JP2001262698A - Connecting structure of square steel pipe column and steel beam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the strength and stress transfer performance of a column- beam connecting structure to connect a steel beam by an external diaphragm welded to a square steel pipe column. SOLUTION: A connecting plate 30 is fixed between the tips of a pair of upper and lower external diaphragms 22 connecting one steel beam 3 to a square steel pipe column 2, the tips of the external diaphragms 22 are connected to the flange 3b of the steel beam 3 by a cover plate 41 or the like, the connecting plate 30 and the web 3a of the steel beam 3 are connected by a joint plate 61 and a high strength bolt 70. The pair of upper and lower external diaphragms 22 is split into two split diaphragms 23 and 24, the upper and lower ends of the connecting plate 30 are fitted into and fixed to slit clearances g formed between the tips of the split diaphragms 23 and 24.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a beam-to-column connection structure in which a steel beam is connected to a square steel tubular column using an outer diaphragm.

[0002]

2. Description of the Related Art As a method for joining a rectangular steel tubular column and a flange portion of a steel beam in a steel structure, a diaphragm connecting the steel tubular column and the beam flange portion crosses the column and is fixed outside the column. There are known a through-diaphragm system protruding only by a length and an outer diaphragm system in which the diaphragm does not penetrate a pillar. The former through-diaphragm method has the advantage that the outside projection length of the diaphragm can be relatively short, so it is easy to transport from the factory to the site and the diaphragm does not get in the way during construction, but to penetrate the diaphragm through the pillar Once the column is cut and the diaphragm is inserted, the small end of the column must be welded again, and the welding and structural design are performed because the welded part is located at the most stressful place of the column Strict conditions are required, which is disadvantageous in terms of cost.

On the other hand, the latter outer diaphragm method has a problem in that it has a difficulty in transportability from the factory to the site because the outside projection length of the diaphragm is longer than the through-diaphragm, and there is a problem that the diaphragm hinders the construction. Fillet welding of the diaphragm to the column surface is sufficient without cutting the column, so that the strength of the column can be easily maintained, and it tends to be widely used for seismic resistance and cost advantages. In this outer diaphragm system, as shown in FIG. 17 (A), a diaphragm 2 around a square steel tubular column 1 is constituted by a single diaphragm, and a single diaphragm 1 is inserted through an insertion hole 2a formed in the center of the diaphragm 2. There are a diaphragm type and a divided diaphragm type in which the diaphragm 2 is formed of four small pieces and the small piece diaphragms are welded to each other near the corner of the column (indicated by a dotted line W in FIG. 17A). In either case, as shown in FIG. 17B, the upper and lower diaphragms 2 are usually welded and connected by vertical stiffeners 4, and the vertical stiffeners 4 are welded to the center portions of the respective column surfaces to reinforce the diaphragm 2. . Then, the flange portion 3b of the H-beam 3 and the diaphragm 2,
And the beam web part 3a and the vertical stiffener 4 are connected by the connection plate 5 and the bolt 6, respectively.

[0004]

In the conventional outer diaphragm system, when a vertical bending moment M acts on a beam as shown in FIG. 17B, the bending moment M is applied to the column through the vertical stiffener 4. This acts as a compressive tensile stress on the surface, and local buckling B as shown in FIG. In order to increase the resistance to the local buckling B, advanced construction technology such as joining the diaphragm 2 and the column surface by complete penetration welding is required, which has been a problem in terms of construction period and construction cost. .

An object of the present invention is to provide a beam-column joint structure in which the construction period is short, the construction cost is low, and local buckling does not easily occur in the rectangular steel tubular column.

[0006]

In order to achieve the above-mentioned object, the present invention provides a method in which a pair of upper and lower outer diaphragms which are welded perpendicularly to a column surface of a rectangular steel tubular column are vertically interposed between the upper and lower ends. A connecting plate whose ends are fixed is fixed, and the ends of a pair of upper and lower outer diaphragms are connected by abutting the upper and lower flange ends of the H-shaped steel beam, and the connecting plate and the web of the steel beam. It is characterized in that the parts are connected by butting.

[0007] The connecting plate here is a steel plate such as a vertically long strip, and is connected between the distal ends of a pair of upper and lower outer diaphragms to reinforce the distal ends of the pair of upper and lower outer diaphragms. . In addition, by connecting the connecting plate to the web portion of the steel beam, the stress of the web portion is transmitted from the connecting plate to the outer diaphragm, so that the joining strength of the beam-column joint is increased and the stress transmission is improved.

Further, in the present invention, the pair of upper and lower outer diaphragms is composed of two divided diaphragms which are divided into two in the width direction of one pillar surface of the rectangular steel pipe column. It is desirable to insert and fix the upper and lower ends of the connecting plate at slit intervals formed by opposing the portions at predetermined slit intervals in order to facilitate the work of attaching the connecting plate to the outer diaphragm.

Further, in the present invention, it is advantageous to connect the connecting plate and the steel beam with a high strength bolt so that the connecting plate and the web portion of the steel beam are connected to each other with a high-strength bolt. It is.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIGS. 1A and 1B show a joint structure which is a minimum unit of a beam-column joint structure. One steel beam 3 is provided on one column surface 1 a of a steel tube column 1 by an outer diaphragm 22. They are joined via a total of four divided diaphragms 23, 23, 24, 24 of the same shape, up, down, left and right. However, such a unit joint structure is rarely actually constructed, and usually, as will be described later, the steel pipe column 1
A plurality of steel beams 3 are joined to the plurality of column surfaces 1a. A major feature of the present invention is that one connecting plate 30 is fixed between the distal ends of the left and right divided diaphragms 23 and 24, and the web portion 3a of the steel beam 3 is connected to the connecting plate 30. It is.

More specifically, the outer diaphragm 22 is a horizontal steel plate orthogonal to one column surface 1a of the rectangular steel tube column 1,
The outer diaphragm 22 is, for example, shown in FIGS.
The two left and right divided diaphragms 23 and 24 equally divided into two in the width direction of one column surface 1a of the steel pipe column 1 as shown in FIG.
And a pair of left and right divided diaphragms 23, 2
The end of the flange portion 3 b of one steel beam 3 is connected to the tip of the steel beam 4. The pair of left and right divided diaphragms 23 and 24 is a line-symmetrical shape equally divided left and right from the center line of one columnar surface 1a of the square steel tubular column 1, and is between one columnar surface 1a and each of the adjacent columnar surfaces 1a. L-shaped mounting seats 23a and 24a fitted near the corner 1c of the
beam joints 23b, 24 extending from one side of a, 24a
b. One of the divided diaphragms 23 has its L-shaped mounting seat 23a substantially half the width of one pillar surface 1a of the rectangular steel tubular column 1 and another one pillar surface 1a adjacent to the one pillar surface 1a.
For example, a partial cross section A in FIG.
B, and the L-shaped mounting seat 23
FIG. 12A shows the corner concave surface of FIG.
Are separated without welding as shown in the partial section C of FIG.
The partial cross section A in FIG. 12 shows an I-shaped fillet weld, and the partial cross section B in FIG. 12 shows a K-type fillet weld, but the present invention is not limited to these forms.

In the same manner as the above-mentioned one divided diaphragm 23, the other divided diaphragm 24 is also welded to the rectangular steel tubular column 1 at the same height as the one divided diaphragm 23.
The left and right split diaphragms 23 and 24 are connected to the square steel tube column 1
When they are horizontally welded to each other at the same height, the divided surface portions 23c and 24c of the divided diaphragms 23 and 24 oppose each other.
The slits g having a predetermined width are positively formed between them, and the divided diaphragms are not directly welded to each other. FIG.
When the steel beam 3 made of H-section steel is joined to the distal ends of the pair of left and right divided diaphragms 23 and 24, the bending moment and the shearing force of the beam load applied to the divided diaphragms 23 and 24 from the steel beam 3 are L-shaped. It is applied to the column surface 1a of the rectangular steel tube column 1 parallel to the load direction via the mounting seats 23a and 24a.
The strength and load resistance to the shearing force applied to the columnar surface 1a parallel to the beam load direction are highly stable by welding the L-shaped mounting seats 23a and 24a to the columnar surface 1a, and are always high withstand. Loadability is ensured. Also, L-shaped mounting seats 23a, 24
a is welded to only approximately half the width direction of the columnar surface 1a in a direction parallel to the beam load direction, thereby ensuring a sufficiently high load resistance and securing the L-shaped mounting seats 23a and 24b. Is set to be only about half the length in the width direction of one columnar surface 1a, an empty space without an outer diaphragm is secured on the columnar surface 1a.
Further, by separating the concave concave surfaces of the L-shaped mounting seat portions 23a and 24a without welding to the corner portion 1c of the square steel tubular column 1, the beam load is not applied to the corner portion 1c, and the load is concentrated on the column corner portion. Breakage such as generation of cracks is avoided beforehand, and the strength of the weld between the column diaphragms is stabilized.

If one beam connecting outer diaphragm 22 is divided into two as described above, about half of the outer surface of the steel tube column 1 on the side opposite to the outer diaphragm 22 is provided with a projecting member such as an outer diaphragm. Since there is no flat empty space in the pillar surface, when the outer diaphragm 22 is factory-welded to and transported to the steel pipe column 1, the empty space is used to improve the efficiency of transporting the steel pipe column. Further, if the thickness of the outer diaphragm 22 is increased to reduce the size, the transportation efficiency is further improved. In addition, the divided outer diaphragm 22 for joining one steel beam 3 is formed only on a half of the outer periphery of the square steel tubular column 1, so that the entire size and material can be reduced. Become. Furthermore, the inner surfaces of the divided diaphragms 23 and 24 and the square steel tube column 1 are formed by fitting the two divided diaphragms 23 and 24 to the square steel tube column 1 so as to face each other at a predetermined slit interval g. Some relative dimensional errors in the outer circumference of the rectangular steel pipe are absorbed by the slit interval g, and it becomes easy to fit and weld the pair of divided diaphragms 23 and 24 to the outer circumference of the square steel tubular column 1 without play.

The pair of left and right divided diaphragms 23,
24, the width of the slit interval g formed between the tip portions is 1
The thickness is set to about the thickness of the connecting plates 30, and FIG.
(B) As shown in FIG.
The upper and lower ends of the connecting plate 30 are fitted into the second slit interval g and fixed by welding. The fixing of the connecting plate 30 reinforces the distal end portions of the pair of upper and lower outer diaphragms 22, makes it difficult for the outer diaphragm 22 to be deformed even when an external force acts on the outer tube 22 at the time of conveying the steel tube column, and improves the workability of conveying the steel tube column.

The tip of each of the divided diaphragms 23 and 24 of the pair of upper and lower outer diaphragms 22 and the flange 3 of the steel beam 3
b, the both ends are connected to a pair of upper and lower cover plates 41 and 42 with a plurality of high-strength bolts 50, as shown in FIG. 1, for example, and connected to the end of the web portion 3a of the steel beam 3. The plates 30 are abutted and connected to a pair of left and right web joint plates 61 with a plurality of high strength bolts 70. The cover plates 41 and 42 also serve as reinforcing plates for the bending moment of the flange 3 b of the steel beam 3, and
It is desirable to use a steel plate having a higher strength than b. By connecting the web portion 3a of the steel beam 3 to the connecting plate 30 fixed to the pair of upper and lower outer diaphragms 22, web portion stress is transmitted from the connecting plate 30 to the outer diaphragm 22 → the box-shaped steel pipe column 1, The joint strength of the beam-column joint structure is increased, and the stress transmission performance is improved. Outer diaphragm 22 of connecting plate 30
The fixing of the outer diaphragm 22 can be easily and reliably performed by using the slit interval g that is positively formed by dividing the outer diaphragm 22 into two parts.

When the upper and lower ends of the connecting plate 30 are projected from the pair of upper and lower outer diaphragms 22, as shown in FIG. 3, two cover plates 41 are arranged on both sides of the projected end. I do. When the upper and lower ends of the connecting plate 30 do not protrude from the pair of upper and lower outer diaphragms 22 as shown in FIG. 4, the cover plate 41 may be made of a single steel plate as shown in FIG.

In the case where two steel beams 3 are joined to the square steel tube column 1 with a step, for example, as shown by a chain line in FIG. 22 and the same split-type outer diaphragm 22 'are welded with a step to each other to form a pair of outer diaphragms 22, 2 respectively.
It is possible to fix the connecting plates 30 and 30 'to the tip of 2' and join the two steel beams 3 and 3 'with steps. In this case, the outer diaphragm 2 on the outer surface of the square steel tubular column 1
2 and the opposite side of the other outer diaphragm 22 ′ are flat surfaces of empty spaces without overhang members,
Each outer diaphragm 22, 22 'is connected to the mating connecting plate 30,
Both can be easily attached to the steel pipe column 1 without being interfered with by 30 ', thereby facilitating the design of a stepped steel beam joint.

The column-to-beam joint structure of the embodiment shown in FIG. 6 joins two steel beams 3, 3 in the orthogonal direction at the same height to a rectangular steel tube column 1, and in this case, the outer diaphragm 2
2 is divided into three divided diaphragms 23, 24 and 25 having a shape as shown in FIG. Two of the three divided diaphragms 23 and 24 have the same shape as that of FIG. 1, and the other one corresponds to the two divided diaphragms 23 and 24 integrated back to back. This one divided diaphragm 25 is horizontally fitted to one corner 1c of the rectangular steel tube column 1 and partially fillet welded, and the other divided diaphragms 23 and 24 are horizontally fillet welded on both sides thereof. You. A slit interval g is formed between the distal end of one of the divided diaphragms 23 and one distal end of the divided diaphragm 25 opposed to the distal end, and the connecting plate 30 is inserted and fixed in the slit interval g to be connected. The plate 30 is joined to one steel beam 3. A slit interval g is formed between the distal end of the other divided diaphragm 24 and the other distal end of the divided diaphragm 25 facing this distal end, and another one is provided on the connecting plate 30 fixed at the slit interval g. Steel beams 3 are joined. FIG. 8 shows a specific structure of such a steel beam joint.

The beam-to-column joint structure of the embodiment shown in FIG. 7 is to join three steel beams 3 at the same height to a rectangular steel tube column 1 in three orthogonal directions. In this case, an outer diaphragm 22 is provided. Are two divided diaphragms 23 and 24 having the same shape.
And another two divided diaphragms 25 having the same shape.
Divided into a total of four. Two of the four divided diaphragms 23 and 24 have the same shape as in FIG. 1, and the remaining two divided diaphragms 25 and 25 have the same shape as the divided diaphragm 25 in FIG. These two divided diaphragms 2
5 and 25 are horizontally fitted to two corner portions 1c on both sides of one column surface 1a of the rectangular steel tubular column 1, and partially fillet-welded,
The two divided diaphragms 23 and 24 are fitted to the remaining two corners 1c of the rectangular steel tube column 1 and partially fillet welded. The leading ends of the two divided diaphragms 23 and 24 and the two divided diaphragms 25 and 25 facing the leading ends, respectively.
A slit interval g is formed between the outer distal ends of the steel plates. The steel beam 3 is joined to the connecting plate 30 fixed at the slit interval g, and a slit formed between the inner distal ends of the two divided diaphragms 25, 25. The connecting plate 30 is fixed at the interval g, and another steel beam 3 is joined to the connecting plate 30. FIG. 9 shows a specific structure of such a steel beam joint.

The beam-column joint structure of the embodiment shown in FIGS. 10A and 10B is to join four steel beams 3,... At the same height to a rectangular steel tubular column 1 in four orthogonal directions. The outer diaphragm 22 in this case is divided into four divided diaphragms 25 having the same shape. 4 divided diaphragms 2 each
.. Have the same shape as the divided diaphragm 25 in FIGS. 6 and 7. The four divided diaphragms 25 are horizontally fitted to the four corners of the square steel tubular column 1 and partially welded with fillets. A slit interval g,... Is formed between two adjacent tips of the four divided diaphragms 25,..., And the connecting plates 30, fixed at the slit intervals g,.
, A total of four steel beams 3, ... are joined. FIGS. 11A and 11B show a specific structure of such a steel beam joint.

The beam-to-column joint structure of the embodiment shown in FIGS. 14 and 15 is to join the steel beam 3 eccentrically to the square steel tubular column 1. FIG. 14 shows one example of joining one steel beam 3.
The two outer diaphragms 22 into narrow dividing diaphragms 2
It is divided into two pieces, 3 'and a wide dividing diaphragm 24'. A narrow dividing diaphragm 23 'and a wide dividing diaphragm 24' having the same height and a narrow width are welded to one column surface 1a of the rectangular steel tube column 1, and a slit interval g formed therebetween is set to the center line of the column surface 1a. To narrow dividing diaphragm 2
By shifting the connecting plate 30 fixed to the slit gap g to the center web portion 3a of one steel beam 3 by shifting to the 3 'side, the steel beam 3 is eccentrically joined to the square steel tubular column 1 and joined. I do.

FIG. 15 shows two steel beams 3,
3 are joined at right angles, and the outer diaphragm 22 in this case is divided into three divided diaphragms 23 ′, 23 ′, 2 ′.
It is divided into 5 '. Two split diaphragms 23 ', 2
3 'has the same shape as the narrow divided diaphragm 23' of FIG. 14, and the remaining one divided diaphragm 25 'has the same shape as that of FIG.
Corresponds to the one obtained by integrating two wide divided diaphragms 24 ′ back to back. The one divided diaphragm 25 'is fitted to one corner 1c of the rectangular steel tubular column 1 and partially welded with a fillet, and two divided diaphragms 23' and 23 'are arranged on both sides thereof. Each of the orthogonal steel beams 3, 3 is eccentrically joined to the square steel tubular column 1.

In the beam-to-column joint structure shown in FIGS. 14 and 15, it is possible to shorten the protruding length of the narrow divided diaphragms 23 ', 23' from the column surface of the rectangular steel tube column 1, so that the rectangular steel tube column is used. The size of the diaphragm projection on the column surface on the side where the beam 1 is not joined and the beam is eccentric can be reduced, and the degree of freedom in design such as the external dimensions of the steel building increases.

In each of the embodiments described above, the outer diaphragm is divided into two parts, and the connecting plate is inserted and fixed at the slit interval formed between the divided diaphragms. The connecting plate may be fixed by welding, bolting, or the like as a single-piece steel plate. Alternatively, a notch into which the connecting plate is fitted may be formed at the tip of the outer diaphragm made of a single steel plate, and the notch may be used to position and fix the connecting plate. Further, the steel beam has been described as an H-beam single beam structure, but may be a double beam or an assembled beam.

Next, a modification of the present invention will be described with reference to FIG. FIGS. 16 (A) and 16 (B) show a connection plate 30a (30b) for connecting the upper and lower divided diaphragms 25 to each other, which is slightly wider, and which is fillet welded to the center of the side surface of the rectangular steel tubular column 1. Other parts are basically the same as those in FIG. The upper and lower corners of the connecting plate 30a on the steel pipe column 1 side are shown in FIG.
It may be cut out in a U-shape as shown on the left side, so that the intersection between the diaphragm 25 and the fillet welded portion between the steel pipe column 1 can be avoided, and the workability of welding can be improved. FIG.
(B) The right side shows the connecting plate 30b which is not notched in a U-shape.
The upper and lower ends of the connecting plate 30a (30b) are
5, and both upper and lower ends may be slightly projected from the diaphragm 25 as shown on the left side of FIG.

[0026]

According to the present invention, the connecting plate is fixed between the distal ends of the outer diaphragms for joining the steel beam to the square steel tubular column,
Since this connecting plate is connected to the web portion of the steel beam, the stress from the beam web portion is not directly transmitted to the front of the rectangular steel tubular column as in the conventional outer diaphragm system, but the outer diaphragm is connected via the connecting plate. To the side of the square tubular column,
In addition, the stress from the beam flange can also be transmitted to the side of the square steel tube column instead of the front, and the shear resistance on the side of the square steel tube column has much more margin than the tensile and compression resistance at the front of the square steel tube column. Thus, the web stress or the flange stress can be reliably supported, and local buckling at the front of the square steel tubular column can be effectively prevented or suppressed. Further, since the present invention supports the web stress or the flange stress by the shear resistance between the rectangular steel pipe column and the outer diaphragm, the welding strength condition of the outer diaphragm to the rectangular steel pipe column can be relaxed, and the conventional high strength welding can be performed. Instead of the complete penetration welding, it is possible to employ a welding method that is advantageous in terms of the construction period and construction cost, such as fillet welding.

[Brief description of the drawings]

FIG. 1A is a plan view showing a first embodiment of the present invention, and FIG. 1B is a side view thereof.

2A is a plan view of an outer diaphragm in the joint structure of the embodiment of FIG. 1, and FIG. 2B is a side view thereof.

3A is a plan view when a connecting plate is connected to the outer diaphragm in FIG. 2, and FIG. 3B is a side view thereof.

FIG. 4 is a side view showing a modification of the connecting plate of the embodiment shown in FIG. 3;

FIG. 5 is a plan view when a steel beam is joined to the joining structure of FIG. 4;

FIG. 6 is a plan view of an outer diaphragm showing a second embodiment of the present invention.

FIG. 7 is a plan view of an outer diaphragm showing a third embodiment of the present invention.

FIG. 8 is a plan view when a steel beam is joined to the joining structure of FIG. 6;

FIG. 9 is a plan view when a steel beam is joined to the joining structure of FIG. 7;

FIG. 10A is a plan view of an outer diaphragm showing a fourth embodiment of the present invention, and FIG. 10B is a side view thereof.

11A is a plan view when a steel beam is joined to the joint structure of FIG. 10, and FIG. 11B is a side view thereof.

FIG. 12 is an exploded plan view of a divided outer diaphragm in the joint structure of FIG. 1;

FIG. 13 is an exploded plan view of a divided outer diaphragm in the joint structure of FIG. 6;

FIG. 14 is a plan view of an outer diaphragm showing a fifth embodiment of the present invention.

FIG. 15 is a plan view of an outer diaphragm showing a sixth embodiment of the present invention.

16A and 16B are a plan view and a side view showing a modification of the joint structure of the present invention.

FIG. 17 (A) is a plan view of a conventional column-beam joint structure using an outer diaphragm system, FIG. 17 (B) is a side view taken along line bb of FIG.
(C) is a sectional view of a locally buckled column.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Square steel pipe column 1a Column surface 1c Corner part 3 Steel beam 3a Web part 3b Flange part 22 Divided outer diaphragm 23,24,25 Divided diaphragm g Slit interval 30 Connection plate 61 Joint plate 70 High strength bolt

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Ryuichi Matsuo 2-26 Tsumon Nishiguchicho, Nishinomiya City, Hyogo Prefecture Arai Gumi Co., Ltd. (72) Inventor Takeyuki Ochi 947-6 Yuge, Tatsutacho, Kumamoto F-term (reference) 2E125 AA03 AA13 AB01 AB16 AC15 AC16 AG03 AG04 AG12 AG41 BB01 BB02 BB04 BB09 BB22 BC09 BD01 BE05 BE08 BF04 CA05 CA06 CA14 EA00

Claims (3)

[Claims] 1. A connecting plate having upper and lower ends fixed at the upper and lower ends between a pair of upper and lower outer diaphragms which are welded perpendicularly to a column surface of a rectangular steel pipe column. A rectangular shape in which a pair of upper and lower outer diaphragms are connected by abutting ends of upper and lower flanges of an H-shaped steel beam, and connecting the connection plate and a web portion of the steel beam. Joint structure between steel pipe columns and steel beams. 2. A pair of upper and lower outer diaphragms are constituted by two divided diaphragms obtained by dividing a pair of outer diaphragms into two in the width direction of one pillar surface of a rectangular steel pipe column, and the leading end of each of the two divided diaphragms has a predetermined slit interval. The joint structure between a rectangular steel pipe column and a steel beam according to claim 1, wherein upper and lower ends of the connection plate are fitted and fixed in the slit intervals formed so as to face each other. 3. The connection plate and the web portion of the steel beam are connected by attaching a joint plate to both surfaces of the connection plate and the web portion of the steel beam and bolting with high strength bolts. 1
Or the joining structure of a square steel pipe column and a steel beam as described in 2.