Connection structure, connection method and steel column

Abstract

To provide a connection structure and a connection method which can surely transmit tensile force and a moment of a horizontal member of reinforced concrete to a steel column, and a steel column used in the same.SOLUTION: A connection structure 10 in which a slab 20 of reinforced concrete is connected to a square steel pipe column 11 includes two layers of horizontal steel plates 15 and 16 which are fixed to the outer periphery of the square steel pipe column 11 and are buried in the slab 20, and a plurality of anchoring reinforcements 31 to 34. The anchoring reinforcement 31 to 34 are fixed to notch parts 15a to 16b formed in the horizontal steel plates 15 and 16, and transmit tensile force to slab reinforcements 21 and 22 which are buried at positions separated from one another in a vertical direction in the slab 20, and constitute the slab 20.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a connection structure and connection method for connecting a horizontal member made of reinforced concrete, such as a slab, to a steel column, and the steel column used therefor. [Background technology]

[0002] Normally, when installing a reinforced concrete slab on a steel column, a steel beam is installed on the steel column, and the reinforced concrete slab is placed on top of this steel beam. Therefore, it is usually necessary to install a steel beam between the steel column and the reinforced concrete slab. In some cases, a capital is installed on the steel column, and then the reinforced concrete slab is placed on top of it.

[0003] Furthermore, a configuration has been considered in which the slab is directly attached to a steel pipe column, eliminating the need for a capital (see, for example, Patent Document 1). In this connection structure, the ground surface is excavated and basal concrete is poured, after which a separation layer is applied on top of that, and reinforcement and concrete for the flat slab are poured on top of the separation layer, and after hardening, the bottom is excavated. In this case, multiple column anchorage bars are welded to the constructed steel column and arranged radially, multiple steel rib plates are attached to the outer periphery of the steel column, and hoop reinforcement bars surround the steel column. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-271366 Summary of the Invention [Problem to be solved by the invention]

[0005] In the technology described in Patent Document 1, in order to reliably transmit the tensile force and moment of the horizontal reinforced concrete members to the steel column, steel rib plates, radially arranged column anchoring bars, and multiple hoop bars surrounding the steel column are installed. This requires a lot of work to arrange the reinforcement. [Means for solving the problem]

[0006] The connection structure that solves the above problem is a steel column with reinforced concrete. Slabs A connection structure in which the above is connected, and is fixed to the outer periphery of the steel column, Slabs buried in , two layers spaced apart vertically a plate-shaped member; Slabs are buried at positions spaced apart in the vertical direction in the Slabs and multiple anchorage bars that transmit tension to the reinforcing bars that make up the 、 The plate-like member includes: Penetrated from top to bottom Multiple notches are formed In the notch, a fixing bar fixing member for fixing at least a part of each of the fixing bars is fitted and welded. .

[0007] In addition, the connection method that solves the above problem is to connect a steel column to a reinforced concrete column. Slabs A connection method for connecting the above. The outer periphery of the steel column is provided with: Penetrated from top to bottom Multiple notches are formed Two vertically spaced layers A plate-like member is provided, A fixing bar fixing member is welded to the notch, After the steel column is installed, Slabs At least a part of the anchoring bars is arranged at positions spaced apart in the vertical direction so that a plurality of anchoring bars that transmit tensile force to the reinforcing bars constituting the anchoring bars are arranged at positions spaced apart in the vertical direction. Each of The above Fixing bar fixing member After the reinforcing bars are placed, concrete is poured to secure the plate-like members and the anchoring bars in place. , the anchoring bar fixing member and the reinforcing bar is embedded in the concrete. Slabs Form.

[0008] Furthermore, a steel column that solves the above problem is a steel column used in a connection structure to which reinforced concrete horizontal members are connected, and has two layers of plate-like members fixed to the outer periphery and embedded in the horizontal member at positions spaced apart vertically in the horizontal member, and multiple cutouts are provided at the ends of the plate-like members at a distance, and anchorage bar fixing parts are fixed to the cutouts to transmit tensile force to the steel bars that make up the horizontal member and fix the anchorage bars embedded in the horizontal member. [Effects of the Invention]

[0009] According to the present invention, the tensile force and moment of the reinforced concrete horizontal member can be reliably transmitted to the steel column. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 2 is a schematic front view illustrating a connection structure in the first embodiment. [Figure 2] FIG. 2 is a schematic right side view illustrating a connection structure in the first embodiment. [Figure 3] FIG. 2 is a perspective view of the main part of the connection structure in the first embodiment, excluding the concrete of the slab. [Figure 4] FIG. 2 is a top view of a main part of the connection structure according to the first embodiment. [Figure 5] FIG. 2 is an enlarged top view of a main part of the steel column according to the first embodiment. [Figure 6] FIG. 2 is an enlarged perspective view of a main part of the steel column according to the first embodiment. [Figure 7] FIG. 10 is a schematic front view illustrating a connection structure in a second embodiment. [Figure 8] FIG. 10 is a schematic right side view illustrating a connection structure in the second embodiment. [Figure 9] FIG. 10 is a perspective view of the main part of the connection structure in the second embodiment, excluding the concrete of the slab. [Figure 10] FIG. 10 is a plan view of a main part of a connection structure according to a second embodiment. [Figure 11] FIG. 10 is an enlarged perspective view of a main part of a steel column according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] (First embodiment) A first embodiment of a connection structure for connecting a horizontal member made of reinforced concrete to a steel column, a connection method, and a steel column used therein will be described below with reference to Figures 1 to 6. The connection structure of this embodiment will be described as a connection structure for connecting a flat plate, which serves as a horizontal member, to a square steel pipe column, which serves as a steel column.

[0012] 1 to 4 are a front view, a right side view, a perspective view of the main part of the connection structure 10 of this embodiment excluding concrete, and a top view of the main part. Also, Fig. 5 is an enlarged top view of a corner of a plate-like member of a steel column (described later), and Fig. 6 is a perspective view of the corner of the plate-like member.

[0013] As shown in FIGS. 1 and 2, the connection structure 10 is configured by connecting a slab 20 to a square steel pipe column 11. Horizontal steel plates 15, 16 serving as plate-like members extending horizontally are welded to the outer periphery of the square steel pipe column 11. The horizontal steel plates 15, 16 are embedded in the slab 20 in two layers, one above the other, spaced apart, and are located near the top and bottom surfaces of the slab 20, respectively. In this embodiment, the horizontal steel plates 15, 16 are provided on the square steel pipe column 11 at approximately the same positions (heights) as the positions (heights) at which slab reinforcement bars are arranged in a conventional slab.

[0014] 3 and 4, the horizontal steel plates 15, 16 are configured in a frame shape with a substantially square horizontal cross section. A reinforcing plate (web) 19 is fixed to the horizontal steel plates 15, 16 so as to be perpendicular to the horizontal steel plates 15, 16. This reinforcing plate 19 is also welded to the square steel pipe column 11.

[0015] The horizontal steel plates 15, 16 are provided with through holes h1 at the corners where they meet the square steel pipe column 11 and at the abutment points between the reinforcing plates 19 and the square steel pipe column 11. These through holes h1 are used for intersecting weld beads and for filling the slab 20 with concrete 28.

[0016] 1 and 2, a plurality of spaced apart notches 15a, 16a are formed on a pair (two) of opposing sides of the horizontal steel plates 15, 16. Furthermore, a plurality of spaced apart notches 15b, 16b are formed on a pair (two) of opposing sides of the horizontal steel plates 15, 16 that are perpendicular to the sides on which the notches 15a, 16a are formed. In this embodiment, the notch 15a (15b) and the notch 16a (16b) are formed at positions where they overlap one another.

[0017] 5, the cutouts 15a to 16b have the same rectangular shape with one short side being semicircular, and the long side of the cutouts 15a to 16b has a length corresponding to the length of the mechanical joints 17a to 18b.

[0018] As shown in Figure 6, the mechanical joints 17a to 18b have a hexagonal prism-shaped outer shape and function as anchor bar fixing parts. The mechanical joints 17a to 18b are welded to the respective notches 15a to 16b via welds w1. In this case, the mechanical joints 17a to 18b are fillet welded at four locations with the horizontal surface of the hexagonal prism facing upward.

[0019] In this embodiment, as shown in Figures 1 and 2, the mechanical joints 17a, 18a are fixed at positions where their centers are above the centers (height of the center) of the horizontal steel plates 15, 16. In this case, the upper ends of the mechanical joints 17a, 18a protrude above the horizontal steel plates 15, 16, and the lower ends of the mechanical joints 17a, 18a are positioned above the lower surfaces of the horizontal steel plates 15, 16. Furthermore, the mechanical joints 17b, 18b are fixed at positions where their centers are below the centers (height of the center) of the horizontal steel plates 15, 16. In this case, the lower ends of the mechanical joints 17b, 18b protrude below the horizontal steel plates 15, 16, and the upper ends of the mechanical joints 17b, 18b are positioned below the upper surfaces of the horizontal steel plates 15, 16. As a result, the mechanical joints 17a, 17b (18a, 18b) provided in the horizontal steel plate 15 (16) in the orthogonal directions are arranged offset in the height direction.

[0020] Each of the mechanical joints 17a to 18b is disposed so as to open on the opposite side (outside) from the square steel pipe column 11. The mechanical joints 17a to 18b are, for example, internally threaded, and thereby fasten the deformed reinforcing bars in a screw-type manner.

[0021] The openings of the mechanical joints 17a, 17b, 18a, and 18b are connected to anchoring bars 31, 32, 33, and 34, respectively. In this embodiment, the notch 15a (15b) and the notch 16a (16b) are arranged in overlapping positions, so the anchoring bars 31 (32) and the anchoring bars 33 (34) are arranged in overlapping positions in the vertical direction.

[0022] In this embodiment, deformed steel bars of the same diameter are used as the anchoring steel bars 31 to 34. The diameter of these anchoring steel bars 31 to 34 is larger than the diameter of the slab steel bars 21, 22 which are the steel bars that form the slab 20. The anchoring reinforcements 31 to 34 have a length such that the outer length L1 protruding from the horizontal steel plates 15, 16 is equal to or greater than the anchoring length.

[0023] Furthermore, the slab 20 includes slab reinforcements 21 and 22 and concrete 28. The slab reinforcements 21 and 22 are arranged in contact with the horizontal steel plates 15 and 16, respectively, and function as reinforcing bars that form the horizontal members (slab 20).

[0024] Furthermore, as shown in Figure 3, the slab reinforcement bars 21, 22 are configured by arranging a plurality of main reinforcement bars extending in a first direction and a plurality of distribution reinforcement bars perpendicular to the main reinforcement bars and fixed above or below the main reinforcement bars at a distance and extending in a second direction in a grid pattern. The slab reinforcement bars 21, 22 are placed in the concrete 28 so as to correspond to the steps of the anchorage reinforcement bars 31-34. Specifically, the main reinforcement bars (or distribution reinforcement bars) extending parallel to the upper anchorage reinforcement bars 31, 33 are placed on the upper side, and the main reinforcement bars (or distribution reinforcement bars) extending parallel to the lower anchorage reinforcement bars 32, 34 are placed on the lower side. Therefore, the slab reinforcement bars 21, 22 are placed at approximately the same height as the horizontal steel plates 15, 16. In addition, the slab reinforcements 21 and 22 in this embodiment are cut off at the end of the diaphragm.

[0025] Four reinforcing bars 25 are placed in a lattice pattern on the upper surface of the horizontal steel plate 15. The reinforcing bars 25 are reinforcing bars for suppressing cracks, and are configured as rectangular thin reinforcing bars arranged in a lattice pattern. The four reinforcing bars 25 are staggered on the horizontal steel plate 15, so that the reinforcing bars are evenly distributed on the upper surface of the horizontal steel plate 15. Reinforcing bars 26 with a similar configuration to the reinforcing bars 25 are also placed on the lower surface of the horizontal steel plate 16.

[0026] 1 and 2, concrete 28 is poured while ensuring a cover thickness T1 from reinforcing bars 25 located at the top of concrete 28 and a cover thickness T2 from reinforcing bars 26 located at the bottom of concrete 28. As a result, horizontal steel plates 15, 16, mechanical joints 17a to 18b, reinforcing plate 19, slab reinforcements 21, 22, reinforcing bars 25, 26, and anchorage bars 31 to 34 are embedded in concrete 28.

[0027] (Method for constructing the connection structure 10) Next, a method for constructing the connection structure 10 having the above-described configuration will be described. First, in a factory or the like, a plurality of spaced apart notches 15a to 16b are formed on each side of the horizontal steel plates 15 and 16, and mechanical joints 17a to 18b are welded to the notches 15a to 16b, respectively. In this case, the mechanical joints 17a and 18a are welded at different heights so that their upper ends protrude above the horizontal steel plates 15 and 16, and the mechanical joints 17b and 18b are welded at different heights so that their lower ends protrude below the horizontal steel plates 15 and 16.

[0028] Then, the horizontal steel plates 15, 16 and the reinforcing plate 19 are welded to the square steel pipe column 11 at a height (position) corresponding to the mounting position of the slab 20. This forms a square steel pipe column 11 to which the horizontal steel plates 15, 16 equipped with the mechanical joints 17a to 18b are attached.

[0029] This square steel pipe column 11 is transported to the construction site. In this case, the square steel pipe column 11 may be transported in multiple pieces. Then, at the construction site, the square steel pipe column 11 is installed. The anchoring bars 31 to 34 are fixed to the square steel pipe column 11 by inserting and screwing the anchoring bars 31 to 34 into each of the mechanical joints 17a to 18b of the square steel pipe column 11.

[0030] Next, lattice-shaped slab reinforcements 21 and 22 are placed at approximately the same height as the horizontal steel plates 15 and 16. Thereafter, concrete 28 is poured using a formwork and allowed to harden, thereby forming the slab 20.

[0031] (action) In this embodiment, the anchorage reinforcements 31-34, which are thicker than the slab reinforcements 21, 22, are embedded in the concrete 28 in close proximity to the slab reinforcements 21, 22. Therefore, the adhesion force of the anchorage reinforcements 31-34 to the concrete 28 transmits the tensile force of the slab reinforcements 21, 22 to the anchorage reinforcements 31-34 via the concrete 28. Therefore, the moment M1 and shear force acting on the slab 20 can be transmitted to the square steel pipe column 11 to which the anchorage reinforcements 31-34 are fixed.

[0032] According to this embodiment, the following effects can be obtained. (1-1) In the connection structure 10 of this embodiment, anchorage bars 31-34 are fixed to horizontal steel plates 15, 16 provided on the outer periphery of a square steel pipe column 11. Then, the anchorage bars 31-34 and slab reinforcements 21, 22 are arranged near the anchorage bars 31-34 and embedded in concrete 28 to form a slab 20. This allows the tensile force of the slab reinforcements 21, 22 of the slab 20 to be transmitted to the square steel pipe column 11 via the concrete 28 and the anchorage bars 31-34. In addition, the spaced horizontal steel plates 15, 16 are arranged near the top and bottom surfaces of the slab 20. This increases the effective resistance of the anchorage bars 31-34 to the moment M1, and even when small anchorage bars 31-34 are used, cracks can be efficiently suppressed.

[0033] (1-2) In this embodiment, the mechanical joints 17a, 17b (18a, 18b) are fixed to the plurality of spaced-apart notches 15a, 15b (16a, 16b) provided in the horizontal steel plate 15 (16). This allows the center (the middle position in height) of the horizontal steel plate 15 (16) to be at approximately the same height as the centers of the anchoring reinforcements 31, 32 (33, 34) fixed to the mechanical joints 17a, 17b (18a, 18b). This suppresses the bending action due to eccentricity that occurs when bending resistance is applied in a configuration in which the horizontal steel plates 15, 16 and the anchoring reinforcements 31-34 are spaced apart, and allows the thickness of the horizontal steel plates 15, 16 to be reduced.

[0034] (1-3) In this embodiment, the anchor reinforcements 31-34 are fixed to the mechanical joints 17a, 17b (18a, 18b) that are fixed at different heights in the cutouts 15a, 15b (16a, 16b). The slab reinforcements 21, 22 are positioned according to the height difference of the anchor reinforcements 31-34, allowing the anchor reinforcements 31-34 to be positioned close to the slab reinforcements 21, 22. Therefore, the anchor reinforcements 31-34 can be positioned near the surface of the concrete 28 while ensuring the cover thicknesses T1, T2, thereby increasing the effective bending resistance. Furthermore, the anchor reinforcements 31-34 and the mechanical joints 17a, 17b (18a, 18b) that connect them can be expected to be smaller.

[0035] (1-4) In this embodiment, the anchoring bars 31-34 are fixed on-site to the mechanical joints 17a-18b that have been welded to the square steel pipe column 11 in advance at a factory. Therefore, when the square steel pipe column 11 is transported from the factory to the site, the anchoring bars 31-34 do not protrude, making it easy to handle. In addition, the amount of welding work on-site can be reduced, allowing the connection structure 10 to be constructed efficiently.

[0036] (1-5) In this embodiment, a reinforcing plate 19 is provided that extends vertically and perpendicular to the horizontal steel plates 15, 16. This allows the reinforcing plate 19 to resist shear force, thereby suppressing damage due to punching shear. Furthermore, since the reinforcing plate 19 has a size that corresponds to the spacing between the horizontal steel plates 15, 16, the cross section of the reinforcing plate 19 can be made larger. Therefore, the shear resistance provided by the reinforcing plate 19 can be increased.

[0037] (1-6) In this embodiment, the slab reinforcement 21, 22 is cut off at the ends of the horizontal steel plates 15, 16, and lattice-shaped reinforcing bars 25, 26 are placed on the upper surface of the horizontal steel plate 15 and the lower surface of the horizontal steel plate 16. This makes it possible to suppress cracks separately from the slab reinforcement 21, 22, even if there is a possibility that the crack width will increase.

[0038] (Second embodiment) Next, a second embodiment will be described with reference to Figures 7 to 11, which embodies a connection structure and connection method for connecting a horizontal member made of reinforced concrete to a steel column, and a steel column used therein. In the first embodiment, notches were provided on all four sides of the horizontal steel plate of the steel column. In this embodiment, notches are provided only on two opposing sides of the horizontal steel plate of the steel column. In this embodiment, parts similar to those in the first embodiment are given the same reference numerals, and detailed descriptions thereof will be omitted.

[0039] 7 to 10 are a front view, a right side view, a perspective view of the main part of the connection structure 50 of this embodiment excluding the concrete, and a plan view of the main part. Also, Fig. 11 is a perspective view of a corner of a plate-like member of a steel column.

[0040] 7 and 8, a connection structure 50 of this embodiment is configured by connecting a slab 70 to a square steel pipe column 51. Horizontal steel plates 55, 56 serving as plate-like members extending horizontally are welded to the outer periphery of the square steel pipe column 51. The horizontal steel plates 55, 56, like the horizontal steel plates 15, 16, are embedded in the slab 70 in two layers, one above the other, spaced apart, and are located near the top and bottom of the slab 70, respectively.

[0041] 9 and 10, the horizontal steel plates 55, 56 are configured in a frame shape with a horizontal cross section that is approximately square. A reinforcing plate (web) 19 that is also welded to the square steel pipe column 51 is fixed to the horizontal steel plates 55, 56. At the contact portion between the reinforcing plate 19 and the square steel pipe column 51, a through hole h1 is provided for processing the intersection of weld beads and filling with concrete 78.

[0042] As shown in FIG. 11, the horizontal steel plate 55 (56) has a plurality of spaced apart notches 55h (56h) formed on only one pair (two) of the four opposing sides. The notches 55h of the horizontal steel plate 55 and the notches 56h of the horizontal steel plate 56 are arranged on different sides so as not to be arranged in the vertical direction. Each notch 55h, 56h has a shape similar to the notch 15a of the first embodiment. Mechanical joints 57a, 58a are welded to the notches 55h, 56h via welds w1, respectively, as anchorage bar fixing parts.

[0043] Furthermore, a plurality of mechanical joints 57b are fixed by welding to the upper surface of the horizontal steel plate 55 on the side where no notches are formed. Each mechanical joint 57b is disposed above a corresponding mechanical joint 58a of the horizontal steel plate 56. Furthermore, a plurality of mechanical joints 58b are fixed by welding to the lower surface of the horizontal steel plate 56 on the side where no notches are formed. Each mechanical joint 58b is disposed below a corresponding mechanical joint 57a of the horizontal steel plate 55.

[0044] In this embodiment, the mechanical joints 57b, 58b secure reinforcing bars that are smaller in diameter and shorter than the mechanical joints 57a, 58a. Furthermore, each of the mechanical joints 57a to 58b is arranged with an opening on the opposite side (outside) from the square steel pipe column 51, and secures the deformed reinforcing bars by a screw method.

[0045] As shown in Figures 7 and 8, anchor bars 82, 81, 84, and 83 are connected to the openings of the mechanical joints 57a, 57b, 58a, and 58b, respectively. In this embodiment, the same deformed reinforcing bars are used as the anchor bars 81 and 83, and the same deformed reinforcing bars are used as the anchor bars 82 and 84. The anchor bars 81 and 83 are fixed to the mechanical joints 57b and 58b, which are fixed to the upper surface of the horizontal steel plate 55 or the lower surface of the horizontal steel plate 16. The anchor bars 81 and 83 have a smaller diameter than the anchor bars 82 and 84 connected to the mechanical joints 57a and 58a, but are larger in diameter than the slab reinforcements 21 and 22. Furthermore, the length L3 of the anchor bars 81 and 83 is shorter than the length L4 of the anchor bars 82 and 84. However, the outer lengths L3 and L4 of the anchor bars 81 to 84 protruding from the horizontal steel plates 55 and 56 are longer than their respective anchor lengths.

[0046] Furthermore, in the slab 70, the slab reinforcements 21, 22 are arranged in contact with the upper surface of the horizontal steel plate 15 and the lower surface of the horizontal steel plate 16, respectively. Note that, unlike the slab reinforcements 21, 22 in the above-described embodiments, the slab reinforcements 21, 22 in this embodiment are not cut off at the ends of the horizontal steel plates 55, 56.

[0047] The concrete 78 is then poured while ensuring a sufficient cover thickness from the slab reinforcements 21, 22 located at the top of the concrete 78. As a result, the horizontal steel plates 55, 56, mechanical joints 57a to 58b, reinforcing plate 19, slab reinforcements 21, 22, and anchor reinforcements 81 to 84 are embedded in the concrete 78.

[0048] (Method of constructing the connection structure 50) In the method of constructing the connection structure 50 configured as described above, as in the connection structure 10, notches 55h, 56h are formed in the horizontal steel plates 55, 56 in a factory or the like. Furthermore, mechanical joints 57a, 58a are welded to the notches 55h, 56h, respectively, a mechanical joint 57b is welded to the upper surface of the horizontal steel plate 55, and a mechanical joint 58b is welded to the lower surface of the horizontal steel plate 56. Then, by welding the horizontal steel plates 55, 56 and the reinforcing plate 19 to the square steel pipe column 51, a square steel pipe column 11 is formed to which the horizontal steel plates 55, 56 equipped with the mechanical joints 57a to 58b are attached.

[0049] Thereafter, the transported square steel pipe column 51 is installed at the site. Then, the anchoring bars 81-84 are inserted into and screwed into each of the mechanical joints 57a-58b of this square steel pipe column 51, thereby fixing the anchoring bars 81-84 to the square steel pipe column 51, and the lattice-shaped slab reinforcements 21, 22 are arranged. Thereafter, concrete 78 is poured using a formwork and allowed to harden, thereby forming the slab 70.

[0050] (action) In this embodiment, the anchoring bars 81-84, which are thicker than the slab reinforcements 21, 22, are embedded in the concrete 78 in close proximity to the slab reinforcements 21, 22. Therefore, the tensile force of the slab reinforcements 21, 22 is transmitted to the anchoring bars 81-84 via the concrete 78 due to the adhesive force of the anchoring bars 81-84 to the concrete 78.

[0051] According to this embodiment, in addition to the effects (1-1) to (1-5) above, the following effects can be obtained. (2-1) In this embodiment, the mechanical joints 57a (58a) are fixed to the notches 55h (56h) formed only on one pair of opposing sides of the horizontal steel plate 55 (56), and the mechanical joints 57b, 58b are fixed to the upper surface of the horizontal steel plate 55 or the lower surface of the horizontal steel plate 56. This allows the center (middle position in height) of the horizontal steel plate 15 (16) to be at approximately the same height as the centers of the anchoring reinforcement bars 82, 83 fixed to the mechanical joints 57a (58a). Furthermore, the heights of the anchoring reinforcement bars 81, 83 and the anchoring reinforcement bars 82, 84 can be shifted even without providing notches around the entire circumference of the horizontal steel plate 55 (56).

[0052] (2-2) In this embodiment, the mechanical joint 57b (58b) is fixed to the upper surface of the horizontal steel plate 55 (the lower surface of the horizontal steel plate 56). This allows the mechanical joint 57b (58b) to be positioned closer to the upper surface (lower surface) of the concrete 78 than the mechanical joint 57a (58a). Therefore, the anchoring bars 81 (83) connected to the mechanical joint 57b (58b) can be made of reinforcing bars with a smaller diameter and shorter length than the anchoring bars 82 (84).

[0053] This embodiment can be modified as follows: This embodiment and the following modifications can be combined and implemented within the scope of technical compatibility. In the above embodiments, the anchoring bars 31-34, 81-84 are arranged so as to be perpendicular to the horizontal steel plates 15, 16, 55, 56. The arrangement of the anchoring bars 31-34, 81-84 is not limited to being perpendicular to the horizontal steel plates 15, 16, 55, 56. For example, around the steel column, multiple anchoring bars may be arranged radially from the center of the steel column. Furthermore, the shape of the plate-like member is not limited to a rectangular frame shape, and may be a frame shape with rounded corners or a circular plate shape.

[0054] In the above embodiments, the anchor bars 31-34, 81-84 have lengths L1, L3, L4 that are greater than the anchorage length of the horizontal steel plates 15, 16, 55, 56 within the slab 20, 70. The anchor bars 31-34, 81-84 are not limited to lengths L1, L3, L4 that are greater than the anchorage length, as long as they have adhesive strength that can transmit tensile force to the slab reinforcement 21, 22. For example, if anchor plates are provided at the ends of the anchor bars 31-34, 81-84 or if the ends are bent, the anchorage length may be shorter than that of the straight anchor bars 31-34, 81-84. Furthermore, the size (thickness) and number of the anchor bars 31-34, 81-84 may be changed as appropriate.

[0055] In the above embodiments, the anchor bars 31-34, 81-84 fixed to the horizontal steel plates 15, 16, 55, 56 are arranged in overlapping positions when viewed from above. The positions and attachment methods of the anchor bars 31-34, 81-84 are not limited to this. For example, the anchor bars 31, 32, 81, 82 fixed to the horizontal steel plates 15, 55 and the anchor bars 33, 34, 83, 84 fixed to the horizontal steel plates 16, 56 may be arranged in offset positions when viewed from above. In the above embodiment, the cutouts 15a, 15b, 16a, 16b, 55h, and 56h of the horizontal steel plates 15, 16, 55, and 56 have a rectangular shape with one short side semicircular. The shape of the cutouts formed in the plate-like members is not limited to this shape, and may be any shape that allows the anchor reinforcing bar fixing portion and the anchor reinforcing bar to be fixed.

[0056] In the above embodiments, mechanical joints 17a-18b, 57a-58b are provided on the horizontal steel plates 15, 16, 55, 56 to screw-type anchor bars 31-34, 81-84, which are deformed reinforcing bars. The anchor bar fixing portion is not limited to a hexagonal screw-type mechanical joint, as long as it can fix the anchor bars to the plate-like member. For example, a cylindrical sleeve without internal threads may be used. In this case, the anchor bars placed in the hollow portion of the sleeve are fixed with grout, adhesive, or the like. Furthermore, the mechanical joints may be omitted, and the anchor bars 31-34, 81-84 may be fixed directly to the horizontal steel plates 15, 55, 16, 56 by welding or the like.

[0057] In the above embodiments, the mechanical joints 17a to 18b, 57a to 58b are welded in a position where the flat surface of the hexagonal prism is at the upper end. The position in which the mechanical joints 17a to 18b, 57a to 58b are welded is not limited to this, and for example, the mechanical joints may be welded in a position where the flat surface of the mechanical joint is approximately parallel to the side surface of the notch.

[0058] In the second embodiment, the slab reinforcement 21, 22 extends on the horizontal steel plates 55, 56, but similar to the first embodiment, the reinforcement may be cut off at the ends of the horizontal steel plates 55, 56 and the auxiliary reinforcement 25, 26 may be placed instead.

[0059] In the above embodiment, the connection structure has been described as a flat plate structure in which the square steel pipe column 11, 51 and the slab 20, 70 are directly connected. The connection structure of the present invention is not limited to flat plate structures, and may be used, for example, in flat slab structures or connection structures between steel columns and reinforced concrete beams. Here, the flat slab structure is a connection structure in which reinforcing members are provided at the connection points between the column and the slab. In these connection structures, horizontal reinforced concrete members can also be provided on the steel columns.

[0060] In the above embodiment, a case has been described in which a square steel pipe column 11 is used as a steel column. The steel column is not limited to a square steel pipe column, and may be, for example, a cylindrical round steel pipe column, or may be applied to an SRC (steel-reinforced concrete) column or a CFT (concrete-filled steel tube) column.

[0061] Furthermore, when applying this to inverted-cast supports, it is difficult to ensure accuracy by using square steel pipe columns 11, 51 to which horizontal steel plates 15, 16, 55, 56 are pre-welded. Therefore, in the case of inverted-cast supports, horizontal steel plates 15, 16, 55, 56 are installed on the outer periphery of square steel pipe columns 11, 51 at the site in accordance with the height of the slab.

[0062] Next, the technical ideas that can be understood from the above-described embodiment and other examples will be described below. (a) The connection structure described in claim 1, characterized in that the notches are provided in multiple locations on a pair of opposing sides of the plate-like member, and no notches are provided in the plate-like member in a direction perpendicular to the sides on which the notches are provided.

[0063] (b) The connection structure described in (a) is characterized in that the plate-like members are provided in two layers around the outer periphery of the steel column, and no notch is formed in the upper or lower plate-like member corresponding to the side on which the notch is provided. (c) A connection structure according to claim 1, 2, (a) or (b), characterized in that lattice-shaped reinforcing bars are arranged in the plate-like member. [Explanation of symbols]

[0064] h1...through hole, L1, L3, L4...length, M1...moment, w1...weld, 10, 50...connection structure, 11, 51...square steel pipe column, 15, 16, 55, 56...horizontal steel plate, 15a, 15b, 16a, 16b, 55h, 56h...cutout, 17a, 17b, 18a, 18b, 57a, 57b, 58a, 58b...mechanical joint, 19...reinforcement plate, 20, 70...slab, 21, 22...slab reinforcement, 25...auxiliary reinforcement, 28, 78...concrete, 31, 32, 33, 34, 81, 82, 83, 84...anchoring reinforcement.

Claims

1. A connection structure in which a reinforced concrete slab is connected to a steel column, Two layers of plate-like members fixed to the outer periphery of the steel column, embedded in the slab, and spaced apart in the vertical direction; a plurality of anchorage bars embedded in the slab at positions spaced apart in the vertical direction to transmit tensile force to the reinforcing bars that constitute the slab; The plate-like member is formed with a plurality of cutouts that penetrate vertically, A connection structure characterized in that an anchor bar fixing member that fixes at least a portion of each of the anchor bars is fitted into the cutout portion and the anchor bar fixing member is welded.

2. The plurality of anchoring bars are arranged to extend in perpendicular directions, The connection structure described in claim 1, characterized in that among the fixing bars fixed to the same plate-like member, the fixing bars arranged in perpendicular directions are arranged with a shift in the vertical direction.

3. A connection method for connecting a reinforced concrete slab to a steel column, comprising: The steel column has two layers of plate-like members on the outer periphery thereof, the plate-like members being spaced apart in the vertical direction and having a plurality of notches formed therethrough, A fixing bar fixing member is welded to the notch, After the steel column is installed, at least some of the anchoring bars are fixed to the anchoring bar fixing members so that the anchoring bars that transmit tensile force to the reinforcing bars constituting the slab are arranged at positions spaced apart in the vertical direction; A connection method characterized by forming the slab in which the plate-shaped member, the anchoring member, the anchoring member fixing member and the reinforcing bar are embedded in the concrete by pouring concrete after the reinforcing bar is placed.

4. A steel column used in a connection structure to which reinforced concrete slabs are connected, The slab has two layers of plate-like members fixed to the outer periphery and embedded in the slab at positions spaced apart in the vertical direction, a plurality of cutouts penetrating vertically are provided at a distance from one another at an end of the plate-like member; A steel column characterized in that an anchorage bar fixing member is fixed to the cutout portion, which transmits tensile force to the steel bars that make up the slab and fixes at least a portion of the anchorage bars embedded in the slab.

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