JPH0481003B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for removing foundation piles and other existing piles that are buried underground and are no longer needed, and an apparatus used for the removal.

(Prior Art) When rebuilding a building, it is necessary to remove existing piles such as foundation piles that are already buried underground.

If the existing pile was a relatively short pile made of wood, such as a pine pile, the top end of the pile was tied with a rope and pulled out, but the top end of the pile often broke off and the pile could not be pulled out. In such cases, the work of excavating around the pile and re-hanging the rope was repeated, which sometimes made it impossible to pull up the pile completely.

When the existing piles are concrete piles, there is no support for holding the existing piles, and the piles are heavy, making removal work difficult and dangerous. Therefore, in the past, when removing these existing piles, a casing such as a steel pipe with a larger diameter than the existing pile was buried underground so as to be concentric with the existing pile, and by pulling up this casing, the casing and the existing pile were removed. There are methods to pull up existing piles together with the casing by using the frictional resistance created by the earth and sand between them, and methods to reduce the frictional resistance when pulling up existing piles by adding water, bentonite, etc. to the casing and turning the inside of the casing into mud. There was a method that reduced the burden and only raised the existing piles.

(Problem to be solved by the invention) However, in the case of the former method, depending on the nature of the earth and sand in the casing, it may not be possible to support the weight of the existing pile and it may not be possible to pull up the existing pile. In addition, in the case of the latter method, water, etc. is required to turn the inside of the casing into mud, which increases the cost and lengthens the construction period, and also poses problems such as deterioration of the ground after water is injected. Summer. Furthermore, it was necessary to wrap the wire rope around the existing piles in a manner sufficient to pull them up against the viscosity of the muddy soil and the weight of the existing piles, but this work cannot necessarily be done reliably. The work involved danger.

(Means for Solving the Problems) The present invention has been made to solve the above-mentioned problems, and is to provide a removal casing that can be separated into upper and lower parts and has a retaining member for the existing pile inside. , press fit into the ground so as to surround the existing pile, then pull up the upper casing a little to separate it from the lower casing, rotate only the upper casing to form the holding member into a twisted holding body, and A removal method in which the existing pile is held by a holder and then pulled up together with the casing, and the removal casing that is driven surrounding the existing pile can be separated into upper and lower parts, and only the upper casing can be rotated. A retaining member for the existing pile is disposed on the inner wall of the upper casing, and one end of the retaining member is fixed to the inner wall of the lower casing that is separably disposed at the lower end of the upper casing. This is a device for removing existing piles.

(Operation) Press the casing into the ground to surround the existing piles to be removed. Next, when the casing is separated vertically and the upper casing is rotated, the holding members 3 such as ropes strung vertically between the upper casing and the lower casing engage with each other at the central axis, forming a radial net-like holding member. form the body. At this time, if the engaging portion of the upper casing and the lower casing is located below the lower end of the existing pile, the net-like holder supports the lower end of the existing pile from below, so that the existing pile is pulled up together with the casing.

(Example) In this specification, a twisted holding body is formed by twisting a holding member such as a rope, and includes a net-like holding body formed at the lower end of an existing pile and a holding body wound around the existing pile. There is.

An embodiment of the present invention will be described based on the drawings.

FIG. 1 is a partially cutaway sectional view of the lower end portion of an existing pile removal device according to a first embodiment of the present invention.

The removal device of this embodiment consists of a cylindrical casing for surrounding an existing pile, and a holding member 3 such as a rope constructed inside the casing.

The casing 2 is separable at its lower part,
An upper casing 21 and a lower casing 22 are configured. The upper casing 21 preferably has a length equal to or longer than the existing pile P.

An appropriate number of wire ropes R are disposed on the inner wall of the upper casing 21. Since this rope R is wound around the pile P to hold the pile P when the pile P is pulled up, not only a wire rope but also other ropes, chains, nets, etc. can be used.

The wire rope R is disposed along the inner wall surface of the upper casing 21 in the central axis direction, and its upper end is connected to the upper inner wall of the upper casing 21 or a lifting means (not shown) mounted on the upper end of the upper casing 21. ), and the lower end is locked through the locking part 51,
It is fixed to the inner wall of the lower casing 22.

The locking portion 51 constitutes a cylindrical body having an appropriate length on the lower inner wall surface of the upper casing 21, and the rope R is inserted into this cylindrical body. This locking portion 51 may have any structure within the scope of the present invention.

Furthermore, the upper casing 21 is provided with a rotational drive device M.
Concatenate. This rotary drive device M is connected to the casing 2
There are no particular limitations on the device as long as it has a driving force to rotate the device and a press-fitting power to propel or retreat underground.

The lower casing 22 is the upper casing 2
It has a cylindrical shape with the same diameter as 1, and its upper end is separably engaged with the upper casing 21.

The engaging portion 4 of the upper and lower casings 21 and 22 is a first
As shown in the figure, a triangular upper engagement portion 41 is provided that projects downward from the lower edge of the upper casing 21.
and a lower engaging portion 42 formed at a position opposite to the upper engaging portion 41 at the upper end edge of the lower casing 22 . Therefore, when the upper casing 21 rotates in the right direction in the drawing, both the engaging parts 41 and 42 engage and the rotational force is transmitted to the lower casing 22, but when the upper casing 21 rotates in the opposite direction or when it rises. When this happens, both casings 21 and 22 are disengaged.

There may be one set of engaging portions 4, or a large number of engaging portions 4, 4, . . . may be formed in a sawtooth shape.

The upper inner wall of the lower casing 22 has fixing parts 52, 5 for fixing the lower ends of the ropes R, R...
2... will be provided.

Further, in order to prevent the case where the net-like holder 6 is not completely formed due to the rotation of the lower casing 22 when the upper casing 21 rotates, a groove 55 or a protrusion is formed on the lower surface or side wall of the lower casing 22. Good too.

Next, the removal method of the present invention will be explained based on the operation of the above-mentioned removal device.

FIGS. 2a to 2e are explanatory diagrams showing the order of the method for removing existing piles. FIGS. 3a to 3d are cross-sectional views of the casing, illustrating the process of forming the net-like holder 6. FIGS. In FIG. 3, black circles indicate the fixing portion 52 of the wire rope R of the lower casing 22, and white circles indicate the position of the locking portion 51 of the upper casing 21.

Figure 2 (a) shows a cylindrical concrete pile buried underground. Normally, such an existing pile P is heavy, and it is difficult to hold the existing pile P when it is pulled out. There is no initiative to do so.

In order to pull out the existing pile P, first, the upper and lower casings 21 and 22 are connected together, and the casing 2 is press-fitted into the ground using a known rotary drive device M. At this time, the wire rope R inside the casing 2 is parallel to the traveling direction, so the resistance of the rope R during press-fitting does not pose a problem. (See Figures 2b and 3a) This press-fitting of the casing 2 is performed by inserting the upper casing 2
1 and the engaging portion 4 of the lower casing 22 reach a point slightly below the lower end of the existing pile P. (Second
(See Fig. 2(d)) Next, the upper casing 21 is pulled up a little to release the engagement between the upper casing 21 and the lower casing 22, and only the upper casing 21 is driven to rotate (see Fig. 2(d)). In this case, the lower casing 22 hardly rotates due to the frictional resistance between the sides and lower end and the surrounding earth and sand.

The rope R, which has one end fixed to the fixed part 52 of the lower casing 22 and is inserted through the engaging part 51 of the upper casing 21, passes through the center of the casing 2 as the upper casing 21 rotates. The upper casing 21 and the lower casing 22 are stretched diagonally to form a radial net-like holder 6. FIG. 3b shows this state, in which the net-like holder 6 is beginning to be stretched.

Thereafter, the upper casing 21 is further rotated to complete the net-like holder 6 and support the lower part of the existing pile P, so that the existing pile is pulled up together with the casing 2 (see FIG. 2e).

FIGS. 3c and 3d show a state in which the ropes R stretched vertically between the upper casing 21 and the lower casing 22 are engaged with each other at the center of the casing 2 to form a radial net-like holder 6. .

Although Figures 3a to 3c are explained using three ropes R in order to clarify the mutual action of the ropes R, in the actual site, the existing pile P is buried as shown in Figure 3d. Work is performed using multiple ropes R, R, etc. depending on the situation.

Rope R of the existing pile P pulled up in this way
By rotating the upper casing 21 in the opposite direction, the tightened state can be easily released, thereby speeding up the pile removal work.

A second embodiment is shown in FIG. In this embodiment, the casing 2a is configured to be shorter than the entire length of the pile P, and the engaging portion 51 at the lower end of the upper casing 21 configured in the first embodiment described above is omitted. The rest of the structure is the same as that of the embodiment.

When pulling out the pile P using this embodiment, the pile P
Drive the casing 2a halfway through, pull up the upper casing 21a a little and remove the lower casing 22a.
After that, only the upper casing 21a is rotated to wrap the rope R around the upper half of the pile P, and the casing 2a and the pile P are pulled out together. The apparatus and method of this embodiment are used for pulling out relatively short or light piles, and have the advantage of being simple in structure and method of use.

A third embodiment is shown in FIG. In this embodiment, the rope R is sequentially tightened from the bottom to the top of the existing pile P, and the rope R is tied to the upper casing 21.
The lower end is fixed to the fixing part 52 without passing through the locking part 51 at the lower end. The rest of the structure is the same as that of the first embodiment. Such a casing 2 is connected to the engaging portion 4 of the upper casing 21 and lower casing 22.
drive the rope R until it reaches a point slightly below the lower end of the existing pile P, pull up the upper casing 21 a little and separate it from the lower casing 22, and then rotate only the upper casing 21 to direct the rope R from below the existing pile P upward. Previously, the existing piles P
The outer periphery of is held tightly by a rope R over the entire circumference (see Fig. 5a). Finally, casing 2,
Rotate and pull up if necessary. At this time, the frictional resistance between the existing pile P and the twisted holding body increases, thereby preventing the existing pile P from falling off during pulling up. In this way, the existing pile P is reliably held and pulled up together with the casing 2, so that the removal work of the existing pile P can be carried out safely and reliably (see Fig. 5b).

(Effects of the Invention) As described above, the present invention removes existing piles using a simple removal device and removal method in which the casing is separated into upper and lower parts and a holding means for the existing piles is configured inside. It has the advantage of being superior in work efficiency, such as eliminating the need for attached equipment and shortening the construction period, as well as being superior in reliability and safety.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a partially cutaway sectional view of the lower part of the casing of the first embodiment;
Fig. 2 is an explanatory diagram showing the construction order of the pile removal method using the same device, Fig. 3 is an explanatory diagram illustrating the process of forming the net-like holder, and Fig. 4 is the device of the second embodiment and FIG. 5 is an explanatory diagram showing the order of implementation of the method for removing piles. FIG. 5 is an explanatory diagram showing the order of implementation of the apparatus and method of removing piles of the third embodiment. 2... Casing, 3... Holding member, 6... Net-like holding body.

Claims (1)

[Claims] 1. A removal casing that can be separated vertically and is equipped with a retaining member for the existing pile inside is press-fitted into the ground so as to surround the existing pile, and then the upper casing is pulled up a little. The holding member is separated from the lower casing and only the upper casing is rotated to form the above-mentioned holding member into a twisted holding body, and after the existing pile is held by the twisted holding body, the existing pile is pulled up together with the casing. How to remove existing piles. 2. The removal casing that is driven surrounding the existing pile is separable into upper and lower parts, and only the upper casing is formed to be rotatable, and a retaining member for the existing pile is provided on the inner wall of the upper casing, and A device for removing existing piles, characterized in that one end of the holding member is fixed to an inner wall of a lower casing that is separably disposed at the lower end of the upper casing.