JP2016053279A - Removing device and removing method for removing existing anchor from ground - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a removing device and removing method in which long buried object, such as an existing anchor, is cut into a desired length and the buried object is removed from ground with a simple structure.SOLUTION: A removing device 10 comprises: an inner tube 11, an outer tube 12, a cutting arm 13, a projecting part 14, a swivel 15 and a lock mechanism 16. The inner tube 11 digs a periphery of an existing anchor. The outer tube 12 is equipped on an outside of the inner tube 11 and digs a periphery of the inner tube 11. An end part of the cutting arm 13 is engaged on a near part of a tip end part of the inner tube 11 in a pivotable manner and comprises a blade cutting the anchor at a tip end part extending to a rear side in a rotating direction of the inner tube 11. The projecting part 14 is arranged on the outer tube 12 at a corresponding position to the cutting arm 13 and pushes the cutting arm 13 toward the central axis of the anchor by rotation of the outer tube 12 in the rotating direction prior to the inner tube 11.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a removal device and a removal method for removing a pile and an anchor used for preventing a landslide on a slope, remodeling the ground, or a foundation of a building from the ground.

  Due to the rebuilding of the building and the replacement work due to aging, existing piles buried in the foundation of the building and existing anchors installed on the slope must be removed.

  According to the drawing device described in Patent Document 1, a second cylindrical member provided with a blade for excavating a surrounding region of an existing pile at the tip, and an inner side of the second cylindrical member so as to be rotatable by a certain angle. The 1st cylindrical member with which it attached to is provided. Three supports are swingably attached to the first tubular member by a support shaft, and extend downstream in the rotational direction when the second tubular member is rotated in the excavation direction. The pressed portion that extends opposite to the support body with respect to the support shaft is engaged with an opening provided in the second cylindrical member. When the second cylindrical member rotates in the excavation direction, the support body is positioned at a retracted position that does not interfere with the pile along the inner periphery of the first cylindrical member, and the second cylindrical member rotates in the direction opposite to the excavation direction. In this case, the support body is pushed by the rotation direction pressing portion of the opening and rotates toward the center of the second cylindrical member. When the support reaches a position deeper than the lower end of the existing pile, the pulling device rotates the second tubular member in the direction opposite to the excavation direction, so that the second tubular member is relatively positioned. One cylindrical member is rotated. The support is rotated toward the center of the existing pile and is located below the existing pile. The existing pile is pulled up by pulling out the second cylindrical member from the soil.

  According to the existing pile removal apparatus described in Patent Document 2, a cylindrical casing having a drilling blade for digging the periphery of the existing pile, and a cutting blade provided so as to be able to protrude and retract from the inner surface at the tip of the casing And a hydraulic device for projecting and retracting the cutting blade. As the cutting blades, there are a pair of reinforcing bar cutting blades for cutting the reinforcing bars of the existing piles and a pair of concrete cutting blades for breaking the concrete of the existing piles symmetrically with respect to the center of the casing. This existing pile removing apparatus digs up the surroundings of the existing piles to a predetermined depth, and then cuts the reinforcing bars embedded around the piles by protruding the reinforcing bar cutting blades with a hydraulic device. When the rebar is cut, the rebar cutting blade is accommodated by the hydraulic device, the concrete cutting blade is protruded, and the existing pile is completely cut. A part of the cut existing pile is hooked with a protruding concrete cutting blade, and the whole casing is lifted and discharged. By repeating the above steps, the existing pile is completely removed by dividing into predetermined lengths.

JP-A-2005-61158 JP 2006-28878 A

  According to the apparatus described in Patent Document 1, although the structure is simple, it must be dug down to a depth exceeding the lower end of the existing pile. Therefore, in order to pull out a long pile or anchor from the soil, a cylindrical member that is longer by that amount is required. And when the case where it has to be divided on the way in order to discharge the existing pile which was pulled out arises, work will become complicated. Furthermore, since the protrusion amount of a support body cannot be adjusted, it is unsuitable for cut | disconnecting the reinforcing bar of a pile. In particular, since the anchor often includes a reinforcing bar and a steel wire to the center, it is difficult to obtain a sufficient cutting force with the support extended by the lever principle.

  Moreover, according to the apparatus described in Patent Document 2, it has a reinforcing bar cutting blade exclusively and has a structure that is fed out by a hydraulic device, but each cutting blade is provided with a hydraulic cylinder. Therefore, a hydraulic path for supplying oil to the hydraulic cylinder is required, which is structurally complicated and requires a large apparatus.

  Therefore, the present invention provides a removal device and a removal method with a simple structure for cutting a long buried object such as an existing anchor to a desired length and removing the buried object from the ground.

  A removal device according to an embodiment of the present invention includes an inner tube, an outer tube, a cutting arm, a convex portion, a swivel, and a lock mechanism. The inner pipe rotates around an existing anchor and excavates the outer periphery. The outer pipe is attached to the outside of the inner pipe with a gap, and rotates to excavate the outer periphery of the inner pipe. The cutting arm has a blade that cuts an anchor at a distal end portion that is pivotally attached to the vicinity of the distal end portion of the inner tube and extends rearward in the rotation direction of the inner tube. The convex portion is provided on the outer tube at a position corresponding to the cutting arm, and pushes the cutting arm toward the center of the anchor by rotating the outer tube prior to the rotation direction with respect to the inner tube. The swivel has an inner spindle connected to the proximal end of the inner tube, and an outer spindle that covers the outside of the inner spindle and is connected to the proximal end of the outer tube. The lock mechanism is provided in the swivel and switches to a connected state in which the inner spindle is coupled to the outer spindle or a released state in which the inner spindle can be rotated with respect to the outer spindle.

  At this time, it is desirable to provide a plurality of cutting arms, specifically two or three, at equal intervals in the circumferential direction of the inner tube. The angle at which the cutting arm protrudes toward the center of the inner tube changes according to the rotation angle of the outer tube preceding the inner tube in the rotation direction with respect to the inner tube. The distal end portion of the cutting arm abuts on the outer peripheral surface of the anchor in a tangential direction while cutting the anchor. The blade at the tip of the cutting arm is disposed in a direction intersecting the outer peripheral surface of the anchor, and cuts the anchor so as to be pulled in the rotational direction. The outer tube has a support ring on the inner peripheral surface on the tip side of the convex portion, and the inner tube has a guide that comes into contact with the support ring from the base end side at a position where the cutting arm faces the convex portion. The swivel supplies circulating water for excavation to the inside of the inner pipe and the gap between the inner pipe and the outer pipe.

  Moreover, the removal method which removes the existing anchor from the ground using the above-mentioned removal apparatus includes a covering digging process, a cutting process, a recovery process, and a recovery process, and by repeating these several times in order, the existing anchor Is completely removed from the ground. In the cover digging step, a removal device that is connected to the swivel by a lock mechanism is placed on the ground end of the anchor, and the swivel is rotated to dig around the anchor. In the cutting process, after the swivel is released by the locking mechanism, the outer spindle is rotated at a certain depth, and the cutting arm is pushed out toward the center of the inner tube while rotating the inner tube, and the anchor is cut. . In the recovery step, the outer spindle is removed from the outer tube, and the fragments of the anchor cut by pulling up the swivel and inner tube are discharged to the ground while being supported by the cutting arm. In the recovery process, the inner tube is inserted into the outer tube, the outer spindle is connected to the proximal end portion of the outer tube, and the swivel is connected by the lock mechanism.

  According to the removal device of one embodiment according to the present invention, the cutting arm is provided near the tip of the inner tube, and the convex portion is provided on the outer tube at a position corresponding to the cutting arm. The inner tube and the outer tube are respectively connected to the inner spindle and the outer spindle of the swivel. The lock mechanism is switched to a released state in which the inner spindle and the outer spindle can be rotated relative to the connected state in which the inner spindle and the outer spindle are integrally coupled, and the outer pipe is rotated in the rotational direction rather than the inner pipe. The tip of the cutting arm is pushed out to the center by the convex part. The periphery of the existing anchor can be covered with this removal device, and the existing anchor can be cut to the desired length in the ground with a blade attached to the tip of the cutting arm and partially taken out. That is, it is not necessary to excavate the existing anchor that has been buried to the tip and extract it integrally. By cutting the existing anchors short and collecting them from the ground, the individual weights are reduced, so that the collected existing anchors can be handled easily.

  In addition, according to the removal device of the present invention in which a plurality of cutting arms are provided at equal intervals in the circumferential direction of the inner tube, the load applied to the blade at the tip of each cutting arm is reduced and the existing anchor is cut. In addition, since the load related to the anchor is equalized, the inner tube and the outer tube are not centered with respect to the existing anchor and are easily centered.

  According to the removal device of the present invention, the angle at which the cutting arm projects toward the center of the inner tube changes according to the rotation angle that the outer tube precedes in the rotation direction with respect to the inner tube in the connected state. It is easy to judge on the ground how much the existing anchor will be cut from the difference in rotation angle between the inner and outer tubes.

  While cutting the anchor, the tip of the cutting arm abuts tangentially with the outer peripheral surface of the anchor, and the blade is arranged at the tip of the cutting arm in a direction intersecting the outer peripheral surface of the anchor, and the rotation direction According to the removal device of the present invention that cuts the existing anchor so as to be pulled to the edge, the angle of the blade is kept constant with respect to the outer peripheral surface of the anchor. Therefore, until the anchor is cut, the load applied to the cutting arm is stabilized, and the cutting efficiency of the blade is also improved.

  The removal device of the present invention, in which the inner tube is provided with a guide that has a support ring on the inner periphery of the outer appearance on the distal end side than the convex portion, and that contacts the support ring from the proximal end side at a position where the cutting arm faces the protrusion. According to this, it is easy to position the cutting arm with respect to the convex portion.

  According to the removal device of the invention in which the swivel supplies circulating water for excavation to the inside of the inner tube and the gap between the inner tube and the outer tube, lubrication when excavating the outer periphery of the existing anchor and cutting the anchor In addition to cooling, it is possible to efficiently collect mud discharged when excavating the outer periphery of an existing anchor and chips generated when the anchor is cut.

  Moreover, according to the removal method of removing the existing anchor from the ground using the above-described removal device, the outer circumference of the existing anchor is excavated to a certain depth, and the anchor up to the excavated place is cut with a cutting arm and ground. Can be discharged. Since the portion up to the tip of the existing anchor is made into a fragment of a desired size and is taken out in a plurality of times, the recovered anchor fragment can be easily transported and discarded.

The side view of an excavation apparatus provided with the removal apparatus of one Embodiment of this invention. Sectional drawing which expanded the front-end | tip part of the removal apparatus of FIG. Sectional drawing which expanded the base end part of the removal apparatus of FIG. Sectional drawing of the modification of the base end part of the removal apparatus shown in FIG. The disassembled perspective view of the cutting | disconnection arm provided in the inner pipe | tube of FIG. Sectional drawing which crosses the rotation center line of the removal apparatus along F6-F6 line in FIG. Sectional drawing of the state by which the cutting arm of the removal apparatus of FIG. Sectional drawing of the covering process which excavates the circumference | surroundings of an anchor with the excavation apparatus of FIG. FIG. 9 is a cross-sectional view of a state where the anchor is dug to a predetermined depth following FIG. 8. Sectional drawing of the cutting process which cut | disconnects the anchor dug to the predetermined depth in FIG. Sectional drawing of the collection | recovery process which takes out one part of the anchor cut | disconnected in FIG. Sectional drawing of the restoration process which inserted the inner pipe | tube into the outer pipe | tube after the collection | recovery process of FIG. Sectional drawing which performs a covering digging process again after the recovery process of FIG. Sectional drawing of the cutting process which cuts an anchor after the covering digging process of FIG. FIG. 15 is a cross-sectional view of a recovery process for extracting a part of the anchor after the cutting process of FIG. 14. The figure which shows the state which repeated the operation | work of FIGS. 12-15 after the collection process of FIG. 15, and removed the anchor from the ground.

  A removal apparatus 10 according to an embodiment of the present invention and an anchor A removal method using the same will be described with reference to FIGS. 1 to 16. 1 to 7 show the structure of the removal device 10. 8 to 16 show the removal method for removing the anchor A from the ground using the removal device 10 in stages. In the explanation using each figure, for convenience of explanation, “upper” and “lower” are respectively defined on the basis of the direction in which gravity acts, and the clockwise direction when the removal device 10 is viewed from the ground side is “rightward”. The counterclockwise direction is defined as “counterclockwise”.

  The removal device 10 shown in FIG. 1 is attached to the head 2 of the excavator 1. The excavator 1 has an arm 3 that can freely adjust the head 2 to an angle at which an existing anchor A is embedded. The excavator 1 holds the central axis T of the removal device 10 mounted on the head 2 coaxially with the central axis C of the anchor A. The head 2 includes a guide rail 21 and a driving device 22 having a stroke for feeding or pulling out the removing device 10.

  The removal device 10 includes an inner tube 11, an outer tube 12, a cutting arm 13, a convex portion 14, a swivel 15, and a lock mechanism 16. As shown in FIGS. 2 and 8, the inner tube 11 has a digging blade 111 at the tip, and rotates counterclockwise around the existing anchor A to dig the outer periphery thereof. The outer tube 12 has a digging blade 121 similar to that of the inner tube 11 at the tip, is arranged with a gap G outside the inner tube 11, and rotates counterclockwise together with the inner tube 11. Drill the outer periphery.

  As shown in FIGS. 2, 5, and 6, the cutting arm 13 has a proximal end portion 131 pivotally mounted in the vicinity of the distal end portion of the inner tube 11, and extends rearward in the rotation direction (counterclockwise) of the inner tube 11. The distal end portion 132 has a blade 133 for cutting the anchor A. As shown in FIGS. 5 and 6, the cutting arm 13 is housed in a slot 112 opened in the circumferential direction in the inner tube 11, and a support shaft 134 provided on the base end portion 131 is held by a holding metal fitting 113. ing. The holding metal fitting 113 may be welded to the inner tube 11 or may be fixed with a bolt so that the cutting arm 13 can be replaced. As shown in FIG. 6, the cutting arm 13 is formed so as to gradually protrude from the outer peripheral surface of the inner tube 11 from the distal end portion 132 to the proximal end portion 131 in a state where the distal end portion 132 is accommodated in the slot 112. .

  As shown in FIG. 6, the convex portion 14 is provided on the inner peripheral surface of the outer tube 12 at a position corresponding to the cutting arm 13. As shown in FIG. 7, the convex portion 14 pushes the cutting arm 13 toward the central axis C of the anchor A when the outer tube 12 rotates in the rotation direction (counterclockwise) with respect to the inner tube 11. .

  As shown in FIG. 6, a plurality of cutting arms 13 are provided in the circumferential direction of the inner tube 11, and two cutting arms 13 are provided in the present embodiment. Three cutting arms 13 may be provided at equal intervals in the circumferential direction. The same number of protrusions 14 as the cutting arms 13 are provided. The distal end 132 of the cutting arm 13 rotates toward the central axis T of the removal device 10 as shown in FIG. Therefore, the length of the cutting arm 13 is substantially equal to the radius of the inner tube 11 so as to contact the outer peripheral surface of the anchor A in a tangential direction while cutting the anchor A. The blade 133 attached to the distal end portion 132 of the cutting arm 13 is arranged in a direction intersecting the outer peripheral surface of the anchor A, and the removal device 10 rotates around the anchor A so as to be pulled in the rotation direction. The anchor A can be cut and cut.

  As shown in FIG. 3, the swivel 15 has an inner spindle 151, an outer spindle 152, and a housing 153. The inner spindle 151 is connected to the proximal end 115 of the inner tube 11, and the outer spindle 152 is connected to the proximal end 125 of the outer tube 12. The outer spindle 152 covers the outer periphery of the inner spindle 151, engages with the inner spindle 151 in a direction along the central axis T of the removal device 10, and is rotatable relative to the central axis T. When the existing anchor A is dug in order to extract it from the ground, the inner pipe and the outer pipe are arranged between the base ends 115 and 125 and the inner spindle 151 and the outer spindle 152 depending on the length of the anchor A. The extension pipe is added to the.

  The housing 153 is provided so as to move along the guide rail 21 of the head 2 of the excavator 1, and is moved by the feeding device 221 of the drive device 22. The outer spindle 152 is connected to the rotation motor 222 of the driving device 22 and is driven to rotate.

  The lock mechanism 16 is provided in the swivel 15 and has a function of switching to a connected state P1 in which the inner spindle 151 is coupled to the outer spindle 152 or a release state P2 in which the inner spindle 151 can be rotated with respect to the outer spindle 152. Have. In other words, it is only necessary to have a mechanism in which the connection state P1 is set when excavating the outer periphery of the anchor A and the release state P2 is set when the anchor A is cut using the cutting arm 13.

  Specifically, in the case of this embodiment, the lock mechanism 16 is fitted to the inner spindle 151 from the outer peripheral side of the outer spindle 152 through the through hole 152A provided in the outer spindle 152, as shown in FIG. The lock pin 161 is inserted in the hole 151A in the radial direction. The lock pin 161 is inserted into the through hole 152A and the fitting hole 151A to be in the connected state P1, and the lock pin 161 is pulled out from at least the fitting hole 151A to be in the released state P2. The lock pin 161 may penetrate in the diameter direction, or a plurality of lock pins 161 may be provided.

  As another embodiment of the lock mechanism 16, a modification is shown in FIG. 4 is arranged between a first coupling portion 162 formed at the end of the inner spindle 151 opposite to the side to which the inner tube 11 is connected, and between the inner spindle 151 and the outer spindle 152. And a fitting block 163. The fitting block 163 includes a second coupling portion 163A that fits the first coupling portion 162 of the inner spindle 151, and a coupling bar 163B that extends from the coupling block 163 through the outer spindle 152 in the radial direction. The through hole 152A of the outer spindle 152 through which the coupling bar 163B is passed is formed as a long hole in the direction along the central axis T of the removal device 10. When the coupling bar 163B is operated toward the inner spindle 151, as shown by a two-dot chain line in FIG. 4, the second coupling portion 163A of the fitting block 163 is fitted and connected to the first coupling portion 162. When P1 is reached and the coupling bar 163B is operated in a direction away from the inner spindle 151, a release state P2 is obtained as shown by a solid line in FIG.

  Note that the lock pin 161 shown in FIG. 3 and the coupling bar 163B shown in FIG. 4 may be operated manually or by another drive mechanism. Further, the lock mechanism 16 may have a structure other than that shown in FIGS. 3 and 4. For example, the lock mechanism 16 has a spline groove formed on the outer peripheral surface of the end portion of the inner spindle 151 opposite to the side to which the inner tube 11 is connected, and a convex formed on the outer spindle 152 so as to mesh with the spline groove. The connection state P1 or the release state P2 may be achieved by fitting or removing the spline groove and the convex portion along the central axis T. Further, the lock mechanism 16 may include a clutch mechanism that can finely adjust the difference in rotation angle between the outer spindle 152 and the inner spindle 151. Alternatively, the lock mechanism 16 includes a transmission and a cam mechanism in which the rotation of the inner spindle 151 is gradually delayed with respect to the outer spindle 152 by rotating the inner spindle 151 and the outer spindle 152 after the release state P2. Also good.

  Further, as shown in FIG. 3, the swivel 15 has a configuration capable of supplying the circulating water W for excavation to the inside of the inner tube 11 and the gap G between the inner tube 11 and the outer tube 12. In the case of this embodiment, the swivel 15 has a gap between the water supply path 154 that supplies the circulating water W to the inside of the inner pipe 11 through the housing 153, the outer spindle 152, and the inner spindle 151, and the outer spindle 152 and the housing 153. And a drainage path 155 for discharging the circulating water W of G to the outside of the swivel 15. The water supply path 154 and the drainage path 155 are in the connected state P1 or the released state P2 regardless of the position of the rotation angle of the outer spindle 152 relative to the housing 153 and the rotation angle of the inner spindle 151 relative to the outer spindle 152. In either case, they are provided to communicate individually. Specifically, as shown in FIG. 3, grooves 154 </ b> A and 154 </ b> B are formed on the inner peripheral surface of the housing 153 of the water supply passage 154 and the inner peripheral surface of the outer spindle 152. A groove 155A is formed on the inner peripheral surface of the housing 153 over the entire circumference. O-rings and gaskets are mounted as seal materials on both sides of each of the grooves 154A, 154B, 155A along the central axis T of the removal device 10.

  Furthermore, in order to make it easy to align the position of the cutting arm 13 and the convex portion 14 in the direction along the central axis T, the removal device 10 has an outer tube 12 on the tip side of the convex portion 14 as shown in FIG. A support ring 17 is provided on the inner peripheral surface, and a guide 18 that abuts the support ring 17 from the base end 115 side on the support ring 17 at a position where the cutting arm 13 faces the convex portion 14 is provided on the outer peripheral surface of the inner tube 11. ing. When connecting the extension pipes to the inner pipe 11 and the outer pipe 12, respectively, the cutting arm 13 and the convex portion 14 can be easily positioned.

  The guide 18 provided in the inner tube 11 needs to go over the convex portion 14 provided in the outer tube 12. Considering the positioning of the rotation angle of the cutting arm 13 with respect to the convex portion 14, the guide 18 may be provided at the same position in the rotation direction as the base end portion 131 of the cutting arm 13. In order to align the positions of the cutting arm 13 and the convex portion 14 in the direction along the central axis T of the removal device 10, a support ring 17 may be provided on the outer peripheral surface of the inner tube 11. In that case, the support ring 17 is provided so as to come into contact with the convex portion 14 from the base end 115 side. The convex portion 14 functions as a guide 18 provided on the outer tube 12.

  The removal method of the existing anchor A embed | buried in order to reinforce the slope N using the removal apparatus 10 comprised as mentioned above is demonstrated with reference to FIGS. FIG. 8 shows a so-called “covering process” in which the removal device 10 held by the head 2 of the excavating device 1 is placed on the ground-side end of the anchor A and excavated around the anchor A from the surface of the slope N. FIG. In FIG. 8, the periphery of the anchor A is dug while rotating counterclockwise (counterclockwise) in which the swivel 15 is connected to the connected state P1 by the lock mechanism 16 and the inner tube 11 and the outer tube 12 are integrated. Circulating water W for excavation is supplied to the inside of the inner pipe 11 via the swivel 15 and flows into the gap G between the inner pipe 11 and the outer pipe 12 around the tip of the excavating blade 111 at the tip of the inner pipe 11. . Circulating water W that has come out from the tip of the inner tube 11 may further flow around the tip of the outer tube 12 and flow out to the outside of the outer tube 12. The mud soil dug by the excavation blade 111 at the tip of the inner tube 11 and the excavation blade 121 at the tip of the outer tube 12 is collected through the gap G between the inner tube 11 and the outer tube 12.

  The covering digging step S1 is carried out by the feeding device 221 that feeds the ground tube while rotating the outer tube 12 and the inner tube 11 with the rotary motor 222 of the drive device 22 of the head 2 of the excavator 1. As shown in FIG. 9, when digging along the anchor A and excavating from the surface of the slope N to a certain depth, the lock mechanism 16 is set in the released state P2, and the outer spindle is moved to that depth as shown in FIG. Cutting process S2 which rotates 152 is implemented. When the outer tube 12 is rotated, the convex portion 14 pushes the cutting arm 13 of the inner tube 11 toward the center, the convex portion 14 engages with the cutting arm 13, and the inner tube 11 rotates with the outer tube 12. .

  The rotational resistance at which the convex portion 14 engages the cutting arm 13 in the rotational direction is greater than the rotational resistance when cutting the anchor A in the tangential direction by the blade 133 attached to the distal end portion 132 of the cutting arm 13. The contact part of the cutting arm 13 and the convex part 14, the rake angle of the blade 133, etc. are each formed so that it may become large. The blades 133 may be provided in multiple stages instead of one for each cutting arm 13.

  As the inner tube 11 rotates along with the outer tube 12, the blade 133 attached to the distal end portion 132 of the cutting arm 13 scrapes the outer peripheral surface of the anchor A, so that the anchor A gradually becomes thinner. Finally, it is cut as shown in FIG. The fact that the anchor A has been cut can be easily determined by detecting the torque change of the rotary motor 222.

  When the anchor A is cut, a recovery step S3 for discharging the cut fragment A1 of the anchor A to the ground is performed as shown in FIG. In the collecting step S3, the outer spindle 152 is removed from the outer tube 12, and the swivel 15 and the inner tube 11 are pulled up as shown in FIG. At this time, the fragment A1 of the anchor A is in a state where the distal end portion 132 is supported by the cutting arm 13 rotated to the central axis T. As shown in FIG. 12, after discharging the fragment A1 of the anchor A from the inner tube, the restoration step S4 for inserting the inner tube 11 into the outer tube 12 again is performed. In the recovery step S <b> 4, the inner tube 11 is inserted into the outer tube 12 until the guide 18 contacts the support ring 17, and the outer spindle 152 is connected to the base end 125 of the outer tube 12. After the rotation angles of the cutting arm 13 and the convex portion 14 are positioned as shown in FIG. 6, the swivel 15 is brought into the connected state P1 by the lock mechanism 16.

  Then, the periphery of the anchor A is excavated to a desired depth in the covering step S5 shown in FIG. 13, and the anchor A corresponding to the depth dug in the cutting step S6 shown in FIG. 14 is cut. The fragment A1 of the cut anchor A is discharged to the ground in the recovery step S7 shown in FIG. 15, and returns to the recovery step S4 shown in FIG. The recovery process S4 shown in FIG. 12 to the recovery process S7 shown in FIG. 15 are repeated for the number of times corresponding to the length of the anchor A, and the operation of recovering the fragment A1 is repeated. As shown in FIG. Remove. In general, the length of the anchor A is sufficiently longer than the stroke of the guide rail 21 of the head 2 of the excavator 1, so that an extension pipe is added to the inner pipe 11 and the outer pipe 12 as the anchor A is dug. The extension pipe of the added inner pipe 11 is once separated when the fragment A1 is recovered, and then the extension pipe is added by a required length in the recovery step S4.

  Thus, according to the removal method of this embodiment, no matter how long the anchor A is, the recovery step S4 shown in FIG. 12 to the recovery step S7 shown in FIG. As shown, the anchor A can be completely removed. Moreover, since it can collect | recover as the fragment | piece A1 cut | disconnected by the desired length, it is easy to convey and exhaust the fragment | piece A1 collect | recovered on the ground.

  Moreover, according to the removal apparatus 10 of this invention, in order to cut | disconnect the anchor A at the front-end | tip part of the removal apparatus 10, a complicated drive mechanism and supply of motive power are not required. Therefore, since the structure is simple, there is less concern about breakdowns, and the costs associated with delicate construction management and maintenance of the apparatus are reduced. Moreover, even if the existing anchor A that is buried becomes long, if the depth is such that excavation is possible by adding the inner pipe 11 and the outer pipe 12 of the removal device 10 with an extension pipe, the anchor A is completely extended to the tip. Can be removed. And since the existing anchor A can be completely removed, even if renovation work considering expiration of the service life or deterioration over time is necessary, a new hole is removed by using the hole from which the existing anchor A has been removed. An anchor can be installed.

  In the above-described embodiment, an example in which the removal device 10 is applied to removing the existing anchor A installed on the slope N has been shown. This removal device 10 is not only for anchor A installed on slope N, but also for anchors of buildings such as buildings, bridges, steel towers, etc. built on flat ground, revetment reinforcement, ceiling inner wall including ceiling It is also effective for the removal work of anchors installed for reinforcement.

  DESCRIPTION OF SYMBOLS 10 ... Removal apparatus 11 ... Inner pipe | tube, 115 ... Base end, 12 ... Outer pipe | tube, 125 ... Base end, 13 ... Cutting arm, 131 ... Base end part, 132 ... Tip part, 133 ... Blade, 14 ... Convex part, DESCRIPTION OF SYMBOLS 15 ... Swivel, 151 ... Inner spindle, 152 ... Outer spindle, 16 ... Lock mechanism, 17 ... Supporting ring, 18 ... Guide, P1 ... Connection state, P2 ... Release state, S1, S5 ... Covering process, S2, S6 ... Cutting step, S3, S7 ... Recovery step, S4 ... Recovery step, A ... Anchor, C ... Center axis of anchor, G ... Gap, T ... Center axis of removal device, W ... Circulating water

Claims (7)

An inner pipe that rotates around an existing anchor and excavates the outer circumference;
An outer tube that is mounted on the outside of the inner tube with a gap and rotates to excavate the outer periphery of the inner tube;
A cutting arm having a blade for cutting the anchor at a distal end portion pivotally attached to the vicinity of the distal end portion of the inner tube and extending rearward in the rotation direction of the inner tube;
A convex portion that is provided on the outer tube at a position corresponding to the cutting arm and pushes the cutting arm toward the center of the anchor by rotating the outer tube in advance of the rotation direction with respect to the inner tube; ,
A swivel having an inner spindle connected to the proximal end of the inner tube and an outer spindle that covers the outside of the inner spindle and is connected to the proximal end of the outer tube;
A locking mechanism that is provided on the swivel and switches to a connected state in which the inner spindle is coupled to the outer spindle or a released state that allows the inner spindle to rotate with respect to the outer spindle;
A removal device comprising: The removal device according to claim 1, wherein a plurality of the cutting arms are provided at equal intervals in a circumferential direction of the inner pipe. The angle at which the cutting arm protrudes toward the center of the inner tube changes according to an angle at which the outer tube precedes the inner tube in a rotational direction. Removal device. The tip of the cutting arm abuts the outer peripheral surface of the anchor in a tangential direction while cutting the anchor,
The said blade is arrange | positioned in the direction which cross | intersects with respect to the outer peripheral surface of the said anchor, The said anchor is cut | disconnected so that it may cut in the rotation direction, The removal apparatus described in Claim 1 characterized by the above-mentioned. The outer tube has a support ring on the inner peripheral surface on the tip side from the convex portion,
2. The removal device according to claim 1, wherein the inner tube has a guide that comes into contact with the support ring from the base end side at a position where the cutting arm faces the convex portion. The removal device according to claim 1, wherein the swivel supplies circulating water for excavation to the inside of the inner pipe and the gap. A removal method for removing the existing anchor from the ground using the removal device according to any one of claims 1 to 6,
Covering the ground-side end of the anchor with the removal device in which the swivel is connected by the lock mechanism, and rotating the swivel to dig around the anchor; and
After the swivel is released by the locking mechanism, the outer spindle is rotated at a certain depth, and the cutting arm is pushed out toward the center of the inner tube by the convex portion while rotating the inner tube, A cutting step of cutting the anchor;
A recovery step of removing the outer spindle from the outer tube and lifting the swivel and the inner tube to discharge the cut fragments of the anchor to the ground while being supported by the cutting arm;
A recovery step of inserting the inner tube into the outer tube, connecting the outer spindle to the base end of the outer tube, and bringing the swivel into a connected state by the lock mechanism, and repeating these steps a plurality of times in order Removal method to remove the existing anchor.

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