JP2000248617A - Connection structure of steel structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a connection structure effective for reducing an increase in the manufacturing cost of connection members and a decline in the efficiency of the execution of works after securing the stiffness of the structure and preventing sudden breakage due to fragility fracture in the connection of a column and beam members. SOLUTION: The end of the upper flange 15fa of a beam member 15 is butted against and welded to the end of a diaphragm 12 mounted to a column 11 by welding, the lower flange 15fb of the beam member 15 is mounted on the top of brackets 13 mounted to the column 11 by welding, and then the brackets 13 and the lower flange 15fb are joined by lap fillet welding. Furthermore, gusset plates 14 are mounted to the column 11 by welding, and the web 15w of the beam member 15 is connected to the gusset plates 14 with bolts.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint structure of a steel structure for joining a beam member made of H-section steel to a column.

[0002]

2. Description of the Related Art Many methods using a through-diaphragm or an outer diaphragm have been employed for joining a column and a beam member in a steel structure. FIG. 7 is a view showing a conventional through-diaphragm method, in which a hollow pillar 51 is cut at two places.
The two through-diaphragms 52 and 53 are arranged at the cut portion, and the cut portion of the column 51 and the diaphragms 52 and 53 are again formed.
Then, the beam member 54 is joined to the outer periphery of the diaphragms 52 and 53 by butt welding. In the case of the outer diaphragm method, the method of welding and joining the beam members is basically the same.

[0003] Welding as a means of joining steel materials has gained considerable reliability in terms of strength as the technology has advanced. However, in the case of the joint structure as shown in FIG. 7, it has been pointed out that there is a risk of brittle fracture due to stress concentration in the scalloped portion 55. This scalloped part 5
5 is upper and lower flanges 54fa, 54fb of the beam member 54
In order to weld the end faces of the upper and lower diaphragms 52 and 53 respectively, the upper and lower ends of the web 54w are partially cut away.

According to the results of a survey on the destruction of a steel structure damaged by the Great Hanshin Earthquake, most of the damage at the joint between the column and the beam member was caused by welding at the lower flange side of the beam member end. Fracture and brittle fracture, and it is clear that brittle fracture caused by scallops is particularly large. The upper flange side was protected by a concrete slab on the floor, and no fracture occurred except for the defective weld. When the flange end faces of the beam members are joined to the column by butt welding, the joints have high strength against pulling, but low strength against shearing, resulting in insufficient strength against shaking during an earthquake and fracture from the lower flange side Is considered to occur.

[0005]

As joint structures for eliminating the problem of stress concentration due to scallops, there are joint structures described in JP-A-6-313334 and JP-A-6-344135. JP-A-6-313334
In the joint structure described in the publication, a flange joint plate is pre-attached to the beam member, the web joint plate attached to the column at the construction site is tightened, and then the upper and lower flange joint plates are welded on-site to the column. It is a joint structure. The joint structure described in Japanese Patent Application Laid-Open No. 6-344135 discloses a joint structure in which a groove is provided at a joint end face of a flange of a beam member and a web, and a fillet portion of the flange at the joint end face and a fillet portion of the web are non-scallop parts. It is.

According to the joining structure described in the above publication,
Since it is not necessary to provide a scalloped portion in joining the column and the flange of the beam member, the problem of stress concentration due to the conventional scallops can be eliminated. However, in the joining structure described in the above-mentioned publication, welding of the flange of the beam member to the column body is butt welding same as the conventional method,
The above-mentioned problem that the strength of the joint, particularly the strength against shearing, is low and the lower flange side is easily broken at the time of an earthquake or the like cannot be solved.

[0007] The present invention provides a joint structure that is effective in preventing breakage due to brittle fracture on the lower flange side of the end of a beam member while maintaining good workability in joining the column and the beam member. The purpose is to do.

[0008]

SUMMARY OF THE INVENTION The present invention relates to a joint structure of a steel structure for joining a beam member made of an H-section steel to a column, wherein a lower flange of an upper flange and a lower flange of the beam member is provided. The lower surface of the end of the lower flange and the upper surface of the reinforcing member are brought into contact with each other and are overlap-filled, and the reinforcing member is joined to the column by welding directly or via a diaphragm to the column. The upper flange of the beam member, the upper surface of the end of the same flange and the lower surface of the reinforcing member are brought into contact with each other and fillet welding is performed, and the reinforcing member is attached to the column directly or by welding via a diaphragm, Alternatively, the end face of the flange and the end face of the diaphragm attached to the column are butt-welded and joined to the column.

In such a joint structure, when a load greater than the design load is applied to the joint, the joint on the upper flange side of the beam member is protected by a concrete slab or the like on the floor. Unless there is no break, the joint on the lower flange side of the beam member is a fillet welded joint with the reinforcing material and the lower flange overlapped,
It has a higher proof stress than butt welding and is less likely to break due to brittle fracture.

The cross-sectional shape of the reinforcing member is not particularly limited, and a steel plate or a shaped steel can be used. In the case of a shaped steel, for example, when a shaped steel having a T-shaped cross section is used, there is an advantage that the stability of the posture when the reinforcing material is attached to the column is good. The section steel having this T-shaped cross section is H
It can be manufactured by cutting a web of shaped steel. The strength of the reinforcing material against the load applied to the weld can be increased by increasing the cross-sectional dimensions such as the thickness of the reinforcing material. By making up for the above, it is possible to obtain a joint structure having sufficient welding strength at the upper and lower joints.

When the reinforcing material and the lower flange are overlapped with each other and are attached to the column, the reinforcing material is attached to the column directly or via a diaphragm at the construction site by welding, and the reinforcing material is attached to the end of the lower flange. Welding method by placing the parts and overlapping fillet welding, or welding the reinforcing material to the lower flange in advance by factory welding and attaching the reinforcing material to the column directly or through the diaphragm at the construction site by welding be able to. The fillet welding of the reinforcing material and the upper flange can be carried out by welding the reinforcing material to the upper flange in advance by factory welding, and attaching the reinforcing material to the column directly or through the diaphragm at the construction site by welding. .

Here, the inner diaphragm can be attached inside the column at the position where the reinforcing member is attached. Thereby, the rigidity of the reinforcing material mounting position is further reinforced.
The inner diaphragm can be attached to the inside of the column by welding before attaching the through diaphragm by using a diaphragm that joins the upper flanges of the beam members as a through diaphragm. In addition, an internal reinforcing member formed in a cross shape by welding can be attached to the column between the inner diaphragm and the through diaphragm. Since such an inner diaphragm, a through diaphragm, and a reinforcing material can be attached by factory welding, workability at a construction site is improved, and rigidity of a joint is increased.

In the joint structure of a steel structure according to the present invention, the column and the lower flange of the beam member may be connected to an upper surface of a projecting portion of a lower diaphragm attached to the column and a lower surface of an end of the lower flange. And a joining structure in which the pillar and the upper flange of the beam member are joined by butt-welding the end face of the diaphragm attached to the pillar and the end face of the upper flange. It may be. Here, a diaphragm can be formed through the upper diaphragm and the lower diaphragm.

[0014] Also in this joint structure, when a load greater than the design load is applied to the joint, the joint on the upper flange side of the beam member does not break unless there is poor welding, and the lower flange side does not. Is joined by fillet welding with the overhanging portion of the lower diaphragm and the lower flange overlapped, so that breakage due to brittle fracture hardly occurs. In particular,
In the case of this joint structure, the lower flange is overlapped and fillet welded is not a reinforcement attached to the column, but a diaphragm with an overhang, so the rigidity of the joint is large,
Suitable for the joint structure of beam members with large flange height.

By passing the upper diaphragm and the lower diaphragm together to form a diaphragm, the upper and lower diaphragms can be attached by factory welding, thereby improving the workability at the construction site and increasing the rigidity of the joint.

In the joint structure according to the present invention, the fillet welding is carried out by overlapping the reinforcing member or the lower diaphragm with both sides of the upper surface of the projecting portion at a predetermined interval from the side edges of the flange of the beam member. A weir plate that blocks the flow of molten metal can be provided.

In fillet welding, the "throat thickness" and "leg length" of the deposited metal are important requirements that affect the quality of the weld. Particularly in welding at a construction site, the welding posture is unstable and, as in the case of the joint structure of the present invention, the gap between the side edge of the flange of the beam member and the side edge of the reinforcing member or the lower diaphragm is narrow, In addition, under the condition that there is nothing below the side edge of the reinforcing member or the lower diaphragm, the molten metal flows down from the side edge of the reinforcing member or the lower diaphragm, and it is difficult to obtain a normal shape of the deposited metal. Therefore, by providing a weir plate that blocks the flow of the molten metal, a good weld can be obtained stably even under unstable conditions.

Further, in the joint structure of the present invention, it is possible to reinforce the flange of the beam member or the projecting portion of the lower diaphragm near the joint with the pillar by reinforcing the carbon fiber. By attaching and reinforcing the carbon fiber, the proof stress of the joint on the flange side can be further increased.

In the joint structure of the present invention, the web of the beam member is desirably attached with a gusset plate between upper and lower diaphragms or upper and lower reinforcing members of the column by welding and joined to the gusset plate by bolts. Thereby, workability can be improved and a joint structure having higher strength can be obtained.

[0020]

FIG. 1 is a perspective view showing a joint structure according to a first embodiment of the present invention, FIG. 2 is a perspective view of a reinforcing member in the joint structure of FIG. 1, and FIG. 3 is a lower flange of a beam member. It is a perspective view which shows the overlap fillet welding of a reinforcing material.

In FIG. 1, reference numeral 11 denotes a hollow columnar body having a square cross section, 12 denotes a diaphragm, 13 denotes a bracket as a reinforcing material, 14 denotes a gusset plate, and W denotes a welded portion. These diaphragm 12, bracket 13 and gusset The plate 14 is fixed to the column 11 by welding.

The diaphragm 12 is a joint member having a substantially square ring shape with an inner size larger than the outer dimension of the column 11 by about 2 mm, and the diaphragm 12 is inserted through the column 11
The outer surface of the column 11 and the inside of the diaphragm 12 are welded to fix the diaphragm 12 to the column 11. The end of the upper flange 15fa of the beam member 15 made of H-section steel is joined to the outer end surface of the diaphragm 12 by butt welding.

As shown in FIG.
The joining member is cut into a shape shown in FIG. 1 and has a T-shaped cross section. The outer surface of the column 11 and the end surface of the bracket 13 are welded to fix the bracket 13 to the column 11. Bracket 1
3 has a T-shape, so that the posture of the bracket 13 when welding the bracket 13 to the column 11 is good. The end of the lower flange 15fb of the beam member 15 is placed on the upper surface of the bracket 13, and as shown in FIG. 3, the bracket 13 and the lower flange 15fb are overlapped and fillet welded.

In this embodiment, the lower flange 15 of the beam member 15 is provided on both side edges of the upper surface of the bracket 13.
A weir plate 13a is provided at a fixed interval (same as the thickness of the lower flange 15fb) from the side edge of fb to prevent the flow of the molten metal at the time of overlapping fillet welding. By providing the weir plate 13a, the molten metal does not flow down from the side edge of the bracket 13 during welding, and a normal shape of the deposited metal can be obtained.

Further, in the present embodiment, the beam member 15
In order to further increase the proof stress of the joint on the lower flange 15fb side, carbon fiber (not shown) is attached to the overlapping surface of the lower flange 15fb with the bracket 13 for reinforcement.

The gusset plate 14 is a joining member in which a bolt hole 16 is formed in one plate material, and the outer surface of the column 11 and the end surface of the gusset plate 14 are welded to fix the gusset plate 14 to the column 11. The web 15 w of the beam member 15 is bolted to the gusset plate 14.

Since the joint structure of the present embodiment is configured as described above, when a load greater than the design load is applied to the joint, the joint on the upper flange 15fa side of the beam member 15 is connected to the concrete slab of the floor. Since it is protected by such as, there is no break unless there is poor welding, and since the joint on the lower flange 15fb side is a joint obtained by overlapping the bracket 13 and the lower flange 15fb and filling the fillet, The structure has higher proof stress than butt welding and is less likely to break due to brittle fracture.

FIG. 4 is a view showing a cross-sectional structure of a joint according to a second embodiment of the present invention. This joint is connected to pillar 11
This is an example in which a medium-sized beam member 15 is joined to one side and a large-sized beam member 25 is joined to the other side.

In this embodiment, the joining structure of the beam member 15 is such that the diaphragm 22 joining the upper flange 15fa of the beam member 15 is formed as the diaphragm 22, and the inner diaphragm 27 is provided inside the column 11 at the position where the bracket 13 is attached. It has an attached structure. Inner diaphragm 27
Is attached, the rigidity of the mounting position of the bracket 13 is reinforced. The inner diaphragm 27 is attached to the inside of the column 11 by welding before the through diaphragm 22 is attached.

The joint structure of the beam member 25 is such that the upper flange 25 of the beam member 25 is attached to the end face of the upper through-diaphragm 22.
fa by welding the end surfaces of the beam members 2a and 2b to the upper surface of the projecting portion 28a of the lower through diaphragm 28.
5, the lower flange 25fb is placed, and the overhang portion 28a and the lower flange 25fb are joined by fillet welding. The web 25w is joined by bolts to a gusset plate 24 attached to the column 11 by welding. In the column 11 between the inner diaphragm 27 and the through diaphragm 22, a reinforcing member 29 formed in a cross shape by welding as shown in FIG. This joining structure is suitable for joining a beam member having a large flange height and a high rigidity at a joining portion.

FIG. 5 is a perspective view showing a joint structure according to a third embodiment of the present invention. In the figure, a column 11, a diaphragm 12, a gusset plate 14, and a beam member 1 are shown.
5 is the same as in the first embodiment. In the joining structure of the present embodiment, the joining of the upper flange 15fa and the web 15w of the beam member 15 to the column 11 is the same as that of the first embodiment, and the joining of the lower flange 15fb to the column 11 is as follows. Lower flange 15fb beforehand by factory welding
A plate 33 as a reinforcing material is overlapped on the end of the column and attached by fillet welding, and the plate 33 is attached to the column 11 by welding at the construction site.

In this embodiment, as in the case of the first embodiment, the joint on the lower flange 15fb side is formed by joining the plate 33 as a reinforcing material and the lower flange 15fb by fillet welding. Therefore, the structure has a higher proof stress than butt welding and is less likely to be broken by brittle fracture.

FIGS. 6A and 6B are views showing a joint structure according to a fourth embodiment of the present invention, wherein FIG. 6A is a front view, and FIG.
FIG. This embodiment is different from the third embodiment in that the lower flange 15fb of the beam member 15 is
3. The attachment of the upper flange 15fa to the column body through the through diaphragm 42 and the joining of the upper flange 15fa to the column body are performed by bringing the upper surface of the end of the upper flange 15fa into contact with the lower surface of the plate 43 as a reinforcing material. To fill the column 1 through the plate 43 and the diaphragm 22.
1 was attached. The fillet welding of the upper flange 15fa and the plate 43 is performed by factory welding, and the plate 43 is attached to the through diaphragm 22 by welding at a construction site. In the present embodiment, FIG.
As shown in FIG. 5, the joint strength between the upper and lower flanges 15fa, 15fb and the plates 33, 43 is increased by performing plug welding Wp together with the overlap fillet welding between the upper and lower flanges 15fa, 15fb and the plates 33, 43.

The joining structure of the present invention is not limited to the above embodiment, and the arrangement of the beam members corresponds to any one of the middle pillar, the side pillar, and the corner pillar in the steel structure. It can be arbitrarily determined according to the design conditions such as

[0035]

According to the present invention, the following effects can be obtained.

(1) At least the lower flange of the upper and lower flanges of the beam member is overlap-filled welded by contacting the lower surface of the flange end with the upper surface of the reinforcing material, and the reinforcing material is directly or via a diaphragm. By connecting to the column by attaching by welding, the proof strength is increased compared to conventional butt welding, and even when a load exceeding the design load is applied to the joint, the upper flange side of the beam member is joined Since the part is protected by a concrete slab on the floor, it will not break unless there is poor welding,
Breakage of the joint due to brittle fracture is less likely to occur.

(2) Similarly, for the upper flange,
By joining the upper surface of the flange end and the lower surface of the reinforcing material by overlapping fillet welding and attaching the reinforcing material to the column directly or through a diaphragm by welding, a high joining strength is obtained at the joint on the upper flange side. can get.

(3) The same effect as described above can be obtained also by joining the lower flange of the beam member to the upper surface of the overhanging portion of the lower diaphragm attached to the column by fillet welding. In particular, by forming the upper diaphragm and the lower diaphragm through the diaphragm, the rigidity of the joining portion on the lower flange side can be increased, and a joining structure suitable for joining a beam member having a large flange height can be obtained.

(4) Flow of molten metal at the time of fillet welding at the upper or lower surface of the reinforcing material or on both side edges of the upper surface of the projecting portion of the lower diaphragm with a predetermined interval from the side edge of the flange of the beam member By providing the weir plate for preventing the welding, the molten metal does not flow down from the side edge of the overhanging portion of the reinforcing member or the lower diaphragm at the time of welding, and a good welded portion where no welding defects occur can be obtained.

(5) By strengthening carbon fiber at a portion of the flange of the beam member or the projecting portion of the lower diaphragm close to the joint with the column, reinforcing the joint at the flange can be further enhanced. it can.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a joint structure according to a first embodiment of the present invention.

FIG. 2 is a perspective view of a reinforcing member in the joint structure of FIG.

FIG. 3 is a perspective view showing overlap fillet welding of a lower flange of a beam member and a reinforcing member.

FIG. 4 is a diagram illustrating a cross-sectional structure of a joint according to a second embodiment of the present invention.

FIG. 5 is a perspective view showing a joint structure according to a third embodiment of the present invention.

FIG. 6 is a view showing a joint structure according to a fourth embodiment of the present invention.

FIG. 7 is a perspective view showing an example of a conventional joining structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Pillar 12 Diaphragm 13 Bracket 13a Weir plate 14, 24 Gazette plate 15, 25 Beam member 15fa, 25fa Upper flange 15fb, 25fb Lower flange 15w, 25w Web 16 Bolt hole 22 Through diaphragm 27 Inner diaphragm 28 Through diaphragm 28a Tension diaphragm 28a Plate 42 Through diaphragm 43 Plate W Welded part Wp Plug welding

Continued on front page F term (reference) 2E125 AA04 AA14 AB01 AB16 AC15 AC16 AG57 BA55 BB02 BB13 BB22 BC09 BD01 BE01 BF04 CA05 CA14 CA90 4E081 AA08 AA12 BA40 BA47 CA05 CA07 DA06 DA12 DA30 DA35 YB03 YX03

Claims (4)

[Claims] 1. A joining structure of a steel structure for joining a beam member made of an H-beam to a column, wherein a lower flange of an upper flange and a lower flange of the beam member is connected to an end of the lower flange. The lower surface of the reinforcing member is brought into contact with the upper surface of the reinforcing member by overlapping fillet welding, and the reinforcing member is joined to the column by welding to the column directly or via a diaphragm, and the upper flange of the beam member is The upper surface of the end of the flange and the lower surface of the reinforcing member are brought into contact with each other and are overlap-filled and welded, and the reinforcing member is attached to the column directly or by welding through a diaphragm, or the end surface of the flange and the A joint structure for a steel structure, wherein the end face of a diaphragm attached to a column is joined to the column by butt welding. 2. A joint structure of a steel structure for joining a beam member made of H-section steel to a column, wherein the column and the lower flange of the beam member are connected to a lower diaphragm attached to the column. The upper surface of the overhang portion and the lower surface of the end of the lower flange are brought into contact with each other and joined by fillet welding, and the column and the upper flange of the beam member are connected to the end surface of the diaphragm attached to the column and the upper flange. A joining structure for a steel structure, wherein the joining is performed by butt welding with an end face. 3. The welding at the time of lap fillet welding at a fixed distance from a side edge of a flange of the beam member on an upper surface or a lower surface of the reinforcing member or on both side edges of an upper surface of a projecting portion of the lower diaphragm. The joint structure of a steel structure according to claim 1 or 2, further comprising a weir plate that blocks a flow of metal. 4. The steel structure according to claim 1, wherein a carbon fiber is attached to a portion of the flange of the beam member or a projecting portion of the lower diaphragm near a joint with the column. Joint structure.