JP5754238B2 - Beam-column joint structure - Google Patents

Description

  The present invention relates to a column beam joint structure for welding a through-diaphragm of a steel column such as a square steel pipe column or a weld box column and a steel beam such as an H-shaped steel or an I-shaped steel having parallel flanges in the vertical direction.

  Many joint structures have been proposed for welding steel beams made of H-shaped steel to steel columns made of closed section columns such as steel pipe columns and welded box columns (for example, Patent Documents 1 and 2). In many cases, the welded joint structure shown in FIGS.

  FIG. 5 shows a case where a steel beam (beam bracket) 2 grooved on the beam flange 2a is welded to the steel column 1 in the case of factory welding (FIGS. 5 (a) and 5 (c)). The end of the beam bracket 2 on the steel column 1 side is processed so that the beam flange 2a and the through diaphragm 3 that reinforces the steel column 1 are completely melted and joined by welding.

  Therefore, the groove 4 of the beam flange 2a is processed so that a root gap is obtained in the groove portion of the diaphragm 3 through the beam flange 2a in a state where the beam web 2b is in contact with the steel column 1 (FIG. 5). (B)).

  The steel beam (beam bracket) 2 and the steel column 1 are welded in a state where the backing metal 50 is tack welded to the beam flange 2a by fillet welding, but the welding is performed at the welded portion of the steel column 1 and the beam web 2b. As possible, scallops 5 are formed above and below the beam web 2b. In addition, the end tab 51 is provided in the both ends of the beam width direction of the backing metal 50, and the welding defect in the beam width end part is prevented by welding to this end tab.

  FIG. 6 shows a case of on-site welding, and a gusset plate 8 that holds the steel beam 2 in advance is attached to the steel column 1 by welding so that the steel beam 2 can be suspended between the steel columns 1 to form a column beam structure. (FIG. 6A).

  The beam web 2b sandwiched between the gusset plates 8 is temporarily fixed with bolts 9 and then butt welding is performed. After the welding is finished, the bolts 9 are finally tightened to join the steel column 1 and the steel beam 2 together. Also in the case of field welding, the end on the steel column 1 side of the steel beam (beam bracket) 2 is processed so that the beam flange 2a and the through diaphragm 3 that reinforces the steel column 1 are joined by complete penetration welding. However, the groove of the beam flange 2a is machined so that a downward welding operation is possible (FIG. 6B).

JP-A-11-210158 JP 2010-90595 A

  However, the conventional welded joint shown in FIGS. 5 and 6 suffered much damage when a strong bending moment (sometimes referred to as bending) was applied in the 1995 Hyogoken-Nanbu Earthquake. The damage is due to the occurrence and fracture of various cracks in the welded end of the beam, in the vicinity of the scallop, near the end tab, etc., in addition to the deterioration of the toughness of the material, defects in the weld, scalloped shape, end tab and through diaphragm 3 and beam flange This was due to the welded structure itself, such as a discontinuity in shape due to the difference in plate thickness 2a.

  In particular, when the column has a hollow cross section such as a square steel pipe, the beam web 2b often does not effectively contribute to the beam end strength, and stress concentrates on the beam flange 2a, so that a crack generated from the scallop bottom or the end tab is generated. A number of examples of progress and breakage of the beam flange 2a were observed.

  The present invention has been made in view of the above-mentioned damage state in the beam-column joint, and prevents the occurrence of weld defects in the welded joint between the column side and through diaphragm and beam flange, and the beam end is reinforced. An object of the present invention is to provide a beam-column joint structure capable of preventing the beam flange from being broken even when bending is caused by an earthquake or the like.

The object of the present invention can be achieved by the following means.
(1) A beam-to-column connection structure in which a beam made of steel having upper and lower flanges is welded to a steel column, wherein the steel column and the beam are joined by a steel column beam flange welded joint and a steel column beam A web weld joint,
The steel column beam flange welded joint is a joint obtained by completely melting and welding the groove part of the beam flange and the plate-like member joined to the outside thereof and a through diaphragm of the steel column,
The steel column beam web welded joint is a welded portion of the steel column skin plate and the beam web butting portion welded,
The beam web is provided with scallops for welding the steel column beam flange welded joint and the steel column beam web welded joint,
The plate-like member has a plate thickness obtained by subtracting the plate thickness of the flange of the beam from the through diaphragm, has a plate width substantially the same as the flange width of the beam, and is appropriately disposed on the opposite side from the steel column beam flange weld joint. A beam-to-column connection structure characterized by having a length and being bolted to the beam flange by a high strength bolt.

  According to the present invention, it is possible to prevent the beam flange from being broken even if a strong bending moment due to a large earthquake acts on the column beam connection structure, which is extremely useful in the industry.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure explaining the case of factory welding with the beam-column joining structure which concerns on one Example of this invention, (a) is a side view, (b) is the A section detailed drawing of (a), (c) is (a). B-B arrow view, (d) is a cc arrow view of (a). The figure which shows the other groove shape in the column beam junction structure shown in FIG. It is a figure explaining the case of field welding in the column beam connection structure concerning other examples of the present invention, (a) is a side view, (b) is the A section detailed drawing of (a), (c) is (a). BB arrow view of (a), cc arrow view of (a). The design example of the column beam junction structure which concerns on this invention. It is a figure which shows the case of factory welding by the welding joint part structure of the conventional pillar and beam, (a) is a side view, (b) is the A section detail drawing of (a), (c) is B- of (a). B arrow view. It is a figure which shows the case of the field welding of the conventional welded-joint structure of a pillar and a beam, (a) is a side view, (b) is the A section detail drawing of (a), (c) is B- of (a). B arrow view.

  The column beam connection structure according to the present invention is a connection structure in which a beam flange of a steel beam reinforced with a plate-like member is welded to a side surface or through diaphragm of a steel column by complete penetration welding.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a case where a beam-column joint structure according to an embodiment of the present invention is manufactured by factory welding, FIG. 1 (a) is a side view of a beam-column joint, and FIG. 1 (b) is FIG. FIG. 1C is a view for explaining a welding joint part in a detailed view of A part of FIG. 1B, and FIG. 1 (d) is a view taken along the line cc in FIG. 1 (a) and illustrates a state in which the beam web is attached to the steel column.

  In these drawings, 1 is a steel column, 1a is a skin plate, 2 is a steel beam, 2a is a beam flange, 2b is a beam web, 3 is a through diaphragm, 4 is a groove, 5 is a scallop, and 6 is a fillet weld. , 7 is a butt weld, 9 is a high strength bolt, 10 is a plate-like member, 10a is a groove of the plate-like member, and 50 is a backing metal.

  The joint between the steel column 1 and the steel beam 2 shown in the figure includes (a) a steel column beam flange welded joint where the through diaphragm 3 of the steel column 1 and the beam flange 2a are welded together, and (b) the steel column 1 and the beam web 2b. Steel beam-to-beam web welded joints.

  The steel column beam flange welded joint is a joint in which the plate-like member 10 joined to the outer side of the beam flange 2a (opposite side of the beam web 2b) and the beam flange 2a are welded to the diaphragm 3, and through the diaphragm 3 side. The beam-shaped groove 4 in which the beam flange 2a and the plate-like member 10 side are grooved obliquely in a straight line is welded. The beam flange 2 a and the plate-like member 10 are connected by a high-strength bolt 9.

  The plate thickness of the plate-like member 10 joined to the outside of the beam flange 2a (the opposite side of the beam web 2b) is obtained by subtracting the plate thickness of the beam flange 2a from the plate thickness of the through diaphragm 3, and the plate width is the beam width. It is substantially the same as the beam width of the flange 2a.

  Since the groove 4 has a root gap to which the backing metal 50 is applied, and the plate thickness of the through diaphragm 3 and the total plate thickness of the plate member 10 joined to the beam flange 2a are substantially equal over the weld length, A completely butt weld 7 with no weld defects is obtained. When the plate member 10 is thin, the groove 10a of the plate member is omitted because a weld defect is unlikely to occur without performing groove processing that is aligned with the beam flange 2a (FIG. 2).

  The length of the plate-like member 10 in the beam length direction may be appropriately determined according to the desired beam rigidity, and is not particularly defined in the present invention, but is several times the width of the backing metal 50 in the beam length direction. Is desirable.

  The steel beam-to-beam flange welded joint of the beam-to-column welded joint according to the present invention is a complete penetration welded part, there is no discontinuous part of the plate thickness in the vicinity of the welded part of the through diaphragm 3 and the beam flange 2a, and the beam flange 2a. Since the plate-like member 10 is bolted and no welding defect occurs, the beam end strength is excellent. That is, when the bending end acts on the beam end portion, the positive plasticizing portion becomes the tip in the material length direction of the plate-like member, and when the portion is welded to the beam flange 2a by fillet welding, the quality of the welding (undercut or the like) Depending on the welding defects, there is a possibility of brittle fracture without sufficient plasticization, but in the case of bolt connection there is no fear.

  The steel beam-to-beam welded joint is a fillet welded portion 6 in which the beam web 2b is fillet welded to the skin plate 1a of the steel column 1, and a groove having an appropriate shape is formed according to the plate thickness of the beam web 2b. Apply. When the plate thickness is thin, groove processing is not necessary. When the plate thickness is thick, a labyrinth with a straight skin plate 1a is used so as to achieve complete penetration welding. The groove processing may be performed on either side or one side of the beam web 2b.

  The beam web 2b is provided with a scallop 5 for avoiding interference between the fillet weld turn weld and the backing metal 50 of the steel column beam flange weld joint. The bending is transmitted to the steel column 1 via the upper and lower beam flanges 2a, and the shearing force is transmitted to the steel column 1 via the beam web 2b. Fix to 1a.

  In the case of the factory welding shown in the drawing, the construction is performed by fastening the plate member 10 to the beam flange 2a with high-strength bolts 9, and then fixing the steel column 1 and the steel beam 2 together with the butt weld portion 7 including the plate member 10. Thus, the plate-like member 10 is connected to the beam flange 2 a of the steel beam 2 and the through diaphragm 3 of the steel column 1.

  Further, in the case of factory welding, since welding can be performed in an optimal welding posture such as downward welding or sideways welding, the plate-like member 10 is positioned below the lower beam flange 2a, and the upper beam flange 2a A vertically symmetrical structure can be obtained.

  FIG. 3 shows a case where the beam-column joint structure according to another embodiment of the present invention is manufactured by field welding, FIG. 3 (a) is a side view of the beam-column joint, and FIG. 3 (b) is FIG. FIG. 3A is a detailed view of the A part of FIG. 3A, and FIG. 3C is a view illustrating the state of attachment of the plate-like member to the beam flange as viewed from the arrow B-B in FIG. FIG.3 (d) shows the figure explaining the attachment condition of the beam web to a steel column by the cc arrow line view of Fig.3 (a). In these figures, 8 indicates a gusset plate, and the same reference numerals as those in FIG.

  When manufacturing by field welding, the gusset plate 8 is attached to the steel column 1 by welding in advance, the steel beam 2 is suspended between the steel columns 1 and 1, and the beam web 2b is attached to the gusset plate 8 with high strength bolts 9. After temporarily fixing, the butt weld 7 including the plate-like member 10 is welded, and after the completion, the high-strength bolt 9 is finally tightened to join the steel column 1 and the steel beam 2.

  In general, since upward welding is not preferable for welding, in the field welding, the plate-like member 10 is positioned on the lower beam flange 2a and has the same positional relationship as the upper beam flange 2a. Thereby, the butt welding 7 can be performed downward also on the lower beam flange 2a side.

  In the above description, the steel column is limited to a closed cross-sectional column such as a steel tube column, but the present invention can also be applied to an open cross-sectional column such as an H-shaped steel column. Moreover, although the case where the steel beam is attached to the steel column from only one side is shown, it goes without saying that a plurality of steel beams are attached according to the outer column, the middle column, and the inner column.

  The beam-column joint according to the present invention is also effective when a beam flange is directly welded to a steel plate skin plate. In this case, the groove 4 is a groove with a straight skin plate and an obliquely processed beam flange side. Of the dimensions of the plate member, the plate thickness and the length in the beam length direction are appropriately determined according to the desired beam end strength.

  FIG. 4 shows a design example of the present invention. The steel column 1 is a 600 × 600 × 25 (mm) square steel pipe, the through diaphragm 3 is 36 mm thick, the beam 2 is H-800 × 300 × 14 × 28 (mm), and the bolt hole provided in the flange is formed at the end of the beam. The position is 300 mm from the butt weld and the diameter is φ18. The plate thickness of the plate member 10 is 4.5 mm.

  When it was checked whether the high-strength bolt 9 did not slide against the shearing force when the beam span was assumed to be 8000 mm, and the plate thickness of the plate-like member 10 was sufficient, there was no problem.

1 Steel Column 1a Skin Plate 2 Steel Beam 2a Beam Flange 2b Beam Web 3 Through Diaphragm 4 Groove 5 Scallop 6 Fillet Weld 7 Butt Weld 8 Gusset Plate 9 High Strength Bolt 10 Plate Member 10a Plate Member Groove 50 Back Pad 51 End tab

Claims (1)

A beam-to-column connection structure in which beams made of steel having upper and lower flanges are welded to a steel column, wherein the steel column and the beam are joined by a steel column beam flange welded joint and a steel column beam web welded joint. Part
The steel column beam flange welded joint is a joint obtained by completely melting and welding a groove portion formed by a flange of the beam, a plate-like member joined to the outside of the beam, and a through diaphragm of the steel column, and the steel column beam web. The welded joint is a joint that welds the skin plate of the steel column and the butted part of the web of the beam,
The beam web is provided with scallops for welding the steel column beam flange welded joint and the steel column beam web welded joint,
The plate-like member, a plate thickness obtained by subtracting the thickness of the flanges of the beam from the through diaphragm, at approximately the same plate width as the flange width before Kihari, suitably on the opposite side from the steel beam-to-column flange welded joints The beam-to-column connection structure is characterized in that the opposite side of the steel column is bolted to the beam flange with a high-strength bolt.

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