JP6127861B2 - Steel pipe sheet pile manufacturing method and steel pipe sheet pile - Google Patents

Description

  The present invention relates to a manufacturing method of a steel pipe sheet pile including a steel pipe sheet pile main pipe and a joint steel pipe, and a steel pipe sheet pile manufactured by the manufacturing method.

  A steel pipe sheet pile is comprised from the steel pipe sheet pile main pipe (henceforth only a "main pipe") used as a base material, and various joint materials provided along the axial direction on the outer surface of the main pipe. As a joint of a steel pipe sheet pile, joints, such as PP joint (pipe-pipe joint) and PT joint (pipe-T type steel joint), are used, for example. In these PP joints and PT joints, joint steel pipes that are pipes are used as the joint materials. And a main pipe and a joint steel pipe are welded, and a steel pipe sheet pile is manufactured. As described above, various methods have been proposed as a method for welding the main pipe and the joint steel pipe.

  For example, in order to weld a main pipe and a joint steel pipe with high efficiency, as shown in FIG. 8, a method of welding a steel pipe sheet pile 100 with a stabilizer bar 110 interposed between the main pipe 101 and the joint steel pipe 102 has been proposed. (Patent Document 1). The stability bar 110 has a single plate shape, and both surfaces thereof are curved along the outer surface of the main pipe 101 and the outer surface of the joint steel pipe 102, respectively.

  Further, in Patent Document 1, as a conventional technique, in a welded portion 120 where a main pipe 101 and a joint steel pipe 102 are welded as shown in FIG. It is described that a round steel (filling rod) 121 is provided. In such a case, after temporarily welding the main pipe 101 and the joint steel pipe 102, the round steel 121 is pushed into the welded portion 120, and the main pipe 101 and the joint steel pipe 102 are finally welded in this state.

  Further, as shown in FIG. 10, in order to secure the bead width of the welded portion 120, after temporarily welding the main pipe 101 and the joint steel pipe 102, iron powder 130 (or steel grains) is supplied to the welded portion 120. It has also been proposed to perform main welding of the main pipe 101 and the joint steel pipe 102 in a state (Patent Document 2).

Japanese Patent Publication No.2-223269 JP 2011-101892 A

  However, when the stabilizer bar 110 is used as described in Patent Document 1, the distance between the main pipe 101 and the joint steel pipe 102 is increased by the provision of the stabilizer bar 110. Then, for example, as shown in FIG. 11, when the steel pipe sheet pile 100 has a PP joint, the sheet pile width L of the steel pipe sheet pile 100, that is, the distance L between the joint steel pipes 102, 102 provided on both sides of the main pipe 101 is There may be an upper limit within specification tolerances. If it does so, when steel pipe sheet pile 100 is connected, there is a possibility that it may not be connected without becoming a predetermined size.

  Furthermore, when the stabilizer bar 110 is used, welding becomes difficult and undercut increases. Further, the forming process of the stability bar 110 is complicated, and the manufacturing cost of the steel pipe sheet pile 100 is increased because the stability bar 110 is large.

  Moreover, when the round steel 121 is used as described in Patent Document 1, when the main pipe 101 and the joint steel pipe 102 are main-welded, an operation of pushing the round steel 121 into the welded portion 120 occurs. Here, it is known that the throughput for manufacturing the steel pipe sheet pile 100 is limited to the main welding of the main pipe 101 and the joint steel pipe 102. Then, by using the round steel 121, it takes time for the main welding of the main pipe 101 and the joint steel pipe 102, and there is room for improvement in the manufacturing throughput of the steel pipe sheet pile 100.

  Further, when the round steel 121 is used and the diameter of the round steel 121 is small, for example, less than 10 mm, the meltdown at which the weld metal melts increases. On the other hand, when the diameter of the round steel 121 is large, for example, 10 mm or more, there is a concern that the tip of the round steel 121 gets stuck in the welded portion 120 and a defect occurs. Moreover, when the diameter of the round steel 121 is large, the manufacturing cost of the steel pipe sheet pile 100 will increase accordingly.

  In addition, when iron powder 130 is used as described in Patent Document 2, when main welding of the main pipe 101 and the joint steel pipe 102 is performed, an operation of supplying the iron powder 130 to the welded portion 120 occurs. The main welding takes time, and there is room for improvement in the manufacturing throughput of the steel pipe sheet pile 100.

  Moreover, when the iron powder 130 is used, since the iron powder 130 is easy to melt, meltdown becomes large.

  As described above, when the conventional manufacturing method is used, there is room for improvement in the quality of the steel pipe sheet pile 100, and there is room for improvement in the manufacturing throughput and manufacturing cost of the steel pipe sheet pile 100.

  This invention is made | formed in view of this point, and it aims at improving the manufacture efficiency of a steel pipe sheet pile while improving the quality of a steel pipe sheet pile.

  In order to achieve the above object, the present invention is a method for manufacturing a steel pipe sheet pile comprising a steel pipe sheet pile main pipe and a joint steel pipe provided along the axial direction on the outer surface of the steel pipe sheet pile main pipe, the joint steel pipe A first step of providing a pair of connecting members extending in the axial direction and having a rectangular cross section on the outer surface of the joint steel pipe along the axial direction and on both sides of the center line of the joint steel pipe; Then, it has a 2nd process of welding a pair of said connection member and the said joint steel pipe to the outer surface of the said steel pipe sheet pile main pipe, It is characterized by the above-mentioned.

  As a result of intensive studies by the inventors, when a connecting member having a rectangular cross section as in the present invention is used as a connecting member provided in a welded portion where a steel pipe sheet pile main pipe and a joint steel pipe are welded, the steel pipe sheet pile main pipe is used. It was found that the joint steel pipe can be welded properly. Specifically, since the connecting member is provided in the welded portion, the width of the bead required in the welded portion can be ensured. Moreover, since the cross section of a connection member has rectangular shape, an undercut and a meltdown can be suppressed. In addition, the effect which can suppress undercut and a meltdown in this way is demonstrated in detail also in the below-mentioned Example. As described above, according to the present invention, the quality of the steel pipe sheet pile can be improved.

  Moreover, according to this invention, before welding a steel pipe sheet pile main pipe and a joint steel pipe (main welding), the connection member is previously attached to the joint steel pipe. For this reason, the time which this welding takes can be shortened and the manufacturing throughput of a steel pipe sheet pile can be improved.

  Further, according to the present invention, since the cross section of the connecting member has a rectangular simple structure, the connecting member can be easily designed and easily manufactured. Therefore, the manufacturing cost of the steel pipe sheet pile can be reduced.

  The first step and the second step may be performed in different production lines.

  The cross-section of the connecting member preferably has a rectangular shape with a side length of 10 mm to 19 mm and a side length of 2 mm to 5 mm.

  The present invention according to another aspect is a steel pipe sheet pile including a steel pipe sheet pile main pipe and a joint steel pipe provided by welding along the axial direction on the outer surface of the steel pipe sheet pile main pipe, Between the joint steel pipe, a pair of welds for welding the steel pipe sheet pile main pipe and the joint steel pipe is formed across a center line connecting the center of the steel pipe sheet pile main pipe and the center of the joint steel pipe, The welded portion is provided with a connecting member that extends along the axial direction of the joint steel pipe and has a rectangular cross section.

  The cross-section of the connecting member preferably has a rectangular shape with a side length of 10 mm to 19 mm and a side length of 2 mm to 5 mm.

  ADVANTAGE OF THE INVENTION According to this invention, while improving the quality of a steel pipe sheet pile, the manufacturing efficiency of a steel pipe sheet pile can be improved.

It is a top view which shows the outline of a structure of the steel pipe sheet pile manufacturing equipment which manufactures the steel pipe sheet pile concerning this Embodiment. It is explanatory drawing which shows a mode that a connection member is attached to a joint steel pipe. It is explanatory drawing which shows a mode that a connection member is attached to a joint steel pipe. It is a side view which shows the detail of the welding part vicinity at the time of temporarily attaching a joint steel pipe to a main pipe. It is explanatory drawing which shows a mode that a joint steel pipe is main-welded to a main pipe. It is a side view which shows the detail of the welding part vicinity at the time of carrying out the main welding of the joint steel pipe to a main pipe. In a comparative example, it is a side view which shows the structure of the welding part vicinity at the time of using a wedge-shaped connection member. In the conventional example, it is a side view which shows the structure of the welding part vicinity at the time of using a stabilizer bar. In the conventional example, it is a side view which shows the structure of the welding part vicinity at the time of using a round steel. In the conventional example, it is a side view which shows the structure of the welding part vicinity at the time of using an iron powder. In the conventional example, it is a side view which shows the structure of the steel pipe sheet pile at the time of using a stabilizer bar.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1: has shown the outline of the structure of the steel pipe sheet pile manufacturing equipment 1 which manufactures the steel pipe sheet pile 100 concerning this Embodiment. In the steel pipe sheet pile manufacturing facility 1, a steel pipe sheet pile 100 including a main pipe 101 made of, for example, a spiral steel pipe (hereinafter sometimes simply referred to as “main pipe 101”) and a joint steel pipe 102 made of, for example, an electric resistance steel pipe is manufactured. . In the present embodiment, the main pipe 101 has, for example, a diameter of 500 mm to 1650 mm and a thickness of 6 mm to 25.4 mm. The joint steel pipe 102 has a diameter of, for example, 165.2 mm to 216.3 mm and a thickness of 9 mm to 11 mm.

  The steel pipe sheet pile manufacturing facility 1 includes a steel pipe sheet pile manufacturing line 10 and a joint steel pipe manufacturing line 11.

  The steel pipe sheet pile production line 10 is configured such that a main pipe 101 and a steel pipe sheet pile 100 in which the main pipe 101 is attached to the joint steel pipe 102 are conveyed in the Y direction. The main pipe 101 and the steel pipe sheet pile 100 are arranged and conveyed on the turning roll by a conveyance mechanism (not shown) so that the axial direction extends in the X direction.

  The steel pipe sheet pile production line 10 includes, for example, a pretreatment unit 20 that performs predetermined pretreatment on the main pipe 101, a tacking unit 21 that temporarily attaches the joint steel pipe 102 to the main pipe 101, and the main pipe 101 and the joint steel pipe. The main welding part 22 for welding 102 (hereinafter, the welding performed in the main welding part 22 may be referred to as “main welding”) and a steel pipe sheet pile 100 in which the main pipe 101 is attached to the joint steel pipe 102 are predetermined. A post-processing unit 23 that performs post-processing is arranged in this order.

  In the pre-processing unit 20, for example, a process of performing scoring on the main pipe 101 and centering, a process of adjusting the position of the main pipe 101, and the like are performed.

  The temporary attachment portion 21 is provided with a temporary attachment device 30 that temporarily welds the joint steel pipe 102 while being pressed down to the main pipe 101. The tacking device 30 is configured to be movable in the axial direction (X direction) of the main pipe 101 and the joint steel pipe 102.

  The main welding unit 22 is provided with a main welding device 31 for main welding the joint steel pipe 102 to the main pipe 101 along the axial direction. The main welding device 31 is configured to be movable in the axial direction (X direction) of the main pipe 101 and the joint steel pipe 102.

  In the post-processing unit 23, for example, a process of attaching a hanging bracket to the steel pipe sheet pile 100, a finishing process of forming the steel pipe sheet pile 100, a plasma process of forming a slit extending in the axial direction in the joint steel pipe 102, an inspection of the steel pipe sheet pile 100, a steel pipe Correction processing of the pipe end of the sheet pile 100 is performed.

  The joint steel pipe production line 11 is configured such that the joint steel pipe 102 is conveyed in the Y direction. The joint steel pipe 102 is disposed and transported on a turning roll by a transport mechanism (not shown) so that its axial direction extends in the X direction.

  The joint steel pipe production line 11 is provided with an attachment device 32 for welding and attaching a connecting member 200 described later to the joint steel pipe 102. The attachment device 32 is configured to be movable in the axial direction (X direction) of the joint steel pipe 102 and the connecting member 200. And the joint steel pipe 102 with which the connection member 200 was attached is conveyed by the temporary attachment part 21 of the steel pipe sheet pile production line 10 by the conveyance mechanism which is not shown in figure.

  Next, the manufacturing method of the steel pipe sheet pile 100 performed in the steel pipe sheet pile manufacturing equipment 1 comprised as mentioned above is demonstrated. In the steel pipe sheet pile manufacturing facility 1, the process in the steel pipe sheet pile manufacturing line 10 and the process in the joint steel pipe manufacturing line 11 are performed in parallel.

In the joint steel pipe production line 11, the connecting member 200 is attached to the joint steel pipe 102 as shown in FIG. The connecting member 200 extends in the axial direction (X direction) of the joint steel pipe 102. The cross-section of the connecting member 200 has a rectangular shape with a long side length H1 of ₁₀ mm to 19 mm and a short side length H2 of ₂ mm to 5 mm. That is, for example, a flat bar is used for the connecting member 200.

The connecting members 200 are arranged in pairs on both sides of the Z-direction center line C of the joint steel pipe 102. The connecting member 200 is arranged such that its long side (one side of the length H ₁ ) extends in the X direction and the short side (one side of the length H ₂ ) extends in the Z direction. And in a state where a pair of connecting members 200 and 200 are arranged to joint steel pipe 102 in this way, a pair of connecting members 200 and 200 are welded to joint steel pipe 102 by a pair of torches 40 and 40 of attachment device 32. At this time, the attachment device 32 is moved in the axial direction (X direction) of the joint steel pipe 102 to attach the pair of connecting members 200, 200 to the joint steel pipe 102 in the X direction. The joint steel pipe 102 to which the connecting member 200 is attached is conveyed to the temporary attachment part 21 of the steel pipe sheet pile production line 10.

  On the other hand, in the steel pipe sheet pile manufacturing line 10, first, the pretreatment described above is performed on the main pipe 101 in the pretreatment section 20. Thereafter, the main pipe 101 is conveyed to the temporary attachment unit 21.

  In the temporary attaching part 21, as shown in FIG. 3, the joint steel pipe 102 with which the connection member 200 was attached in the joint steel pipe manufacturing line 11 is arrange | positioned at a pair at the main pipe 101. That is, the pair of joint steel pipes 102 and 102 are arranged on both sides of the main pipe 101 so as to face the center of the main pipe 101.

  Then, the tacking device 30 is moved in the axial direction of the main pipe 101, and the joint steel pipe 102 is temporarily welded to the main pipe 101. At this time, as shown in FIG. 4, the connecting member 200 is disposed in a welded portion 120 where the main pipe 101 and the joint steel pipe 102 are welded. The welded portion 120 is provided in a pair with a center line C connecting the center of the main pipe 101 and the center of the joint steel pipe 102 interposed therebetween. And a pair of connection members 200 and 200 shown in Drawing 2 are arranged in a pair of these welding parts 120 and 120, respectively.

  As shown in FIG. 4, the connecting member 200 is disposed in contact with the outer surface of the main pipe 101. That is, the main pipe 101 and the joint steel pipe 102 abut or are arranged with a slight gap, but the connecting member 200 closes the tip of the welded portion 120 (near the place where the main pipe 101 and the joint steel pipe 102 abut). Are arranged as follows. And since temporary attachment of the joint steel pipe 102 in the temporary attachment part 21 is performed in the state which the connection member 200 surface-contacted with the outer surface of the main pipe 101, the said temporary attachment is stabilized.

  Thereafter, the main pipe 101 is reversed, and another joint steel pipe 102 is temporarily attached to the main pipe 101 by the tacking device 30. In this way, the pair of joint steel pipes 102 and 102 are temporarily attached to the main pipe 101.

  The main pipe 101 to which the joint steel pipe 102 is temporarily attached is conveyed to the main welding portion 22. In the main welding portion 22, as shown in FIG. 5, the pair of joint steel pipes 102 and 102 are arranged so as to be aligned in the horizontal direction (Y direction) with respect to the main pipe 101. And while moving the main welding apparatus 31 in the axial direction of the main pipe 101 with respect to the surface side of the main pipe 101 (Z direction positive direction side), the pair of torches 41, 41 of the main welding apparatus 31 can The steel pipe 102 and the connecting member 200 are finally welded to the outer surface of the main pipe 101. At this time, as shown in FIG. 6, since the connecting member 200 is provided so as to contact the main pipe 101 and the joint steel pipe 102 in the welded portion 120, molten metal does not sag and meltdown can be suppressed. Further, since the connecting member 200 is filled between the main pipe 101 and the joint steel pipe 102, the bead 210 is easily spread, and the width W of the bead 210 can be ensured to a required width, for example, 8 mm or more.

  Thereafter, the main pipe 101 is inverted, and the welded steel pipe 102 is main-welded to the back surface side (the Z direction negative direction side in FIG. 5) of the main pipe 101 by the main welding device 31. In this way, the pair of joint steel pipes 102 and 102 are main-welded to the main pipe 101.

  The main pipe 101 to which the joint steel pipe 102 is main-welded is transported to the post-processing unit 23, and the post-processing described above is performed. The steel pipe sheet pile 100 manufactured as described above is unloaded from the steel pipe sheet pile manufacturing facility 1, and a series of manufacturing steps of the steel pipe sheet pile 100 is completed.

  According to the above embodiment, since the connecting member 200 has a rectangular cross section, the connecting member 200 is disposed so as to close the tip of the welded portion 120. For this reason, when the welded steel pipe 102 and the connecting member 200 are finally welded to the main pipe 101 in the main welding portion 22, the molten metal does not sag and meltdown can be suppressed. In addition, by providing the connecting member 200, it is possible to prevent the molten metal from being melted into the main pipe 101 and the joint steel pipe 102. Further, since the connecting member 200 is filled between the main pipe 101 and the joint steel pipe 102, the width W of the bead 210 can be ensured to a desired width. Furthermore, since the main welding can be appropriately performed in this way, welding defects can be suppressed and undercutting can be suppressed. Therefore, according to this Embodiment, the quality of the steel pipe sheet pile 100 can be improved.

  Further, before the joint steel pipe 102 and the connecting member 200 are fully welded to the main pipe 101 in the steel pipe sheet pile manufacturing line 10, the connecting member 200 is attached to the joint steel pipe 102 in advance in the joint steel pipe manufacturing line 11. For this reason, it is not necessary to attach the connecting member 200 (in the conventional case, the round steel 121 shown in FIG. 9 or the iron powder 130 shown in FIG. 10) in the main welding portion 22 that regulates the manufacturing throughput, and the main welding is performed. This time can be shortened. Therefore, the manufacturing throughput of the steel pipe sheet pile 100 can be improved.

  Further, since the cross section of the connecting member 200 has a rectangular simple structure, the connecting member 200 can be easily designed and manufactured easily. Therefore, the manufacturing cost of the steel pipe sheet pile 100 can be reduced.

In addition, as a result of the intensive studies by the inventors, if the rectangular cross section of the connecting member 200 has a long side length H1 of ₁₀ mm to 19 mm and a short side length H2 of ₂ mm to 5 mm, the above-described case. It was found that the effect obtained can be obtained. Specifically, the length H ₁ of the long sides When 10Mm～19mm, it is possible to suppress the meltdown, also it is possible to ensure a width W of the bead 210 to the desired width. Further, when the short side length _{H 2} and 2 mm to 5 mm, allows properly inserted the connecting member 200 to the weld 120. And in order to acquire such an effect, it turns out that the rectangular cross section of this size is preferable irrespective of the diameter and thickness of the main pipe 101, and the diameter and thickness of the joint steel pipe 102.

  The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the idea described in the claims, and these naturally belong to the technical scope of the present invention. It is understood.

  Hereinafter, the manufacturing method of the steel pipe sheet pile of this invention and the effect of the steel pipe sheet pile manufactured by the said manufacturing method are demonstrated. In Example 1 concerning this invention, the steel pipe sheet pile 100 was manufactured with the manufacturing method shown in FIGS. 2-6 using the steel pipe sheet pile manufacturing equipment 1 shown in FIG. That is, in Example 1, the connecting member 200 having a rectangular cross section was used as the connecting member provided in the welded portion 120 between the main pipe 101 and the joint steel pipe 102.

  On the other hand, in Comparative Examples 1-4, the connection member provided in the welding part 120 was changed, and the steel pipe sheet pile 100 was manufactured. In Comparative Example 1, the stabilizer bar 110 was used as the connecting member as shown in FIG. In Comparative Example 2, as shown in FIG. 9, a pair of round steels 121 and 121 was used as the connecting member, and a round steel with a small diameter of less than 10 mm was used as the round steel 121. In Comparative Example 3, as shown in FIG. 9, a pair of round steels 121 and 121 is used as the connecting member, and a round steel bar having a large diameter of 10 mm or more is used as the round steel 121. In Comparative Example 4, as shown in FIG. 7, a pair of wedge-shaped connecting members 140 and 140 were used. The connecting member 140 is formed in a tapered shape toward the center side of the joint steel pipe 102 so as to follow the outer surface of the joint steel pipe 102. Such a connecting member 140 is not described in, for example, the above-described conventional documents 1 and 2, and is not a connecting member having a shape that has been conventionally used, but has been devised and studied by the inventors. .

  The results of manufacturing the steel pipe sheet pile 100 under the above conditions are shown in Table 1. In Table 1, the sheet pile width indicates the distance L between the joint steel pipes 102 and 102 provided on both sides of the main pipe 101 as shown in FIG. Melt down indicates the ratio of molten metal that has melted to the required bead. Undercut indicates the ratio of defect length to weld length. The cost indicates the manufacturing cost per unit length (1 m).

  Referring to Table 1, in Comparative Example 1, the sheet pile width of the steel pipe sheet pile 100 exceeded the specification tolerance due to the provision of the stability bar 110. Moreover, when the stabilizer bar 110 was used, welding of the main pipe 101 and the joint steel pipe 102 became difficult, and the undercut increased. Furthermore, the manufacturing cost of the steel pipe sheet pile 100 increased because the stability bar 110 was large.

  In the comparative example 2, since the round steel 121 has a small diameter, the meltdown in which the weld metal melts largely occurred.

  In Comparative Example 3, since the round steel 121 has a large diameter, the tip of the round steel 121 fits into the welded portion 120 and a defect (undercut) occurs. Moreover, the manufacturing cost of the steel pipe sheet pile 100 became high because the round steel 121 was large.

  In Comparative Example 4, since the forming process of the wedge-shaped connecting member 140 is complicated, the manufacturing cost of the steel pipe sheet pile 100 is increased.

  On the other hand, according to Example 1, it turned out that the sheet pile width | variety of the steel pipe sheet pile 100 can be ensured appropriately, meltdown and undercut can be suppressed, and also the manufacturing cost of the steel pipe sheet pile 100 can be reduced.

  The present invention is useful when manufacturing a steel pipe sheet pile including a steel pipe sheet pile main pipe and a joint steel pipe.

DESCRIPTION OF SYMBOLS 1 Steel pipe sheet pile manufacturing equipment 10 Steel pipe sheet pile manufacturing line 11 Joint steel pipe manufacturing line 20 Pretreatment part 21 Temporary attachment part 22 Main welding part 23 Post-treatment part 30 Temporary attachment apparatus 31 Main welding apparatus 32 Mounting apparatus 40 Torch 41 Torch 100 Steel pipe sheet pile 101 Main pipe 102 Joint steel pipe 120 Welded part 200 Connecting member 210 Bead

Claims (5)

A steel pipe sheet pile main pipe, and a steel pipe sheet pile manufacturing method comprising a joint steel pipe provided along the axial direction on the outer surface of the steel pipe sheet pile main pipe,
A first connecting member extending in the axial direction of the joint steel pipe and having a rectangular cross section is provided on the outer surface of the joint steel pipe along the axial direction and on both sides of the center line of the joint steel pipe. Process,
Then, a second step of welding the pair of connecting members and the joint steel pipe to the outer surface of the steel pipe sheet pile main pipe, a method for manufacturing a steel pipe sheet pile. The method for manufacturing a steel pipe sheet pile according to claim 1, wherein the first step and the second step are performed in separate manufacturing lines. 3. The steel pipe sheet pile according to claim 1, wherein the cross-section of the connecting member has a rectangular shape having a length of one side of 10 mm to 19 mm and a length of the other side of 2 mm to 5 mm. Production method. A steel pipe sheet pile comprising a steel pipe sheet pile main pipe and a joint steel pipe provided by welding along the axial direction on the outer surface of the steel pipe sheet pile main pipe,
Between the steel pipe sheet pile main pipe and the joint steel pipe, a pair of welding the steel pipe sheet pile main pipe and the joint steel pipe with a center line connecting the center of the steel pipe sheet pile main pipe and the center of the joint steel pipe sandwiched therebetween. A weld is formed,
A steel pipe sheet pile, wherein the welded part is provided with a connecting member extending along the axial direction of the joint steel pipe and having a rectangular cross section. 5. The steel pipe sheet pile according to claim 4, wherein a cross-section of the connecting member has a rectangular shape having a length of one side of 10 mm to 19 mm and a length of the other side of 2 mm to 5 mm.

Images