JP2004052498A - Joint forming method for concrete pile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To form a welding section having a groove width and a throat thickness having proper sizes to the joining section of a concrete pile, to which a welding junction is not prearranged, and to form an excellent welding junction section between the upper and lower concrete piles. <P>SOLUTION: A ring-shaped spacing plate 20 having an outside diameter smaller than end plates 13a and 13b is held between the end plates of upper and lower piles, and openings formed of the upper-lower end plates 13a and 13b and the spacing plate 20 are welded at a site. The spacing plate 20 in which thin straight steel strip having a cross section having different left-right thicknesses is bent in a circular shape by a rolling and formed in a ring shape having a uniform thickness is used as the spacing plate 20. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for forming a joint of a concrete pile in which end plates of a concrete pile having no groove are welded to each other.
[0002]
[Prior art]
When joining concrete piles up and down, a welding groove is usually formed in advance on the peripheral edge of the end plate, and welding is performed within this groove.
[0003]
By the way, there are piles that are joined by using another joining method without planning welding, and in such a concrete pile, a weld groove is not formed on an end plate. Nevertheless, there are cases in which a pile without such a groove must be welded and joined. In such a case, a welding groove is formed by gouging or the like. It is extremely difficult to machine the groove accurately. In addition, since the end plate is not scheduled to be grooved, if the groove is processed, the end plate thickness at that portion may be insufficient.
[0004]
[Problems to be solved by the invention]
The present invention is a technique applied in such a case, and forms a welded portion (groove) having a groove width and a throat thickness of appropriate dimensions at a joint portion of a concrete pile not scheduled to be welded. It is an object of the present invention to provide a technique for welding an excellent joint between concrete upper and lower piles.
[0005]
[Means for Solving the Problems]
The present invention has been made in order to solve the above-mentioned problem, and in welding a pile having no welding groove formed on an end plate, a ring-shaped space having an outer diameter smaller than the outer diameter of the end plate. A method of forming a joint for a concrete pile, comprising sandwiching a plate between end plates of upper and lower piles and performing on-site welding in a gap formed by upper and lower end plates and an outer periphery of a spacing plate.
[0006]
The spacing plate can be easily and easily substantially formed by using a spacing plate formed by bending a thin straight steel strip having a different thickness on the left and right sides of a cross section into a circular shape with a uniform thickness. This is preferable because a spacer having a uniform thickness can be obtained.
[0007]
Further, the present invention can be suitably applied to a case where the pile not forming the welding groove is only one of the upper and lower piles to be joined.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0009]
FIG. 1 is an explanatory view showing a welded joint between a concrete upper pile 10a and a concrete lower pile 10b of the embodiment. The right half of FIG. 1 is an outline view of the pile, and the left half is a vertical step view. The upper and lower piles 10a and 10b are provided with end plates 13a and 13b respectively having cover plates 12a and 12b attached to ends of skeletons 11a and 11b made of reinforced concrete or prestressed concrete.
[0010]
The present invention relates to a technique of welding and joining the end plates 13a and 13b which are not scheduled to be joined by welding. For example, the end plate of the non-welded joint pile, which has already been proposed and popular by the applicants, is not machined for welding. However, even in such piles, welding may be performed. For example, there is a case where pile driving is performed under conditions where the increase in the outer diameter of the pile is restricted.
[0011]
In the present invention, when a pile having no welding groove formed thereon is welded to such an end plate, a ring-shaped spacing plate 20 is sandwiched between the end plates 13a and 13b of the upper and lower piles 10a and 10b, and the upper and lower end plates are formed. Field welding is performed on a gap formed between 13a, 13b and the outer periphery of the spacing plate 20. FIG. 2 shows an enlarged view of this welding gap. The ring-shaped spacing plate 20 has a thickness that forms the welding groove 31 and has an outer diameter smaller than the outer diameters of the end plates 13a and 13b. The thickness of the weld throat 32 formed by the slab forms a suitable weld groove depth.
[0012]
When the spacing plate 20 is sandwiched between the end plates 13a and 13b, as shown in FIG. 3, a required number of through holes 21 are provided in the spacing plate 20, and the spacing plate 20 is placed on the end plate and the through holes 21 are formed. It is preferable to connect by plug welding which applies welding to the fins. Further, as another fixing means, as shown in FIG. 4, a fillet weld 22 may be applied to the inner and outer diameter portions of the spacing plate 20 and fixed on the end plate 13b.
[0013]
FIG. 5 is a cross-sectional view for explaining the manufacture of the spacing plate 20. The spacing plate 20 is formed by rolling a thin straight steel strip having a cross section having different thicknesses on the left and right as shown in FIG. In this way, the spacing plate 20 can be easily and inexpensively manufactured by bending and rolling without requiring a large-area steel plate for cutting the same or machining finish. The cross-sectional dimensions of the steel strip in a straight state are such that one thickness 23 is large, the other thickness 24 is small, and a required width 25 is provided. This strip is manufactured by bending into a ring shape with the thicker portion having a thickness 23 as an outer diameter and the thickness 24 as an inner diameter. For example, in the spacing plate 20 used for connecting a pile having an outer diameter of 600 mm, the dimension of the thicker thickness 23: 10.1 mm
Dimension of thinner thickness 24: 7.9mm
Dimension of required width 25: 79.5 mm
Outer diameter of molded ring: 576mm
Then, the spacing plate 20 having a uniform thickness can be easily obtained by rolling.
[0014]
FIG. 6 shows the shape of the groove at the welded joint between the end plates 13a and 13b of the conventional concrete pile. The groove dimensions are as follows: the groove opening 34 is 8.8 mm, the groove depth 35 is 12 mm, the roundness 36 of the groove bottom is 2 mmR, and the inclination angle 37 of the groove side wall is 20 to 30 °. The present invention can be suitably applied even if one of the end plates of the upper and lower piles to be welded and joined has a groove already formed as shown in FIG.
[0015]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, the weld part (groove) provided with the groove width and throat thickness of a suitable dimension is formed in the joint part of the concrete pile which does not plan welding joint, and the excellent weld joint between concrete upper and lower piles It becomes possible to form a part.
[Brief description of the drawings]
FIG. 1 is an explanatory view showing a joint portion of a pile according to an embodiment.
FIG. 2 is an explanatory view showing a groove shape of an embodiment.
FIG. 3 is an explanatory view showing attachment of a spacing plate.
FIG. 4 is an explanatory view showing attachment of a spacing plate.
FIG. 5 is a sectional view showing dimensions of a spacing plate.
FIG. 6 is a shape view of a conventional groove.
[Explanation of symbols]
10a, 10b Concrete upper and lower piles 11a, 11b Frames 12a, 12b Cover plates 13a, 13b End plates 20 Interval plates 21 Through holes 22 Fillet welds 23 One thickness 24 Other thickness 25 Required width 30 Welding 31 Opening First opening 32 Throat thickness

Claims (3)

When welding a pile that does not have a weld groove on the end plate, sandwich a ring-shaped spacing plate with an outer diameter smaller than the outer diameter of the end plate between the end plates of the upper and lower piles, and A joint forming method for a concrete pile, wherein a gap formed between an outer periphery of a spacing plate and an outer periphery of the spacing plate is welded. 2. The concrete pile according to claim 1, wherein the spacing plate is a ring-shaped spacing plate formed by bending a thin straight steel strip having different thicknesses on right and left sides of a cross section into a circular shape with a uniform thickness. 3. Joint formation method. The method for forming a joint for a concrete pile according to claim 1, wherein the pile having no weld groove is only one of the upper and lower piles to be joined.

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