JP7054303B2 - Removal device and removal method - Google Patents

Description

The present invention relates to a technique for removing existing anchors such as ground anchors provided on a slope and buried objects such as existing piles buried in the ground.

When rebuilding a construction structure, it is necessary to remove the existing anchors (groutondo anchors, etc.) installed on the slope and the unnecessary existing piles buried in the foundation of the building. There is.
When removing such a buried object, in the prior art, so-called "cover digging" is performed with a diameter that is one size larger than the outer diameter of the buried object, and the buried object is collected at once over the entire length. It has been.
Here, when the cover digging over the entire length of the buried object is not successful, for example, as shown in FIG. 8, the drilling direction of the cover digging and the extension direction of the buried object (for example, the existing anchor A) to be removed coincide with each other. When the portion of the tip member 12 (22) other than the drilling tip T comes into contact with the tension material AT of the anchor A, it is difficult to dig further. In such a case, the tension material AT (tendon: for example, steel stranded wire) of the existing anchor A and the drilling tip T of the tip member 12 (22) intersect, and the tension material AT of the existing anchor A is cut. To. Then, the buried objects up to that point have been collected and the removal has been completed.

In the removal of the buried object as described above, for example, the recovery of the tension material of the existing anchor is performed at the same time as the extubation of the casing used for the covering digging.
However, in the machine used for cover digging, there is a limit to the length that can be pulled out on the ground side, and in the work of extubating the casing containing the continuous tensile material, the length of the casing to be extubated is very long. Therefore, it is difficult (with existing machines) to expose the entire length of the casing on the ground side.
It is conceivable to bend the contained tension material to separate the casing for each unit length, but since the tension material is composed of, for example, PC steel stranded wire, the bent tension material is sharply straightened due to its elasticity. If it returns to the state, it poses a great danger to the workers.

Therefore, when removing a buried object (for example, an existing anchor), a technique for cutting the buried object at an arbitrary position is required.
However, a technique capable of suitably cutting an embedded object such as an existing anchor including a tension material (for example, a PC steel stranded wire) at an arbitrary position has not yet been proposed.
The applicant has proposed a removal device and a removal method having a simple structure for cutting a long buried object such as an existing anchor to a desired length and removing it from the ground (see Patent Document 1). With such a removal device and a removal method, it has been difficult to reliably cut a pulling material composed of, for example, PC steel stranded wire.
Further, the removal device (Patent Document 1) is premised on the use of a double pipe, and can be applied to excavation using a single hollow pipe (single pipe) (so-called "single pipe excavation"). Can not.

Japanese Unexamined Patent Publication No. 2016-53279

The present invention has been proposed in view of the above-mentioned problems of the prior art, and it is easy and reliable to cut an object to be cut such as an existing anchor including a tension material made of stranded PC steel at a desired position. It is an object of the present invention to provide a cutting device that enables cutting to a single pipe and is also applicable to single-tube excavation, and a removal method to which the cutting device can be applied.

The removal device (10) of the present invention is the removal device (10) for cutting and removing the anchor (A).
An excavator (1) is installed on the ground side,
The hollow pipe (for example, a single pipe 11) is separated for each unit length, the anchor (A) entering the inside of the hollow pipe (11) is exposed on the ground side, and the anchor (A) is cut at the exposed portion. A cutting device (4), a guide rail (2A), a driving device (2B) and a swivel (16) are provided in the excavating device (1).
The cutting device (4) is arranged on a guide rail (2A) and has a function of cutting an anchor (A) that has entered the inside of a hollow pipe (11) that moves along the guide rail (2A).
The guide rail (2A) has a function of moving the hollow pipe (11) along the guide rail (2A).
The hollow tube (11) is accessible to the anchor (A) to be cut inward.
The swivel (16) is characterized in that it has a function of rotating in a direction of releasing the screwing between the hollow tubes (11).

The removal method of the present invention is the removal method using the above-mentioned removal device (10: removal device according to claim 1).
Anchor (A) to be cut is inserted into the hollow pipe (11) from the opening of the hollow pipe (11) that moves along the guide rail (2A) provided in the excavator (1) of the removal device (10). The process of getting inside and
It has a step of cutting the anchor (A) that has entered the inside of the hollow tube (11).
The cutting step is
The process of separating the hollow pipe (11) for each unit length and exposing the anchor (A) that has entered the inside of the hollow pipe (11) on the ground side.
It is characterized by including a step of cutting an anchor (A) at an exposed portion on the ground side by a cutting device (4) arranged on a guide rail (2A) of the removing device (10) .

Further, the removal device (10) of the present invention is the removal device (10) for cutting and removing the anchor (A).
The guide rail (2A), the hollow pipe (11) in which the hollow pipes of a unit length (for example, a single pipe 11) are screwed together, and the hollow pipes (11) rotate in a direction to be unscrewed. Equipped with a functional swivel (16)
The guide rail (2A) has a function of moving the hollow pipe (11) along the guide rail (2A).
An anchor (A) to be cut can enter the hollow portion of the hollow tube (11).
The main body (15) is connected to the underground tip of the hollow pipe (11), and the underground cutting mechanism (14) having a function of cutting the anchor (A) in the ground is attached to the main body (15). ) Is connected,
The underground cutting mechanism (14) is provided on the underground side of the hollow pipe (11), and when the swivel (16) rotates in the direction of unscrewing the hollow pipe (11), the inside of the hollow pipe (11) is unscrewed. A hollow member (14A) that moves relative to the empty pipe (11) and advances to the tip bit (13) side provided at the tip of the hollow tube (11) on the underground side, and the hollow member (14A) is the tip. It is characterized by having a cutting member (14B) that moves inward in the radial direction and cuts the anchor (A) when traveling toward the bit side.
Alternatively, the removal device (20) of the present invention is the removal device (20) that cuts and removes the anchor (A).
It has a function of rotating in a direction of unscrewing the guide rail (2A), the hollow pipe (21) in which the hollow pipes (21) having a unit length are screwed together, and the hollow pipes (21). Equipped with a swivel (16)
The guide rail (2A) has a function of moving the hollow pipe (21) along the guide rail (2A).
An anchor (A) to be cut can enter the hollow portion of the hollow tube (21).
A bit body (25) is connected to the underground tip of the hollow tube (21), and a tip bit (23) is provided on the underground side of the bit body (25). It has an opening (23A) and a hollow portion, and has an underground cutting mechanism (24) that cuts the anchor in the ground.
The underground cutting mechanism (24) includes a tip bit side cutting blade (23B) provided on the inner peripheral portion of the opening (23A) of the bit body (25) and a hollow portion of the bit body (25). A cutting jig (24A) arranged on the ground side of the above and having an opening, and a cutting jig side cutting blade (24B) provided on the inner peripheral portion of the opening of the cutting jig (24A). The center of the opening (23A) of the tip bit (23) and the center of the opening of the jig (24A) are eccentric with respect to the central axis of the hollow tube (21), and the cutting is performed. When the tool jig (24A) is rotated relative to the tip bit (23), the tip bit side cutting blade (23B) and the cutting tool side cutting blade (24B) rotate relatively to the tip bit (24A). It is characterized by having a function of closing the opening (23A) of 23) and cutting the anchor (A).

At the time of carrying out the present invention, an excavation tip is arranged at the tip (the tip on the underground side) of the hollow pipe (11, 21), and an opening through which the object to be cut (A) to be cut penetrates is formed. Tip bits (13, 23) are provided.
By excavating the peripheral region of the object to be cut (A) with the tip bit (13, 23) at the tip of the hollow tube (for example, single tube 11, 21), the object to be cut is cut from the opening of the hollow tube (11, 21). Insert the object (A) into the hollow tube (11, 21) (cover digging),
It is preferable to move (pull) the cutting object (A) that has entered the inside of the hollow pipe (11, 21) to the ground side and remove it from the excavator (1).
Then, an underground cutting mechanism (14, 24) for the object to be cut (A) is provided between the tip bit (13, 23) and the hollow pipe (11, 21), and the underground cutting mechanism (14, 24) is provided. The object to be cut (A) also penetrates inside 14 and 24).
The underground cutting mechanism (14, 24) has a function of transmitting the rotation of the hollow tube (11, 21) in the normal rotation direction to the tip bit (13, 23), and the hollow tube (11, 21). It is preferable to have a mechanism having a function of cutting the object to be cut (A) (extending inside the opening) when the object is reversed.

Further, the removal method of the present invention is the removal method using the above-mentioned removal device (10: removal device according to claim 2).
The step of allowing the anchor (A) to be cut from the opening of the hollow pipe (11) to enter the inside of the hollow pipe (11), and
It has a step of cutting the anchor (A) entering the inside of the hollow pipe (11) in the ground by the underground cutting mechanism (14).
In the cutting step, the swivel (16) rotates in the direction of releasing the screwing of the hollow pipe (11), and the hollow member (14A) provided on the underground side of the hollow pipe (11) is said. It is moved relative to the hollow pipe (11) to advance to the tip bit (13) side provided at the tip of the hollow pipe (11) on the underground side, and is advanced to the cutting member (14B) of the underground side cutting mechanism (14). ) Is moved inward in the radial direction of the anchor (A) to cut the anchor (A).
Alternatively, the removal method of the present invention is the removal method using the removal device (20: the removal device of claim 3).
A step of allowing the anchor (A) to be cut from the opening of the hollow tube (21) of the removal device (20) to enter the inside of the hollow tube (21).
It has a step of cutting the anchor (A) entering the inside of the hollow pipe (21) on the underground side by the underground side cutting mechanism (24).
In the cutting step, the swivel (16) rotates the hollow tube (21) in the direction of unscrewing, and the cutting jig (24A) is rotated in the direction of the hollow tube (21). Rotates relative to the tip bit (23) and relatively rotates the tip bit side cutting blade (23B) and the cutting jig side cutting blade (24B) to close the opening in the tip bit (23). It is characterized in that the anchor (A) is cut.

According to the cutting device (4) of the present invention having the above-mentioned configuration, the object to be cut (A: buried object, for example, an existing anchor) can be cut at an arbitrary position on the guide rail (2A). If the present invention is provided in the removal device (10, 20), the single tube (11, 21) on the most ground side is cut off, and the object to be cut (A) is exposed from the inside of the single tube (11, 21). Then, it can be cut by the cutting device (4).
Therefore, the single tube (11, 21) can be separated and the object to be cut (A) can be cut without bending the single tube (11, 21).

Then, according to the cutting apparatus (4) of the present invention, even if it is a cutting object (A: for example, an existing anchor using a PC steel stranded wire as a tensile material), the cutting object can be reliably used. Can be disconnected.
Moreover, if the present invention is provided in the removal device (10, 20), the amount of movement (stroke) required to expose the object to be cut (A) is equal to the unit length of the single tube (11, 21). Since it is sufficient, there is no need to significantly modify the existing equipment (removal device or excavation device).

When the cutting device (4) of the present invention is provided in the removing device (10, 20) and the underground cutting mechanism (14, 24) is used, the object to be cut (buried object A: existing). At the point on the underground side where the anchor or existing pile should be cut, the underground tip of the removal device (10, 20) (excavation tip of tip bits 13 and 23) is pressed against the ground (the excavation tip bites into the ground). The object to be cut (A) can be cut by a very simple operation of fixing the tip bits 13 and 23) and reversing the hollow tubes (for example, single tubes 11 and 21) constituting the removal device (10, 20). ) Can be reliably cut at a desired location.

When the cutting device (4) of the present invention is provided in the removing device (10, 20) and the underground cutting mechanism (14, 24) is used, the cutting object (A) is cut. After that, when the state where the tip bit (13, 23) is pressed against the ground is released and the hollow pipe (11, 21) is pulled up to the ground side, the cut piece of the object to be cut (A) is pulled up to the ground side. Can be done.
Here, when the underground side cutting mechanism (14, 24) is used, in the state where the cutting object (A) is cut, the underground side cutting mechanism (14, 24) holds the cut piece (the state where the cut piece is held. Since the cutter is closed, or the positions of the openings of the tip bits 13 and 23 and the openings of the cutting jigs 14B and 24B are closed without overlapping), the hollow tube (11, 21). The cut piece of the object to be cut (A) does not fall and remain in the ground even if it is pulled up.
Even when the underground cutting mechanism (14, 24) is used, the hollow pipe constituting the removal device (10, 20) is composed of a “single pipe or a single hollow pipe (11, 21)”. Therefore, the buried object (A) can be cut for each cut piece by so-called "single pipe excavation".

As described above, according to the cutting device (4) of the present invention, the object to be cut (A) can be easily and surely cut at a desired position on the ground side, so that the underground side cutting mechanism (14) can be easily and surely cut. , 24), the object to be cut (A) can be easily and surely cut at a desired location not only on the ground side but also in the underground side. Therefore, the object to be cut (A) can be cut at a desired position on both the underground side and the ground side.
Further, if the object to be cut (A) is cut to a predetermined length (for example, the length dimension of the casing) or less on the ground side by the cutting device (4) of the present invention, the underground side cutting mechanism can be obtained in the underground region. The object to be cut (A) can be easily and safely removed without cutting the buried object (A) according to (14, 24).
On the other hand, if the object to be cut (A) is cut to a predetermined length (for example, the length dimension of the casing) or less by the underground side cutting mechanism (14, 24), the object to be cut is not cut on the ground side. (A) can be easily and safely removed.
In this case, whether to cut only on the ground, only in the ground, or both on the ground and in the ground depends on the length (or reach depth) of the object to be cut (A) and the construction site. It is possible to select in consideration of various conditions. In other words, if the underground cutting mechanism (14, 24) is used in the present invention, optimum construction is performed in consideration of the length (or reach depth) of the object to be cut (A) and various conditions at the construction site. It is possible to choose the method.

It is a side view which shows the excavation apparatus in the removal apparatus to which the cutting apparatus which concerns on embodiment of this invention is applied, and is explanatory drawing which omitted the cutting apparatus. It is explanatory drawing which shows the main part of the removal device, and is also the process drawing which shows the stage before cutting the tension material of an anchor by a cutting device. It is the same explanatory view as FIG. 2, and is also a process diagram which shows the process of cutting the tension material of an anchor by a cutting apparatus. It is the same explanatory view as FIG. 2 and FIG. 3, and is also a process diagram which shows the state after cutting the tension material of an anchor by a cutting device. It is explanatory drawing which shows an example of the cutting apparatus which concerns on the illustrated embodiment. It is explanatory drawing which shows the other example of the cutting apparatus which concerns on the illustrated embodiment, and is different from the example shown in FIG. FIG. 5 is an explanatory diagram showing another example of the cutting device according to the illustrated embodiment, which is different from those shown in FIGS. 5 and 6. It is explanatory cross-sectional view explaining the state which should cut the anchor which is a buried object. It is sectional drawing which shows the underground side cutting mechanism which concerns on 1st modification, and is the sectional drawing which shows the state which excavates the ground around an anchor without cutting an anchor. It is sectional drawing which shows the underground side cutting mechanism which concerns on the 1st modification, and is the sectional drawing which shows the state which the anchor was cut. It is a perspective view of the underground side cutting mechanism which concerns on the 2nd modification. FIG. 11 is a cross-sectional view of FIG. It is sectional drawing of FIG. 11 in the state different from FIG. It is a schematic diagram for demonstrating the cutting in 2nd modification. It is a schematic diagram which shows the state which the relative position of the tip bit and the cutting jig in the state of excavating around the anchor A is seen from the reference numeral A1 side of FIG. It is a schematic diagram showing the position where the tip bit and the cutting jig are rotated by 90 ° relative to the state of FIG. 15 when viewed from the reference numeral A1 side of FIG. It is a schematic diagram showing the position where the tip bit and the cutting jig are rotated by 180 ° relative to the state of FIG. 15 when viewed from the reference numeral A1 side of FIG. FIG. 12 is a diagram showing a state seen from the reference numeral A1 side of FIG. 12, and is an explanatory diagram schematically showing a relative position between a tip bit and a cutting jig when excavating the periphery of an anchor. FIG. 12 is a diagram showing a state seen from the reference numeral A1 side of FIG. 12, and is an explanatory diagram schematically showing the relative positions of the tip bit and the cutting jig when the anchor is cut.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the illustrated embodiment, the anchor A, which is a buried object, is exemplified as the object to be cut to be cut.
In FIG. 1, the cutting device (4) according to the embodiment of the present invention is provided in the removing device 10 (20), and the removing device 10 (20) is attached to the head 2 of the excavating device 1. The head 2 includes a guide rail 2A and a drive device 2B, and the removal device 10 (20) can be extended or pulled back at predetermined stroke intervals. Here, although not provided in the excavation device 1 shown in FIG. 1, the removal device 10 (20) includes a cutting device 4 for cutting the tensile material of the anchor A on the ground side (FIGS. 2 to 7). reference).
In FIGS. 1 to 4, as the removal device provided with the cutting device 4, there are a removal device indicated by reference numeral 10 and a removal device indicated by reference numeral 20. The removal device 10 is a removal device provided with the underground side cutting mechanism 14 according to the first modification described later with reference to FIGS. 9 to 10. Further, the removal device 20 is a removal device provided with the underground side cutting mechanism 24 according to the second modification described later with reference to FIGS. 11 to 19. The single tube (hollow tube) used in the first modification is indicated by reference numeral 11, and the single tube (hollow tube) used in the second modification is indicated by reference numeral 21.
In FIG. 1, the excavator 1 has an arm 3, and the tilt angle and the like of the head 2 are freely adjusted by the arm 3 to adjust the head 2 to the angle at which the anchor A (see FIG. 8) is embedded. be able to. When removing the anchor A, the central axis of the removal device 10 (20) mounted on the head 2 is adjusted so as to be coaxial with the central axis of the anchor A.

The removal device 10 (20) includes a single tube 11 (21) and a swivel 16. Although not shown in FIG. 1, the anchor A to be removed can enter the internal space of the single tube 11 (21), and the tip member 12 is at the tip (underground side tip) of the single tube 11 (21). (22) (FIG. 8) is provided, the tip member 12 (22) includes a tip T, and has a tip bit 13 (23) (FIG. 9, FIG. 10, FIG. 12, FIG. 13). The tip bit 13 (23) is formed with an opening through which the anchor A to be removed enters.
In FIG. 1, the drive device 2B includes a feed device 2BA and a rotary motor 2BB, and the single tube 11 (21) is moved along the guide rail 2A by the feed device 2BA and is rotationally driven by the rotary motor 2BB. ..

When removing the existing anchor A (FIG. 8) using the removal device 10 (20) described above, first, the removal device 10 (20) held by the head 2 of the excavation device 1 from the slope surface (ground surface). ) Is placed on the ground side end of the anchor A, and the anchor A is formed by the tip bit 13 (23) (FIG. 9, FIG. 10, FIG. 12, FIG. 13) of the tip (underground side tip) of the single tube 11 (21). The surrounding area is excavated, and the anchor A is made to enter the inside of the single pipe 11 (21) through the opening of the single pipe 11 (21) (so-called “covering step”).
After digging along the anchor A by the cover digging step and excavating the peripheral area over the entire length of the anchor A, the anchor A that has entered the inside of the single pipe 11 (21) is pulled out to the ground side and removed from the excavation device 1. (Recovery process).

As will be described later with reference to FIGS. 9 to 19, the underground cutting devices 14 and 24 (not shown in FIGS. 1 to 7: see FIGS. 9 to 19) for cutting the anchor A in the ground are simply used. When provided at the tips of the pipes 11 and 21, if the tension material of the anchor A is covered and dug by a predetermined length or a predetermined depth in the stretching direction, the anchor A is provided by the underground cutting devices 14 and 24. (Cut process).
Alternatively, when the drilling direction of the covering digging and the anchor stretching direction do not match and are uneven, as shown in FIG. 8, the portion of the tip member 12 (22) other than the drilling tip T is an anchor. Even when it comes into contact with the tension material AT of A, the anchor A is cut by the cutting step.
When the anchor A is cut, the cut fragment of the anchor A is discharged to the ground (recovery step).

In the recovery process, the single pipe 11 (21) is pulled up to the ground side regardless of whether the cover is dug over the entire length of the anchor A or the anchor A is cut in the ground.
However, the stroke of the guide rail 2A is set to the unit length of the single pipe 11 (21), and as shown in FIG. 2, the length of the anchor A or a fragment thereof pulled out to the ground side is the length of the excavator 1. It is sufficiently longer than the stroke of the guide rail 2A of the head 2. Therefore, the anchor A or a fragment thereof pulled out to the ground side cannot be excluded from the excavator 1.
In the prior art, in the state shown in FIG. 2, the anchor A exposed on the ground is forcibly bent (the bent state is not shown), and the single tube 11 (21) on the most ground side is separated in the state where the anchor A is bent. Was there. However, the tension material AT existing at the center of the anchor A is, for example, a PC steel stranded wire, and has high rigidity and elastic repulsion. Therefore, at the moment when the single tube 11 (21) on the most ground side is separated, the anchor A may be suddenly restored to a straight state due to the strong elastic repulsive force of the tension material AT. If the anchor A is suddenly restored to a straight state, the anchor A may collide with a worker around the excavator 1, and the disconnection of the single pipe 11 (21) becomes a very dangerous work.

On the other hand, the removal device 10 (20) provided with the cutting device 4 according to the illustrated embodiment has a function of cutting the anchor A that has entered the inside of the single pipe 11 (21) (hollow pipe) on the ground side. A cutting device 4 is provided.
In FIG. 2, for example, after performing cover digging over the entire length of anchor A (cover digging step), the drive device 2B is driven in the recovery step, and the single pipe 11 (21) is driven along the guide rail 2A of the excavation device 1. The state of being pulled up to the ground side is shown. An anchor A shown by a broken line and a tension material AT composed of a PC steel stranded wire have entered the inside of the pulled-up single tube 11 (21).

In FIGS. 2 and 3, the single tube on the most ground side (right side in FIGS. 2 and 3) is designated by reference numeral 11-1 (21-1), and the single tube on the most ground side is more ground than 11-1 (21-1). The single tube connected to the middle side (left side in FIGS. 2 and 3) is indicated by reference numeral 11-2 (21-2). Although not shown, the single pipe 11-3 (21-3) is further connected to the underground side of the single pipe 11-2 (21-2), and the single pipe 11-4 (21-4), ... is connected.
The single pipes 11-1 (21-1) and the single pipes 11-2 (21-2) are connected to each other by screwing a male screw and a female screw, and the single pipes 11-1 (21-1) have an attachment 17. It is connected to the swivel 16 via. Then, the swivel 16 rotates in the direction of releasing the screwing between the single tubes, so that the single tubes 11-1 (21-1) are separated from the single tubes 11-2 (21-2) and the attachment 17.
The vicinity of the end portion of the single tube 11-2 (21-2) on the ground side (right side in FIGS. 2 and 3) is supported on the guide rail 2A by the support members 18 (for example, a plurality of members). The support member 18 is arranged on the underground side (left side in FIGS. 2 and 3) from the single pipe 11-1 (21-1) on the most ground side.

In the guide rail 2A of the head 2 of the excavator 1, the region on the ground side of the support member 18 where the single pipe 11-1 (21-1) on the ground side is located most in FIG. 2 is located in the region on the ground side. The cutting device 4 according to the illustrated embodiment is arranged. The cutting device 4 includes, for example, a rotary blade 4A, a motor 4C for rotationally driving the rotary blade 4A, and an operation handle 4B, and is configured to be capable of cutting the tension material AT composed of the anchor A and the PC steel stranded wire. ing.
When cutting the anchor A (and the tension material AT), first, the anchor A (and the tension material AT) that has entered the inside of the hollow pipe 11 (21) is placed on the ground side of the hollow pipe 11 (21). Expose from. Specifically, from the state shown in FIG. 2, as shown in FIG. 3, the single pipe 11-1 (21-1) on the most ground side is connected (adjacent) to the underground side. Separate from (21-1) and move to the ground side (right side in FIG. 3). As a result, at the place where the cutting device 4 is provided, the tension material AT composed of the anchor A and the PC steel stranded wire is exposed from the single tube 11-1 (21-1).

Next, in the state shown in FIG. 3, the anchor A (and the tension material AT) is cut by the cutting device 4 (cutting step). After cutting the anchor A with the cutting device 4, the single tube 11-1 (21-1) on the most ground side is separated (removed) from the attachment 17 (swivel 16 side), and the cut section of the anchor A is excavated by the excavator 1. Removed from the guide rail 2A (exclusion step).
In this way, since the anchor A can be cut at a predetermined position on the ground side by using the cutting device 4 according to the illustrated embodiment, the single pipe 11-1 (at that time, without bending the anchor A) ( 21-1) can be separated and removed from the guide rail 2A of the excavator 1.
In this case, it is sufficient that the stroke of the excavating device 1 is equal to the unit length of the single pipe 11 (21-1), as in the device used in the prior art.

In the process shown in FIG. 3, the anchor A (and the tension material AT) is cut, the single pipe 11-1 (21-1) is removed, and the cut anchor A (and the tension material AT) is removed from the guide rail 2A of the excavator 1. After removal, as shown in FIG. 4, the ground side end of the single tube 11-2 (21-2) is connected to the attachment 17. Alternatively, the ground side end portion (right end portion in FIG. 4) of the single tube 11-2 (21-2) is gripped by the attachment 17.
In that state, the drive device 2B is driven, and the single pipes 11-2 (21-2) and the single pipes 11-3, 11-4, etc. (21-3, 21-3, which are continuously connected to the underground side thereof) are connected. 21-4, etc.) (not shown) are moved along the guide rail 2A to the ground side (right side in FIG. 4) within the stroke range of the guide rail 2A. When the movement is completed, the state is similar to that in FIG. That is, in FIG. 2, the single tube 11-1 (21-1) is replaced with the single tube 11-2 (21-2), and the single tube 11-2 (21-2) is replaced with the single tube 11-3 (21-3). It will be replaced with.

After that, from the state shown in FIG. 2 again, as shown in FIG. 3, the single pipe 11-2 (21-2) on the most ground side is separated from the adjacent single pipe 11-3 (21-3) on the underground side. , Moved to the ground side (right side in FIGS. 2 and 3) to expose the tension material AT composed of the anchor A and the PC steel stranded wire on the ground side (state in FIG. 3).
Then, as shown in FIG. 3, the anchor A is cut by the cutting device 4, the single pipe 11-2 (21-2) is removed from the attachment 17, and the cut anchor A (and the tension material AT) is removed from the excavator 1. Remove from guide rail 2A.
Hereinafter, the steps shown in FIGS. 2, 3 and 4 are repeated, and the anchor A (and the tension material AT) pulled out to the ground side or a fragment thereof is easily and safely removed from the excavator 1.

FIG. 5 shows an example of the cutting device 4. The cutting device 4 has a function of rotating the rotary blade 4A to cut the buried object (anchor A in the illustrated embodiment).
The cutting device 4 has an operation handle 4B, a motor 4C that rotationally drives the rotary blade 4A, a main body portion 4D that surrounds the motor 4C, and a mounting portion 4F that rotatably supports the main body portion 4D by a rotary shaft 4E. There is. The cutting device 4 is attached to the guide rail 2A of the excavating device 1 by the mounting portion 4F. When cutting the anchor A, the operation handle 4B is operated to bring the rotary blade 4A close to the anchor A, and the rotary blade 4A presses the anchor A to cut the anchor A.
As described above with reference to FIG. 3, when the anchor A is cut, the anchor A is exposed from the single tube 11 (21) at the position where the cutting device 4 is arranged.

As the cutting device 4, a configuration other than that shown in FIG. 5 can be adopted.
For example, in the cutting device 4-1 shown in FIG. 6, a cutter ring 4-1A is used instead of the rotary blade 4A of the cutting device 4 of FIG. In FIG. 6, the cutting device 4-1 supports the motor 4-1C, the motor 4-1C, and the cutter ring 4-1A that rotationally drive the cutter ring 4-1A together with the cutter ring 4-1A, and the operation handle 4-. It has a main body portion 4-1B and a mounting portion 4-1F provided with 1D, and the mounting portion 4-1F rotatably supports the main body portion 4-1B by a rotation shaft 4-1E. Then, the cutting device 4-1 is attached to the guide rail 2A of the excavating device 1 by the mounting portion 4-1F.
When cutting the anchor A, the operation handle 4-1D of the main body 4-1B is operated, the cutter ring 4-1A is brought close to the anchor A, and the anchor A is pressed by the cutter ring 4-1A. A and the tension material AT are cut.
As described above with reference to FIG. 3, when the anchor A is cut, the anchor A is exposed from the single tube 11 (21) at the position where the cutting device 4-1 is arranged.

Alternatively, the anchor A and the tension material AT may be cut using a chainsaw 4-2A (or a wire saw) as in the cutting device 4-2 shown in FIG. 7.
The cutting device 4-2 of FIG. 7 has a main body 4-2C including a drive device for a chainsaw 4-2A (or a wire saw), an operation handle 4-2B fixed to the main body 4-2C, and a main body 4-2C. Has a mounting portion 4-2E that is rotatably supported by a rotating shaft 4-2D. Then, the cutting device 4-2 is attached to the guide rail 2A of the excavating device 1 by the attachment portion 4-2E.
When cutting the anchor A, the operation handle 4-2B is operated, the chainsaw 4-2A is close to the anchor A, and the chainsaw 4-2A presses the anchor A to cut the anchor A and the tension material AT. .. Press and cut.
As described above with reference to FIG. 3, when the anchor A is cut, the anchor A is exposed from the single tube 11 (21) at the position where the cutting device 4-2 is arranged.

According to the embodiment of FIGS. 1 to 7, the tension material AT composed of the anchor A and the PC steel stranded wire drawn from the ground side along the excavator 1 is placed at an arbitrary position on the ground side by the cutting device 4. Can be cut with. At the time of cutting, the anchor A and the tension material AT are cut by the cutting device 4 in a state of being exposed from the inside of the single tube 11 (21).
Therefore, even if the single pipe 11 (21) is not bent, the single pipe 11 (21) is separated from the single pipe adjacent to the underground side, the buried object (anchor A and the tension material AT) is cut, and the excavator 1 Can be safely discharged from.
Then, even the existing anchor A using the PC steel stranded wire as the tension material AT can be reliably cut by the cutting device 4.
Further, since it is sufficient that the stroke of the excavating device 1 is equal to the unit length of the single pipe 11 (21), it is not necessary to significantly modify the existing excavating device 1.

A first modification of the illustrated embodiment will be described with reference to FIGS. 9 and 10.
In FIGS. 9 and 10, the tip bit 13 of the first modification and the underground cutting mechanism 14 for cutting the anchor A are shown.
9 and 10 show a tip member 12 connected to the underground tip of a single pipe 11 (hollow pipe) (not shown). The tip member 12 has a tip bit 13, an underground cutting mechanism 14, and a main body 15.
In FIGS. 9 and 10, the main body 15 includes an inner pipe 15A and an outer pipe 15B. Although not clearly shown, the inner tube 15A is connected to the single tube 11 on the ground side (right side in FIGS. 9 and 10) from the positions shown in FIGS. 9 and 10, and the rotation of the single tube 11 is rotated by the tip bit. It is transmitted to 13. The inner pipe 15A is configured as a hollow pipe, and an anchor A to be removed (see FIG. 8:, for example, a ground anchor using a PC steel stranded wire as a pulling material) penetrates through the hollow portion inside the hollow pipe. are doing.

The outer pipe 15B of the main body 15 is arranged outward in the radial direction of the inner pipe 15A, and the inner pipe 15A and the outer pipe 15B are screwed by a right-handed screw (reverse screw) 15C (screwed portion 15C).
The inner tube 15A rotates integrally with the single tube 11. When the underground cutting mechanism 14 is operated, when the single pipe 11 is reversed and the inner pipe 15A is reversed, the outer pipe 15B is moved to the underground side with respect to the inner pipe 15A by the action of the reverse screw 15C (in FIG. 9). Move relative to the left side).
The pull-out / rotation stop pins 15D are arranged at a plurality of locations (2 to 4 locations) in the circumferential direction of the inner peripheral surface of the outer pipe 15B. In FIG. 9 (during the covering digging process), the pin 15D abuts on the protruding portion 15AA formed on the outer peripheral surface of the inner pipe 15A, so that even if the single pipe 11 and the inner pipe 15A rotate in the normal direction, the outer pipe 15B is on the ground. It is prevented from coming off to the side (right side in FIGS. 9 and 10).

On the outer peripheral surface of the inner pipe 15A, a guide groove 15AB is formed on the underground side (left side in FIGS. 9 and 10) of the protruding portion 15AA, and the guide groove 15AB passes through the guide groove 15AB and the rotation stop pin 15D moves.
An inclined step portion 15BA is formed near the tip of the outer pipe 15B on the underground side (left side in FIGS. 9 and 10), and is outside on the underground side (left side in FIGS. 9 and 10) from the inclined step portion 15BA. The outer peripheral portion of the hollow member 14A of the underground cutting mechanism 14 is fitted to the inner peripheral portion of the pipe 15B.
The inclined step portion 15BA of the outer pipe 15B is in contact with the ground side end portion in the outer portion of the hollow member 14A. When the underground cutting mechanism 14 is operated, the hollow member 14A is pressed by the inclined step portion 15BA and moves to the underground side (arrow X in FIG. 10: left side in FIG. 10) in the axial direction.

The underground cutting mechanism 14 includes a hollow member 14A and a cutter 14B (cutting member).
The inner peripheral surface of the hollow member 14A is formed in a hollow cylindrical shape constituting the hollow member side engaging portion 14AA, and the outer peripheral portion thereof is fitted to the outer pipe 15B of the main body portion 15 as described above. As is clearly shown in FIGS. 9 and 10, the hollow member side engaging portion 14AA has a large inner diameter on the cutter 14B side (underground side: left side in FIGS. 9 and 10), and is separated from the cutter 14B (as it is separated from the cutter 14B). It is formed so that the inner diameter dimension becomes smaller (to the ground side or to the right side of FIGS. 9 and 10).
The cutter 14B has a scissors shape as a whole, and includes an upper cutter 14BA and a lower cutter 14BB. The upper cutter 14BA and the lower cutter 14BB are pivotally supported on the main body 15 side by the cutter pins 14C, respectively. Curved cutter side engaging portions 14BAA and 14BBA are formed on the outer surface near the end of the upper cutter 14BA and the lower cutter 14BB on the ground side (right side in FIGS. 9 and 10), and the curved cutter side engagement portion is formed. The hollow member side engaging portion 14AA can slide on the joint portions 14BAA and 14BBA while pressing.
Cutting blades 14BC are provided near the tips of the upper cutter 14BA and the lower cutter 14BB on the ground side (right side in FIGS. 9 and 10), respectively, and the cutting blade 14BC constitutes the underground side cutting mechanism 14. Here, the cutting blade 14BC is made of a cemented carbide tip, and can reliably cut the anchor A having a PC steel stranded wire.
As shown in FIG. 9, the hollow portion of the hollow member 14A and the inside of the cutter 14B in the radial direction are configured so that the anchor A to be cut can penetrate.

When the upper cutter 14BA and the lower cutter 14BB are pivotally supported on the main body 15 side, the cutting blade 14BC is held in an open state (state in FIG. 9) by an elastic urging means (for example, a snap ring) (not shown). ..
When cutting by the underground side cutting mechanism 14, the curved cutter side engagement formed on the outer surface near the ground side (right side in FIGS. 9 and 10) ends of the cutter 14B (upper cutter 14BA, lower cutter 14BB). The hollow member side engaging portion 14AA formed on the inner peripheral surface of the hollow member 14A moving to the underground side (left side in FIGS. 9 and 10) presses on the portions 14BAA and 14BBA while sliding. Then, as a result of the hollow member side engaging portion 14AA sliding and pressing on the cutter side engaging portions 14BAA and 14BBA, the upper cutter 14BA and the lower cutter 14BB have the cutter pin 14C as an axis against the elastic urging means. (Arrow Y in FIG. 10), the above-ground side (right side in FIGS. 9 and 10) of the upper cutter 14BA and the lower cutter 14BB move inward in the radial direction (arrow Z in FIG. 10). The underground cutting mechanism 14 by the cutting blade 14BC is closed.

The tip bit 13 is formed in a hollow circular tube, and an opening 13A through which the anchor A to be removed penetrates is formed inside.
A plurality of excavation tips T are arranged in the circumferential direction near the tip of the tip bit 13 on the underground side (left side of FIGS. 9 and 10), and the tip bit 13 is located on the ground side of the tip bit 13 (FIGS. 9 and 10). The right end surface constitutes a curved surface 13C (FIG. 9) on which the underground side (left side of FIGS. 9 and 10) ends of the cutter 14B slide.
Although not clearly shown, the tip bit 13 is connected to the inner pipe 15A of the main body portion 15, and the normal rotation of the single pipe 11 is transmitted to the tip bit 13 via the main body portion 15 and the underground cutting mechanism 14. ..

Next, a mode in which the anchor A is cut and removed by the existing anti-removal device 10 of the first modification will be described.
As shown in FIG. 9, in the cover digging step of digging along the anchor A (FIG. 8), the single pipe 11 (not shown in FIG. 9) is rotated in the normal direction, and the ground around the anchor A is formed by the tip bit 13 of the tip member 12. Or excavate the soil. As a result, as shown in FIG. 8, the anchor A has the tip bit 13, the underground cutting mechanism 14, the main body 15 (inner pipe 15A), and the hollow of the single pipe 11 in a state where the surrounding ground is excavated. The inside of the part is extended to the ground side.
When excavated to a predetermined depth, or when the drilling direction of the cover digging and the anchor extension direction deviate from each other as shown in FIG. 8, the anchor A is cut.

When cutting the anchor A, first, the tip bit 13 of the tip member 12 is pressed against the ground side. By pressing the tip bit 13 to the ground side, the excavation tip T of the tip bit 13 bites into the ground, so that the tip bit 13 is fixed without rotating.
The single tube 11 is rotated in the reverse direction while the tip bit 13 is fixed without rotating. The inner pipe 15A of the main body 15 rotates in the normal direction integrally with the single pipe 11, but when the single pipe 11 is rotated in the reverse direction, the outer pipe 15B becomes the inner pipe 15A (single pipe) due to the action of the reverse screw of the screwed portion 15C. 11) Moves relative to the underground side (left side in FIGS. 9 and 10), and as shown in FIG. 10, the pin 15D is located near the end of the guide groove 15AB on the underground side (left side in FIG. 10). Move to.
When the single pipe 11 rotates in the reverse direction and the outer pipe 15B moves to the underground side (left side in FIG. 10), the hollow member 14A is pressed toward the ground by the inclined step portion 15BA of the outer pipe 15B, and the hollow member 14A is hollow. The member 14A also moves to the underground side in the axial direction (arrow X in FIG. 10).
When the hollow member 14A is pressed toward the ground side, the cutter 14B (upper cutter 14BA, lower cutter 14BB) of the underground side cutting mechanism 14 is pressed by the hollow member side engaging portion 14AA of the hollow member 14A, and the upper cutter 14BA, The lower cutter 14BB rotates in the direction of arrow Y in FIG. 10 around the cutter pin 14C against the elastic urging means, and the pair of cutting blades 14BC move inward in the radial direction (arrow Z in FIG. 10). .. The upper cutter 14BA and the lower cutter 14BB rotate in the direction of the arrow Y in FIG. 10, and the pair of cutting blades 14BC move in the direction of the arrow Z in FIG. 10, whereby the anchor A (not shown) is cut.
Here, FIG. 10 shows a state in which the underground cutting mechanism 14 is blocked by the pair of cutting blades 14BC of the cutter 14B.

After cutting the anchor A, in the state of FIG. 10, when the state in which the tip bit 13 is pressed against the ground is released and the single tube 11 is pulled up to the ground side, the cut piece of the cut anchor A is pulled up to the ground side. Can be done. In the state of FIG. 10, since the cutter 14B is in the closed state, the cut piece of the anchor A does not fall into the ground even if the single tube 11 is pulled up, and the cut piece does not remain in the ground and is not left on the ground. It can be pulled up to the side and the cut piece can be discharged on the ground side.

In the removal device 10 according to the first modification shown in FIGS. 9 and 10, since the cutting blade 14BC of the cutter 14B is composed of a cemented carbide tip, even if the tensile material is a PC steel stranded wire, the anchor A is used. It can be cut reliably.
Then, when cutting the anchor A, the anchor A is desired by an extremely simple operation of pressing the underground tip (excavation tip T) of the tip bit 13 against the ground to fix it and reversing the single pipe 11. It can be cut reliably at the location of. Then, since the anchor A can be easily cut by reversing the single pipe 11, the anchor A is cut piece by piece by so-called "single pipe excavation" using the single pipe 11 which is a single hollow pipe. It is possible to cut it into pieces and discharge it on the ground side.
After cutting the anchor A (existing resistance), by pulling up the single pipe 11 to the ground side, the cut existing anchor A can be discharged to the ground side for each cut piece and removed from the ground. At that time, since the underground side cutting mechanism 14 (cutter 14B) is in a closed state, the cut piece of the anchor A does not fall and remain in the ground even if the single tube 11 is pulled up.
Further, in the first modification shown in FIGS. 9 and 10, the space penetrating the anchor A in the inner pipe 15A, the outer pipe 15B, and the underground cutting mechanism 14 and the strength (thickness) of the member are secured, and the anchor It is not necessary to offset A from the central axis of the single tube 11.

Next, a second modification of the illustrated embodiment will be described with reference to FIGS. 11 to 19. The second modification has an underground cutting mechanism 24 that is different from the underground cutting mechanism 14 of the first modification.
In FIG. 11, the tip member according to the second modification is indicated by reference numeral 22, and has a tip bit 23 and a bit body 25.
A plurality of (9 in FIG. 11) excavation tips T are arranged at the tip (ground tip) of the tip bit 23. The center of the tip bit 23 and the center of the internal space 23S of the tip bit 23 are eccentric. Here, the internal space 23S is a space in which the anchor A is inserted at the time of covering and digging. Here, the space or opening in which the cutting blade 23B (FIGS. 12 and 13) on the tip bit side is arranged is indicated by reference numeral 23A.
Although not explicitly shown in FIG. 11, an underground cutting mechanism 24 (not shown) is arranged inside the bit body 25.

12 and 13 show the entire tip member 22 connected to the tip of a single pipe 21 (hollow pipe) (not shown) on the underground side (left side in FIGS. 12 and 13). The tip member 22 has a tip bit 23, a bit body 25, and an underground cutting mechanism 24.
The hollow cylindrical bit body 25 has a ground side (right side in FIGS. 12 and 13) end connected to a single tube 21 (not shown in FIGS. 12 and 13) and is integrated with the single tube 21. Rotate to.
An accommodating portion 25A is formed near the tip of the bit body 25 on the underground side (left side in FIG. 12), and the accommodating portion 25A is configured as an enlarged diameter hollow portion. In the accommodating portion 25A, the above-ground side portion of the tip bit 23 is arranged in the underground side portion thereof.
The tip bit 23 is rotatable relative to the bit body 25. Further, the tip bit 23 is connected by a fixing pin 27 so as not to be separated from the bit body 25.
A cutting jig 24A is arranged adjacent to the tip bit 23 at the ground side (right side in FIG. 12) end of the accommodating portion 25A. The cutting jig 24A is fixed to the bit body 25 by means (not shown) and rotates at the same time as the single tube 21.

The tip bit 23 is formed in a hollow cylindrical shape, and a plurality of excavation tips T are arranged along the circumferential direction at the tip on the underground side (the left end in FIGS. 12 and 13). The tip bit side cutting blade 23B is provided so as to project inward in the radial direction at the inner peripheral portion of the opening 23A (internal space) near the ground side end portion (right side in FIGS. 12 and 13) of the tip bit 23. There is. The cutting blade 23B rotates integrally with the tip bit 23.
A cutting jig 24B on the cutting jig side is provided on the inner peripheral portion of the opening 24AA (internal space) of the cutting jig 24A so as to project inward in the radial direction, and the cutting jig 24B is provided with a cutting jig. The rotation of the single tube 21 is transmitted via 24A and the bit body 25.
The underground side cutting mechanism 24 in the second modification is configured by the cutting jig side cutting blade 24B provided on the cutting jig 24A and the tip bit side cutting blade 23B provided on the tip bit 23. Here, the cutting blades 23B and 24B are made of cemented carbide chips, and even if the tension material is the anchor A made of stranded PC steel, it can be reliably cut.

As shown in FIG. 12, the tip bit side cutting blade 23B and the cutting jig side cutting blade 24B are arranged adjacent to each other in the axial direction, and the rotation center axes of the two cutting blades 23B and 24B are in the same straight line. It is configured like this.
During digging, the single tube 21 rotates in the forward direction, and both cutting blades 23B and 24B are maintained at the same position in the circumferential direction (state in FIG. 12), and the rotation of the single tube 21 is the bit body 25 and the cutting jig 24A. Is transmitted to the tip bit 23 via.
On the other hand, when cutting the anchor A, the tip bit 23 is fixed so as not to rotate, the single tube 21 is reversed, and the bit body 25 and the cutting jig 24A are also reversed, so that the cutting blades 23B and 24B are cut. Is relatively rotated to bring the relative position to the state shown in FIG.
Refer to FIGS. 18 and 19 for the mechanism of maintaining the cutting blades 23B and 24B in the state of FIG. 12 and rotating them in the normal direction and the mechanism of rotating the cutting blades 23B and 24B relative to each other to bring them into the state of FIG. Will be described later.

In the tip bit 23, the opening 23A is a space in which the anchor A is inserted and the cutting blade 23B is arranged, and is a portion other than the cutting blade 23B. In the cutting jig 24A, the opening 24AA is a space in which the anchor A is inserted and is a portion other than the cutting blade 24B. The cross-sectional shape of the opening 23A and the opening 24AA or the shape of the arrow A1 in FIG. 12 is substantially circular. If the cross-sectional shape of the opening 23A and the opening 24AA or the shape of the arrow A1 in FIG. 12 is a non-circular shape such as a triangle, a quadrangle, or a semicircle, the inner diameter of the space through which the anchor A is passed must be increased. This is because the diameter of the tip bit 23, the cutting jig 24A, and the bit body 25 and the diameter of the boring hole must be increased accordingly.
As will be described in FIGS. 14 and 14, the center of the tip bit 23 (that is, the rotation axis of the single tube 21) and the center of the opening 23A are eccentric. By eccentricity, the outer diameter dimension (vertical dimension in FIGS. 12 and 13) of the tip bit 23 is reduced. Similarly, the center of the bit body 25 (that is, the rotation axis of the single tube 21) and the center of the opening 24AA of the cutting jig 24A are eccentric.
Although not shown, if the center of the bit body 25 (that is, the axis of rotation of the single tube 21) and the center of the opening 24AA of the cutting jig 24A are eccentric, the center of the tip bit 23 (that is, the single tube) It is also possible not to eccentricize the rotation axis of 21) and the center of the opening 23A.

Next, the operation of the second modification shown in FIGS. 11 to 13 is schematically performed with reference to FIGS. 14 to 19 which schematically show the shapes of the cutting blades 23B and 24B (the shape of the arrow A1 in FIG. 12). To explain.
The positional relationship between the opening 23A and the cutting blade 23B in the tip bit 23 is shown in FIG. 14 (1), and the positional relationship between the opening 24AA and the cutting blade 24B in the cutting jig 24A is shown in FIG. 14 (2). Has been done.
FIG. 15, which shows the relative positions of the tip bit 23 and the cutting jig 24A in the state of FIG. 12 with arrow A1, shows the state at the time of cover digging in which the single tube 21 is rotated in the forward direction. In FIG. 15, the tip bit side cutting blade 23B and the cutting jig side cutting blade 24B are held at the same position in the circumferential direction.
As described above, the rotation of the single tube 21 (FIG. 8) is transmitted to the tip bit 23 via the bit body 25 (FIG. 12) and the cutting jig 24A (underground cutting mechanism 24). The anchor A to be cut is inserted inside the opening 23A of the tip bit 23 and the opening 24A of the cutting jig 24A.

When cutting the anchor A, the tip bit 23 is pushed into the ground side (left side in FIG. 12), and the excavation tip T arranged at the tip of the tip bit 23 is made to bite into the ground being excavated to bite the tip bit. Fix 23 so that it does not rotate. After fixing the tip bit 23, the single tube 21 is reversed and the cutting jig 24A is also reversed, so that the cutting jig side cutting blade 24B rotates relative to the tip bit side cutting blade 23B.
FIG. 16 shows a process of rotating the cutting jig 24A relative to the tip bit 23, and the cutting jig 24A (and the cutting blade 24B) is rotated by 90 ° relative to the state of FIG. There is.
FIG. 17 shows a state in which the cutting jig 24A is further rotated 90 ° relative to the tip bit 23 from the state shown in FIG. 16 (180 ° relative rotation from the state shown in FIG. 15) to complete the cutting of the anchor A. Is shown, and corresponds to the state shown in FIG.
In the state of FIG. 17, the opening 23A (and the opening 24AA of the cutting jig 24A) in the tip bit 23 is closed by the tip bit side cutting blade 23B and the cutting jig side cutting blade 24B. Therefore, the anchor A (not shown in FIGS. 17 and 13) inserted into the opening 23A and the opening 24AA is cut by the tip bit side cutting blade 23B and the cutting jig side cutting blade 24B.

Next, with reference to FIGS. 18 and 19, a mechanism for maintaining the tip bit side cutting blade 23B and the cutting jig side cutting blade 24B in the state shown in FIG. 12 and rotating them in the normal direction, and the cutting blades 23B and 24B are predetermined. A mechanism for relative rotation within a range will be described.
Although not explicitly shown in FIGS. 12 and 13, as shown in FIGS. 18 and 19, the cutting jig 24A protrudes toward the tip bit 23 (the viewer side in FIGS. 18 and 19). A portion 24AB is provided, and a first jig side step portion 24AB1 and a second jig side step portion 24AB2 are formed at both ends in the circumferential direction of the jig side protrusion 24AB.
On the other hand, the tip bit 23 has a tip bit side protruding portion 23C protruding toward the cutting jig 24A side (opposite side to the viewer side in FIGS. 18 and 19), and the circumference of the tip bit side protruding portion 23C. A first tip bit side step portion 23C1 and a second tip bit side step portion 23C2 are formed at both ends in the direction.
The first jig side step portion 24AB1 of the jig side projecting portion 24AB can abut on the first tip bit side step portion 23C1 of the tip bit side projecting portion 23C (state of FIG. 18: FIGS. 12, 15). The second jig side step portion 24AB2 of the jig side projecting portion 24AB can abut on the second tip bit side step portion 23C2 of the tip bit side projecting portion 23C (corresponding to the covering digging process shown by). State of 19: Corresponds to the state in which the cutting of the anchors of FIGS. 13 and 17 is completed). Therefore, when the tip bit 23 is pushed into the ground (left side in FIG. 12) and fixed so that the tip bit 23 does not rotate, the cutting jig 24A changes from the state shown in FIG. 18 to the state shown in FIG. 19, that is, Only the range (predetermined range) of the reference numeral R in FIG. 18 can be rotated.

During the cover digging step of digging the peripheral region of the anchor A, the cutting jig 24A connected to the single pipe 21 (see FIG. 8) via the bit body 25 (see FIG. 12) rotates in the normal direction. In FIGS. 18 and 19 seen from the underground side, the cutting jig 24A rotates counterclockwise. As shown in FIG. 18, the first jig side step portion 24AB1 of the jig side protrusion 24AB abuts and presses against the first bit side step portion 23C1 of the bit side protrusion 23C, and the tip bit 23 is also positive. Turn (counterclockwise in FIG. 18). When the tip bit 23 rotates in the normal direction, the area around the anchor A is excavated by the excavation tip T.
In the state shown in FIG. 18, that is, in the cover digging step of excavating the peripheral region of the anchor A, the relative positions of the tip bit 23 and the cutting jig 24A are as shown in FIG. 15 (FIG. 12), and the tip bit 23, Both the cutting jigs 24A rotate in the forward direction to maintain the state shown in FIG. 15 (FIG. 12). In the state shown in FIG. 18 (or the state of FIGS. 15 and 12), the position of the opening 23A at the position where the tip bit side cutting blade 23B is arranged and the position where the cutting jig side cutting blade 24B is arranged. The positions of the openings 24AA are aligned, and the anchor A penetrates the aligned openings 23A and 24AA.

In the step of cutting the anchor A, the tip bit 23 is pushed into the ground side, and the excavation tip T arranged at the tip of the tip bit 23 on the ground side is made to bite into the ground. As a result of the excavation tip T biting into the ground, the tip bit 23 is fixed in a non-rotating state.
When the single tube 21 is reversed in this state, the cutting jig 24A rotates clockwise in FIG. 18 as seen from the underground side.
As described above, the bit body 25 (cutting jig 24A) can rotate relative to the tip bit 23 only within a predetermined range (the range indicated by the arrow R in FIG. 18). That is, when the cutting jig 24A is reversed, the range until the second jig side step portion 24AB2 of the jig side protruding portion 24AB comes into contact with the second bit side step portion 23C2 of the tip bit side protruding portion 23C. Up to the range of R, the cutting jig 24A rotates (reverses) relative to the tip bit 23.
As a result, the relative positions of the tip bit 23 and the cutting jig 24A pass through the state shown in FIG. 16 and become the state shown in FIG. 17, during which the tip bit side cutting blade 23B and the cutting jig side cutting blade The anchor A is cut by 24B (state in FIG. 19). In FIG. 19, the portion where the tip bit side cutting blade 23B and the cutting jig side cutting blade 24B overlap is shown in white.
Then, since the anchor A can be easily cut by reversing the single pipe 21, the anchor A is cut piece by piece by so-called "single pipe excavation" using the single pipe 21 which is a single hollow pipe. It can be cut into pieces and discharged on the ground side.

After cutting the anchor A, if the single tube 21 is pulled up to the ground side in the state of FIG. 19, the cut piece of the cut anchor A can be pulled up to the ground side.
In the state of FIG. 19, the positions of the opening 23A of the tip bit 23 and the opening 24AA of the cutting jig 24A do not overlap, and as shown in FIG. 19, the cutting blade 23B on the tip bit side and the cutting jig It is closed by the side cutting blade 24B. Therefore, when the single tube 21 is pulled up to the ground side, the cutting piece of the anchor A is supported by the cutting blade 23B on the tip bit side and the cutting blade 24B on the cutting jig side, and does not fall or remain in the ground and is on the ground side. Will be pulled up to. Then, it can be discharged on the ground side in a known manner.

According to the removal device 20 according to the second modification described with reference to FIGS. 11 to 19, the center of the tip bit 23 and the center of the opening 23A are eccentric, and the center of the bit body 25 and the cutting jig 24A Since the center of the opening 24AA is eccentric, the outer diameter of the tip bit 23 can be reduced.
Other configurations and actions and effects in the second modification are the same as those in the first modification of FIGS. 9 and 10.

According to the illustrated embodiment, the existing anchor A can be easily and surely cut at a desired position on the ground side by using the cutting device 4. If the underground cutting mechanism 14 or 24 is used, the anchor A can be easily and surely cut at a desired position not only on the ground side but also in the underground side region. In other words, the anchor A can be cut at a desired position on both the underground side and the ground side.
Further, in the illustrated embodiment, if the anchor A is cut on the ground side using the cutting device 4, for example, to be equal to or less than the length of the casing (single pipes 11 and 21), the anchor is anchored by the underground side cutting mechanism 14 or 24. Anchor A can be easily and safely removed without cutting A in the ground.
On the other hand, if the anchor A is cut to, for example, the length of the casing (single pipes 11 and 21) or less by the underground side cutting mechanism 14 or 24, the anchor A does not need to be cut by the cutting device on the ground side. Can be easily and safely removed.
Whether the existing anchor A is cut only on the ground, only in the ground, or both on the ground and in the ground depends on the length of the anchor A (or the reach depth of the anchor A) and the construction site. It is possible to select in consideration of various conditions. In other words, by using the underground cutting mechanism 14 or 24 in the illustrated embodiment, the optimum construction method is selected in consideration of the length (or reach depth) of the anchor A and various conditions at the construction site. It becomes possible.

It should be added that the illustrated embodiment is merely an example and is not a description to the effect of limiting the technical scope of the present invention.
For example, although the illustrated embodiment is applied in the case of single-tube drilling, the present invention is also applicable in the case of double-tube drilling.
Further, the cutting device 4 on the ground side and the cutting mechanism 14 or 24 on the underground side are also examples, and a buried object (for example, an existing anchor A) may be cut in the ground by another structure.
Further, in the illustrated embodiment, the existing anchor A, which is a buried object, is covered and dug, and the existing anchor A is exposed and cut on the guide rail on the ground side, but the object to be cut other than the existing anchor A is cut. Can be applied to. In addition to that, although the cutting device 4 is provided in the removing devices 10 and 20, it is possible to arrange the cutting device 4 in addition to the removing devices 10 and 20 to cut the object to be cut.

1 ... Excavation device 2 ... Head 2A ... Guide rail 4 ... Cutting device (ground side cutting device)
10, 20 ... Removal device 11, 21 ... Single tube (hollow tube)
13, 23 ... Tip bit 14, 24 ... Underground side cutting mechanism 14A ... Hollow member 14B ... Cutting member (cutter)
24A ... Cutting jigs 23B, 24B ... Cutting blades A ... Buried objects

Claims (6)

In the removal device that cuts and removes the anchor
An excavator is installed on the ground side,
A cutting device, guide rail, drive device and swivel are excavated to separate the hollow pipe for each unit length, expose the anchor entering the inside of the hollow pipe on the ground side, and cut the anchor at the exposed part. Installed in the device
The cutting device is arranged on a guide rail and has a function of cutting an anchor that has entered the inside of a hollow pipe that moves along the guide rail.
The guide rail has a function of moving a hollow pipe along the guide rail.
Anchors to be cut can enter the hollow tube inward.
The swivel is a removal device characterized by having a function of rotating in a direction of releasing screwing between hollow tubes . In the removal device that cuts and removes the anchor
It is equipped with a guide rail, a hollow tube in which hollow tubes of unit length are screwed together, and a swivel that has the function of rotating in the direction of releasing the screwing between the hollow tubes.
The guide rail has a function of moving a hollow pipe along the guide rail.
Anchors to be cut can enter the hollow portion of the hollow tube.
The main body is connected to the tip of the hollow tube on the underground side, and the underground cutting mechanism having a function of cutting the anchor in the ground is connected to the main body.
The underground cutting mechanism is provided on the underground side of the hollow pipe, and when rotated in a direction of unscrewing the hollow pipe by a swivel, it moves relative to the hollow pipe and of the hollow pipe. Removal characterized by having a hollow member provided at the tip of the ground side that advances to the tip bit side and a cutting member that moves inward in the radial direction and cuts the anchor when the hollow member advances to the tip bit side. Device. In the removal device that cuts and removes the anchor
It is equipped with a guide rail, a hollow tube in which hollow tubes of unit length are screwed together, and a swivel that has the function of rotating in the direction of releasing the screwing between the hollow tubes.
The guide rail has a function of moving a hollow pipe along the guide rail.
Anchors to be cut can enter the hollow portion of the hollow tube.
A bit body is connected to the underground tip of the hollow tube, a tip bit is provided on the underground side of the bit body, the bit body has an opening and a hollow portion, and the anchor is cut in the ground. Has an underground cutting mechanism
The underground cutting mechanism includes a cutting blade on the tip bit side provided on the inner peripheral portion of the opening of the bit body, and a cutting jig arranged on the ground side of the hollow portion of the bit body and having an opening. And, it has a cutting tool side cutting blade provided on the inner peripheral portion of the opening of the cutting jig, and the center of the opening of the tip bit and the center of the opening of the jig are hollow tubes. When the cutting jig is rotated relative to the tip bit, the cutting blade on the tip bit side and the cutting blade on the cutting jig side rotate relatively to the tip. A removal device characterized by having the function of closing the opening of the bit and cutting the anchor. In the removal method using the removal device of claim 1,
The process of allowing the anchor to be cut to enter the inside of the hollow pipe through the opening of the hollow pipe that moves along the guide rail provided in the excavator of the removal device.
It has a process of cutting the anchor that has entered the inside of the hollow tube.
The cutting step is
The process of separating the hollow pipe for each unit length and exposing the anchor that has entered the inside of the hollow pipe on the ground side,
A removal method comprising a step of cutting an anchor at an exposed portion on the ground side by a cutting device arranged on a guide rail of the removing device. In the removal method using the removal device of claim 2,
The process of allowing the anchor to be cut from the opening of the hollow pipe to enter the inside of the hollow pipe,
It has a process of cutting the anchor that has entered the inside of the hollow pipe in the ground by the underground cutting mechanism.
In the cutting step, the hollow tube is rotated in a direction of unscrewing by a swivel, and the hollow member provided on the underground side of the hollow tube is moved relative to the hollow tube to move the hollow tube. A removal method characterized by advancing to the tip bit side provided at the tip of the underground side and moving the cutting member of the underground cutting mechanism inward in the radial direction of the anchor to cut the anchor . In the removal method using the removal device of claim 3,
The process of inserting the anchor to be cut from the opening of the hollow tube of the removal device into the hollow tube, and
It has a process of cutting the anchor that has entered the inside of the hollow pipe on the underground side by the underground side cutting mechanism.
In the cutting step, the swivel is used to rotate the hollow tube in the direction of unscrewing, rotate the cutting jig in that direction, and rotate the cutting jig relative to the tip bit to rotate the tip bit. A removal method characterized by relatively rotating the side cutting blade and the cutting jig side cutting blade to close the opening in the tip bit and cutting the anchor.

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