JP2021173031A - How to remove existing piles - Google Patents

Abstract

To prevent debris from falling into edge-cut holes around existing piles when cutting the existing piles, and smoothly improve muddy water in the holes after removing the existing piles to the same level as the surrounding ground.SOLUTION: In removing an existing pile 32, which has been cut off from the ground G, by pulling it up by a predetermined length, and cutting and removing the same, large debris (concrete debris) generated during cutting is received by a debris fall prevention plate 40 and a net 46 arranged thereon, so that the debris is prevented from falling into an edge-cut hole 34. It is advantageous in smoothly performing the work of improving the muddy water in the hole 34 after removing the existing pile 32 to the same level as the surrounding ground G.SELECTED DRAWING: Figure 4

Description

The present invention relates to a method for removing an existing pile.

When rebuilding a building or structure, an existing pile may be located below the pillar of the new building or structure. In such a case, the existing pile is removed and a new pile is placed. ..
To remove the existing pile, first, the ground around the existing pile is excavated while supplying water, the existing pile and the ground are cut off, and then the existing pile is pulled out.
Then, after the existing piles are removed, the solidifying material is injected into the muddy water in the holes where the existing piles are buried so that the new piles are driven vertically, and the solidifying material is agitated and mixed by a stirrer to solidify the surroundings. Work will be done to improve it to the same level as the ground, after which new piles will be driven.
On the other hand, when the length of the existing pile is, for example, 30 m or 40 m, it cannot be transported by being placed on a truck or a trailer as it is.
Therefore, the work of pulling up and cutting the existing piles at predetermined lengths mounted on trucks, trailers, etc. is repeated.

Japanese Unexamined Patent Publication No. 2017-66721

However, such cutting work of the existing pile is performed by using a crusher or the like, and large debris (concrete debris) at the time of cutting falls into the edge-cut hole around the existing pile.
If large debris falls into the hole, it will hinder the stirring and mixing of the muddy water after pulling out the existing pile and the solidifying material, and it will not be possible to smoothly improve the muddy water in the hole to the same level as the surrounding ground. A problem occurs.
The present invention has been made in view of the above points, and an object of the present invention is to prevent debris from falling into a cut hole around an existing pile when cutting an existing pile, and to remove the existing pile. It provides a method for removing existing piles, which is advantageous for smoothly performing the work of improving the muddy water in the later hole to the same level as the surrounding ground.

In order to achieve the above-mentioned object, the present invention is a method for removing an existing pile that is cut and removed by pulling up an existing pile that has been cut off from the ground by a predetermined length, and around the existing pile. The base is placed on the ground, and the lifting wire is connected to the upper part of the existing pile, and the part of the existing pile located below the part to be cut of the existing pile is located above the base. The existing pile is pulled up so as to be used, one end of the hanging wire is connected to the existing pile located below the portion to be cut, and the other end of the hanging wire is connected to the base. On the base, a long groove extending in a width that allows the existing pile to move up and down and having one end open in the longitudinal direction thereof, and a wire insertion gap opened on the other end side of the long groove. The debris fall prevention plate to be held is placed in the long groove so that the existing pile can move up and down so that the portion to be cut of the existing pile is located above the debris fall prevention plate. The existing pile is placed through the lifting wire so that the hanging wire is positioned in the wire insertion gap and one end of the hanging wire is located below the debris fall prevention plate. The lifting wire and the hanging wire are brought into a tense state by the weight of the existing pile, a net is placed on the debris fall prevention plate around the existing pile, and the net is placed at the position to be cut. The existing pile is cut, the lifting wire is removed, the cut portion of the existing pile is removed and the net is removed, and after cutting, on the upper part of the existing pile suspended by the hanging wire. The removed lifting wire should be connected, the existing pile should be pulled up to the extent that the hanging wire is slack, the hanging wire should be removed, and the existing pile should be cut next to the existing pile. The existing pile is pulled up in the long groove so that the existing pile located below the location is located above the debris fall prevention plate, and the existing pile is located below the next cutting location. At the same time, one end of the removed hanging wire is connected to the base, and the other end of the hanging wire is connected to the base. The hanging wire is placed in a tense state due to the weight of the existing pile, a net is placed on the debris fall prevention plate around the existing pile, and the existing pile is cut at the next cutting point. The cut part of the existing pile It is characterized in that it is removed and such work is repeated.
Further, the present invention is a method for removing an existing pile in which an existing pile cut off from the ground is pulled up by a predetermined length, cut and removed, and a base is placed on the ground around the existing pile. One end of the lifting wire mounted and connected to the first winch is connected to the upper part of the existing pile, and the portion of the existing pile located below the portion to be cut of the existing pile is above the base. The existing pile is pulled up so as to be located at, one end of the first hanging wire is connected to the existing pile located below the portion to be cut, and the other end of the first hanging wire is connected to the above. Connected to the base, one end of the second hanging wire connected to the second winch is connected to the location of the existing pile located below the portion to be cut, and the top and bottom of the existing pile are placed on the base. A debris fall prevention plate having a long groove extending in a width that allows movement and having one end open in the longitudinal direction and a wire insertion gap opened on the other end side of the long groove is provided in the long groove. The existing piles are aligned and placed so that they can move up and down, and the existing piles are suspended so that the portion to be cut is located above the debris fall prevention plate and the first and second suspensions are made. The existing pile is placed via the lifting wire so that the wire is positioned in the wire insertion gap and one end of the first and second hanging wires is located below the debris fall prevention plate. The lifting wire and the first and second hanging wires are lowered to be in a tense state due to the weight of the existing pile, a net is placed on the debris fall prevention plate around the existing pile, and the cutting is performed. The existing pile is cut at a position to be taken, the lifting wire is removed, the cut portion of the existing pile is removed and the net is removed, and after cutting, the first and second hanging wires are used. The removed lifting wire is connected to the upper part of the existing suspended pile, and the existing pile is pulled up by the first winch to the extent that the first and second hanging wires are slackened, and then the first , One end of the second hanging wire is removed so that the portion of the existing pile located below the portion to be cut next to the existing pile by the lifting wire is located above the debris fall prevention plate. The existing pile is pulled up in the elongated groove, and one end of the removed first and second hanging wires is connected to the existing pile located below the portion to be cut next, and the first suspension is performed. The other end of the lowering wire is connected to the base, and thereafter, the existing pile is connected in the same manner as described above. The lifting wire and the first and second hanging wires are lowered to be in a tense state due to the weight of the existing pile, and a net is placed on the debris fall prevention plate around the existing pile. It is characterized in that the existing pile is cut at a portion to be cut, the cut portion of the existing pile is removed, and such an operation is repeated.
Further, in the present invention, the debris fall prevention plate has a main body plate portion having the long groove and the wire insertion gap, a closed position for closing the opened long groove portion, and an open position for opening the long groove portion. It is configured to include an opening / closing plate portion that is swingably connected to the main body plate portion between the two, and after the fall prevention plate is aligned and placed on the base, the opening / closing plate portion is opened. It is characterized by swinging from to the closed position.
Further, in the present invention, the edge of the existing pile with the ground is cut by rotationally driving the casing around the outer periphery of the existing pile by the rotary drive unit of the excavator, and the excavator is in the vertical direction of the rotary drive unit. The reader is provided, and the lower end of the reader is mounted on the base.
Further, the present invention is characterized in that the first winch is a winch provided by the excavator, and the second winch is a winch provided by a mobile crane different from the excavator.

According to the present invention, when an existing pile that has been cut off from the ground is pulled up by a predetermined length, cut and removed, large debris (concrete debris) generated during cutting is generated on the debris fall prevention plate and above. Since it is received by the net arranged in, debris is prevented from falling into the cut hole.
Therefore, it is advantageous in smoothly performing the work of improving the muddy water in the hole after removing the existing pile to the same level as the surrounding ground.
Further, according to the present invention, when cutting an existing pile, a simple configuration is required in which a hanging wire is used to support a portion of the existing pile located below the cut portion. It is advantageous for improving efficiency.
Further, according to the present invention, when the existing pile is cut, the existing pile below the cut portion can be reliably supported by both the first hanging wire and the second hanging wire, so that one wire is tentatively used. Since it is possible to prevent the existing pile from falling even if it is cut, it is advantageous in ensuring the safety of the work of removing the existing pile.
Further, according to the present invention, it is advantageous to smoothly route the hanging wire through the wire insertion gap of the debris fall prevention plate, and the opening / closing plate portion of the debris fall prevention plate is used as the closing position. Covering the open side of the long groove is advantageous in preventing the operator from falling into the long groove.
Further, according to the present invention, since the lower end of the leader of the excavator is mounted on the base, the base is stabilized when a load is applied to the base from an existing pile via a hanging wire. It is advantageous for installing on the ground.
Further, according to the present invention, since the second winch provided by the general-purpose mobile crane can be used in addition to the first winch provided by the excavator for removing the existing pile, it is troublesome to prepare a special heavy machine. This is advantageous in reducing the cost required for removing existing piles.

It is explanatory drawing of the removal method of the existing pile which concerns on 1st Embodiment, and shows the state which the existing pile and the ground are cut off. It is explanatory drawing of the removal method of the existing pile which concerns on 1st Embodiment, and shows the state which the existing pile was pulled up by a predetermined length through the lifting wire. It is explanatory drawing of the removal method of the existing pile which concerns on 1st Embodiment, and shows the state which the existing pile is connected to the base | base via the hanging wire. It is explanatory drawing of the method of removing the existing pile which concerns on 1st Embodiment, and shows the state in which the lifting wire and the hanging wire are in a tension state. It is explanatory drawing of the removal method of the existing pile which concerns on 1st Embodiment, and shows the state which the existing pile was cut, and the part of the cut existing pile was removed. It is explanatory drawing of the removal method of the existing pile which concerns on 1st Embodiment, and shows the state in which the lifting wire is connected to the part of the remaining existing pile. It is explanatory drawing of the removal method of the existing pile which concerns on 1st Embodiment, and shows the state in which the remaining existing pile is pulled up by a predetermined length through a lifting wire. It is explanatory drawing of the method of removing the existing pile which concerns on 1st Embodiment, (A) is the plan view of FIG. 1, (B) is the B arrow view of (A). It is explanatory drawing of the method of removing the existing pile which concerns on 1st Embodiment, (A) is the plan view of FIG. 2, (B) is the B arrow view of (A). It is explanatory drawing of the method of removing the existing pile which concerns on 1st Embodiment, (A) is the plan view of FIG. 3, (B) is the B arrow view of (A). It is a top view which made the opening and closing plate of the debris fall prevention plate open position. It is a side view of an excavator. It is explanatory drawing of the removal method of the existing pile which concerns on 2nd Embodiment, and shows the state which the existing pile and the ground are cut off. It is explanatory drawing of the removal method of the existing pile which concerns on 2nd Embodiment, and shows the state which the existing pile was pulled up by a predetermined length through the lifting wire. It is explanatory drawing of the removal method of the existing pile which concerns on 2nd Embodiment, and shows the state which the existing pile is connected to the base via the 1st and 2nd hanging wires. It is explanatory drawing of the method of removing the existing pile which concerns on 2nd Embodiment, and shows the state in which the lifting wire and the 1st and 2nd hanging wires are in a tension state. It is explanatory drawing of the removal method of the existing pile which concerns on 2nd Embodiment, and shows the state which the existing pile was cut, and the part of the cut existing pile was removed. It is explanatory drawing of the removal method of the existing pile which concerns on 2nd Embodiment, and shows the state in which the lifting wire is connected to the part of the remaining existing pile. It is explanatory drawing of the removal method of the existing pile which concerns on 2nd Embodiment, and shows the state in which the remaining existing pile is pulled up by a predetermined length through a lifting wire. It is a side view which shows an excavator and a part of a mobile crane.

(First Embodiment)
Hereinafter, a method for removing an existing pile according to an embodiment of the present invention will be described with reference to the drawings.
First, the edge cutting process of the existing pile from the ground, which is performed prior to the removal of the existing pile, will be described with reference to FIG.
An excavation device 10 is used in this edge cutting step, and the excavation device 10 includes a crane 12, a leader 14, a rotary drive unit 16, and a casing 18.
The crane 12 is undulating and expandable in the vertical direction on the lower traveling body 1204 provided with the crawler 1202, the upper rotating body 1206 provided on the upper part of the lower traveling body 1204 so as to be rotatable, and the upper rotating body 1206. It is equipped with a boom 1208 provided.

The leader 14 is swayably suspended via a leader bracket 15 supported at the tip of the boom 1208, and the lower end of the leader 14 is installed on a base 20 mounted on the ground around an existing pile. Will be done.
As shown in FIGS. 8A and 8B, the base 20 includes a lower girder member 22, an upper girder member 24, and a pile cradle 26.
The lower girder member 22 is composed of two wooden square timbers arranged in parallel at intervals so as to sandwich the existing pile.
The upper girder member 24 is composed of one wooden square timber placed so as to straddle the upper surface of one end of the lower girder member 22 in the longitudinal direction.
The pile cradle 26 has a U-shape having a base portion 26A extending in a straight line and a pair of side portions 26B and 26C extending in a direction orthogonal to the base portion 26A from both ends of the base portion 26A.
In the pile cradle 26, the upper girder member 24 and the base portion 26A are parallel to each other, and the base portion 26A and the pair of side portions 26B and 26C are positioned so as to sandwich the existing pile 32 and are placed on the upper surface of the lower girder member 22. ..
The pile cradle 26 is formed by joining steel materials such as H-shaped steel.
A hook 2602 for locking one end of the hanging wire 38, which will be described later, is provided inside one of the pair of side portions 26B and 26C.
As shown in FIG. 12, the first wire 28 and the second wire 30 are suspended from the upper end of the reader 14 via a pulley (not shown), and the first wire 28 and the second wire 30 are not shown. Each winch (winding device) independently winds and unwinds.

The rotation drive unit 16 is connected to the tip of the first wire 28, and is moved in the vertical direction along the reader 14 by winding and unwinding the first wire 28.
The casing 18 is configured by detachably connecting a plurality of casing divisions 1802 and is rotationally driven by a rotation driving unit 16, and the casing division 1802 located at the lowermost position has an excavation cutter 1804 at the lower end thereof. It is worn.

The edge cutting process of the existing pile 32 from the ground G is as follows.
As shown in FIG. 1, the ground G is excavated in advance so that the upper part of the existing pile 32 is exposed. Reference numeral 34 in the drawing indicates a cylindrical hole surrounding the outer peripheral surface of the existing pile 32 cut by the drilling device 10.
Next, the base 20 is installed around the existing pile 32, and the excavating device 10 is moved and installed in the vicinity of the existing pile 32.
The upper swing body 1206 of the crane 12 is swiveled and the boom 1208 is extended so that the casing 18 is located above the existing pile 32 and the axis of the casing 18 is aligned with the axis of the existing pile 32. ..
At this time, the lower end of the leader 14 is installed on the upper surface of the base 20 (upper pile member 24) so that the state in which the leader 14 extends in the vertical direction is maintained.
Next, while the casing 18 is rotated by the rotary drive unit 16, the first wire 28 of the crane 12 is unwound, so that the casing 18 excavates the ground G around the existing pile 32 while supplying water.
When the tip of the casing dividing body 1802 located at the lowest position reaches substantially the same position as the lower end of the existing pile 32, the first wire 28 of the crane 12 is wound up to rotate the casing 18 and pull it out from the ground G. ..
As a result, as shown in FIG. 1, the outer peripheral surface of the existing pile 32 and the ground G are cut off by the holes 34 over the entire length of the existing pile 32.

Next, a method of removing the existing pile 32 will be described.
When the existing pile 32 and the ground G are cut off, the casing 18 is disassembled and removed from the excavator 10.
As shown in FIGS. 1, 8 (A) and 8 (B), the base 20 remains placed on the ground G around the existing pile 32.
As shown in FIG. 1, the lifting wire 30A made of the second wire 30 is unwound from the crane 12 and one end thereof is wound around the outer peripheral surface of the upper part of the existing pile 32 exposed from the ground G to be connected.
In the figure, reference numeral X indicates a planned cutting location, which is a portion of the existing pile 32 to be cut.

Next, as shown in FIG. 2, the lifting wire 30A is wound up by the crane 12 and the existing pile 32 is raised so that the planned cutting position X is located at a position away from the base 20.
Then, as shown in FIGS. 9A and 9B, a plurality of (four in the present embodiment) wooden pieces are made parallel to each other at intervals in the direction orthogonal to the longitudinal direction of the upper girder member 24. The position adjusting member 36 made of square lumber is arranged on the upper girder member 24. The position adjusting member 36 is for adjusting the position of the debris fall prevention plate 40 in the height direction, which will be described later, and can be omitted if the position adjustment is unnecessary.
Further, as shown in FIG. 2, one end of the hanging wire 38 is pulled out above the base 20, and the other end is connected to the hook of the pile cradle 26.

Next, as shown in FIGS. 3 and 10, a debris fall prevention plate 40 is installed on the position adjusting member 36.
As shown in FIG. 11, the debris fall prevention plate 40 includes a main body plate portion 42 and an opening / closing plate portion 44.
The main body plate portion 42 and the opening / closing plate portion 44 may be made of steel plates, but if a lightweight material such as a metal material having a mesh shape such as expansion metal is used, the installation work may be performed. It is advantageous for improving efficiency.
The main body plate portion 42 has a plate shape having a rectangular contour that is one size larger than the contour of the base 20.
The main body plate portion 42 extends toward the elongated groove 4202 provided on the other end side of the elongated groove 4202 and extending at a width that allows the existing pile 32 to move up and down and having one end opened in the longitudinal direction thereof. It has a missing portion 4204 for inserting a wire.
The opening / closing plate portion 44 is connected to a portion of one of the two side portions of the main body plate portion 42 parallel to the extending direction of the long groove 4202 toward the open side of the long groove 4202 via a hinge (not shown). ing.
As shown in FIGS. 3 and 10, the opening / closing plate portion 44 is overlapped with the upper surface of the main body plate portion 42 and covers one end of the elongated groove 4202, and is separated from the main body plate portion 42 as shown in FIG. It swings with the open position.

The debris fall prevention plate 40 is installed as follows.
With the opening / closing plate 44 in the open position, the debris fall prevention plate 40 is held in a horizontal state, and the debris fall prevention plate 40 is moved so that the existing pile 32 enters the long groove 4202 from one end of the long groove 4202. The debris fall prevention plate 40 allows the existing pile 32 to rise in the long groove 4202, one end of the long groove 4202 faces the leader 14, and the four sides of the debris fall prevention plate 40 (main body plate 42) are the base 26A. It is positioned on the upper surface of the position adjusting member 36 so as to be parallel to the pair of side portions 26B and 26C, respectively.
When the debris fall prevention plate 40 is installed on the upper surface of the position adjusting member 36, the opening / closing plate portion 44 is set as the closing position to cover the open side of the long groove 4202. As a result, when an operator enters the debris fall prevention plate 40, the operator is prevented from falling into the long groove 4202.
Further, as shown in FIG. 3, one end of the hanging wire 38 is pulled out above the debris fall prevention plate 40 via the wire insertion missing portion 4204, and the existing pile 32 located below the planned cutting portion X. Wrap it around the outer peripheral surface and connect it. By providing the wire insertion missing portion 4204, the hanging wire 38 does not interfere with the debris fall prevention plate 40, which is advantageous in smoothly handling the hanging wire 38.

Next, as shown in FIG. 4, the planned cutting portion X of the existing pile 32 is positioned above the debris fall prevention plate 40, and the hanging wire 38 is positioned in the wire insertion missing portion 4204. The existing pile 32 is lowered via the lifting wire 30A so that one end of the hanging wire 38 is located below the debris fall prevention plate 40.
Then, the lifting wire 30A and the hanging wire 38 are placed in a tense state due to the weight of the existing pile 32, and the net 46 is arranged on the debris fall prevention plate 40 around the existing pile 32.

Next, as shown in FIG. 5, the existing pile 32 is cut at the planned cutting location X. When cutting the existing pile 32, various conventionally known devices such as a crusher and a breaker can be used.
Due to this cutting, large debris (concrete debris) falls around the existing pile 32,
Since it is received by the debris fall prevention plate 40 and the net 46 arranged on the debris fall prevention plate 40, it is prevented that the debris falls into the edge-cut hole 34.
When the existing pile 32 is cut, the existing pile 32 below the cut portion is supported by the base 20 via the hanging wire 38, so that the existing pile 32 does not fall.

Then, the suspension wire 38 is wound up by the crane 12 to raise and remove the cut portion of the existing pile 32. The hanging wire 38 is removed from the portion of the existing pile 32 that has been removed.
Then, the net 46 is removed from the debris fall prevention plate 40 together with the debris.

Next, as shown in FIG. 6, after cutting, the lifting wire 30A removed is connected to the upper part of the existing pile 32 suspended by the hanging wire 38, and the crane is slackened to the extent that the hanging wire 38 is slackened. After pulling up the existing pile 32 by 12, one end of the hanging wire 38 is removed from the existing pile 32. At this time, the other end of the hanging wire 38 may be removed from the hook 2602 of the base 20 if necessary.

Next, as shown in FIG. 7, by hoisting the lifting wire 30A with the crane 12, the portion of the existing pile 32 located below the planned cutting portion X, which is the portion to be cut next to the existing pile 32, falls. The existing pile 32 is pulled up in the elongated groove 4202 so as to be located above the prevention plate 40.
Then, one end of the removed hanging wire 38 is connected to the existing pile 32 located below the portion to be cut next. If the other end of the hanging wire 38 has been removed from the hook 2602 of the base 20, the other end of the hanging wire 38 is connected to the hook 2602 again.

After that, similarly, as shown in FIGS. 4 and 5, the existing pile 32 is lowered, the lifting wire 30A and the hanging wire 38 are put into a tense state by the weight of the existing pile 32, and around the existing pile 32. The net 46 is arranged on the debris fall prevention plate 40, and the existing pile 32 is cut at a position to be cut next to remove the cut portion of the existing pile 32.
Such work is repeated until all the existing piles 32 are removed.

According to the present embodiment, when the existing pile 32 cut off from the ground G is pulled up by a predetermined length, cut and removed, large debris (concrete debris) generated at the time of cutting is prevented from falling. Since it is received by the plate 40 and the net 46 arranged on the plate 40, debris is prevented from falling into the edge-cut hole 34.
Therefore, it is advantageous in smoothly performing the work of improving the muddy water in the hole 34 after removing the existing pile 32 to the same level as the surrounding ground G.
Further, in the present embodiment, since the simple configuration of supporting the portion of the existing pile 32 located below the cut portion by using the hanging wire 38 is sufficient, the efficiency of the removal work of the existing pile 32 is improved. It will be advantageous on.

Further, according to the present embodiment, since the lower end of the leader 14 of the excavating device 10 is mounted on the base 20, a load is applied to the base 20 from the existing pile 32 via the hanging wire 38. In this case, it is advantageous for the base 20 to be stably installed on the ground G.

(Second Embodiment)
Next, the second embodiment will be described with reference to FIGS. 8 to 11 and FIGS. 13 to 20.
In the following embodiments, the same parts and members as those in the first embodiment are designated by the same reference numerals as those in the first embodiment, and the description thereof will be omitted.
In the first embodiment, a case where the existing pile 32 is pulled up by using the crane 12 of the excavating device 10 has been described.
On the other hand, in the second embodiment, as shown in FIG. 20, a mobile crane 48 is prepared separately from the excavating device 10, and the wire 50 of the mobile crane 48 is used as the lifting wire 50A. The point that the pile 32 is pulled up is different from the first embodiment.
Further, in the second embodiment, the existing pile 32 below the planned cutting portion X is connected to the suspension wire 38 (hereinafter referred to as the first suspension wire 38) connected to the base 20. It differs from the first embodiment in that it is supported by two hanging wires 38 and 52 with a second hanging wire 52 that is wound up and unwound by the crane 12 of the excavating device 10 of the excavating device 10. .. The second hanging wire 52 corresponds to the lifting wire 30A in the first embodiment, but will be described as the second hanging wire 52 for convenience of explanation.

Similar to the first embodiment, as shown in FIGS. 13, 8 (A) and 8 (B), the base 20 is placed on the ground G around the existing pile 32, and the leader of the excavator 10 The lower end of 14 is installed on the base 20.
In addition, a mobile crane 48 is installed on the ground G near the existing pile 32. The mobile crane 48 includes a first winch (not shown) for hoisting and unwinding the lifting wire 50A.
As the mobile crane 48, various conventionally known general-purpose mobile cranes such as a rough terrain crane can be used.
On the other hand, the crane 12 of the excavator 10 includes a second winch (not shown) for hoisting and unwinding the second hanging wire 52, which will be described later.

As shown in FIG. 13, the lifting wire 50A is unwound from the mobile crane 48 (first winch), and one end of the lifting wire 50A is wound around the outer peripheral surface of the upper portion of the existing pile 32 exposed from the ground G to be connected.

Next, as shown in FIG. 14, the lifting wire 50A is wound up by the mobile crane 48 (first winch), and the existing pile 32 is placed so that the planned cutting point X is located at a position away from the base 20. Raise it.
Then, as shown in FIGS. 9A, 9B, and 14, the position adjusting member 36 is arranged on the upper girder member 24.
Further, as shown in FIG. 14, one end of the first hanging wire 38 is pulled out above the base 20, and the other end is connected to the hook 2602 of the pile cradle 26.

Next, as shown in FIGS. 15 and 10, as in the first embodiment, the debris fall prevention plate 40 is installed on the position adjusting member 36, and the opening / closing plate portion 44 is set as the closing position of the long groove 4202. Cover the open side.
Further, as shown in FIG. 15, one end of the first hanging wire 38 is pulled out above the debris fall prevention plate 40 via the wire insertion missing portion 4204, and the existing pile located below the planned cutting portion X. It is wound around the outer peripheral surface of 32 and connected.
Further, one end of the second hanging wire 52 of the crane 12 of the excavating device 10 is wound around and connected to the outer periphery of the existing pile 32 separated above one end of the first hanging wire 38. At this time, one end of the second hanging wire 52 is positioned on the existing pile 32 so that the second hanging wire 52 extending vertically in a plan view is located in the wire insertion missing portion 4204. Link. At this time, the second hanging wire 52 is in a slack state.

Next, as shown in FIG. 16, the first hanging wire 38 and the second hanging wire 52 are arranged so that the planned cutting portion X of the existing crane 32 is located above the debris fall prevention plate 40. The existing crane 32 is movable so that one end of the first hanging wire 38 and one end of the second hanging wire 52 are located below the debris fall prevention plate 40 so as to be located in the wire insertion gap 4204. It is lowered via the lifting wire 50A of the crane 48.
Then, the lifting wire 50A, the first hanging wire 38, and the second hanging wire 52 are placed in a tense state due to the weight of the existing pile 32. At this time, the amount of hoisting of the second hanging wire 52 by the crane 12 (second winch) of the excavating device 10 so that both the first hanging wire 38 and the second hanging wire 52 are in a tense state. Alternatively, the amount of feeding is adjusted.
Next, the net 46 is arranged on the debris fall prevention plate 40 around the existing pile 32.

Next, as shown in FIG. 17, the existing pile 32 is cut at the planned cutting location X.
Due to this cutting, large debris (concrete debris) falls around the existing pile 32,
Since it is received by the debris fall prevention plate 40 and the net 46 arranged on the debris fall prevention plate 40, it is prevented that the debris falls into the edge-cut hole 34.
When the existing pile 32 is cut, the existing pile 32 below the cut portion is supported by the base 20 via the first hanging wire 38 and via the second hanging wire 52. Since it is supported by the crane 12 of the excavator 10, it does not fall.

Then, the lifting wire 50A is wound up by the mobile crane 48 (first winch), and the cut portion of the existing pile 32 is lifted and removed. The lifting wire 50A is removed from the removed portion of the existing pile 32.
Then, the net 46 is removed from the debris fall prevention plate 40 together with the debris.

Next, as shown in FIG. 18, after cutting, the removed lifting wire 50A is connected to the upper part of the existing pile 32 suspended by the first and second suspending wires 38 and 52, and the first and second suspending wires 38 and 52 are connected. After pulling up the existing pile 32 with the mobile crane 48 (first winch) to the extent that the second hanging wires 38 and 52 slacken, one end of the first and second hanging wires 38 and 52 is pulled from the existing pile 32. Remove. At this time, the other end of the first hanging wire 38 may be removed from the hook 2602 of the base 20 if necessary.

Next, as shown in FIG. 19, the existing pile 32 is located below the planned cutting portion X, which is the portion to be cut next to the existing pile 32 by hoisting the lifting wire 50A by the mobile crane 48 (first winch). The existing pile 32 is pulled up in the long groove 4202 so that the portion of the pile 32 is located above the debris fall prevention plate 40.
Then, one end of the removed first hanging wire 38 is connected to the existing pile 32 located below the place to be cut next, and the one end is above the one end of the first hanging wire 38. One end of the second hanging wire 52 is connected to the existing pile 32. If the other end of the first hanging wire 38 has been removed from the hook 2602 of the base 20, the other end of the first hanging wire 38 is connected to the hook 2602 again.

After that, similarly, as shown in FIGS. 16 and 17, the existing pile 32 is lowered, and the lifting wire 50A, the first hanging wire 38, and the second hanging wire 52 are brought together by the weight of the existing pile 32. In a tense state, the net 46 is placed on the debris fall prevention plate 40 around the existing pile 32, and then the existing pile 32 is cut at a position to be cut and the cut portion of the existing pile 32 is removed.
Such work is repeated until all the existing piles 32 are removed.

According to the second embodiment, it goes without saying that the same effect as that of the first embodiment is obtained, and the cut portion is formed by both the first hanging wire 38 and the second hanging wire 52. The load of the existing pile 32 below is supported.
Therefore, when the existing pile 32 is cut, the existing pile 32 below the cut portion can be reliably supported by the two wires, and even if one of the wires is cut, the existing pile 32 can be prevented from falling. This is advantageous in ensuring the safety of the removal work of the pile 32.

Further, according to the second embodiment, the winch provided by the excavating device 10 is used as the first winch, and the winch provided by the mobile crane 48 different from the excavating device 10 is used as the second winch.
Therefore, since the second winch provided in the general-purpose mobile crane 48 can be used in addition to the first winch of the excavator 10 for removing the existing pile 32, it is not necessary to prepare a special heavy machine. This is advantageous in reducing the cost required for the removal work of the existing pile 32.

10 Excavator 12 Crane 1202 Crawler 1204 Lower traveling body 1206 Upper traveling body 1208 Boom 14 Leader 15 Leader bracket 16 Rotating drive 18 Casing 1802 Casing split 1804 Cutter 20 Base 22 Lower girder 24 Upper girder 26 Pile cradle 26A Base 26B, 26C Side 2602 Hook 28 1st wire 30 2nd wire 30A Lifting wire 32 Existing pile 34 Hole 36 Position adjusting member 38 Hanging wire (1st hanging wire)
40 Debris fall prevention plate 42 Main body plate 4202 Long groove 4204 Missing part for wire insertion 44 Opening and closing plate 46 Net 48 Mobile crane 50 Wire 50A Lifting wire 52 Second hanging wire

Claims (5)

It is a method of removing existing piles that are cut and removed by pulling up existing piles that are cut off from the ground by a predetermined length.
Place the base on the ground around the existing pile,
The lifting wire is connected to the upper part of the existing pile, and the existing pile is pulled up so that the portion of the existing pile located below the portion to be cut of the existing pile is located above the base.
One end of the hanging wire is connected to the existing pile located below the portion to be cut, and the other end of the hanging wire is connected to the base.
The base has a long groove extending in a width that allows the existing pile to move up and down and having one end open in the longitudinal direction thereof, and a wire insertion gap opened on the other end side of the long groove. The debris fall prevention plate is placed in the long groove so that the existing pile can move up and down.
The portion of the existing pile to be cut is located above the debris fall prevention plate, and the hanging wire is positioned in the wire insertion gap so that one end of the hanging wire is said. The existing pile is lowered via the lifting wire so as to be located below the debris fall prevention plate.
The lifting wire and the hanging wire are placed in a tense state due to the weight of the existing pile.
A net is placed on the debris fall prevention plate around the existing pile.
The existing pile is cut at the portion to be cut, the lifting wire is removed, the cut portion of the existing pile is removed, and the net is removed.
After cutting, the removed lifting wire is connected to the upper part of the existing pile suspended by the hanging wire, and the existing pile is pulled up to the extent that the hanging wire is slack, and then the hanging wire is used. Remove the wire,
The existing pile is pulled up in the long groove so that the portion of the existing pile located below the portion to be cut next to the existing pile is located above the debris fall prevention plate by the lifting wire.
One end of the removed hanging wire is connected to the existing pile located below the next cutting point, and the other end of the hanging wire is connected to the base.
After that, in the same manner as described above, the existing pile is lowered, the lifting wire and the hanging wire are put into a tension state by the weight of the existing pile, and a net is placed on the debris fall prevention plate around the existing pile. Is placed, the existing pile is cut at the point to be cut next, and the cut portion of the existing pile is removed.
Repeat this kind of work,
A method of removing existing piles, which is characterized by this. It is a method of removing existing piles that are cut and removed by pulling up existing piles that are cut off from the ground by a predetermined length.
Place the base on the ground around the existing pile,
One end of the lifting wire connected to the first winch is connected to the upper part of the existing pile so that the portion of the existing pile located below the portion to be cut of the existing pile is located above the base. Pull up the existing pile to
One end of the first hanging wire is connected to the existing pile located below the portion to be cut, and the other end of the first hanging wire is connected to the base.
One end of the second hanging wire connected to the second winch is connected to the existing pile located below the portion to be cut.
The base has a long groove extending in a width that allows the existing pile to move up and down and having one end open in the longitudinal direction thereof, and a wire insertion gap opened on the other end side of the long groove. The debris fall prevention plate is placed in the long groove so that the existing pile can move up and down.
The first and second hanging wires are positioned in the wire insertion gaps so that the portion of the existing pile to be cut is located above the debris fall prevention plate. (2) The existing pile is lowered via the lifting wire so that one end of the hanging wire is located below the debris fall prevention plate.
The lifting wire and the first and second hanging wires are placed in a tense state due to the weight of the existing pile.
A net is placed on the debris fall prevention plate around the existing pile.
The existing pile is cut at the portion to be cut, the lifting wire is removed, the cut portion of the existing pile is removed, and the net is removed.
After cutting, the removed lifting wire is connected to the upper part of the existing pile suspended by the first and second hanging wires, and the first and second hanging wires are slackened to the extent that the first and second hanging wires are slackened. After pulling up the existing pile with one winch, one end of the first and second hanging wires is removed.
The existing pile is pulled up in the long groove so that the portion of the existing pile located below the portion to be cut next to the existing pile is located above the debris fall prevention plate by the lifting wire.
One end of the removed first and second hanging wires is connected to the existing pile located below the place to be cut next, and the other end of the first hanging wire is connected to the base. Connected to
After that, in the same manner as described above, the existing pile is lowered, the lifting wire and the first and second hanging wires are put into a tension state by the weight of the existing pile, and the debris falls around the existing pile. A net is placed on the prevention plate, the existing pile is cut at the point to be cut next, and the cut portion of the existing pile is removed.
Repeat this kind of work,
A method of removing existing piles, which is characterized by this. The debris fall prevention plate is formed between a main body plate portion having the long groove and the wire insertion gap, and a closed position for closing the opened long groove portion and an open position for opening the long groove portion. It is configured to include an opening / closing plate part that is swingably connected to the part.
After the fall prevention plate is aligned and placed on the base, the opening / closing plate portion is swung from the open position to the closed position.
The method for removing an existing pile according to claim 1 or 2, wherein the existing pile is removed. The edge of the existing pile with the ground is cut off by rotationally driving the casing around the outer circumference of the existing pile by a rotary drive unit of an excavator.
The excavator includes a reader that guides the rotary drive unit in the vertical direction.
The lower end of the reader is placed on the base,
The method for removing an existing pile according to any one of claims 1 to 3, wherein the existing pile is removed. The first winch is a winch included in the excavator.
The second winch is a winch provided by a mobile crane different from the excavator.
The method for removing an existing pile according to claim 4, wherein claim 2 is cited.

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