrete into the lower part can be provided in the PCa.

[0023] The horizontal fixing plate 34 is an annular steel plate that protrudes horizontally (along the X-axis) inward from the inner surface 32a of the connecting steel pipe section 32. The horizontal fixing plate 34 is joined to a plurality of vertical fixing plates 36. The outer edge of the horizontal fixing plate 34 is welded to the inner surface 32a to form a single unit. The horizontal fixing plate 34 is installed at a height as close as possible to the column-beam joint 10, within a range that does not affect the workability of attaching the fixing member 40, described later, to the lower end 38a of the main reinforcement bars 38. As shown in Figure 2(a), the horizontal fixing plate 34 is formed along the inner surface 32a of the rectangular tubular connecting steel pipe section 32, and is therefore in the shape of a square with a square opening in the center. The horizontal fixing plate 34 has a plurality of through holes along the Y-axis at positions corresponding to all the main reinforcement bars 38 that extend into the connecting steel pipe section 32. The main reinforcement bars 38 are fixed to the horizontal fixing plate 34 by the fixing member 40 with their lower ends 38a inserted through these through holes. Fixing with the fixing member 40 can be done, for example, by screwing a set of nut-shaped fixing members 40 onto a screw formed on the lower end 38a of the main reinforcement bar 38, thereby sandwiching and fixing the horizontal fixing plate 34. As the fixing member 40, a known fixing device used for fixing reinforcement bars and steel plates can be used. The lower end 38a of the main reinforcement bar 38 is positioned at a height that does not hinder the fixing work of the fixing member 40 between it and the diaphragm 16, and is positioned as low as possible in order to keep the height of the joint steel pipe section 32 down.

[0024] The vertical fixing plate 36 is, for example, a steel plate that protrudes inward from the inner surface 32a of the joining steel pipe section 32 and extends vertically (along the Y-axis). The outer end of the vertical fixing plate 36 is welded to the inner surface 32a and fixed integrally with the joining steel pipe section 32. As shown in Figure 1, a pair of upper and lower vertical fixing plates 36 are welded to the upper and lower surfaces of the horizontal fixing plate 34 so as to sandwich it. By fixing the vertical fixing plate 36 to the horizontal fixing plate 34, deformation of the horizontal fixing plate 34 in the vertical direction is suppressed when the main reinforcement 38 is subjected to vertical stress due to seismic motion, thereby preventing damage to the joint structure 1. The lower end of the vertical fixing plate 36 may be welded to the upper surface of the diaphragm 16. The vertical fixing plate 36 may protrude from the inner surface 32a by, for example, the same width as the protrusion width of the horizontal fixing plate 34, and it is preferable that it protrudes from the inner surface 32a at least to the position where the main reinforcement 38 is fixed.

[0025] As shown in Figure 2(b), the vertical fixing plates 36 are provided between adjacent main reinforcement bars 38, but this is not limited to this arrangement. The number of plates may be fewer or more than in this example to ensure the strength required by the design. In this example, two vertical fixing plates 36 are used to sandwich and fix the annular horizontal fixing plate 34, but since the horizontal fixing plate 34 is integrated with the vertical fixing plate 36, the vertical fixing plate 36 may be treated as a single continuous plate, with short horizontal fixing plates 34 integrated between each adjacent vertical fixing plate 36. In this case as well, the horizontal fixing plates 34 are continuous in an annular shape via the vertical fixing plates 36.

[0026] As described above, with column joint structure 1, the joint steel pipe section 32 is firmly joined to the main reinforcement 38 via the horizontal fixing plate 34, so the height of the joint steel pipe section 32 can be kept low. A lower height for the joint steel pipe section 32 makes it easier to reach the lower end 38a of the main reinforcement 38 during construction, improving work efficiency. In addition, the horizontal fixing plate 34 is reinforced by the vertical fixing plate 36, which allows for the transmission of greater tensile forces generated in the main reinforcement 38 to the joint steel pipe section 32.

[0027] 1-2. Method for constructing column joint structures The method for constructing column joint structure 1 will be explained below using Figures 1 and 2. The construction method in forms 2 and 3 is basically the same as the construction method in the first embodiment.

[0028] The method for constructing the column joint structure 1 according to this embodiment is a method for constructing a column joint structure 1 that connects a column-beam joint 10, to which a steel beam 14 is joined to a steel pipe column 12, with a reinforced concrete column 30.

[0029] First, the lower section is constructed using CFT (Concrete-Filled Steel Tube) construction. The pouring of concrete 17 into the steel pipe columns 12 may be carried out together with the reinforced concrete columns 30 of the upper section.

[0030] Above the lower column-beam joint 10, a cylindrical connecting steel pipe section 32 protrudes upward from the column-beam joint 10, and an annular horizontal fixing plate 34 protrudes horizontally inward from the inner surface 32a of the connecting steel pipe section 32. In this embodiment, further vertical fixing plates 36 protrude inward from the inner surface 32a and extend vertically, and the horizontal fixing plate 34 is joined to the multiple vertical fixing plates 36. The connecting steel pipe section 32 may be welded to the column-beam joint 10 at the construction site with the horizontal fixing plates 34 and vertical fixing plates 36 fixed, or it may be manufactured integrally with the column-beam joint 10 in advance at a factory and fixed to the CFT column.

[0031] Next, after fixing the lower ends 38a of the multiple main reinforcements 38 of the reinforced concrete column 30 to the horizontal fixing plate 34, concrete 17 is poured into the connecting steel pipe section 32. As described above, the connecting structure 1 allows the height of the connecting steel pipe section 32 to be kept low, resulting in excellent workability. The concrete 17 is also filled into the lower steel pipe column 12 through the pouring holes 16a opened in the diaphragm 16.

[0032] 2. Second Embodiment The column joint structure 1a according to the second embodiment will be described below with reference to Figures 3 and 4. Figure 3 is a schematic longitudinal section view showing the column joint structure 1a according to the second embodiment, and Figure 4 is a cross-sectional view of CC in Figure 3. The basic configuration of the joint structure 1a is the same as that of the joint structure 1 according to the first embodiment, so the explanation of the overlapping parts will be omitted. Also, the DD section in Figure 3 is the same as in Figure 2(a), so it will not be shown.

[0033] As shown in Figure 3, the joint structure 1a differs from the first embodiment in that two horizontal fixing plates (34a, 35) are provided above and below the inner surface 32a of the jointed steel pipe section 32. The horizontal fixing plate 34 in the first embodiment corresponds to the first horizontal fixing plate 34a in the second embodiment. The joint structure 1a further includes an annular second horizontal fixing plate 35 that protrudes horizontally inward from the inner surface 32a of the jointed steel pipe section 32 at a spaced position above the first horizontal fixing plate 34a. The jointed steel pipe section 32 in the second embodiment is slightly taller than the jointed steel pipe section 32 in the first embodiment due to the provision of the second horizontal fixing plate 35.

[0034] As shown in Figure 4, the second horizontal fixing plate 35 may have the same shape as the first horizontal fixing plate 34a. The second horizontal fixing plate 35 is an annular steel plate. The first horizontal fixing plate 34a and the second horizontal fixing plate 35 are joined to a plurality of vertical fixing plates 36. The outer edge of the second horizontal fixing plate 35 is welded to the inner surface 32a to form a single unit. The second horizontal fixing plate 35 is in the shape of a square with a square opening in the center, but as described above, it may also be shaped to match the shape of the inner surface 32a of the joining steel pipe section 32 together with the first horizontal fixing plate 34a. As shown in Figure 4, the second horizontal fixing plate 35 has a plurality of through holes 35a formed at intervals from each other. The through holes 35a open at positions corresponding to all the main reinforcement bars 38 that extend into the joining steel pipe section 32. Note that in Figure 4, due to space limitations for writing reference numerals, the reference numerals for the through holes 35a are only written at the four corners. The plurality of main reinforcement bars 38 pass through the plurality of through holes 35a. Each main reinforcement bar 38 is inserted through the through hole 35a, and its lower end 38a is fixed to the first horizontal fixing plate 34a by a fixing member 40.

[0035] The upper end of the vertical fixing plate 36 is welded to the lower surface of the second horizontal fixing plate 35 to form a single unit. The second horizontal fixing plate 35 is prevented from deforming upward by the vertical fixing plate 36. By providing the second horizontal fixing plate 35 above the first horizontal fixing plate 34a, it is possible to prevent the concrete 17 above the first horizontal fixing plate 34a from deforming upward and bulging due to the upward pulling of the main reinforcement bars 38. By suppressing such deformation, damage to the joint structure 1a due to seismic motion can be prevented.

[0036] Although the jointed steel pipe section 32 of the second embodiment is taller than the jointed steel pipe section 32 of the first embodiment, it is firmly joined via the main reinforcement bars 38 and the first horizontal fixing plate 34a, so the height described in Patent Document 1 is not necessary. Therefore, workability inside the jointed steel pipe section 32 is good.

[0037] The method for constructing the column joint structure 1a differs in that the main reinforcement bars 38 are inserted into the second horizontal fixing plate 35 and then the lower end 38a is fixed with a fixing member 40. However, the other steps are basically the same as the construction method according to the first embodiment, so a detailed explanation is omitted.

[0038] 3. Third Embodiment The column joint structure 1b according to the third embodiment will be described below with reference to Figure 5. Figure 5 is a schematic longitudinal cross-sectional view showing the column joint structure 1b according to the third embodiment. The basic configuration of the joint structure 1b is the same as that of the joint structure 1 according to the first embodiment and the joint structure 1a according to the second embodiment, so the explanation of the overlapping parts will be omitted.

[0039] As shown in Figure 5, the joint structure 1b differs from the second embodiment in that the main reinforcement bars 38 are fixed to the second horizontal fixing plate 35 by fixing members 40. Multiple main reinforcement bars 38 are fixed to the second horizontal fixing plate 35. The fixing members 40 may be the same as the fixing members 40 used in the first embodiment.

[0040] Since the main reinforcement bars 38 are also fixed to the second horizontal fixing plate 35, the connection between the main reinforcement bars 38 and the connecting steel pipe section 32 becomes stronger compared to the first and second embodiments. Although the second and third embodiments both describe examples using a vertical fixing plate 36, the vertical fixing plate 36 may be omitted, as described in the first embodiment.

[0041] The method for constructing the column joint structure 1b differs in that the main reinforcement bars 38 are inserted through the second horizontal fixing plate 35 and fixed with fixing members 40, and then the lower end 38a is further fixed with fixing members 40. However, the other steps are basically the same as the construction method according to the first embodiment, so their explanation will be omitted. [Examples]

[0042] Static cyclic loading experiments were conducted using test specimens employing the joint structures 1a and 1b of the second and third embodiments described above. The following explanation will use the reference numerals in Figures 3 to 5.

[0043] (Test specimen) A test specimen was fabricated in which a reinforced concrete column 30 with a height of 3300 mm was constructed between two column-beam joints 10 made of CFT (Concrete-Fiber Tensioned Steel). A connecting steel pipe section 32 with a square cross-section was welded to one of the column-beam joints 10, and connecting structures 1a and 1b were constructed inside it. Two first horizontal fixing plates 34a and a second horizontal fixing plate 35, and 24 vertical fixing plates 36 extending from the second horizontal fixing plate 35 to the diaphragm 16 were welded to the inner surface 32a of the connecting steel pipe section 32. The lower ends 38a of all main reinforcement bars 38 were fixed using anchoring plates (fixing members 40) with the bars penetrating the first horizontal fixing plate 34a. The jointed steel pipe section 32 had a height of 400 mm, a width and depth of 704 mm, and a plate thickness of 32 mm. The two horizontal fixing plates (34a, 35) had a central opening of 440 x 440 mm, a width and depth of 640 mm, and a plate thickness of 28 mm. The vertical fixing plate 36 had a height of 300 mm and a plate thickness of 12 mm. The horizontal fixing plates (34a, 35) were provided with 24 through holes corresponding to the 24 main reinforcing bars 38. Of these, the 13 through holes 35a of the second horizontal fixing plate 35 on the right side when viewed from the front did not fix the main reinforcing bars 38, while the 11 through holes 35a on the left side fixed the main reinforcing bars 38 with anchoring plates (fixing members 40).

[0044] (Experimental conditions) The test specimen was subjected to repeated horizontal loading tests by varying the axial force to +3089kN (tensile axial force: equivalent to 0.5 times the tensile yield strength of reinforced concrete column 30) and -6943kN (compressive axial force: equivalent to 0.2 times the compressive strength of reinforced concrete column 30), while maintaining each axial force constant and gradually increasing the deformation angle. The horizontal loading was controlled based on the column member angle (=δ / h), which is obtained by dividing the horizontal displacement δ at the center position of the loaded beam by the height h from the top surface of the lower stub to the bottom surface of the upper stub.

[0045] (Experimental results) The experimental results are shown in Figures 6 and 7. Figure 6 is a graph showing the relationship between the column shear force and column angle of the test specimen at a tensile axial force of 3089 kN, and Figure 7 is a graph showing the relationship between the column shear force and column angle of the test specimen at a compressive axial force of 6943 kN. In each graph, the vertical axis represents the column shear force (kN), and the horizontal axis represents the column angle (×10). -3 It is rad.

[0046] The dashed lines in each figure represent the calculated bending strength of the reinforced concrete column 30. The experimental values ​​of column shear force shown in each graph exceed the calculated bending strength of the reinforced concrete column 30, indicating that the column connection structures 1a and 1b do not affect the seismic resistance of the reinforced concrete column 30. Furthermore, the connection structures 1a and 1b remained undamaged throughout the experiment.

[0047] The present invention is not limited to the embodiments described above, and various further modifications are possible. For example, the present invention includes configurations that are substantially identical to the configurations described in the embodiments (for example, configurations with the same function, method, and result, or configurations with the same purpose and effect). The present invention also includes configurations in which non-essential parts of the configurations described in the embodiments are replaced. The present invention also includes configurations that produce the same effects or achieve the same purpose as the configurations described in the embodiments. Furthermore, the present invention includes configurations that add known technology to the configurations described in the embodiments. [Explanation of symbols]

[0048] 1,1a,1b...Column joint structure, 10...Column-beam joint, 12...Steel pipe column, 14...Steel beam, 16...Diaphragm, 16a...Casting hole, 17...Concrete, 30...Reinforced concrete column, 32...Joint steel pipe section, 32a...Inner surface, 34...Horizontal fixing plate, 34a...First horizontal fixing plate, 35...Second horizontal fixing plate, 35a...Through hole, 36...Vertical fixing plate, 38...Main reinforcement, 38a...Bottom end, 39...Joint section, 40...Fixing member

Claims

1. A column joint structure that connects a steel pipe column to a reinforced concrete column, where a steel beam is joined to the column-beam joint. The aforementioned joint structure is A cylindrical connecting steel pipe section protruding upward from the column-beam joint, An annular horizontal fixing plate protruding horizontally inward from the inner surface of the joined steel pipe section, Equipped with, The reinforced concrete column is provided with a plurality of main reinforcements extending into the connecting steel pipe section. The lower ends of the multiple main reinforcing bars are fixed to the horizontal fixing plate, forming a column joint structure.

2. In the column joint structure described in claim 1, The device further comprises a plurality of vertical fixing plates that protrude inward from the inner surface and extend vertically, The horizontal fixing plate is joined to the plurality of vertical fixing plates, forming a column joint structure.

3. In the column joint structure described in claim 2, The aforementioned horizontal fixing plate is the first horizontal fixing plate, The joining structure further includes an annular second horizontal fixing plate that protrudes horizontally inward from the inner surface of the joining steel pipe portion at a space above the first horizontal fixing plate, The second horizontal fixing plate has multiple through holes formed at intervals from each other and is joined to the multiple vertical fixing plates. The aforementioned multiple main reinforcements pass through the aforementioned multiple through holes, forming a column joint structure.

4. In the column joint structure described in claim 3, The aforementioned multiple main reinforcements are fixed to the second horizontal fixing plate, forming a column joint structure.

5. A method for constructing a column joint structure that connects a steel beam to a steel pipe column at a column-beam joint and a reinforced concrete column, A cylindrical connecting steel pipe section protrudes upward from the column-beam joint, and an annular horizontal fixing plate protrudes horizontally inward from the inner surface of the connecting steel pipe section. A method for constructing a column joint structure, comprising fixing the lower ends of multiple main reinforcing bars of the reinforced concrete column to the horizontal fixing plate, and then pouring concrete into the joint steel pipe section.

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