JP6834041B1 - Pile pulling method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pile pulling grab and a pile pulling method capable of surely removing existing piles in the ground. SOLUTION: An upper end side is connected to a base 2 via a hinge 6 and the lower end side can swing, and by closing the lower end side, an existing pile P in the ground G can be grasped. , A pair of grab main bodies 3 each having a semi-cylindrical surface shape, and a grab drive mechanism 4 capable of giving different swing angles to each grab main body 3 of the pair of grab main bodies 3 when grasping the existing pile P. A pile-pulling grab 1 having a [Selection diagram] Fig. 1

Description

The present invention relates to a pile pulling grab and a pile pulling method for pulling out an existing pile in the ground.

At construction sites of buildings such as buildings and condominiums, piles are buried up to the hard ground, and the piles stably support the building. When the building is rebuilt, the existing piles (pile buried in the ground) that supported the building are also removed.

In the work of removing the existing pile, a method of freely dropping a hammer from above the existing pile and excavating by the impact force at that time (drop impact crushing method) may be adopted. However, this method is difficult to implement in urban areas where buildings such as houses are densely populated because of large vibration and noise.

For example, Patent Document 1 proposes a method for removing an existing pile, which is less likely to generate vibration or noise during work. In this method, first, the casing 50 to which the excavation bit is attached to the tip of the steel pipe is rotated by the all-around rotary excavator 150 to dig the ground 250 to a certain depth of the foundation pile 200. Next, the underground foundation pile dismantling device 100 is lowered to a predetermined position by the crane 10 inside the casing 50, and the stopper 105 of the underground foundation pile dismantling device 100 is projected toward the inner surface side of the casing 50.

In this state, when the casing 50 is rotated by the all-around rotary excavator 150, the arm 101 rotates around the foundation pile 200, and the tip blade 101a provided at the tip of the arm 101 comes into contact with the surface of the foundation pile 200. The foundation pile 200 is cut by the tip blade 101a. The cut piece 201 of the foundation pile 200 cut in this way is taken out by the arm 101 (see paragraphs 0017 to 0024 of Patent Document 1, FIGS. 4, 5 and the like).

Japanese Unexamined Patent Publication No. 2019-11551

An existing pile buried in the ground may have its axis eccentric from the axis of the casing or may be inclined from the vertical direction. In this case, according to the configuration shown in Patent Document 1, the tip blade 101a provided on the arm 101 that rotates coaxially with the casing 50 does not evenly contact the surface of the foundation pile 200. Therefore, the foundation pile 200 cannot be sufficiently cut, and the cut piece 201 may not be reliably removed.

Therefore, an object of the present invention is to reliably remove existing piles in the ground.

In order to solve the above problems, in the present invention, the base portion and the upper end side are connected to the base portion via a hinge so that the lower end side can swing, and the existing pile in the ground is closed by closing the lower end side. A pair of grab bodies each having a semi-cylindrical surface shape that can be grasped, and a grab drive that can give different swing angles to each grab body of the pair of grab bodies when grasping the existing pile. A mechanism and a grab for pulling piles having a mechanism were constructed.

In this way, since each of the pair of grab bodies has a different swing angle, the existing pile can be reliably grasped and pulled out regardless of the eccentric state or the inclined state of the existing pile in the ground.

In the above configuration, the pair of grab bodies taper toward the lower end, and by closing the lower end side of the pair of grab bodies, a receiving portion for scooping earth and sand is formed inside the lower end. be able to.

By forming the receiving portion at the lower ends of the pair of grab bodies in this way, the pair of grab bodies can be used as a tool for removing earth and sand from the inside of the housing. For this reason, it is not necessary to replace the tool when performing the process of pulling out the existing pile following the process of removing the earth and sand, and a series of operations can be smoothly performed.

In each of the above configurations, the grab drive mechanism includes a hydraulic cylinder provided corresponding to each of the pair of grab bodies, a link mechanism for connecting the hydraulic cylinder and the grab body corresponding thereto, and each of the above. The structure may include a hydraulic pipe connected to each of the hydraulic cylinders and a hydraulic device for supplying hydraulic oil of equal pressure to each of the hydraulic cylinders via the hydraulic pipe.

According to this configuration, when the existing pile is eccentric from the axial center of the casing or is inclined from the vertical direction, one of the grab main bodies first comes into contact with the existing pile by closing the lower ends of the pair of grab main bodies. Then, while the contact state of one grab body is maintained, the other grab body is further closed and abuts on the existing pile. At this time, since the hydraulic oil of the same pressure is supplied to each hydraulic cylinder from the hydraulic device, the contact force between the existing pile and each grab body is equal. Therefore, the existing pile can be stably gripped by the pair of grab bodies regardless of the eccentric state or the inclined state of the existing pile.

In each of the above configurations, an excavation blade for excavating the ground may be provided at the lower ends of the pair of grab bodies.

In this way, by rotating around the axis with the lower ends of the pair of grab bodies open, it is possible to smoothly dig to a predetermined depth in the ground.

Further, in the present invention, a cylindrical casing provided with a tip blade at the lower end and an inner peripheral blade at the inner circumference is rotated around an axis, and the ground is excavated by the tip blade to place the casing in the ground. A state in which a hollow portion is formed on the inner surface side of the casing while the earth and sand are removed by the inner peripheral blade, and the lower ends of the pair of grab bodies of the pile pulling grab according to each configuration are opened. In the insertion step of inserting the lower end into the cavity to a predetermined depth deeper than the upper end of the existing pile in the ground, and closing the lower ends of the pair of grab bodies to grab the existing pile in the ground and inserting the existing pile into the ground. A pile pulling method including a pulling step of pulling out from the pile was constructed.

In this way, by inserting the pair of grab bodies into the cavities formed in advance by the casing, the pile pulling grabs can be installed at predetermined positions, so that a series of pile pulling operations can proceed smoothly. Can be done.

Further, in the present invention, the first excavation step of rotating a cylindrical casing provided with a tip blade at the lower end around an axis, excavating the ground with the tip blade and embedding the casing in the ground, and the above-mentioned The pair of grab bodies for pulling piles according to each configuration are rotated around the axis with the lower ends open, and the pair of grab bodies bring the ground to a predetermined depth deeper than the upper ends of the existing piles in the ground. A pile pulling method including a second excavation step of excavating and a pulling step of closing the lower ends of the pair of grab bodies to grab an existing pile in the ground and pulling out the existing pile from the ground was configured.

In this way, after digging the ground by rotating the pair of grab bodies, it is possible to move to the existing pile pulling process without exchanging tools, so that a series of pile pulling operations can proceed smoothly. ..

As described above, the present invention has made it possible to give different swing angles to each of the pair of grab bodies of the pile pulling grab, so that the existing pile is irrespective of the eccentric state or the inclined state of the existing pile. Can be surely grasped. Further, in the pile pulling method using this pile pulling grab, the pair of grab bodies are reached to a predetermined depth at which the existing pile can be grasped by inserting into the cavity or rotating excavating the pile pulling grab. A series of pulling out of existing piles can be carried out smoothly.

Front view showing a reference example of a grab for pulling piles Top view of the pile pulling grab shown in FIG. Front view showing a state in which an existing pile (coaxial state) is grasped by the pile pulling grab shown in FIG. Front view showing a state in which an existing pile (eccentric state) is grasped by the pile pulling grab shown in FIG. It is sectional drawing which shows the reference example of the process of the pile pulling method, (a) is the state which lowered while rotating the casing, (b) is the state which the casing is embedded in a predetermined depth, (c) is a pile. The state where the earth and sand are removed using the pulling grab, (d) is the state where the pair of grab bodies of the pile pulling grab are inserted into the cavity, and (e) is the state where the pair of grab bodies are closed and the existing pile is grasped. , (F) shows the state where the existing pile is pulled out. It is sectional drawing which shows an example of the process of the pile pulling method which concerns on this invention, (a) is the state which lowered while rotating the casing, (b) is the state which the casing is embedded in a predetermined depth, (c ) Is a state in which earth and sand are removed using a pile-pulling grab, (d) is a state in which a pair of grab bodies of the pile-pulling grab are rotated and inserted to a predetermined depth, and (e) is a state in which the pair of grab bodies are closed. The state where the existing pile is grasped, (f) is the state where the existing pile is pulled out.

A reference example of the pile pulling grab 1 will be described with reference to the drawings. As shown in FIGS. 1 and 2, the pile pulling grab 1 includes a base 2, a pair of grab main bodies 3, and a grab drive mechanism 4 as main components.

The base 2 is a member that serves as a mounting base for mounting each component of the pile pulling grab 1. An auger (not shown) that rotates the pull-out wire 5 (see FIG. 5 (e)) or the base 2 (pile pulling grab 1) around the axis can be connected to the upper side of the base portion 2. ..

Each of the grab main bodies 3 has a semi-cylindrical surface shape and is a pair of members having an inverted triangular shape when viewed from the front. The upper end side thereof is connected to the base portion 2 via a hinge 6 and the lower end side is swingable. The pair of grab bodies 3 taper toward the bottom. By closing the lower end side of the pair of grab bodies 3, the existing pile P in the ground G can be grasped. Further, by completely closing the lower ends of the pair of grab main bodies 3, a receiving portion for scooping earth and sand is formed inside the lower ends. In addition, in order to securely grip the existing pile P, a protrusion or the like for slip prevention may be formed on the inner surface side of the grab main body 3.

The grab drive mechanism 4 includes a hydraulic cylinder 7, a link mechanism 8, a hydraulic pipe 9, and a hydraulic device 10, and when gripping the existing pile P, each grab body 3 and the existing grab body 3 of the pair of grab bodies 3 are installed. It is possible to give different swing angles according to the contact state with the pile P. In FIG. 2, the description of the hydraulic pipe 9 and the hydraulic device 10 is omitted.

The hydraulic cylinder 7 is fixed to the base 2 so as to correspond to each position of the pair of grab main bodies 3. The hydraulic cylinder 7 has a rod 11 that appears and disappears due to the hydraulic pressure of the hydraulic oil. The link mechanism 8 connects the rod 11 of the hydraulic cylinder 7 and the grab body 3 corresponding to the hydraulic cylinder 7. The lower end side of the hydraulic pipe 9 is bifurcated, and the branched end is divided into and connected to each hydraulic cylinder 7. The hydraulic device 10 is connected to the upper end side of the hydraulic pipe 9, and supplies hydraulic oil of equal pressure to each hydraulic cylinder 7 via the hydraulic pipe 9.

As shown in FIG. 3, the hydraulic pipe from the hydraulic device 10 is in a state where the existing pile P is located exactly in the middle of the pair of grab main bodies 3 (that is, in a state coaxial with the casing 12 (see FIG. 5E)). When hydraulic oil is supplied to each hydraulic cylinder 7 via 9, the rod 11 protrudes from the hydraulic cylinder 7, and the link mechanism 8 is pushed downward by the rod 11. Then, due to the downward force acting on the link mechanism 8, each grab body 3 connected to the link mechanism 8 swings around the axis of the hinge 6. At this time, since the hydraulic oil of the same pressure acts on each hydraulic cylinder 7 from the common hydraulic device 10, the swing angles of the grab main bodies 3 become equal, and the existing piles P are formed by the pair of grab main bodies 3. Can be reliably grasped from the left and right.

On the other hand, as shown in FIG. 4, the existing pile P is eccentric from the pair of grab main bodies 3 (that is, eccentric from the casing 12) from the hydraulic device 10 to each hydraulic cylinder 7 via the hydraulic pipe 9. When the hydraulic oil is supplied, the rod 11 protrudes from the hydraulic cylinder 7, and the link mechanism 8 is pushed downward by the rod 11. When the existing pile P is eccentric, first, the grab body 3 (hereinafter referred to as the grab body 3a on one side) on the side closer to the existing pile P (left side in the example shown in FIG. 4) comes into contact with the existing pile P. .. At this time, the grab body 3 (hereinafter referred to as the other grab body 3b) on the side far from the existing pile P (on the right side in the example shown in FIG. 4) has not yet come into contact with the existing pile P (in FIG. 4). Refer to the grab body 3b indicated by the alternate long and short dash line.

Here, when the hydraulic oil is further supplied from the hydraulic device 10, the grab body 3a on one side keeps in contact with the existing pile P, and the grab body 3b on the other side further swings, and the other side. The grab body 3b on the side also comes into contact with the existing pile P. At this time, both grab bodies 3a and 3b have different swing angles. FIG. 4 shows the case where the existing pile P is in the eccentric state, but similarly to this, the existing pile P can be reliably grasped by the pair of grab main bodies 3.

Reference examples of the steps of the pile pulling method are shown in FIGS. 5A to 5F. This pile pulling method has an excavation step, an insertion step, and a pulling step as main components. In this figure, the description of the hydraulic pipe 9 and the hydraulic device 10 is omitted.

In the excavation process, a cylindrical casing 12 having a tip blade 13 at the lower end and an inner peripheral blade 14 at the inner circumference is used (see FIG. 5A). The casing 12 is embedded in the ground G by rotating the casing 12 around an axis using an auger (not shown) and excavating the ground G with the tip blade 13. The embedding depth of the casing 12 needs to be at least a depth at which the lower end of the casing 12 is lower than the upper end of the existing pile P, and preferably the depth at which the existing pile P is surrounded by the casing 12 over its entire length. ..

In this excavation process, a hollow portion 15 from which earth and sand have been removed by the inner peripheral blade 14 is formed on the inner surface side of the casing 12 (see FIG. 5B). Further, after the casing 12 is embedded, the earth and sand are on the upper side of the existing pile P. This earth and sand is removed by using the pile pulling grab 1 described above (see FIG. 5C).

In the insertion step, the pile pulling grab 1 described above is used. The upper end side of the pile pulling grab 1 is suspended by a pulling wire 5 wound by a take-up device (not shown) (see FIG. 5 (e)). A hollow portion formed on the inner surface side of the casing 12 so that the lower ends of the pair of grab bodies 3 of the pile pulling grab 1 are opened and the lower ends are deeper than the upper ends of the existing piles P in the ground G. Insert into 15 (see FIG. 5 (d)).

In the pulling step, after closing the lower ends of the pair of grab main bodies 3 and grasping the existing pile P in the ground G (see FIG. 5E), the pile pulling grab 1 is pulled upward by the pulling wire 5. The existing pile P is pulled out from the ground G (see FIG. 5 (f)). The timing for gripping the existing pile P with the pair of grab main bodies 3 can be appropriately determined, but by setting the timing at which the upper end of the existing pile P comes into contact with the lower surface of the base 2 of the pile pulling grab 1, the pair of grabs The existing pile P can be reliably grasped by the main body 3. After the existing pile P is pulled out, the casing 12 is pulled out and the holes are backfilled.

According to the pile pulling method according to this reference example , since it is sufficient to insert the pair of grab main bodies 3 into the cavity portion 15 formed in advance by the casing 12, the insertion work is very simple and the work cost is reduced. be able to.

An example of the process of the pile pulling method according to the present invention is shown in FIGS. 6 (a) to 6 (f). This pile pulling method has a first excavation process, a second excavation process, and a drawing process as main components. In this figure, the description of the hydraulic pipe 9 and the hydraulic device 10 is omitted.

In the first excavation step, a cylindrical casing 12 provided with a tip blade 13 at the lower end is used (see FIG. 6A). The casing 12 is embedded in the ground G by rotating the casing 12 around an axis using an auger (not shown) and excavating the ground G with the tip blade 13 (see FIG. 6B). The embedding depth of the casing 12 needs to be at least a depth at which the lower end of the casing 12 is lower than the upper end of the existing pile P, and preferably the depth at which the existing pile P is surrounded by the casing 12 over its entire length. .. Further, after the casing 12 is embedded, the earth and sand are on the upper side of the existing pile P. This earth and sand is removed by using the pile pulling grab 1 described above (see FIG. 6 (c)).

In the second excavation step, the pile pulling grab 1 described above is used. An excavation blade 16 (hard tip) for excavating the ground G is provided at the lower end of the pair of grab main bodies 3 of the pile removal grab 1. Instead of providing the excavation blade 16, the lower end of the club body 3 may be subjected to a hardening treatment such as heat treatment. The upper end of the pile pulling grab 1 is connected to an auger (not shown).

With the lower ends of the pair of grab bodies 3 open, the pile pulling grab 1 is rotated around the axis by the auger, and the ground G is dug with the pair of grab bodies 3. By rotating the grab main body 3 in this way, the existing pile P and the grab main body 3 are likely to be in a coaxial state, and in the subsequent drawing step, the existing pile P can be easily grasped by the pair of grab main bodies 3. The depth of digging by the grab body 3 needs to be at least a depth at which the lower end of the grab body 3 is lower than the upper end of the existing pile P in the ground G, and preferably the upper end of the existing pile P is the pile removal grab. The depth is set to abut on the lower surface of the base 2 of No. 1 (see FIG. 6 (d)).

In the pulling process, the lower ends of the pair of grab bodies 3 are closed to grasp the existing pile P in the ground G (see FIG. 6E), and then the pile pulling grab 1 together with the auger is pulled upward. The existing pile P is pulled out from the ground G (see FIG. 6 (f)). The timing for gripping the existing pile P with the pair of grab main bodies 3 can be appropriately determined, but by setting the timing at which the upper end of the existing pile P comes into contact with the lower surface of the base 2 of the pile pulling grab 1, the pair of grabs The existing pile P can be reliably grasped by the main body 3. After the existing pile P is pulled out, the casing 12 is pulled out and the holes are backfilled.

According to the pile pulling method according to this example , after digging the ground G by rotating the pair of grab main bodies 3, it is possible to move to the pulling process of the existing pile P without exchanging tools, so that a series of pile pulling can be performed. Work can proceed smoothly.

The pile pulling method shown in FIGS. 5 (a) to 5 (f) and FIGS. 6 (a) to 6 (f) has been described by exemplifying the case where the existing pile P is coaxial with the casing 12, but the existing pile P has been described. Can be eccentric or inclined with respect to the casing 12, and the pile removal operation can be performed in the same process.

The pile-pulling grab 1 and the pile-pulling method described above are merely examples, and are for pile-pulling as long as the problem of the present invention of reliably removing the existing pile P in the ground G can be solved. Part of the structure of the grab 1 and the process of the pile pulling method can be changed as appropriate.

For example, in the above embodiment, the hydraulic cylinder 7 is provided corresponding to each grab main body 3, and the hydraulic oil of isobaric pressure is supplied from the hydraulic device 10 common to each hydraulic cylinder 7. There is a possibility that the hydraulic devices 10 are individually provided on the 7 to control the swing of each grab body 3 independently.

1 Pile pulling grab 2 Base 3 Grab body 4 Grab drive mechanism 5 Pulling wire 6 Hinge
7 Hydraulic cylinder 8 Link mechanism 9 Hydraulic pipe 10 Hydraulic device 11 Rod 12 Casing 13 Tip blade 14 Inner peripheral blade 15 Cavity 16 Excavation blade P Existing pile G Ground

Claims (1)

A cylindrical casing (12) provided with a tip blade (13) at the lower end is rotated around an axis, the ground (G) is excavated by the tip blade (13), and the casing (12) is ground (G). ) The first excavation process to be embedded in
The upper end side is connected to the base portion (2) and the base portion (2) via a hinge (6) so that the lower end side can swing. By closing the lower end side, an existing pile (P) in the ground (G) ), A pair of grab bodies (3) each having a semi-cylindrical surface shape, and each grab body (3) of the pair of grab bodies (3) when gripping the existing pile (P). ) Has a grab drive mechanism (4) capable of giving different swing angles, and the pair of grab bodies (3) taper toward the lower end, and the pair of grab bodies (3) are tapered toward the lower end. By completely closing the lower end side of the semi-cylindrical surface so that the end faces of the semi-cylindrical surface face each other, a receiving portion for scooping earth and sand is formed inside the lower end surface, and the grab drive mechanism (4) forms the pair of grab bodies ( A hydraulic cylinder (7) provided corresponding to each of the 3), a link mechanism (8) for connecting the hydraulic cylinder (7) and the grab body (3) corresponding thereto, and each hydraulic cylinder (3). It has a hydraulic pipe (9) connected to each of the 7) and a hydraulic device (10) for supplying hydraulic oil to each hydraulic cylinder (7) via the hydraulic pipe (9). In (9), the lower end side thereof is bifurcated, the branched end portion is divided into the respective hydraulic cylinders (7) and connected, and the hydraulic device (10) is connected to the upper end side of the hydraulic pipe (9). are connected, the semi-cylindrical surfaces of the pair of glove body (3) of the hydraulic tube (9) pile vent glove supplies hydraulic oil isobaric to the each hydraulic cylinder (7) via (1) A removal step in which the end faces of the cylinders are completely closed so as to face each other, and the earth and sand on the upper side of the existing pile (P) is scooped and removed by a receiving portion formed inside the lower end thereof.
A predetermined depth deeper than the upper end of the existing pile (P) in the ground (G) by the pair of grab bodies (3) by rotating the pair of grab bodies (3) around the axis with the lower ends open. The second excavation process to excavate the ground (G) and
A pull-out step of closing the lower ends of the pair of grab bodies (3), grasping the existing pile (P) in the ground (G), and pulling out the existing pile (P) from the ground (G).
Pile pulling method with.

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