Column-beam joint structure

Abstract

To provide a column-to-beam joint structure in a non-diaphragm type frame having a rigidity equivalent to that of a through-diaphragm type frame or an inner-diaphragm type frame.SOLUTION: A column-to-beam joint structure 10 includes column shafts 11A and 11B, a beam 13, a connection core 12, and a horizontal haunch 31. The connection core 12 is formed such that a relation between a plate thickness tp of the connection core 12 and an outer diameter Bc of the column shafts 11A and 11B is tp≥(Bc / 10)+5, and that a relation between an extra length e of an extra length portion 15 of the connection core 12 and the outer diameter Bc of the column shafts 11A and 11B is e≥Bc / 4. The horizontal haunch 31 is formed such that a relation between a widthwise length W of the horizontal haunch 31 and a widthwise length W1 of a flat plate portion 12s of the connection core 12 is W≥W1, and that a relation between a length L of the horizontal haunch 31 in the longitudinal direction, the outer diameter Bc of the column shafts 11A and 11B, and a widthwise length W2 of a flange 13a is L≥Bc-W2.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a column-beam connection structure comprising a column section made of a square steel pipe, a beam section made of an H-shaped steel, and a non-diaphragm type joint section made of a square steel pipe that serves as the connection between the column section and the beam section. [Background technology]

[0002] Conventionally, this type of beam-column joint structure has been constructed by welding together a number of steel pipes, and the welding connections used in this case include, for example, a through diaphragm type, an inner diaphragm type, and the like. However, these joining methods such as the through diaphragm type and the inner diaphragm type require many assembly steps (welding points) and the weld length is long, which makes the overall work complicated. In addition, these joining methods have the problem that the diaphragm installed inside the column cannot be visually observed from the outside of the column, making it impossible to check whether the diaphragm is installed properly inside the column.

[0003] To solve these problems, a non-diaphragm type column-beam joint structure has been proposed that uses thick short rectangular steel pipes formed by hot forming in the joints that connect the column and beam (for example, Patent Document 1). This column-beam joint structure that uses thick short rectangular steel pipes obtained by hot forming can reduce the assembly man-hours and shorten the welding length, simplifying the overall work. In addition, since no diaphragm is provided inside the column, there is no need to check the diaphragm from the outside of the column. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2003-268877 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the beam-column joint structure of Patent Document 1, when an external force due to an earthquake or the like is applied to the joint portion, which is the connection portion between the column and the beam, large stress and strain are concentrated at the joint end of the beam. Therefore, damage to the joint end of the beam or deformation of the joint due to the beam being pushed in may occur. In addition, in a non-diaphragm type frame such as the beam-column joint structure of Patent Document 1, there is a problem that the deformation of the joint is larger than that of a through diaphragm type frame or an internal diaphragm type frame. In other words, in a non-diaphragm type frame such as the beam-column joint structure of Patent Document 1, there is a problem that its rigidity is smaller than that of a through diaphragm type frame or an internal diaphragm type frame.

[0006] Therefore, an object of the present invention is to provide a column-beam joint structure in a non-diaphragm type frame that has the same rigidity as a through diaphragm type frame or an internal diaphragm type frame. [Means for solving the problem]

[0007] The problem to be solved by the present invention has been described above. Next, the means for solving this problem will be described.

[0008] That is, the beam-column joint structure of the present invention is a beam-column joint structure comprising a column portion made of a square steel pipe, a beam portion made of an H-shaped steel having a pair of flanges and a web connecting the flanges, a non-diaphragm type joint portion made of a square steel pipe and serving as a connection portion between the column portion and the beam portion, and a flat horizontal haunch provided between an end face on one end side of the flange and a side surface of the joint portion, and the joint portion is configured such that the relationship between the plate thickness tp of the joint portion and the outer diameter Bc of the column portion satisfies tp≧(Bc / 10)+5. the relationship between the excess length e of the excess portion formed between the upper end and / or lower end of the connection portion and the upper end and / or lower end of the beam portion and the outer diameter Bc of the column portion is e ≧ Bc / 4, the horizontal haunch is formed so that the relationship between the widthwise length W of the horizontal haunch and the widthwise length W1 of the flat portion of the connection portion is W ≧ W1, and the relationship between the lengthwise length L of the horizontal haunch and the outer diameter Bc of the column portion and the widthwise length W2 of the flange is L ≧ Bc-W2. Effect of the Invention

[0009] According to the beam-column joint structure of the present invention, a horizontal haunch formed under specified conditions is provided on one end side of the flange of the beam, which is the beam end of the beam-column joint, and a non-diaphragm type joint formed under specified conditions is further combined, so that the rigidity of the frame can be increased and a non-diaphragm type frame having the same rigidity as a through diaphragm type frame or an inner diaphragm type frame can be constructed. Therefore, in the structural design of a building that employs a non-diaphragm type, the beam end of the beam can be modeled as a rigid joint. [Brief description of the drawings]

[0010] [Figure 1] 1 is a partially cutaway perspective view of a main portion of a column-beam joint structure according to the present invention; [Diagram 2] 1 is a longitudinal sectional front view of a main portion of a column-beam joint structure according to the present invention. [Diagram 3] 1 is a cross-sectional plan view of a main portion of a column-beam joint structure according to the present invention. [Figure 4] 2 is a partially enlarged cross-sectional plan view of a main portion of the column-beam joint structure according to the present invention. FIG. [Diagram 5] FIG. 1 is a schematic diagram showing an analytical model of a beam-column joint structure used in the FEM analysis. [Figure 6] This is a schematic diagram of the General Yield method used in the FEM analysis. [Figure 7] FIG. 13 is a diagram showing a list of the results of the FEM analysis. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. First, a column-beam joint structure 10 according to the present invention will be described. Note that the present invention is not limited to the column-beam joint structure 10 described below.

[0012] As shown in Figure 1, the column-beam joint structure 10 is composed of upper and lower column shafts 11A, 11B (an example of a "column portion") extending in the vertical direction, a joint core 12 (an example of a "joint portion") arranged between the upper and lower column shafts 11A, 11B, beams 13 (an example of a "beam portion") extending horizontally from each of the outer surfaces 12c facing in all four directions of the joint core 12, and a built H-shaped steel 30 arranged between the outer surfaces 12c of the joint core 12 and an end face on one end side of the beam 13.

[0013] As shown in Figs. 1 to 3, the column shafts 11A and 11B are long rectangular steel pipes that are heated by a heating means such as a heating furnace and hot-formed by a forming means such as a forming roll device. The outer diameter Bc (shaft width) of the column shafts 11A and 11B is 200 mm to 550 mm. The plate thickness tc of the column shafts 11A and 11B is 9 mm to 25 mm. The outer curvature radius of the corner portion 11a of the column shafts 11A and 11B is set to be 2.0 to 3.0 times the plate thickness tc of the column shafts 11A and 11B. The column shafts 11A and 11B have grooves of a predetermined angle formed by cutting the outer parts of their ends by a processing means such as a cutting device.

[0014] The joint core 12 is a short rectangular steel pipe heated by a heating means such as a heating furnace and hot formed by a forming means such as a forming roll device. As shown in Figs. 1 to 3, the joint core 12 is a connection between the column shafts 11A, 11B and the beam 13, and is configured in a non-diaphragm form. The height H1 of the joint core 12 in the longitudinal direction (vertical direction) is set to be longer than the height H2 of the beam 13 (height between the upper and lower flanges 13a). The outer diameter Bp of the joint core 12 is 220 mm to 575 mm. The plate thickness (panel thickness) tp of the joint core 12 is 19 mm to 50 mm. Here, the plate thickness (panel thickness) tp of the joint core 12 is determined in relation to the outer diameter (shaft width) Bc of the joined column shafts 11A, 11B, and is formed so that the relationship between the plate thickness (panel thickness) tp of the joint core 12 and the outer diameter (shaft width) Bc of the upper and lower column shafts 11A, 11B satisfies tp≧(Bc / 10)+5. For example, when the outer diameter Bc of the column shafts 11A, 11B is 400 mm, the plate thickness tp of the joint core 12 is set to 45 mm or more. The outer radius of curvature of the corner portion 12a of the joint core 12 is set to 1.5 to 2.5 times the plate thickness tp of the joint core 12. Here, the outer radius of curvature of the corner portion 12a of the joint core 12 refers to the radius of curvature at the outer intersection of the corner portion 12a and a line that forms a 45 degree angle with the side perpendicular to the adjacent inner and outer surfaces of the joint core 12.

[0015] As shown in Fig. 1 and Fig. 2, in the column-beam joint structure 10, the column shafts 11A, 11B and the joint core 12 are arranged in a straight line. Specifically, the lower end of the joint core 12 is arranged at the upper end of the lower column shaft 11B, and the upper end of the joint core 12 is arranged at the lower end of the upper column shaft 11A. That is, the joint core 12 is arranged so as to be sandwiched between the column shafts 11A, 11B from above and below. The column shafts 11A, 11B and the joint core 12 are joined from the outside by welding 17. In the column-beam joint structure 10, the outer diameter Bp of the joint core 12 is set to be longer than the outer diameter Bc of the column shafts 11A, 11B so that the end faces of the column shafts 11A, 11B can be placed on the end faces of the joint core 12.

[0016] 1 to 3, the beam 13 is formed of an H-shaped steel. The beam 13 is composed of two opposing flat flanges 13a and a web 13b formed between the opposing flanges 13a. The beam 13 is disposed so that the flanges 13a face each other in the vertical direction, and one end side of the flanges 13a and the web 13b are welded to the built H-shaped steel 30.

[0017] The built H-shaped steel 30 is a member having a substantially H-shape. One end of the built H-shaped steel 30 is welded to one end of the beam 13, and the other end of the built H-shaped steel 30 is welded to the outer surface 12c of the joint core 12. As a result, the built H-shaped steel 30 is provided between the outer surface 12c of the joint core 12 and one end of the beam 13, and joins the joint core 12 and the beam 13. The built H-shaped steel 30 is composed of two opposing flat horizontal haunches 31 and a partition plate 32 formed between the opposing horizontal haunches 31.

[0018] The horizontal haunch 31 is formed of a substantially rectangular flat plate member having the same thickness as the flange 13a of the beam 13. One end surface of the horizontal haunch 31 is welded to one end surface of the flange 13a. The other end surface of the horizontal haunch 31 is welded to the outer surface 12c of the joint core 12. Specifically, the horizontal haunch 31 and the flange 13a are joined by welding 34 with a first backing metal 33 abutting one end side of the horizontal haunch 31 and one end side of the flange 13a. Also, the horizontal haunch 31 and the outer surface 12c of the joint core 12 are joined by welding 36 with a second backing metal 35 abutting the other end side of the horizontal haunch 31 and the outer surface 12c of the joint core 12. By providing the horizontal haunch 31 between the outer surface 12c of the joint core 12 and one end of the beam 13, the stress generated in the joint core 12 is reduced, and the out-of-plane deformation of the steel pipe wall of the joint core 12 is reduced.

[0019] 4, the flange width W of the horizontal haunch 31 (the length of the portion welded to one end face of the flange 13a and the outer side face 12c of the joint core 12) is equal to or greater than the widthwise length W1 (the length between the two R stops R0 at both ends of each side face of the joint core 12) (W≧W1) of the flat plate portion 12s of the joint core 12. Specifically, the flange width W of the horizontal haunch 31 is set to a length that allows both ends of the end face of the horizontal haunch 31 to be located at the intermediate position R2 (the intermediate position between the apex R1 of the corner portion 12a of the joint core 12 and the R stop R0 of the corner portion 12a including the apex R1) when the other end face of the horizontal haunch 31 is welded to the side face (flat plate portion 12s) of the joint core 12. 4, the apex R1 of the corner portion 12a of the joint core 12 refers to the position where the outer diameter side surface of the corner portion 12a of the joint core 12 intersects with the diagonal line T of the joint core 12. Also, the R end point R0 of the corner portion 12a refers to the position on the outer diameter side surface of the corner portion 12a where the curved portion of the corner portion 12a ends (the position where the flat portion 12s on the side surface of the joint core 12 starts).

[0020] The flange length L of the horizontal haunch 31 (length in a direction horizontally perpendicular to the flange width W) is set based on the relationship between the outer diameter Bc of the column shafts 11A and 11B and the width W2 of the flange 13a (length of the portion welded to the horizontal haunch 31). Specifically, the horizontal haunch 31 is formed so that the flange length L satisfies L≧Bc-W2. For example, when the outer diameter Bc of the column shafts 11A and 11B is 400 mm and the width W2 of the flange 13a is 200 mm, the flange length L of the horizontal haunch 31 is set to 200 mm or more. In the non-diaphragm type joint core 12, the flange length L of the horizontal haunch 31 provided at the top and bottom of the joint core 12 greatly affects the rigidity and strength of the non-diaphragm type frame.

[0021] 1 to 3, the partition plate 32 is made of a flat member having the same thickness as the web 13b of the beam 13. One end surface of the partition plate 32 is welded to one end surface of the web 13b. The other end surface of the partition plate 32 is welded to the outer surface 12c of the joint core 12.

[0022] The excess length e of the excess portion 15 of the joint core 12 (the portion formed between the upper end and / or lower end of the joint core 12 and the upper end (upper surface) and / or lower end (lower surface) of the flange 13a of the beam 13) is set based on the outer diameter Bc of the column shafts 11A, 11B. Specifically, the excess portion 15 of the joint core 12 is formed so that the excess length e satisfies e≧Bc / 4. For example, when the outer diameter Bc of the column shafts 11A, 11B is 400 mm, the excess length e of the excess portion 15 of the joint core 12 is set to 100 mm or more.

[0023] As described above, in the beam-column joint structure 10, the joint core 12 is configured in a non-diaphragm form. The joint core 12 is formed in a thickened column so that the relationship between the plate thickness tp of the joint core 12 and the outer diameter Bc of the column shafts 11A and 11B is tp≧(Bc / 10)+5. The excess length portion 15 of the joint core 12 is formed so that the relationship between the excess length e of the excess length portion 15 of the joint core 12 and the outer diameter Bc of the column shafts 11A and 11B is e≧Bc / 4. The beam 13 is formed of an H-shaped steel beam including the built H-shaped steel 30 of the horizontal haunch 31 at the beam end. The horizontal haunch 31 is formed so that the relationship between the width direction length W of the horizontal haunch 31 and the width direction length W1 of the flat plate portion 12s of the joint core 12 is W≧W1. Furthermore, the horizontal haunch 31 is formed so that the relationship between the length L in the longitudinal direction of the horizontal haunch 31, the outer diameter Bc of the upper and lower column shafts 11A, 11B, and the width W2 of the flange 13a is L≧Bc-W2. By configuring the column-beam connection structure 10 under the above conditions, the column-beam connection structure 10 can configure a column-beam connection structure having the same rigidity as a through diaphragm type frame or an internal diaphragm type frame in a non-diaphragm type frame.

[0024] Next, the effects of the present invention were confirmed by FEM analysis, and will be described in the following examples. EXAMPLES

[0025] In the following Examples 1-1 to 1-5A, the column shafts 11A and 11B in the column-beam joint structure 10 are made of square steel pipes of □-400×400×19 (R=75) and SHC490B that are hot roll-formed, and the beam 13 is made of square steel pipes of H-600×300×12×22 and F-value 235N / mm 2 or 325N / mm 2 FEM analysis was performed using a non-diaphragm type cross-shaped groove (test specimen) made of SN400B or SN490B H-shaped steel.

[0026] The joint core 12 of the cross-shaped frame groove in Examples 1-1 and 1-1A was made of a hot-formed square steel pipe of SHC490C, measuring □-410×410×40 (R=80). In Example 1-1, the plate thickness (panel thickness) tp of the joint core 12 was 40 mm, the extra length e of the extra length portion 15 of the joint core 12 was 100 mm, the width (beam width) W2 of the flange 13a was 300 mm, and the F value of the beam 13 was 235 N / mm 2 In Example 1-1A, the plate thickness tp of the joint core 12 was 40 mm, the extra length e of the extra length portion 15 of the joint core 12 was 100 mm, the width W2 of the flange 13a was 300 mm, and the F value of the beam 13 was 325 N / mm 2 Furthermore, the beams 13 of the cross-shaped frame groove in Examples 1-1 and 1-1A were made of H-shaped steel of SN490B.

[0027] The joint core 12 of the cross-shaped frame groove in Example 1-2 was made of a hot-formed square steel pipe of SHC490C, measuring □-410×410×40 (R=80). In Example 1-2, the plate thickness tp of the joint core 12 was 40 mm, the extra length e of the extra length portion 15 of the joint core 12 was 50 mm, the width W2 of the flange 13a was 300 mm, and the F value of the beam 13 was 235 N / mm 2 Furthermore, the beam 13 of the cross-shaped frame groove in Example 1-2 was made of H-shaped steel of SN400B.

[0028] The joint core 12 of the cross-shaped frame groove in Example 1-3 was made of a hot-formed square steel pipe of SHC490C, measuring □-410×410×36 (R=80). In Example 1-3, the plate thickness tp of the joint core 12 was 36 mm, the extra length e of the extra length portion 15 of the joint core 12 was 100 mm, the width W2 of the flange 13a was 300 mm, and the F value of the beam 13 was 235 N / mm 2 Furthermore, the beam 13 of the cross-shaped frame groove in Example 1-3 was made of H-shaped steel of SN400B.

[0029] The joint core 12 of the cross-shaped frame groove in Examples 1-4, 1-5, and 1-5A was made of a hot-formed square steel pipe of SHC490C, measuring □-410×410×45 (R=80). In Example 1-4, the plate thickness tp of the joint core 12 was 45 mm, the extra length e of the extra length portion 15 of the joint core 12 was 50 mm, the width W2 of the flange 13a was 300 mm, and the F value of the beam 13 was 235 N / mm 2 In Example 1-5, the plate thickness tp of the joint core 12 was 45 mm, the extra length e of the extra length portion 15 of the joint core 12 was 30 mm, the width W2 of the flange 13a was 300 mm, and the F value of the beam 13 was 235 N / mm 2 Furthermore, in Example 1-5A, the plate thickness tp of the joint core 12 was 45 mm, the extra length e of the extra length portion 15 of the joint core 12 was 30 mm, the width W2 of the flange 13a was 300 mm, and the F value of the beam 13 was 325 N / mm 2 Furthermore, the beams 13 of the cross-shaped frame groove in Examples 1-4, 1-5, and 1-5A were made of H-shaped steel of SN490B.

[0030] In Comparative Example 1 for Examples 1-1 to 1-5A, the column shafts 11A and 11B in the column-beam joint structure 10 were constructed from hot-roll-formed square steel pipes of □-400×400×19 (R=75) and SHC490B, and the beam 13 was a through-diaphragm type cruciform frame groove (test specimen) constructed from H-shaped steel of H-600×300×12×22 and SN400B, and FEM analysis was performed.

[0031] The joint core 12 of the cross-shaped frame groove in Comparative Example 1 was made of a hot-formed square steel pipe of SHC490B, measuring □-400×400×19 (R=75). Furthermore, the diaphragm was made of a plate material of SN490C with a plate thickness of 28 mm. EXAMPLES

[0032] In the following Examples 2-1 to 2-4, the column shafts 11A and 11B in the column-beam joint structure 10 are made of square steel pipes of □-400×400×19 (R=75) and SHC490B that are hot roll-formed, and the beam 13 is made of square steel pipes of H-600×200×12×22 and F-value 235N / mm 2 or 325N / mm 2 FEM analysis was performed using a non-diaphragm type cross-shaped frame groove (test specimen) made of SN400B H-shaped steel.

[0033] The joint core 12 of the cross-shaped frame groove in Examples 2-1 and 2-2 was made of a hot-formed square steel pipe of SHC490C, measuring □-410×410×40 (R=80). In Example 2-1, the plate thickness tp of the joint core 12 was 40 mm, the extra length e of the extra length portion 15 of the joint core 12 was 100 mm, the width W2 of the flange 13a was 200 mm, and the F value of the beam 13 was 235 N / mm 2 In Example 2-2, the plate thickness tp of the joint core 12 was 40 mm, the extra length e of the extra length portion 15 of the joint core 12 was 150 mm, the width W2 of the flange 13a was 200 mm, and the F value of the beam 13 was 235 N / mm 2 It was decided.

[0034] The joint core 12 of the cross-shaped frame groove in Examples 2-3 and 2-3A was made of a hot-formed square steel pipe of SHC490C, measuring □-410×410×45 (R=80). In Example 2-3, the plate thickness tp of the joint core 12 was 45 mm, the extra length e of the extra length portion 15 of the joint core 12 was 100 mm, the width W2 of the flange 13a was 200 mm, and the F value of the beam 13 was 235 N / mm 2 Furthermore, in Example 2-3A, the plate thickness tp of the joint core 12 was 45 mm, the extra length e of the extra length portion 15 of the joint core 12 was 100 mm, the width W2 of the flange 13a was 200 mm, and the F value of the beam 13 was 325 N / mm2 It was decided.

[0035] The joint core 12 of the cross-shaped frame groove in Example 2-4 was made of a hot-formed square steel pipe of SHC490C, measuring □-410×410×45 (R=80). In Example 2-4, the plate thickness tp of the joint core 12 was 45 mm, the extra length e of the extra length portion 15 of the joint core 12 was 50 mm, the width W2 of the flange 13a was 200 mm, and the F value of the beam 13 was 235 N / mm 2 Comparative Example 2

[0036] In Comparative Example 2 for Examples 2-1 to 2-4, FEM analysis was performed using a through-diaphragm type cross-shaped frame groove (test specimen) in which the column shafts 11A and 11B in the column-beam joint structure 10 were constructed from hot-roll-formed square steel pipes of □-400×400×19 (R=75) and SHC490B, and the beam 13 was constructed from H-shaped steel of H-600×200×12×22 and SN400B.

[0037] The joint core 12 of the cross-shaped frame groove in Comparative Example 2 was made of a hot-formed square steel pipe of SHC490B, measuring □-400×400×19 (R=75). Furthermore, the diaphragm was made of a plate material of SN490C with a plate thickness of 28 mm.

[0038] As shown in Figure 5, in this example, the above test specimen was modeled as a 1 / 2 symmetrical model. The connection core 12, column shafts 11A and 11B, and beam 13 were modeled with 8-node solid elements (complete integral elements) from the ends to the centers of the members, and 2-node beam elements (linear material elements) from the center to the tip of the members. The connections between the beam elements and solid elements were made such that the beam element end junctions were set as independent nodes, and the solid element face nodes were set as dependent nodes, so that the connection positions maintained a flat surface. As constraint conditions, the solid element portions were restrained from displacing in the out-of-plane direction at the symmetrical plane (U z =0), and the beam element is constrained against out-of-plane displacement, out-of-plane rotation, and torsional rotation (U z =0, θ x =0, θ y =0), and the ends of the beam elements other than the load points are supported by rollers that allow freedom in the material axial direction (Beam 13: U y=0, upper and lower pillar shafts 11A, 11B:U x The analysis took into account the material geometric nonlinearity and was an incremental analysis with displacement control at the tip of the upper column shaft 11A (up to 1 / 10 rad in inter-story drift angle).

[0039] The yield strength Qy obtained by FEM load deformation and the total plastic strength Qp obtained by FEM load deformation were calculated by the General Yield method shown in Fig. 6. In Fig. 7, sQy is the short-term horizontal strength (kN) of the frame determined from the short-term strength of each part, sQp is the total plastic strength (kN) of the frame determined from the short-term strength of each part, sKj is the external bending rotation rigidity (kN.m / rad) of the side of the joint core 12, K0 is the initial rigidity (kN / mm) obtained by FEM load deformation, Ka is the secant rigidity (kN / mm) at the short-term yield strength sQy obtained by FEM load deformation, and TDK0 is the initial rigidity (kN / mm) of the through diaphragm type frame with the same beam width.

[0040] In this FEM analysis, the test subject was a non-diaphragm type cruciform specimen subjected to horizontal load, in which hot-formed square steel pipes (SHC material) were used for the column shafts 11A, 11B and the connection core 12. FEM analysis was performed, compared, and examined for Examples 1-1 to 1-5A, Examples 2-1 to 2-4, and Comparative Examples 1 and 2, with the plate thickness tp of the connection core 12, the excess length e of the excess portion 15 of the connection core 12, the width W2 of the flange 13a, and the F-value of the beam 13 (beam material standard strength Fb) being the analytical variables.

[0041] The calculated horizontal strength values ​​sQy and sQp of the non-diaphragm type frame shown in Figure 7 are on the safe side compared to the results of the FEM analysis, and there are no problems with their use in structural design. Since the stress at the edge of the flange 13a, which is the end of the beam 13, is predominant, it is preferable to hold the welded part with a backing metal, end tab, etc., especially when the edge of the flange 13a is applied to the R part of the joint core 12.

[0042] In the case of a non-diaphragm type frame, the horizontal rigidity of the frame can be increased or decreased by increasing or decreasing the plate thickness tp of the connection core 12 or the extra length e of the extra length 15 of the connection core 12, but the plate thickness tp of the connection core 12 has a greater effect on the rigidity of the frame than the extra length e of the extra length 15 of the connection core 12. Depending on the plate thickness tc of the column shafts 11A, 11B and the type of steel, the extra length e of the extra length 15 of the connection core 12 may have a greater effect on the rigidity of the frame than the plate thickness tp of the connection core 12.

[0043] In the case of a non-diaphragm type frame, even if the cross-sectional dimensions of the joint core 12 (plate thickness tp of the joint core 12, excess length e of the excess portion 15 of the joint core 12) are the same, the out-of-plane bending rotational rigidity (secant rigidity) Kj of the joint core 12 changes significantly depending on the width W2 of the flange 13a, and has a large impact on the horizontal rigidity of the frame.

[0044] The secant stiffness Ka of a non-diaphragm type frame at the time of short-term horizontal strength sQy is not significantly affected by the material strength of the beam material in beam 13 (beam material reference strength Fb).

[0045] The out-of-plane bending rotation stiffness sKj of the joint core 12 shown in Figure 7 is evaluated with an accuracy of within a 10% error range, and in some cases it is considered acceptable for structural design, but there are also cases where the error exceeds 20%. The evaluation tendency is that the beam steel material's standard strength Fb of the beam 13 is 235N / mm 2 In this case, rotational rigidity tends to be evaluated highly, and Fb=325N / mm 2 In this case, rotational stiffness tends to be estimated as small.

[0046] In Examples 1-1 to 1-5A and Examples 2-1 to 2-4, the ratio Ka / TDK0 of the secant stiffness Ka of the non-diaphragm type frame to the initial stiffness TDK0 of the through diaphragm type frame exceeds "0.95," and when modeling the beam end of beam 13 as a rigid joint rather than a semi-rigid joint at the node in modeling the frame in the structural design of the building is performed, the test specimen dimensions are extracted for the seven cases shown in FIG. 7, which are Examples 1-1, 1-1A, 1-4, 1-5, 1-5A, 2-3, and 2-3A (the examples hatched in FIG. 7).

[0047] In these seven examples (Examples 1-1, 1-1A, 1-4, 1-5, 1-5A, 2-3, and 2-3A), the common conditions under which the beam end of the beam 13 can be regarded as a rigid connection are the following two conditions. (1)tp≧(Bc / 10)+5 tp: thickness of joint core 12 (panel thickness) Bc: Outer diameter of column shafts 11A and 11B (shaft width) (2) e ≧ Bc / 4 e: Extra length of the extra length portion 15 of the joint core 12 Bc: Outer diameter of column shafts 11A and 11B (shaft width)

[0048] Furthermore, by providing the beam end of the beam 13 with a built H-shaped steel 30 having a horizontal haunch 31, the beam end of the beam 13 can be modeled as a rigid joint for structural calculation. Therefore, the column shafts 11A, 11B and the beam 13 are combined in consideration of the placement of the built H-shaped steel 30 having the horizontal haunch 31 that satisfies the following two conditions. (1) W ≥ W1 W: Flange width of the horizontal haunch 31 (the length of the portion welded to one end face of the flange 13a and the outer surface 12c of the joint core 12) W1: The width of the flat portion 12s of the joint core 12 (the length between the two R stops R0 at both ends of each side of the joint core 12) (2) L ≥ Bc-W2 L: Flange length of horizontal haunch 31 (length in the direction perpendicular to flange width W) Bc: Outer diameter of column shafts 11A and 11B (shaft width) W2: Width of flange 13a (length of the portion welded to horizontal haunch 31)

[0049] As described above, the horizontal haunch 31 formed under the specified conditions (W≧W1, L≧Bc-W2) is provided on one end side of the flange 13a of the beam 13, which is the beam end of the column-beam joint, and further combined with the non-diaphragm type joint core 12 formed under the specified conditions (tp≧(Bc / 10)+5, e≧Bc / 4), the rigidity of the frame can be increased, and a non-diaphragm type frame with the same rigidity as a through diaphragm type frame or an internal diaphragm type frame can be constructed. Therefore, in the structural design of a building that employs the non-diaphragm type, the beam end of the beam 13 can be modeled as a rigid joint. [Explanation of symbols]

[0050] 10 Column beam joint structure 11A Pillar shaft (pillar section) 11B Pillar shaft (pillar section) 12 Joint core (joint section) 12s flat plate part 13 Beam (beam part) 13a Flange 13b Web 31 Horizontal corbel

Claims

[Claim 1] A column portion made of a square steel pipe; A beam portion formed of an H-shaped steel having a pair of flanges and a web connecting the flanges; A non-diaphragm type joint portion that is made of a square steel pipe and serves as a connection portion between the column portion and the beam portion; A flat horizontal haunch provided between an end surface of one end of the flange and a side surface of the joint portion; A column-beam joint structure comprising: The joint portion is The relationship between the plate thickness tp of the joint portion and the outer diameter Bc of the column portion is tp ≧ (Bc / 10) + 5, The relationship between the margin e of the margin portion formed between the upper end and / or lower end of the joint portion and the upper end and / or lower end of the beam portion and the outer diameter Bc of the column portion is e ≧ Bc / 4, The horizontal haunch is The relationship between the width direction length W of the horizontal haunch and the width direction length W1 of the flat portion of the joint portion is formed so that W≧W1; The horizontal haunch has a length L in the longitudinal direction, an outer diameter Bc of the column portion, and a width direction W2 of the flange such that the relationship is L≧Bc-W2. A column-beam joint structure characterized by:

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