JP2012241329A - Method of removing existing pile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of removing an existing pile, in which waste earth is easily treated and work efficiency is excellent.SOLUTION: The method of removing an existing pile comprises a second excavation step of excavating the periphery of an existing pile 3 in order to edge-cutting the outer periphery of the existing pile 3 from the ground by jetting water to the ground excavated by a drill 12, turning waste earth generated by excavation into slurry and discharging it while agitating it with a blade 11, while rotating second and first casings 2 and 1 by imparting torque to the second casing 2. By advancing excavation without jetting water and without discharging the waste earth excavated by the drill 12 upwards and filling the waste earth between a distal end of the first casing 1 and a distal end of the existing pile 3, the existing pile 3 is fixed to the first casing 1.

Description

  The present invention relates to a method for removing an existing pile.

  When demolishing a building to make it clear, it is necessary to remove existing piles that have been driven into the ground that forms the foundation of the building. Therefore, conventionally, there has been proposed a method of removing a concrete pile containing a reinforcing bar used for the pile. (See Patent Document 1)

Japanese Patent Publication No.6-29519 (Fig. 4) U3, 156, 209 (Fig. 3)

  However, according to the method of Patent Document 1, it is difficult to process the soil removal, which may make it difficult to excavate.

  On the other hand, Patent Document 2 proposes a construction method in which excavation buckets and cutting buckets are alternately used, and excavation and cutting are alternately performed. However, in this conventional construction method, it takes much time to replace the two types of buckets, and the working efficiency is lowered.

  Accordingly, an object of the present invention is to provide a method for removing an existing pile that is easy to process soil removal and has excellent work efficiency.

In order to achieve the above-mentioned purpose, it is a construction method for removing an existing pile driven into the ground,
First and second casings 1 provided with blades 11 projecting radially inwardly on the inner peripheral surface of the cylindrical body 10 having an inner diameter larger than the outer diameter of the pile and stirring the discharged soil, and a pipe 42 for supplying water. , 2 and a drill 12 provided at the lower end of the lowermost first casing 1 for excavation, the first casing 1 provided with the drill 12 is given a rotational force to rotate the first casing 1. While spraying water from the tip of the pipe 42 to the ground excavated by the drill 12, the soil generated by the excavation is muddy and discharged upward while stirring with the blade plate 11. A first digging step of digging around the existing pile 3 in order to cut off the outer periphery of the existing pile 3 from the ground, the rotational force transmitted from the casing to the casing, and the pipe 42 The connecting step of connecting the casings in the axial direction so that the two are connected to each other, and applying the rotational force to the second casing 2, while rotating the second and first casings 2, 1, Water is sprayed from the tip of the pipe 42 to the ground excavated by the drill 12 without spraying water, and the soil generated by the excavation is made muddy and discharged upward while stirring with the blade plate 11. Then, in order to cut the outer periphery of the existing pile 3 from the ground, a second digging step of digging around the existing pile 3 and applying a rotational force to the second casing 2, the second and first While rotating the casings 2 and 1, the excavated soil excavated by the drill 12 without jetting the water is excavated without discharging upward, and the tip portion of the first casing 1 The third part which fixes the existing pile 3 in the first casing 1 while cutting the outer periphery of the existing pile 3 from the ground by packing the soil between the tip portions of the existing pile 3. After the excavation step and the third excavation step, the second and first casings 2 and 1 are lifted, and the existing pile 3 that has been edge-cut from the ground over the entire length of the existing pile 3 by the excavation is And a lifting step of lifting to the ground together with the second casings 1 and 2.

In the case of the present invention, the casings 1 and 2 are connected one after another for excavation, so that there is no need to replace the casings 1 and 2.
Moreover, by discharging water and adding bentonite, the discharged soil becomes muddy water and easily rises.
Further, since the muddy water is agitated by the blades 11 formed in the casings 1 and 2 and sent upward, there is no possibility that excavation will be hindered by the soil removal.

It is a side view which shows the 1st excavation process concerning one Example of this invention. It is a longitudinal cross-sectional view of each casing. It is a side view which shows a 2nd excavation process. It is a side view which shows each process. It is a side view which shows each process. It is a side view which shows a 3rd excavation process.

  In a preferred embodiment of the present invention, the existing water is generated by the water pressure generated between the lower end surface 30 of the existing pile 3 and the ground by discharging pressure water from the tip of the pipe 42 toward the lower side of the existing pile 3. The lifting step is performed while pushing the lower end surface 30 of the pile 3 upward.

  In this case, since the water pressure is applied to the lower end surface 30 of the existing pile 3, it becomes easy to lift the existing pile 3 together with the casings 1 and 2.

Hereinafter, an embodiment of a boring device 5 according to the present invention will be described with reference to the drawings.
overall structure:
As shown in FIG. 1, the boring device 5 for pushing into the ground S while rotating the casing includes a band 51, a rotating mechanism 52, and a casing jack 53.

Casing 1, 2:
As shown in FIGS. 1 to 3, the casings 1 and 2 are formed in a cylindrical shape, and a drill 12 is provided at the tip of the first casing 1. When the casings 1 and 2 shown in FIG. 3 rotate and dig into the ground S, the excavated soil enters between the pipe-like casings 1 and 2 and the existing pile 3.
In addition, in FIG. 3, the pile 3 is shown with the virtual line so that the inside of the casings 1 and 2 can be seen.

  Each of the casings 1 and 2 is provided with one or a plurality of blade plates 11 on the inner peripheral surface of the cylindrical body 10 which are useful for stirring and discharging water-soiled soil upward. Each casing 1, 2 is provided with a hole 57 for transmitting the rotational force of the rotation mechanism 52. The soil is discharged from the hole 57 or the opening at the upper end of the casing.

A small-diameter fitting portion 13 is provided at the upper end portion of the first casing 1 and the upper end portion of the second casing 2 of FIG. 2, while the fitting portion 13 is provided at the lower end portion of each second casing 2. The fitting part 14 which fits in is provided. By fitting the fitting portion 14 to the fitting portion 13 and fastening them with bolts, the casings 1 and 2 can be added one after another. When the upper portions of the casings 1 and 2 reach a predetermined position as shown in FIG. 4C, the second casing 2 for extension indicated by a two-dot chain line in FIG. Boring is performed deeply in the ground by adding the second casing 2 one after another.

As shown in FIG. 1, the casing jack 53 is installed on the ground surface and holds a rotating mechanism 52.
The casing jack 53 includes a frame 54 installed on the ground surface, and a jack portion 55 fixed to the frame 54. The jack portion 55 is provided with an elevating portion 56 that is moved up and down by the jack portion 55.
The detailed structure of the boring device 5 is disclosed in paragraphs 0013 to 0023 of U3,135,204.

During excavation, a water guide device 4 shown in FIG. 1A is installed at the upper end of the uppermost casing. A swivel-type joint 40 provided at the axial center of the upper end of the first casing 1 or the second casing 2, a first water conduit (pipe) 41 for guiding water outward from the joint 40 in the radial direction, and The water is injected to the ground to be excavated through a second water conduit (pipe) 42 extending downward.
In addition, each pipe 42 is mutually joined for each casing 1,2.
The joint 40 is supplied with water pumped by a water pressure or a water pressure pump.

Below, the removal method of the existing pile 3 is demonstrated. First, as shown to FIG. 4A, the boring apparatus 5 is installed in the ground surface above the existing pile 3 which should be removed. Next, as shown in FIG. 1B, the first casing 1 is held by the boring device 5. At this time, the water guiding device 4 is installed above the first casing 1.

In FIG. 4B and FIG. 1B, while rotating the first casing 1 by applying a rotational force to the first casing 1 by the boring device 5, water is injected into the ground excavated by the drill 12 and the excavation occurs. The muddy drainage is agitated with the slats 11 (FIG. 2) and swirled upwards to dig around the existing pile 3 in order to cut the outer periphery of the existing pile 3 from the ground. Execute the excavation process.
Along with the injection of water, bentonite is preferably added between the casing 1 (2) and the pile 3. Thereby, the muddy drained soil is easily lifted upward.

When the position of the upper end of the first casing 1 reaches a predetermined height, the water guiding device 4 is removed from the first casing 1. Thereafter, as shown in FIG. 4C, the lower end of the second casing 2 is connected to the upper end of the first casing 1.
That is, the connecting step of connecting the casings to each other in the axial direction is performed so that the rotational force is transmitted from the casing to the casing and the pipes 42 adjacent to each other in FIG. At this time, the first casing 1 and the second casing 2 are positioned in the circumferential direction so that the pipes 42 are connected to each other, and the pipes 42 are connected.

Thereafter, as shown in FIG. 4D, water is sprayed onto the ground excavated by the drill 12 while rotating the second and first casings 2 and 1 by applying a rotational force to the second casing 2. In addition, the mud drained soil generated by the excavation is swirled upward while stirring with the slat 11 (FIG. 2), so that the outer periphery of the existing pile 3 can be cut off from the ground. A second excavation process is performed to dig around.

Thereafter, by repeating the connection step and the second excavation step, the existing pile 3 is cut from the ground over substantially the entire length of the existing pile 3 with the tip portion remaining.

A third excavation step is performed immediately before the existing pile 3 is completely cut off from the ground.
That is, as shown in FIG. 6, in the third digging step, the water is injected while rotating the second and first casings 2, 1 by applying a rotational force to the second casing 2. The excavated soil excavated by the drill 12 without digging up without digging upward and filling the excavated soil S1 between the distal end portion of the first casing 1 and the distal end portion of the existing pile 3, While cutting the outer periphery of the existing pile 3 from the ground, the existing pile 3 is fixed in the first casing 1. A plug S <b> 1 is formed at the tip of the first casing 1 and the existing pile 3 by the soil removal.

In the state where the plug S1 is formed, pressure water is discharged from the tip of the pipe 42 toward the lower side of the existing pile 3, and the existing pressure is generated by water pressure generated between the lower end surface 30 of the existing pile 3 and the ground. The following lifting process is performed while pushing the lower end surface 30 of the pile 3.

That is, in FIG. 5A, after the third excavation step, the second and first casings 2 and 1 are lifted, and the existing pile 3 is removed from the ground by the excavation over the entire length of the existing pile 3. And it lifts on the ground like FIG.

After the lifting step, as shown in FIG. 5C, the uppermost second casing 2 is removed to expose the existing pile 3. Thereafter, as shown in FIG. 5C, the wire W is hung on the upper portion of the existing pile 3 and the existing pile 3 is held by the boring device 5. Thus, in the state where the upper end portion of the exposed existing pile 3 is held and suspended, and the casing under the removed second casing 2 is held, the existing pile is placed between the held portions. The upper part of 3 is cut and removed at the site indicated by arrow C. Thereafter, the existing pile 3 is again suspended by the wire W as shown in FIG. 5D, and the steps of holding and removing are repeated to cut and remove the existing pile 3.

This invention can be used for the construction method which removes an existing pile.

1: First casing 2: Second casing 10: Cylindrical body 11: Blades
12: Drill 13: Fitting part 14: Fitting part 3: Existing pile 30: Lower end surface 4: Water guide device 40: Joint 41: First water conduit (pipe)
42: Second water conduit (pipe)
5: Boring device 51: Band 52: Rotating mechanism 53: Casing jack 54: Frame 55: Jack part 56: Lifting part 57: Hole S1: Plug

Claims (3)

A method of removing existing piles that have been driven into the ground,
First and second casings 1 provided with blades 11 projecting radially inwardly on the inner peripheral surface of the cylindrical body 10 having an inner diameter larger than the outer diameter of the pile and stirring the discharged soil, and a pipe 42 for supplying water. , 2 and a drill 12 provided at the lower end of the lowermost first casing 1 for excavation,
While rotating the first casing 1 by applying a rotational force to the first casing 1 provided with the drill 12, water is injected from the tip of the pipe 42 to the ground excavated by the drill 12, and the excavation is performed. A first excavation step of digging around the existing pile 3 in order to cut the outer periphery of the existing pile 3 from the ground by turning the generated soil into muddy water and discharging it upward while stirring with the blades 11; ,
A connecting step of connecting the casings in the axial direction so that the rotational force is transmitted from the casing to the casing and the pipes 42 are connected to each other;
By applying a rotational force to the second casing 2, the tip of the pipe 42 is ground on the ground excavated by the drill 12 without spraying the water while rotating the second and first casings 2, 1. In order to cut off the outer periphery of the existing pile 3 from the ground, the existing pile 3 is discharged by discharging water from the ground and discharging the soil generated by the excavation upward while stirring with the blades 11. A second digging process that digs around,
By applying rotational force to the second casing 2, the soil excavated by the drill 12 is discharged upward without spraying the water while rotating the second and first casings 2, 1. The outer periphery of the existing pile 3 is cut off from the ground by filling the drainage between the tip portion of the first casing 1 and the tip portion of the existing pile 3, and the first casing 1. A third digging step for fixing the existing pile 3 in
After the third excavation step, the second and first casings 2 and 1 are lifted, and the existing pile 3 cut from the ground over the entire length of the existing pile 3 by the excavation is used as the first and second casings 1. , 2 and a lifting step of lifting to the ground. In the construction method according to claim 1, pressure water is discharged from the tip of the pipe 42 toward the lower side of the existing pile 3, and the pressure of the existing pile 3 is generated by water pressure generated between the lower end surface 30 of the existing pile 3 and the ground. The lifting step is performed while pushing the lower end surface 30 upward. In the construction method according to claim 2, after the lifting step, the step of removing the uppermost second casing 2 and exposing the existing pile 3;
In the state where the upper end portion of the exposed existing pile 3 is held and suspended, and the casing below the removed second casing 2 is held, the existing pile is placed between the two held portions. The process of cutting and removing the upper part of 3 is repeated to cut and remove the existing pile 3.

Images