JP7438006B2 - How to remove existing piles - Google Patents

Description

The present invention relates to a method for removing existing piles.

When rebuilding a building or structure, existing piles may be located below the pillars of the new building or structure, and in such cases, the existing piles are removed and new piles are driven. .
To remove existing piles, first, the ground around the existing piles is excavated while water is supplied, the existing piles are separated from the ground, and then the existing piles are pulled out.
After the existing pile is removed, a solidifying agent is injected into the muddy water in the hole where the existing pile was buried, and is stirred and mixed using a stirring device to solidify so that the new pile will be driven vertically. Work will be carried out to improve the soil to the same level as the ground, and then new piles will be driven.
On the other hand, if the length of the existing pile is, for example, 30 m or 40 m, it cannot be transported as is on a truck or trailer.
Therefore, the existing piles are repeatedly pulled up and cut to a predetermined length to be mounted on a truck or trailer.

JP2017-66721A

However, such cutting work of existing piles is performed using a crusher or the like, and large debris (concrete fragments) from the cutting fall into holes cut around the existing piles.
If large debris falls into the hole, it will interfere with stirring and mixing the muddy water and solidification material after the existing piles have been pulled out, making it impossible to smoothly improve the muddy water in the hole to the same level as the surrounding ground. A problem occurs.
This invention was made in view of the above points, and an object of the present invention is to prevent debris from falling into a hole cut around the existing pile when cutting the existing pile, and to remove the existing pile. This provides an advantageous method for removing existing piles in order to smoothly improve the muddy water in the hole to the same level as the surrounding ground.

In order to achieve the above-mentioned object, the present invention provides a method for removing an existing pile that is separated from the ground by pulling it up every predetermined length, cutting it, and removing it, the method comprising: A base is placed on the ground, and a lifting wire is connected to the top of the existing pile so that the part of the existing pile that is located below the part of the existing pile to be cut is located above the base. Pull up the existing pile so as to connect one end of the hanging wire to the part of the existing pile located below the point to be cut, and connect the other end of the hanging wire to the base. , on the base, a long groove extending with a width that allows vertical movement of the existing pile and having one longitudinal end open, and a notch for wire insertion that is open at the other end of the long groove; A rubble fall prevention plate having a structure is positioned and placed so that the existing pile can move up and down within the long groove, and the part of the existing pile to be cut is positioned above the rubble fall prevention plate. , and the existing pile is placed through the lifting wire such that the hanging wire is located in the wire insertion notch and the one end of the hanging wire is located below the debris fall prevention plate. The lifting wire and the hanging wire are brought into tension 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 on the debris fall prevention plate at the point where the cutting is to be performed. Cut the existing pile, remove the lifting wire, remove the cut portion of the existing pile and remove the net, and after cutting, attach the wire to the top of the existing pile suspended by the hanging wire. After connecting the removed lifting wire and pulling up the existing pile to the extent that the hanging wire becomes slack, the hanging wire should be removed and the lifting wire should be cut next to the existing pile. Pull up the existing pile in the long groove so that the part of the existing pile located below the spot is located above the rubble fall prevention plate, and the part of the existing pile located below the part to be cut next. Connect one end of the removed hanging wire to the base, and connect the other end of the hanging wire to the base. Thereafter, in the same manner as above, lower the existing pile and connect it to the lifting wire. The hanging wire is put under tension by 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 point to be cut. The method is characterized in that the cut portion of the existing pile is removed and such work is repeated.
The present invention also provides a method for removing existing piles, in which existing piles that have been cut off from the ground are pulled up and removed at predetermined lengths, and a base is placed on the ground around the existing piles. one end of the lifting wire connected to the first winch is connected to the upper part of the existing pile so that the part of the existing pile located below the part of the existing pile to be cut is placed above the base. , and connect one end of the first suspension wire to the location of the existing stake located below the location to be cut, and connect the other end of the first suspension wire to the location of the existing stake located below the location to be cut. One end of the second hanging wire connected to the second winch is connected to the base and is located below the point to be cut. A debris fall prevention plate having a long groove that extends with a width that allows movement and is open at one end in the longitudinal direction, and a cutout for wire insertion that is open at the other end of the long groove, is installed in the long groove. The existing pile is aligned and placed so that it can move up and down, and the first and second suspensions are placed so that the part of the existing pile to be cut is located above the debris fall prevention plate. the existing pile through the lifting wire so that the one ends of the first and second hanging wires are located below the debris fall prevention plate. The lifting wire and the first and second hanging wires are brought into tension by 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. Cut the existing pile at the desired location, remove the lifting wire, remove the cut portion of the existing pile and remove the net, and after cutting, use the first and second hanging wires. After connecting the removed lifting wire to the upper part of the suspended existing pile and pulling up the existing pile with the first winch to the extent that the first and second hanging wires become slack, , remove one end of the second hanging wire, and use the lifting wire to position the part of the existing pile located below the part of the existing pile to be cut next to be located above the debris fall prevention plate. Pull up the existing pile in the long groove, connect one end of the removed first and second hanging wires to a part of the existing pile located below the part to be cut next, and The other end of the hanging wire is connected to the base, and thereafter, the existing pile is lowered in the same manner as described above, and the lifting wire and the first and second hanging wires are connected to the existing pile under its own weight. placing a net on the debris fall prevention plate around the existing pile, cutting the existing pile at the next point to be cut, and removing the cut portion of the existing pile; It is characterized by repeatedly performing such operations.
Further, in the present invention, the debris fall prevention plate has a main body plate portion having the long groove and the wire insertion cutout, a closed position where the opened long groove portion is closed, and an open position where the long groove portion is opened. and an opening/closing plate part swingably connected to the main body plate part, and after aligning and placing the fall prevention plate on the base, the opening/closing plate part is moved to the open position. It is characterized by being made to swing from the position to the closed position.
Further, in the present invention, the edge of the existing pile is separated from the ground by rotationally driving a casing on the outer periphery of the existing pile by a rotation drive unit of an excavation device, and the excavation device is moved in the vertical direction of the rotation drive unit. The device is characterized in that the device includes a leader for guiding the device, and a lower end of the leader is placed on the base.
Further, the present invention is characterized in that the first winch is a winch included in the excavation rig, and the second winch is a winch included in a mobile crane different from the excavation rig.

According to the present invention, when an existing pile that has been cut off from the ground is pulled up, cut, and removed at predetermined lengths, large debris (concrete fragments) generated during cutting are removed from the debris fall prevention plate and the top of the pile. This prevents debris from falling into the edged hole.
Therefore, it is advantageous to smoothly improve the muddy water in the hole after removing the existing pile to the same level as the surrounding ground.
Furthermore, according to the present invention, when cutting an existing pile, it is sufficient to use a hanging wire to support the part of the existing pile located below the cutting point, which makes it easier to remove the existing pile. This is advantageous for improving efficiency.
Further, according to the present invention, when an existing pile is cut, the existing pile below the cut point can be reliably supported by both the first hanging wire and the second hanging wire, so even if one wire is Even if the existing piles are cut, falling of the existing piles can be avoided, which is advantageous in ensuring the safety of the existing pile removal work.
Further, according to the present invention, it is advantageous to smoothly route the hanging wire through the wire insertion cutout of the debris fall prevention plate, and the opening/closing plate portion of the debris fall prevention plate can be set at the closed position. Covering the open side of the long groove is advantageous in preventing workers from falling into the long groove.
Further, according to the present invention, since the lower end of the leader of the drilling equipment is placed on the base, the base is stabilized when a load is applied to the base from the existing pile via the hanging wire. This is advantageous when installing on the ground.
Furthermore, according to the present invention, in addition to the first winch provided on the excavation equipment that removes existing piles, the second winch provided on a general-purpose mobile crane can be used, thereby eliminating the need to prepare special heavy equipment. This is advantageous in reducing the cost required for removing existing piles.

It is an explanatory view of the method of removing an existing pile according to the first embodiment, and shows a state where the existing pile and the ground are separated. FIG. 2 is an explanatory diagram of the method for removing an existing pile according to the first embodiment, and shows a state in which the existing pile has been pulled up by a predetermined length via a lifting wire. FIG. 2 is an explanatory diagram of a method for removing an existing pile according to the first embodiment, and shows a state in which the existing pile is connected to a base via a hanging wire. It is an explanatory view of the method of removing an existing pile according to the first embodiment, and shows a state in which the lifting wire and the hanging wire are in a tensioned state. FIG. 2 is an explanatory diagram of the method for removing an existing pile according to the first embodiment, showing a state in which the existing pile has been cut and the cut portion of the existing pile has been removed. FIG. 2 is an explanatory diagram of the method for removing an existing pile according to the first embodiment, and shows a state in which a lifting wire is connected to the remaining portion of the existing pile. FIG. 2 is an explanatory diagram of the existing pile removal method according to the first embodiment, showing a state in which the remaining existing pile has been pulled up by a predetermined length via a lifting wire. FIG. 2 is an explanatory diagram of a method for removing an existing pile according to the first embodiment, in which (A) is a plan view of FIG. 1 and (B) is a view taken in the direction of arrow B in (A). FIG. 3 is an explanatory diagram of a method for removing an existing pile according to the first embodiment, in which (A) is a plan view of FIG. 2 and (B) is a view taken in the direction of arrow B in (A). FIG. 4 is an explanatory diagram of a method for removing an existing pile according to the first embodiment, in which (A) is a plan view of FIG. 3 and (B) is a view taken in the direction of arrow B in (A). FIG. 3 is a plan view with the opening/closing plate of the debris fall prevention plate in the open position. FIG. 2 is a side view of the drilling rig. It is an explanatory view of the method of removing an existing pile according to the second embodiment, and shows a state in which the existing pile and the ground are separated. It is an explanatory view of a method of removing an existing pile according to the second embodiment, and shows a state in which the existing pile has been pulled up by a predetermined length via a lifting wire. It is an explanatory view of the removal method of the existing pile concerning a 2nd embodiment, and shows the state where the existing pile was connected to the base via the 1st and 2nd suspension wire. It is an explanatory view of the method of removing an existing pile according to the second embodiment, and shows a state in which the lifting wire and the first and second hanging wires are in a tensioned state. It is an explanatory view of the method of removing an existing pile according to the second embodiment, and shows a state in which the existing pile has been cut and the cut portion of the existing pile has been removed. It is an explanatory view of the method of removing an existing pile according to the second embodiment, and shows a state in which a lifting wire is connected to a portion of the existing pile that remains. It is an explanatory view of the existing pile removal method concerning a 2nd embodiment, and shows the state where the remaining existing pile has been pulled up by a predetermined length via the lifting wire. It is a side view showing an excavation rig and a part of a mobile crane.

(First embodiment)
Hereinafter, a method for removing existing piles according to an embodiment of the present invention will be described with reference to the drawings.
First, the process of cutting the edge of the existing pile from the ground, which is performed prior to removing the existing pile, will be described with reference to FIG. 12.
In this edge cutting step, an excavation device 10 is used, and the excavation device 10 includes a crane 12, a leader 14, a rotation drive unit 16, and a casing 18.
The crane 12 includes a lower traveling body 1204 provided with a crawler 1202, an upper rotating body 1206 that is rotatably provided on the upper part of the lower traveling body 1204, and an upper rotating body 1206 that is movable in the vertical direction and extendable. A boom 1208 is provided.

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

The rotation drive unit 16 is connected to the tip of the first wire 28, and is moved in the vertical direction along the leader 14 by winding and unwinding the first wire 28.
The casing 18 is composed of a plurality of casing division bodies 1802 that are detachably connected, and is rotationally driven by the rotary drive unit 16. The lowest casing division body 1802 has a cutting cutter 1804 attached to its lower end. It is worn.

The process of cutting the edge 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. In addition, the code|symbol 34 in the figure shows the cylindrical hole which surrounds the outer peripheral surface of the existing pile 32 edge-cut by the excavation device 10.
Next, the base 20 is installed around the existing pile 32, and the excavation device 10 is moved and installed near the existing pile 32.
The upper revolving body 1206 of the crane 12 is rotated and the boom 1208 is extended to position the casing 18 so that it is located above the existing pile 32 and the axis of the casing 18 coincides 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 material 24) so that the leader 14 is maintained in a vertically extending state.
Next, while rotating the casing 18 by the rotary drive unit 16, the first wire 28 of the crane 12 is let out, thereby excavating the ground G around the existing pile 32 with the casing 18 while supplying water.
When the tip of the lowermost casing segment 1802 reaches approximately 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 remove it 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 separated by the hole 34 over the entire length of the existing pile 32.

Next, a method for removing the existing pile 32 will be explained.
Once the existing pile 32 and the ground G have been separated, the casing 18 is disassembled and removed from the excavation device 10.
Note that, as shown in FIGS. 1, 8(A), and 8(B), the base 20 remains placed on the ground G around the existing piles 32.
As shown in FIG. 1, a lifting wire 30A consisting of a second wire 30 is paid out from the crane 12, and one end of the lifting wire 30A is wound around and connected to the upper outer peripheral surface of an existing pile 32 exposed from the ground G.
In addition, in the figure, the code|symbol X shows the cut planned location which is the location where the existing pile 32 should be cut.

Next, as shown in FIG. 2, the lifting wire 30A is hoisted up by the crane 12, and the existing pile 32 is raised so that the planned cutting location X is located upwardly away from the base 20.
As shown in FIGS. 9A and 9B, a plurality of (four in this embodiment) wooden blocks are arranged parallel to each other at intervals in a direction orthogonal to the longitudinal direction of the upper beam member 24. Position adjustment members 36 made of square timbers are arranged on the pile support 26 . The position adjustment member 36 is for adjusting the position in the height direction of the debris fall prevention plate 40, which will be described later, and can be omitted if position adjustment is not required.
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 holder 26.

Next, as shown in FIGS. 3 and 10, a debris fall prevention plate 40 is installed on the position adjustment member 36.
As shown in FIG. 11, the debris fall prevention plate 40 includes a main body plate part 42 and an opening/closing plate part 44.
The main body plate part 42 and the opening/closing plate part 44 may be made of steel plates, but if a lightweight material such as a mesh-shaped metal material such as expansion metal is used, the installation work will be easier. This is advantageous for improving efficiency.
The main body plate portion 42 has a plate shape with a rectangular outline that is one size larger than the outline of the base 20 .
The main body plate part 42 has a long groove 4202 that extends with a width that allows vertical movement of the existing pile 32 and is open at one end in the longitudinal direction, and a long groove 4202 that is provided at the other end of the long groove 4202 and is open toward the long groove 4202. It has a cutout 4204 for wire insertion.
The opening/closing plate portion 44 is connected via a hinge (not shown) to a location near the open side of the long groove 4202 on one side of the two sides of the main body plate portion 42 parallel to the extending direction of the long groove 4202. ing.
As shown in FIGS. 3 and 10, the opening/closing plate 44 can be placed in a closed position where it overlaps the top surface of the main body plate 42 and covers one end of the long groove 4202, or in a closed position where it is separated from the main body plate 42, as shown in FIG. It swings between the open position and the open position.

The debris fall prevention plate 40 is installed as follows.
After holding the debris fall prevention plate 40 in a horizontal state with the opening/closing plate part 44 in the open position, and moving the debris fall prevention plate 40 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 is arranged so that the existing pile 32 can rise within 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 part 42) are arranged at the base 26A, It is aligned so as to be parallel to the pair of side portions 26B and 26C, respectively, and placed on the upper surface of the position adjustment member 36.
Once the debris fall prevention plate 40 is installed on the upper surface of the position adjustment member 36, the open side of the long groove 4202 is covered with the opening/closing plate part 44 in the closed position. This prevents the worker from falling into the long groove 4202 when the worker steps onto the debris fall prevention plate 40.
Further, as shown in FIG. 3, one end of the hanging wire 38 is pulled out above the debris fall prevention plate 40 through the wire insertion notch 4204, and the existing pile 32 located below the planned cutting location Wrap it around the outer circumferential surface and connect it. By providing the wire insertion cutout 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 hanging wire 38 is positioned in the notch 4204 for wire insertion so that the cut point X of the existing pile 32 is located above the debris fall prevention plate 40. Then, 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 brought into tension by the weight of the existing pile 32, and a net 46 is placed 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 fragments) falls around the existing pile 32, but
Since the debris is caught by the debris fall prevention plate 40 and the net 46 placed thereon, debris is prevented from falling into the edged hole 34.
Note that when the existing pile 32 is cut, the existing pile 32 below the cut point is supported by the base 20 via the hanging wire 38, so that it does not fall.

Then, the crane 12 hoists the lifting wire 30A to lift and remove the cut portion of the existing pile 32. The lifting wire 30A is removed from the removed 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. 6, after cutting, the removed lifting wire 30A is connected to the upper part of the existing pile 32 suspended by the hanging wire 38, and the crane After the existing pile 32 is pulled up by the arrow 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, debris falls at a location on the existing pile 32 located below the scheduled cutting location X, which is the next location to be cut on the existing pile 32. The existing pile 32 is pulled up within the long groove 4202 so as to be positioned above the prevention plate 40.
Then, one end of the removed hanging wire 38 is connected to a location on the existing stake 32 located below the location to be cut next. Further, 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.

Thereafter, similarly, as shown in FIG. 4 and FIG. A net 46 is placed on the debris fall prevention plate 40, and then the existing pile 32 is cut at the location where it should 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 this embodiment, when the existing piles 32 that are separated from the ground G are pulled up, cut, and removed at predetermined lengths, large debris (concrete fragments) generated during cutting is prevented from falling. Debris is prevented from falling into the hemmed hole 34 as it is caught by the plate 40 and the net 46 placed thereon.
Therefore, it is advantageous to smoothly improve the muddy water in the hole 34 after removing the existing pile 32 to the same level as the surrounding ground G.
Furthermore, in this embodiment, the simple configuration of supporting the portion of the existing pile 32 located below the cut point using the hanging wire 38 is sufficient, so that the removal work of the existing pile 32 can be made more efficient. It will be advantageous above.

Further, according to the present embodiment, since the lower end of the leader 14 of the excavation equipment 10 is placed on the base 20, the load is applied to the base 20 from the existing pile 32 via the hanging wire 38. In this case, it is advantageous to stably install the base 20 on the ground G.

(Second embodiment)
Next, a second embodiment will be described using FIGS. 8 to 11 and referring to FIGS. 13 to 20.
In the following embodiments, the same parts and members as in the first embodiment are given the same reference numerals as in the first embodiment, and the explanation thereof will be omitted.
In the first embodiment, a case has been described in which the existing pile 32 is pulled up using the crane 12 of the excavation rig 10.
On the other hand, in the second embodiment, as shown in FIG. 20, a mobile crane 48 is prepared separately from the excavation rig 10, and the wire 50 of the mobile crane 48 is used as the lifting wire 50A. This embodiment differs from the first embodiment in that the pile 32 is pulled up.
In addition, in the second embodiment, a part of the existing pile 32 below the planned cutting part X is connected to a hanging wire 38 (hereinafter referred to as a first hanging wire 38) connected to the base 20, This embodiment differs from the first embodiment in that the second hanging wire 52, which is hoisted and let out by the crane 12 of the excavating rig 10, is supported by two hanging wires 38 and 52. . Although the second suspension wire 52 corresponds to the suspension wire 30A in the first embodiment, for convenience of explanation, it will be described as the second suspension wire 52.

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 piles 32, and the The lower end of 14 is installed on base 20.
Furthermore, a mobile crane 48 is installed on the ground G near the existing pile 32. The mobile crane 48 is equipped with a first winch (not shown) that winds up and lets out the lifting wire 50A.
As the mobile crane 48, for example, 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 excavation equipment 10 is equipped with a second winch (not shown) that winds up and lets out a second hanging wire 52, which will be described later.

As shown in FIG. 13, a lifting wire 50A is let out from the mobile crane 48 (first winch), and one end thereof is wrapped around and connected to the outer peripheral surface of the upper part of the existing pile 32 exposed from the ground G.

Next, as shown in FIG. 14, the lifting wire 50A is hoisted up by the mobile crane 48 (first winch), and the existing pile 32 is moved so that the planned cutting point X is located upwardly away from the base 20. raise.
Then, as shown in FIGS. 9A, 9B, and 14, the position adjustment members 36 are arranged on the pile holder 26 .
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 holder 26.

Next, as shown in FIGS. 15 and 10, similarly to the first embodiment, the debris fall prevention plate 40 is installed on the position adjustment member 36, and the long groove 4202 is closed with the opening/closing plate part 44 in the closed position. 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 through the wire insertion notch 4204, and the existing pile located below the planned cutting location Wrap it around the outer peripheral surface of No. 32 and connect it.
Furthermore, one end of the second suspension wire 52 of the crane 12 of the excavation rig 10 is wound around and connected to the outer periphery of the existing pile 32 which is located above and away from one end of the first suspension wire 38. At this time, one end of the second hanging wire 52 is positioned so that the second hanging wire 52 extending vertically in a plan view is located within the wire insertion notch 4204, and attached to the existing pile 32. 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 connected so that the planned cutting point X of the existing pile 32 is located above the debris fall prevention plate 40. The existing pile 32 is movable so that it is located in the wire insertion notch 4204 and one end of the first hanging wire 38 and one end of the second hanging wire 52 are positioned below the debris fall prevention plate 40. It is lowered via the lifting wire 50A of the crane 48.
Then, due to the weight of the existing pile 32, the lifting wire 50A, the first hanging wire 38, and the second hanging wire 52 are brought into tension. At this time, the amount of hoisting of the second hanging wire 52 by the crane 12 (second winch) of the excavation rig 10 is such that both the first hanging wire 38 and the second hanging wire 52 are in a tension state. Or adjust the amount of feed.
Next, a net 46 is placed 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 fragments) falls around the existing pile 32, but
Since the debris is caught by the debris fall prevention plate 40 and the net 46 placed thereon, debris is prevented from falling into the edged hole 34.
Note that when the existing pile 32 is cut, the existing pile 32 below the cut point is supported by the base 20 via the first hanging wire 38, and is also supported by the base 20 via the second hanging wire 52. Since it is supported by the crane 12 of the excavation rig 10, it will not fall.

Then, the mobile crane 48 (first winch) winds up the lifting wire 50A to lift and remove the cut portion of the existing pile 32. The lifting wire 50A is removed from the removed 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 hanging wires 38, 52, and the first, After pulling up the existing pile 32 by the mobile crane 48 (first winch) to such an extent that the second hanging wires 38 and 52 are slack, one end of the first and second hanging wires 38 and 52 is removed 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, by hoisting the lifting wire 50A using the mobile crane 48 (first winch), the existing pile 32 is located below the scheduled cutting location X, which is the next location to be cut. The existing pile 32 is pulled up within the long groove 4202 so that the position 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 a part of the existing pile 32 located below the part to be cut next, and one end of the first hanging wire 38 is connected 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. Further, 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.

Thereafter, 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 suspended by the weight of the existing pile 32. A net 46 is placed on the debris fall prevention plate 40 around the existing pile 32 under tension, and then the existing pile 32 is cut at the location where it should 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 effects as those of the first embodiment can be achieved, and the cutting location is reduced 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 point can be reliably supported by the two wires, so even if one of the wires is cut, the existing pile 32 can be prevented from falling. This is advantageous in ensuring safety in the removal work of the piles 32.

Further, according to the second embodiment, a winch included in the excavation rig 10 is used as the first winch, and a winch included in the mobile crane 48, which is separate from the excavation rig 10, is used as the second winch.
Therefore, in addition to the first winch of the excavation rig 10 that removes the existing pile 32, the second winch provided on the general-purpose mobile crane 48 can be used, so there is no need to prepare special heavy equipment. This is advantageous in reducing the cost required for removing the existing piles 32.

10 Excavation equipment 12 Crane 1202 Crawler 1204 Lower traveling body 1206 Upper traveling body 1208 Boom 14 Leader 15 Leader bracket 16 Rotation drive section 18 Casing 1802 Casing divided body 1804 Cutter 20 Base 22 Lower girder material 24 Upper girder material 26 Pile support 26A Base parts 26B, 26C Side part 2602 Hook 28 First wire 30 Second wire 30A Lifting wire 32 Existing stake 34 Hole 36 Position adjustment member 38 Hanging wire (first hanging wire)
40 Debris fall prevention plate 42 Main body plate 4202 Long groove 4204 Notch for wire insertion 44 Opening/closing plate 46 Net 48 Mobile crane 50 Wire 50A Lifting wire 52 Second hanging wire

Claims (5)

A method for removing existing piles that is separated from the ground by pulling it up at predetermined lengths, cutting it, and removing it,
Place a base on the ground around the existing pile,
Connecting a lifting wire to the upper part of the existing pile and lifting the existing pile so that the part of the existing pile located below the part of the existing pile to be cut is located above the base;
Connecting one end of the suspension wire to a location of the existing pile located below the location to be cut, and connecting the other end of the suspension wire to the base;
On the base, there is a long groove extending with a width that allows the existing pile to move up and down and having one longitudinal end open, and a cutout for wire insertion that is open at the other end of the long groove. A debris fall prevention plate is positioned and placed so that the existing pile can move up and down within the long groove,
The part of the existing pile to be cut is positioned above the debris fall prevention plate, and the hanging wire is positioned within the wire insertion notch, so that the one end of the hanging wire is positioned above the debris fall prevention plate. Lowering the existing pile via the lifting wire so that it is located below the debris fall prevention plate,
the lifting wire and the hanging wire are brought into tension by the weight of the existing pile;
placing a net on the debris fall prevention plate around the existing pile;
cutting the existing pile at the point to be cut, removing the lifting wire, removing the cut portion of the existing pile and removing the net;
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 becomes slack, and then the hanging wire is Remove the wire and
lifting the existing pile within the long groove using the lifting wire so that the part of the existing pile located below the part of the existing pile to be cut next is located above the debris fall prevention plate;
Connecting one end of the removed hanging wire to a location of the existing pile located below the location to be cut next, and connecting the other end of the hanging wire to the base;
Thereafter, in the same manner as above, the existing pile is lowered, the lifting wire and the hanging wire are put under tension due to the weight of the existing pile, and a net is placed on the debris fall prevention plate around the existing pile. , cut the existing pile at the next point to be cut, and remove the cut part of the existing pile,
Do this kind of work repeatedly,
A method for removing existing piles characterized by: A method for removing existing piles that is separated from the ground by pulling it up at predetermined lengths, cutting it, and removing it,
Place a 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 part of the existing pile located below the part of the existing pile to be cut is located above the base. pull up the existing pile,
Connecting one end of the first suspension wire to a location of the existing pile located below the location to be cut, and connecting the other end of the first suspension wire to the base;
Connecting one end of a second hanging wire connected to a second winch to a location of the existing pile located below the location to be cut,
On the base, there is a long groove extending with a width that allows the existing pile to move up and down and having one longitudinal end open, and a cutout for wire insertion that is open at the other end of the long groove. A debris fall prevention plate is positioned and placed so that the existing pile can move up and down within the long groove,
The first and second suspension wires are positioned so that the part of the existing pile to be cut is located above the debris fall prevention plate, and the first and second hanging wires are located within the wire insertion cutout. 2 lowering the existing pile via the lifting wire so that the 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 brought into tension by the weight of the existing pile;
placing a net on the debris fall prevention plate around the existing pile;
cutting the existing pile at the point to be cut, removing the lifting wire, removing the cut portion of the existing pile and removing the net;
After cutting, connect the removed lifting wire to the upper part of the existing pile suspended by the first and second hanging wires, and connect the first and second hanging wires to the extent that the first and second hanging wires become slack. After pulling up the existing pile with a winch, one end of the first and second hanging wires is removed,
lifting the existing pile within the long groove using the lifting wire so that the part of the existing pile located below the part of the existing pile to be cut next is located above the debris fall prevention plate;
One end of the removed first and second suspension wires is connected to a location of the existing pile located below the location to be cut next, and the other end of the first suspension wire is connected to the base. connected to,
Thereafter, in the same manner as described above, the existing pile is lowered, the lifting wire and the first and second hanging wires are put under tension due to the weight of the existing pile, and the debris falls around the existing pile. Placing a net on the prevention plate, cutting the existing pile at the next point to be cut, and removing the cut part of the existing pile,
Do this kind of work repeatedly,
A method for removing existing piles characterized by: The debris fall prevention plate is arranged between the main body plate portion having the long groove and the wire insertion notch, and a closed position where the open long groove portion is closed and an open position where the long groove portion is opened. and an opening/closing plate part swingably connected to the part,
After aligning and placing the fall prevention plate on the base, swinging the opening/closing plate part from the open position to the closed position;
The method for removing existing piles according to claim 1 or 2, characterized in that: The edge of the existing pile with the ground is cut by rotating a casing around the outer periphery of the existing pile using a rotation drive unit of an excavation device,
The excavation device includes a leader that guides the rotary drive unit in the vertical direction,
a lower end of the leader is placed on the base;
The method for removing an existing pile according to any one of claims 1 to 3. The first winch is a winch included in the excavation equipment,
The second winch is a winch included in a mobile crane that is separate from the excavation equipment.
The method for removing existing piles according to claim 4, which refers to claim 2.

Images