JP2022032896A - Existing pile cutting-off removal device - Google Patents

Abstract

To provide an existing pile cutting-off removal device allowing a series of operations from excavation operation around the existing pile to pile cutting-off and removal operation to be efficiently performed.SOLUTION: An existing pile 4 cutting-off removal device provided with a drilling blade 14 and a cutting-off mechanism 30 on a lower end of a casing and provided with a driving mechanism on an upper end of the casing, wherein the cutting-off mechanism 30 is configured to be provided with: a swing body 44 placed inside of the casing, the swing body 44 formed in a generally semicircular shape, of which both ends in a circumferential direction are pivotably supported with a pivotal shaft 43 positioned coaxially in a chord direction of the casing so as to be swingably driven in a direction away from the shaft center of the casing; a first bit 51 detachably attached on an edge of the swing body 44; and a second bit 52 attached on an inner surface of the swing body 44. According to this configuration, the existing pile 4 is securely cut-off with the cutting-off mechanism 30 to allow existing pile cutting-off removal to be efficiently achieved in low construction cost.SELECTED DRAWING: Figure 4

Description

The present invention relates to an existing pile cutting / removing device that cuts and removes an existing pile buried in the soil from the upper side thereof.

As a method for removing existing piles buried in the soil, there are known a pull-out removal method in which the existing piles are integrally pulled out and removed, and a cutting and removal method in which the existing piles are cut and removed by a predetermined length from the upper end side thereof. Has been done. In particular, the latter is an effective method when it is not necessary to remove all the existing piles, only the part up to the predetermined depth on the ground surface side is removed, and it is sufficient to leave the part below it as it is, in terms of construction cost. In recent years, it has tended to be widely used due to the advantage of the above, and Patent Document 1 and Patent Document 2 show the construction method.

What is shown in Patent Document 1 is an underground obstacle removing device, which is arranged inside a tubular casing 100 that is built while rotating around an axis so as to surround the underground obstacle, and is a tubular casing. The grab holding portion 5 is formed in a semicircular shape having a pivot shaft 18 at both ends and a cutting blade 21 at the lower edge, and a grab holding portion 5 for digging and fitting between the inner circumference and the outer periphery of the underground obstacle. A pair of grab shells 7 rotatably arranged around the pivot shaft 18 at the bottom of 5, and a cutting blade rotating means provided above the grab shell 7 to rotate the grab shell 7. It has 13 and 14, a lever connecting position 22 on the opposite side of the cutting blade 21 of the grab shell 7, and an operating lever 15 for connecting the cutting blade rotating means 13 and 14, and the operating lever 15 rises. It is said that the grab shell 7 rotates inwardly and the cutting blade 21 cuts an underground obstacle.

The underground pile cutting device shown in Patent Document 2 is attached to a casing driver, a casing 5 rotationally driven by the casing driver, and an inner wall of the casing 5 so as to be openable and closable, and has an arcuate horizontal cross-sectional shape. A plurality of excavated bodies 20 having excavated bodies 22 on the lower side, and a hydraulic cylinder 23 vertically attached to the upper part of the excavated body 20 on the inner wall of the casing 5 to open and close the corresponding excavated body 21. Has been done.

Japanese Unexamined Patent Publication No. 2016-176263 JP-A-2007-162435

However, in the underground obstacle removing device of Patent Document 1, the grab holding portion 5, the grab shell 7, the cutting blade rotating means 13, 14 and the operating lever 15 are integrally equipped, and these are used for the removal work. Since it is housed and fixed in the tubular casing 100, the work is complicated, and even if the head side of the underground obstacle is made to enter the tubular casing 100, the amount of entry is the grab shell. It is limited to the distance between 7 and the grab holding portion 5 located above it, and the length of the pile to be cut is also short. For example, if the required cutting length is long, what kind of cutting work is required? It is necessary to repeat the process several times, which causes problems that the work efficiency is poor and the cost of cutting and removing the pile is high.

Further, since the cutting blade 21 of the grab shell 7 is a plurality of chip-shaped cutting blades provided along the leading edge of the grab shell 7, there is a possibility that the reinforcing bar embedded in the pile is left uncut. However, in such a case, it is necessary to temporarily stop the cutting work, pull up the tubular casing 100, and cut the reinforcing bar by another appropriate method, and the work efficiency is poor due to the setup change during the work. There was also the problem that the cost of cutting and removing piles was high.

On the other hand, in the underground pile cutting device of Patent Document 2, since the plurality of excavated bodies 20 and the hydraulic cylinder 23 for opening and closing the excavated body 20 are arranged on the inner wall side of the casing 5, these are arranged. In order to secure the arrangement space and the working space, the outer diameter of the pile cut in the casing 5 becomes smaller than the inner diameter of the casing 5, and as a result, the cost performance of the entire device is low, and the pile is extended. There was a problem that the cutting removal cost was high.

Therefore, in view of the above problems, it is an object of the present invention to provide an existing pile cutting / removing device capable of accurate cutting / removing while keeping the cutting / removing cost of piles low.

In the present invention, the following configuration is adopted as a specific means for solving such a problem.

In the first invention of the present application, an excavation blade and a cutting mechanism are provided at the lower end of a casing having an inner diameter larger than that of an existing pile and suspended and supported via an auger, and the upper end of the casing is cut. In an existing pile cutting / removing device provided with a driving mechanism for driving the mechanism, the cutting mechanism is a rocking body arranged inside the casing, and a plate material having a predetermined width is formed into a substantially semicircular shape. At the same time, both ends in the circumferential direction are pivotally supported by a pivot shaft provided at a position coaxially above the chord direction of the casing, and the drive mechanism moves in a direction around the pivot shaft so as to be in contact with and separated from the axis of the casing. An oscillating body to be oscillated, and a first bit detachably attached to an end edge of the oscillating body near the axis of the casing in a state of extending forward in the oscillating direction from the end edge. It is characterized in that a second bit attached to the inner surface of the rocking body in an extended state in the width direction of the rocking body is provided.

In the second invention of the present application, in the existing pile cutting / removing device according to the first invention, the rocking body has the first bit retracted toward the inner circumference of the casing to retract the inner peripheral surface and the existing pile. The non-operating position that stands by in the gap between the outer peripheral surface and the operating position and the operating position in which the first bit extends toward the center of the casing swings forward and backward, and at the operating position, the above-mentioned. It is characterized in that the cut portion of the existing pile can be supported from the lower side by the rocking body and the first bit.

The third invention of the present application is characterized in that, in the existing pile cutting / removing device according to the first or second invention, the second bit is detachably attached on the inner surface of the rocking body.

The fourth invention of the present application is characterized in that, in the existing pile cutting / removing device according to the first, second or third invention, a plurality of the cutting mechanisms are arranged in the circumferential direction of the casing.

In the fifth invention of the present application, in the existing pile cutting / removing device according to the first, second, third or third invention, the four drive mechanisms are provided with the hydraulic cylinder arranged on the upper part of the casing and the cutting. It is characterized in that it is provided with a cam body arranged in the vicinity of the mechanism and a rod for transmitting the operating force of the hydraulic cylinder to the cam body.

(A) First Invention of the present application According to the existing pile cutting / removing device according to the first invention of the present application, the rocking body is swung and advanced toward the center of the casing by the driving mechanism, and the first bit and the rocking body are moved forward. By rotating the casing with the auger while pressing the second bit against the outer peripheral surface of the existing pile, the concrete portion of the existing pile is gradually cut from the outer peripheral side when it is a PC pile. Further, the reinforcing bar portion and the concrete portion near the inner circumference are sequentially cut and cut.

In this case, the reinforcing bar may not be completely cut by the first bit, but may be pushed by the rotation of the first bit and gradually deformed toward the center of the pile to escape. In such a case, the first bit may be used. Since one bit extends from the edge portion of the rocking body toward the center of the existing pile, the extending portion of the first bit is caught by the reinforcing bar and rotates integrally with the casing in this state. By doing so, the reinforcing bar is gradually twisted.

Further, if the cutting with the first bit progresses and the first bit cuts into the center side of the existing pile, it interferes with the uncut portion of the existing pile and further cutting progress is hindered. In this case, the second bit attached in the width direction of the rocking body sequentially cuts the portion above the notch portion of the first bit, whereby the notch space of the first bit is secured. The cutting work by the first bit can be continued.

Further, since the first bit is detachably attached to the rocking body, for example, the number of the first bits installed can be changed according to the diameter of the existing pile to improve the efficiency of the pile cutting work. You can also plan.

As described above, regardless of whether or not the reinforcing bar is cut by the cutting action of the first bit, the existing pile is surely cut by the cutting mechanism, and the portion above the cut portion is the same. It will be separated from the remaining part buried in the soil on the lower side, for example, compared to the case where the cutting of the reinforcing bar part needs to be performed in a separate process from the cutting of the concrete part as in the conventional equipment. Therefore, the cutting work efficiency is high and the construction cost can be reduced.

(B) Second Invention of the present application According to the existing pile cutting / removing device according to the second invention of the present application, the following peculiar effects can be obtained in addition to the effects described in the above (a). That is, in the present invention, the rocking body is set to a non-operating position in which the first bit retracts toward the inner circumference of the casing and stands by at the gap between the inner peripheral surface and the outer peripheral surface of the existing pile. The first bit swings forward and backward between the operating positions extending toward the center of the casing, and at the operating position, the portion of the existing pile cut by the rocking body and the first bit. Since it is configured so that it can be supported from the lower side thereof, the rocking body is set to the operating position and the cutting work of the existing pile is performed, and the upper part from this cut portion (hereinafter, "cutting"). After separating the "pile") from the remaining buried portion below it (hereinafter referred to as "residual pile"), by pulling up the casing, the rocking body and the first bit from the lower side thereof. The supported excision pile will be pulled up and removed integrally with the casing. That is, in the cutting / removing device of the present invention, a series of operations from cutting an existing pile to removing a cut pile are continuously performed using the same device without performing setup change during the work. It can be carried out accurately and accurately, and it is possible to further reduce the construction cost in the pile cutting and removing work.

(C) Third Invention of the present application According to the existing pile cutting / removing device according to the third invention of the present application, in addition to the effects described in the above (a) or (b), the following peculiar effects are obtained. can get. That is, in the present invention, since the second bit is detachably attached on the inner surface of the rocking body, the first bit is from the pile surface of the first bit, for example, as in the case where the existing pile is a steel pipe pile. When the required bite amount is small, unnecessary cutting work by the second bit can be avoided by removing the second bit.

(D) Fourth Invention of the present application According to the existing pile cutting / removing device according to the fourth invention of the present application, in addition to the effects described in the above (a), (b) or (c), the following A unique effect can be obtained. That is, in the present invention, since a plurality of the cutting mechanisms are arranged in the circumferential direction of the casing, the pressing force on the existing pile at the time of cutting the existing pile is equalized as much as possible and cuts. The rolling vibration of the casing due to the work is suppressed, the quietness of the cutting work is promoted, and it is extremely effective especially in the work in the urban area.

(E) Fifth Invention of the present application According to the existing pile cutting / removing device according to the fifth invention of the present application, in addition to the effects described in the above (a), (b) or (c), the following A unique effect can be obtained. That is, in the present invention, the drive mechanism is a hydraulic cylinder arranged in the upper part of the casing, a cam body arranged in the vicinity of the cutting mechanism, and a rod for transmitting the operating force of the hydraulic cylinder to the cam body. Since it is a mechanical configuration equipped with the above, it is possible to provide a device having high operational reliability and excellent durability.

It is an whole view of the cutting removal apparatus of the existing pile which concerns on embodiment of this invention. It is a partial cross-sectional enlarged view of the part A of FIG. It is an enlarged external view of the part B of FIG. It is an enlarged sectional view which shows the state in the non-operation of the cutting mechanism part. FIG. 4 is a view taken along the line CC of FIG. It is an enlarged sectional view which shows the state at the time of operation of the cutting mechanism part. FIG. 6 is a view taken along the line DD of FIG. It is explanatory drawing of the cutting state of the PC pile. It is explanatory drawing of the cutting state of the place pile. It is explanatory drawing of the cutting state of a steel pipe pile. It is a front view of the 1st bit. FIG. 11 is a view taken along the line EE of FIG.

"Overall configuration of the existing pile cutting and removing device Z"
FIG. 1 shows an existing pile cutting / removing device Z according to an embodiment of the present invention. The cutting / removing device Z is configured by connecting the casing 1 to the lower side of the auger 3 suspended and supported by a support base such as a leader via a swivel joint 2.

The casing 1 is composed of a tubular body having an inner diameter (for example, about 500 mm to 600 mm) larger than the existing pile to be cut and removed by a predetermined dimension, and in this embodiment, the casing 1 is sequentially connected coaxially. It has a three-divided structure including an upper casing 11, an intermediate casing 12, and a lower casing 13, and the upper end of the upper casing 11 is connected to the lower side of the swivel joint 2.

Then, the casing 1 is driven into the soil along the existing pile 4 (see FIGS. 4 and 5) while being rotated by the auger 3 and is driven into the soil along the existing pile 4 (see FIGS. 4 and 5). At the lower end of the lower casing 13 located at the lowermost end, as shown in an enlarged view in FIG. 3, a plurality of tip excavation blades 14 attached to the lower end peripheral wall and a lower end peripheral circumference A plurality of outer drilling blades 15 mounted radially outward in a protruding state are provided.

Then, the soil in contact with the outer periphery of the existing pile 4 is cut by each of the tip excavation blades 14 at a position appropriately separated from the outer periphery, and edge cutting is performed. Further, the outer portion of the edge cutting portion is excavated in an annular shape having a predetermined width by the plurality of outer excavation blades 15, and a traveling gap of a guide case 34 described later provided on the outer periphery of the lower end of the lower casing 13 is formed. Reference numeral 17 is a spiral blade for discharging excavated soil.

Although not shown here, in reality, a jet nozzle is provided on the tip end side of the lower casing 13, and water supplied from the upper end side of the casing 1 is supplied from the jet nozzle to the lower casing 13. The excavation work is performed by the tip excavation blade 14 and the outer excavation blade 15 while jetting in the vicinity of the tip to promote the collapse of the soil.

Further, in the casing 1, the existing pile 4 is cut after the casing 1 is driven around the existing pile 4 to a predetermined depth, and after the cutting, the cut pile is supported from below as a pile support mechanism. A cutting mechanism 30 that also functions and a driving mechanism 19 that drives the cutting mechanism 30 are provided. Hereinafter, the cutting mechanism 30 and the driving mechanism 19 will be described respectively.

"Cut mechanism 30"
As shown in FIGS. 4 to 7, the cutting mechanism 30 has a swing body 44 attached to an inner peripheral surface near the lower end of the lower casing 13 and a swing lever connected to the center of the outer periphery of the swing body 44. The 41 is provided with a cam body 33 provided in the lower casing 13 so as to be engaged with the swing lever 41. In this embodiment, the cutting mechanism 30 is arranged at two positions facing each other with the axial center of the lower casing 13 interposed therebetween.

As shown in FIGS. 4 to 7, the rocking body 44 is formed by bending a plate material having a predetermined width into a substantially semicircular shape along the inner surface of the lower casing 13, and both ends thereof are respectively. It is formed so as to extend diagonally upward. Then, as shown in FIG. 5, the rocking body 44 has both ends thereof at the center of one of the two center lines L _b and L _c extending in the orthogonal direction through the axis of the lower casing 13. It is swingably supported by a pair of pivot shafts 43 arranged on the pivot axis L _d separated in parallel with the line L _b by a predetermined interval.

Therefore, as shown in FIG. 4, the rocking body 44 has a position where the outer surface thereof is substantially parallel to the inner surface of the lower casing 13 (hereinafter, the position of the rocking body 44 at this time is referred to as a “non-operating position”). As shown in FIG. 6, the lower casing 13 is _{swung toward} the axis La and is close to the axis La (hereinafter, the position of the rocking body 44 at this time is referred to as an “operating position”). It is possible to swing with.

Further, one end of the swing lever 41 is pivotally supported by a connecting pin 42 on the outer surface of the swing body 44 on the center line _Lc . The other end of the swing lever 41 is connected to the lower rod 23 of the drive mechanism 19 described later via a pivot pin 32 that moves in the vertical direction along the guide slot 35 provided on the guide case 34 side. There is. Further, the lower edge portion of the opening 18 of the lower casing 13 is provided with a cam body 33 that is slidably engaged with a cam surface formed on the peripheral surface on one end side of the rocking body 44.

At its "first position", the swing lever 41 is pulled upward by the lower rod 23 as shown in FIG. 4, and the entire swing lever 41 is housed inside the guide case 34. ing. At this time, the cam surface on one end side of the swing lever 41 is in contact with or closely opposed to the upper edge portion of the cam body 33, and is connected to one end side of the swing lever 41 by the connecting pin 42. The rocking body 44 is set to the "non-operating position".

Further, in the "second position" of the swing lever 41, as shown in FIG. 6, the lower rod 23 pushes the swing lever downward downward, and the cam surface on the lower end side thereof is the lower edge portion of the cam body 33. The lower half portion thereof is pushed out toward the center of the lower casing 13 by sliding contact with the lower casing 13. In response to the displacement of the swing lever 41, the swing body 44 swings and displaces toward the center of the lower casing 13 with the pivot shaft 43 as the center, and is positioned at the "operating position".

Further, the first bit 51 and the second bit 52 described below are attached to the rocking body 44.

As shown in FIGS. 11 and 12, the first bit 51 has a substantially rectangular block-like shape in which one surface is inclined, and a cemented carbide cutting edge 51c is provided in a portion from the inclined surface to the bottom surface. It is configured to include a main body portion 51a provided, and two plate-shaped fixing portions 51b standing at a position far from the cutting edge 51c of the main body portion and having a bolt fixing hole 51d. Therefore, in the first bit 51, the cutting edge 51c portion is in a state of extending diagonally downward with respect to the fixing portion 51b. The first bit 51 has a high cutting ability particularly for both concrete and metal materials.

As shown in FIGS. 4 and 5, the first bit 51 is appropriately separated from the position on the center line L _c of the rocking body 44 and the position on the center line L _c on both sides in the circumferential direction. In the total of three positions of the two positions, the receiving portion 44a (see FIGS. 11 and 12) provided at the end edge portion of the _rocking body 44 on the front side in the swing direction (that is, near the axis La of the lower casing 13). ), And the fixing portion 51b is fitted and fastened with a fixing bolt. There is.

In this embodiment, as described above, three first bits 51 are arranged radially with respect to one _rocking body 44 so as to be directed to the axis La of the lower casing 13. The invention is not limited to this, and for example, it is possible to increase or decrease the amount according to various conditions such as the type of the existing pile to be cut and the diameter dimension.

On the other hand, the second bit 52 has a triangular columnar shape having a length substantially matching the width dimension of the rocking body 44, and one ridgeline portion thereof is used as a cutting edge. Then, the second bit 52 is welded onto the inner surface of the rocking body 44 in a state where the surface facing the cutting edge is abutted against the inner surface of the rocking body 44 in the axial direction of the rocking body 44. It is fixed.

In this embodiment, the second bit 52 is welded and fixed on the inner surface of the rocking body 44, but in other embodiments, the second bit 52 is mounted on the inner surface of the rocking body 44. It is also possible to configure it so that it can be detachably fixed to the.

The rocking body 44 configured in this way swings "between the non-operating state position" and the "operating position" in response to the displacement of the swing lever 41 driven by the drive mechanism 19 described later. By displacing, the existing pile 4 is cut by the first bit 51 and the second bit 52.

"Drive mechanism 19"
As shown in FIGS. 1 and 2, the drive mechanism 19 includes a hydraulic cylinder 20 attached to the upper end side of the upper casing 11 of the casing 1, and a swing lever on the hydraulic cylinder 20 and the cutting mechanism 30 side. It is configured to include a rod 21 for connecting the 41. Further, the rod 21 has a two-divided structure of an upper rod 22 made of a round bar and a lower rod 23 made of a square bar, and the lower end of the lower rod 23 is connected to the swing lever 41. ..

In this embodiment, corresponding to the provision of two sets of the cutting mechanisms 30, the drive mechanism 19 is also provided at two positions sandwiching the axial center of the casing 1 in the radial direction. .. Then, the swing lever 41 on the cutting mechanism 30 side operates in response to the expansion / contraction movement of the hydraulic cylinder 20, so that the swing body 44 swings between the “non-operating position” and the “operating position”. Moved in and out.

"Explanation of operation of cutting removal device Z"
Here, the operating state related to the cutting and removal of the existing pile 4 by the cutting / removing device Z will be described.

A: Preliminary work First, the cutting / removing device Z is suspended and supported on a support base such as a reader, and is positioned and arranged directly above the existing pile 4 to be worked. Then, the hydraulic cylinder 20 of the drive mechanism 19 is reduced, and the rocking body 44 of the cutting mechanism 30 is set to the “non-operating position”. Here, as the existing pile 4, a hollow cylindrical PC pile or a PHC pile is assumed.

B: Excavation work Next, the auger 3 is driven to rotate the casing 1 while lowering the casing 1, and the casing 1 is descended while excavating the periphery of the existing pile 4 located inside the casing 1 in an enclosed state. Let me. Then, when the cutting mechanism 30 reaches the target cutting position of the existing pile 4, the descent of the casing 1 is stopped. At this point, the pair of left and right cutting mechanisms 30 are positioned at the “non-operating position” shown in FIG. 4, and both the first bit 51 and the second bit 52 of the rocking body 44 are the existing piles 4. Maintains a non-contact state with respect to the outer peripheral surface of the.

C: Cutting work Next, while rotating the casing 1, the hydraulic cylinder 20 of the drive mechanism 19 is extended, and the rocking body 44 is "operated" from the "non-operating position" via the swing lever 41. It is changed to the "time position" side, and the first bit 51 and the second bit 52 are pressed and urged on the outer peripheral surface of the existing pile 4. Then, the existing pile 4 is cut from the outer peripheral surface of the existing pile 4 in the axial direction by the first bit 51, and a cutting groove is formed that goes around the outer periphery of the existing pile 4, and the first bit 51 is cut. As the process progresses, it immerses itself in the cutting groove (see the cutting surface P _b in FIG. 8). When the amount of immersion of the first bit 51 into the cutting groove reaches a predetermined amount, the second bit 52 is pressed against the upper portion of the cutting groove, and the upper portion of the cutting groove is directed upward by the second bit 52. It is cut in an inclined shape (see the cutting surface _Pa in FIG. 8), the cutting space of the first bit 51 is secured, and the cutting work by the first bit 51 can be continued.

Along with the progress of cutting of the existing pile 4 by the first bit 51, the first bit 51 reaches and cuts the vertical bar 5 and the horizontal bar 6 in which the first bit 51 is embedded, and further closer to the center than the vertical bar 5 and the horizontal bar 6. Cut the concrete part in. Then, when the first bit 51 reaches the inner peripheral surface of the existing pile 4, the existing pile 4 is cut into a cut pile 4B above the cutting portion and a remaining pile 4 below it. Will be done.

Although it is a rare case, depending on the conditions such as working conditions, the vertical bar 5 or the horizontal bar 6 is not completely cut by the first bit 51, and is pushed by the rotation of the first bit 51 to gradually pile up. It can also occur that it deforms toward the center and escapes. However, in such a case, since the first bit 51 extends from the edge portion of the rocking body 44 toward the center of the existing pile 4, the extending portion of the first bit 51 extends to the reinforcing bar 5 and the reinforcing bar 5. By being caught in the horizontal bar 6 and rotating integrally with the casing 1 in this state, the reinforcing bar 5 and the horizontal bar 6 are forcibly twisted and cut in the same manner as in the case of being cut by the first bit 51. Since the state is obtained, no problem arises. That is, the existing pile 4 is surely cut by the cutting mechanism 30 without being influenced by the cutting form of the vertical bar 5 and the horizontal bar 6.

D: Removal work of the cut pile 4B When the existing pile 4 is cut at a predetermined position and divided into the remaining pile 4A and the cut pile 4B, the rotation of the casing 1 is stopped and the shaking of the cutting mechanism 30 is performed. The moving body 44 is held in the "operating position". In this state, the excised pile 4B is held in a state of being supported from below by the rocking body 44 itself and the first bit 51 attached to the rocking body 44 itself. Therefore, if the casing 1 is pulled up as it is, the cut pile 4B is removed from the excavation hole integrally with the casing 1.

E: Cutting and removal work when the existing pile 4 is a solid cast-in-place pile In this case as well, the cutting work of the existing pile 4 and the removal work of the cut pile 4B are the PC pile in which the existing pile 4 is hollow. It is basically the same as the case of PHC piles, and the cutting work for the PC piles and PHC piles is only continued until near the center of the pile axis, and the same applies to the cutting for the vertical and horizontal bars. That is, as shown in FIG. 9, in the cut pile 4B, a large substantially truncated cone portion (see cutting surface Pa) concave portion is formed in the cut portion, and in the remaining pile 4A, the concave portion (cutting surface) is formed in the cut portion. See Pb) is formed. Therefore, the cutting and removing device Z can be used to remove the cutting pile 4B without any problem.

F: Cutting and removing work when the existing pile 4 is a steel pipe pile Cutting and removing work when the existing pile 4 is a steel pipe pile Also in this case, basically, cutting work and cutting pile of the existing pile 4 The removal work of 4B is the same as when the existing pile 4 is a hollow PC pile or PHC pile or a cast-in-place pile, but in the case of a steel pipe pile, the cutting depth is the PC pile or PHC. Since it is smaller than piles and cast-in-place piles, specific measures are required.

That is, in the case of steel pipe piles, the pipe wall thickness is smaller than in the case of PC piles or PHC piles, and the pile cutting work is completed at the stage where the depth of cut of the first bit 51 is small. There is almost no need to secure the cut space of the first bit 51 by the second bit 52 as in the case of a pile. Therefore, the second bit 52 is configured to be detachably attached to the rocking body 44 in advance, and as shown in FIG. 10, the second bit 52 is attached to the steel pipe pile when cutting the steel pipe pile. It is preferable that the steel pipe pile is cut by removing it from the rocking body 44 and using only the first bit 51. By doing so, on the cut pile 4B side, the cutting surface Pa approaches a plane substantially orthogonal to the axis of the steel pipe as much as possible, and unnecessary cutting parts are eliminated, so that the workability of the cutting work as a whole is improved. It will be improved.

G: Others (1) In the above embodiment, the cutting / removing device Z is provided with a pair of left and right cutting mechanisms 30, but the present invention is not limited to such a configuration, and for example, the cutting mechanism. It can be applied to the one provided with only one 30 and the one provided with three or more.

The existing pile cutting / removing device according to the present invention can be widely used for cutting / removing existing piles in civil engineering and construction work.

1 ・ ・ Casing 2 ・ ・ Swivel joint 3 ・ ・ Auger 4 ・ ・ Existing pile 5 ・ ・ Vertical bar 6 ・ ・ Horizontal bar 14 ・ ・ Tip excavation blade 15 ・ ・ Outer excavation blade 17 ・ ・ Spiral blade 18 ・ ・ Opening 19 ・・ Drive mechanism 20 ・ ・ Hydraulic cylinder 21 ・ ・ Rod 30 ・ ・ Cutting mechanism 32 ・ ・ Pit pin 33 ・ ・ Cam body 34 ・ ・ Guide case 41 ・ ・ Swing lever 42 ・ ・ Connecting pin 43 ・ ・ Pit shaft 44 ・ ・ Swinging body 51 ・ ・ 1st bit 52 ・ ・ 2nd bit 4A ・ ・ Remaining pile 4B ・ ・ Cutting pile Z ・ ・ Cutting and removing device

The present invention relates to an existing pile cutting / removing device that cuts and removes an existing pile buried in the soil from the upper side thereof.

As a method for removing existing piles buried in the soil, there are known a pull-out removal method in which the existing piles are integrally pulled out and removed, and a cutting and removal method in which the existing piles are cut and removed by a predetermined length from the upper end side thereof. Has been done. In particular, the latter is an effective method when it is not necessary to remove all the existing piles, only the part up to the predetermined depth on the ground surface side is removed, and it is sufficient to leave the part below it as it is, in terms of construction cost. In recent years, it has tended to be widely used due to the advantage of the above, and Patent Document 1 and Patent Document 2 show the construction method.

What is shown in Patent Document 1 is an underground obstacle removing device, which is arranged inside a tubular casing 100 that is built while rotating around an axis so as to surround the underground obstacle, and is a tubular casing. The grab holding portion 5 is formed in a semicircular shape having a pivot shaft 18 at both ends and a cutting blade 21 at the lower edge, and a grab holding portion 5 for digging and fitting between the inner circumference and the outer periphery of the underground obstacle. A pair of grab shells 7 rotatably arranged around the pivot shaft 18 at the bottom of 5, and a cutting blade rotating means provided above the grab shell 7 to rotate the grab shell 7. It has 13 and 14, a lever connecting position 22 on the opposite side of the cutting blade 21 of the grab shell 7, and an operating lever 15 for connecting the cutting blade rotating means 13 and 14, and the operating lever 15 rises. It is said that the grab shell 7 rotates inwardly and the cutting blade 21 cuts an underground obstacle.

The underground pile cutting device shown in Patent Document 2 is attached to a casing driver, a casing 5 rotationally driven by the casing driver, and an inner wall of the casing 5 so as to be openable and closable, and has an arcuate horizontal cross-sectional shape. A plurality of excavated bodies 20 having excavated bodies 22 on the lower side, and a hydraulic cylinder 23 vertically attached to the upper part of the excavated body 20 on the inner wall of the casing 5 to open and close the corresponding excavated body 21. Has been done.

Japanese Unexamined Patent Publication No. 2016-176263 JP-A-2007-162435

However, in the underground obstacle removing device of Patent Document 1, the grab holding portion 5, the grab shell 7, the cutting blade rotating means 13, 14 and the operating lever 15 are integrally equipped, and these are used for the removal work. Since it is housed and fixed in the tubular casing 100, the work is complicated, and even if the head side of the underground obstacle is made to enter the tubular casing 100, the amount of entry is the grab shell. It is limited to the distance between 7 and the grab holding portion 5 located above it, and the length of the pile to be cut is also short. For example, if the required cutting length is long, what kind of cutting work is required? It is necessary to repeat the process several times, which causes problems that the work efficiency is poor and the cost of cutting and removing the pile is high.

Further, since the cutting blade 21 of the grab shell 7 is a plurality of chip-shaped cutting blades provided along the leading edge of the grab shell 7, there is a possibility that the reinforcing bar embedded in the pile is left uncut. However, in such a case, it is necessary to temporarily stop the cutting work, pull up the tubular casing 100, and cut the reinforcing bar by another appropriate method, and the work efficiency is poor due to the setup change during the work. There was also the problem that the cost of cutting and removing piles was high.

On the other hand, in the underground pile cutting device of Patent Document 2, since the plurality of excavated bodies 20 and the hydraulic cylinder 23 for opening and closing the excavated body 20 are arranged on the inner wall side of the casing 5, these are arranged. In order to secure the arrangement space and the working space, the outer diameter of the pile cut in the casing 5 becomes smaller than the inner diameter of the casing 5, and as a result, the cost performance of the entire device is low, and the pile is extended. There was a problem that the cutting removal cost was high.

Therefore, in view of the above problems, it is an object of the present invention to provide an existing pile cutting / removing device capable of accurate cutting / removing while keeping the cutting / removing cost of piles low.

In the present invention, the following configuration is adopted as a specific means for solving such a problem.

In the first invention of the present application, an excavation blade and a cutting mechanism are provided at the lower end of a casing having an inner diameter larger than that of an existing pile and suspended and supported via an auger, and the upper end of the casing is cut. In an existing pile cutting / removing device provided with a driving mechanism for driving the mechanism, the cutting mechanism is a rocking body arranged inside the casing, and a plate material having a predetermined width is formed into a substantially semicircular shape. At the same time, both ends in the circumferential direction are pivotally supported by a pivot shaft provided at a position coaxially above the chord direction of the casing, and the drive mechanism moves in a direction around the pivot shaft so as to be in contact with and separated from the axis of the casing. An oscillating body to be oscillated, and a first bit detachably attached to an end edge of the oscillating body near the axis of the casing in a state of extending forward in the oscillating direction from the end edge. It is characterized in that a second bit attached to the inner surface of the rocking body in an extended state in the width direction of the rocking body is provided.

In the second invention of the present application, in the existing pile cutting / removing device according to the first invention, the rocking body has the first bit retracted toward the inner circumference of the casing to retract the inner peripheral surface and the existing pile. The non-operating position that stands by in the gap between the outer peripheral surface and the operating position and the operating position in which the first bit extends toward the center of the casing swings forward and backward, and at the operating position, the above-mentioned. It is characterized in that the cut portion of the existing pile can be supported from the lower side by the rocking body and the first bit.

The third invention of the present application is characterized in that, in the existing pile cutting / removing device according to the first or second invention, the second bit is detachably attached on the inner surface of the rocking body.

The fourth invention of the present application is characterized in that, in the existing pile cutting / removing device according to the first, second or third invention, a plurality of the cutting mechanisms are arranged in the circumferential direction of the casing.

In the fifth invention of the present application, in the existing pile cutting / removing device according to the first, second or third invention, the drive mechanism is provided with a hydraulic cylinder arranged on the upper part of the casing and the hydraulic cylinder. It is characterized by being provided with a rod for connecting the swing lever .

(A) First Invention of the present application According to the existing pile cutting / removing device according to the first invention of the present application, the rocking body is swung and advanced toward the center of the casing by the driving mechanism, and the first bit and the rocking body are moved forward. By rotating the casing with the auger while pressing the second bit against the outer peripheral surface of the existing pile, the concrete portion of the existing pile is gradually cut from the outer peripheral side when it is a PC pile. Further, the reinforcing bar portion and the concrete portion near the inner circumference are sequentially cut and cut.

In this case, the reinforcing bar may not be completely cut by the first bit, but may be pushed by the rotation of the first bit and gradually deformed toward the center of the pile to escape. In such a case, the first bit may be used. Since one bit extends from the edge portion of the rocking body toward the center of the existing pile, the extending portion of the first bit is caught by the reinforcing bar and rotates integrally with the casing in this state. By doing so, the reinforcing bar is gradually twisted.

Further, if the cutting with the first bit progresses and the first bit cuts into the center side of the existing pile, it interferes with the uncut portion of the existing pile and further cutting progress is hindered. In this case, the second bit attached in the width direction of the rocking body sequentially cuts the portion above the notch portion of the first bit, whereby the notch space of the first bit is secured. The cutting work by the first bit can be continued.

Further, since the first bit is detachably attached to the rocking body, for example, the number of the first bits installed can be changed according to the diameter of the existing pile to improve the efficiency of the pile cutting work. You can also plan.

As described above, regardless of whether or not the reinforcing bar is cut by the cutting action of the first bit, the existing pile is surely cut by the cutting mechanism, and the portion above the cut portion is the same. It will be separated from the remaining part buried in the soil on the lower side, for example, compared to the case where the cutting of the reinforcing bar part needs to be performed in a separate process from the cutting of the concrete part as in the conventional equipment. Therefore, the cutting work efficiency is high and the construction cost can be reduced.

(B) Second Invention of the present application According to the existing pile cutting / removing device according to the second invention of the present application, the following peculiar effects can be obtained in addition to the effects described in the above (a). That is, in the present invention, the rocking body is set to a non-operating position in which the first bit retracts toward the inner circumference of the casing and stands by at the gap between the inner peripheral surface and the outer peripheral surface of the existing pile. The first bit swings forward and backward between the operating positions extending toward the center of the casing, and at the operating position, the portion of the existing pile cut by the rocking body and the first bit. Since it is configured so that it can be supported from the lower side thereof, the rocking body is set to the operating position and the cutting work of the existing pile is performed, and the upper part from this cut portion (hereinafter, "cutting"). After separating the "pile") from the remaining buried portion below it (hereinafter referred to as "residual pile"), by pulling up the casing, the rocking body and the first bit from the lower side thereof. The supported excision pile will be pulled up and removed integrally with the casing. That is, in the cutting / removing device of the present invention, a series of operations from cutting an existing pile to removing a cut pile are continuously performed using the same device without performing setup change during the work. It can be carried out accurately and accurately, and it is possible to further reduce the construction cost in the pile cutting and removing work.

(C) Third Invention of the present application According to the existing pile cutting / removing device according to the third invention of the present application, in addition to the effects described in the above (a) or (b), the following peculiar effects are obtained. can get. That is, in the present invention, since the second bit is detachably attached on the inner surface of the rocking body, the first bit is from the pile surface of the first bit, for example, as in the case where the existing pile is a steel pipe pile. When the required bite amount is small, unnecessary cutting work by the second bit can be avoided by removing the second bit.

(D) Fourth Invention of the present application According to the existing pile cutting / removing device according to the fourth invention of the present application, in addition to the effects described in the above (a), (b) or (c), the following A unique effect can be obtained. That is, in the present invention, since a plurality of the cutting mechanisms are arranged in the circumferential direction of the casing, the pressing force on the existing pile at the time of cutting the existing pile is equalized as much as possible and cuts. The rolling vibration of the casing due to the work is suppressed, the quietness of the cutting work is promoted, and it is extremely effective especially in the work in the urban area.

(E) Fifth Invention of the present application According to the existing pile cutting / removing device according to the fifth invention of the present application, in addition to the effects described in the above (a), (b) or (c), the following A unique effect can be obtained. That is, in the present invention, the drive mechanism has a mechanical configuration including a hydraulic cylinder arranged on the upper part of the casing and a rod connecting the hydraulic cylinder and the swing lever . It is possible to provide a device having high reliability and excellent durability.

It is an whole view of the cutting removal apparatus of the existing pile which concerns on embodiment of this invention. It is a partial cross-sectional enlarged view of the part A of FIG. It is an enlarged external view of the part B of FIG. It is an enlarged sectional view which shows the state in the non-operation of the cutting mechanism part. FIG. 4 is a view taken along the line CC of FIG. It is an enlarged sectional view which shows the state at the time of operation of the cutting mechanism part. FIG. 6 is a view taken along the line DD of FIG. It is explanatory drawing of the cutting state of a PC pile. It is explanatory drawing of the cutting state of the place pile. It is explanatory drawing of the cutting state of a steel pipe pile. It is a front view of the 1st bit. FIG. 11 is a view taken along the line EE of FIG.

"Overall configuration of the existing pile cutting and removing device Z"
FIG. 1 shows an existing pile cutting / removing device Z according to an embodiment of the present invention. The cutting / removing device Z is configured by connecting the casing 1 to the lower side of the auger 3 suspended and supported by a support base such as a leader via a swivel joint 2.

The casing 1 is composed of a tubular body having an inner diameter (for example, about 500 mm to 600 mm) larger than the existing pile to be cut and removed by a predetermined dimension, and in this embodiment, the casing 1 is sequentially connected coaxially. It has a three-divided structure including an upper casing 11, an intermediate casing 12, and a lower casing 13, and the upper end of the upper casing 11 is connected to the lower side of the swivel joint 2.

Then, the casing 1 is driven into the soil along the existing pile 4 (see FIGS. 4 and 5) while being rotated by the auger 3 and is driven into the soil along the existing pile 4 (see FIGS. 4 and 5). At the lower end of the lower casing 13 located at the lowermost end, as shown in an enlarged view in FIG. 3, a plurality of tip excavation blades 14 attached to the lower end peripheral wall and a lower end peripheral circumference A plurality of outer drilling blades 15 mounted radially outward in a protruding state are provided.

Then, the soil in contact with the outer periphery of the existing pile 4 is cut by each of the tip excavation blades 14 at a position appropriately separated from the outer periphery, and edge cutting is performed. Further, the outer portion of the edge cutting portion is excavated in an annular shape having a predetermined width by the plurality of outer excavation blades 15, and a traveling gap of a guide case 34 described later provided on the outer periphery of the lower end of the lower casing 13 is formed. Reference numeral 17 is a spiral blade for discharging excavated soil.

Although not shown here, in reality, a jet nozzle is provided on the tip end side of the lower casing 13, and water supplied from the upper end side of the casing 1 is supplied from the jet nozzle to the lower casing 13. The excavation work is performed by the tip excavation blade 14 and the outer excavation blade 15 while jetting in the vicinity of the tip to promote the collapse of the soil.

Further, in the casing 1, the existing pile 4 is cut after the casing 1 is driven around the existing pile 4 to a predetermined depth, and after the cutting, the cut pile is supported from below as a pile support mechanism. A cutting mechanism 30 that also functions and a driving mechanism 19 that drives the cutting mechanism 30 are provided. Hereinafter, the cutting mechanism 30 and the driving mechanism 19 will be described respectively.

"Cut mechanism 30"
As shown in FIGS. 4 to 7, the cutting mechanism 30 has a swing body 44 attached to an inner peripheral surface near the lower end of the lower casing 13 and a swing lever connected to the center of the outer periphery of the swing body 44. The 41 is provided with a cam body 33 provided in the lower casing 13 so as to be engaged with the swing lever 41. In this embodiment, the cutting mechanism 30 is arranged at two positions facing each other with the axial center of the lower casing 13 interposed therebetween.

As shown in FIGS. 4 to 7, the rocking body 44 is formed by bending a plate material having a predetermined width into a substantially semicircular shape along the inner surface of the lower casing 13, and both ends thereof are respectively. It is formed so as to extend diagonally upward. Then, as shown in FIG. 5, the rocking body 44 has both ends thereof at the center of one of the two center lines L _b and L _c extending in the orthogonal direction through the axis of the lower casing 13. It is swingably supported by a pair of pivot shafts 43 arranged on the pivot axis L _d separated in parallel with the line L _b by a predetermined interval.

Therefore, as shown in FIG. 4, the rocking body 44 has a position where the outer surface thereof is substantially parallel to the inner surface of the lower casing 13 (hereinafter, the position of the rocking body 44 at this time is referred to as a “non-operating position”). As shown in FIG. 6, the lower casing 13 is _{swung toward} the axis La and is close to the axis La (hereinafter, the position of the rocking body 44 at this time is referred to as an “operating position”). It is possible to swing with.

Further, one end of the swing lever 41 is pivotally supported by a connecting pin 42 on the outer surface of the swing body 44 on the center line _Lc . The other end of the swing lever 41 is connected to the lower rod 23 of the drive mechanism 19 described later via a pivot pin 32 that moves in the vertical direction along the guide slot 35 provided on the guide case 34 side. There is. Further, the lower edge portion of the opening 18 of the lower casing 13 is provided with a cam body 33 that is slidably engaged with a cam surface formed on the peripheral surface on one end side of the rocking body 44.

At its "first position", the swing lever 41 is pulled upward by the lower rod 23 as shown in FIG. 4, and the entire swing lever 41 is housed inside the guide case 34. ing. At this time, the cam surface on one end side of the swing lever 41 is in contact with or closely opposed to the upper edge portion of the cam body 33, and is connected to one end side of the swing lever 41 by the connecting pin 42. The rocking body 44 is set to the "non-operating position".

Further, in the "second position" of the swing lever 41, as shown in FIG. 6, the lower rod 23 pushes the swing lever downward downward, and the cam surface on the lower end side thereof is the lower edge portion of the cam body 33. The lower half portion thereof is pushed out toward the center of the lower casing 13 by sliding contact with the lower casing 13. In response to the displacement of the swing lever 41, the swing body 44 swings and displaces toward the center of the lower casing 13 with the pivot shaft 43 as the center, and is positioned at the "operating position".

Further, the first bit 51 and the second bit 52 described below are attached to the rocking body 44.

As shown in FIGS. 11 and 12, the first bit 51 has a substantially rectangular block-like shape in which one surface is inclined, and a cemented carbide cutting edge 51c is provided in a portion from the inclined surface to the bottom surface. It is configured to include a main body portion 51a provided, and two plate-shaped fixing portions 51b standing at a position far from the cutting edge 51c of the main body portion and having a bolt fixing hole 51d. Therefore, in the first bit 51, the cutting edge 51c portion is in a state of extending diagonally downward with respect to the fixing portion 51b. The first bit 51 has a high cutting ability particularly for both concrete and metal materials.

As shown in FIGS. 4 and 5, the first bit 51 is appropriately separated from the position on the center line L _c of the rocking body 44 and the position on the center line L _c on both sides in the circumferential direction. In the total of three positions of the two positions, the receiving portion 44a (see FIGS. 11 and 12) provided at the end edge portion of the _rocking body 44 on the front side in the swing direction (that is, near the axis La of the lower casing 13). ), And the fixing portion 51b is fitted and fastened with a fixing bolt. There is.

In this embodiment, as described above, three first bits 51 are arranged radially with respect to one _rocking body 44 so as to be directed to the axis La of the lower casing 13. The invention is not limited to this, and for example, it is possible to increase or decrease the amount according to various conditions such as the type of the existing pile to be cut and the diameter dimension.

On the other hand, the second bit 52 has a triangular columnar shape having a length substantially matching the width dimension of the rocking body 44, and one ridgeline portion thereof is used as a cutting edge. Then, the second bit 52 is welded onto the inner surface of the rocking body 44 in a state where the surface facing the cutting edge is abutted against the inner surface of the rocking body 44 in the axial direction of the rocking body 44. It is fixed.

In this embodiment, the second bit 52 is welded and fixed on the inner surface of the rocking body 44, but in other embodiments, the second bit 52 is mounted on the inner surface of the rocking body 44. It is also possible to configure it so that it can be detachably fixed to the.

The rocking body 44 configured in this way swings "between the non-operating state position" and the "operating position" in response to the displacement of the swing lever 41 driven by the drive mechanism 19 described later. By displacing, the existing pile 4 is cut by the first bit 51 and the second bit 52.

"Drive mechanism 19"
As shown in FIGS. 1 and 2, the drive mechanism 19 includes a hydraulic cylinder 20 attached to the upper end side of the upper casing 11 of the casing 1, and a swing lever on the hydraulic cylinder 20 and the cutting mechanism 30 side. It is configured to include a rod 21 for connecting the 41. Further, the rod 21 has a two-divided structure of an upper rod 22 made of a round bar and a lower rod 23 made of a square bar, and the lower end of the lower rod 23 is connected to the swing lever 41. ..

In this embodiment, corresponding to the provision of two sets of the cutting mechanisms 30, the drive mechanism 19 is also provided at two positions sandwiching the axial center of the casing 1 in the radial direction. .. Then, the swing lever 41 on the cutting mechanism 30 side operates in response to the expansion / contraction movement of the hydraulic cylinder 20, so that the swing body 44 swings between the “non-operating position” and the “operating position”. Moved in and out.

"Explanation of operation of cutting removal device Z"
Here, the operating state related to the cutting and removal of the existing pile 4 by the cutting / removing device Z will be described.

A: Preliminary work First, the cutting / removing device Z is suspended and supported on a support base such as a reader, and is positioned and arranged directly above the existing pile 4 to be worked. Then, the hydraulic cylinder 20 of the drive mechanism 19 is reduced, and the rocking body 44 of the cutting mechanism 30 is set to the “non-operating position”. Here, as the existing pile 4, a hollow cylindrical PC pile or a PHC pile is assumed.

B: Excavation work Next, the auger 3 is driven to rotate the casing 1 while lowering the casing 1, and the casing 1 is descended while excavating the periphery of the existing pile 4 located inside the casing 1 in an enclosed state. Let me. Then, when the cutting mechanism 30 reaches the target cutting position of the existing pile 4, the descent of the casing 1 is stopped. At this point, the pair of left and right cutting mechanisms 30 are positioned at the “non-operating position” shown in FIG. 4, and both the first bit 51 and the second bit 52 of the rocking body 44 are the existing piles 4. Maintains a non-contact state with respect to the outer peripheral surface of the.

C: Cutting work Next, while rotating the casing 1, the hydraulic cylinder 20 of the drive mechanism 19 is extended, and the rocking body 44 is "operated" from the "non-operating position" via the swing lever 41. It is changed to the "time position" side, and the first bit 51 and the second bit 52 are pressed and urged on the outer peripheral surface of the existing pile 4. Then, the existing pile 4 is cut from the outer peripheral surface of the existing pile 4 in the axial direction by the first bit 51, and a cutting groove is formed that goes around the outer periphery of the existing pile 4, and the first bit 51 is cut. As the process progresses, it immerses itself in the cutting groove (see the cutting surface P _b in FIG. 8). When the amount of immersion of the first bit 51 into the cutting groove reaches a predetermined amount, the second bit 52 is pressed against the upper portion of the cutting groove, and the upper portion of the cutting groove is directed upward by the second bit 52. It is cut in an inclined shape (see the cutting surface _Pa in FIG. 8), the cutting space of the first bit 51 is secured, and the cutting work by the first bit 51 can be continued.

Along with the progress of cutting of the existing pile 4 by the first bit 51, the first bit 51 reaches and cuts the vertical bar 5 and the horizontal bar 6 in which the first bit 51 is embedded, and further closer to the center than the vertical bar 5 and the horizontal bar 6. Cut the concrete part in. Then, when the first bit 51 reaches the inner peripheral surface of the existing pile 4, the existing pile 4 is cut into a cut pile 4B above the cutting portion and a remaining pile 4 below it. Will be done.

Although it is a rare case, depending on the conditions such as working conditions, the vertical bar 5 or the horizontal bar 6 is not completely cut by the first bit 51, and is pushed by the rotation of the first bit 51 to gradually pile up. It can also occur that it deforms toward the center and escapes. However, in such a case, since the first bit 51 extends from the edge portion of the rocking body 44 toward the center of the existing pile 4, the extending portion of the first bit 51 extends to the reinforcing bar 5 and the reinforcing bar 5. By being caught in the horizontal bar 6 and rotating integrally with the casing 1 in this state, the reinforcing bar 5 and the horizontal bar 6 are forcibly twisted and cut in the same manner as in the case of being cut by the first bit 51. Since the state is obtained, no problem arises. That is, the existing pile 4 is surely cut by the cutting mechanism 30 without being influenced by the cutting form of the vertical bar 5 and the horizontal bar 6.

D: Removal work of the cut pile 4B When the existing pile 4 is cut at a predetermined position and divided into the remaining pile 4A and the cut pile 4B, the rotation of the casing 1 is stopped and the shaking of the cutting mechanism 30 is performed. The moving body 44 is held in the "operating position". In this state, the excised pile 4B is held in a state of being supported from below by the rocking body 44 itself and the first bit 51 attached to the rocking body 44 itself. Therefore, if the casing 1 is pulled up as it is, the cut pile 4B is removed from the excavation hole integrally with the casing 1.

E: Cutting and removal work when the existing pile 4 is a solid cast-in-place pile In this case as well, the cutting work of the existing pile 4 and the removal work of the cut pile 4B are the PC pile in which the existing pile 4 is hollow. It is basically the same as the case of PHC piles, and the cutting work for the PC piles and PHC piles is only continued until near the center of the pile axis, and the same applies to the cutting for the vertical and horizontal bars. That is, as shown in FIG. 9, in the cut pile 4B, a large substantially truncated cone portion (see cutting surface Pa) concave portion is formed in the cut portion, and in the remaining pile 4A, the concave portion (cutting surface) is formed in the cut portion. See Pb) is formed. Therefore, the cutting and removing device Z can be used to remove the cutting pile 4B without any problem.

F: Cutting and removing work when the existing pile 4 is a steel pipe pile Cutting and removing work when the existing pile 4 is a steel pipe pile Also in this case, basically, cutting work and cutting pile of the existing pile 4 The removal work of 4B is the same as when the existing pile 4 is a hollow PC pile or PHC pile or a cast-in-place pile, but in the case of a steel pipe pile, the cutting depth is the PC pile or PHC. Since it is smaller than piles and cast-in-place piles, specific measures are required.

That is, in the case of steel pipe piles, the pipe wall thickness is smaller than in the case of PC piles or PHC piles, and the pile cutting work is completed at the stage where the depth of cut of the first bit 51 is small. There is almost no need to secure the cut space of the first bit 51 by the second bit 52 as in the case of a pile. Therefore, the second bit 52 is configured to be detachably attached to the rocking body 44 in advance, and as shown in FIG. 10, the second bit 52 is attached to the steel pipe pile when cutting the steel pipe pile. It is preferable that the steel pipe pile is cut by removing it from the rocking body 44 and using only the first bit 51. By doing so, on the cut pile 4B side, the cutting surface Pa approaches a plane substantially orthogonal to the axis of the steel pipe as much as possible, and unnecessary cutting parts are eliminated, so that the workability of the cutting work as a whole is improved. It will be improved.

G: Others (1) In the above embodiment, the cutting / removing device Z is provided with a pair of left and right cutting mechanisms 30, but the present invention is not limited to such a configuration, and for example, the cutting mechanism. It can be applied to the one provided with only one 30 and the one provided with three or more.

The existing pile cutting / removing device according to the present invention can be widely used for cutting / removing existing piles in civil engineering and construction work.

1 ・ ・ Casing 2 ・ ・ Swivel joint 3 ・ ・ Auger 4 ・ ・ Existing pile 5 ・ ・ Vertical bar 6 ・ ・ Horizontal bar 14 ・ ・ Tip excavation blade 15 ・ ・ Outer excavation blade 17 ・ ・ Spiral blade 18 ・ ・ Opening 19 ・・ Drive mechanism 20 ・ ・ Hydraulic cylinder 21 ・ ・ Rod 30 ・ ・ Cutting mechanism 32 ・ ・ Pit pin 33 ・ ・ Cam body 34 ・ ・ Guide case 41 ・ ・ Swing lever 42 ・ ・ Connecting pin 43 ・ ・ Pit shaft 44 ・ ・ Swinging body 51 ・ ・ 1st bit 52 ・ ・ 2nd bit 4A ・ ・ Remaining pile 4B ・ ・ Cutting pile Z ・ ・ Cutting and removing device

Claims (5)

An excavation blade and a cutting mechanism are provided at the lower end of a casing having an inner diameter larger than that of an existing pile and suspended and supported via an auger, and a drive mechanism for driving the cutting mechanism is provided at the upper end of the casing. It is a cutting and removing device for existing piles
The above cutting mechanism
A swinging body arranged inside the casing, in which a plate material having a predetermined width is formed into a substantially semicircular shape, and both ends in the circumferential direction are provided at coaxial positions in the chord direction of the casing. A rocking body that is pivotally supported by a shaft and is swing-driven by the drive mechanism in a direction that is brought into contact with and separated from the axis of the casing around the pivot shaft.
A first bit detachably attached to the edge of the rocking body near the axis of the casing in a state of extending forward in the swinging direction from the edge, and
An existing pile cutting / removing device including a second bit mounted on the inner surface of the rocking body in a state of extending in the width direction of the rocking body. In claim 1,
The rocking body has a non-operating position in which the first bit retracts toward the inner circumference of the casing and stands by at a gap between the inner peripheral surface and the outer peripheral surface of the existing pile, and the first bit. It swings forward and backward between the operating positions extending toward the center of the casing, and at the operating position, the rocking body and the first bit support the cut portion of the existing pile from below. An existing pile cutting and removing device, characterized in that it is configured to be capable. In claim 1 or 2,
An existing pile cutting / removing device characterized in that the second bit is detachably mounted on the inner surface of the rocking body. In claims 1, 2 or 3,
An existing pile cutting / removing device characterized in that a plurality of the cutting mechanisms are arranged in the circumferential direction of the casing. In claims 1, 2 or 3,
The drive mechanism includes a hydraulic cylinder arranged in the upper part of the casing, a cam body arranged in the vicinity of the cutting mechanism, and a rod for transmitting the operating force of the hydraulic cylinder to the cam body. An existing pile cutting and removing device characterized by this.

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