Method for replacing a splice plate

Abstract

To provide a method for replacing a splice plate capable of facilitating on-site work.SOLUTION: An existing splice plate 1P is divided in a direction intersecting a butt direction of joined members 2. New splice plate segments 1N having the same shape as the divided existing splice plate 1P are sequentially replaced and the new splice plate segments 1N are joined to plate-shaped parts 2a of the joined members 2. When welding the replaced adjacent new splice plate segments 1N, grooves 5 are made in advance in weld parts of the adjacent new splice plate segments 1N.SELECTED DRAWING: Figure 11

Description

Technical Field

[0001] The present invention relates to a method for replacing a splice plate that is bridged over plate-like portions of butted joined members and joined to each plate-like portion to join the joined members together.

Background Art

[0002] Long members such as the legs and booms of an unloader, which is port cargo handling equipment, are composed of connecting a plurality of constituent members such as H-shaped steel and square pipe steel. A splice plate is used at the joint of these constituent members (joined members). The splice plate is generally applied across both sides of the plate-like portions of the butted joined members, and in that state, the joined members are joined together by joining each plate member with a fastener such as a bolt and nut. Since this splice plate is particularly likely to deteriorate in the case of port cargo handling equipment, it is necessary to replace it regularly. As a method for replacing this splice plate, for example, there are those described in Patent Document 1 and Patent Document 2 below.

[0003] Among these, the method for replacing the splice plate described in Patent Document 1 is to cut the replaceable (existing) splice plate little by little, remove the cut portion, chamfer the butting portion of the plate-like portion of the joined member that is exposed, and then weld. By repeating this sequentially in a direction orthogonal to the butting direction of the joined members, all the butting portions of the plate-like portions of the joined members are welded together and all the existing splice plates are removed. Then, a new splice plate is applied to the position where the existing splice plate was located and re-joined to the plate-like portion of the joined member.

[0004] The method for replacing a splice plate described in Patent Document 2 is to join the members to be joined that are joined by an existing splice plate with a bypass material and cut the existing splice plate into upper and lower parts. After joining the members to be joined with the bypass material, a part of the divided existing splice plate is replaced with a new splice plate of the same shape and joined to the members to be joined, and this is repeated sequentially to replace the existing splice plate with a new splice plate. After finishing replacing the existing splice plate with a new splice plate, the bypass material is removed.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in the method for replacing a splice plate described in Patent Document 1, after partially removing the existing splice plate, it is necessary to perform grooving on the plate member of the member to be joined that is exposed at the work site. Although it is easy to form a groove in a metal plate by machining, it is troublesome and time-consuming to perform grooving on the plate member at the work site. Further, in the method for replacing a splice plate described in Patent Document 2, it is necessary to prepare individual bypass materials and join and remove them to the members to be joined at the work site. Therefore, in this method for replacing a splice plate, joining and removing the bypass material requires labor and time, and using individual bypass materials also leads to an increase in cost.

[0007] The present invention has been made in view of the above problems, and an object thereof is to provide a method for replacing a splice plate that can facilitate work at the site.

Means for Solving the Problems

[0008] In order to achieve the above object, a method for replacing a splice plate according to an aspect of the present invention is as follows. In a method for replacing a splice plate that is applied across plate-like portions of butted joined members and joins the joined members by being joined to each plate-like portion, an existing splice plate is divided in a direction intersecting the butting direction of the joined members, and a new splice plate divided body having the same shape as the divided existing splice plate is sequentially replaced, and the new splice plate divided body is joined to the plate-like portion of the joined member, and adjacent replaced new splice plate divided bodies are welded to each other. The gist is that a groove is previously formed in the welded portion of the adjacent replaced new splice plate divided bodies.

Effect of the Invention

[0009] According to the present invention, the divided existing splice plate is sequentially replaced with a new splice plate divided body having the same shape, and the new splice plate divided body is joined to the joined member, and adjacent new splice plate divided bodies are welded to each other. At this time, since a groove is previously formed in the welded portion of the new splice plate divided body, the work at the site is reduced and facilitated, and the joining strength between the welded new splice plate divided bodies can be ensured.

Brief Description of the Drawings

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Embodiments for Carrying Out the Invention

[0011] Hereinafter, an embodiment of a method for replacing a splice plate of the present invention will be described in detail with reference to the drawings. The following embodiments illustrate devices and methods for embodying the technical idea of the present invention, and the technical idea of the present invention does not specify the materials, shapes, structures, arrangements, etc. of the components as in the following embodiments. Also, the drawings are schematic. Therefore, it should be noted that the relationship between the thickness and the planar dimensions, the ratio, etc. are different from the actual ones, and there are portions where the dimensional relationships and ratios are different between the drawings.

[0012] FIG. 1 is a schematic configuration diagram showing an unloader to which the method for replacing a splice plate of this embodiment is applied. For example, an unloader 50 for unloading iron ore carried by a transport ship 100 is a huge port cargo handling facility. The leg members 51 and the boom (beam member) 52 of this huge unloader 50 are particularly long, and therefore, as described above, they are configured by joining a plurality of long structural members such as H-shaped steel and square pipe steel in the longitudinal direction. The splice plate 1 is used at the joint of these structural members. FIG. 2 is a perspective view showing an example of the joint of the joined members (structural members) 2 by the splice plate 1 in the unloader 50 of FIG. 1. In this example, square pipe steels arranged to extend in the horizontal direction are joined (connected) in the longitudinal direction. The splice plate 1 is generally applied across the plate-like portions 2a of the butted joined members 2 on both sides of the plate-like portions 2a, and in that state, the joined members 2 are joined by joining each plate-like portion 2a with a fastener 3 such as a bolt and nut.

[0013] Next, as an example of the procedure for replacing (exchanging) the splice plate 1 as a result of, for example, deterioration of the splice plate 1, FIGS. 3 to 12 will be used to explain. Hereinafter, the splice plate 1 to be replaced will be referred to as the existing splice plate 1P, and the newly attached splice plate 1 will be referred to as the new splice plate. In this embodiment, since the new splice plate is in a form obtained by dividing the existing splice plate 1P, it is also referred to as the new splice plate divided body 1N. FIG. 3 is a perspective view of one of the splice plates 1 used for joining the square pipe steels in FIG. 2, specifically, the existing splice plate 1P attached to the vertical plane. First, as shown in FIG. 4, the fasteners 3 in the upper 1 / 3 range of the figure are removed, and the existing splice plate 1P is cut horizontally at the position 1 / 3 from the top of the figure and divided in the vertical direction, that is, in a direction intersecting (orthogonal) to the butting direction of the joined members 2. The order of the operations may be either first or they may be performed simultaneously. After that, as shown in FIG. 5, the upper 1 / 3 of the divided existing splice plate 1P is removed (removed).

[0014] When a part of the existing splice plate 1P is removed, as shown in FIG. 6, a new splice plate divided body 1N having the same shape as the removed divided existing splice plate 1P is applied to that part. Naturally, the new splice plate divided body 1N is provided with through holes 4 for inserting the fasteners 3. However, as will be described later, a groove 5 is provided in advance at the welding portion with the adjacent new splice plate divided body 1N. After that, the fasteners 3 are inserted through the through holes 4 of the joined member 2 and the through holes 4 of the new splice plate divided body 1N and fastened, and as shown in FIG. 7, the new splice plate divided body 1N is joined to the plate-like portion 2a of the joined member 2.

[0015] Subsequently, as shown in FIG. 7, among the remaining existing splice plates 1P, remove the fasteners 3 in the range from 1 / 3 to 2 / 3 from above the original (former) existing splice plate 1P. Also, cut the remaining existing splice plate 1P at the position of 2 / 3 from above the original existing splice plate 1P and divide it vertically, that is, in a direction intersecting (orthogonal) to the butting direction of the members to be joined 2. The order of the operations may be either first or they may be carried out simultaneously. That is, the existing splice plate 1P divided in this step corresponds to 1 / 3 of the whole in the range from 1 / 3 to 2 / 3 from above the original existing splice plate 1P. After that, as shown in FIG. 8, remove (eliminate) the existing splice plate 1P in the divided range from 1 / 3 to 2 / 3.

[0016] When a part of the existing splice plate 1P is removed, as shown in FIG. 9, apply a new splice plate divided body 1N having the same shape as the removed divided existing splice plate 1P to that part. In this new splice plate divided body 1N, similarly to the above, through holes 4 for inserting the fasteners 3 are provided, and grooves 5 are pre-formed at the welding parts with adjacent new splice plate divided bodies 1N. After that, insert the fasteners 3 through the through holes 4 of the members to be joined 2 and the through holes 4 of the applied new splice plate divided body 1N and fasten them, and as shown in FIG. 10, join the new splice plate divided body 1N in the range from 1 / 3 to 2 / 3 from above to the plate-like part 2a of the members to be joined 2.

[0017] Next, as shown in FIG. 10, after removing the fastener 3 of the remaining existing splice plate 1P, remove (remove) the remaining existing splice plate 1P. This corresponds to the range of 1 / 3 from below the original existing splice plate 1P. When the remaining existing splice plate 1P is removed, as shown in FIG. 11, a new splice plate segment 1N having the same shape as the removed divided existing splice plate 1P is applied to that portion. Similarly to the above, the new splice plate segment 1N is also provided with a through hole 4 for inserting the fastener 3, and a groove 5 is provided in advance at the welding portion with the adjacent new splice plate segment 1N. After that, insert the fastener 3 through the through hole 4 of the joined member 2 and the through hole 4 of the applied new splice plate segment 1N and fasten them. As shown in FIG. 12, join the new splice plate segment 1N in the range of 1 / 3 from below to the plate-like portion 2a of the joined member 2.

[0018] When the existing splice plate 1P is replaced with three new splice plate segments 1N in this way, as shown in FIG. 12, weld the abutting (butting) portions of the adjacent new splice plate segments 1N to each other. The welding is performed at the grooves 5 facing each other, so that sufficient welding strength can be obtained. When the three new splice plate segments 1N are integrated by this welding, the replacement work of the splice plate itself is completed. Note that when welding the new splice plate segment 1N, the new splice plate segment 1N may thermally expand, and as a result, the tightened bolt may elongate and the bolt axial force may decrease. In such a case, after the welding of the new splice plate segment 1N is completed, the required bolt axial force can be ensured by replacing all the bolts used. Also, when using high-strength bolts for the bolts and replacing the high-strength bolts, replace the bolts one row at a time. The order of replacement at this time is based on the tightening order of the high-strength bolt tightening in the welding joint design and construction guidebook.

[0019] Next, a method for setting the number of divisions of the existing splice plate 1P, that is, the number of new splice plate divided bodies 1N, will be described. First, assume that the joined member 2 is a single flat steel (= plate-shaped portion 2a), and a case where a tensile force acts in the direction of the arrow in FIG. 2, that is, in the longitudinal direction of the joined member (structural member) 2, will be described. FIG. 13 is a cross-sectional view of a portion where the joined member 2 made of flat steel is joined by two existing splice plates 1P. Further, FIG. 14 is a cross-sectional view of a portion other than the joined portion of the joined member 2 made of flat steel, that is, the joined member 2 itself. Through holes 4 for inserting the fasteners 3 are not formed in the joined member 2 at portions other than the joined portion. Let the cross-sectional area of this joined member 2 itself be Am 2 be denoted as such. FIG. 15 is a cross-sectional view of a portion where the through holes 4 are formed in the two existing splice plates 1P. Let the cross-sectional area of the two existing splice plates 1P at the portion where the through holes 4 are formed be Bm 2 be denoted as such. Note that the thickness of the new splice plate divided body 1N is made equal to the thickness of the existing splice plate 1P, and here, the cross-sectional area of the groove 5 formed in the new splice plate divided body 1N is ignored.

[0020] As shown in FIG. 16, first, let the cross-sectional area of the existing splice plate 1P to be divided first be Cm 2 be denoted as such. Then, the cross-sectional area of the remaining existing splice plates 1P is (B - C)m 2 becomes. The cross-sectional area (B - C)m 2 of the remaining existing splice plates 1P is greater than or equal to the cross-sectional area Am 2 of the joined member 2 itself. The cross-sectional area Cm 2 of the divided existing splice plate 1P is obtained. As shown in FIG. 17, let the cross-sectional areas of each of the existing splice plates 1P finally divided be D1m 2 , D2m 2 , D3m 2 be denoted as such. Then, each satisfies D1m 2 ≤ Cm 2 , D2m 2 ≤ Cm 2 , D3m 2 ≤ Cm 2 . The cross-sectional areas D1m 2 , D2m2 and D3m 2 may or may not be equal to each other. Also, when the dimension in the direction perpendicular to the plane of the drawing, i.e., the dimension in the butting direction of the members to be joined 2, is constant, the cross-sectional areas D1m 2 and D2m 2 and D3m 2 of the existing splice plate 1P of the final split are determined by the dimension in the vertical direction of the drawing. At this time, the position of each split line is set so that the split line of the existing splice plate 1P of the final split does not interfere with the fastener 3 (or its through-hole 4), and accordingly, the cross-sectional areas D1m 2 and D2m 2 and D3m 2 of the existing splice plate 1P of the final split are set. By setting the cross-sectional areas D1m 2 and D2m 2 and D3m 2 of the existing splice plate 1P of the final split in this way, the number of splits of the existing splice plate 1P is set.

[0021] Next, a method for setting the number of splits of the existing splice plate 1P, i.e., the number of new splice plate split bodies 1N, when the member to be joined 2 is a square pipe steel will be described. Also in this case, it is assumed that a tensile force acts in the direction of the arrow in FIG. 2, i.e., in the longitudinal direction of the member to be joined (structural member) 2. FIG. 18 is a cross-sectional view of a portion where the member to be joined 2 made of square pipe steel is joined by a total of 8 existing splice plates 1P. FIG. 19 is a cross-sectional view of a portion other than the joint portion of the member to be joined 2 made of square pipe steel, i.e., the cross-section of the member to be joined 2 itself. No through-hole 4 for inserting the fastener 3 is formed in the member to be joined 2 in the portion other than the joint portion. Let the cross-sectional area of this member to be joined 2 itself be Em 2 . FIG. 20 is a cross-sectional view of a portion where the through-holes 4 of a total of 8 existing splice plates 1P are formed. Let the cross-sectional area of the total 8 existing splice plates 1P in the portion where the through-holes 4 are formed be Fm 2 . Note that the thickness of the new splice plate split body 1N is the same as the thickness of the existing splice plate 1P, and here too, the cross-sectional area of the groove 5 formed in the new splice plate split body 1N is ignored.

[0022] As shown in Fig. 21, let the cross-sectional area of the existing splice plate 1P to be first divided be Gm 2 Then, the cross-sectional area of the remaining existing splice plate 1P is (F - G)m 2 The cross-sectional area (F - G)m of this remaining existing splice plate 1P 2 is equal to or greater than the cross-sectional area Em of the joined member 2 itself 2 Find the cross-sectional area Gm of the divided existing splice plate 1P 2 As shown in Fig. 22, let the cross-sectional areas of each existing splice plate 1P to be finally divided be H1m 2 , H2m 2 , H3m 2 , H4m 2 , H5m 2 Then, they satisfy H1m 2 ≤ Gm 2 , H2m 2 ≤ Gm 2 , H3m 2 ≤ Gm 2 , H4m 2 ≤ Gm 2 , H5m 2 ≤ Gm 2 The cross-sectional areas H1m 2 ~H5m 2 of the finally divided existing splice plate 1P may be equal to each other or may not be equal. Also, when the dimension in the direction perpendicular to the paper surface of the figure, that is, the dimension in the butting direction of the joined member 2, is constant, the cross-sectional areas H1m 2 ~H5m 2 of the finally divided existing splice plate 1P are determined by the vertical and horizontal dimensions of the figure. At this time, set the position of each dividing line so that the dividing line of the finally divided existing splice plate 1P does not interfere with the fastener 3 (or its through-hole 4), and accordingly set the cross-sectional areas H1m 2 ~H5m 2 of the finally divided existing splice plate 1P. By setting the cross-sectional areas H1m 2 ~H5m 2 of the finally divided existing splice plate 1P in this way, the number of divisions of the existing splice plate 1P is set.

[0023] The joined member is stable against tensile force (the stress is less than the breaking strength) due to the cross-sectional area of the joined member 2 itself without holes. This is applied to the joint of the joined member 2 by the existing splice plate 1P, and the remaining cross-sectional area of the existing splice plate 1P that has been divided and partially removed is made equal to or greater than the cross-sectional area of the joined member 2 itself. As a result, at the joint of the joined member 2, the joined members 2 are joined by the existing splice plate 1P with a cross-sectional area equal to or greater than that of the joined member 2 itself, and the strength against tensile force can be ensured. For example, at the joint of the joined member 2 made of square pipe steel in Fig. 18, it is easier to ensure strength by adopting the splitting method shown in Figs. 15 to 17 for the plate-like part 2a that constitutes one side of the square cross-section. Therefore, in this embodiment, the number of divisions of each of the two existing splice plates 1P sandwiching one plate-like part 2a is set to 3, the existing splice plate 1P is evenly divided into 3 parts, and a new splice plate divided body 1N with a corresponding shape is created and used. In addition, for the cross-section where a bending moment acts on the existing splice plate 1P, the number of divisions may be set by comparing the section moduli instead of the cross-sectional areas.

[0024] In this way, in the method for replacing the splice plate according to the embodiment, the divided existing splice plate 1P is sequentially replaced with a new splice plate divided body 1N of the same shape and joined to the joined member 2, and the adjacent new splice plate divided bodies 1N are welded together. At this time, since the groove 5 is provided in advance at the welded part of the new splice plate, the work at the site is reduced and facilitated, and the joining strength of the welded new splice plates can be ensured.

[0025] Also, based on the cross-section of the joined member 2 itself and the cross-section of the splice plate 1, the number of divisions of the existing splice plate 1P is set so that predetermined cross-sectional characteristics can be ensured in the state where the divided existing splice plate 1P is removed. Thereby, the strength of the joint of the connected member against tensile force and bending moment during splice plate replacement can be ensured. In addition, when it is compressive force instead of tensile force, it is necessary to consider buckling.

[0026] Also, the number of divisions of the existing splice plate 1P is set based on the cross-sectional area of the existing splice plate 1P in a state where the divided existing splice plate 1P is removed, and the cross-sectional area of the splice plate 1 is equal to or greater than the cross-sectional area of the member 2 to be joined itself. Thereby, the strength of the joint portion of the member to be connected with respect to the tensile force during the replacement of the splice plate can be ensured.

[0027] As described above, the method for replacing the splice plate according to the embodiment has been described. However, the present invention is not limited to the configuration described in the above embodiment, and various modifications are possible within the scope of the gist of the present invention. For example, in the above embodiment, only the joint portion where the member 2 to be joined made of square pipe steel is joined with the splice plate 1 has been described, but it can be similarly applied to the joint portions of various members 2 to be joined such as H-shaped steel and angle steel.

[0028] Also, in the above embodiment, only the joint portion where the constituent members constituting the member of the unloader 50 are used as the member 2 to be joined has been described. However, the applicable location of the joint portion is not limited to this, and it can be applied to the joint portions of various facilities joined with the splice plate 1.

Explanation of Reference Numerals

[0029] 1 Splice plate 1P Existing splice plate 1N New splice plate divided body 2 Member to be joined 2a Plate-like portion 3 Fastener 4 Through hole 5 Groove

Claims

Claim 1 In a method for replacing a splice plate that is applied across plate-like portions of butted joined members and joins the joined members by being joined to each plate-like portion, an existing splice plate is divided in a direction intersecting the butting direction of the joined members, and a new splice plate divided body having the same shape as the divided existing splice plate is sequentially replaced, and the new splice plate divided body is joined to the plate-like portion of the joined members, adjacent replaced new splice plate divided bodies are welded together, and a groove is pre-formed in the welded portion of the adjacent replaced new splice plate divided bodies. A method for replacing a splice plate. Claim 2 The number of divisions of the existing splice plate is set based on the cross-section of the joined member itself and the cross-section of the splice plate so that predetermined cross-sectional characteristics can be ensured in a state where the divided existing splice plate is removed. The method for replacing a splice plate according to claim 1. Claim 3 The number of divisions of the existing splice plate is set based on the cross-sectional area of the divided existing splice plate such that the cross-sectional area of the splice plate in a state where the divided existing splice plate is removed is equal to or greater than the cross-sectional area of the joined member itself. The method for replacing a splice plate according to claim 2.

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