JP2003064671A - Steel pipe pile with end blade - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steel pipe pile with an end blade, whose end has the spiral blade, and which enables the upward smooth discharge of gravel and boulder, dug up in excavation into ground. SOLUTION: In this steel pipe pile 1 with the end blade, the spiral blade 2 is fixedly mounted on an outer periphery of the end of the steel pipe pile 1 in such a manner that approximately one turn of the spiral blade 2 is wound on the outer periphery thereof; and a notched part 3 having a prescribed width W is drilled in a part of the spiral blade 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steel pipe pile having a spiral blade at its tip, and in particular, a notch is provided in a part of the spiral blade to remove gravel or boulders in the ground when the steel pipe pile is dug. The present invention relates to a steel pipe pile with a tip blade that can be removed from the cutout portion.

[0002]

2. Description of the Related Art As a conventional steel pipe pile constructed by attaching a spiral blade of this kind to the tip, for example, Japanese Patent Publication No. 5-42.
524, JP-A-8-209690, JP-A-9-324419, JP-A-9-324420, and the techniques shown in FIGS. 4 and 5 are known.

These prior arts have a structure in which a spiral blade 52 made of a steel plate is integrally attached to the outer peripheral surface of the tip end portion of a steel pipe pile 51, as generally illustrated in FIGS. 4 and 5. The spiral blade 52 is formed to have a size such that the spiral blade 52 is at least completely wound around the outer peripheral surface of the tip end portion of the steel pipe pile 51.

The spiral blades 52 provided at the tip of the above-mentioned steel pipe pile 51 have the function of rotating and excavating the steel pipe pile 51, and imparting a large supporting force to the steel pipe pile 51 deeply buried in the ground. It was working. Reference numeral 53 in FIG. 4 is a shake preventing device for preventing the steel pipe pile 51 from shaking. Also, G indicates the ground.

Further, in order to make the excavation of the steel pipe pile 51 more effective, as shown in FIG. 4, a bit piece 54 acting as a plurality of excavating blades or excavating claws at the most distal end of the steel pipe pile 51, 5
No. 5 was projected, and the bit pieces 54 and 55 were devised so that excavation into the ground could be performed more smoothly.

Further, as disclosed in the above-mentioned Japanese Patent Publication No. 5-42524, the outer peripheral portion of the tip of the spiral blade is cut out in a three-month shape so that the spiral blade can be smoothly dug into the ground. Technology was also being developed.

[0007]

However, in the above-mentioned conventional steel pipe pile with a tip blade, the spiral blade having a length of at least one turn is attached to the outer periphery of the tip portion of the steel pipe pile. When the steel pipe pile is gradually dug into the ground,
Due to the gravel and cobblestones buried in the ground, various problems as described below occurred.

That is, when the steel pipe pile is dug into the ground, the gravel and cobblestones buried in the ground are excavated by the spiral blades, and these gravel and cobblestones are almost all around the circumference of the steel pipe pile. Since the spiral blade is attached across
When excavating a steel pipe pile, it was not possible to remove these gravel and boulders in the upward direction of the steel pipe pile.

Therefore, when the steel pipe pile is continuously excavated, more and more gravel and cobblestones are accumulated on the lower surface side of the spiral blade, making it difficult to excavate the steel pipe pile, and when the excavation is continued forcibly. Since the gravel and the cobblestone are strongly contacted with the spiral blade, there is a problem that the spiral blade is deformed or damaged.

Therefore, when burying a steel pipe pile in a place where many gravel and cobblestones are conventionally buried, preparation work for removing the gravel and cobblestone in the ground at that place is required in advance, and There was a problem of poor construction efficiency.

The steel pipe pile with tip blades according to the present invention is a completely new technology developed in view of the above-mentioned conventional problems, and in particular, a part of the spiral blade attached to the tip portion of the steel pipe pile has a predetermined shape. It provides a technology for steel pipe piles that are configured by providing notches with a width so that gravel and cobblestones can be easily removed upward from the notches of the spiral blades when excavating the steel pipe pile. is there.

[0012]

A steel pipe pile with tip blades according to the present invention is an invention which has fundamentally improved many of the problems of the prior art described above. The gist of the first invention is the outer periphery of the pile. In a steel pipe pile in which a spiral blade that can be wound almost along one end is attached to the tip portion, a tip blade having a notch of a predetermined width is provided in a part of the spiral blade. It is a steel pipe pile.

In the steel pipe pile according to the above-mentioned first invention,
Since a part of the spiral blade attached to the tip of the steel pipe pile is provided with a notch of a specified width, when this steel pipe pile is dug into the ground, gravel and excavated by the spiral blade The cobblestone can be gradually discharged and removed from the notch of the spiral blade to be removed.

When the steel pipe pile according to the present invention is used,
Even when the excavation of the steel pipe pile is continued up to the final stage, gravel and cobbles do not accumulate on the lower surface side of the spiral blade to prevent the excavation of the steel pipe pile. Therefore, there is no fear of deforming or damaging the spiral blade, and further preparatory work for removing the gravel and cobblestone in the ground in advance can be eliminated.

The gist of the second invention of the steel pipe pile with a tip blade according to the present invention is that a blade piece of a predetermined width is attached to a predetermined position on the outer periphery of the upper steel pipe pile corresponding to the cutout portion of the spiral blade. Is a steel pipe pile with tip blades according to the first invention.

In the above-mentioned second invention, since the blade piece having the predetermined width is attached to the predetermined position on the outer periphery of the upper steel pipe pile corresponding to the cutout portion of the spiral blade, the cutout is formed by the blade piece. It is possible to compensate for the decrease in the bearing capacity of the steel pipe pile due to the section.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the steel pipe pile with tip vanes according to the present invention will be described in detail with reference to the drawings. FIG. Two
1 is a plan view of blades of a steel pipe pile with tip blades of FIG. 1, and FIG. 3 is an enlarged explanatory view of a main part of a steel pipe pile with tip blades of another example.

An embodiment of the steel pipe pile according to the present invention will be described in detail with reference to FIGS. 1 and 2. Reference numeral 1 is a steel pipe pile, and a spiral blade 2 is provided on the outer periphery of the tip end of the steel pipe pile 1. It is attached so that the outer circumference is wound almost once.

Further, the spiral blade 2 is provided with a notch 3 having a predetermined width. The notch 3 is a hole that acts to discharge upwardly the gravel and cobblestone dug up by the spiral blade 2. The shape of the notch 3 is not particularly limited, but it is more effective to form it into a fan shape as shown in the figure.

Regarding the width W of the cutout portion 3, the present inventor has also conducted various experiments over the years, and as a result, the width of the spiral blade 2 becomes about ⅛ of the length of the spiral blade 2. When a part of 2 is cut off, the gravel and cobblestone in the ground dug up by the spiral blade 2 of the steel pipe pile 1 are smoothly discharged upward from the cutout portion 3, and the support of the steel pipe pile 1 by the spiral blade 2 is provided. It turned out that the strength did not drop so much.

Therefore, for example, the pile diameter of the steel pipe pile 1 is 267.
When the width W of the notch 3 is set to about 200 mm when the diameter of the spiral blade 2 is set to 4 mm and the diameter of the spiral blade 2 is set to 500 mm, the gravel or cobblestone excavated in the ground will be present between the notches 3. It passed and was found to be smoothly removed upwards.

The inventor of the present invention, since the supporting force of the steel pipe pile 1 is reduced to some extent when the spiral blade 2 is provided with the cutout portion 3 as described above, the means for preventing the reduction of the supporting force will be described. As a result of various studies, as shown in FIG. 3, the steel pipe pile 1 corresponding to the notch 3 was provided with a blade piece 4 having a predetermined width.
It has been invented that the mounting force can be compensated for when the notch 3 is provided, when it is mounted at a predetermined position above the.

Further, it has been found that the blade piece 4 can be used as it is as a cut-out piece obtained by cutting off a part of the spiral blade 2 to form the cutout portion 3. And
The mounting position of the blade piece 4 is determined by the cutout portion 3 of the spiral blade 2.
It was also clarified that when it was mounted about 200 mm above, it would not interfere with the gravel or cobblestone that passes through the notch 3 and is discharged upward.

In the figure, 5 and 6 are bit pieces projecting from the tip of the steel pipe pile 1, respectively, so that the steel pipe pile 1 can be dug into the ground more smoothly as in the conventional example described above. Is provided.

[0025]

In the steel pipe pile according to the present invention, since the spiral blade attached to the tip end of the steel pipe pile is provided with a cutout portion of a predetermined width, the steel pipe pile is underground. When it is dug forward, it has the effect that the gravel and cobblestone excavated by the spiral blade can be gradually discharged upward from the notch of the spiral blade and removed.

When the steel pipe pile according to the present invention is used,
Even when the excavation of the steel pipe pile is continued up to the final stage, gravel and cobbles do not accumulate on the lower surface side of the spiral blade to prevent the excavation of the steel pipe pile. Therefore, there is a great effect that there is no fear of deforming or damaging the spiral blade, and further that the preparatory work for removing the gravel and cobblestone in the ground beforehand is unnecessary.

Further, when a blade piece having a predetermined width is attached to a predetermined position on the outer circumference of the upper steel pipe pile corresponding to the cutout portion of the spiral blade, the support force of the steel pipe pile by the cutout portion is provided by this blade piece. Has the effect of being able to compensate for the decrease in

[Brief description of drawings]

FIG. 1 is an enlarged explanatory view of a main part of a steel pipe pile with a tip blade according to the present invention.

FIG. 2 is a plan view of blades of the steel pipe pile with a blade tip in FIG.

FIG. 3 is an enlarged explanatory view of a main part of a steel pipe pile with a tip blade of another example.

FIG. 4 is a perspective explanatory view of a conventional steel pipe pile with tip blades.

FIG. 5 is an explanatory view showing a state in which a conventional steel pipe pile with tip blades is buried in the ground.

[Explanation of symbols]

1… Steel pipe pile 2 ... spiral blade 3 ... Notch 4 ... feather pieces 5 ... Bit piece 6 ... Bit piece 51… Steel pipe pile 52 ... spiral blade 53 ... Anti-shake device 54 ... Bit piece 55 ... Bit piece W: width of notch G ... the ground

Claims (2)

[Claims] 1. A steel pipe pile in which a spiral blade that can be wound around the circumference of the pile is attached to a tip end portion of the pile, wherein a part of the spiral blade is provided with a notch having a predetermined width. A steel pipe pile with a tip blade that is characterized. 2. The steel pipe pile with tip blades according to claim 1, wherein a blade piece having a predetermined width is attached at a predetermined position on the outer circumference of the upper steel pipe pile corresponding to the cutout portion of the spiral blade.