JP7041429B2 - Existing pile removal device and existing pile removal method - Google Patents

Description

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

It is difficult to remove the entire existing pile at once. Therefore, the existing pile is cut at a predetermined length from the upper end, and the existing pile is gradually removed from the upper portion.
For example, in Patent Document 1, 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. When the pile is inserted to a predetermined depth, the casing is rotated all around and a cutting groove is formed on the outer peripheral surface of the existing pile by a fixed blade.

After that, an elongated rod-shaped wedge is driven into the gap between the upper part above the cutting groove of the existing pile and the casing to fix the upper part of the existing pile to the casing, and in this state, the casing is attached to the existing pile. The existing pile is sheared by rotating it together with the upper part and threading the upper part of the existing pile together with the remaining reinforcing bar from the lower part.

Japanese Unexamined Patent Publication No. 2018-76732

However, a rod-shaped wedge is arranged on one side in the radial direction of the upper portion of the existing pile, and on the opposite side of the rod-shaped wedge, the upper portion of the existing pile is received by the inner peripheral surface of the casing. Therefore, the fixing force for fixing the upper portion of the existing pile to the casing is weak, and the upper portion of the existing pile may not be able to rotate together with the casing, in which case the existing pile cannot be sheared.

An object of the present invention is to provide an existing pile removing device and an existing pile removing method capable of surely shearing an existing pile.

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. A cylindrical casing (2) that is inserted into the ground so as to enclose the pile in an eccentric state, and the fixing blade (5) is projected and fixed to the inner peripheral surface (2a) at a predetermined height from the lower end (2d). ) And the downward wedge-shaped first wedge jig (6) and second wedge jig (7) that are inserted and arranged in the casing and sandwich the head (10H) of the existing pile and wedge-fix to the casing. And provides an existing pile removal device.

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 first wedge jig is on the opposite side (E2) of the eccentric direction (E1) of the existing pile with respect to the casing, and the outer peripheral surface (10b) of the head of the existing pile and the casing. The existing pile is suspended from the inner peripheral surface of the above, and the second wedge jig is suspended from the first wedge jig on the opposite side of the first wedge jig. The head of the existing pile is sandwiched between the first wedge jig and the second wedge jig by being pushed and inserted between the outer peripheral surface of the head and the inner peripheral surface of the casing. It may be configured to be fixed to the casing.

As in claim 3, the second wedge jig has a cylindrical outer surface (7c) facing the inner peripheral surface of the casing and an inner surface (7d) facing the outer peripheral surface of the existing pile. ), And the inner side surface is inclined downward with respect to the vertical direction (V) and inclined with respect to the circumferential direction so as to face one side (C1) of the circumferential direction (C) of the casing. It may have an inclined portion (71).

As in claim 4, the second wedge jig includes a lower portion (7L) and an upper portion (7U) arranged above the lower portion, and the lower portion is the said. The inner side surface has a first inclined portion (71) as the inclined portion, and the upper side portion is adjacent to the upper side of the first inclined portion on the inner side surface and faces the one side in the circumferential direction. Has a second inclined portion (72) inclined with respect to the circumferential direction, and is formed between the second inclined portion and the outer surface of the upper portion when viewed in the vertical direction. The cross-sectional area (S2) of the wedge-shaped portion (72K) is the maximum value of the cross-sectional area (S1) of the first wedge-shaped portion (71K) formed between the first inclined portion of the lower portion and the outer surface. It may be equal to (S2 = S1MAX) equal to (S1MAX) or equal to or higher than (S2 ≧ S1MAX).

As in claim 5, the second inclined portion of the upper portion of the second wedge jig may be a vertical surface.
As in claim 6, a plurality of vertical ribs (7 g) may be formed so as to protrude on the inner surface of the second wedge jig.
As in claim 7, a plurality of friction increasing ribs (7h) may be formed so as to protrude on the outer surface of the second wedge jig.

The invention according to claim 8 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 7. The insertion 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 rotation of the casing in the circumferential direction at a position at a predetermined depth from the head of the existing pile. The cutting groove forming step of forming a cutting groove on the outer peripheral surface of the existing pile, and the head of the existing pile in which the cutting groove is formed are sandwiched between the first wedge jig and the second wedge jig to form the casing. Provided is an existing pile removing method including a shearing step of swinging the casing in the circumferential direction and shearing the existing pile in the cutting groove while being fixed to the pile.

As in claim 9, between the insertion step and the cutting groove forming step, the outer peripheral surface of the head of the existing pile and the inner circumference of the casing on the opposite side of the eccentric direction of the existing pile with respect to the casing. The first wedge jig hanging step of suspending the first wedge jig between the surface and the surface in a loosely fitted state is included, and the cutting groove forming step is performed in a state where the first wedge jig is suspended. You may be wedged.
As in claim 10, between the cutting groove forming step and the shearing step, the outer peripheral surface of the head of the existing pile and the inner peripheral surface of the casing on the opposite side of the first wedge jig. By pushing and inserting the second wedge jig between the first wedge jig and the second wedge jig, the head of the existing pile is sandwiched between the first wedge jig and the second wedge jig and fixed to the casing. It may include a fixing step.

As in claim 11, the second wedge jig has an inclined portion on the inner surface surface that is inclined downward with respect to the vertical direction and inclined with respect to the circumferential direction so as to face one side of the circumferential direction. In the fixing step, the tilting portion of the second wedge jig tilts the head of the existing pile toward the one side in the circumferential direction by pushing and inserting the second wedge jig. Force may be applied.

As in claim 12, the second wedge jig includes a lower portion, an upper portion arranged above the lower portion, and an outer surface, and the lower portion is the inner surface surface. Has a first inclined portion as the inclined portion, and the upper portion thereof is adjacent to the upper side of the first inclined portion on the inner side surface and faces the one side in the circumferential direction with respect to the circumferential direction. The cross-sectional area of the second wedge-shaped portion formed between the second inclined portion and the outer surface of the upper portion when viewed in the vertical direction is the lower portion. The maximum value of the cross-sectional area of the first wedge-shaped portion formed between the first inclined portion of the side portion and the outer surface thereof is equal to or greater than the maximum value, and in the fixing step, the first wedge jig is used. The head of the existing pile is sandwiched between and the first inclined portion of the lower portion of the second wedge jig, and in the shearing step, the casing is placed on the one side in the circumferential direction. As the second wedge jig is rotated toward, the upper portion of the existing pile bends the portion above the cutting groove of the existing pile with respect to the lower portion of the existing pile. It may be depressed between the outer peripheral surface of the head and the inner peripheral surface of the casing.

In the existing pile removing device according to the invention of claim 1, the casing inserted in the ground is rotated in the circumferential direction so as to enclose the existing pile in an eccentric state, and the fixed blade is used to rotate the casing from the head of the existing pile. A cutting groove is formed on the outer peripheral surface of the existing pile at a predetermined depth. The head of the existing pile in which the cutting groove is formed is sandwiched between the downward wedge-shaped first wedge jig and the second wedge jig, and the casing is firmly wedge-fixed to the casing, and the casing is placed in the circumferential direction. By swinging, the existing pile can be reliably sheared together with the remaining reinforcing bar at the portion of the cutting groove while twisting the portion of the existing pile above the cutting groove with respect to the portion below. ..

In the invention according to claim 2, in a state where the first wedge jig is suspended and arranged in advance on the opposite side of the existing pile in the eccentric direction, the second wedge jig is pushed and inserted on the opposite side of the first wedge jig. do. Therefore, the head of the existing pile can be securely sandwiched and firmly wedge-fixed to the casing.
In the invention according to claim 3, the inclined portion of the inner surface of the second wedge jig is not only inclined downward with respect to the vertical direction, but also in the circumferential direction so as to face one side in the circumferential direction of the casing. It is tilted with respect to. Therefore, when the second wedge jig is pushed downward and inserted, a tilting force (lateral force) that tilts the head of the existing pile toward the one side in the circumferential direction is applied by the tilted portion. Will be done. This makes it possible to prompt the bending direction of the existing pile in a predetermined direction.

In the invention according to claim 4, when viewed in the vertical direction, the cross-sectional area of the second wedge-shaped portion formed between the second inclined portion and the outer surface of the upper portion of the second wedge jig is lower. It is equal to or equal to or greater than the maximum cross-sectional area of the first wedge-shaped portion formed between the first inclined portion of the side portion and the outer surface. Therefore, as the head of the existing pile sandwiched between the first wedge jig and the first inclined portion of the lower portion of the second wedge jig is rotated together with the casing to the one side in the circumferential direction, The head of the existing pile is largely pushed in the predetermined direction so that the upper portion of the second wedge jig falls between the outer peripheral surface of the head of the existing pile and the inner peripheral surface of the casing. Therefore, the shearing effect of shearing the existing pile can be significantly improved.

In the invention according to claim 5, the second inclined portion of the upper portion of the second wedge jig is a vertical surface. Therefore, the structure of the second wedge jig can be simplified and the structure of the second wedge jig can be simplified as compared with the case where the second inclined portion of the upper portion of the second wedge jig is inclined downward with respect to the vertical plane. 2 The size of the wedge jig can be reduced.
In the invention according to claim 6, the binding force to the existing pile can be increased by the plurality of vertical ribs protruding from the inner surface of the second wedge jig.

In the invention according to claim 7, the second wedge jig is held so as not to rotate relative to the casing by a plurality of friction increasing ribs formed so as to project on the outer surface of the second wedge jig.
In the existing pile removing method according to the invention according to claim 8, in the shearing step, the head of the existing pile having a cutting groove formed on the outer peripheral surface at a predetermined depth from the head is the first wedge jig. The casing is swung in the circumferential direction while being sandwiched between the second wedge jig and the second wedge jig and firmly wedge-fixed to the casing. Therefore, the existing pile can be reliably sheared together with the remaining reinforcing bar at the portion of the cutting groove while twisting the portion above the cutting groove of the existing pile with respect to the portion below.

In the invention according to claim 9, the cutting groove forming step is a first wedge jig between the outer peripheral surface of the head of the existing pile and the inner peripheral surface of the casing on the opposite side of the eccentric direction of the existing pile with respect to the casing. Is suspended in a loosely fitted state. Therefore, when forming the cutting groove, it is possible to prevent the existing pile and the casing from rotating and hindering the formation of the cutting groove. Further, if the head of the existing pile falls down with the completion of the formation of the cutting groove, it can be received by the first wedge jig.

In the invention according to claim 10, in the fixing step between the cutting groove forming step and the shearing step, the first wedge jig is pushed and inserted on the opposite side of the first wedge jig. The head of the existing pile can be sandwiched between the second wedge jig and the second wedge jig and firmly wedge-fixed to the casing.
In the invention according to claim 11, the inclined portion of the inner surface of the second wedge jig is not only inclined downward with respect to the vertical direction, but also in the circumferential direction so as to face one side in the circumferential direction of the casing. It is tilted with respect to. Therefore, in the fixing step, when the second wedge jig is pushed downward and inserted, the tilting force (lateral direction) that causes the tilted portion to tilt toward the one side in the circumferential direction with respect to the head of the existing pile. Power) is given. This makes it possible to prompt the bending direction of the existing pile in a predetermined direction.

In the invention according to claim 12, when viewed in the vertical direction, the cross-sectional area of the second wedge-shaped portion formed between the second inclined portion and the outer surface of the upper portion of the second wedge jig is lower. It is equal to or equal to or greater than the maximum cross-sectional area of the first wedge-shaped portion formed between the first inclined portion of the side portion and the outer surface. Therefore, in the shearing step, when the head of the existing pile sandwiched between the first wedge jig and the first inclined portion of the lower portion of the second wedge jig is swung in the circumferential direction together with the casing, The head of the existing pile is largely pushed in the predetermined direction so that the upper portion of the second wedge jig falls between the outer peripheral surface of the head of the existing pile and the inner peripheral surface of the casing. Therefore, the shearing effect of shearing the existing pile can be significantly improved.

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 schematic perspective view of the first wedge jig and the second wedge jig. FIG. 5 is a schematic vertical sectional view of the first wedge jig and the second wedge jig, and schematically shows a state in which the head of the existing pile is sandwiched between the first wedge jig and the second wedge jig. There is. FIG. 6A is a cross-sectional view of the upper portion of the second wedge jig, and corresponds to the UU cross-sectional view of FIG. FIG. 6B is a cross-sectional view of the lower portion of the second wedge jig, and corresponds to the LL cross-sectional view of FIG. 7 (a) to 7 (i) are process diagrams sequentially showing each process in the existing pile removing direction using the existing pile removing device. FIG. 8 is a schematic cross-sectional view of the existing pile removing device, showing a state in which a cutting groove is formed in the existing pile.

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 having an excavation blade 4 and a fixed blade 5, a rotary excavation device 3, a downward wedge-shaped first wedge jig 6, and a downward wedge-shaped second wedge. A jig 7 and a lifting device 8 are provided. The first wedge jig 6 and the second wedge jig 7 are each suspended by a rope 9 by a crane (not shown) or the like and moved up and down.

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, an excavation blade 4, and a fixed blade 5. The casing 2 contains the existing columnar pile 10 in an eccentric state (specifically, a state in which the central axis 10a of the existing pile 10 is eccentric to the central axis 2e of the casing 2 in the eccentric direction E1). It is pushed and inserted into the middle G.

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 (that is, in the circumferential direction C) 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 and extending in the vertical direction 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 schematic perspective view of the first wedge jig 6 and the second wedge jig 7. FIG. 5 is a schematic vertical sectional view of the first wedge jig 6 and the second wedge jig 7, in which the head portion 10H of the existing pile 10 is sandwiched between the first wedge jig 6 and the second wedge jig 7. Is schematically shown.
As shown in FIGS. 4 and 5, the first wedge jig 6 includes an upper surface 6a, a lower surface 6b, an outer surface 6c, an inner surface 6d, and a pair of circumferential end surfaces 6e. The upper surface 6a and the lower surface 6b are formed on a horizontal plane. The pair of circumferential end faces 6e are formed in a vertical plane. The outer side surface 6c is a surface facing the inner peripheral surface 2a of the casing 2, and is formed of a cylindrical surface having the same or substantially the same curvature as the inner peripheral surface 2a of the casing 2.

The inner side surface 6d is a surface facing the outer peripheral surface 10b of the existing pile 10. In the vertical cross section of the first wedge jig 6, the inner side surface 6d is inclined downward with respect to the vertical direction to form an inclined surface facing downward. In the cross section of the first wedge jig 6, the inner side surface 6d has an arc shape having the same or substantially the same curvature as the outer peripheral surface 10b of the existing pile 10.
As shown in FIGS. 4 and 5, the second wedge jig 7 includes an upper surface 7a, a lower surface 7b, an outer surface 7c, an inner surface 7d, and a pair of circumferential end surfaces 7e and 7f. The upper surface 7a and the lower surface 7b are formed on a horizontal plane. The pair of circumferential end faces 7e and 7f are formed in a vertical plane.

The outer side surface 7c is a surface facing the inner peripheral surface 2a of the casing 2, and is formed of a cylindrical surface having the same or substantially the same curvature as the inner peripheral surface 2a of the casing 2. As shown in FIG. 4, a plurality of vertical ribs 7g are formed on the inner side surface 7d so as to project from each other with a space between them in the lateral direction (circumferential direction C). Further, on the outer surface 7c, a large number of friction increasing ribs 7h such as vertical ribs for increasing the friction of the inner peripheral surface 2a of the casing 2 are formed so as to project.

Further, the second wedge jig 7 includes a lower portion 7L and an upper portion 7U arranged above the lower portion 7L. FIG. 6A is a cross-sectional view of the upper portion 7U of the second wedge jig 7, and corresponds to the UU cross-sectional view of FIG. FIG. 6B is a cross-sectional view of the lower portion 7L of the second wedge jig 7, and corresponds to the LL cross-sectional view of FIG.
As shown in FIGS. 4 and 5, the inner side surface 7d of the lower portion 7L includes the first inclined portion 71. The first inclined portion 71 is inclined downward with respect to the vertical direction V as shown in FIG. 5, and is inclined with respect to the circumferential direction C so as to face one side C1 of the circumferential direction C as shown in FIG. 6B. Tilt. That is, in the lower portion 7L, there is a vertical V wedge-shaped portion (see FIG. 5) that narrows downward between the first inclined portion 71 of the inner side surface 7d and the outer surface 6c, and the circumference thereof. A first wedge-shaped portion 71K, which is a wedge-shaped portion (see FIG. 6B) in the circumferential direction C that becomes narrower toward one side C1 of the direction C, is formed.

As shown in FIGS. 4 and 5, the inner side surface 7d of the upper portion 7U includes the second inclined portion 72. The second inclined portion 72 is a vertical surface (see FIG. 5) that is inclined with respect to the circumferential direction C so as to face one side C1 of the circumferential direction C. That is, as shown in FIG. 6A, in the upper portion 7U, between the second inclined portion 72 of the inner side surface 7d and the outer surface 7c, a wedge shape in the circumferential direction C that becomes narrower toward one side C1 in the circumferential direction C. A second wedge-shaped portion 72K, which is a portion, is formed.

As shown in FIG. 4, the first inclined portion 71 of the inner side surface 7d of the lower portion 7L has an upper edge 71a, a lower edge 71b, one side edge 71c of one side C1 in the circumferential direction C, and another side edge. Includes 71d. The second inclined portion 72 of the inner side surface 7d of the upper portion 7U includes an upper edge 72a, a lower edge 72b, one side edge 72c of one side C1 in the circumferential direction C, and the other side edge 72d.
The upper edge 71a of the first inclined portion 71 coincides with the lower edge 72b of the second inclined portion 72, and the second inclined portion 72 is vertically facing. Therefore, when viewed in the vertical direction V, the cross-sectional area S2 (see FIG. 6A) of the second wedge-shaped portion 72K of the upper portion 7U of the second wedge jig 7 is the first wedge-shaped portion 71K of the lower portion 7L. The cross-sectional area S1 (see FIG. 6B) is equivalent to the maximum value S1MAX (S2 = S1MAX).

Further, as shown in FIGS. 4 and 6B, the inner side surface 7d of the lower portion 7L is a first extending portion extending from one side edge 71c of the first inclined portion 71 to one side C1 in the circumferential direction C. 73 is included. The first extending portion 73 is inclined downward with a slight inclination angle with respect to the vertical plane orthogonal to the radial direction R of the casing 2.
Further, as shown in FIGS. 4 and 6A, the inner side surface 7d of the upper portion 7U is a second extending portion 74 extending from one side edge 72c of the second inclined portion 72 to one side C1 in the circumferential direction C. including. The second extending portion 74 is formed in a vertical plane orthogonal to the radial direction R of the casing 2.

Next, an existing pile removing method using the existing pile removing device 1 will be described. 7 (a) to 7 (i) are process diagrams sequentially showing each process of the existing pile removing method.
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 FIG. 7D, the first wedge jig 6 is on the opposite side E2 of the eccentric direction E1 of the existing pile 10 with respect to the casing 2 and the head of the existing pile 10. It is suspended and arranged in a loosely fitted state between the outer peripheral surface 10b of 10H and the inner peripheral surface 2a of the casing 2 (first wedge jig hanging step).

As shown in FIG. 7 (e), the first wedge jig 6 is freed between the outer peripheral surface 10b of the head portion 10H of the existing pile 10 and the inner peripheral surface 2a of the casing 2 on the opposite side E2 of the eccentric direction E1. In the state of being suspended in the fitted state, the casing 2 is rotated all around to one side C1 in the circumferential direction by the rotary excavator 3, and as shown in FIGS. 7 (f) and 8 is existing by the fixed blade 5. A C-shaped cutting groove 12 is formed on the outer peripheral surface 10b of the pile 10 (cutting groove forming step). As shown in FIG. 8, 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, as shown in FIGS. 7 (g) and 5, on the opposite side of the first wedge jig 6, between the outer peripheral surface 10b of the head portion 10H of the existing pile 10 and the inner peripheral surface 2a of the casing 2. 2 By weighting the wedge jig 7 with its own weight or weight and pushing it downward, the head 10H of the existing pile 10 is sandwiched between the first wedge jig 6 and the second wedge jig 7 to form a casing. Fix to 2 (fixing process).

Next, with the head portion 10H of the existing pile 10 fixed to the casing 2 between the first wedge jig 6 and the second wedge jig 7, the casing 2 is rotated in the circumferential direction as shown in FIG. 7 (h). By swinging to C, the residual reinforcing bar 11R in FIG. 8 is threaded, and as shown in FIG. 7 (i), the upper portion 10U of the existing pile 10 above the fixed blade 5 is compared with the lower portion 10L. While twisting, the existing pile 10 is surely sheared at the portion of the cutting groove 12 to completely break it (shearing step).

Next, although not shown, the lifting device 8 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).
The existing pile removing device 1 according to the present embodiment has the following effects.
That is, by rotating the casing 2 inserted into the underground G so as to include the existing pile 10 in an eccentric state, the existing pile 10 is placed at a predetermined depth from the head portion 10H of the existing pile 10 by the fixed blade 5. A cutting groove 12 is formed on the outer peripheral surface 10b (see FIG. 7 (f)). As shown in FIGS. 7 (g) and 7 (h), the head portion 10H of the existing pile 10 in which the cutting groove 12 is formed is sandwiched between the downward wedge-shaped first wedge jig 6 and the second wedge jig 7. By swinging the casing 2 in the circumferential direction C with the head portion 10H firmly wedge-fixed to the casing 2, as shown in FIG. 7 (i), the head portion 10H is above the cutting groove 12 of the existing pile 10. While twisting the upper portion 10U with respect to the lower portion 10L, the existing pile 10 can be reliably sheared together with the remaining reinforcing bar 11R at the portion of the cutting groove 12.

Further, as shown in FIG. 7 (f), as shown in FIG. 7 (g), the first wedge jig 6 is suspended and arranged in advance on the opposite side E2 of the eccentric direction E1 of the existing pile 10. The second wedge jig 7 is pushed into the opposite side of the first wedge jig 6. Therefore, the head portion 10H of the existing pile 10 can be securely sandwiched and firmly wedge-fixed to the casing 2.
Further, as shown in FIGS. 4 and 5, the inclined portion (first inclined portion 71) of the inner side surface 7d of the second wedge jig 7 is not only inclined downward with respect to the vertical direction V, but also. As shown in FIGS. 4 and 6B, the casing 2 is inclined with respect to the circumferential direction C so as to face one side C1 of the circumferential direction C. Therefore, when the second wedge jig 7 is pushed downward and inserted, the inclined portion (first inclined portion 71) tilts the existing pile 10 toward the head portion 10H of the existing pile 10 toward one side C1 in the circumferential direction C. Tilt force (lateral force) is applied. As a result, the bending direction of the existing pile 10 can be prompted in a predetermined direction.

Further, when viewed in the vertical direction V, as shown in FIGS. 6A and 6B, a second formed between the second inclined portion 72 of the upper portion 7U of the second wedge jig 7 and the outer surface 7c. The cross-sectional area S2 of the wedge-shaped portion 72K is equivalent to the maximum value S1MAX of the cross-sectional area S1 of the first wedge-shaped portion 71K formed between the first inclined portion 71 of the lower portion 7L and the outer surface 7c (S2 = S1MAX). It is said that.
Therefore, the head portion 10H of the existing pile 10 sandwiched between the first wedge jig 6 and the first inclined portion 71 of the lower portion 7L of the second wedge jig 7 is swung in the circumferential direction C together with the casing 2. As a result, the upper portion 7U of the second wedge jig 7 falls between the outer peripheral surface 10b of the head portion 10H of the existing pile 10 and the inner peripheral surface 2a of the casing 2, so that the head of the existing pile 10 falls. The portion 10H is largely pushed in the predetermined direction. Therefore, the shearing effect of shearing the existing pile 10 can be remarkably improved, and the existing pile 10 can be sheared more reliably.

Further, as shown in FIGS. 4 and 5, the second inclined portion 72 of the upper portion 7U of the second wedge jig 7 is vertically facing. Therefore, the structure of the second wedge jig 7 can be simplified as compared with the case where the second inclined portion 72 of the upper portion 7U of the second wedge jig 7 is inclined downward with respect to the vertical plane. Further, the size of the second wedge jig 7 can be reduced.
Further, the binding force on the existing pile 10 can be increased by the plurality of vertical ribs 7g (see FIG. 4) protruding from the inner side surface 7d of the second wedge jig 7.

Further, the second wedge jig 7 is held so as not to rotate relative to the casing 2 by the plurality of friction increasing ribs 7h (see FIG. 4) protruding from the outer surface 7c of the second wedge jig 7. Ru.
In addition, the existing pile removal method according to the present embodiment has the following effects.
That is, in the shearing step, the head portion 10H of the existing pile 10 in which the cutting groove 12 is formed on the outer peripheral surface 10b at a predetermined depth from the head portion 10H is the first wedge cutting as shown in FIG. 7 (g). As shown in FIG. 7 (h), the casing 2 is swung in the circumferential direction C while being sandwiched between the tool 6 and the second wedge jig 7 and firmly wedge-fixed to the casing 2. Therefore, as shown in FIG. 7 (i), while twisting the upper portion 10U above the cutting groove 12 of the existing pile 10 with respect to the lower portion 10L, the existing pile 10 is formed in the portion of the cutting groove 12. It can be reliably sheared together with the residual reinforcing bar 11R.

Further, in the cutting groove forming step, as shown in FIG. 7 (f), the outer peripheral surface 10b of the head portion 10H of the existing pile 10 and the inner circumference of the casing 2 are formed on the opposite side E2 of the eccentric direction E1 of the existing pile 10 with respect to the casing 2. The first wedge jig 6 is suspended from the surface 2a in a loosely fitted state. Therefore, when forming the cutting groove 12, it is possible to prevent the existing pile 10 and the casing 2 from rotating and hindering the formation of the cutting groove 12. Further, if the head portion 10H of the existing pile 10 falls down with the completion of the formation of the cutting groove 12, the first wedge jig 6 can receive this.

Further, in the fixing step between the cutting groove forming step and the shearing step, as shown in FIG. 7 (g), the second wedge jig 7 is pushed and inserted into the opposite side of the first wedge jig 6. The head portion 10H of the existing pile 10 can be sandwiched between the first wedge jig 6 and the second wedge jig 7 and firmly wedge-fixed to the casing 2.
Further, as shown in FIGS. 4 and 5, the inclined portion (first inclined portion 71) of the inner side surface 7d of the second wedge jig 7 is not only inclined downward with respect to the vertical direction V, but also. As shown in FIGS. 4 and 6B, the casing 2 is inclined with respect to the circumferential direction C so as to face one side C1 of the circumferential direction C. Therefore, in the fixing step, when the second wedge jig 7 is pushed downward and inserted, the inclined portion (first inclined portion 71) causes one side of the circumferential direction C with respect to the head portion 10H of the existing pile 10. A tilting force (lateral force) that tilts to C1 is applied. As a result, the bending direction of the existing pile 10 can be prompted in a predetermined direction.

Further, when viewed in the vertical direction V, as shown in FIGS. 6A and 6B, a second formed between the second inclined portion 72 of the upper portion 7U of the second wedge jig 7 and the outer surface 7c. The cross-sectional area S2 of the wedge-shaped portion 72K is equivalent to the maximum value S1MAX of the cross-sectional area S1 of the first wedge-shaped portion 71K formed between the first inclined portion 71 of the lower portion 7L and the outer surface 7c (S2 = S1MAX). It is said that.
Therefore, in the shearing step, the head portion 10H of the existing pile 10 sandwiched between the first wedge jig 6 and the first inclined portion 71 of the lower portion 7L of the second wedge jig 7 is connected to the casing 2 in the circumferential direction C. The upper portion 7U of the second wedge jig 7 falls between the outer peripheral surface 10b of the head portion 10H of the existing pile 10 and the inner peripheral surface 2a of the casing 2 as the second wedge jig 7 is swung. The head portion 10H of the pile 10 is largely pushed in the predetermined direction. Therefore, the shearing effect of shearing the existing pile 10 can be significantly improved.

The present invention is not limited to the above embodiment, and for example, although not shown, the second inclined portion 72 of the upper portion 7U of the second wedge jig 7 is one side of the circumferential direction C of the casing 2. Not only may it be inclined with respect to the circumferential direction C so as to face C1, but it may also be inclined downward with respect to the vertical direction V.
In this case, the cross-sectional area S2 of the second wedge-shaped portion 72K formed between the second inclined portion 72 of the upper portion 7U of the second wedge jig 7 and the outer surface 7c is the first of the lower portion 7L. It is equal to or higher than the maximum value S1MAX of the cross-sectional area S1 of the first wedge-shaped portion 71K formed between the inclined portion 71 and the outer surface 7c (S2 ≧ S1MAX). Therefore, in the shearing step, the upper portion 7U of the second wedge jig 7 falls between the outer peripheral surface 10b of the head portion 10H of the existing pile 10 and the inner peripheral surface 2a of the casing 2, thereby causing the existing pile 10 to fall. The shearing effect of pushing the head portion 10H more greatly to shear the existing pile 10 can be further enhanced.

Further, in the cutting groove forming step, the casing 2 may be swung so as to gradually increase the swing angle in the circumferential direction C so that the casing 2 is finally rotated all around.
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 Rotary excavator 4 Excavation blade 5 Fixed blade 6 1st wedge jig 7 2nd wedge jig 7L Lower part 7U Upper part 7c Outer side surface 7d Inner Side surface 7g Vertical rib 7h Friction increasing rib 8 Lifting device 10 Existing pile 10H Head 10L Lower part 10U Upper part 10a Central axis 10b Outer peripheral surface 11 Reinforcing bar 11C Cutting reinforcing bar 11R Remaining reinforcing bar 12 Cutting groove 71 First inclined part 71K First wedge shape Part 72 2nd inclined part 72K 2nd wedge-shaped part 73 1st extension part 74 2nd extension part C Circumferential direction C1 One side E eccentric direction E1 Eccentric direction E1 Opposite side G Underground R diameter Direction S1 Cross-sectional area (of the first wedge-shaped part) S2 Cross-sectional area (of the second wedge-shaped part) V Vertical direction

Claims (12)

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 inserted into the ground so as to enclose the existing pile in an eccentric state, and a fixed blade is projected and fixed to the inner peripheral surface at a position at a predetermined height from the lower end.
An existing pile removing device including a downward wedge-shaped first wedge jig and a second wedge jig that are inserted and arranged in the casing and are wedge-fixed to the casing by sandwiching the head of the existing pile. The first wedge jig is suspended and arranged between the outer peripheral surface of the head of the existing pile and the inner peripheral surface of the casing on the opposite side of the existing pile in the eccentric direction with respect to the casing.
With the first wedge jig suspended and arranged, the second wedge jig is on the opposite side of the first wedge jig to the outer peripheral surface of the head of the existing pile and the inside of the casing. The head of the existing pile is configured to be sandwiched between the first wedge jig and the second wedge jig and fixed to the casing by being pushed and inserted between the peripheral surface and the peripheral surface. The existing wedge removing device according to claim 1. The second wedge jig includes a cylindrical outer surface facing the inner peripheral surface of the casing and an inner surface facing the outer peripheral surface of the existing pile.
The existing pile removing device according to claim 2, wherein the inner side surface has an inclined portion inclined downward with respect to the vertical direction and inclined with respect to the circumferential direction so as to face one side of the circumferential direction of the casing. .. The second wedge jig includes a lower portion and an upper portion disposed above the lower portion.
The lower portion has a first inclined portion as the inclined portion on the inner side surface thereof.
The upper portion has a second inclined portion on the inner side surface that is adjacent to the upper side of the first inclined portion and is inclined with respect to the circumferential direction so as to face the one side in the circumferential direction.
When viewed in the vertical direction, the cross-sectional area of the second wedge-shaped portion formed between the second inclined portion and the outer surface of the upper portion is the first inclined portion and the outer side of the lower portion. The existing pile removing device according to claim 3, wherein the maximum value of the cross-sectional area of the first wedge-shaped portion formed between the side surface and the side surface is equal to or greater than the maximum value. The existing pile removing device according to claim 4, wherein the second inclined portion of the upper portion of the second wedge jig faces a vertical surface. The existing pile removing device according to any one of claims 1 to 5, wherein a plurality of vertical ribs are projected and formed on the inner surface of the second wedge jig. The existing pile removing device according to any one of claims 1 to 6, wherein a plurality of friction increasing ribs are projected and formed on the outer surface of the second wedge jig. 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 7.
An insertion step 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.
A cutting groove forming step of rotating the casing in the circumferential direction to form a cutting groove on the outer peripheral surface of the existing pile at a position at a predetermined depth from the head of the existing pile.
In a state where the head of the existing pile in which the cutting groove is formed is sandwiched between the first wedge jig and the second wedge jig and fixed to the casing, the casing is swung in the circumferential direction. An existing pile removing method comprising a shearing step of shearing an existing pile in the cutting groove. Between the insertion step and the cutting groove forming step, on the opposite side of the eccentric direction of the existing pile with respect to the casing, between the outer peripheral surface of the head of the existing pile and the inner peripheral surface of the casing. 1 Including the process of suspending the 1st wedge jig in a loosely fitted state, including the process of suspending the 1st wedge jig.
The existing pile removing method according to claim 8, wherein the cutting groove forming step is performed in a state where the first wedge jig is suspended. Between the cutting groove forming step and the shearing step, the second side between the outer peripheral surface of the head of the existing pile and the inner peripheral surface of the casing on the opposite side of the first wedge jig. The claim comprises a fixing step of sandwiching the head of the existing pile between the first wedge jig and the second wedge jig and fixing the wedge jig to the casing by pushing and inserting the wedge jig. The existing pile removing method according to 9. The second wedge jig has an inclined portion on the inner surface surface that is inclined downward with respect to the vertical direction and inclined with respect to the circumferential direction so as to face one side of the circumferential direction.
In the fixing step, by pushing and inserting the second wedge jig, the tilting portion of the second wedge jig imparts a tilting force that tilts the head of the existing pile toward the one side in the circumferential direction. The existing pile removing method according to claim 10. The second wedge jig includes a lower portion, an upper portion arranged on the upper side of the lower portion, and an outer surface, and the lower portion has a second inner surface surface as the inclined portion. A second inclined portion having one inclined portion and having the upper portion inclined with respect to the circumferential direction so as to be adjacent to the upper side of the first inclined portion on the inner surface surface and to face the one side in the circumferential direction. When viewed in the vertical direction, the cross-sectional area of the second wedge-shaped portion formed between the second inclined portion of the upper portion and the outer surface thereof is the first inclined portion of the lower portion. It is equal to or equal to or greater than the maximum cross-sectional area of the first wedge-shaped portion formed between the portion and the outer surface.
In the fixing step, the head of the existing pile is sandwiched between the first wedge jig and the first inclined portion of the lower portion of the second wedge jig.
In the shearing step, as the casing is rotated toward the one side in the circumferential direction, the upper portion of the second wedge jig is formed on the upper portion of the existing pile with respect to the cutting groove. The method for removing an existing pile according to claim 11, wherein the pile falls between the outer peripheral surface of the head of the existing pile and the inner peripheral surface of the casing while being bent with respect to the lower portion.

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