JP2022019187A - Existing pile removal device and existing pile removal method - Google Patents

Abstract

To provide an existing pile removal device capable of suppressing the increase of the sediment pressure at the opposite side of a fixed blade when inserting a casing that has the fixed blade for cutting an existing pile into the underground.SOLUTION: A cylindrical casing 2 is inserted into the underground G while excavating and swinging so as to enclose an existing pile 10 buried in the underground G in an eccentric state. A fixed blade 5 for cutting the existing pile is fixed in a part of the inner peripheral surface 2a of the casing 2 in the circumferential direction C. The casing 2 includes a first region A1 in which multiple first through openings 21 are formed side by side in the circumferential direction C at the opposite side of fixed blade 5. When the casing 2 is swing-inserted, sediment pushed into the wedge-shaped part K1 between the peripheral surface of the existing pile 10 and the inner peripheral surface 2a of the casing 2 at the opposite side of the fixed blade 5 is discharged to the outside of the casing 2 via the first through-opening 21.SELECTED DRAWING: Figure 2

Description

The present invention relates to an existing pile removing device and an existing pile removing method.

A cylindrical casing with a cutter for excavation at the lower end is inserted into the ground while rotating the casing so as to enclose the existing pile buried in the ground, and after cutting the edge between the existing pile and the ground, the existing pile Is known as a method of removing the stake by pulling out or the like (see, for example, Patent Document 1).
In Patent Document 1, when a casing provided with a spiral screw on the outer peripheral surface is inserted into the ground, the casing is a portion where the screw is not provided in order to balance the rotational resistance due to the earth and sand inside and outside the casing. It has been proposed to allow the movement of earth and sand between the inside and outside of the casing through a hole drilled near the center in the height direction of the casing.

On the other hand, it is difficult to remove the entire existing pile at once. Therefore, the existing pile is cut at a position of a predetermined length from the upper end, and the existing pile is gradually removed from the upper portion.
For example, in Patent Document 2, existing piles are cut using fixed blades, which are a plurality of horizontal blades provided side by side in the circumferential direction on the inner peripheral surface slightly above the lower end of the casing. Specifically, first, the casing in a state of being eccentric with respect to the existing pile is inserted to a predetermined depth while swinging and rotating at a swing angle within a range in which the fixed blade does not interfere with the existing pile. At the stage of inserting to a predetermined depth, the casing is rotated all around to cut the existing pile with a fixed blade, and then the upper part of the cut portion of the existing pile is removed.

JP-A-2002-322646 Japanese Patent Application Laid-Open No. 2003-293369

However, when the casing in an eccentric state with respect to the existing pile is inserted into the ground while swinging, a wedge-shaped portion between the outer peripheral surface of the existing pile and the inner peripheral surface of the casing on the opposite side of the fixed blade. As the sediment is pushed into the casing, the sediment pressure increases on the opposite side of the fixed blade. Therefore, it becomes difficult for the casing to swing, and it becomes difficult to excavate and insert the casing.
An object of the present invention is an existing pile removing device and an existing pile removing method capable of suppressing an increase in sediment pressure on the opposite side of the fixed blade when a casing having a fixed blade for cutting an existing pile is inserted into the ground. Is to provide.

The invention according to claim 1 is an existing pile removing device (1) used for cutting and removing an existing pile (10) buried in the ground (G) to a predetermined length, wherein the existing pile is removed. A cylindrical casing (2) that is excavated and inserted into the ground so as to enclose the pile in an eccentric state, and a part of the casing in the circumferential direction (C) at a predetermined height from the lower end (2d) of the casing. A fixed blade (5) projecting and fixed to the inner peripheral surface (2a) of the casing is provided, and the casing is formed with a plurality of first through openings (21) arranged side by side in the circumferential direction on the opposite side of the fixed blade. Provided is an existing pile removing device including the first area (A1).

The alphanumerical characters in parentheses represent the corresponding components and the like in the embodiments described later, but this does not mean that the present invention should be limited to those embodiments, of course. The same shall apply hereinafter in this section.
As in claim 2, the height range (HA1) of the first region may be larger than the height range (H5) of the fixed blade in the height direction (H) of the casing (H5). HA1> H5).

As in claim 3, the height position of the first through opening in the first region may be offset with respect to the height position of the fixed blade with respect to the height direction of the casing.
As in claim 4, in the first region, a plurality of rows of first through openings having different height positions are formed, and the positions of the first through openings of adjacent rows in the height direction in the circumferential direction are staggered from each other. It may have been done.

As in claim 5, the casing may include a second region (A2) in which at least one second through opening (22) is formed below the fixed blade.
As in claim 6, the circumferential angle range (CA2) occupied by the second region is equal to (CA2 = C5) or equal to or greater than (CA2 = C5) the circumferential angle range (C5) occupied by the fixed blade (CA2 ≧ C5). ) May be used.

As in claim 7, the casing does not form a pair of openings extending over the entire height direction (H), each including a pair of intermediate regions (MA) between the first region and the second region. The region (A3) may be included.
As in claim 8, the circumferential angle range (CA3) occupied by each of the non-opening regions may be larger than the circumferential angle range (CA2) occupied by the second region (CA3>. CA2).

As in claim 9, the casing may include an opening non-forming region (A4) above the fixed blade.
As in claim 10, the fixed blade may be a single fixed blade provided on the inner peripheral surface of the casing at the position of the predetermined height.
The invention according to claim 11 is an existing pile removing method for removing an existing pile buried in the ground by using the existing pile removing device according to any one of claims 1 to 10. The process of inserting the pile into the ground to a predetermined depth while swinging the casing so as to enclose the pile in an eccentric state.
By rotating the casing inserted to the predetermined depth around the central axis of the casing, a cutting groove is formed on the outer peripheral surface of the existing pile by the fixed blade, and the existing pile is cut at the position of the cutting groove. Provided is an existing pile removing method including a step and a step of taking out an upper portion of a cut portion of the existing pile from the casing.

In the invention according to claim 1, the casing is swung around the central axis of the casing so that the cylindrical casing encloses the existing pile in an eccentric state, at a swing angle within a range in which the fixed blade does not interfere with the existing pile. , Drill and insert into the ground. At this time, a portion narrowed in a wedge shape in the circumferential direction is formed between the inner peripheral surface of the casing and the outer peripheral surface of the existing pile on the opposite side of the fixed blade. With the swing insertion of the casing, the earth and sand are pushed into the wedge-shaped narrowing portion on the opposite side of the fixed blade, and the pushed earth and sand is the first of the first region arranged on the opposite side of the fixed blade. It is discharged to the outer peripheral surface side of the casing through the through opening. Therefore, it is possible to suppress an increase in the sediment pressure in the casing on the opposite side of the fixed blade.

In the invention according to claim 2, the height range of the first region is made larger than the height range of the fixed blade in the height direction of the casing. Therefore, it is possible to surely suppress the increase of the earth and sand pressure in the casing on the opposite side of the fixed blade.
In the invention according to claim 3, the height position of the first through opening in the first region is offset with respect to the height position of the fixed blade in the height direction of the casing. Therefore, the strength of the casing can be improved by arranging the first through opening and the fixed blade so as to avoid cross sections at the same height of the casing.

In the invention according to claim 4, a plurality of rows of first through openings having different height positions are formed in the first region, and the positions of the first through openings of adjacent rows in the height direction in the circumferential direction are staggered from each other. Has been done. Therefore, the casing to be oscillatedly inserted has sufficient strength against the insertion force in the vertical direction and the shearing force in the circumferential direction.
In the invention according to claim 5, as the casing is excavated and inserted into the ground while swinging the casing, the earth and sand from the excavation enter the casing from the lower end of the casing. At this time, since there is a second region in which at least one second through opening is formed below the fixed blade, earth and sand entering below the fixed blade are discharged from the inside to the outside of the casing through the second through opening. Will be done. Therefore, it is possible to prevent sediment from accumulating below the fixed blade when the casing is inserted. This makes it possible to reduce the sediment resistance when the casing is inserted into the ground.

In the invention according to claim 6, the circumferential angle range occupied by the second region is equal to or larger than the circumferential angle range occupied by the fixed blade. Therefore, when the casing is inserted into the ground, it is possible to reliably suppress the accumulation of earth and sand below the fixed blade.
In the invention according to claim 7, since the casing includes a pair of intermediate regions between the first region and the second region, and a pair of non-opening regions extending over the entire height direction, the casing of the casing is provided. Strength is ensured. Therefore, it is possible to prevent buckling and deformation of the casing when the casing is oscillated and inserted into the ground.

In the invention according to claim 8, the angular range in the circumferential direction occupied by each non-opening region is larger than the angular range in the circumferential direction occupied by the second region in which the second through opening is formed. Therefore, when the casing is oscillated and inserted into the ground, it is possible to prevent the casing from buckling or deforming.
In the invention according to claim 9, even if the fixed blade receives the earth and sand pressure due to the earth and sand entering the casing when the casing is oscillated and inserted, there is an opening non-forming region above the fixed blade. The strength can be ensured.

In the invention according to claim 10, the fixed blade is a single fixed blade provided on the inner peripheral surface of the casing at a predetermined height position. Therefore, the structure can be simplified.
In the invention according to claim 11, the existing pile removing device according to any one of claims 1 to 10 is used to swing and insert the casing so as to include the existing pile in an eccentric state, and then to insert the casing into the casing. In the existing pile removing method in which the existing pile is cut by the fixed blade provided on the inner peripheral surface of the casing as the casing rotates, the same effect as that of each of claims 1 to 10 can be obtained.

FIG. 1 is a schematic vertical sectional view of an existing pile removing device according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view of the existing pile removing device, which corresponds to the II-II cross-sectional view of FIG. FIG. 3 is a schematic perspective view of the fixed blade. FIG. 4 is a front view of the fixed blade and its periphery as seen from the inner peripheral surface side of the casing. FIG. 5 is a schematic cross-sectional view of the casing at a height position where a fixed blade is provided. FIG. 6 is a schematic development view of the casing cut open by a vertical cutting line passing through the center position of the fixed blade. 7 (a) to 7 (f) are process diagrams showing each step of the existing pile removing method using the existing pile removing device in order. FIG. 8 is a schematic cross-sectional view of the existing pile removing device, showing a state in which cutting by the fixed blade is completed.

Hereinafter, embodiments embodying the present invention will be described with reference to the drawings.
FIG. 1 is a schematic vertical sectional view of an existing pile removing device according to an embodiment of the present invention. As shown in FIG. 1, the existing pile removing device 1 includes a casing 2, a rotary excavation device 3, an excavation blade 4, a fixed blade 5, and a lifting device 6.
The casing 2 is a vertically long steel cylindrical member. The casing 2 includes an inner peripheral surface 2a, an outer peripheral surface 2b, an upper end 2c, a lower end 2d, a central axis 2e, a first through opening 21, and a second through opening 22. The casing 2 is pushed and inserted into the underground G so as to include the existing columnar pile 10 in an eccentric state (that is, a state in which the central axis 10a of the existing pile 10 is eccentric with respect to the central axis 2e of the casing 2). ..

The rotary excavation device 3 is a device that excavates and inserts the casing 2 into the ground G while rotationally propelling the casing 2 around the central axis 2e in a state of chucking the outer peripheral surface 2b of the casing 2. A plurality of excavation blades 4 are provided. The plurality of excavation blades 4 are fixedly arranged at the lower end 2d of the casing 2 at equal intervals in the circumferential direction C. An actuator such as a hydraulic device (not shown), for example, a double motion of a hydraulic cylinder applies a pushing load to the underground G to the casing 2.

FIG. 2 is a schematic cross-sectional view of the existing pile removing device 1 and corresponds to the II-II cross-sectional view of FIG.
As shown in FIG. 2, in the existing pile 10, a plurality of rod-shaped reinforcing bars 11 arranged at equal intervals in the circumferential direction C are embedded on the circumference 11a centered on the central axis 10a. Although not shown, a reinforcing bar cage is formed by welding and fixing the plurality of reinforcing bars 11 by arranging reinforcing rings surrounding the plurality of reinforcing bars 11 at equal intervals in the height direction. The fixed blade 5 is formed so as to project from a part of the inner peripheral surface 2a of the casing 2 in the circumferential direction C.

FIG. 3 is a schematic perspective view of the fixed blade 5. As shown in FIG. 3, the fixed blade 5 includes a fixed blade main body 50 and a reinforcing rib 51. The fixed blade main body 50 is a horizontal plate portion having a chevron shape when viewed in the direction of the central axis 2e of the casing 2. The fixed blade main body 50 includes an upper surface 50a, a lower surface 50b, and a blade edge surface 50c.
The blade edge surface 50c of the fixed blade main body 50 includes a top portion 52 and a pair of slope portions 53, 54. The top portion 52 of the cutting edge surface 50c is formed of a flat surface orthogonal to the radial direction R of the casing 2 or a concave curved surface (substantially corresponding to a flat surface) having a slight curvature. The pair of slope portions 53, 54 of the cutting edge surface 50c are arranged on both sides of the top 52, and are inclined in a concave shape in opposite directions to each other.

The reinforcing ribs 51 are formed so as to protrude above and below the fixed blade main body 50, that is, on the upper surface 50a and the lower surface 50b. The reinforcing rib 51 is a rectangular plate that extends long in the radial direction R of the casing 2 toward the top 52 of the blade edge surface 50c, which is the top of the fixed blade main body 50. The reinforcing rib 51 improves the strength of the fixed blade 5. Further, the strength of the casing 2 is improved by welding and fixing the reinforcing rib 51 to the casing 2.

The reinforcing rib 51 includes a close end 51a close to the top of the fixed blade main body 50 (the top 52 of the blade edge surface 50c). The close end 51a of the reinforcing rib 51 is formed at the tip of the tapered portion 51b whose height decreases toward the top 52. The top portion 52 and the close end 51a of the reinforcing rib 51 are separated by a predetermined distance L. Therefore, it is suppressed that the reinforcing rib 51 affects the cutting performance of the fixed blade 5. In particular, since the close end 51a of the reinforcing rib 51 is formed at the tip of the tapered portion 51b, it is further suppressed that the reinforcing rib 51 affects the cutting performance of the fixed blade 5.

FIG. 4 is a front view of the fixed blade 5 and its periphery as seen from the inner peripheral surface 2a side of the casing 2. As shown in FIG. 4, the casing 2 includes a second region A2 in which at least one second through opening 22 is formed below the fixed blade 5. In the case of FIG. 4, in the second region A2, the three second through openings 22 are arranged side by side in the circumferential direction C.
FIG. 5 is a schematic cross-sectional view of the casing 2 at the height position where the fixed blade 5 is provided. FIG. 6 is a schematic development view of the casing 2 cut open by a vertical cutting line passing through the central position of the fixed blade 5.

As shown in FIGS. 1, 2 and 6, the casing 2 includes a first region A1 in which a plurality of first through openings 21 are formed side by side in the circumferential direction C on the opposite side of the fixed blade 5.
Further, as shown in FIG. 6, the casing 2 includes a pair of intermediate regions MA between the first region A1 and the second region A2 as regions in which the through openings are not formed, and covers the entire area in the height direction H. Includes a pair of extending non-opening regions A3.

Further, the casing 2 includes an opening non-forming region A4 above the fixed blade 5 as a region where a through opening is not formed. The opening non-forming region A4 above the fixed blade 5 extends from the upper end 2c of the casing 2 to a position adjacent to the fixed blade 5.
As shown in FIG. 5, the angle range CA2 in the circumferential direction C occupied by the second region A2 is equal to (CA2 = C5) or equal to or greater than (CA2 ≧ C5) the angle range C5 in the circumferential direction C occupied by the fixed blade 5. The size. Further, the angle range CA3 in the circumferential direction C occupied by each opening non-forming region A3 is equivalent to (CA3 = C5) or substantially the same (-5 degrees ≦ (CA3)) as the angle range C5 in the circumferential direction C occupied by the fixed blade 5. -C5) ≤ 5 degrees).

As shown in FIG. 6, in the first region A1, a first through opening 21 of a plurality of rows (three rows in the case of FIG. 6) having different height positions is formed. In the first region A1, the positions of the first through openings 21 of the rows adjacent to each other in the height direction H in the circumferential direction C are shifted from each other. That is, the first through openings 21 are arranged in a staggered manner in the circumferential direction C toward the height direction H. As shown in FIG. 5, the angle range CA1 in the circumferential direction occupied by the first region A1 is set to an angle range exceeding 90 degrees and less than 180 degrees (90 degrees <CA1 <180 degrees).

As shown in FIG. 6, the height position of the first through opening 21 of the first region A1 is offset with respect to the height position of the fixed blade 5 with respect to the height direction H of the casing 2. Further, with respect to the height direction H of the casing 2, the height range HA1 of the first region A1 is made larger than the height range H5 of the fixed blade 5 (HA1> H5).
Next, an existing pile removing method using the existing pile removing device 1 will be described. 7 (a) to 7 (f) are process diagrams showing each process of the existing pile removing method in order.

First, as shown in FIG. 7A, a rotary excavator 3 is installed above the existing pile 10 remaining in the underground G, and the rotary excavator 3 is installed at a position eccentric with respect to the existing pile 10 (that is, the existing pile). The casing 2 is set (so that the central axis 10a of 10 and the central axis 2e of the casing 2 are offset) (setting process). At this time, the existing pile 10 is arranged so as to be eccentric to the side opposite to the side where the fixed blade 5 is provided in the casing 2.

Next, as shown in FIG. 7 (b), the rotary excavator 3 swings the casing 2 around the central axis 2e within a range in which the fixed blade 5 does not come into contact with the existing pile 10, and is shown in FIG. 7 (c). It is excavated and inserted into the underground G to a predetermined depth (insertion step).
After the casing 2 reaches a predetermined depth, as shown in FIGS. 7 (d) and 7 (e), the rotary excavator 3 swings the casing 2 so that the swing angle gradually increases, and finally all of the casing 2. As shown in FIG. 8, the fixed blade 5 is rotated around to form a C-shaped cutting groove 12 on the outer peripheral surface 10b of the existing pile 10 (cutting step). The groove bottom 12a of the cutting groove 12 is along the cutting circle 5C by the fixed blade 5 centered on the central axis 2e of the casing 2.

The reinforcing bar 11 at the portion where the C-shaped cutting groove 12 is formed is almost cut to become the cutting reinforcing bar 11C (indicated by a white circle in the figure), and the remaining reinforcing bar 11 is further behind the groove bottom 12a of the cutting groove 12. In the figure, it is the remaining reinforcing bar 11R indicated by the black circle.
Next, a wedge member 7 (see FIG. 7 (f)) is driven between the outer peripheral surface of the upper end of the existing pile 10 and the inner peripheral surface 2a of the casing 2, and the upper end of the existing pile 10 is fixed to the casing 2. By rotating the casing 2 all around, the remaining reinforcing bar 11R in FIG. 8 is threaded, and as shown in FIG. 7 (f), the upper portion 10U of the existing pile 10 above the fixed blade 5 is replaced with the lower portion 10L. Completely break from (thread cutting process).

Next, although not shown, the lifting device 6 grips the upper portion 10U of the existing pile 10 and takes it out from the casing 2 to the ground and removes it (take-out step).
In the present embodiment, the casing 2 is swung around its central axis 2e at a swing angle within a range in which the fixed blade 5 does not interfere with the existing pile 10 so that the cylindrical casing 2 encloses the existing pile 10 in an eccentric state. While excavating and inserting into the underground G. When the casing 2 is oscillated into the ground G, the existing pile 10 is eccentric to the opposite side of the fixed blade 5 with respect to the casing 2, and the inner peripheral surface of the casing 2 is on the opposite side of the fixed blade 5. A wedge-shaped narrowing portion K1 (see FIG. 2) is formed between 2a and the outer peripheral surface 10b of the existing pile 10 in the circumferential direction C.

With the swing insertion of the casing 2, the earth and sand in the casing 2 is pushed into the portion K1 that narrows like a wedge on the opposite side of the fixed blade 5, but the pushed earth and sand is the first on the opposite side of the fixed blade 5. It is discharged to the outer peripheral surface 2b side of the casing 2 through the first through opening 21 of the region A1. Therefore, it is possible to prevent the sediment pressure in the casing 2 from increasing on the opposite side of the fixed blade 5 when the casing 2 is oscillated and inserted. Therefore, it is possible to suppress an increase in the swing resistance when the casing 2 is rocked and inserted, so that the casing 2 can be easily excavated and inserted into the ground.

Further, as shown in FIG. 6, the height range HA1 of the first region A1 is made larger than the height range H5 of the fixed blade 5 with respect to the height direction H of the casing 2 (HA1> H5). Therefore, it is possible to reliably suppress the increase in sediment pressure in the casing 2 on the opposite side of the fixed blade 5.
Further, with respect to the height direction H of the casing 2, the height position of the first through opening 21 of the first region A1 is offset with respect to the height position of the fixed blade 5. Therefore, the strength of the casing 2 can be improved by arranging the first through opening 21 and the fixed blade 5 so as to avoid cross sections of the casing 2 at the same height.

Further, in the first region A1, a plurality of rows of first through openings 21 having different height positions are formed, and the positions of the first through openings 21 of the rows adjacent to each other in the height direction H in the circumferential direction C are displaced from each other. There is. Therefore, the casing 2 to be oscillatedly inserted has sufficient strength against the insertion force in the vertical direction and the shearing force in the circumferential direction C.
Further, as the casing 2 is excavated and inserted into the ground G while swinging, earth and sand from the excavation enter the casing 2 from the lower end 2d of the casing 2. At this time, as shown in FIG. 1, since there is a second region A2 in which at least one second through opening 22 is formed below the fixed blade 5, the earth and sand that enters below the fixed blade 5 is second. It is discharged from the inside to the outside of the casing 2 through the through opening 22. Therefore, it is possible to prevent sediment from accumulating below the fixed blade 5 when the casing 2 is inserted. This makes it possible to reduce the sediment resistance when the casing 2 is inserted into the underground G.

Further, as shown in FIG. 5, the angle range CA2 in the circumferential direction C occupied by the second region A2 is set to be equal to or larger than the angle range C5 in the circumferential direction C occupied by the fixed blade 5 (CA2 ≧). C5). Therefore, when the casing 2 is inserted into the underground G, it is possible to reliably suppress the accumulation of earth and sand below the fixed blade 5.
Further, as shown in FIG. 6, the casing 2 includes a pair of intermediate regions MA between the second region A2 and the first region A1, and a pair of non-opening regions A3 extending over the entire height direction H. Therefore, the strength of the casing 2 is ensured. Therefore, when the casing 2 is oscillatedly inserted into the ground G, it is possible to prevent the casing 2 from buckling or deforming.

Further, even if the fixed blade 5 receives the earth and sand pressure due to the earth and sand entering the casing 2 when the casing 2 is oscillated and inserted, the strength of the casing 2 is obtained because the opening non-forming region A4 is above the fixed blade 5. Can be secured.
Further, the fixed blade 5 is a single fixed blade provided on the inner peripheral surface 2a of the casing 2 at a predetermined height position. Therefore, the structure can be simplified.

Further, in the existing pile removing method using the existing pile removing device 1 of the present embodiment, the same effect as that of the existing pile removing device 1 can be obtained.
The present invention is not limited to the above embodiment, and for example, the angle range CA3 in the circumferential direction C occupied by each opening non-forming region A3 is larger than the angle range CA2 in the circumferential direction C occupied by the second region A2. It may be (CA3> CA2). In this case, the strength of the casing 2 can be increased, and when the casing 2 is oscillatedly inserted into the ground G, buckling or deformation of the casing 2 can be prevented. However, also in this case, the angle range CA2 in the circumferential direction C occupied by the second region A2 is equal to (CA2 = C5) or equal to or greater than (CA2 ≧ C5) the angle range C5 in the circumferential direction C occupied by the fixed blade 5. The size is preferable.

Further, although not shown, a through opening may be formed above the fixed blade 5. In that case, the range of the non-opening region A4 above the fixed blade 5 in the height direction H is narrowed.
Further, although not shown, in the first region A1 on the opposite side of the fixed blade 5, the first through openings 21 may be provided in two rows or four or more rows.
Further, although not shown, the reinforcing rib 51 of the fixed blade 5 may be a rectangular plate having a uniform height. Further, the reinforcing rib 51 may be provided only on either the upper or lower side of the fixed blade main body 50 of the fixed blade 5. Further, the reinforcing rib 51 may be omitted. In addition, the present invention can be modified in various ways within the scope of the claims.

1 Existing pile removal device 2 Casing 2a Inner peripheral surface 2d Lower end 2e Central axis 3 Rotating excavator 4 Excavation blade 5 Fixed blade 6 Lifting device 7 Wedge member 10 Existing pile 10a Central axis 10b Outer peripheral surface 21 First through opening 22 Second penetration Opening A1 1st area A2 2nd area A3 Opening non-forming area A Circular direction C5 Angle range CA1 (of fixed blade) Angle range CA2 (2nd area) Angle range CA3 ( Angle range (of non-opening region) G Underground H Height direction H5 (Fixed blade) Height range HA1 (First region) Height range K1 Wedge-shaped narrowing part MA Intermediate region R Radial direction

The invention according to claim 1 is an existing pile removing device (1) used for cutting and removing an existing pile (10) buried in the ground (G) to a predetermined length, wherein the existing pile is removed. A cylindrical casing (2) that is excavated and inserted into the ground so as to enclose the pile in an eccentric state, and a part of the casing in the circumferential direction (C) at a predetermined height from the lower end (2d) of the casing. A fixed blade (5) projecting and fixed to the inner peripheral surface (2a) of the casing is provided, and the casing is formed with a plurality of first through openings (21) arranged side by side in the circumferential direction on the opposite side of the fixed blade. A first region (A1) that has a height range (HA1) that includes a height range (H5) of the fixed blade with respect to the height direction (H) of the casing . At least one first fixed blade mounting portion in which the fixed blade is mounted in the casing and having a width in the circumferential direction, below the fixed blade mounting portion within the width of the circumferential direction. 2 Provided is an existing pile removing device in which a through opening is formed .

The alphanumerical characters in parentheses represent the corresponding components and the like in the embodiments described later, but this does not mean that the present invention should be limited to those embodiments, of course. The same shall apply hereinafter in this section .

As in claim 2 , the height position of the first through opening in the first region may be offset with respect to the height position of the fixed blade with respect to the height direction of the casing.
As in claim 3 , in the first region, a plurality of rows of first through openings having different height positions are formed, and the positions of the first through openings of adjacent rows in the height direction in the circumferential direction are staggered from each other. It may have been done.

As in claim 4 , the casing is a lower casing portion of the casing within the circumferential width of the fixed blade mounting portion and has the same circumferential width as the fixed blade mounting portion. A sub-second penetration that is formed adjacent to one and the other in the circumferential direction with respect to the casing portion in which the second through opening is formed and is aligned in the circumferential direction with respect to the second through opening (22). A height including a second region (A2) formed including the opening and the second through opening, and a pair of intermediate regions (MA) between the first region and the second region, respectively. A pair of non-opening regions (A3) extending over the entire area of the direction (H) are further included, and the circumferential angular range (CA2) occupied by the second region is the circumferential direction occupied by the fixed blade mounting portion. It may be larger than the angular range (C5) .
As in claim 5 , the circumferential angle range CA3 occupied by each of the non-opening regions is set so as to satisfy the following relational expression with respect to the circumferential angle range C5 occupied by the fixed blade mounting portion. May be.
-5 degrees ≤ (CA3-C5) ≤ 5 degrees

As in claim 6 , the circumferential angle range (CA3) occupied by each of the non-opening regions may be larger than the circumferential angle range (CA2) occupied by the second region (CA3). > CA2).

As in claim 7 , the casing may include an opening non-forming region (A4) above the fixed blade mounting portion within the circumferential width .
As in claim 8 , the fixed blade may be a single fixed blade provided on the inner peripheral surface of the casing at the position of the predetermined height .
The invention according to claim 9 is an existing pile removing method for removing an existing pile buried in the ground by using the existing pile removing device according to any one of claims 1 to 8 . The step of inserting the pile into the ground to a predetermined depth while swinging the casing so as to enclose the pile in an eccentric state, and the fixing by rotating the casing inserted to the predetermined depth around the central axis of the casing. A step of forming a cutting groove on the outer peripheral surface of the existing pile by a blade and cutting the existing pile at the position of the cutting groove, and a step of taking out an upper portion of the cut portion of the existing pile from the casing are included. Provides an existing pile removal method.

In the invention according to claim 1, the casing is swung around the central axis of the casing so that the cylindrical casing encloses the existing pile in an eccentric state, at a swing angle within a range in which the fixed blade does not interfere with the existing pile. , Drill and insert into the ground. At this time, a portion narrowed in a wedge shape in the circumferential direction is formed between the inner peripheral surface of the casing and the outer peripheral surface of the existing pile on the opposite side of the fixed blade. With the swing insertion of the casing, the earth and sand are pushed into the wedge-shaped narrowing portion on the opposite side of the fixed blade, and the pushed earth and sand is the first of the first region arranged on the opposite side of the fixed blade. It is discharged to the outer peripheral surface side of the casing through the through opening. Therefore, it is possible to suppress an increase in the sediment pressure in the casing on the opposite side of the fixed blade.
Further, as the casing is excavated and inserted into the ground while swinging, earth and sand from the excavation enter the casing from the lower end of the casing. At this time, since at least one second through opening is formed in the casing below within the width range of the circumferential width of the fixed blade mounting portion, the earth and sand entering below the fixed blade penetrates the second through. It is discharged from the inside to the outside of the casing through the opening. Therefore, it is possible to prevent sediment from accumulating below the fixed blade when the casing is inserted. This makes it possible to reduce the sediment resistance when the casing is inserted into the ground.

In the invention according to claim 2 , the height position of the first through opening in the first region is offset with respect to the height position of the fixed blade in the height direction of the casing. Therefore, the strength of the casing can be improved by arranging the first through opening and the fixed blade so as to avoid cross sections at the same height of the casing.

In the invention according to claim 3 , a plurality of rows of first through openings having different height positions are formed in the first region, and the positions of the first through openings of adjacent rows in the height direction in the circumferential direction are staggered from each other. Has been done. Therefore, the casing to be oscillatedly inserted has sufficient strength against the insertion force in the vertical direction and the shearing force in the circumferential direction.
In the invention according to claim 4 , as the casing is excavated and inserted into the ground while swinging the casing, the earth and sand from the excavation enter the casing from the lower end of the casing. At this time, at least one second through opening formed in the lower casing portion within the range of the circumferential width of the fixed blade mounting portion, and formed adjacent to one and the other in the circumferential direction of the casing portion, respectively. Since there is a second region including a sub-second through-opening arranged in the circumferential direction with respect to the second through-opening, the earth and sand entering below the fixed blade are the second through-opening and the sub-second through-opening . Through, it is discharged from the inside to the outside of the casing. Therefore, it is possible to prevent sediment from accumulating below the fixed blade when the casing is inserted. This makes it possible to reduce the sediment resistance when the casing is inserted into the ground. Further, since the casing includes a pair of intermediate regions between the first region and the second region and a pair of non-opening regions extending over the entire height direction, the strength of the casing is ensured. Therefore, it is possible to prevent buckling and deformation of the casing when the casing is oscillated and inserted into the ground.

In the invention according to claim 6 , the angular range in the circumferential direction occupied by each non-opening region is larger than the angular range in the circumferential direction occupied by the second region in which the second through opening is formed. Therefore, when the casing is oscillated and inserted into the ground, it is possible to prevent the casing from buckling or deforming.
In the invention according to claim 7 , even if the fixed blade receives the earth and sand pressure due to the earth and sand entering the casing when the casing is oscillated and inserted, the fixed blade is upward within the width range of the circumferential width of the fixed blade mounting portion. Since there is an opening non-forming region in, the strength of the casing can be ensured.

In the invention according to claim 8 , the fixed blade is a single fixed blade provided on the inner peripheral surface of the casing at a position of a predetermined height . Therefore, the structure can be simplified.
In the invention according to claim 9 , the existing pile removing device according to any one of claims 1 to 8 is used to swing and insert the casing so as to include the existing pile in an eccentric state, and then to insert the casing into the casing. In the existing pile removing method in which the existing pile is cut by the fixed blade provided on the inner peripheral surface of the casing as the casing rotates, the same effect as in each of claims 1 to 8 can be obtained.

FIG. 4 is a front view of the fixed blade 5 and its periphery as seen from the inner peripheral surface 2a side of the casing 2. As shown in FIG. 4, the casing 2 is formed with at least one second through opening 22 below the fixed blade mounting portion having a width in the circumferential direction C, which is a fixed blade mounting portion to which the fixed blade 5 is mounted. Has been done. Further, the casing 2 has a casing portion (second penetration) that is a lower casing portion within the width of the circumferential direction C of the fixed blade mounting portion and has the same circumferential direction C width as the fixed blade mounting portion. A secondary second through opening (in FIG. 4, the through openings 22 on both sides correspond to the sub second through opening) is formed adjacent to one and the other in the circumferential direction C with respect to the casing portion in which the opening 22 is formed. Has been done. The sub-second through opening is arranged in the circumferential direction C with respect to the second through opening 22. The casing 2 includes a second region A2 formed including a second through opening 22 and a sub-second through opening . In the case of FIG. 4, in the second region A2, one second through opening 22 and two sub- second through openings 22 are arranged side by side in the circumferential direction C.
FIG. 5 is a schematic cross-sectional view of the casing 2 at the height position where the fixed blade 5 is provided. FIG. 6 is a schematic development view of the casing 2 cut open by a vertical cutting line passing through the central position of the fixed blade 5.

Further, the casing 2 includes an opening non-forming region A4 above the fixed blade mounting portion to which the fixed blade 5 is mounted as a region where the through opening is not formed. The opening non-forming region A4 above the fixed blade mounting portion to which the fixed blade 5 is mounted extends from the upper end 2c of the casing 2 to a position adjacent to the fixed blade 5.
As shown in FIG. 5, the angle range CA2 in the circumferential direction C occupied by the second region A2 is larger than the angle range C5 in the circumferential direction C occupied by the fixed blade mounting portion to which the fixed blade 5 is attached (CA2). > C5) . Further, the angle range CA3 in the circumferential direction C occupied by each opening non-forming region A3 is equivalent to (CA3 = C5) or substantially the same (-5 degrees ≦ (CA3)) as the angle range C5 in the circumferential direction C occupied by the fixed blade 5. -C5) ≤ 5 degrees).

Further, as shown in FIG. 6, with respect to the height direction H of the casing 2, the height range HA1 of the first region A1 includes the height range H5 of the fixed blade 5 (HA1> H5). Therefore, it is possible to reliably suppress the increase in sediment pressure in the casing 2 on the opposite side of the fixed blade 5.
Further, with respect to the height direction H of the casing 2, the height position of the first through opening 21 of the first region A1 is offset with respect to the height position of the fixed blade 5. Therefore, the strength of the casing 2 can be improved by arranging the first through opening 21 and the fixed blade 5 so as to avoid cross sections of the casing 2 at the same height.

Further, in the first region A1, a plurality of rows of first through openings 21 having different height positions are formed, and the positions of the first through openings 21 of the rows adjacent to each other in the height direction H in the circumferential direction C are displaced from each other. There is. Therefore, the casing 2 to be oscillatedly inserted has sufficient strength against the insertion force in the vertical direction and the shearing force in the circumferential direction C.
Further, as the casing 2 is excavated and inserted into the ground G while swinging, earth and sand from the excavation enter the casing 2 from the lower end 2d of the casing 2. At this time, as shown in FIG. 1, since at least one second through opening 22 is formed below the fixed blade mounting portion to which the fixed blade 5 is mounted , earth and sand entering below the fixed blade 5 are formed. , Is discharged from the inside to the outside of the casing 2 through the second through opening 22. Therefore, it is possible to prevent sediment from accumulating below the fixed blade 5 when the casing 2 is inserted. This makes it possible to reduce the sediment resistance when the casing 2 is inserted into the underground G.

Further, as shown in FIG. 5, the angle range CA2 in the circumferential direction C occupied by the second region A2 including the second through opening 22 and the sub-second through opening is occupied by the fixed blade mounting portion to which the fixed blade 5 is attached. It is made larger than the angle range C5 in the circumferential direction C (CA2> C5) . Therefore, when the casing 2 is inserted into the underground G, it is possible to reliably suppress the accumulation of earth and sand below the fixed blade 5.
Further, as shown in FIG. 6, the casing 2 includes a pair of intermediate regions MA between the second region A2 and the first region A1, and a pair of non-opening regions A3 extending over the entire height direction H. Therefore, the strength of the casing 2 is ensured. Therefore, when the casing 2 is oscillatedly inserted into the ground G, it is possible to prevent the casing 2 from buckling or deforming.

Further, even if the fixed blade 5 receives the earth and sand pressure due to the earth and sand entering the casing 2 when the casing 2 is oscillated and inserted, the opening non-forming region A4 is above the fixed blade mounting portion to which the fixed blade 5 is attached. Therefore, the strength of the casing 2 can be ensured.
Further, the fixed blade 5 is a single fixed blade provided on the inner peripheral surface 2a of the casing 2 at a predetermined height position. Therefore, the structure can be simplified.

Further, in the existing pile removing method using the existing pile removing device 1 of the present embodiment, the same effect as that of the existing pile removing device 1 can be obtained.
The present invention is not limited to the above embodiment, and for example, the angle range CA3 in the circumferential direction C occupied by each opening non-forming region A3 is larger than the angle range CA2 in the circumferential direction C occupied by the second region A2. It may be (CA3> CA2). In this case, the strength of the casing 2 can be increased, and when the casing 2 is oscillatedly inserted into the ground G, buckling or deformation of the casing 2 can be prevented .

Claims (11)

An existing pile removal device used to cut and remove existing piles buried in the ground to a predetermined length.
A cylindrical casing that is excavated and inserted into the ground so as to enclose the existing pile in an eccentric state.
A fixed blade, which is projected and fixed to a part of the inner peripheral surface in the circumferential direction of the casing at a position at a predetermined height from the lower end of the casing, is provided.
An existing pile removing device in which the casing includes a first region in which a plurality of first through openings are formed side by side in the circumferential direction on the opposite side of the fixed blade. The existing pile removing device according to claim 1, wherein the height range of the first region is larger than the height range of the fixed blade in the height direction of the casing. The existing pile removal according to claim 1 or 2, wherein the height position of the first through opening in the first region is offset with respect to the height position of the fixed blade with respect to the height direction of the casing. Device. In the first region, a plurality of rows of first through openings having different height positions are formed.
The existing pile removing device according to any one of claims 1 to 3, wherein the positions in the circumferential direction of the first through openings of rows adjacent to each other in the height direction are displaced from each other. The existing pile removing device according to any one of claims 1 to 4, wherein the casing includes a second region in which at least one second through opening is formed below the fixed blade. The existing pile removing device according to claim 5, wherein the circumferential angle range occupied by the second region is equal to or larger than the circumferential angle range occupied by the fixed blade. The existing existing according to claim 5 or 6, wherein the casing includes a pair of intermediate regions between the first region and the second region, and a pair of non-opening regions extending over the entire height direction. Pile removal device. The existing pile removing device according to claim 7, wherein the circumferential angle range occupied by each of the non-opening regions is larger than the circumferential angle range occupied by the second region. The existing pile removing device according to any one of claims 1 to 8, wherein the casing includes a non-opening region above the fixed blade. The existing pile removing device according to any one of claims 1 to 9, wherein the fixed blade is a single fixed blade provided on the inner peripheral surface of the casing at a position of the predetermined height. An existing pile removing method for removing existing piles buried in the ground using the existing pile removing device according to any one of claims 1 to 10.
A process of inserting the existing pile into the ground to a predetermined depth while swinging the casing so as to include the existing pile in an eccentric state.
By rotating the casing inserted to the predetermined depth around the central axis of the casing, a cutting groove is formed on the outer peripheral surface of the existing pile by the fixed blade, and the existing pile is cut at the position of the cutting groove. Process and
A method for removing an existing pile, comprising a step of taking out an upper portion of a cut portion of the existing pile from the casing.

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