Steel pipe joint structure of steel slit dam and steel slit dam

Abstract

To provide a steel pipe joint structure of a steel slit dam with high workability, strength, rigidity, economical efficiency, and maintainability, in which a new steel pipe joint structure replacing a flange joint (a flange plate and a high-strength bolt) is developed to realize a joint structure with higher strength and rigidity than those of the flange joint without using high-strength bolts, thereby eliminating the need for bolt tightening management and minimizing damage and destruction of members due to direct hits of gravel, and to provide a steel slit dam comprising the steel pipe joint structure.SOLUTION: A first joint member 1 comprising an uneven portion 11 forming uneven steps in an axial direction of a steel pipe 10 is provided at an end of the steel pipe 10. A second joint member 2 comprising an uneven portion 22 engaging with the uneven portion 11 of the first joint member 1 is provided at an end of the other steel pipe 20. A slip-off prevention member 3 is joined at an engaging portion R between the uneven portion 22 of the first joint member 1 and the uneven portion 22 of the second joint member 2.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention belongs to the technical field of steel pipe joint structures for steel slit dams, and more specifically, to the technical field of joint structures for the joints between steel pipes that constitute a steel slit dam, which is mainly installed between concrete embankments on both banks of a river in the transverse direction. [Background technology]

[0002] Steel slit dams are well known, erected between concrete embankments on both banks of a river in the cross direction, and used as debris flow capture measures or driftwood capture measures to effectively capture floating debris such as boulders or driftwood.

[0003] This steel slit dam is also called a steel permeable sabo dam, and various shapes and structures of the technology have been disclosed and put into practice to date. However, the joint structure of the joints between the steel pipes that make up the steel slit dam is mainly a connecting means (hereinafter referred to as a flange joint) using a steel plate (hereinafter referred to as a flange plate) and a fastening bolt (hereinafter referred to as a high-strength bolt), as shown in Patent Documents 1 to 3, for example. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-40073 [Patent Document 2] Japanese Patent Application Laid-Open No. 2017-40074 [Patent Document 3] Japanese Patent Application Publication No. 2017-40081 Summary of the Invention [Problem to be solved by the invention]

[0005] When the external force acting on the steel slit dam becomes large, the thickness of the flange plate becomes thicker and many high-strength bolts are required, making it practically difficult to manufacture flange joints, and in some cases, there are problems with structural design that make flange joints insufficient to cope with the problem. In addition, in current flange joints, the high-strength bolts (bolt heads and nuts) are exposed, so if, for example, gravel hits the joint (connection), the high-strength bolt will break, which will accelerate the destruction of the joint, and ultimately lead to damage and destruction of the entire steel slit dam structure. Furthermore, when tightening the high-strength bolts used in flange joints, on-site bolt tightening control (torque control, temperature control) is required, which makes assembly work complicated.

[0006] The present invention was devised in consideration of the problems of the background art described above, and its purpose is to develop a new steel pipe joint structure to replace the flange joints (flange plates and high-strength bolts), thereby realizing a joint structure that is stronger and more rigid than the flange joints without using high-strength bolts, thereby making the bolt tightening management unnecessary and minimizing damage and destruction to components caused by direct hits of gravel as much as possible, and to provide a steel pipe joint structure for a steel slit dam and a steel slit dam equipped with the steel pipe joint structure that is easy to construct, strong and rigid, economical, and maintainable. [Means for solving the problem]

[0007] As a means for solving the above problems, the steel pipe joint structure of a steel slit dam according to the invention described in claim 1 is a joint structure of a joint between steel pipes that constitute a steel slit dam, in which one of the steel pipes of A first joint member is provided at the end of the steel pipe, and the first joint member has an uneven portion that forms uneven steps in the axial direction of the steel pipe. of A second joint member is provided at an end thereof with a convexo-concave portion that engages with the concave-convex portion of the first joint member. Being, The concave and convex portions of the first joint member are joined A plurality of parallel grooves extending in a direction perpendicular to the axial direction of the steel pipe are formed in the width direction of the first joint member. The concave and convex portions of the second joint member are formed by a plurality of parallel grooves extending in a direction perpendicular to the axial direction of the steel pipes to be joined in the width direction of the second joint member; The plurality of parallel grooves formed in the first joint member and the second joint member have a plurality of through holes formed therein that penetrate groove walls of the respective grooves, An engagement portion between the concave-convex portion of the first joint member and the convex-convex portion of the second joint member By passing the retaining member through the through hole in a skewer shape, It is characterized by being joined.

[0010] Claim 2 The invention described in claim 1 In the steel pipe joint structure of the steel slit dam described in 2, the first joint member and the second joint member are each provided at the end of the corresponding steel pipe and have a disk-shaped or rectangular base end plate portion that is large enough to protrude outward from the steel pipe, and a base end plate portion that rises from the base end plate portion. The groove The present invention is characterized in that it comprises a wall portion.

[0011] Claim 3 The invention described in claim 1 or 2 In the steel pipe joint structure of the steel slit dam described in groove The wall portion is characterized by being formed in a tapered shape that narrows in the rising direction.

[0012] Claim 4 The invention described in claim 2 or 3 In the steel pipe joint structure of the steel slit dam described in 2., the base end plate portion of the first joint member and the base end plate portion of the second joint member each have the retaining member attached to the steel pipe of It is characterized by being set to a size that covers the entire area when viewed from the axial direction.

[0013] Claim 5 The steel slit dam according to the invention described in claims 1 to 4 The present invention is characterized in that it is provided with the steel pipe joint structure described in any one of the above items. [Effects of the Invention]

[0014] The steel pipe joint structure for a steel slit dam and the steel slit dam equipped with the steel pipe joint structure according to the present invention have the following advantageous effects. (1) The interlocking effect between the concave and convex portions of the first joint member and the convex and concave portions of the second joint member (interlocking joint) makes it possible to easily and reliably realize a steel pipe joint structure that is stronger and more rigid than conventional flange joints. Accordingly, if the external force acting on the steel slit dam becomes large, with conventional flange joints, the flange plate thickness becomes thicker and many high-strength bolts are required, making it practically difficult to manufacture the flange joint, and in some cases, there are problems with the structural design that make it impossible for flange joints to cope with the situation.However, with the steel pipe joint structure of the present invention, flange plates and high-strength bolts are not used, so it can adequately cope even when the external force acting on the steel slit dam becomes large. Furthermore, tightening the high-strength bolts used in conventional flange joints requires on-site bolt tightening management (torque management, temperature management), which is troublesome and cumbersome. However, the steel pipe joint structure of the present invention does not use high-strength bolts, so the bolt tightening management is unnecessary, and is therefore extremely easy to install, economical, and maintainable. Furthermore, compared to conventional flange joints, the interlocking effect of the heavy, strong, and rigid structure created by the concave and convex parts of the first joint member and the concave and convex parts of the second joint member dramatically increases the shear resistance and bending resistance of the steel pipe joint, making it possible to minimize opening or misalignment due to impacts from boulders, etc. (2) In conventional flange joints, the high-strength bolts (bolt heads and nuts) are exposed. Therefore, if gravel strikes the joint (joint), the high-strength bolts break, which can accelerate the destruction of the joint and ultimately lead to damage and destruction of the entire steel slit dam structure. However, the steel pipe joint structure of the present invention does not use high-strength bolts, so the problems associated with the use of high-strength bolts as described above do not occur. In addition, since high-strength bolts are not used, this contributes to reducing the labor required for on-site work and shortening the construction period. (3) In addition, according to the invention of claim 6 (see Examples 2 and 3), the retaining member that maintains the engagement between the first and second coupling members can be protected from gravel, thereby preventing damage and destruction of the retaining member (steel pipe joint). This ultimately realizes a steel slit dam that is stable and safe, maintaining the required strength and rigidity for a specified service life, and can also cope with the increasing scale of debris flows in recent years and the collision of debris flows and boulders of an unexpected scale. (4) In summary, by developing a new steel pipe joint structure to replace conventional flange joints (flange plates and high-strength bolts), it is possible to realize a joint structure that is stronger and more rigid than the flange joints without using high-strength bolts, thereby making the bolt tightening management unnecessary and minimizing damage and destruction to components caused by direct hits of gravel. This makes it possible to realize a steel pipe joint structure for a steel slit dam and a steel slit dam equipped with the steel pipe joint structure that is easy to construct, strong, rigid, economical, and maintainable. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a perspective view showing a steel pipe joint portion of a steel pipe joint structure of a steel slit dam according to Example 1. FIG. [Figure 2] FIG. 3 is a perspective view showing a first joint member at one steel pipe end and a second joint member at the other steel pipe end in the steel pipe joint. [Figure 3] 1 is a longitudinal cross-sectional view showing a steel pipe joint portion of a steel pipe joint structure of a steel slit dam according to Example 1. FIG. [Figure 4] FIG. 1 is a front view showing a steel pipe joint portion of a steel pipe joint structure of a steel slit dam according to a first embodiment. [Figure 5] FIG. 4 is a perspective view showing a first joint member in the steel pipe joint. [Figure 6] FIG. 4 is a perspective view showing a second joint member in the steel pipe joint. [Figure 7] FIG. 10 is a perspective view showing a steel pipe joint portion of a steel pipe joint structure of a steel slit dam according to Example 2. [Figure 8]FIG. 3 is a perspective view showing a first joint member at one steel pipe end and a second joint member at the other steel pipe end in the steel pipe joint. [Figure 9] FIG. 10 is a longitudinal cross-sectional view showing a steel pipe joint portion of a steel pipe joint structure of a steel slit dam according to Example 2. [Figure 10] FIG. 10 is a front view showing a steel pipe joint portion of a steel pipe joint structure of a steel slit dam according to Example 2. [Figure 11] FIG. 4 is a perspective view showing a first joint member in the steel pipe joint. [Figure 12] FIG. 4 is a perspective view showing a second joint member in the steel pipe joint. [Figure 13] FIG. 10 is a perspective view showing a steel pipe joint portion of a steel pipe joint structure of a steel slit dam according to Example 3. [Figure 14] FIG. 3 is a perspective view showing a first joint member at one steel pipe end and a second joint member at the other steel pipe end in the steel pipe joint. [Figure 15] FIG. 10 is a longitudinal cross-sectional view showing a steel pipe joint portion of a steel pipe joint structure of a steel slit dam according to Example 3. [Figure 16] FIG. 10 is a front view showing a steel pipe joint portion of a steel pipe joint structure of a steel slit dam according to Example 3. [Figure 17] FIG. 4 is a perspective view showing a first joint member in the steel pipe joint. [Figure 18] FIG. 4 is a perspective view showing a second joint member in the steel pipe joint. DETAILED DESCRIPTION OF THE INVENTION

[0016] This invention is based on a technical idea that can realize a steel pipe joint structure that is stronger and more rigid than conventional flange joints, more simply and reliably than conventional flat joints, in a steel pipe joint structure for a steel slit dam, specifically, in the joint structure of the joint between steel pipes that make up a steel slit dam that is mainly installed between concrete embankments on both banks of a river in the transverse direction. The drawings used to explain the embodiments show a steel pipe joint structure for joining in the vertical direction as an example, but of course the present invention is not limited to this. The steel pipe joint structure of the present invention can be applied to any location without directionality, and can be appropriately extended and joined in any direction, such as horizontally, vertically, or inclined, to construct a three-dimensional steel slit dam. However, the steel pipe joint structure of the present invention may be applied to all steel pipe joints to construct a steel slit dam, or may be applied to only some steel pipe joints (for example, only steel pipe joints installed on the upstream side) to construct a steel slit dam. Many variations in implementation are possible. Hereinafter, an embodiment of a steel pipe joint structure for a steel slit dam according to the present invention will be described with reference to the drawings. [Example]

[0017] As shown in Figures 1 to 6, the steel pipe joint structure of the steel slit dam according to Example 1 is a joint structure for the joint between steel pipes that constitute the steel slit dam, and is implemented as follows: a first joint member 1 is provided at the end of one steel pipe 10, with an uneven portion 11 that forms uneven steps in the axial direction of the steel pipe 10; and a second joint member 2 is provided at the end of the other steel pipe 20, with an uneven portion 22 that engages with the uneven portion 11 of the first joint member 1; and a retaining member 3 is joined to the engaging portion R (see Figure 3) between the uneven portion 11 of the first joint member 1 and the uneven portion 22 of the second joint member 2.

[0018] In this embodiment 1, a metal rod-shaped key or pin is preferably used as the anti-slip member 3, and multiple (six in the illustrated example) anti-slip members 3 of different lengths depending on the joining location are pierced through the interlocking portion R in a skewer-like manner and joined. In this Example 1, the uneven portion 11 of the first joint part 1 and the uneven portion 22 of the second joint part 2 each have a plurality of parallel grooves 11a, 22a formed at approximately equal intervals and extending in a direction perpendicular to the axial direction of the steel pipes 10, 20, and through holes 11c, 22c for inserting the retaining member 3 are formed in groove walls 11b, 22b of the grooves 11a, 22a. Both of the through holes 11c, 22c in this Example 1 have approximately the same shape and size (a square of approximately 50 × 50 mm) as the cross section of the retaining member 3, and are implemented in a form that allows the retaining member 3 to be inserted smoothly or with slight frictional resistance.

[0019] In this embodiment 1, the first coupling part 1 and the second coupling part 2 each comprise a disk-shaped base end plate part 1a, 2a provided at the end of the corresponding steel pipe 10, 20 and sized to protrude outward from the steel pipe 10, 20, and a rising wall part 1b, 2b rising from the base end plate part 1a, 2a. In this embodiment 1, the rising wall part 1b, 2b is formed in a tapered shape that narrows in width in the rising direction. Incidentally, the reference symbols 1a' and 2a' in the drawing respectively denote ring-shaped protrusions for realizing a satisfactory welding joint by butting the base end plate portions 1a and 2a concentrically to the ends of the corresponding steel pipes 10 and 20. Note that the means for satisfactory concentrically joining the base end plate portions 1a and 2a to the ends of the steel pipes 10 and 20 is not limited to welding, and bolt jointing or screw jointing can also be used.

[0020] The first coupling member 1 is previously integrally welded to the joining end edge of one of the steel pipes 10 (the upper one in the illustrated example) in a concentric arrangement via the ring-shaped protruding portion 1a' by the welding means (circumferential welding) (the weld bead is omitted for convenience of illustration). The second coupling member 2 is previously integrally welded to the joining end edge of the other of the steel pipes 20 (the lower one in the illustrated example) in a concentric arrangement via the ring-shaped protruding portion 2a' by the welding means (circumferential welding) (the weld bead is omitted for convenience of illustration).

[0021] Here, the configuration of the components of the steel pipe joint structure according to the present invention will be explained. First, the steel pipes 10, 20 are modified as appropriate depending on the structural design, but generally have an outer diameter (φ) of approximately 400 to 600 mm and a plate thickness (t) of approximately 9 to 22 mm. However, it is preferable that the sizes (cross-sectional sizes) of the steel pipes 10, 20 to be joined are the same. Specifically, the steel pipes 10, 20 used in Example 1 both have an outer diameter of approximately 400 mm and a plate thickness of approximately 18 mm. The same technical concept applies to Examples 2 and 3 below.

[0022] Next, in this Example 1, the disk-shaped base end plate portion 1a constituting the first joint member 1 has an outer diameter of approximately 550 mm, a plate thickness (see symbol T1) of approximately 32 mm, and a ring-shaped protruding portion 1a' of approximately 30 mm in height. As shown in FIG. 3 , six of the rising wall portions 1b are formed at approximately equal intervals, and each has an inverted trapezoidal cross section with an upper side of approximately 47 mm, a lower side of approximately 55 mm, and a height (see symbol R) of approximately 125 mm. The depth direction lengths of the six rising wall portions 1b are set so that they do not extend beyond the outer periphery of the disk-shaped base end plate portion 1a, and therefore the lengths decrease outward from the center of FIG. 3 to the left and right. The total weight of the first joint member 1, including the base end plate portion 1a and the rising wall portions 1b, is approximately 246 kg. For example, SCW550 steel is used as the steel casting for welded structures.

[0023] Next, in this Example 1, the disk-shaped base end plate portion 2a constituting the second joint member 2 has an outer diameter of approximately 550 mm, a plate thickness (see symbol T2) of approximately 32 mm, and a ring-shaped protruding portion 2a' of approximately 30 mm in height. As shown in FIG. 3 , five of the upstanding wall portions 2b are formed at approximately equal intervals, each with a trapezoidal cross section having an upper edge of approximately 47 mm, a lower edge of approximately 55 mm, and a height (see symbol R) of approximately 125 mm. The depth direction lengths of the five upstanding wall portions 2b are set so that they do not extend beyond the outer periphery of the disk-shaped base end plate portion 2a, and therefore the lengths decrease outward from the center of FIG. 3 to the left and right. The total weight of the second joint member 2, including the base end plate portion 2a and the upstanding wall portions 2b, is approximately 243 kg. For example, SCW550 steel is used as the steel casting for welded structures.

[0024] Next, in this Example 1, the retaining members 3 are implemented as multiple (six in the illustrated example) metal rods whose cross sections have a uniform rectangular cross-sectional shape (approximately the same shape and size as the cross sections of the through holes 11c, 22c) and whose lengths vary depending on the parts to be skewered through the through holes 11c, 22c. Incidentally, the six retaining members 3 according to this Example 1 are approximately 570 mm in length at the longest and 300 mm in length at the shortest, with a total weight of approximately 68 kg for the six members.

[0025] It should be noted that the numerical values ​​such as the sizes of the components of the steel pipe joint structure according to Example 1 described in the above paragraphs

[0021] to

[0024] are merely examples and can be increased or decreased as appropriate depending on the structural design.

[0026] Therefore, in the steel pipe joint structure of the steel slit dam according to Example 1, when steel pipes are joined together horizontally, vertically, or inclined as needed to construct a three-dimensional steel slit dam, a steel pipe 10 equipped with the first joint member 1 and a steel pipe 20 equipped with the second joint member 2 are opposed to each other, and alignment work is performed as needed, such as butting or sliding the uneven portion 11 of the first joint member 1 against the uneven portion 22 of the second joint member 2, until the uneven portion 11 and the uneven portion 22 are meshed (overlapping without gaps in the illustrated example), and fine adjustment work is performed so that the centers of the alternatingly arranged through holes 11c of the uneven portion 11 and the through holes 22c of the uneven portion 22 are approximately aligned to form a connected state. As a result, in Example 1, a total of six long and short rectangular tubular through holes consisting of the through holes 11c and 22c are formed. Thereafter, the six anti-slip members 3 of different lengths are passed through the six long and short through-holes, respectively, and positioned using a fall-off prevention member such as a split pin as necessary, thereby firmly maintaining the meshing state between the concave-convex portion 11 of the first joint member 1 and the convex-convex portion 22 of the second joint member 2, thereby achieving a steel pipe joint structure for a steel slit dam using the first joint member 1 and the second joint member 2 that has high strength and rigidity.

[0027] In addition, the concave-convex portion 11 and the concave-convex portion 22 according to this Example 1 are implemented by forming the groove walls 11b, 22b in a tapered shape to achieve good engagement, but this is not limited to this, and they can also be formed in straight lines parallel to the axial direction of the steel pipe. In addition, measures such as rounding the corners of the retaining member 3 over the entire length can be taken as appropriate to make the insertion into the through holes 11c, 22c smoother.

[0028] Therefore, according to the steel pipe joint structure of the steel slit dam of Example 1, the meshing effect between the concave-convex portion 11 of the first joint member 1 and the convex-convex portion 22 of the second joint member 2 makes it possible to easily and reliably realize a steel pipe joint structure that is stronger and more rigid than conventional flange joints, and various other effects can be exhibited (for details, see "Effects of the Invention" in paragraph

[0014] of the specification). [Example]

[0029] The steel pipe joint structure of the steel slit dam according to Example 2 differs from that of Example 1 above in the configuration (size and shape) of the first joint member 1 and the second joint member 2. Accordingly, the configuration of each of the retaining members 3 is also different. The other components are the same as those of Example 1 above, so the same reference numerals are used and their description will be omitted as appropriate.

[0030] That is, as shown in Figs. 7 to 12, the steel pipe joint structure of the steel slit dam according to Example 2 is a joint structure of the joint between steel pipes that constitute the steel slit dam, in which a first joint member 4 having an uneven portion 44 that forms uneven steps in the axial direction of the steel pipe 10 is provided at the end of one steel pipe 10, and a second joint member 5 having an uneven portion 55 that engages with the uneven portion 44 of the first joint member 4 is provided at the end of the other steel pipe 20, and a stopper member 6 is joined to the engaging portion R (see Fig. 9) between the uneven portion 44 of the first joint member 4 and the uneven portion 55 of the second joint member 5.

[0031] In this embodiment 2, a metal rod-shaped key or pin is preferably used as the anti-slip member 6, and multiple (six in the illustrated example) anti-slip members 6 of equal length are inserted through the interlocking portion R in a skewer-like manner to join them depending on the joining location. In this Example 2, the uneven portion 44 of the first joint part 4 and the uneven portion 55 of the second joint part 5 are each formed with a plurality of parallel grooves 44a, 55a that extend in a direction perpendicular to the axial direction of the steel pipes 10, 20, at approximately equal intervals, and through holes 44c, 55c for inserting the retaining member 6 are formed in groove wall portions 44b, 55b of the grooves 44a, 55a. Both of the through holes 44c, 55c in this Example 2 have approximately the same shape and size as the cross section of the retaining member 6 (a square of approximately 42 × 42 mm), and are implemented in a form that allows the retaining member 6 to be inserted smoothly or with slight frictional resistance.

[0032] In this Example 2, the first joint part 4 and the second joint part 5 each comprise a rectangular (square) base end plate part 4a, 5a that is provided at the end of the corresponding steel pipe 10, 20 and that protrudes outward from the steel pipe 10, 20, and a rising wall part 4b, 5b that rises from the base end plate part 4a, 5a. In this Example 2, the rising wall part 4b, 5b is formed in a tapered shape that narrows in width in the rising direction. Incidentally, the reference symbols 4a' and 5a' in the drawing respectively denote ring-shaped protrusions for realizing a satisfactory welding joint by butting the base end plate portions 4a and 5a in a concentric arrangement to the ends of the corresponding steel pipes 10 and 20. Note that the means for satisfactory joining of the base end plate portions 4a and 5a in a concentric arrangement to the ends of the steel pipes 10 and 20 is not limited to welding, and bolt joining means or screw joining means can also be used.

[0033] The first coupling member 4 is previously welded to the joining end edge of one of the steel pipes 10 (the upper one in the illustrated example) in a concentric arrangement via the ring-shaped protruding portion 4a' by the welding means (full circumference welding) (the weld bead is omitted for convenience of illustration). The second coupling member 5 is previously welded to the joining end edge of the other of the steel pipes 20 (the lower one in the illustrated example) in a concentric arrangement via the ring-shaped protruding portion 5a' by the welding means (full circumference welding) (the weld bead is omitted for convenience of illustration).

[0034] Here, the configuration of the components of the steel pipe joint structure according to the present invention will be explained. First, the steel pipes 10, 20 are as explained in the first embodiment (see paragraph

[0021] above).

[0035] Next, in this Example 2, the rectangular base end plate portion 4a constituting the first joint member 4 has an outer diameter of approximately 550 × 550 mm (with notches at the four corners), a plate thickness (see symbol T4) of approximately 36 mm, and a ring-shaped protrusion 4a' of approximately 30 mm in height. As shown in FIG. 9 , four upstanding wall portions 4b are formed at approximately equal intervals, each with an inverted trapezoidal cross section with an upper side of approximately 64 mm, a lower side of approximately 72 mm, and a height (see symbol R) of approximately 83 mm. The depth direction length of each of the four upstanding wall portions 4b is approximately 550 mm, which corresponds to the length of one side of the base end plate portion 4a. The total weight of the first joint member 4, including the base end plate portion 4a and the upstanding wall portions 4b, is approximately 200 kg. For example, SCW550 steel is used as a welded cast steel product.

[0036] Next, in Example 2, the rectangular base end plate portion 5a constituting the second joint member 5 has an outer diameter of approximately 550 × 550 mm (with notches at the four corners), a plate thickness (see symbol T5) of approximately 36 mm, and a ring-shaped protrusion 5a' height of approximately 30 mm. As shown in FIG. 9 , three rising wall portions 5b are formed at approximately equal intervals, and each has a trapezoidal cross section with an upper side of approximately 64 mm, a lower side of approximately 72 mm, and a height (see symbol R) of approximately 83 mm. The depth length of each of the three rising wall portions 5b is approximately 550 mm, which corresponds to the length of one side of the base end plate portion 5a. The total weight of the second joint member 5, including the base end plate portion 5a and the rising wall portions 5b, is approximately 177 kg, and SCW550 steel is used as an example of a welded structural cast steel product.

[0037] Next, in this embodiment 2, the anti-pullout member 6 is implemented as a plurality (six in the illustrated example) of metal rods having an equal rectangular cross-sectional shape that is approximately the same shape and size (square of approximately 42 x 42 mm) as the cross-section of the through holes 44c, 55c, and having an equal length (approximately 550 mm) that penetrates the through holes 44c, 55c in a skewer-like manner. That is, in Example 2, the length of the retaining member 6 is set to be approximately the same as or slightly shorter (for example, about 550 mm) than the lengths of the base end plate portion 4a of the first coupling part 4 and the base end plate portion 5a of the second coupling part 5, thereby achieving a structure that prevents large gravel from colliding (directly hitting) with the retaining member 6. In other words, the base end plate portion 4a of the first coupling part 4 and the base end plate portion 5a of the second coupling part 5 are set to a size that covers the retaining member 6 when viewed in the axial direction of the steel pipes 10, 20, and thereby serve as a protective plate that protects the retaining member 6 from gravel. Incidentally, the total weight of the six retaining members 6 according to the first embodiment is approximately 50 kg.

[0038] It should be noted that the numerical values ​​such as the size of the components of the steel pipe joint structure according to Example 2 described in the above paragraphs

[0035] to

[0037] are merely examples and can be increased or decreased as appropriate depending on the structural design.

[0039] Therefore, in the steel pipe joint structure of the steel slit dam according to Example 2, when steel pipes are joined together horizontally, vertically, or inclined as needed to construct a three-dimensional steel slit dam, the steel pipe 10 equipped with the first joint member 4 and the steel pipe 20 equipped with the second joint member 5 are opposed to each other, and alignment work is performed as needed by butting or sliding the uneven portion 44 of the first joint member 4 against the uneven portion 55 of the second joint member 5, so that the uneven portion 44 and the uneven portion 55 are meshed (overlapped without gaps in the illustrated example), and fine adjustment work is performed so that the centers of the alternatingly arranged through holes 44c of the uneven portion 44 and the through holes 55c of the uneven portion 55 are approximately aligned to achieve a communicating state. As a result, in Example 2, a total of six rectangular tubular through holes of equal length (approximately 550 mm) consisting of the through holes 44c, 55c are formed. Thereafter, the six anti-slip members 6 are passed through the six through holes, respectively, and positioned using a fall-off prevention member such as a split pin, if necessary, thereby firmly maintaining the meshing state between the concave-convex portions 44 of the first joint member 4 and the convex-convex portions 55 of the second joint member 5, thereby achieving a steel pipe joint structure for a steel slit dam using the first joint member 4 and the second joint member 5, which has high strength and rigidity.

[0040] In addition, the uneven portion 44 and the concave and convex portions 55 according to this Example 2 are implemented by forming the groove wall portions 44b, 55b in a tapered shape to achieve good engagement, as in Example 1, but this is not limitative and they can also be formed in straight lines parallel to the axial direction of the steel pipe. In addition, measures such as rounding the corners of the retaining member 6 over its entire length can be taken as appropriate to make the insertion into the through holes 44c, 55c smoother.

[0041] Therefore, according to the steel pipe joint structure of the steel slit dam of Example 2, in addition to having the same effects as those of Example 1 above, it can be implemented with a structure that protects the anti-slip member 6 that maintains the interlocking state between the first joint member 4 and the second joint member 5 from gravel, and therefore it is possible to prevent damage and destruction of the anti-slip member 6 (steel pipe joint), and various other effects can be exhibited (for details, see [Effects of the Invention] in paragraph

[0014] of the specification). [Example]

[0042] The steel pipe joint structure of the steel slit dam according to Example 3 differs from that of Example 1 above in the configuration (size and shape) of the first joint part 1 and the second joint part 2. Accordingly, the configuration of each of the retaining members 3 is also different. The other components are the same as those of Example 1 above, so the same reference numerals are used and their description will be omitted as appropriate.

[0043] That is, as shown in Figures 13 to 18, the steel pipe joint structure of the steel slit dam according to Example 3 is a joint structure of the joint between steel pipes that constitute the steel slit dam, and is implemented as follows: a first joint member 7 having an uneven portion 77 that forms uneven steps in the axial direction of the steel pipe 10 is provided at the end of one steel pipe 10, and a second joint member 8 having an uneven portion 88 that engages with the uneven portion 77 of the first joint member 7 is provided at the end of the other steel pipe 20, and a stopper member 9 is joined to the engaging portion R (see Figure 15) between the uneven portion 77 of the first joint member 7 and the uneven portion 88 of the second joint member 8.

[0044] In this embodiment 3, a metal rod-shaped key or pin is preferably used as the anti-slip member 9, and multiple (six in the illustrated example) anti-slip members 9 of equal length are inserted through the interlocking portion R in a skewer-like manner to join them depending on the joining location. In this Example 3, the uneven portion 77 of the first joint part 7 and the uneven portion 88 of the second joint part 8 are each formed with a plurality of parallel grooves 77a, 88a that extend in a direction perpendicular to the axial direction of the steel pipes 10, 20, at approximately equal intervals, and through holes 77c, 88c for inserting the retaining member 9 are formed in groove wall portions 77b, 88b of the grooves 77a, 88a. Both of the through holes 77c, 88c according to this Example 3 have approximately the same shape and size as the cross section of the retaining member 9 (a square of approximately 45 × 45 mm), and are implemented in a form that allows the retaining member 9 to be inserted smoothly or with slight frictional resistance.

[0045] In this Example 3, the first coupling part 7 and the second coupling part 8 each comprise a rectangular (square) base end plate part 7a, 8a that is provided at the end of the corresponding steel pipe 10, 20 and that protrudes outward from the steel pipe 10, 20, and a rising wall part 7b, 8b that rises from the base end plate part 7a, 8a. In this Example 3, the rising wall part 7b, 8b is formed in a tapered shape that narrows in width in the rising direction. Incidentally, the reference numerals 7a' and 8a' in the figure respectively denote ring-shaped protrusions for butting the base end plate portions 7a and 8a concentrically against the ends of the corresponding steel pipes 10 and 20 to achieve a satisfactory welding joint. However, the shape of the ring-shaped protrusions 7a' and 8a' is different from that of the tapered rings in Examples 1 and 2, and the upper surfaces are formed flat. Note that the means for satisfactory concentrically joining the base end plate portions 7a and 8a to the ends of the steel pipes 10 and 20 is not limited to welding, and bolt joining or screw joining can also be used.

[0046] The first coupling member 7 is previously provided integrally with the joining end edge of one of the steel pipes 10 (the upper one in the illustrated example) by the welding means (full circumference welding) in a concentric arrangement via the ring-shaped protruding portion 7a' (the weld bead is omitted for convenience of illustration). The second coupling member 8 is previously provided integrally with the joining end edge of the other of the steel pipes 20 (the lower one in the illustrated example) by the welding means (full circumference welding) in a concentric arrangement via the ring-shaped protruding portion 8a' (the weld bead is omitted for convenience of illustration).

[0047] Here, the configuration of the components of the steel pipe joint structure according to the present invention will be explained. First, the steel pipes 10, 20 are as explained in the first embodiment (see paragraph

[0021] above).

[0048] Next, in Example 3, the rectangular base end plate portion 7a constituting the first joint member 7 has an outer diameter of approximately 550 × 550 mm (with notches at the four corners), a plate thickness (see symbol T7) of approximately 40 mm, and a ring-shaped protrusion 7a' of approximately 9 mm in height. As shown in FIG. 15 , four upstanding wall portions 7b are formed at approximately equal intervals, each with an inverted trapezoidal cross section with an upper edge of approximately 60 mm, a lower edge of approximately 72 mm, and a height (see symbol R) of approximately 120 mm. The depth direction length of each of the four upstanding wall portions 7b is approximately 550 mm, which corresponds to the length of one side of the base end plate portion 7a. The total weight of the first joint member 7, including the base end plate portion 7a and the upstanding wall portions 7b, is approximately 185.8 kg, and SCW550 steel is used as an example of a welded structural cast steel.

[0049] Next, in Example 3, the rectangular base end plate portion 8a constituting the second joint member 8 has an outer diameter of approximately 550 × 550 mm (with notches at the four corners), a plate thickness (see symbol T8) of approximately 40 mm, and a ring-shaped protrusion 8a' of approximately 9 mm in height. As shown in Figure 15, three rising wall portions 8b are formed at approximately equal intervals, each with a trapezoidal cross section with an upper side of approximately 60 mm, a lower side of approximately 72 mm, and a height (see symbol R) of approximately 120 mm. The depth length of each of the three rising wall portions 8b is approximately 550 mm, which corresponds to the length of one side of the base end plate portion 8a. The total weight of the second joint member 8, including the base end plate portion 8a and the rising wall portions 8b, is approximately 162.9 kg, and SCW550 steel is used as an example of a welded structural cast steel product.

[0050] Next, in this embodiment 3, the anti-pullout member 9 is implemented as a plurality (six in the illustrated example) of metal rods having an equal rectangular cross-sectional shape that is approximately the same shape and size (square of approximately 45 x 45 mm) as the cross-section of the through holes 77c, 88c, and having an equal length (approximately 550 mm) that penetrates the through holes 77c, 88c in a skewer-like manner. That is, in Example 3, the length of the retaining member 6 is set to be approximately the same as or slightly shorter (for example, about 550 mm) than the lengths of the base end plate portion 7a of the first coupling part 7 and the base end plate portion 8a of the second coupling part 8, thereby achieving a structure that prevents large gravel from colliding (directly hitting) with the retaining member 9. In other words, the base end plate portion 7a of the first coupling part 7 and the base end plate portion 8a of the second coupling part 8 are set to a size that covers the retaining member 9 when viewed in the axial direction of the steel pipes 10, 20, and thereby serve as a protective plate that protects the retaining member 9 from gravel. Incidentally, the total weight of the six retaining members 9 according to the first embodiment is approximately 52 kg.

[0051] It should be noted that the numerical values ​​such as the size of the components of the steel pipe joint structure according to Example 3 described in the above paragraphs

[0048] to

[0050] are merely examples and can be increased or decreased as appropriate depending on the structural design.

[0052] Therefore, in the steel pipe joint structure of the steel slit dam according to Example 3, when steel pipes are joined together horizontally, vertically, or inclined as needed to construct a three-dimensional steel slit dam, a steel pipe 10 equipped with the first joint member 7 and a steel pipe 20 equipped with the second joint member 8 are opposed to each other, and alignment work is performed as needed, such as butting or sliding the uneven portion 77 of the first joint member 7 against the uneven portion 88 of the second joint member 8, until the uneven portion 77 and the uneven portion 88 mesh (overlap without gaps in the illustrated example), and fine adjustment work is performed so that the centers of the alternatingly arranged through holes 77c of the uneven portion 77 and the through holes 88c of the uneven portion 88 are approximately aligned to form a connected state. As a result, in Example 3, a total of six rectangular tubular through holes 77c, 88c with the same length (approximately 550 mm) are formed. Thereafter, the six anti-slip members 9 are passed through the six through holes, respectively, and positioned using a fall-off prevention member such as a split pin, if necessary, thereby firmly maintaining the meshing state between the concave-convex portion 77 of the first joint member 7 and the convex-convex portion 88 of the second joint member 8, thereby achieving a steel pipe joint structure for a steel slit dam using the first joint member 7 and the second joint member 8, which has high strength and rigidity.

[0053] In addition, the uneven portion 77 and the uneven portion 88 according to this Example 3 are implemented by forming the groove wall portions 77b, 88b in a tapered shape to achieve good engagement, as in Example 1, but are not limited to this and can also be implemented by forming them in linear shapes parallel to the axial direction of the steel pipe. In addition, measures such as rounding the corners of the retaining member 9 over its entire length can be taken as appropriate to make the insertion into the through holes 77c, 88c smoother.

[0054] Therefore, according to the steel pipe joint structure of the steel slit dam of Example 3, in addition to having the same effects as in Example 1 above, it can be implemented with a structure that protects the anti-slip member 9 that maintains the interlocking state between the first joint member 7 and the second joint member 8 from gravel, and therefore it is possible to prevent damage and destruction of the anti-slip member 9 (steel pipe joint), and it is possible to achieve the same effects as in Example 2 above (for details, see [Effects of the Invention] in paragraph

[0014] of the specification).

[0055] Although the embodiments have been described above based on the drawings, it should be noted that the present invention is not limited to the illustrated examples and includes the range of design modifications and application variations that would normally be made by a person skilled in the art, provided that they do not deviate from the technical concept of the present invention.

[0056] For example, in the above-mentioned Example 1, the longest anti-pullout member 3 is longer (approximately 570 mm) than the outer diameter (approximately 550 mm) of the disk-shaped base end plate portions 1a, 2a. However, as in the above-mentioned Examples 2 and 3, in order to set the size of the anti-pullout member 3 so that it covers the steel pipes 10, 20 when viewed from the axial direction, the longest length of the anti-pullout member 3 can be set to be approximately the same length as or slightly shorter than the base end plate portions 1a, 2a (for example, approximately 550 mm), thereby achieving a structure that prevents large gravels from colliding (hitting directly) with the anti-pullout member 3.

[0057] As described above, the steel pipe joint structure for a steel slit dam according to the present invention can be extended and joined as needed in any direction, including horizontal, vertical, and inclined directions, to construct a three-dimensional steel slit dam. However, as can be seen in Figure 3, it is preferable in terms of the strength and rigidity of the joints that the rising wall portion 1b of the first joint member 1 and the rising wall portion 1b of the second joint member 2 are positioned in a direction substantially perpendicular to the river flow direction F (see also Figures 9 and 15). Depending on the orientation of the retaining member 3, it may be possible to increase the diameter of the protruding portion on one side (for example, the right side in Figure 3) like a headed bolt, in order to further enhance the retaining effect.

[0058] Furthermore, the shapes of the interlocking portions R (rising wall portions 1b, 2b, etc.) in the present Examples 1 to 3 are implemented as a combination of an inverted trapezoidal shape and a trapezoidal shape, but are not limited to this and may be any combination that allows them to interlock (contact) with each other with almost no gap between them. Of course, the cross-sectional shape of the retaining member 3 (or 6 or 9) is not limited to a square. [Explanation of symbols]

[0059] 1 First joint member 1a Base plate 1a' Ring-shaped protrusion 1b Rising wall 11 Uneven part 11a Groove 11b Groove wall 11c through hole 2 Second joint member 2a Base plate 2a' Ring-shaped protrusion 2b Rising wall 22 Uneven part 22a Groove 22b Groove wall 22c through hole 3. Anti-slip member 4. First joint member 4a Base plate 4a' Ring-shaped protrusion 4b Rising wall 44 Uneven part 44a Concave groove 44b Groove wall 44c through hole 5 Second joint member 5a Base plate 5a' Ring-shaped protrusion 5b Rising wall 55 Uneven part 55a Groove 55b Groove wall 55c through hole 6. Retaining member 7 First joint member 7a Base plate 7a' Ring-shaped protrusion 7b Rising wall 77 Uneven part 77a Groove 77b Groove wall 77c through hole 8 Second joint member 8a Base plate 8a' Ring-shaped protrusion 8b Rising wall 88 Uneven part 88a groove 88b Groove wall 88c through hole 9. Anti-slip member 10 Steel pipe 20 Steel pipe R Interlocking part F. River flow direction

Claims

1. In the joint structure of the joint between steel pipes that make up a steel slit dam, a first coupling member having a concave-convex portion forming steps in the axial direction of the steel pipe is provided at an end of one of the steel pipes, and a second coupling member having a convex-concave portion that engages with the concave-convex portion of the first coupling member is provided at an end of the other steel pipe; The uneven portion of the first joint member has a plurality of parallel grooves extending in a direction perpendicular to the axial direction of the steel pipes to be joined, the grooves being formed in the width direction of the first joint member; The concave and convex portions of the second joint member are formed by a plurality of parallel grooves extending in a direction perpendicular to the axial direction of the steel pipes to be joined in the width direction of the second joint member. a plurality of through holes penetrating the groove wall portions of the plurality of parallel grooves formed in the first joint member and the second joint member, and the meshing portions between the concave-convex portions of the first joint member and the convex-concave portions of the second joint member are joined by passing a retaining member through the through holes in a skewer-like manner.

2. 2. The steel pipe joint structure of a steel slit dam according to claim 1, wherein the first joint member and the second joint member each comprise a disk-shaped or rectangular base end plate portion provided at the end of the corresponding steel pipe and sized to protrude outward from the steel pipe, and the groove wall portion rising from the base end plate portion.

3. 3. A steel pipe joint structure for a steel slit dam according to claim 1, wherein the groove wall portion is formed in a tapered shape that narrows in width in the rising direction.

4. 4. A steel pipe joint structure for a steel slit dam as described in claim 2 or 3, characterized in that the base end plate portion of the first joint member and the base end plate portion of the second joint member are each set to a size that covers the anti-slip member when viewed from the axial direction of the steel pipe.

5. A steel pipe joint structure according to any one of claims 1 to 4, Steel slit dam.

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