JP2010077600A - Cutting device and removal method for existing pile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cutting device capable of simply cutting an existing pile while avoiding the biting and rupture of a wire saw, and to provide a removal method for simply cutting and removing the existing pile while avoiding the biting and rupture of the wire saw. <P>SOLUTION: An outside casing 2 and an inside casing 1 which have inside diameters larger than the outside diameter of the existing pile 10, are pressed into the ground in this order almost coaxially with the existing pile 10, and then, sediment between the inside casing 1 and outside casing 2 is at least partially removed. The existing pile 10 is cut with the wire saw 9, which is put over a drive unit, a main guide pulley and a direction changing pulley and which is guided into the inside casing 1 from a window for cutting, and cut pieces are removed. By the cutting device and the removal method for the existing pile, the cut pieces are supported by the sediment 12 in the inside casing, so as to avoid a load imposed on the wire saw 9 due to gravity applied to the cut pieces. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a cutting device for an existing pile buried in the ground, and a removal method for cutting and removing the existing pile.

  Pile is driven into the ground as the foundation of the building or for ground improvement, but when dismantling the existing building and building a new building, or performing new ground improvement construction, It gets in the way and needs to be removed. As a method of removing existing piles that are no longer needed, a method of destroying existing piles from the top is widely used, but it takes tremendous labor, time and cost to dispose of huge pieces of debris generated at the site. In other words, there has been a problem of generating large noises and vibrations over a long period of time. Moreover, although the construction method which pulls out a pile is also known, it was not applicable to a long or large diameter pile, and there was a problem with poor generality. Therefore, the construction method which cuts and removes an existing pile sequentially from an upper end, or the apparatus for the construction method is indicated.

  For example, a steel pipe casing having a diameter larger than that of the foundation pile is press-fitted around the existing foundation pile, and the space between the casing and the foundation pile is scraped to form a space. Inserting a wire saw device having a wire saw, driving the wire saw device, cutting the foundation pile to a desired length and then sequentially removing it, and cutting and removing the existing foundation pile, An existing foundation pile cutting and removing device used in the construction method is disclosed (for example, see Patent Document 1).

  Further, it is an existing pile removal method for cutting and removing an existing pile buried in the ground, and a casing having an inner diameter larger than the outer diameter of the existing pile is substantially coaxial with the existing pile, and a predetermined A first step of press-fitting to an underground depth; a second step of removing earth and sand between the existing pile and the casing to provide a space around the existing pile; and a wire provided outside the space A third step of arranging wire saw guide means for guiding the wire saw driven by a saw drive device movably and cutting the existing pile in a horizontal direction at a predetermined depth in the space; and the wire A fourth step of horizontally cutting the existing pile at the predetermined depth position by a saw; and a fifth step of lifting the cut existing pile upward and carrying it out of the casing. The first The fifth step sequentially performed, existing pile removal method to remove only the necessary length of the existing pile, and cutting device of the columnar structures used in 該工 method is disclosed (e.g., see Patent Document 2).

JP 2001-262570 A JP 2003-155746 A

  However, all of the construction methods described in the above-mentioned patent documents are methods of cutting the existing pile after scraping the earth and sand that are in direct contact with the existing pile, and are applied to the wire saw due to the gravity applied to the cutting piece above the wire saw. There is a risk that the load is applied, the wire saw is bitten and cannot be moved, and the wire saw is broken.

  To prevent biting of the wire saw, it is disclosed that after cutting a plurality of places at the same depth and then breaking a part near the shaft that is not cut, the wire saw is removed from the existing pile in the middle of cutting. This is difficult in practice and increases the risk of breaking the wire saw. In order to avoid this, it is possible to continue lifting the cutting piece above the wire saw or to drive a wedge into the cutting portion, but in order to apply these methods, a large-scale device or a special device is required. In addition, since the procedure is complicated, a great deal of labor is required.

  In view of these problems, an object of the present invention is to provide a cutting device that can easily cut an existing pile while avoiding biting and breaking of the wire saw by reducing the load applied to the wire saw. To do. It is another object of the present invention to provide a removal method for easily cutting and removing an existing pile while avoiding biting and breaking of a wire saw.

The present invention for solving the above problems
[1] A cutting device for cutting existing piles buried in the ground,
Tubular inner casing having an inner diameter larger than the outer diameter of the existing pile, Tubular outer casing having an inner diameter larger than the outer diameter of the inner casing and arranged substantially coaxially with the inner casing, outward of the outer peripheral surface of the inner casing 2 main guide pulleys that are arranged in the vertical direction, a cutting window drilled in the peripheral wall of the inner casing, and a rotating shaft that is disposed outward of the outer peripheral surface of the inner casing. Two direction-changing pulleys that are freely pivoted and provided at approximately the same height as the cutting window, and that are erected at approximately the same height as the cutting window on the inner peripheral surface of the inner casing A wire guide spanned from the stopper, the drive unit to the main guide pulley, and then to the direction change pulley and led from the cutting window into the inner casing, and the main guide pulley attached to the outer peripheral surface of the inner casing , Redirecting pulleys, and a protective cover covering the cutting window comprising,
It is the existing pile cutting device characterized in that a portion in the inner casing of the wire saw can be locked to the locking portion.

[2] The existing pile cutting apparatus according to [1], wherein the engaging portion is made of an elastic material.

[3] The existing pile cutting apparatus according to [1] or [2], wherein a water guide pipe communicating with the inside of the protective cover is provided.

[4] The radius of the main guide pulley and direction change pulley is 5 to 8 times the maximum cross-sectional diameter of the wire saw, and the groove depth is 1.5 to 3.0 times the maximum cross-sectional diameter of the wire saw. And the opening width of the groove | channel on the outer periphery is 1.5 times or more and 3.0 times or less of the largest cross-sectional diameter of a wire saw, The cutting of the existing pile in any one of said [1] thru | or [3] characterized by the above-mentioned. Device.

Also,
[5] A method for removing existing piles buried in the ground,
(A) A step of pressing a tubular outer casing having an inner diameter larger than the outer diameter of the existing pile into the ground substantially coaxially with the existing pile (B) An inner diameter larger than the outer diameter of the existing pile and an inner diameter of the outer casing Two main guide pulleys that have a small outer diameter and are arranged outside the outer peripheral surface and are rotatable in the vertical direction, a cutting window drilled in the peripheral wall, and a rotary shaft arranged outside the outer peripheral surface Two direction-changing pulleys, which are pivotally supported in a horizontal direction and provided at substantially the same height as the cutting window, and are erected at substantially the same height as the cutting window on the inner peripheral surface. A locking saw, a main guide pulley from the driving device, and then a wire saw that is stretched over the direction change pulley and led from the cutting window into the inner casing, and a main guide pulley that is attached to the outer peripheral surface, a direction change pulley, And a protective cover covering the cutting window (C) Step of removing at least a part of earth and sand between inner casing and outer casing (D) Locking of wire saw (E) The process (A) thru | or (F) performed in order of the process which lifts and removes the cut piece of the existing pile cut | disconnected by the process (E) process (E) which cuts an existing pile with a wire saw This is a method of removing existing piles including

[6] The existing pile according to [5], wherein the engaging portion is made of an elastic material, and the step (D) is performed by starting driving of the wire saw or applying tension to the wire saw. It is a removal method.

[7] The method for removing an existing pile according to the above [5] or [6], wherein the step (E) is performed while guiding a water flow through a water conduit inside the protective cover.

[8] The radius of the main guide pulley and the direction change pulley is 5 to 8 times the maximum cross-sectional diameter of the wire saw, and the groove depth is 1.5 to 3.0 times the maximum cross-sectional diameter of the wire saw. And it is the removal method of the existing pile in any one of said [5] thru | or [7] whose opening width of the groove | channel in an outer periphery is 1.5 to 3.0 times the largest cross-sectional diameter of a wire saw.

  According to the existing pile cutting apparatus or the existing pile removing method according to the present invention, the existing pile can be cut while holding the earth and sand in the inner casing, so that the cut piece is supported by the earth and sand during the cutting. Maintained. In addition, it is expected that surrounding earth and sand enter a gap generated by cutting with a wire saw, and that the earth and sand support the cut piece. For these reasons, it is avoided that a load is applied to the wire saw due to the gravity applied to the cut piece, and it is possible to prevent the wire saw from being bitten and broken.

  Since cutting is performed with the existing pile supported by the earth and sand, cutting is completed by a single cutting operation without supporting the existing pile by special operations such as lifting the cutting piece or driving a wedge into the cutting part. it can. Since it is not necessary to cut a plurality of places except for a part near the axis of the existing pile, it is possible to avoid breakage of the wire saw due to removal from the cut place.

  As described above, since the wire saw can be prevented from being bitten and broken, the frequency of replacing the wire saw can be reduced and the cost can be suppressed.

  In addition, since the inner casing can be press-fitted into the ground with the wire saw locked to the locking portion provided along the inner circumference of the inner casing, the wire saw can be cut to a desired depth only by press-fitting the inner casing. And can start cutting existing piles.

  Since the main guide pulley and the direction change pulley are covered with the protective cover, the load applied when the inner casing is press-fitted into the ground or the existing pile is cut with a wire saw can be reduced, and damage to the pulley can be prevented.

  Since the inflow of earth and sand from the outside of the outer casing can be prevented, it is possible to easily perform the work of cutting the existing pile at a number of locations by repeatedly press-fitting the inner casing, cutting the existing pile, and pulling out the inner casing. Thereby, the weight of the cut piece generated by one cutting operation is suppressed, and the cut piece can be easily taken out from the construction site and disposed of by means such as crushing at a place different from the construction site. Since it is not necessary to dispose of the cut piece near the construction site, the cutting work of the existing pile can be completed in a short period of time.

  In addition, after cutting and removing all existing piles and pulling out all members other than the outer casing, the ground hole at the construction site is prevented from becoming liquefied by pulling out the outer casing and backfilling the excavation holes generated in the construction. Can do.

  According to the invention described in [2] or [6] above, since the locking portion is made of a material having elasticity, the wire saw starts to be driven or tension is applied to the wire saw via the main guide pulley. Unlocking just by adding can start cutting existing piles without adding any special operations. Moreover, since the latching | locking part is produced with the material which has elasticity, the latching | locking part is not damaged by the operation which cancels | releases latching, and the said cutting device can be used repeatedly.

  According to the invention described in [3] or [7] above, the water flow is discharged from the wire saw insertion hole provided in the cutting window or the protective cover by guiding the water flow into the protective cover through the water conduit. The The water stream plays a role of discharging the earth and sand that has entered the protective cover from the cutting window or the wire saw insertion hole, and preventing the earth and sand from entering the protective cover. Thereby, the rotational load by the earth and sand of a guide pulley and a direction change pulley is reduced, and the existing pile can be cut | disconnected more smoothly by a wire saw. As the water flow, it is preferable to use a high-pressure water flow, and thereby the above-described effect is more remarkable.

  According to the invention described in [4] or [8] above, since a pulley having a smaller diameter than that of a conventional wire saw pulley is used, the size of the protective cover can be reduced, and the inner casing can be grounded. It is possible to reduce the load applied to the protective cover, the main guide pulley, and the direction changing pulley when press-fitting into the cover, thereby avoiding wear of the member. Further, since the pulley has a small diameter, even if earth and sand enter the protective cover, the rotational load caused by the earth and sand is small, and the pulley can rotate stably and smoothly.

  Since the groove depth of the pulley is deeper than that of the conventional pulley, the wire saw is difficult to come off despite being a small-diameter pulley. Moreover, since the opening width of the groove | channel in the outer periphery of a pulley is made wider than before, even if a wire saw shakes in the axial direction of a pulley, it is hard to come off.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings, but the present invention is not limited thereto.

  First, the existing pile cutting apparatus according to the present invention will be described.

  FIG. 1 is a side view showing an existing pile removal method according to the present invention. FIG. 2 is a cross-sectional view of the main part showing the vicinity of the protective cover of the inner casing. FIG. 3 is a front view of a main part near the protective cover of the inner casing, with the protective cover cut open. FIG. 4 is an end view of a main part showing a cross section taken along line XX of FIG. FIG. 5 is a cross-sectional view showing a state before the cutting of the existing pile is started, and FIG. 6 is a cross-sectional view showing a state where the existing pile is being cut. In addition, the white arrow in a figure shows the drive direction (movement direction) of a wire saw.

  The cutting device for an existing pile according to the present invention is a cutting device for cutting an existing pile 10 buried in the ground, and is an inner tubular casing 1 having an inner diameter larger than the outer diameter of the existing pile 10. A tubular outer casing 2 having an inner diameter larger than the outer diameter of the casing 1 and arranged substantially coaxially with the inner casing 1 is provided.

  Two main guide pulleys 3 and 3 that are rotatable in the vertical direction are arranged outside the outer peripheral surface of the inner casing 1. A cutting window 5 is formed in the peripheral wall of the inner casing 1. Two direction change pulleys 4, 4 are provided on a rotary shaft arranged outside the outer peripheral surface of the inner casing 1 so as to be pivotable in the horizontal direction, and the direction change pulleys 4, 4 are provided. The height position is substantially the same as the height position of the cutting window 5. A protective cover 6 that covers the main guide pulleys 3, 3, direction change pulleys 4, 4, and the cutting window 5 is attached to the outer peripheral surface of the inner casing 1.

  On the inner peripheral surface of the inner casing 1, locking portions 8,... Are erected at substantially the same height as the cutting window 5.

  A wire saw 9 driven by a drive device (not shown) arranged on the ground is bridged from the drive device to the main guide pulleys 3, 3 and then to the direction change pulleys 4, 4, and from the cutting window 5 to the inside It is led into the casing 1. A portion of the wire saw 9 inside the inner casing 1 can be locked to the locking portions 8.

  The inner casing 1 is a tubular member having both ends opened. Although the material will not be specifically limited if it is a metal which has rigidity, It is preferable that steel materials are suitable and the surface is processed at least in the rust prevention process. The inner diameter of the inner casing 1 is made larger than the outer diameter of the existing pile 10 that is the object of cutting and removal.

  The outer casing 2 is a tubular member having both ends opened. Although the material will not be specifically limited if it is a metal which has rigidity, It is preferable that steel materials are suitable and the surface is processed at least in the rust prevention process. The inner diameter of the outer casing 2 is made larger than the outer diameter of the inner casing 1, and the outer casing 2 can be press-fitted into the ground substantially coaxially with the inner casing 1.

  Cutting blades 2 a are connected to the lower end of the outer casing 2. The cutting blades 2a,... Are provided in the same circumferential direction and can cut underground obstacles such as bedrock by rotating the outer casing 2, and even in places where the underground obstacles exist. It can be easily pressed into the ground. Further, by rotating the outer casing 2 provided with the cutting blades 2a,..., It is possible to press-fit the outer casing silently while suppressing the generation of noise. The shape, material, etc. of the cutting blades 2a,... Are not particularly limited, and if the outer casing 2 can be press-fitted, the cutting blades 2a,.

  The main guide pulleys 3 and 3 are provided at positions near the outer peripheral surface near the lower end of the inner casing 1. In the drawing, the rotation shaft is fixed to a pedestal 3a erected on the outer peripheral surface of the inner casing 1, and the main guide pulleys 3 and 3 are provided. However, the mounting method is not particularly limited. A wire saw 9 is stretched over the main guide pulleys 3 and 3, and a portion of the wire saw 9 between adjacent main guide pulleys 3 and 3 is suspended by a driving device such as a motor arranged on the ground, The wire saw 9 is driven in a predetermined direction by the driving device. On the other hand, the portion of the wire saw 9 extending in a direction away from the main guide pulleys 3 and 3 is further stretched over the direction change pulleys 4 and 4 and is used for cutting the existing pile 10. The material of the main guide pulleys 3 and 3 is not particularly limited, but at least the surface of the groove with which the wire saw 9 comes into contact is made of hard rubber, and the remainder is preferably made of a rust-proof metal having rigidity.

  Direction change pulleys 4 and 4 are pivotally fixed at substantially the same height as the lower ends of the main guide pulleys 3 and 3. The rotation shafts of the direction conversion pulleys 4 and 4 are disposed outside the outer peripheral surface of the inner casing 1 and at positions close to the outer peripheral surface of the inner casing 1. The direction change pulleys 4, 4 only need to have at least the rotating shaft disposed outside the outer peripheral surface of the inner casing 1, and even if part of the direction change pulleys 4, 4 is inserted into the cutting window 5. good. The material of the direction change pulleys 4 and 4 is not particularly limited, but at least the surface of the groove with which the wire saw 9 comes into contact is made of hard rubber, and the remainder is preferably made of a rust-proof metal having rigidity.

  The main guide pulleys 3 and 3 and the direction change pulleys 4 and 4 are smaller in diameter, deeper than the conventional pulleys for wire saws, and wide in opening width on the outer periphery of the groove. The protective cover 6 is reduced in size by reducing the diameter, and the load applied to the protective cover 6, the main guide pulleys 3, 3, and the direction changing pulleys 4, 4 can be reduced by press-fitting the inner casing 1 into the ground. It is possible to avoid wear of the member. Further, since the pulley has a reduced diameter, even if earth and sand enter the protective cover 6, the rotation load caused by the earth and sand is small, and the pulley can rotate stably and smoothly.

  Since the groove depths of the main guide pulleys 3 and 3 and the direction changing pulleys 4 and 4 are deeper than those of the conventional pulleys, the wire saw 9 is difficult to come off despite being a small-diameter pulley. In addition, since the opening width of the groove on the outer periphery of the pulley is wider than before, even if the wire saw 9 sways in the axial direction of the pulley, the wire saw 9 is difficult to come off and is located at the deepest groove in the center in the axial direction. It is made to return.

  Preferably, the radius of the main guide pulleys 3, 3 and the direction change pulleys 4, 4 is 5 to 8 times the maximum cross-sectional diameter of the wire saw 9, and the groove depth is 1.5 times the maximum cross-sectional diameter of the wire saw 9. The opening width of the groove on the outer periphery is 1.5 times to 3.0 times the maximum cross-sectional diameter of the wire saw 9. This is because if the radius of the pulley is less than 5 times the maximum cross-sectional diameter of the wire saw 9, it is difficult to drive the wire saw 9 at a high speed so that it does not come off the pulley, and the radius of the pulley is the maximum of the wire saw 9 This is because if the cross-sectional diameter exceeds eight times, the load when driving the wire saw 9 or press-fitting the inner casing 1 into the ground increases, and the pulley may be damaged. Further, when the groove depth of the pulley is less than 1.5 times the maximum cross-sectional diameter of the wire saw 9, the wire saw 9 is easily detached from the pulley, and the groove depth of the pulley is 3. If it exceeds 0 times, the wire saw 9 cannot be sufficiently bent and cannot be brought into contact with the deepest part of the groove of the pulley having the radius. Furthermore, if the opening width of the groove on the outer periphery of the pulley is less than 1.5 times the maximum cross-sectional diameter of the wire saw 9, the wire saw 9 is easily detached from the pulley, and if it exceeds 3.0 times, the pulley itself is thickened. This is because the size of the protective cover 6 is inevitably increased, and the load when the inner casing 1 is press-fitted into the ground increases.

  Further, the main guide pulleys 3 and 3 and the direction change pulleys 4 and 4 are preferably in contact with the rotating shaft and the bearing in the structure with almost no gap so that earth and sand do not enter and inhibit rotation.

  As the pulley according to the present invention, the main guide pulleys 3 and 3 and the direction changing pulleys 4 and 4 are essential, but the present invention does not prevent the provision of pulleys other than those described above. For example, in order to drive the wire saw 9 more smoothly, a pulley can be further provided between the direction changing pulleys 4 and 4 and the cutting window 5. Although the material of the said pulley is not specifically limited, It is preferable that the surface of the groove | channel which the wire saw 9 contacts is made from hard rubber, and the remainder is a metal which has the rust-proof processed rigidity. The pulley preferably has a smaller diameter than the conventional wire saw pulley, is deepened in the groove, and has a wide opening width on the outer periphery of the groove. The radius is 5 which is the maximum cross-sectional diameter of the wire saw 9. 2 times or more and 8 times or less, the groove depth is 1.5 times or more and 3.0 times or less of the maximum cross-sectional diameter of the wire saw 9, and the groove opening width on the outer periphery is 1.5 times or more of the maximum cross-sectional diameter of the wire saw 9 It is more preferable that it is 3.0 times or less. Furthermore, it is preferable that the rotating shaft and the bearing in the pulley are in contact with each other with almost no gap so that the pulley does not enter and prevent rotation.

  The cutting window 5 is a horizontally long through hole formed in the peripheral wall of the inner casing 1. The height position is substantially the same as the direction change pulleys 4 and 4, and the wire saw 9 can be guided into the inner casing 1 without contact. The shape of the cutting window 5 is not particularly limited as long as the wire saw 9 can be inserted. Moreover, it is not necessarily limited to the single cutting window 5 being provided, and for example, the cutting windows 5 and 5 may be formed one by one near the two direction change pulleys 4 and 4. .

  The protective cover 6 is attached to the outer peripheral surface of the inner casing 1 by abutting the outer periphery thereof and being fixed by a fixing material 6 c. The protective cover 6 covers the main guide pulleys 3, 3, the direction changing pulleys 4, 4, and the cutting window 5, and has a function of protecting them. The material of the protective cover 6 is not particularly limited, but is preferably made of a rust-proof metal having rigidity. The shape of the protective cover 6 is not particularly limited as long as it can cover the main guide pulleys 3, 3, the direction change pulleys 4, 4, and the cutting window 5. Further, the main guide pulleys 3, 3, the direction changing pulleys 4, 4, and the cutting window 5 are not necessarily all covered with the single protective cover 6. For example, two cutting windows 5, 5 are provided. In the case of being drilled, two protective covers 6 and 6 may be provided to cover each of the main guide pulley 3, the direction changing pulley 4, and the cutting window 5.

  The kind of the fastening material 6c is not particularly limited, and any fastening material such as a screw or a bolt can be used. Further, if the protective cover 6 is attached to the inner casing 1, the protective cover 6 is not necessarily limited to fastening, and for example, the protective cover 6 may be welded to the outer peripheral surface of the inner casing 1.

  Two wire saw insertion holes 6a, 6a are formed in the upper portion of the protective cover 6, and a wire saw 9 is inserted through the wire saw insertion holes 6a, 6a. In order to prevent damage to the inner casing 1 and the protective cover 6 due to the contact of the wire saw 9, and to enable smooth driving of the wire saw 9, insertion tubes 6b and 6b connected to the wire saw insertion holes 6a and 6a are provided. It is preferable that In this case, the material of the insertion tubes 6b and 6b is not particularly limited, but at least the inner peripheral surface is preferably made of hard rubber.

  The main guide pulleys 3, 3, the direction changing pulleys 4, 4, the cutting window 5, and the protective cover 6 are not necessarily limited to the vicinity of the lower end of the inner casing 1, and may be provided at any height position. In order to save labor by reducing the press-fitting depth of the casing 1, it is preferably provided near the lower end of the inner casing 1.

  A water conduit 7 is provided on the upper portion of the protective cover 6, and a water supply device (not shown) such as a high-pressure pump disposed on the ground and the inside of the protective cover 6 are communicated with each other by the water conduit 7. A high-pressure water stream is supplied from the water supply device, and the high-pressure water stream is guided into the protective cover 6 through the water conduit 7 and once accumulated in the protective cover 6, the cutting window 5 and It is discharged from the wire saw insertion holes 6a, 6a. Thus, the earth and sand that has entered the protective cover 6 is discharged from the cutting window 5 or the wire saw insertion holes 6a and 6a, and the earth and sand from the cutting window 5 or the wire saw insertion holes 6a and 6a into the protective cover 6 is discharged. Intrusion of the main guide pulleys 3 and 3 and direction change pulleys 4 and 4 due to earth and sand can be avoided more reliably.

  The material of the water conduit 7 is not particularly limited, but a metal having rigidity that has been subjected to a rust-proofing process is preferably used. The shape of the water guide pipe 7 is not particularly limited as long as it can withstand a high-pressure water flow. Moreover, if the intrusion of earth and sand into the protective cover 6 can be prevented or the earth and sand that has entered the protective cover 6 can be discharged, the present invention is not necessarily limited to using a high-pressure water flow. You can also. The number of water conduits 7 is not necessarily limited to one, and two or more water conduits 7 may be provided.

  The locking portions 8,... Are hard rubber members formed in a substantially L-shape, and as shown in FIG. 4, they are erected on the inner peripheral surface of the inner casing 1 with their tips facing downward. Has been. The engaging portions 8 are disposed at substantially the same height as the cutting window 5, and the inner casing 1 is disposed in a state where the wire saw 9 is disposed along the inner peripheral surface of the inner casing 1. It is possible to press fit into the ground. Since the locking portions 8,... Are made of hard rubber, the locking of the locking portions 8,... To the wire saw 9 can be easily released simply by starting the driving of the wire saw 9 or applying tension to the wire saw 9. The cutting of the existing pile 10 can be started immediately after the wire saw 9 is arranged at a desired depth. Since the locking portions 8 are made of hard rubber, they can be used repeatedly without being cut by the wire saw 9.

  Although the material of the latching | locking part 8 ... is not specifically limited, The hard rubber which cannot be easily cut | disconnected with the wire saw 9 but can be easily unlocked is used suitably. It is also possible to make the locking portions 8,... With a material having rigidity and move them mechanically so as to release the locking. The shape of the locking portions 8,... Is not necessarily limited to a substantially L shape as long as the inner casing 1 can be press-fitted into the ground while the wire saw 9 is locked, and may be any shape. Moreover, the number of the latching | locking parts 8 ... will not be specifically limited if the wire saw 9 can be arrange | positioned along the internal peripheral surface of the inner side casing 1. FIG.

  The wire saw 9 should just be applicable to the cutting of the existing pile, and does not specifically limit the material, a shape, a cross-sectional diameter, etc. Preferably, an endless loop-shaped wire saw is used.

  Next, the removal method of the existing pile which concerns on this invention is demonstrated along a procedure.

  FIG. 7 is a side view showing a state in which the inner casing is lifted for evacuation after cutting an existing pile, and FIG. 8 is a side view showing a step of removing the cut piece.

[Step (A)]
The outer casing 2 is press-fitted into the ground using a hydraulic cylinder or the like so as to be substantially coaxial with the existing pile 10 to be removed. The press-fit depth of the outer casing 2 is set so that the lower end of the outer casing 2 is slightly deeper than the lower end of the existing pile 10. When the cutting edge 2a,... Is provided at the lower end of the outer casing 2, it is possible to perform a quiet press-fitting by rotating the outer casing 2 while rotating, and where there are underground obstacles such as bedrock. However, it is possible to press-fit into the ground while cutting the underground obstacle.

[Step (B)]
In advance, the wire saw 9 is bridged over the main guide pulleys 3 and 3 and the direction change pulleys 4 and 4, and a part of the wire saw 9 is guided from the cutting window 5 into the inner casing 1 to be connected to the locking portions 8. Lock it. In this state, the inner casing 1 is press-fitted into the ground using a hydraulic cylinder or the like. The press-fit depth of the inner casing 1 is a depth at which the cutting window 5 is disposed at a desired cutting depth. At this point, the wire saw 9 is disposed on the inner periphery of the inner casing 1 while being locked to the locking portions 8, as shown in FIG.

[Step (C)]
At least a part of the earth and sand between the inner casing 1 and the outer casing 2 is removed. The removal method is not particularly limited, but for example, a method in which a jet water stream is applied in a mud form and pumped out is suitably used. It is preferable to remove all the earth and sand at the depth position of the cutting window 5, but the earth and sand at a deeper position may be removed together, or a part of the earth and sand at the depth position of the cutting window 5 may be removed. The earth and sand may be removed, and the earth and sand remaining at a deeper depth may be suspended in water to form a mud.

[Step (D)]
Unlock the wire saw 9 by the locking portions 8. When the locking portions 8 are made of an elastic material, it is sufficient to start driving the wire saw 9 or apply tension to the wire saw 9 for the next step (E).

[Step (E)]
The wire saw 9 is driven, and the existing pile 10 is cut by the wire saw 9. Since the space between the inner peripheral surface of the inner casing 1 and the existing pile 10 is filled with earth and sand, the wire saw 9 that has been unlocked in the step (D) is initially pressed without drooping. It continues to be disposed at the depth position of the cutting window, that is, the depth position substantially equal to the cutting window 5. By applying tension in this state, the wire saw 9 is brought into contact with the outer peripheral surface of the existing pile 10 at a depth position substantially equal to the cutting window 5, and the existing pile 10 is cut substantially horizontally at the depth position. .

  According to the method of the present invention, since the existing pile 10 is cut in a state where the space between the inner peripheral surface of the inner casing 1 and the existing pile 10 is filled with earth and sand, the cut piece 10a of the existing pile 10 is formed in the inner casing. It is maintained in a state of being supported by the earth and sand 12. Therefore, even if the cutting of the existing pile 10 is substantially completed as shown in FIG. 6, it is possible to avoid the load on the wire saw 9 due to the gravity applied to the cut piece 10a, and the wire saw thereby 9 can also be avoided. Furthermore, since the cut piece 10a is maintained in a state supported by the earth and sand 12 in the inner casing, cutting can be completed by one cutting operation, and there is no need to cut the same depth position multiple times. Therefore, biting and breaking of the wire saw 9 can be avoided more reliably.

  Preferably, when a tension sensor is attached to the wire saw 9 and excessive tension is applied due to contact with an underground obstacle, or when the tension is extremely reduced due to breakage due to wear of the wire saw 9 or the like, driving is performed. The operation of the equipment is automatically stopped. This allows safer work.

  Preferably, the water supply device, the water conduit 7 and the protective cover 6 are disposed, and the existing pile 10 is cut while guiding a high-pressure water flow from the water supply device through the water conduit 7 into the protective cover 6. I do. The high-pressure water flow is accumulated in the protective cover 6 and then discharged from the cutting window 5 and the wire saw insertion holes 6a and 6a. As a result, the intrusion of earth and sand into the protective cover 6 is avoided, and the earth and sand that has entered the protective cover 6 are discharged from the cutting window 5 and the wire saw insertion holes 6a and 6a. 3 and the direction change pulleys 4 and 4 can be rotated more stably and smoothly, and the wire saw 9 can be driven more smoothly. In addition, it is not limited during this process (E) to introduce | transduce a water flow as mentioned above, For example, you may continue and introduce water from the process (B) to the process (E).

[Step (F)]
The cut piece 10a of the existing pile 10 generated by cutting in the step (E) is lifted and removed using a crane or the like. In order to facilitate the removal of the cut piece 10a, it is preferable to remove the earth and sand 12 in the inner casing in advance by applying a jet water flow in a mud shape and pumping it out. Further, before or after the cutting piece 10 a is removed, the inner casing 1 is pulled up and retracted from the excavation hole 11. The evacuation may be performed before or after removal of the cut piece 10a. However, in order to perform a work safely without bringing a number of heavy machinery close to each other, as shown in FIG. 7, before the cut piece 10a is removed. Preferably, it is done.

  By the series of steps (A) to (F), the cutting of the existing pile 10 and the removal of the cut piece 10a at the predetermined depth position are completed. At this time, only the uncut portion of the existing pile 10 and the outer casing 2 are left, and the excavation hole 11 shown in FIG. 8 is generated. Thereafter, by repeating the steps (B) to (F), the existing pile 10 can be repeatedly cut and removed completely. Thereafter, the ground of the construction site can be prevented from being liquefied by pulling out the outer casing 2 while filling the excavation hole 11 back.

It is a side view which shows the removal construction method of the existing pile which concerns on this invention. It is a principal part cross-sectional view which shows the protective cover vicinity of an inner casing. It is a principal part front view of the protection cover vicinity of an inner side casing which shows and shows a protection cover open. It is a principal part end elevation which shows the XX sectional view of FIG. It is a cross-sectional view which shows the state before starting the cutting of the existing pile. It is a cross-sectional view which shows the state which has cut | disconnected the existing pile. It is a side view which shows the state which lifted the inner casing for evacuation after cutting the existing pile. It is a side view which shows the process of removing a cut piece.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inner casing 2 Outer casing 2a Cutting blade 3 Main guide pulley 3a Base 4 Direction change pulley 5 Cutting window 6 Protective cover 6a Wire saw insertion hole 6b Insertion pipe 6c Fastening material 7 Water guide pipe 8 Locking part 9 Wire saw 10 Existing Pile 10a Cutting piece 11 Drilling hole 12 Earth and sand in inner casing

Claims (8)

A cutting device for cutting an existing pile buried in the ground,
Tubular inner casing having an inner diameter larger than the outer diameter of the existing pile, Tubular outer casing having an inner diameter larger than the outer diameter of the inner casing and arranged substantially coaxially with the inner casing, outward of the outer peripheral surface of the inner casing 2 main guide pulleys that are arranged in the vertical direction, a cutting window drilled in the peripheral wall of the inner casing, and a rotating shaft that is disposed outward of the outer peripheral surface of the inner casing. Two direction-changing pulleys that are freely pivoted and provided at approximately the same height as the cutting window, and that are erected at approximately the same height as the cutting window on the inner peripheral surface of the inner casing A wire guide spanned from the stopper, the drive unit to the main guide pulley, and then to the direction change pulley and led from the cutting window into the inner casing, and the main guide pulley attached to the outer peripheral surface of the inner casing , Redirecting pulleys, and a protective cover covering the cutting window comprising,
A cutting device for an existing pile, wherein a portion in the inner casing of the wire saw can be locked to the locking portion.   2. The existing pile cutting apparatus according to claim 1, wherein the engaging portion is made of an elastic material.   The existing pile cutting apparatus according to claim 1, wherein a water conduit that communicates with the inside of the protective cover is provided.   The radius of the main guide pulley and direction change pulley is 5 to 8 times the maximum cross-sectional diameter of the wire saw, the groove depth is 1.5 to 3.0 times the maximum cross-sectional diameter of the wire saw, and The opening width of a groove is 1.5 times or more and 3.0 times or less of the maximum section diameter of a wire saw, The cutting device of the existing pile according to any one of claims 1 to 3 characterized by things. It is a method of removing existing piles buried in the ground,
(A) A step of pressing a tubular outer casing having an inner diameter larger than the outer diameter of the existing pile into the ground substantially coaxially with the existing pile (B) An inner diameter larger than the outer diameter of the existing pile and an inner diameter of the outer casing Two main guide pulleys that have a small outer diameter and are arranged outside the outer peripheral surface and are rotatable in the vertical direction, a cutting window drilled in the peripheral wall, and a rotary shaft arranged outside the outer peripheral surface Two direction-changing pulleys, which are pivotally supported in a horizontal direction and provided at substantially the same height as the cutting window, and are erected at substantially the same height as the cutting window on the inner peripheral surface. A locking saw, a main guide pulley from the driving device, and then a wire saw that is stretched over the direction change pulley and led from the cutting window into the inner casing, and a main guide pulley that is attached to the outer peripheral surface, a direction change pulley, And a protective cover covering the cutting window (C) Step of removing at least a part of earth and sand between inner casing and outer casing (D) Locking of wire saw (E) The process (A) thru | or (F) performed in order of the process which lifts and removes the cut piece of the existing pile cut | disconnected by the process (E) process (E) which cuts an existing pile with a wire saw An existing pile removal method characterized by including   The existing pile according to claim 5, wherein the engaging part is made of an elastic material, and the step (D) is performed by starting driving of the wire saw or applying tension to the wire saw. Removal method.   The method for removing an existing pile according to claim 5 or 6, wherein the step (E) is performed while guiding a water flow through a water conduit inside the protective cover.   The radius of the main guide pulley and direction change pulley is 5 to 8 times the maximum cross-sectional diameter of the wire saw, the groove depth is 1.5 to 3.0 times the maximum cross-sectional diameter of the wire saw, and The method for removing an existing pile according to any one of claims 5 to 7, wherein the opening width of the groove is 1.5 to 3.0 times the maximum cross-sectional diameter of the wire saw.

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