JP7189405B2 - Welding methods and fulcrum reinforcement methods for truss bridges - Google Patents

Description

The present invention relates to a welding technique, particularly a connection method suitable for completely penetration welding of another plate member to a part of plate members stacked in the plate thickness direction, and a fulcrum reinforcement method applying this method to a truss bridge. Regarding.

Butt welding, fillet welding, partial penetration welding, and the like are known as welding techniques for building structures. Among these techniques, when performing butt welding, it is common to form a groove in the base material and provide a root gap to perform full penetration welding. When performing such full penetration welding, it has been common to arrange a backing metal on the side opposite to the groove formation surface and perform welding together with this backing metal.

However, there is concern that such a method may exert concentrated stress on the welded portion of the backing metal, which may adversely affect the seismic resistance of the building. On the other hand, Patent Literature 1 discloses that full penetration welding is performed so that the front and back surfaces of the base material are built up so as not to produce steps or corners at the welded location.

JP 2015-77618 A

By performing butt welding by the method disclosed in Patent Document 1, stress concentration can be alleviated, and it is thought that strength anxiety can be eliminated.

However, the welding method disclosed in Patent Literature 1 is a technique for butt welding of single plates. For this reason, when butt-welding another plate member to a part of the laminated plate members, it is conceivable that a stress concentration point may occur due to melting of the adjacent members. In addition, the technique disclosed in Patent Document 1 also has a problem that it cannot be applied unless it is possible to weld from the front and back.

Therefore, in the present invention, a welding method that enables butt welding by full penetration welding to a part of a laminated plate and allows construction from one side, and a fulcrum reinforcement method that applies such a welding method to a truss bridge. intended to provide

A welding method according to the present invention for achieving the above object is a method of performing full penetration welding of a base material to be welded, which is one of laminated members composed of a plurality of plate materials , to a base material to be welded, the method comprising: A groove is formed on the butt side end face of the welding base material from one main surface side, and a main contact of the plate material adjacent to the plate material constituting the base material to be welded among the laminated members is in contact with the base material to be welded. After chamfering the corner between the surface and the end face on the side where the butt side end face of the base metal to be welded is located, and providing a root interval between the base metal to be welded and the base metal to be welded A backing material is brought into contact with the other main surface side of the base material to be welded at a position provided with the root spacing, and is welded between the butt side end surface of the base material to be welded and the groove forming part of the base material to be welded. It is characterized by melting and joining metal.

Further, in the welding method having the characteristics described above, the backing material is removed after the welding is completed. With such features, there is no risk of stress concentration occurring at the contact portion of the backing material.

Further, in the welding method having the above characteristics, the base material to be welded has the plate material adjacent to both one main surface side and the other main surface side, and the backing material has an end portion can be provided with an inclined surface on the side of the plate material, and the inclined surface can be fitted into the chamfered portion of the plate adjacent to the other main surface side . With such characteristics, any member existing in any part of the laminated member can be used as a base material to be welded. Further, by pressing the end of the backing material against the chamfered portion, it is possible to prevent the backing material from slipping during welding.

Further, in the truss bridge fulcrum reinforcement method for achieving the above object, when a temporary support is arranged near the fulcrum constituting the truss bridge and the lower chord member is lifted, part of the web that constitutes the diagonal member And, when joining a part of the webbing that constitutes the lower chord member with the first stiffening member, the webbing of the diagonal member is used as the base material to be welded, and the first stiffening member is used as the base material for welding, and the welding is performed It is characterized by applying a method.

Furthermore, in the truss bridge fulcrum reinforcing method having the above characteristics, the second stiffener is joined between the web of the diagonal member and the vertical member, and after the joint state is inspected, the second stiffener is joined. 2 It is good to set it as the structure which cuts off a part of stiffener. By adopting such a method, it is possible to perform an ultrasonic inspection of the welded portion even if the plate width is narrow in design, and the quality can be improved.

According to the welding method having the characteristics described above, it is possible to perform butt welding by full penetration welding on a part of the laminated plate. In addition, construction from one side can be made possible.

In addition, by applying this welding method to the fulcrum reinforcement method of a truss bridge, the stiffener can completely penetrate into the central plate of the laminated plate without affecting the adjacent plate. can be welded.

It is a figure which shows the cross-section of the welding structure which concerns on embodiment. It is a perspective view which shows the base material applied to the welding structure which concerns on embodiment. FIG. 5 is a diagram for use in explaining a method for obtaining a welded structure according to an embodiment; It is a front view which shows the structure of the support part of the bridge which applies the welding structure which concerns on embodiment. FIG. 5 is a view showing a part of the AA cross section in FIG. 4; FIG. 4 is a partial cross-sectional view for explaining a method of joining stiffeners and lower chord members; FIG. 10 is a front view showing the form of stiffener welding at the bearing portion of the bridge. It is a sectional view showing the 1st application form in welding structure concerning an embodiment. It is a sectional view showing the 2nd application form in welding structure concerning an embodiment.

EMBODIMENT OF THE INVENTION Hereinafter, the welding method of this invention and embodiment which concerns on a welding structure are described in detail with reference to drawings. In addition, the form shown below is a part of suitable form in order to implement this invention. Therefore, as long as the effect is exhibited, even if a part of the configuration is changed, it can be regarded as a part of the present invention.

[Basic form]
First, with reference to FIGS. 1 to 3, the features of the welded structure according to this embodiment will be described. 1 is a diagram showing a cross-sectional structure of the welded structure according to the embodiment, and FIG. 2 is a perspective view showing a base material applied to the welded structure according to the embodiment. Moreover, FIG. 3 is a figure used for demonstrating the method for obtaining the welded structure which concerns on embodiment.

In the welded structure 10 according to the present embodiment, one of the plate materials 12a to 12c constituting the laminated member 12 is used as a base material to be welded, and a welding base material 14, which is a plate material, is welded to the base material to be welded. It is. In the embodiment shown in FIG. 1, the central plate member 12b of the laminated member 12 composed of three plate members 12a to 12c is used as the base material to be welded.

The welding base material 14 is formed with a groove 16 on the end face on the butt side. The angle and depth of the groove 16 can be determined according to the thickness of the weld base material 14, the degree of penetration of the weld metal 18, workability, and the like. In this embodiment, the plate thickness is 16 mm, and full penetration welding is performed, so the depth of the groove extends from one main surface to the other main surface of the plate material forming the weld base material 14 . Further, the angle of the groove 16 (bevel angle θ) is approximately 35 degrees.

The laminated member 12 to which the welding base material 14 is welded has chamfers 20 on the end faces of plate members 12a and 12c arranged adjacent to the base material to be welded (plate member 12b). The chamfers 20 are applied to the corners between the main surfaces of the plate materials 12a and 12c that contact the base material to be welded (plate material 12b) and the butting side end surfaces of the base material to be welded (plate material 12b). The size of the chamfer 20 varies depending on the thickness of the plate members 12a and 12c, the welding range, and the like.

As described above, in the welded structure 10 according to the present embodiment, by forming the groove 16 only on the welding base material 14 side, butt welding with the groove 16 of the L-type or J-type is performed. . A root gap d is provided between the base material to be welded (the plate material 12b) and the base material 14 to be welded. In this embodiment, the root interval d is approximately 5 mm.

In this embodiment, the deposited metal 18 is raised on one main surface of the weld base material 14 where the opening of the groove 16 is large. On the other hand, on the other main surface side of the weld base material 14, the weld metal 18 exposed from the root interval d is configured to be flat.

[Welding method]
A welding method for obtaining such a welded structure 10 will be described with reference to FIG. First, as shown in FIG. 3A, a laminated member 12 including a base material 14 to be welded and a base material to be welded (plate material 12b) to be welded is prepared.

Next, as shown in FIG. 3(B), a groove 16 is formed on the butt-side end surface of the weld base material 14 . Along with the formation of the groove 16 on the welding base material 14, or before or after, the plate materials 12a and 12c adjacent to the base material to be welded (plate material 12b) in the laminated member 12 are chamfered 20. As shown in FIG. Here, the forming angle θ of the groove 16 and the width of the chamfer 20 are appropriately determined.

After forming the groove 16 on the welding base material 14 and chamfering 20 on both the laminated member 12, as shown in FIG. , and the backing material 22 is brought into contact with the other main surface side of the weld base material 14 . Here, it is preferable that the backing material 22 is made of a material that does not adhere by welding. Specifically, the backing material 22 made of ceramics may be used. By using such a backing material 22, the backing material 22 can be removed after welding is completed. Therefore, there is no risk of stress concentration occurring at the contact portion of the backing material 22 . Also, the backing material 22 is preferably provided with an inclined surface 22a at its end so that it fits into the chamfered portion 20 formed on the plate material 12c. This is because pressing the end of the backing material 22 against the chamfered portion 20 can prevent the backing material 22 from slipping during welding.

Next, as shown in FIG. 3(D), welding is performed with the deposited metal 18 while the backing material 22 is in contact with the other main surface of the base material 14 to be welded. Since the backing material 22 is arranged on the other main surface side of the weld base material 14, the deposited metal 18 forms a bulge only on one main surface side. After welding is complete, the welded structure 10 is completed by removing the backing material 22 .

By performing welding by such a method, butt welding by full penetration welding to a part of the laminated member 12 becomes possible. In addition, since a part of the plate members 12a and 12c arranged adjacent to the base material to be welded (the plate member 12b) is not welded, it is possible to avoid concentration of stress on an unexpected welded portion. In addition, according to the welding method as described above, it is possible to work from one main surface of the weld base material 14, and it is possible to cope with the case where it is difficult to work from the other main surface side.

[Case Study]
The welding method as described above can be applied to, for example, welding of a stiffener (first stiffener) 40 to a bearing portion 30 in a bridge (for example, a truss bridge) as shown in FIG.

For example, the support portion 30 shown in FIG. 4 is a portion forming a grid point where a vertical member 36 and a diagonal member 38 converge on a lower chord member 34 supported by a support 32 . When replacing the bearing 32 of the bearing portion 30 having such a structure, a temporary support portion (jack) is arranged at the position indicated by the two-dot chain line in FIG. It will be lifted. For this reason, stiffeners 40 are welded at positions hatched with oblique lines between the webs forming the diagonal members 38 and the webs forming the lower chord members 34, and the diagonal members 38 and the vertical members 36 are welded. A stiffener (second stiffener) 46 is welded therebetween. Here, the portion P enclosed by the broken line comprises the diagonal member 38 configured to have an H-shaped structure, the filler plate 42 arranged outside the diagonal member 38, and the exterior according to the basic configuration described above. The splicing plate 44 has a three-layer structure (each of which constitutes a web that receives a shear force on the diagonal member 38).

In this application example, when the stiffening member 40 is welded to the portion surrounded by the dashed line P, as shown in the AA cross section in FIG. 4 in FIG. Welding is performed to the filler plate 42 . As for the welding method, it is sufficient to follow the basic form described above. That is, on the support portion 30 side, the butting side end faces of the diagonal member 38 and splice plate 44 that are arranged adjacent to the filler plate 42 and constitute the laminated member are chamfered. On the other hand, on the stiffener 40 side, a groove 40a is formed on the butting side end face. The bevel 40a is formed so that an inclined surface appears on the outer surface of the stiffener 40. As shown in FIG.

After completing the formation of the chamfers 38a and 44a and the groove 40a, a root spacing d is provided between the filler plate 42 and the stiffener 40, and backing is provided at the root spacing d from the inner side of the stiffener 40. Welding is performed by applying the material 22 (see FIG. 3). Welding is performed from the outer surface side of the stiffener 40 . By welding only from the outer surface, the stiffener 40 can be welded even if welding from the inner surface (the other main surface) is difficult. In addition, since the chamfers 38a and 44a are applied to the portions adjacent to the butting side end surfaces, there is no possibility that the diagonal members 38 and splice plates 44 laminated on the filler plate 42 will be welded. As a result, it is possible to suppress the stress from being concentrated on the welded portion and the occurrence of cracks or the like.

Next, welding of the stiffening member 40 and the lower chord member 34 shown in FIG. 4 will be described. As shown in a part of the cross section of FIG. 6, the lower chord member 34 forms a box structure by joining the edge surfaces of the horizontal member 34a and the vertical member 34b through the weld metal 48 by fillet welding. (See FIG. 6(A)). In this embodiment, in order to join the stiffener 40 and the vertical member 34b, the deposited metal 48 due to fillet welding is completely removed as shown in FIG. 6(B). After removing the welded metal 48, the backing material 50 is installed between the back side (inner side) of the stiffener 40 and the horizontal member 34a. Then, with the backing material 50 arranged, complete penetration welding is performed between the stiffening material 40 and the vertical member 34b from the outside (surface side) of the stiffening material 40, and as shown in FIG. A weld metal 52 is used for bonding.

Subsequently, when joining stiffeners 46 as shown in FIG. 4, as shown in FIG. The part shown) is removed. For bridge welds, ultrasonic inspections are performed to determine whether full penetration welds have been achieved. At this time, a predetermined distance is required from the ultrasonic generator to the welded portion (the rated value is determined by the inspection device). For this reason, when welding, the plate material 46a having a plate width greater than the minimum required distance for inspection is joined, and after finishing the inspection of the welded part, unnecessary design parts are deleted to reduce the stress generated in the corners. Concentration can be avoided.

Similarly, the fillet portion of the stiffening member 40 (the hatched end portion of the stiffening member 40 in FIG. 7) is also similarly subjected to ultrasonic inspection between the lower chord member 34, which is the weld site. requires a distance equal to or greater than the minimum required distance. For this reason, it is preferable to similarly inspect the fillet portion in a state of having a sufficient plate width, and then cut off the unnecessary portion.

In the above embodiment, regarding the welding of the weld base material 14 to the laminated member 12, it has been described that the central plate material 12b among the three laminated plate materials 12a to 12c is welded as the base material to be welded. However, as shown in FIGS. 8 and 9, the welding method and the welded structure according to the present invention can be carried out regardless of which position of the laminated member 12 the plate materials 12a to 12c are used as the base material to be welded. can be done.

For example, as shown in FIG. 8, when the plate material 12a laminated on the top among the three plate materials 12a to 12c is used as the base material to be welded, the plate material 12b arranged adjacent to this plate material 12a In other words, the chamfering 20 should be applied only to the central plate member 12b. Further, as shown in FIG. 9, even when the plate member 12c, which is the bottom layer among the three plate members 12a to 12c, is used as the base material to be welded, only the plate member 12b arranged in the center is used. Chamfering 20 may be applied.

In either form, the base material to be welded and the base material to be welded 14 can be joined by welding only from one main surface side of the base material 14 to be welded, as in the above-described embodiment. .

10 Welded structure 12 Laminated member 12a to 12c Plate material 14 Weld base material 16 Groove 18 Weld metal 20 Chamfer 22 …… Backing member 22a …… Inclined surface 30 …… Bearing part 32 …… Bearing 34 …… Lower chord member 34a …… Horizontal member 34b …… Vertical member 36 …… Vertical member 38 …… Diagonal member 38a …… Chamfer 40 …… Stiffening member 40a …… Groove 42 …… Filler plate 44 …… Splicing plate 44a …… Chamfer, 46 …… Stiffener, 46 a …… Plate, 48 …… Weld metal, 50 …… Backing material, 52 …… Weld metal.

Claims (5)

Consists of multiple plates laminated memberone plank ofas the base metal to be weldedis a plateA method for full penetration welding of a base material to be welded, comprising:
On the butt side end face of the welding base metalfrom one main sideforming a groove,
The base material to be welded of the laminated memberplate materials that make upadjacent toin boardThe base material to be weldedbetween the main surface in contact with and the end face on the side where the butt side end face of the base metalChamfered corners,
After providing a root interval between the base metal to be welded and the base metal to be welded, the other of the base metals to be welded ismainThe backing material is brought into contact with the position where the root interval is provided from the surface side,
A welding method, wherein welding metal is melted between the butt-side end face of the base material to be welded and a groove forming portion of the base material to be welded. The method of claim 1, wherein said backing material is removed after welding is completed. The base material to be welded has the plate material adjacent to both one main surface side and the other main surface side,
3. The backing material has an inclined surface at its end, and the inclined surface is fitted to the chamfered portion of the plate adjacent to the other main surface. Welding method described in. When the lower chord members are lifted by arranging the temporary supports near the fulcrum that constitutes the truss bridge, a part of the webs that make up the diagonal members and a part of the webs that make up the lower chord members are used as the first reinforcement. A truss bridge characterized by applying the welding method according to any one of claims 1 to 3 when joining rigid members, with the web of the diagonal member being the base material to be welded and the first stiffening member being the base material to be welded. fulcrum reinforcement method. joining a second stiffener between the web of the diagonal member and the vertical member;
5. The fulcrum reinforcement method for a truss bridge according to claim 4 , wherein a part of said second stiffener is cut off after finishing the joint state inspection.

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