JP2022182205A - rotary press-in pile - Google Patents

Abstract

To provide a rotary press-in pile bearing a load of a structure and suppressing subsidence of a structure.SOLUTION: A rotary press-in pile 1 comprises: a pile body 2 extending along an axial direction; a cylindrical outer cylinder 3 disposed coaxially with the pile body 2 at a tip portion of the pile body 2; and a plate-like pile supporting plate 4 connecting an outer peripheral face of the tip portion of the pile body 2 and an inner peripheral face of the outer cylinder 3 and obliquely extending with respect to an axial direction. The rotary pile penetrate a ground while rotating and is embedded underground.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a rotary press-in pile used when constructing a structure on the ground or the like.

Generally, in the construction of a structure such as a house, if the structure cannot be supported by a shallow foundation, foundation piles are driven in until the tip reaches the support layer deep in the ground, and the structure is supported by the driven foundation piles. ing. A foundation pile supports a load (load due to a structure) mainly by the tip bearing force acting upward on the tip of the pile. Foundation piles can also be used as foundation piles for signboard foundation piles, street light foundation piles, wind power generation foundation piles, and the like (that is, structures include pile-like structures). As this foundation pile, for example, there is a rotary press-fit pile described in Patent Document 1.

In Patent Document 1, in a rotary press-fit pile having a pile support plate processed with a steel plate or the like in a spiral shape at the tip of the pile, it is in contact with the outer periphery of the pile support plate and is bent so as to match the outer peripheral shape. A rotary press-fit pile is disclosed in which a support plate outer peripheral steel plate is provided so as to protrude in both the upper and lower directions of the pile support plate.

Conventional rotary press-in piles are embedded in the ground by a rotary press-in method. The rotary press-in method is a construction method in which piles are erected by rotary press-in to the supporting ground without vibration, noise, and soil removal for the purpose of maximizing the end bearing capacity of the rotary press-in pile.

However, in conventional rotary press-in piles, it is necessary to increase the diameter of the spiral pile support plate in order to expect a large bearing capacity. There is a problem that the plate itself is bent and a predetermined supporting force cannot be obtained.

JP-A-2000-352047

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a rotary press-fit pile that can withstand the load of a structure and suppress the settlement of the structure.

The rotary press-fit pile of the present invention for solving the above problems comprises a pile body extending along the axial direction, an outer tube having a cylindrical shape arranged coaxially with the pile body at the tip of the pile body, and the pile body and a plate-shaped pile support plate that connects the outer peripheral surface of the tip of the outer cylinder and the inner peripheral surface of the outer cylinder and extends obliquely with respect to the axial direction, and penetrates into the ground while rotating. , which are embedded in the ground.

In the rotary press-fit pile of the present invention, the pile support plate extends with an inclination with respect to the axial direction, and can be penetrated and buried in the ground by a rotary press-in construction method. Further, deformation of the pile support plate is suppressed by forming the pile support plate so as to connect the outer peripheral surface of the pile body and the inner peripheral surface of the outer cylinder. As a result, even if the diameter of the pile support plate is increased, a large area of the pile support plate can receive the bearing force without bending deformation. That is, the rotary press-fit pile of the present invention can support a structure with a large end bearing force.

In the rotary press-fit pile of the present invention, the pile support plate has a rectangular belt shape, the longitudinal direction of which extends along the radial direction, and the tip end of the rotary press-fit pile in the rotation direction is the rear end side. It is preferably located on the tip side from the end of the.

In the rotary press-fit pile of the present invention, the support plate preferably has a plate-like shape extending spirally along the outer peripheral surface of the pile body.

1 is a side view showing the appearance of a rotary press-fit pile 1 of Embodiment 1. FIG. 2 is a bottom view showing the configuration of the rotary press-fit pile 1 of Embodiment 1. FIG. 1 is a partial cross-sectional view showing the configuration of a rotary press-fit pile 1 of Embodiment 1. FIG. Fig. 10 is a bottom view showing the appearance of a rotary press-fit pile 1 of Embodiment 2; Fig. 11 is a side view showing the appearance of a rotary press-fit pile 1 of Embodiment 3; FIG. 11 is a partial cross-sectional view showing the configuration of a rotary press-fit pile 1 of Embodiment 3; FIG. 11 is a side view showing the appearance of a rotary press-fit pile 1 of Embodiment 4; It is a bottom view which shows the 1st structure of the rotary press-fit pile 1 of the deformation|transformation 1. FIG. It is a side view which shows the 1st structure of the rotary press-fit pile 1 of the modification 1. FIG. FIG. 5 is a partial cross-sectional view showing a second configuration of the rotary press-fit pile 1 of Modified Mode 1;

Hereinafter, the present invention will be specifically described using embodiments. In addition, each following embodiment is one form which implements this invention concretely, and does not limit this invention only to these forms. That is, the configuration of each form may be appropriately combined. Moreover, the same configuration and materials as those of conventional rotary press-fit piles can be used for configurations and materials that are not particularly mentioned in the embodiments. In each of the following embodiments, members having similar functions are given the same reference numerals.

In each of the following embodiments, directions such as a tip end direction, a base end direction, a circumferential direction, and a radial direction indicate directions in the pile body 2 of the rotary press-fit pile 1 unless otherwise specified. For example, the tip direction indicates the direction toward the end portion of the rotary press-fit pile 1 that is penetrated into the ground (for example, indicates the downward direction in FIG. 1). The proximal direction indicates the direction away from the distal end (eg, indicates the upward direction in FIG. 1).

[Embodiment 1]
A rotary press-fit pile 1 of this embodiment integrally has a pile main body 2, an outer tube 3, a pile support plate 4, and an outer tube support plate 5. The configuration of the rotary press-fit pile 1 of this embodiment is specifically shown in FIGS. 1 to 3. FIG. FIG. 1 is a side view (viewed from radially outward) showing the appearance of a rotary press-fit pile 1. FIG. FIG. 2 is a bottom view of the rotary press-fit pile 1 (viewed from the tip side). FIG. 3 is a partial cross-sectional view showing the configuration of the rotary press-fit pile 1. As shown in FIG.

The pile main body 2 is a member extending along the axial direction. The pile main body 2 is made of a pipe-shaped (hollow) or column-shaped (solid) member. The pile body 2 is not limited in its outer peripheral shape (outer peripheral shape on a plane perpendicular to the axial direction). The pile main body 2 of this embodiment consists of a hollow steel cylindrical pipe with a closed end.

The outer cylinder 3 is a member having a tubular shape arranged coaxially with the pile main body 2 at the tip portion of the pile main body 2 . The outer tube 3 is a tubular member having an inner diameter larger than the outer diameter of the pile body 2 . The outer cylinder 3 of this embodiment is made of a hollow steel cylindrical pipe. The length of the gap between the inner peripheral surface of the outer cylinder 3 and the outer peripheral surface of the pile body 2 is not limited. The longer the interval, the larger the contact area with the support layer, and the greater the bearing capacity of the rotary press-fit pile 1 . The distance between the inner peripheral surface of the outer cylinder 3 and the outer peripheral surface of the pile body 2 is preferably larger than the outer diameter of the pile body 2 .

The axial length of the outer cylinder 3 is not limited. Any length is sufficient as long as the pile support plate 4 and the outer tube support plate 5 can be provided.
The outer cylinder 3 is arranged at a position where the end face on the tip end side is slightly displaced toward the base end side from the end face on the tip end side of the pile body 2 . That is, the tip end face of the pile body 2 protrudes from the tip end face of the outer cylinder 3 .

The pile support plate 4 connects the outer peripheral surface of the tip portion of the pile body 2 and the inner peripheral surface of the outer cylinder 3 . The pile support plate 4 is a plate-shaped member extending obliquely with respect to the axial direction. The pile support plate 4 has a belt-like shape with a constant width. The pile support plate 4 is arranged such that its belt-like longitudinal direction extends along the radial direction. One end 40 in the width direction of the strip is located on the tip side from the other end 41 . That is, the strip-shaped pile support plate 4 is inclined in its width direction with respect to a plane perpendicular to the axial direction. One end 40 in the width direction of the strip-shaped pile support plate 4 is positioned on the traveling direction side in the rotation direction when the rotary press-fit pile 1 is rotated so as to penetrate into the ground (rotation direction in FIG. 2). at the end.

As shown in FIG. 3 , the pile support plate 4 is provided with one end 40 protruding from the tip end of the pile body 2 . At this time, the protrusion amount is not limited.
In this embodiment, two pile support plates 4 are provided at symmetrical positions in the circumferential direction around the pile body 2 .

The outer tube support plate 5 is a plate-like member that connects the outer peripheral surface of the pile body 2 and the inner peripheral surface of the outer tube 3 at a position closer to the base end side than the pile support plate 4 . The outer cylinder support plate 5 is provided in a state extending along the radial direction. The outer cylinder support plate 5 of the present embodiment is a belt-like (rod-like) member having a square cross section (rectangular cross section) provided in the vicinity of the proximal end of the outer cylinder 3 . That is, it is a strip-shaped member having a constant thickness and width. The outer cylinder support plate 5 of this embodiment is provided in a state in which the longitudinal direction of the rectangular cross section is along the axial direction. In this embodiment, four outer cylinder support plates 5 are provided at symmetrical positions in the circumferential direction around the pile main body 2 .

In addition, although the outer cylinder support plate 5 of this embodiment has a strip plate shape with a constant width, it is not limited to this shape. For example, a shape in which the cross-sectional area of a rectangular cross section changes depending on the position in the radial direction, specifically, the area of the connection portion with the outer peripheral surface of the pile body 2 is the area of the connection portion with the inner peripheral surface of the outer cylinder 3 It may have a shape larger than

(How to use this form)
The rotary press-fit pile 1 of this embodiment can be press-fit into the ground using a conventional construction method. For example, it can be pressed into the ground (ground with a soft ground surface) as follows.

First, the rotary press-fit pile 1 of this embodiment is hung by a crane and set in the excavated ground.
Next, the base end portion (upper end portion of the pile body 2) of the rotary press-in pile 1 set in the excavated ground is exposed to the outside, and the ground is backfilled.

Then, an upper pile is attached to the upper end of the rotary press-fit pile 1 by welding. After that, attach the auger motor to the upper end of the upper pile. The rotary press-in pile 1 and the upper pile are lowered into the ground while rotating the auger motor and rotating the rotary press-in pile 1 in the ground by its rotational force. Here, the rotation of the auger motor rotates the pile body 2 (rotary press-fit pile 1) clockwise. When the rotary press-in pile 1 rotates, one end 40 of the pile support plate 4 digs into the ground, guides the soft ground (such as earth and sand) on the lower side of the rotary press-in pile 1 upward, and rotates the press-in pile. The pile 1 penetrates (presses) into the ground.

Then, when the tip of the rotary press-fit pile 1 reaches a relatively hard ground layer with bearing strength, the rotation of the auger motor reaches a predetermined torque value. When this predetermined torque value is reached, construction by rotation of the rotary press-in pile 1 is completed. At this time, the tip of the rotary press-in pile 1 (particularly, the surface of the pile support plate 4 on the tip side) is buried in the ground in contact with the relatively hard ground layer (the relatively hard ground layer pushes the rotary press-in pile 1 state to support). In other words, the front surface of the pile support plate 4, which is inclined with respect to the axial direction, is in contact with a relatively hard ground layer over a wide area.
After that, a structure is built on the base end (upper end) of the rotary press-fit pile 1 .

(Effect of this form)
The rotary press-fit pile 1 of this embodiment includes a pile body 2 extending along the axial direction, an outer tube 3 having a tubular shape coaxial with the pile body 2 at the tip of the pile body 2, and a tip of the pile body 2. and a plate-like pile support plate 4 that connects the outer peripheral surface of the outer cylinder 3 and the inner peripheral surface of the outer cylinder 3 and extends obliquely with respect to the axial direction.

According to this configuration, in the rotary press-fit pile 1 of this embodiment, a decrease in bearing capacity due to deformation of the pile support plate 4 is suppressed. Specifically, the rotary press-fit pile 1 of this embodiment is provided in a state where the pile support plate 4 connects the outer peripheral surface of the pile body 2 and the inner peripheral surface of the outer cylinder 3, and the rotary press-fit pile 1 is rotated. Even if the pile support plate 4 tries to deform such as bending when it is press-fitted, the deformation is suppressed. As a result, the rotary press-fit pile 1 of this embodiment can contact a relatively hard ground layer without deformation of the pile support plate 4, and a desired bearing capacity can be obtained.

In addition, in the rotary press-fit pile 1 of this embodiment, deformation such as bending of the pile support plate 4 is suppressed, and the area of the pile support plate 4 (area in contact with the relatively hard ground layer) is increased. As a result, even if a larger load is applied to the rotary press-in pile 1, the load can be supported by a relatively hard ground layer.

In the rotary press-in pile 1 of this embodiment, the pile support plate 4 has a rectangular strip shape, the longitudinal direction of which extends along the radial direction, and the tip end of the rotary press-in pile 1 in the rotation direction ( One end 40 of the pile support plate 4) is located on the front end side of the rear end (the other end 41 of the pile support plate 4). According to this configuration, when the rotary press-in pile 1 rotates, one end 40 of the pile support plate 4 bites into the ground, and guides the ground (earth and sand, etc.) below the rotary press-in pile 1 upward. be able to.

In the rotary press-fit pile 1 of this embodiment, the end of the pile support plate 4 on the tip side in the rotation direction (one end 40 of the pile support plate 4 ) protrudes from the tip of the outer cylinder 3 . According to this configuration, when the rotary press-fit pile 1 is press-fitted while rotating, the rotary press-fit pile 1 is press-fit into the ground (the ground having a soft ground surface).

[Embodiment 2]
The rotary press-in pile 1 of this embodiment is the same as the rotary press-in pile 1 of the first embodiment except that the number of pile support plates 4 is different.

The rotary press-fit pile 1 of this embodiment has four pile support plates 4 as shown in the bottom view of FIG. The pile support plate 4 in this embodiment has a substantially fan-like shape when viewed from above. One end 40 of the pile support plate 4 in the substantially fan-shaped circumferential direction is located on the tip side from the other end 41 . That is, both the bottom surface (the surface facing the distal end side) and the upper surface (the surface facing the base end side) of the pile support plate 4 are provided in a state inclined with respect to the axial direction. One end portion 40 of the substantially fan-shaped pile support plate 4 is the end portion located on the traveling direction side in the rotation direction when the rotary press-in pile 1 is rotated so as to penetrate into the ground.

In this embodiment, four pile support plates 4 are provided at symmetrical positions in the circumferential direction around the pile body 2 . In this embodiment, as shown in FIG. 4, when the rotary press-fit pile 1 is viewed from the tip side, the space between the outer peripheral surface of the pile body 2 and the inner peripheral surface of the outer cylinder 3 is one of the piles. The supporting plate 4 prevents seeing through.

In this embodiment, the four pile support plates 4 are provided at positions that do not overlap, but two pile support plates 4 that are adjacent in the circumferential direction may be provided at positions that overlap in the circumferential direction. . Specifically, one end 40 of the pile support plate 4 may be provided so as to be located on the tip side of the other end 41 of another adjacent pile support plate 4 .

(Effect of this form)
The rotary press-in pile 1 of this embodiment has the same configuration as the rotary press-in pile 1 of the first embodiment except that the number of pile support plates 4 is different, and exhibits the same effects as the first embodiment.

The rotary press-fit pile 1 of this embodiment has a configuration in which there is no axially penetrating space due to the four pile support plates 4 . According to this configuration, in the rotary press-fit pile 1 of this embodiment, the pile support plate 4 comes into contact with the relatively hard ground layer over the entire inner surface of the outer cylinder 3, and a greater bearing capacity can be obtained.

[Embodiment 3]
The rotary press-fit pile 1 of this embodiment integrally has a pile body 2, an outer tube 3, and a pile support plate 6, as shown in FIGS. FIG. 5 is a side view showing the appearance of the rotary press-fit pile 1. FIG. FIG. 6 is a partial cross-sectional view showing the configuration of the rotary press-fit pile 1. As shown in FIG.
In this embodiment, the pile main body 2 and the outer tube 3 have the same configuration as in the first embodiment.

The pile support plate 6 connects the outer peripheral surface of the pile body 2 and the inner peripheral surface of the outer cylinder 3 . The pile support plate 6 is provided so that a plate-like member having a predetermined width (the distance between the outer peripheral surface of the tip of the pile main body 2 and the inner peripheral surface of the outer cylinder 3) forms a spiral shape. The pile support plate 6 of this embodiment has a helical shape that encircles the outer periphery of the pile body 2 approximately twice. The pile support plate 6 is formed in a state in which an end portion 60 on the tip side faces the same direction as the inclination direction of the pile support plate 4 of the first embodiment.

As in the first embodiment, the pile support plate 6 is provided such that the tip end portion 60 protrudes from the tip end portion of the pile body 2 . In this case, the protrusion amount is not limited.

(Effect of this form)
The rotary press-in pile 1 of this embodiment has the same configuration as the rotary press-in pile 1 of the first embodiment except that the pile support plate 6 has a different shape, and exhibits the same effects as the first embodiment.

In the rotary press-in pile 1 of this embodiment, when the rotary press-in pile 1 rotates, the end 60 on the tip side of the spiral pile support plate 6 penetrates the ground so as to bite into the ground below the rotary press-in pile 1. Constructing earth and sand are continuously guided to the upper side of the pile support plate 6. - 特許庁That is, the rotary press-fit pile 1 of this embodiment can penetrate into the ground while continuously drilling holes.

The rotary press-fit pile 1 of this embodiment has a configuration in which there is no axially penetrating space due to the spiral pile support plate 6 . According to this configuration, the rotary press-fit pile 1 of this embodiment can contact the relatively hard ground layer over the entire inner surface of the outer cylinder 3 without the pile support plate 4 deforming, thereby obtaining a greater bearing capacity. can be done.

[Embodiment 4]
The rotary press-in pile 1 of this embodiment is the same as the rotary press-in pile 1 of the third embodiment, except that the shape of the pile support plate 6 (specifically, the length in the axial direction) is different.

In the rotary press-fit pile 1 of this embodiment, as shown in the partial cross-sectional view of FIG. It protrudes from the end. That is, the tip end portion 60 of the pile support plate 6 protrudes from the tip end portion of the outer cylinder 3 . A proximal end portion 61 of the pile support plate 6 protrudes from a proximal end portion of the outer cylinder 3 .

(Effect of this form)
The rotary press-in pile 1 of this embodiment has the same configuration as the rotary press-in pile 1 of the third embodiment except that the pile support plate 6 has a different shape, and exhibits the same effects as the third embodiment.

In the rotary press-fit pile 1 of this embodiment, the proximal end 61 of the pile support plate 6 protrudes from the proximal end of the outer cylinder 3, and constitutes the ground on the lower side of the rotary press-fit pile 1. Earth and sand are continuously guided and discharged to the upper side of the outer cylinder 3 . That is, clogging of earth and sand inside the outer cylinder 3 is suppressed, and the rotary press-fit pile 1 can be penetrated into the ground more easily and reliably.

[Modified form 1]
In each of the above-described forms, the outer peripheral surface of the outer cylinder 3 may be provided with outer peripheral feathers 7 (70, 71) protruding radially outward.

An example of this modification is a form in which the rotary press-fit pile 1 of the first embodiment is further provided with an outer peripheral feather 70 . As shown in the side view of FIG. 8 and the bottom view of FIG. 9, the peripheral blades 70 are provided in the shape of flat plates inclined with respect to the axial direction. This inclination is such that the forward side in the direction of rotation is located in the distal direction. The outer peripheral blade 70 is formed so that the pile support plate 4 of Embodiment 1 penetrates the outer cylinder 3 .

Another example of this modification is a form in which the rotary press-fit pile 1 of Embodiment 3 is further provided with outer peripheral feathers 71 . As shown in the partial cross-sectional view of FIG. 10, the outer peripheral blades 71 are provided so as to form a spiral shape along the outer peripheral surface of the outer cylinder 3 . The outer peripheral blades 71 are formed so that the pile support plate 6 of the third embodiment penetrates the outer cylinder 3 .

The amount of protrusion of the outer peripheral blades 7 (70, 71) from the outer peripheral surface of the outer cylinder 3 is not limited. It is preferably 50% or less of the radial length of the pile support plate 4 or the pile support plate 6 (that is, the distance between the outer peripheral surface of the pile main body 2 and the inner peripheral surface of the outer cylinder 3).

The outer peripheral blades 7 can continuously guide the ground (earth and sand, etc.) below the rotary press-in pile 1 upward on the outer circumference of the outer cylinder 3 when the rotary press-in pile 1 rotates. As a result, the frictional force received when the rotary press-fit pile 1 rotates and is press-fitted can be reduced.

[Modified form 2]
In each of the above-described forms, the outer cylinder 3 may have a through hole that penetrates the inside and the outside.

An example of this modification is a form in which a through hole is further opened in the rotary press-fit pile 1 of the first embodiment. The through-hole is provided on the base end side of the position where the pile support plate 4 of the outer cylinder 3 is formed.

The diameter of the opening of the through-hole is not limited. A circular shape is preferred. The opening diameter of the through-hole is also not limited, but the strength of the outer cylinder 3 decreases as the opening diameter increases, so it is preferable that the opening diameter is not excessively large.

The through-hole can discharge the ground (such as earth and sand) on the lower side of the rotary press-fit pile 1 guided inside the outer cylinder 3 to the outside of the outer cylinder 3 when the rotary press-fit pile 1 rotates. Damage to the outer cylinder support plate 5 by earth and sand, etc., and clogging of the inside of the outer cylinder 3 are suppressed.

1: rotary press-fit pile, 2: pile main body, 3: outer cylinder, 4, 6: pile support plate, 5: outer cylinder support plate, 7, 70, 71: outer peripheral wings.

The rotary press-fit pile of the present invention for solving the above problems comprises a pile body extending along the axial direction, an outer tube having a cylindrical shape arranged coaxially with the pile body at the tip of the pile body, and the pile body A plate-like pile support plate that connects the outer peripheral surface of the tip of the and the inner peripheral surface of the outer cylinder and extends obliquely with respect to the axial direction, the outer peripheral surface of the pile body and the outer cylinder and an outer cylinder support plate extending along the radial direction of the pile body at a position spaced apart from the rear end of the pile support plate, penetrating into the ground while rotating. and embedded in the ground.

1 is a side view showing the appearance of a rotary press-fit pile 1 of Embodiment 1. FIG. 2 is a bottom view showing the configuration of the rotary press-fit pile 1 of Embodiment 1. FIG. 1 is a partial cross-sectional view showing the configuration of a rotary press-fit pile 1 of Embodiment 1. FIG. Fig. 10 is a bottom view showing the appearance of a rotary press-fit pile 1 of Embodiment 2; Fig. 11 is a side view showing the appearance of a rotary press-fit pile 1 of Embodiment 3; FIG. 11 is a partial cross-sectional view showing the configuration of a rotary press-fit pile 1 of Embodiment 3; It is a side view which shows the external appearance of the rotary press-fit pile 1 of a reference form . It is a bottom view which shows the 1st structure of the rotary press-fit pile 1 of the deformation|transformation 1. FIG. It is a side view which shows the 1st structure of the rotary press-fit pile 1 of the modification 1. FIG. FIG. 5 is a partial cross-sectional view showing a second configuration of the rotary press-fit pile 1 of Modified Mode 1;

[ Reference form ]
The rotary press-in pile 1 of this embodiment is the same as the rotary press-in pile 1 of the third embodiment, except that the shape of the pile support plate 6 (specifically, the length in the axial direction) is different.

Claims (7)

a pile body extending along the axial direction;
an outer cylinder having a cylindrical shape arranged coaxially with the pile body at the tip of the pile body;
a plate-like pile support plate that connects the outer peripheral surface of the tip portion of the pile body and the inner peripheral surface of the outer cylinder and extends obliquely with respect to the axial direction;
A rotary press-fit pile characterized by penetrating into the ground while rotating and being buried in the ground. The pile support plate has a rectangular band shape, the longitudinal direction of which extends along the radial direction, and the end on the tip side in the rotation direction of the rotary press-fit pile is closer to the tip than the end on the rear end side. 2. The rotary press-in pile of claim 1, located at . 3. The rotary press-fit pile according to claim 2, wherein the end of the pile support plate on the tip side in the rotation direction protrudes from the tip of the outer cylinder. The rotary press-fit pile according to any one of claims 2 and 3, wherein a plurality of said pile support plates are arranged along the circumferential direction. 2. The rotary press-fit pile according to claim 1, wherein the pile support plate has a plate shape extending spirally along the outer peripheral surface of the pile body. 6. The rotary press-fit pile according to claim 5, wherein the pile support plate has a tip-side end projecting from the tip of the outer cylinder. The rotary press-fit pile according to any one of claims 5 and 6, wherein the pile support plate has a rear end portion protruding from the rear end of the outer cylinder.

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