JP2708698B2 - Construction method of combined joint of friction joint high strength bolt joint and weld joint - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint using a friction-joined high-strength bolted joint and a welded joint used for a joint of a steel member of a steel structure such as a bridge or a building. The present invention relates to a method for constructing a joint using a friction-joined high-strength bolted joint and a welded joint to reduce the residual stress of the high-strength bolt and to prevent the reduction of the slip strength of the high-strength bolt.

[0002]

2. Description of the Related Art In-situ joints used for steel members of steel structures such as bridges and buildings generally use friction-joined high-strength bolt joints instead of welded joints. In the case of using a welded joint, welding generally requires a long working time, so it is necessary to restrain the erection machine and workers during the welding work, which is uneconomical. In the case of constructing a steel frame while blocking traffic, a long working time has a large effect on social life. Furthermore, when welding is performed on site, it is difficult to prepare a construction environment unlike the case of welding at a factory, and thus there is a problem in quality control.

[0003] On the other hand, when the friction-joined high-strength bolt joint is used alone, the above-mentioned drawbacks are not present, but the linearity of the amount of deformation with respect to the load, that is, the elastic deformation performance is inferior, and the member strength at the joint decreases. There's a problem. FIG. 6 shows a comparison between a friction-joined high-strength bolt joint and a welded joint. In the case of a welded joint, the load and the deformation amount are in a proportional relationship as indicated by a straight line a. In Case of,
As shown by the curve c, when the load becomes large, the deformation becomes extremely large, and it can be seen that the friction-bonded high-strength bolted joint has a smaller load than the welded joint, and therefore has a lower proof stress, when compared with the same deformation.

Therefore, conventionally, when a steel frame is erected on site by using a friction-joined high-strength bolt joint and a weld joint together, the joint is made with a friction-joined high-strength bolt joint enough to support the load at the time of erection. Release the erection machine and workers in a short time, and then apply a welded joint to the joint to reinforce the strength of the friction-joined high-strength bolted joint and counteract the load acting on the main body structure after erection. ing. In this case, the elastic deformation performance of the entire joint is improved as compared with the case of only the friction-joined high-strength bolt joint, and a decrease in the member strength at the joint can be suppressed. FIG. 6 shows a comparison between a joint using a friction-joined high-strength bolted joint and a welded joint and a friction-joined high-strength bolted joint. Although the load and the amount of deformation are proportional to each other as shown by b, it can be seen that the proof stress is larger than in the case of the friction-joined high-strength bolted joint.

[0005] However, there is a problem to be solved when a combined joint of a friction joint high strength bolt joint and a weld joint is used. That is, (1) when the contraction deformation of the base material due to welding heat is restrained by the friction-bonded high-strength bolt joint, stress is generated on the friction-bonded surface of the friction-bonded high-strength bolt joint, and the friction-bonded high-strength bolt joint is generated. There is no allowance for the allowable frictional force that can be applied to the part, and the substantial slip resistance as a high-strength bolt is reduced. (2) Further, when the contraction deformation of the base material due to welding heat is restrained by the friction-joined high-strength bolted joint, residual stress is generated inside the steel member, and there is no room for the allowable stress that can be applied to the base material. In addition, it cannot bear the load when used as a main body structure.

Therefore, in order to solve the above problem (1) in particular, conventionally, high-strength bolts are not tightened in the vicinity of a welded joint where the influence of welding heat is large, and a portion of the joint not affected by welding heat is conventionally not tightened. A method is used in which high-strength bolts are tightened with a design tightening force, and after the welding heat is cooled, the remaining high-strength bolts are tightened with the design tightening force. As a research paper on this method, "Investigation on the binding strength of high-strength web plate bolts associated with on-site welding of steel deck" Katayama Technical Report, Showa 5
Published on August 20, 2009, authors Tetsuya Kojima, Yoshio Yoshida, Yoshihiro Natsuaki, Katayama Iron Works Co., Ltd.

Further, in order to solve the above problem (1) in particular, all of the high-strength bolts for friction joining, which are not affected by heat, in the friction-joining high-strength bolt joints are all designed with a tightening force. Part of the high-strength bolts for friction joining of the heat-affected parts are tightened with the design tightening force.After the welding heat has cooled, the high-strength bolts in the parts affected by the welding heat are removed, and the new high-strength bolts are removed. A method of replacing with a force bolt and tightening with a design tightening force is also used. As a research paper on this method, "Investigation of Impact on Welding and Bolt Joints" published by Tokyo Metropolitan Technical Report, March 1, 1983, author Haruo Takano, Tadashi Kumagai, Koichi Sano, published by Metropolitan Expressway Public Corporation be able to.

Next, in order to solve the above problem (2) in particular, conventionally, the high-strength bolt of the friction-joint high-strength bolt joint is tightened at about 60% of the design tightening force, and the welding heat is cooled. Later, a method of tightening all high-strength bolts with a design tightening force has also been studied. A research paper on this method includes "Experimental Research on Joints Using High-Strength Bolts and Welds", Yokogawa Bridge Technical Report, published on November 1, 1977, author Mitsuhiro Natsume, issuance office, Yokogawa Bridge Co., Ltd. You can name a production place.

[0009]

However, of the above-mentioned methods, high-strength bolts are not tightened in the vicinity of a welded joint where the influence of welding heat is large, and a high-strength bolt which is not affected by welding heat is designed. In the method of tightening the remaining high-strength bolts with the design tightening force after the welding heat cools down, the range of tightening with the design tightening force is small among the high-strength bolts of the friction joining high-strength bolt joint As a result, the joint's proof strength during erection is reduced, and if it is necessary to support a large load during erection, the joint structure must be enlarged.In addition, the number of high-strength bolts after welding increases, and Is complicated.

In the above-mentioned method, all the high-strength bolts of the friction-joined high-strength bolt joint that are not affected by heat are all tightened by the design tightening force. For the bolts, the method of tightening a part with the design tightening force, after the welding heat has cooled, removing the high-strength bolt affected by the welding heat, replacing it with a new high-strength bolt, and tightening with the design tightening force However, if it is necessary to support a large load during installation, the joint structure can be made smaller.However, since high-strength bolts once tightened with the design tightening force cannot be reused, replaced high-strength bolts must be discarded. Must be uneconomical.

Further, in the above method, the high-strength bolts of the friction-joint high-strength bolt joints are tightened to about 60% of the design tightening force, and after the welding heat is cooled, all the high-strength bolts are tightened to the design tightening force. With the method of tightening, no residual stress is generated inside the base material and no stress is generated at the high-strength bolted joints, but the high-strength bolt is installed in a tightened state with about 60% of the design tightening force. When the load at the time is supported, a shear force acts on the shaft portion of the high-strength bolt, and there is a problem that a predetermined axial force cannot be introduced into the high-strength bolt even if the bolt is tightened with the design tightening force after the completion of the erection. The present invention eliminates the concentration of the residual stress of the base material in a joint joint of a friction joint high strength bolt joint and a weld joint used for steel members of steel structures such as bridges and buildings,
An object of the present invention is to provide a combined joint of a friction-joined high-strength bolt joint and a welded joint that does not reduce the slip strength of the high-strength bolt.

[0012]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a joint joint of a friction joint high strength bolt joint and a weld joint used for steel members of steel structures such as bridges and buildings. Only the high-strength bolt group in the row closest to the welded portion is tightened with 2/3 to 1/4 of the design tightening force, and after the welding heat is cooled, the high-strength bolt group is tightened with the design tightening force, so that the residual strength is reduced. The stress concentration can be eliminated, and a decrease in the sliding strength of the high-strength bolt can be prevented.

[0013]

According to the present invention, in a joint joint of a friction joint high strength bolt joint and a weld joint used for a steel member of a steel structure such as a bridge or a building, welding is performed after applying a high strength bolt. Concentration of residual stress due to the generated welding heat can be eliminated, and a decrease in slip strength of the high-strength bolt can be prevented.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows the present invention using a high-strength bolt joint on a web of a steel member having an H-shaped cross section and a joint joint of a friction jointed high-strength bolt joint and a welded joint using welding on a flange of the steel member having an H-shaped cross section. FIG. As shown in FIG.
The web 12 of a steel member having a cross section is sandwiched between the attached steel plates 13, and the high-strength bolt group 15a excluding the high-strength bolt group 15b in the row closest to the weld is tightened with the design tightening force. The high-strength bolt group 15b has a design tightening force of 2
After tightening by ３ to ４, the flanges 11 and 11 ′ of the H-shaped steel member are welded 14 and 14 ′, and after the welding heat is cooled, the high-strength bolt group in a row near the welded portion 15b is tightened with a design tightening force.

FIG. 2 shows a high-strength bolt formed by welding a high-strength bolt to the web and one side flange of a steel member having an H-shaped section and welding to the other flange of the steel member having the H-shaped section. It is sectional drawing of the joint joint of a joint and a welding joint. As shown in this drawing, a web 22 of a steel member having an H-shaped cross section is sandwiched between attached steel plates 23, and one flange (lower flange) 21 'of the steel member having an H-shaped cross section is further connected to attached steel plates 24, 24'. The high-strength bolt groups 26a, 26c except for the high-strength bolt group 26b in the row closest to the weld are tightened with the design tightening force, and the high-strength bolt group 26b in the row closest to the weld is tightened with the design tightening force. Welding 2/3 to 1/4, welding the other flange (lower flange) 21 of the steel member with H-shaped cross section 2
After the welding heat is cooled down, the group of high-strength bolts 26b in the row closest to the welded portion is tightened by the design tightening force.

FIG. 3 shows a joint according to the present invention, which is a combination of a high-strength bolted joint and a welded joint using a high-strength bolt for a joint rib plate of a steel pipe and welding to the steel pipe. As shown in this drawing, a steel pipe joint rib plate 31 is sandwiched between attached steel plates 32, and a high-strength bolt group 33 in the row closest to the welded portion.
After tightening the high-strength bolt group 33a excluding the b, with the design tightening force, and tightening the high-strength bolt group 33b in the row closest to the welded portion with 2/3 to 1/4 of the design tightening force, the steel pipe 3
After the welding heat of No. 4 is performed and the welding heat is cooled, the high-strength bolt group 33b in the row closest to the welded portion is tightened by the design tightening force.

Although not shown in the figure, a high-strength bolt is applied to the web of the steel member having the H-shaped cross section of the beam attached to the steel pipe at the intersection of the steel pipe and the beam, and the steel pipe is welded to the high-strength joint by welding. The present invention can also be applied to a joint joint of a bolt joint and a weld joint.

(Specific Example) In a joint joint of a friction-joined high-strength bolt joint and a welded joint having a shape as shown in FIG. 4, a state in which elastic deformation and local minute slip are mixed from an elastic deformation state. After that, the slip behavior up to the main slip condition was analyzed. In addition, as a research paper on this analysis method, "Slip Problem of Friction Welded Joint and Application to Design", Doctoral Dissertation of Tokyo Metropolitan University, published in 1991, author
Fumio Nagashima can be mentioned. As shown in this figure,
A web of an H-section steel (H588 × 300 × 12 × 20) 41 is sandwiched by an attached steel plate (PL470 × 16 × 370) 42. (a) All the high-strength bolt groups 43a and 43b are designed with a design tightening force (bolt shaft). When welding is performed in the order of the lower flange weld 44 and the upper flange weld 45 after tightening with a force of 19.6 tf) (b) The high-strength bolt group 43a except for the high-strength bolt group 43b in the row closest to the welded portion is removed. Design tightening force (bolt axial force 1
9.6tf), and tighten the high-strength bolt group 43b in the row closest to the welded portion to の of the design tightening force (bolt axial force 1).
3.1. Tf) Tightening and Flange Welding 44, 45 (c) The high-strength bolt group 43a excluding the high-strength bolt group in the row closest to the welded part is designed with the designed tightening force (bolt axial force 19.6tf). The above-mentioned analysis method is used for three cases in which the high-strength bolt group 43b in the row closest to the welded portion is tightened with １ ／ of the designed tightening force (bolt axial force 4.9 tf) and the flanges 44 and 45 are welded. Was analyzed. The analysis results of each case are shown in FIG. 5. As can be seen from FIG. 5, in case (a), the residual stress of the base metal is concentrated near the welded portion, and the value is higher than the allowable stress of steel material of 150 MPa. large. Further, the frictional force of the high-strength bolt is also concentrated on the high-strength bolt group closest to the welded portion, so that a slip occurs on the friction surface (FIG. 5 shows a state after the slip has occurred). Therefore, in the case of (a), it is necessary to replace the high-strength bolt in the row closest to the weld with a new high-strength bolt. On the other hand, (b) and (c)
In the case (1), there is no concentration of the residual stress and no concentration of the frictional force of the high-strength bolt, and it is understood that the high-strength bolt group closest to the welded portion may be tightened with the designed tightening force after the welding heat is cooled.

According to the present invention, in addition to the above-described embodiment, (1) one friction-bonded surface having one contacted steel sheet and
In the case of a surface-attached joint (2) Although not shown in the figure, when attaching a horizontal girder or bracket with another cross section to a main girder having a cross section such as H type, I type, Π type or box type (3) Further, the present invention can be applied to a case where base materials are directly connected to each other by a friction welding joint without using an impregnated steel plate.

It should be noted that the present invention is not limited to the above-described embodiment, and various modifications are possible based on the gist of the present invention, and they are not excluded from the scope of the present invention.

[0021]

As described above, according to the present invention, in a joint joint of a friction joint high strength bolt joint and a weld joint used for steel members of a steel structure such as a bridge or a building, one of the joints is provided. After applying a friction-joined high-strength bolted joint to the joint, the remaining joints are welded, and the force acting on the entire joint with the combined strength of the strength of the friction-jointed high-strength bolted joint and the strength of the welded joint In the joint with a structure that is opposed to the above, the tightening force of the high-strength bolt group closest to the welded portion among the high-strength bolts is set to 2/3 to 1/4 of the design tightening force, so that the deformation of the base material due to the heat of welding is reduced. The residual stress inside the member caused by the restraint was reduced.

[Brief description of the drawings]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing a friction-joined high-strength bolted joint and a welded joint using a welded joint on a flange of a steel member having an H-shaped section, FIG.

FIG. 2 shows a friction-joined high-strength bolted joint using a friction-joined high-strength bolt joint to a web and a lower flange of a steel member having an H-shaped section, and a welded joint to an upper flange of the steel member having an H-shaped section. It is a figure of a joint used together with a welding joint.

FIG. 3 is a view showing a joint joint of a friction-joined high-strength bolted joint and a welded joint using the present invention by friction-joining high-strength bolt joints to a joint rib plate of a steel pipe and using a welded joint to the steel pipe;

FIG. 4 shows a concrete example of the present invention, wherein a high-strength bolted joint is formed by friction welding a high-strength bolted joint to a web of a steel member having an H-shaped cross section and a welded joint is formed to a flange of the steel member having the H-shaped cross section. FIG. 4 is a view showing a shape of an analysis model of a joint used in combination with a welding joint.

FIG. 5 is an explanatory diagram showing the effect of the present invention with respect to the specific example of the present invention.

FIG. 6 is an explanatory diagram showing the elastic deformation performance of a friction-joined high-strength bolt joint, a welded joint, and a joint joint of a friction-joined high-strength bolt joint and a welded joint.

[Explanation of symbols]

11, 11 ', 21, 21' Flange of steel member having H-shaped section 12, 22 Web of steel member having H-shaped section 13, 23, 24, 24 ', 32, 42 Spliced steel plate 15a, 15b, 26a, 26b , 26c, 33a, 3
3b, 43a, 43b high-strength bolt group 14, 14 ', 2
5, 35, 44, 45 Welding 31 Steel pipe joint rib plate 34 Steel pipe 41 H-section steel

Claims (1)

(57) [Claims] 1. A combined joint having a structure in which a high strength bolt joint is applied to a part of a joint between a steel structure and a steel member and then a weld joint is applied to the remaining part of the joint. Among the high-strength bolted joints, the high-strength bolt group in the row closest to the welded joint is 部 of the design tightening force.
(2) Tighten the high-strength bolts at other locations with the design tightening force. (3) Weld the weld joint. (4) Cool the welding heat of the weld joint. And then tightening a group of high-strength bolts in the row closest to the welded joint with a designed tightening force.