JPH0643036U - Steel pipe pile - Google Patents

Abstract

(57) [Summary] [Purpose] To make it possible to economically and easily construct steel pipe piles with varying cross-sectional configurations. [Structure] A strip steel pipe 1 having a hollow rectangular cross section is spirally wound and welded together at the edges 1a, 1a of the strip steel plates joined together to form a double pipe A steel pipe pile. This steel pipe pile is
It can be automatically created by conventional spiral steel pipe manufacturing equipment. The section modulus of the double pipe A can be continuously changed by adjusting the distance between the pinch rolls in the apparatus.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a steel pipe pile using a double spiral steel pipe.

[0002]

[Prior art]

 In pile foundations, for example, the bending moment is largely applied to the pile heads, so in the case of steel pipe piles, the economic design is such that the cross-sectional structure of the pile is changed only at the part where the bending moment is large. In general, steel pipes with different plate thicknesses are welded to each other by welding, or steel pipes for piles are fitted with other steel pipes and then welded.

[0003]

[Problems to be solved by the device]

 However, as described above, not only is skill required to join the shells of steel pipes having different plate thicknesses, but also the number of processes for forming the groove for welding is increased in the production of steel pipe piles. In addition, the method of fitting and welding steel pipes also requires that a steel pipe with a special diameter for that purpose be manufactured with high precision, and that welding is as troublesome as in the case of joints.

The present invention solves the above-mentioned conventional problems and provides a steel pipe pile that does not require a welding process of a body joint after manufacturing a steel pipe and has a large drag resistance and is highly economical. Is.

[0005]

[Means for Solving the Problems]

 The structure of the present invention for achieving the above object will be described with reference to the drawings corresponding to the embodiments. In the steel pipe pile of claim 1, a strip steel plate 1 having a hollow rectangular cross section is wound in a spiral shape. It is characterized in that the joined edges 1a, 1a of the strip steel sheet 1 are rotated and continuously welded 2 to each other to form a double pipe A.

In the steel pipe pile of claim 2, the strip steel plate 1 having a hollow rectangular cross section is spirally wound, and the joined edges 1a, 1a of the strip steel plate 1 are continuous with each other. It is welded 2 to a double pipe A, and the thickness t from the inner surface to the outer surface of the double pipe A is continuously changed in the length direction of the double pipe A. It is what

[0007]

[Action]

 By winding a strip steel plate 1 having a hollow rectangular cross-section in a spiral shape and welding 2, a single pile can be formed without body welding.

[0008]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of the steel pipe pile of the present invention. As shown in FIG. 2, a strip steel plate 1 having a hollow cross-section is used, which is spirally wound and The outer edges and the inner edges of the joined strip steel plates 1a, 1a are continuously welded 2 and 2 to form a double pipe having a required length. Then, annular end plates 3 and 3 having a thickness t of the strip steel plate 1 are fixed to the upper and lower ends by welding.

The above double pipe is produced by, for example, a device as shown in FIG. That is, the strip steel plate 1 is continuously fed in the direction of the arrow a from the material feeding device (not shown) through the guide plates 4, 4 and the guide rolls 5, 5, 6, 6 and the traveling path is in the traveling route. The relay device 7, the pinch rolls 8 and 8 and the side guide rolls 9 and 9 are sequentially arranged. Then, the strip steel plate 1 that has passed through the side guide rolls 7, 7 is spirally wound by a conventionally known spiral steel pipe manufacturing apparatus. That is, the rollers 11 and 11 of the inner surface supporting frame 10 and the forming rollers 12 and 12 arranged on the outer surface are bent to have a predetermined diameter, and the strip steel plate 1 is spirally wound with the edges 1a and 1a being in contact with each other. Then, the inner welding torch 13 and the outer welding torch 14 continuously weld 2 the edges 1a, 1a contacting each other to form the double spiral steel pipe A. In addition, since the edge of the edge of the hollow rectangular strip steel plate 1 is usually formed in a slightly angled shape, the welding can be performed without the groove processing.

In the present invention, the section modulus can be changed by changing the thickness of the double pipe A, that is, the thickness t of the strip steel plate 1 in the length direction of the pile. Fig. 3 shows an example of this, and the pile is formed such that the thickness t of the strip steel plate 1 gradually decreases from the head end to the tip, and the section modulus of the pile changes continuously. . In order to form such a pile, the interval between the pair of upper and lower pinch rolls 8 may be continuously narrowed during the transfer of the strip steel plate 1. In this case, since the strip steel plate 1 is formed while widening, the angular difference between the transfer direction of the strip steel plate 1 and the transfer direction of the double pipe A after formation is also sequentially changed. It is necessary to change the transfer direction of the double pipe A in sequence.

In the embodiment described above, the strip steel plate 1 has a hollow rectangular shape, and therefore, as shown in FIG. 3, stepped portions are formed at the joined edge portions 1a, 1a. As shown in FIG. 4, by making the cross-sectional shape of the strip steel plate 1 into a ladder shape that becomes thinner from one side to the other side, it is possible to eliminate the step portion that occurs between the joining edge portions 1a and 1a. It In order to do so, as shown in FIG. 7, the pair of upper and lower pinch rolls 8 and 8 may be provided in an inclined manner instead of being parallel to each other.

In the present invention, as described above, the steel pipe pile is not limited to the one formed by the double pipe A, for example, as shown in FIG. It is also possible to use the double pipe A only for the above, use the normal single pipe B for the other parts, and connect the double pipe A and the single pipe B together. Since the length of steel pipe piles is limited due to transportation from the manufacturing site to the site, in the actual construction of the piles, the piles should be sunk to a deeper layer than the length of the steel pipe pile according to the present invention. In many cases, the steel pipe pile of the double pipe A of the present invention is used as the upper pile, and this is spliced to the lower pile of the steel pipe pile B of the normal single pipe to form a pile foundation. Will be done.

[0013]

As described above, according to the present invention, a strip steel plate having a hollow rectangular cross section is spirally wound, and the joined edges of the strip steel plates are welded together to form a steel pipe pile. Therefore, as in the case of conventional pile foundations, steel pipes with different plate thicknesses are welded together in the field or steel pipes with different diameters are welded together by welding to strengthen the parts such as pile heads where large bending moments act. Therefore, steel pipe piles with the required strength can be obtained economically without performing troublesome and skilled work.

Further, the steel pipe pile of the present invention can be easily manufactured by using a conventionally well-known spiral steel pipe manufacturing apparatus, and also a steel pipe pile having a continuously changing section modulus can be freely manufactured.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of a steel pipe pile of the present invention.

FIG. 2 is a sectional view of a strip steel plate used for the steel pipe pile.

FIG. 3 is a longitudinal sectional view showing another embodiment of the steel pipe pile of the present invention.

FIG. 4 is a partial vertical cross-sectional view showing another embodiment of the present invention.

FIG. 5 is a vertical sectional view showing still another embodiment of the present invention.

FIG. 6 is an explanatory view of a process for constructing a steel pipe pile of the present invention.

FIG. 7 is a diagram showing another example of pinch rolls in the forming process.

[Explanation of symbols]

 A Double pipe 1 Strip steel plate 1a Edge 2 Weld 3 End plate 8 Pinch roll 10 Inner surface support frame 11 Roller 12 Forming roller 13 Inner surface welding torch 14 Outer surface welding torch

Claims (2)

[Scope of utility model registration request] 1. A strip steel sheet having a hollow rectangular cross section is spirally wound, and the edges joined to each other are
A steel pipe pile characterized by being welded to each other continuously to form a double pipe. 2. A strip steel sheet having a hollow rectangular cross section is spirally wound, and the edges joined to each other are
While being continuously welded to each other to form a double pipe,
A steel pipe pile, characterized in that the thickness from the inner surface to the outer surface of the double pipe is continuously changed in the length direction of the double pipe.