Column-beam joint construction

Abstract

To provide a column-beam joint structure that can efficiently suppress the deformation of steel pipe columns. [Solution] The column-beam joint structure 10 comprises a steel pipe column 11 made of square steel pipes and H-shaped steel beams 21, 22, 23, 24 joined to the outer surface of the steel pipe column 11. This column-beam joint structure 10 further comprises reinforcing plates 31a, 31b, 32a, 32b, 33a, 33b, 34a, 34b, whose ends are joined to the webs 21w, 22w, 23, 24 and the steel pipe column 11, respectively. The column-beam joint structure 10 comprises a space S1 surrounded by each of the reinforcing plates 31a, 31b, 32a, 32b, 33a, 33b, 34a, 34b, each of the webs 21w, 22w, 23w, 24w, and the steel pipe column 11.

Description

[Technical Field]

[0001] This disclosure relates to a column-beam joint structure comprising a steel pipe column and an H-shaped steel beam. [Background technology]

[0002] Conventionally, a column-beam joint comprising a steel pipe column and an H-shaped steel beam is known. In this column-beam joint, the upper and lower flanges of the H-shaped steel beam are generally fixed to a diaphragm provided on the steel pipe column by welding, and the web of the H-shaped steel beam is directly fixed to the steel pipe column by welding. Therefore, when bending or shear forces are applied to the H-shaped steel beam, an out-of-plane tensile force acts on the steel pipe wall (skin plate) of the steel pipe column to which the web of the H-shaped steel beam is joined, causing the steel pipe wall of the steel pipe column to deform. As a result, the maximum bending strength of the beam web may not be achieved. Therefore, a column-beam joint structure that includes reinforcing members to reinforce the H-shaped steel beam in order to suppress the deformation of the steel pipe wall of the steel pipe column has been investigated (see, for example, Patent Document 1). The column-beam joint structure described in Patent Document 1 comprises a first steel member to which a joint is provided, a second steel member to which the end of the first steel member is joined at the joint of the first steel member, and a plurality of reinforcing steel members provided on the second steel member. The first end of this reinforcing steel is joined to the joint, and the second end in the longitudinal direction is joined to the side surface of the second steel. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2016-23417 [Overview of the project] [Problems that the invention aims to solve]

[0004] However, in the column-beam joint structure described in Patent Document 1, multiple long reinforcing members are provided by welding or other means, which makes construction time-consuming. [Means for solving the problem]

[0005] A column-beam joint structure that solves the above problems comprises a steel pipe column, an H-shaped steel beam joined to the outer surface of the steel pipe column, and reinforcing members whose ends are joined to the web of the H-shaped steel beam and the steel pipe column, respectively, wherein a cross-sectional view of the column-beam joint structure includes a space enclosed by the reinforcing members, the web and the steel pipe column. [Effects of the Invention]

[0006] According to this disclosure, it is possible to reduce the effort required for construction and efficiently suppress the deformation of the steel pipe wall of the steel pipe column. [Brief explanation of the drawing]

[0007] [Figure 1] This is a perspective view of the column-beam joint structure in the embodiment. [Figure 2] This is a longitudinal cross-sectional view of the column-beam joint structure shown in Figure 1, as seen from the beam side. [Figure 3] This is a cross-sectional view taken along the line 3-3 in Figure 2. [Figure 4] This is a longitudinal cross-sectional view of the column-beam joint structure in the modified example, as seen from the beam side. [Figure 5] This is a perspective view of a column-beam joint structure using circular steel pipes in a modified example. [Figure 6] This is a cross-sectional view in the direction of line 6-6 in Figure 5. [Modes for carrying out the invention]

[0008] Hereinafter, an embodiment of the column-beam joint structure of this disclosure will be described using Figures 1 to 3. Figure 1 is a perspective view of the column-beam joint structure, Figure 2 is a cross-sectional view of the column-beam joint structure in Figure 1 as seen from the beam side, and Figure 3 is a transverse cross-sectional view in the direction of line 3-3 in Figure 2.

[0009] As shown in FIGS. 1 to 3, the column-beam joint structure 10 of this embodiment includes a steel pipe column 11, four beam members 21, 22, 23, 24 joined to the steel pipe column 11, diaphragms 13, 14, and reinforcing plates 31a, 31b, 32a, 32b, 33a, 33b, 34a, 34b as reinforcing members. Each of the beam members 21 to 24 is composed of an H-shaped steel.

[0010] The steel pipe column 11 is composed of a square steel pipe with rounded corners. Specifically, the steel pipe column 11 includes an upper square steel pipe 11a, a lower square steel pipe 11b, and an intermediate square steel pipe 11c having the same cross-section. The intermediate square steel pipe 11c is disposed between the upper square steel pipe 11a and the lower square steel pipe 11b.

[0011] A diaphragm 13 is disposed between the upper square steel pipe 11a and the intermediate square steel pipe 11c. The outer periphery of the lower end of the upper square steel pipe 11a placed on the diaphragm 13 is butt-welded to the upper surface of the diaphragm 13. The outer periphery of the upper end of the intermediate square steel pipe 11c located below the diaphragm 13 is butt-welded to contact the lower surface of the diaphragm 13. Similarly, the outer periphery of the lower end of the intermediate square steel pipe 11c and the outer periphery of the upper end of the lower square steel pipe 11b are butt-welded to the diaphragm 14.

[0012] As shown in FIG. 3, the skin plates (steel pipe walls) 11s of the intermediate square steel pipe 11c are respectively joined with the beam members 21 to 24. The beam members 21 to 24 are respectively arranged orthogonally. The square steel pipes (11a to 11c) have steel pipe wall curved surface portions R1, R2, R3, R4 each including an arc portion corresponding to the corner, and four steel pipe wall flat portions P1, P2, P3, P4 following this.

[0013] As shown in FIGS. 2 and 3, in this embodiment, the beam members 21, 22, 23, 24 have the same configuration and have upper flanges F1, lower flanges F2, and webs 21w, 22w, 23w, 24w. Each of the webs 21w to 24w is welded to the lower surface of the upper flange F1 and the upper surface of the lower flange F2 of the beam members 21 to 24. Also, the ends of the webs 21w to 24w on the side of the steel pipe column 11 are welded to the steel pipe column 11.

[0014] (Configuration of Reinforcement Plate) Next, referring to FIG. 3 again, the reinforcement plates 31a to 34b will be described in detail. The reinforcement plates 31a to 34b are plate-shaped members having a rectangular parallelepiped shape. One of the side ends of the reinforcement plates 31a and 31b is welded to each surface of the web 21w of the beam member 21, and the other side end of the reinforcement plates 31a and 31b is welded to the steel pipe wall flat part P1 of the intermediate square steel pipe 11c. The reinforcement plates 31a and 31b are joined at an angle θ1 with respect to the axial direction C1 of the beam member 21. In this embodiment, this angle θ1 is 45 degrees. Thereby, the column-beam joint structure 10 includes a space portion S1 surrounded by the reinforcement plate 31a (31b), the web 21w, and the intermediate square steel pipe 11c in a cross-sectional view.

[0015] Similarly, the reinforcement plates 32a and 32b are joined at an angle θ1 (45 degrees) to the web 22w of the beam member 22 and the end of the steel pipe wall flat part P2, respectively, thereby forming the space portion S1. The reinforcement plates 33a and 33b are joined at an angle θ1 (45 degrees) to the web 23w of the beam member 23 and the end of the steel pipe wall flat part P3, respectively, thereby forming the space portion S1. The reinforcement plates 34a and 34b are joined at an angle θ1 (45 degrees) to the web 24w of the beam member 24 and the end of the steel pipe wall flat part P4, respectively, thereby forming the space portion S1.

[0016] When constructing the above-described column-beam joint structure 10, the diaphragms 13 and 14 are fixed by butt welding above and below the intermediate square steel pipe 11c in advance at the factory. Then, the webs 21w to 24w of the beam members 21 to 24 are fixed to the respective steel pipe wall flat parts P1 to P4 of the intermediate square steel pipe 11c by fillet welding.

[0017] Thereafter, between the butt welding of the diaphragms 13 and 14 and the intermediate square steel pipe 11c, the reinforcement plates 31a to 34b are arranged, and both ends of the reinforcement plates 31a to 34b are butt welded to the webs 21w to 24w and the intermediate square steel pipe 11c, respectively. Subsequently, the intermediate rectangular steel pipe 11c, to which the diaphragms 13 and 14, beam members 21 to 24, and reinforcing plates 31a to 34b are attached, is butt-welded to the lower rectangular steel pipe 11a. Furthermore, the lower rectangular steel pipe 11b is butt-welded to the lower rectangular steel pipe 11b.

[0018] (Effect of the embodiment) Since the reinforcing plates 31a to 34b are welded and fixed to the intermediate rectangular steel pipe 11c and the beam members 21 to 24, the force applied to the webs 21w to 24w of the beam members 21 to 24 is transmitted to the intermediate rectangular steel pipe 11c via the reinforcing plates 31a to 34b.

[0019] (Effects of the embodiment) (1) In this embodiment, both ends of the plate-shaped reinforcing plates 31a to 34b are welded to the ends of the flat sections P1 to P4 of the steel pipe wall of the intermediate rectangular steel pipe 11c and to the respective webs 21w to 24w of the beam members 21 to 24. As a result, the force applied to the webs 21w to 24w is distributed and transmitted to the intermediate rectangular steel pipe 11c via the reinforcing plates 31a to 34b, thereby suppressing deformation of the skin plate 11s of the intermediate rectangular steel pipe 11c. Furthermore, since only the side surfaces of the reinforcing plates 31a to 34b are welded, the burden during construction is reduced, and workability can be improved.

[0020] (2) In this embodiment, plate-shaped reinforcing plates 31a to 34b are arranged at a 45-degree angle to the webs 21w to 24w and the flat sections P1 to P4 of the steel pipe walls of the intermediate rectangular steel pipes 11c. This allows forces from the beam members 21 to 24 to be efficiently transmitted to the steel pipe columns 11 via the reinforcing plates 31a to 34b.

[0021] This embodiment can be implemented with the following modifications. This embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically. In the above embodiment, reinforcing plates 31a to 34b are provided on both sides of the webs 21w to 24w of each beam member 21 to 24. The reinforcing plates 31a to 34b do not necessarily need to be provided on both the left and right sides with respect to the extending direction of the webs 21w to 24w of each beam member 21 to 24; they may be provided on only one side.

[0022] In the above embodiment, reinforcing plates 31a to 34b are provided extending between the welded portion on the lower surface of the upper flange F1 and the welded portion on the upper surface of the lower flange F2 of each beam member 21 to 24. However, the number of reinforcing plates 31a to 34b and the positions in which they are provided are not limited, and for example, multiple reinforcing plates may be provided in the vertical direction of the steel pipe column 11.

[0023] Specifically, for example, as shown in the column-beam joint structure 40 in Figure 4, four reinforcing plates 36a, 36b, 37a, and 37b may be provided on both the left and right sides with respect to the extending direction of the web 22w and in the vertical direction of the steel pipe column 11. Here, the centers of the reinforcing plates 36a and 36b in the extending direction of the steel pipe column 11 are located from the lower surface of the upper flange F1 to the effective length h of the beam web. m It is installed at position c5 (height) which is a few minutes below. Also, the reinforcing plates 37a and 37b are positioned so that their centers are within the effective length h of the beam web from the upper surface of the lower flange F2. m It is installed at position c6 (height), which is one minute above.

[0024] Here, the effective length h of the beam web. m This is the position where the out-of-plane deformation of the skin plate 11s of the intermediate rectangular steel pipe 11c is maximum. Specifically, the effective length h of the beam web. m As described in the Design Guidelines for Steel Structure Joints (2006 revision), this is the intersection of the yield lines of the steel pipe column 11 wall, and in the case of a square steel pipe, it is represented by the following formula (1).

[0025]

number

[0026] In equation (1), b j The width of the yield region of the square steel pipe (11c) wall, t bw The thickness of the web 22w of the beam member 22 is t cf is the plate thickness of the square steel pipe (11c) wall, Fcy is the yield strength of the steel pipe column 11, and Fwy is the yield strength of the beam web.

[0027] However, the effective length h of the web 22w m is less than the beam-seismic direction length Sr of the cross-sectional defect at the beam web joint (h m < Sr), the effective length h of the web 22w m is the same as the beam-seismic direction length of the cross-sectional defect at the beam web joint (h m = Sr). In this case, in the steel pipe column 11 which is a square steel pipe, when h m > d j / 2 or b j ·t bw ·Fwy / (t cf 2 ·Fcy) ≤ 4, h m = d j / 2. Here, d j is the height of the plastic region of the steel pipe column 11 wall and is the inner distance between the diaphragms 13, 14. Also, the reinforcing plates 36a, 36b, 37a, 37b may be provided only on one side of the web 22w, or the reinforcing plates 36a, 37b (36b, 37a) at an oblique position may be provided.

[0028] ·In the above embodiment, a square steel pipe was used as the steel pipe column 11 of the column-beam joint structure 10. The steel pipe column of the column-beam joint structure 10 is not limited to a square steel pipe and may be a circular steel pipe. For example, as shown in FIGS. 5 and 6, in the column-beam joint structure 50, H-shaped steel beams 55, 56 are joined to a circular steel pipe 51 via diaphragms 53, 54. And this column-beam joint structure 50 includes reinforcing plates 58a, 58b, 59a, 59b. Both ends of the reinforcing plates 58a, 58b are joined to the web 55w of the H-shaped steel beam 55 and the steel pipe wall of the circular steel pipe 51 by welding, respectively. Both ends of the reinforcing plates 59a, 59b are joined to the web 56w of the H-shaped steel beam 56 and the steel pipe wall of the circular steel pipe 51 by welding, respectively. Thereby, the column-beam joint structure 50 includes a space portion S2 surrounded by each of the reinforcing plates 58a, 58b, 59a, 59b, each of the webs 55w, 56w, and the steel pipe wall of the circular steel pipe 51. In this case, the reinforcing plates 58a, 58b (59a, 59b) may be provided at an angle of θ1 (45 degrees) with respect to the webs 55w (56w), respectively. Furthermore, in Figure 6, the reinforcing plates 58a to 59b are welded to the circular steel pipe 51 such that their inner surfaces abut against the outer circumference of the circular steel pipe 51. The welding position relative to the circular steel pipe 51 is not limited to this, and welding may be performed at an even closer position. For example, as shown by the dashed line in Figure 6, the reinforcing plate 60 may be provided at a position where its outer surface lies on the line 61 that abuts against the inner circumference of the circular steel pipe 51.

[0029] In the above embodiment, reinforcing plates 31a to 34b are provided at an angle of θ1 with respect to the web 55w (56w) and the skin plate 11s of the square steel pipe. This angle θ1 may be an angle other than 45 degrees. In the column-beam joint structure 10 of the above embodiment, the ends of the reinforcing plates 31a to 34b are welded to the ends of the flat sections P1 to P4 of the steel pipe wall of the intermediate rectangular steel pipe 11c of the steel pipe column 11. The position where the reinforcing plates 31a to 34b are joined to the steel pipe column 11 is such that the force transmitted to the reinforcing plates 31a to 34b is efficiently transmitted to the curved sections R1 to R4 of the steel pipe wall of the steel pipe column 11. For example, the reinforcing plates may be positioned close to the tangent to the curved section of the steel pipe wall of the steel pipe column, and two reinforcing plates may be positioned on either side of the curved section of the steel pipe wall. In the above embodiment, plate-shaped reinforcing plates 31a to 34b were used as reinforcing members. The shape of the reinforcing members is not limited to a plate shape, and may be a plate with a curved surface. Furthermore, angle steel or channel steel may be used as reinforcing members, or rod-shaped reinforcing members may be used.

[0030] In the above embodiment, the beam members 21 to 24 of the column-beam joint structure 10 were made of H-shaped steel assembled by welding the webs 21w to 24w to the upper flange F1 and the lower flange F2. The beam members 21 to 24 are not limited to H-shaped steel of this configuration, but may also be made of H-shaped steel formed by rolling together the web and flange using general roll material. In this case, the web of the beam member may be joined to the steel pipe column 11 using bolts. In the above embodiment, each reinforcing plate 31a to 34b was joined by butt welding. The welding method for joining the reinforcing plates is not limited as long as the required load-bearing capacity is ensured, and may be, for example, fillet welding.

[0031] Next, the technical concepts that can be understood from the above embodiments and alternative examples are described below. (a) The column-beam joint structure according to claim 3, characterized in that the reinforcing member is positioned at a location that is below the lower surface of the upper flange by the effective length of the beam web, which is the intersection of the yield lines of the steel pipe wall, or at a location that is above the upper surface of the lower flange by the effective length of the beam web. (b) The column-beam joint structure according to claim 2, 3, or (a), characterized in that the reinforcing member is arranged at a 45-degree angle to the web and the steel pipe column. (c) The column-beam joint structure according to claim 1, characterized in that the steel pipe column is a circular steel pipe. [Explanation of symbols]

[0032] θ1...Angle, C1...Axis direction, c5, c6...Position, F1...Top flange, F2...Bottom flange, P1, P2, P3, P4...Steel pipe wall flat part, R1, R2, R3, R4...Steel pipe wall curved part, S 1,S2...Space, 10,40,50...Column beam joint structure, 11...Steel pipe column, 11a...Upper square steel pipe, 11b...Lower square steel pipe, 11c...Middle square steel pipe, 11s...Skin plate (steel pipe) Walls), 13, 14, 53, 54... diaphragms, 21, 22, 23, 24... beam members, 21w, 22w, 23w, 24w, 55w, 56w... webs, 31a, 31b, 32a, 32b, 33a, 33b, 34a, 34b, 36a, 36b, 37a, 37b, 58a, 58b, 59a, 59b... reinforcing plates (reinforcing members), 51... circular steel pipes, 55, 56... H-shaped steel beams.

Claims

1. Steel pipe columns and An H-shaped steel beam joined to the outer surface of the steel pipe column, A column-beam joint structure comprising a reinforcing member whose ends are joined to the web of the H-shaped steel beam and the steel pipe column, respectively, A column-beam joint structure characterized in that, in a cross-sectional view of the column-beam joint structure, it comprises a space enclosed by the reinforcing member, the web, and the steel pipe column.

2. The aforementioned steel pipe column is a square steel pipe, The column-beam joint structure according to claim 1, characterized in that one end of the reinforcing member is connected to the steel pipe wall of the square steel pipe.

3. The column-beam joint structure according to claim 1 or 2, characterized in that a plurality of reinforcing members are provided in the extending direction of the steel pipe column.

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