Joint structure

Abstract

To provide a joint structure or the like that can firmly join RC shear walls to steel frames.SOLUTION: A joint structure 10 joins a frame 2 having steel-framed columns 21 and beams 22 to an RC shear wall 1 installed within the structural plane of the frame 2. An opening 3 is provided in the RC shear wall 1, and perforated steel plates 23 are provided on the RC shear wall 1 side of the columns 21 and the beams 22. Reinforcement bars 12 are embedded in the RC shear wall 1 along the edge of the opening 3. In the joint structure 10, stress is transmitted in the axial direction of the reinforcing bars 12 between one end of the reinforcing bars 12 and the perforated steel plates 23 via concrete of the RC shear wall 1, thereby fixing the RC shear wall 1 to the columns 21 and the beams 22.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a joint structure between a shear wall having an opening and a frame. [Background technology]

[0002] In a structure with a frame made of RC (reinforced concrete) or SRC (steel-reinforced concrete) columns and beams, a reinforced concrete earthquake-resistant wall (hereinafter referred to as an RC earthquake-resistant wall) may be installed within the structural surface of the frame.

[0003] When an opening is provided in an RC shear wall, opening reinforcement bars are embedded in the concrete of the RC shear wall to prevent cracks at the opening edges (see, for example, Patent Document 1). If the opening is located close to a column or beam of the frame, the ends of the opening reinforcement bars can be fixed to the column or beam of the frame to firmly join the RC shear wall to the frame, preventing the RC shear wall from lifting up from the frame. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2016-142021 Summary of the Invention [Problem to be solved by the invention]

[0005] When the frame is made of steel, it is difficult to secure the opening reinforcement bars to the steel beams and columns of the frame, so there was a need for a method that could firmly connect the RC earthquake-resistant wall to the frame in such cases and prevent the RC earthquake-resistant wall from lifting up from the frame.

[0006] The present invention has been made in view of the above problems, and aims to provide a joint structure etc. that can firmly join an RC earthquake-resistant wall to a steel frame. [Means for solving the problem]

[0007] This joint structure is between a frame having at least steel-framed columns or beams and a reinforced concrete earthquake-resistant wall that is arranged within the structural surface of the frame so as to be surrounded by the frame, wherein an opening is provided in the earthquake-resistant wall, a perforated steel plate is attached to the earthquake-resistant wall side of the steel-framed columns or beams, reinforcing bars are embedded in the earthquake-resistant wall along the edge of the opening or along the steel bars that are arranged along the edge of the opening to prevent cracking of the opening edge, and the earthquake-resistant wall is fixed to the steel-framed columns or beams by transmitting stress in the axial direction of the reinforcing bars between one end of the reinforcing bars and the perforated steel plate via the concrete of the earthquake-resistant wall.

[0008] In this invention, as described above, a steel frame is connected to an RC shear wall within its structural surface using reinforcing bars and perforated steel plates along the edges of openings in the RC shear wall, and stress is transmitted between the reinforcing bars and the perforated steel plates in the axial direction of the reinforcing bars via the concrete of the RC shear wall. This fixes the RC shear wall to the frame, and prevents the RC shear wall from lifting up from the frame, even in steel frames where opening reinforcing bars cannot be fixed as described above.

[0009] It is desirable that the perforated steel plate be arranged with its plate surface facing in-plane to the structural surface, that penetrating reinforcement bars be passed through the holes in the perforated steel plate, and that one end of the reinforcing bar have a hook that is arranged so as to cover the penetrating reinforcement from the column or beam side of the steel frame. It is also desirable that the reinforcing bar be arranged so that the hook comes into contact with the column or beam of the steel frame. The reinforcing bars have hooks on one end, and by placing these hooks from the frame side over the penetrating bars that have passed through the holes in the perforated steel plate, stress can be transmitted between the reinforcing bars and the perforated steel plate via the concrete of the RC shear wall and the penetrating bars. In addition, by placing the hooks so that they are in contact with the frame, installation of the reinforcing bars becomes easier.

[0010] It is also preferable that a hook is provided at one end of the reinforcing bar, and that the reinforcing bar is placed through a hole in the perforated steel plate. In this case, stress can be transmitted between the hook and the perforated steel plate through the concrete of the RC shear wall.

[0011] For example, steel bars for preventing cracks at the opening edge are embedded in the earthquake-resistant wall along the opening edge, and the reinforcing bars are provided separately from the steel bars. Steel bars (opening reinforcement bars) are buried near the opening to prevent cracks at the edges of the opening, but these reinforcement bars can be placed separately from the steel bars, allowing for optimal placement according to the function of each steel bar.

[0012] The opening is provided, for example, near a column or beam of the steel frame structure. The opening is provided, for example, near the frame, and the fastening of the RC shear wall to the frame is weakened near the opening. The joint structure of the present invention can compensate for the weakening of the fastening between the shear wall and the frame caused by such an opening, and firmly join the RC shear wall to the frame. [Effects of the Invention]

[0013] The present invention can provide a joint structure that can firmly join an RC earthquake-resistant wall to a steel frame. [Brief explanation of the drawings]

[0014] [Figure 1] Diagram showing RC shear wall 1. [Figure 2] 1 is a diagram showing a joint structure 10. FIG. [Figure 3] Hook 123 example. [Figure 4] An example in which multiple perforated steel plates 23 are arranged. [Figure 5] An example in which the reinforcing bar 12 is passed through the holes 231 of the perforated steel plates 23, 23a. [Figure 6] Example of opening 3. [Figure 7] An example of a connection between an RC shear wall 1 and a frame 2 using reinforcing bars 12 and perforated steel plates 23. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

[0016] 1 is a front view of an RC shear wall 1 having a joint structure 10 according to an embodiment of the present invention. The RC shear wall 1 is a reinforced concrete shear wall, and is installed within the structural plane of a frame 2 having a square-shaped elevation and made up of steel-framed columns 21 and beams 22.

[0017] In this embodiment, the columns 21 are concrete-filled steel pipe columns (CFT columns) in which concrete is filled inside a steel pipe, and shaped steel such as H-shaped steel is used for the beams 22. In this way, steel frame construction includes not only the use of shaped steel such as H-shaped steel as structural members, but also the use of concrete-filled steel pipe columns as the columns 21.

[0018] Perforated steel plates 23 for joining the RC shear wall 1 are provided on the surfaces of the columns 21 and beams 22 of the frame 2 facing the RC shear wall 1. The perforated steel plates 23 are arranged along the axial direction of the columns 21 and beams 22, with their plate surfaces oriented in the in-plane direction of the structural face of the frame 2. Concrete for the RC shear wall 1 is filled into the holes 231 of the perforated steel plates 23, so that stress is transmitted between the RC shear wall 1 and the frame 2 via the perforated steel plates 23.

[0019] In addition, a small gap is provided between the RC earthquake-resistant wall 1 and the upper beam 22 of the frame 2, and this gap is filled with a filler 24 such as non-shrink mortar. However, this is not limited to this, and there may be no gap between the RC earthquake-resistant wall 1 and the upper beam 22 into which the filler 24 can be filled.

[0020] The RC shear wall 1 has an opening 3 near the frame 2. In particular, in this embodiment, the opening 3 is provided at the lower left corner of the RC shear wall 1 so as to contact the left-side column 21 and the lower beam 22. The opening 3 in this embodiment is provided for people to enter and exit.

[0021] Near the opening 3, opening reinforcement bars 11 are embedded in the concrete of the RC shear wall 1. The opening reinforcement bars 11 are reinforcing bars for preventing cracks at the edge of the opening, and are arranged along the edge of the opening 3.

[0022] In the example of Figure 1, the elevation of the opening 3 is rectangular, and the opening reinforcement 11 includes horizontal cross bars 111 arranged along the top edge of the opening 3, vertical longitudinal bars 112 arranged along the right edge of the opening 3, and diagonal bars 113 arranged on the upper right side of the opening 3.

[0023] The horizontal reinforcement 111 is arranged so as to extend from near the left-side column 21 to the right outer side of the opening 3. The vertical reinforcement 112 is arranged so as to extend from the middle of the height direction of the right side of the opening 3 to near the upper beam 22. The diagonal reinforcement 113 is arranged so as to be inclined at an angle of approximately 45° with respect to the horizontal and vertical directions. The horizontal reinforcement 111, vertical reinforcement 112, and diagonal reinforcement 113 are arranged so as to ensure the required anchorage length from the expected crack position. However, the arrangement of the horizontal reinforcement 111, vertical reinforcement 112, and diagonal reinforcement 113 is not limited to this.

[0024] In this embodiment, reinforcing bars 12, separate from the opening reinforcing bars 11, are embedded in the concrete of the RC shear wall 1 near the opening 3. The reinforcing bars 12 are steel bars for fixing the RC shear wall 1 to the frame 2, and are arranged along the edge of the opening 3.

[0025] The reinforcing bars 12 include horizontal reinforcing bars 121 arranged along the upper edge of the opening 3 and vertical reinforcing bars 122 arranged along the right edge of the opening 3. The horizontal reinforcing bars 121 are arranged so as to extend from the right outer side of the opening 3 to the vicinity of the column 21 on the left side. The vertical reinforcing bars 122 are arranged so as to extend from the middle of the height direction of the right edge of the opening 3 to the vicinity of the beam 22 below. The horizontal reinforcing bars 121 and vertical reinforcing bars 122 are arranged so as to ensure the required anchorage length.

[0026] The joint structure 10 of this embodiment is configured to include the above-mentioned reinforcing bars 12 and perforated steel plates 23. Fig. 2(a) is a diagram showing the joint structure 10 including the vertical reinforcing bars 12 (122), and shows an elevation view of the internal structure of the RC shear wall 1 near the reinforcing bars 12. Fig. 2(b) shows a horizontal cross section taken along line AA in Fig. 2(a).

[0027] As shown in Figures 2(a) and (b), through-hole reinforcement 232 passes through holes 231 in perforated steel plate 23. The through-hole reinforcement 232 is a reinforcing bar in the out-of-plane direction of the structural surface of frame 2, and both ends thereof protrude from perforated steel plate 23. The out-of-plane direction corresponds to the normal direction to the paper surface in Figure 2(a) and the up-and-down direction in Figure 2(b).

[0028] The reinforcing bar 12 has a hook 123 at one end on the beam 22 side. The hook 123 is formed by folding the reinforcing bar 12 back 180 degrees and is positioned so that it covers the protruding portion of the penetrating bar 232 from the perforated steel plate 23 from the beam 22 side. The hook 123 faces away from the opening 3 (the right side in the example of Figure 2(a)), and the main body of the reinforcing bar 12, excluding the hook 123, is positioned as close to the opening 3 as possible. The diameter of the hook 123 shall be equal to or greater than the minimum value shown in Table 4.1 "Bending Shape and Dimensions of Reinforcing Bars" in "Guidelines and Commentary for Reinforcement Arrangement in Reinforced Concrete Structures, 6th Edition," edited by the Architectural Institute of Japan, p. 112, 2021.

[0029] In this embodiment, stress can be transmitted between the hook 123 of the reinforcing bar 12 and the perforated steel plate 23 in the axial direction of the reinforcing bar 12 (vertical direction in the example of Figure 2(a)) via the concrete of the RC seismic wall 1 and the penetrating bar 232, thereby fixing the RC seismic wall 1 to the beam 22.

[0030] In this embodiment, two reinforcing bars 12 are provided, and the hooks 123 of these reinforcing bars 12 are arranged so as to cover, from the beam 22 side, the through bars 232 that have passed through separate holes 231 in the perforated steel plate 23. These hooks 123 are arranged on both the front and back sides of the perforated steel plate 23, respectively, but this is not limited thereto and they may also be arranged on the same side of the perforated steel plate 23. In addition, the lower end of each hook 123 contacts the beam 22.

[0031] The above has been an explanation of the vertical reinforcement 12 (122), but the horizontal reinforcement 12 (121) also has the above-mentioned hook 123 at one end on the column 21 side, and is installed in the same manner as above to the penetrating reinforcement 232 passed through the perforated steel plate 23 of the column 21. This makes it possible to transmit stress in the axial direction (horizontal direction) of the reinforcement 12 between the hook 123 of the reinforcement 12 and the perforated steel plate 23 via the concrete of the RC earthquake wall 1 and the penetrating reinforcement 232, and the RC earthquake wall 1 is fixed to the column 21.

[0032] In the figure, reference numerals 13 and 14 denote wall reinforcement bars inside the RC shear wall 1, which are arranged in a grid pattern vertically and horizontally on both sides of the thickness of the RC shear wall 1. The penetrating reinforcement bars 232 are arranged so as to fit between the wall reinforcement bars 13 and 14 on both sides of the thickness of the RC shear wall 1, so as not to penetrate into the cover thickness of the wall reinforcement bars 13 and 14. Reference numeral 15 denotes a U-shaped cover reinforcement bar arranged near the opening 3, which is arranged with its back to the opening 3 so as to connect the ends of the wall reinforcement bars 14 (horizontal reinforcing bars) on both sides of the thickness of the RC shear wall 1 on the opening 3 side. In this example, the wall reinforcement bars 13 and 14 are double-reinforced, but single-reinforced reinforcement is also possible depending on the wall thickness of the RC shear wall 1.

[0033] As explained above, in this embodiment, the steel frame 2 is connected to the RC shear wall 1 within its structural surface using the reinforcing bars 12 and the perforated steel plate 23 along the edge of the opening in the RC shear wall 1, and stress is transmitted in the axial direction of the reinforcing bars 12 between the reinforcing bars 12 and the perforated steel plate 23 via the concrete of the RC shear wall 1. This fixes the RC shear wall 1 to the frame 2, and prevents the RC shear wall 1 from lifting up from the frame 2, even in the case of a steel frame 2.

[0034] In particular, in this embodiment, by arranging the hook 123 at one end of the reinforcing bar 12 so that it covers the penetrating bar 232 passed through the hole 231 of the perforated steel plate 23 from the frame 2 side, stress can be transmitted between the reinforcing bar 12 and the perforated steel plate 23 via the concrete of the RC seismic wall 1 and the penetrating bar 232.

[0035] In addition, opening reinforcement bars 11 are buried near the opening 3 of the RC earthquake-resistant wall 1 to prevent cracks at the edge of the opening, but the reinforcement bars 12 in this embodiment can be placed separately from the opening reinforcement bars 11, allowing for optimal placement according to the function of each steel bar.

[0036] In this embodiment, the opening 3 is provided near the frame 2, and the fixing of the RC shear wall 1 to the frame 2 is weakened near the opening 3. The joint structure 10 compensates for the weakening of the fixing between the RC shear wall 1 and the frame 2 caused by the opening 3, and can firmly join the RC shear wall 1 to the frame 2.

[0037] However, the present invention is not limited to the above embodiment. For example, the hook 123 of the reinforcing bar 12 is formed by folding back the end of the reinforcing bar 12 by 180 degrees, but this is not limited thereto. The end of the reinforcing bar 12 may be folded back by 135 degrees as shown in Fig. 3(a) or by 90 degrees as shown in Fig. 3(b). In addition, in this embodiment, the hook 123 faces away from the opening 3, but this is not limited thereto. The hook 123 may face closer to the opening 3.

[0038] In this embodiment, the hooks 123 of the reinforcing bars 12 are arranged so as to contact the columns 21 and beams 22 of the frame 2, but as shown in Figure 3(c), it is also possible to arrange the hooks 123 at a predetermined gap from the frame 2 by tying them to the through-bars 232. However, it is easier to install the reinforcing bars 12 when the hooks 123 are arranged so as to contact the frame 2.

[0039] In addition, although the through reinforcement 232 in this embodiment is straight, it is also possible to make one end into a hook shape by bending it in a direction away from the frame 2, or to make both ends into a U shape by bending it in a direction away from the frame 2.

[0040] In this embodiment, as shown in Figure 2(b), only one perforated steel plate 23 is arranged in the center of the width direction of the beam 22 (corresponding to the out-of-plane direction mentioned above; hereinafter referred to as the beam width direction), but multiple perforated steel plates 23 may be arranged at intervals in the beam width direction, as shown in Figure 4, a cross section similar to Figure 2(b).

[0041] In the example of FIG. 4 , one penetrating reinforcement 232 is arranged in the beam width direction so as to penetrate through the holes 231 of the two perforated steel plates 23. Reinforcing bars 12 (122) are also arranged at intervals in the beam width direction, and the hooks 123 of these reinforcing bars 12 are arranged inside the two perforated steel plates 23, along the opposing surfaces of each of the perforated steel plates 23. However, this is not limited to this, and the hooks 123 may also be arranged outside the two perforated steel plates 23. The above also applies to the columns 21 of the frame 2.

[0042] In this embodiment, the hooks 123 of the reinforcing bars 12 are arranged so as to cover the penetrating reinforcing bars 232 that have passed through the holes 231 of the perforated steel plate 23. However, as shown in FIG. 5( a), the hooks 123 of the reinforcing bars 12 may also be passed through the holes 231 of the perforated steel plate 23. In this case, stress is transmitted in the axial direction of the reinforcing bars 12 between the hooks 123 of the reinforcing bars 12 and the perforated steel plate 23 via the concrete of the RC shear wall 1 that has been filled in the holes 231. However, it is somewhat difficult to fix the reinforcing bars 12 with the hooks 123 passed through the holes 231, and therefore, from the viewpoint of construction, it is preferable to configure the hooks 123 to cover the penetrating reinforcing bars 232 as described above.

[0043] Alternatively, as shown in Figure 5(b), the perforated steel plate 23a may be T-shaped, and the reinforcing bar 12 may be passed partway through a hole 231 provided in the flange of the perforated steel plate 23. In this case as well, stress is transmitted in the axial direction of the reinforcing bar 12 via the concrete of the RC shear wall 1 between the hook 123 of the reinforcing bar 12 and the flange of the perforated steel plate 23.

[0044] In addition, in this embodiment, the reinforcing bars 12 are provided separately from the opening reinforcing bars 11, but by providing hooks similar to the above-mentioned hooks 123 at the ends of the opening reinforcing bars 11 (horizontal bars 111 and vertical bars 112) on the frame 2 side, the opening reinforcing bars 11 can also be used as reinforcing bars 12 for joining the RC earthquake-resistant wall 1 and the frame 2.

[0045] In addition, in the frame 2 of this embodiment, both the columns 21 and the beams 22 are made of steel, but one of the columns 21 and the beams 22 may be made of steel. In this case, the connection structure 10 using the reinforcing bars 12 and the perforated steel plates 23 is applied to the steel-framed columns 21 or beams 22. For example, when the columns 21 are made of reinforced concrete or steel reinforced concrete, the connection structure 10 is applied to the steel-framed beams 22.

[0046] The joint structure 10 of this embodiment can be applied when constructing a new RC shear wall 1 and a frame 2, but can also be applied when constructing a new RC shear wall 1 for an existing frame 2. In this case, a perforated steel plate 23 is newly installed for the existing frame 2.

[0047] Furthermore, although the opening 3 in this embodiment is for people to pass through, as shown in Figure 6, even if there is a relatively small opening 3 near the frame 2 for passing equipment piping, etc., the RC earthquake-resistant wall 1 can be fixed to the frame 2 using the joint structure 10.

[0048] Furthermore, as shown in Figure 7(a), even if the opening 3 itself is not in contact with the frame 2, the RC earthquake-resistant wall 1 and the frame 2 can be firmly joined by applying a joint structure 10 using reinforcing bars 12 arranged along the edge of the opening and perforated steel plates 23.

[0049] Additionally, in this embodiment, a portion of the perforated steel plate 23 close to the opening 3 is used for the connection structure 10, but there are also cases where a portion away from the opening 3 is used for the connection structure 10. For example, in FIG. 7(b), when the opening 3 is provided so as to contact the lower beam 22, the upper beam 22 is also connected by the connection structure 10 using the reinforcing bars 12 arranged along the opening reinforcing bars 11 (112) and the perforated steel plate 23. As shown in FIG. 7(b), even in a portion away from the opening 3, if necessary, the RC shear wall 1 is fixed to the frame 2 by the reinforcing bars 12 and the perforated steel plate 23, and the reinforcing bars 12 may be arranged along the opening reinforcing bars 11 rather than at the opening edge.

[0050] While the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to these examples. It is clear that those skilled in the art can conceive of various modifications or alterations within the scope of the technical ideas disclosed herein, and it is understood that these modifications also fall within the technical scope of the present invention. [Explanation of symbols]

[0051] 1: RC earthquake-resistant wall 2: Frame 3: Opening 10:Joint structure 11: Opening reinforcement 12, 121, 122: Reinforcement bars 21: Pillar 22: Beam 23, 23a: Perforated steel plate 111: Horizontal stripes 112: Vertical stripes 113: Oblique muscles 123: Hook 231: Hole 232: Penetrating muscle

Claims

1. A joint structure between a frame having at least steel columns or beams and a reinforced concrete earthquake-resistant wall arranged within the structural surface of the frame so as to be surrounded by the frame, An opening is provided in the seismic wall, A perforated steel plate is provided on the seismic wall side of the steel-framed column or beam, Reinforcement bars are embedded in the seismic wall along the edge of the opening or along the reinforcing bars arranged along the edge of the opening to prevent cracks at the edge of the opening, A joint structure characterized in that the earthquake-resistant wall is fixed to the steel-framed column or beam by transmitting stress in the axial direction of the reinforcing bar between one end of the reinforcing bar and the perforated steel plate through the concrete of the earthquake-resistant wall.

2. The perforated steel plate is arranged with its plate surface in the in-plane direction of the structural surface, A through-hole reinforcement is passed through the hole of the perforated steel plate, 2. A joint structure according to claim 1, wherein one end of the reinforcing bar has a hook that is positioned so as to cover the penetrating bar from the column or beam side of the steel structure.

3. A hook is provided at one end of the reinforcing bar, 2. The joint structure according to claim 1, wherein the reinforcing bars are arranged through holes in the perforated steel plate.

4. Reinforcement bars for preventing cracks at the opening edge are embedded in the earthquake-resistant wall along the opening edge of the opening, 2. The joint structure according to claim 1, wherein the reinforcing bars are provided separately from the reinforcing bars.

5. 3. The joint structure according to claim 2, wherein the reinforcing bar is arranged so that the hook contacts the column or beam of the steel frame structure.

6. The joint structure according to claim 1, wherein the opening is provided near a column or beam of the steel frame structure.

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