Method and system for removing existing piles
The method addresses the need for large machinery and ground loosening by embedding a casing and using a crane with a clamping device to extract piles, ensuring efficient and minimal ground disturbance.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- MAEDA CORP
- Filing Date
- 2025-04-01
- Publication Date
- 2026-07-21
AI Technical Summary
Conventional methods for removing existing piles require large construction machinery and risk ground loosening during extraction.
A method involving embedding a cylindrical casing around the pile, using a crane to lift the pile while maintaining the casing in the ground, and employing a pile clamping device to extract the pile, with optional water injection to reduce friction.
The method allows for efficient pile extraction with minimal ground disturbance using a simple device configuration.
Smart Images
Figure 2026120068000001_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to a method for removing existing piles embedded in the ground and an existing pile removal system.
Background Art
[0002] When demolishing an existing structure and constructing a new structure, it is necessary to remove existing piles, which are foundation piles supporting the existing structure and remain in the ground after demolishing the existing structure.
[0003] As a method for removing existing piles, sometimes after excavating the periphery of an existing pile from the ground using a casing, the casing and the existing pile are integrated and pulled up to the ground. After pulling up the casing and the existing pile to the ground, the existing pile is crushed and removed while only the casing is lifted.
Prior Art Documents
Patent Documents
[0004] [[ID=2,6]]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0005] In the conventional method for removing existing piles, the construction machinery used for removing existing piles had to be large or a dedicated machine. In addition, there was a risk of causing loosening of the ground when pulling out existing piles from the ground.
[0006] In the invention described in Patent Document 1, it is disclosed that a casing is arranged so as to surround the outer periphery of an existing pile in which a core drilling is performed to be a bottomed cylindrical shape, and by the buoyancy generated by injecting a liquid inside the casing, it becomes easier to pull out the existing pile to the ground. In this invention, since a dedicated device for performing core drilling to be a bottomed cylindrical shape with respect to the existing pile is required, it is not preferable.
[0007] In view of the circumstances described above, at least one embodiment of this disclosure aims to provide a method and system for removing existing piles that can extract existing piles from the ground with a simple device configuration and that can suppress the loosening of the ground when the existing piles are extracted from the ground. [Means for solving the problem]
[0008] A method for removing existing piles according to at least one embodiment of this disclosure is: A method for removing existing piles embedded in the ground, A casing embedding step involves embedding a cylindrical casing into the ground so as to surround the outer circumference of the existing pile, The system includes, after the casing embedding step, a pile extraction step in which the existing pile is pulled out of the ground by a crane while maintaining the state in which the casing is embedded in the ground, In the aforementioned pile extraction step, The pile clamping device, which is configured to clamp the upper end of the existing pile with a portion inserted inside the casing, is used to clamp the upper end of the existing pile, and the pile clamping device is then lifted by the crane.
[0009] The existing pile removal system according to at least one embodiment of the present disclosure is A system for removing existing piles embedded in the ground, A crane having a lifting section, wherein the lifting section is configured to be vertically movable, A cylindrical casing is configured to surround the outer circumference of the aforementioned existing pile, The system includes a pile clamping device that is suspended from the lifting section and configured to clamp the upper end of the existing pile with a portion of it inserted inside the casing. [Effects of the Invention]
[0010] According to at least one embodiment of this disclosure, a method and system for removing existing piles are provided that can extract existing piles from the ground with a simple device configuration and suppress the loosening of the ground when the existing piles are extracted from the ground. [Brief explanation of the drawing]
[0011] [Figure 1] This is an explanatory diagram illustrating an example of a flow chart for a method of removing existing piles according to one embodiment of the present disclosure. [Figure 2] This is an explanatory diagram illustrating the casing embedding step in one embodiment of the present disclosure. [Figure 3] This is an explanatory diagram illustrating the casing embedding step in one embodiment of the present disclosure. [Figure 4] This is an explanatory diagram illustrating the casing embedding step in one embodiment of the present disclosure. [Figure 5] This is an explanatory diagram illustrating the casing embedding step in one embodiment of the present disclosure. [Figure 6] This is a schematic diagram showing the lower end of the casing as viewed from the radially outer side in one embodiment of the present disclosure. [Figure 7] This is a schematic cross-sectional view along the axial direction of the casing and water inlet channel forming member in one embodiment of the present disclosure. [Figure 8] This is a schematic cross-sectional view showing a cross-section perpendicular to the axial direction of the casing and water inlet channel forming member in one embodiment of the present disclosure. [Figure 9] This is an explanatory diagram illustrating the pile extraction step in one embodiment of the present disclosure. [Figure 10] This is an explanatory diagram illustrating the pile extraction step in one embodiment of the present disclosure. [Figure 11] This is a schematic diagram of a pile clamping device in one embodiment of the present disclosure. [Figure 12] This is a schematic diagram of a pile clamping device in one embodiment of the present disclosure. [Figure 13]It is a schematic view seen from one axial side of the pile clamping device in one embodiment of the present disclosure. [Figure 14] It is a schematic view seen from one axial side of the pile clamping device in one embodiment of the present disclosure. [Figure 15] It is an explanatory diagram for explaining the pile pulling-out step in one embodiment of the present disclosure. [Figure 16] It is an explanatory diagram for explaining the pulling-out of an existing pile when the existing pile breaks during the pile pulling-out step in one embodiment of the present disclosure. [Figure 17] It is an explanatory diagram for explaining the pulling-out of an existing pile when the existing pile breaks during the pile pulling-out step in one embodiment of the present disclosure. [Figure 18] It is an explanatory diagram for explaining the backfilling step in one embodiment of the present disclosure. [Figure 19] It is an explanatory diagram for explaining the backfilling step in one embodiment of the present disclosure. [Figure 20] It is an explanatory diagram for explaining the backfilling step in one embodiment of the present disclosure. [Figure 21] It is an explanatory diagram for explaining the casing pulling-out step in one embodiment of the present disclosure. [Figure 22] It is an explanatory diagram for explaining the casing pulling-out step in one embodiment of the present disclosure.
Mode for Carrying Out the Invention
[0012] Hereinafter, some embodiments of the present disclosure will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described as embodiments or shown in the drawings are not intended to limit the scope of the present disclosure thereto, but are merely illustrative examples.
[0013] (Method for Removing Existing Piles) Figure 1 is an explanatory diagram illustrating an example of a flow chart of a method for removing existing piles 2 according to one embodiment of this disclosure. The methods for removing existing piles 2 according to several embodiments are methods for removing existing piles 2 embedded in the ground. Existing piles 2 are, for example, foundation piles that support structures, and are foundation piles that remain in the ground after the structure has been demolished. Since existing piles 2 become underground obstacles when the land is reused, it is necessary to pull out the existing piles 2 and backfill the land after the existing piles 2 have been pulled out.
[0014] The method for removing existing piles 2, as shown in Figure 1, comprises at least a casing embedding step S1 and a pile extraction step S2. In the embodiment shown in Figure 1, the method for removing existing piles 2 further comprises a backfilling step S3 and a casing extraction step S4. In the method for removing existing piles 2 according to the following embodiment, an existing pile removal system 1 is used. The existing pile removal system 1, as shown in Figure 2, comprises a casing 3, a crane 4, and a casing embedding device 5.
[0015] (Casing embedding step) Figures 2 to 5 are explanatory diagrams illustrating the casing embedding step S1 in one embodiment of the present disclosure. In the casing embedding step S1, a cylindrical casing 3 is embedded so as to surround the outer circumference of the existing pile 2.
[0016] Generally, existing piles 2 are embedded below the ground (reference plane) 10 on which the crane 4 is placed, as shown in Figure 2. In some embodiments of the method for removing existing piles 2, before the casing embedding step S1, the area around the ground in which the existing piles 2 are embedded is excavated using an excavation device such as a hydraulic excavator to expose the upper end (pile head) 21 of the existing piles 2. In one embodiment, when exposing the upper end of the existing piles 2, the area around the ground in which the existing piles 2 are embedded is excavated by the excavation device to a range of less than 1 m below the end face (upper end) 210 of the upper end 21 of the existing piles 2.
[0017] (crane) As shown in Figure 2, a crane 4 is used in the casing embedding step S1. The crane 4 has a lifting section 41 and is configured to be able to move up and down by power supplied from a power source (not shown) (e.g., hydraulics). In the illustrated embodiment, the crane 4 is a mobile crane (crane truck) and is configured to be able to transport the suspended load horizontally.
[0018] In the illustrated embodiment, the crane 4 comprises a lifting section 41, a crane body section 42 configured to be able to travel on the ground, and a boom 43 with one end connected to the crane body section 42 and the other end connected to the lifting section 41.
[0019] The boom 43 is configured to be luffable, that is, to allow the angle of inclination of the boom 43 relative to the crane body 42 to be changed. Furthermore, the boom 43 is configured to be extendable, that is, to allow the length between one end connected to the crane body 42 and the other end connected to the lifting section 41 to be changed. The crane 4 moves the lifting section 41 up and down by luffing and extending the boom 43. The crane 4 may also be configured to allow the boom 43 to rotate around a pivot axis extending vertically.
[0020] In the casing embedding step S1, as shown in Figure 2, a cylindrical casing 3 is attached to the lifting section 41 of the crane 4 via a casing embedding device 5. The casing 3 is a cylindrical body extending along its axial direction and has an outer circumferential surface 31 and an inner circumferential surface 32. The inner diameter D2 of the casing 3 is larger than the outer diameter D1 of the existing pile 2. In one embodiment, the outer diameter D1 of the existing pile 2 is 300 mm or more and 600 mm or less.
[0021] The casing embedding device (e.g., auger) 5 has a main body 51 that is suspended from a lifting section 41, as shown in Figure 2. The casing embedding device 5 has a casing support section 52 configured to detachably support the upper end 33, which is one axial end of the casing 3. The casing embedding device 5 has a rotational drive mechanism 53 for rotating the casing support section 52 along the circumferential direction, and is configured to rotate the casing 3 along the circumferential direction by driving the rotational drive mechanism 53 with power supplied from a power source (not shown) (e.g., hydraulics).
[0022] The casing embedding step S1 includes a casing excavation step S11 in which the lower end 34, which is the other axial end of the casing 3, excavates the ground around the existing pile 2. In the casing excavation step S11, as shown in Figure 3, the casing 3, which has been rotated by the casing embedding device 5, is lowered downward together with the casing embedding device 5 by the crane 4, thereby excavating the ground around the existing pile 2 with the lower end 34 of the casing 3. As a result of this casing excavation step S11, as shown in Figure 4, the cylindrical casing 3 is embedded in the ground so as to surround the outer circumference of the existing pile 2. By separating the existing pile 2 from the ground with the casing 3 embedded in the ground, the frictional force of the ground on the existing pile 2 can be reduced, making it easier to pull the existing pile 2 out of the ground.
[0023] In some embodiments of the method for removing existing piles 2, as shown in Figure 4, the casing 3 described above is longer than the existing pile 2. In other words, the axial length of the casing 3 is greater than the axial length of the existing pile 2. In the casing embedding step S1, the lower end 340, which is the end face of the lower end 34 of the casing 3, is embedded deeper in the ground than the lower end 220, which is the end face of the lower end 22 of the existing pile 2.
[0024] In the method for removing existing piles 2 according to this embodiment, the lower end 340 of the casing 3 is buried deeper in the ground than the lower end 220 of the existing pile 2. This allows for a more effective separation of the existing pile 2 from the ground by the casing 3 compared to the case where the casing 3 is buried shallower than the lower end 220 of the existing pile 2.
[0025] In some embodiments of the method for removing existing piles 2, as shown in Figure 2, when the outer diameter of the existing pile 2 is D1, the inner diameter D2 of the casing 3 satisfies the condition 1.2D1 ≤ D2 ≤ 1.5D1.
[0026] In the method for removing existing piles 2 according to this embodiment, the inner diameter D2 of the casing 3 is set to satisfy the condition 1.2D1 ≤ D2 ≤ 1.5D1, thereby effectively isolating the existing piles 2 from the ground by the casing 3 embedded in the ground. As a result, in the method for removing existing piles 2 according to this embodiment, the frictional force of the ground on the existing piles 2 can be effectively reduced, making it easier to pull the existing piles 2 out of the ground.
[0027] If the inner diameter D2 of casing 3 is set to less than 1.2D1, the difference between the outer diameter D1 of the existing pile 2 and the inner diameter D2 of casing 3 will be small, which may make it difficult to embed casing 3 around the existing pile 2 or to extract the existing pile 2 that is housed inside casing 3. Conversely, if the inner diameter D2 of casing 3 is set to more than 1.5D1, the difference between the outer diameter D1 of the existing pile 2 and the inner diameter D2 of casing 3 will be large, which may weaken the effect of the embedded casing 3 in separating the existing pile 2 from the ground.
[0028] In the method for removing the existing pile 2 according to this embodiment, as shown in Figure 5, after the casing 3 is embedded in the ground so as to surround the outer circumference of the existing pile 2, the casing embedding device 5 is removed from the upper end 33 of the casing 3.
[0029] (Drilling blade) Figure 6 is a schematic view of the lower end portion 34 of the casing 3 as seen from the radially outer side in one embodiment of the present disclosure. As shown in Figure 6, drilling blades 35 may be attached to the lower end portion 34 of the casing 3 such that the end face (lower end) 340 of the lower end portion 34 is uneven. In the illustrated embodiment, a plurality of drilling blades 35 are arranged at intervals in the circumferential direction of the casing 3 and fixed to the casing 3. Note that the plurality of drilling blades 35 may be integrally formed with the lower end portion 34 of the casing 3.
[0030] (protrusion) As shown in Figure 6, the outer circumferential surface 31A(31) of the lower end portion 34 of the casing 3 may be provided with a projection 36 for guiding the soil excavated by the lower end portion 34 of the casing 3 upward. The projection 36 is provided protruding from the outer circumferential surface 31 of the lower end portion 34 and is inclined with respect to the circumferential direction of the casing 3. That is, one end of the projection 36 in the longitudinal direction is provided at a position offset in the axial direction of the casing 3 compared to the other end. In the illustrated embodiment, a plurality of projections 36 are arranged at intervals in the circumferential direction of the casing 3. In the illustrated embodiment, when the plurality of projections 36 arranged at intervals in the circumferential direction of the casing 3 are considered as one stage, the plurality of projections 36 are arranged in multiple stages at intervals in the axial direction of the casing 3.
[0031] (Water injection step) The casing embedding step S1 preferably further includes a watering step S12, which is performed during the execution of the casing excavation step S11, as shown in Figure 1. In the watering step S12, water is injected around the lower end 34 of the casing 3 by a watering device 6. The existing pile removal system 1 may also include a watering device 6.
[0032] Figure 7 is a schematic cross-sectional view along the axial direction of the casing 3 and the water inlet channel forming member 61 in one embodiment of the present disclosure. Figure 8 is a schematic cross-sectional view showing a cross-section perpendicular to the axial direction of the casing 3 and the water inlet channel forming member 61 in one embodiment of the present disclosure. The water inlet device 6 includes at least one (multiple in the illustrated example) water inlet channel forming member 61 supported by the casing 3, as shown in Figures 7 and 8. Each of the multiple water inlet channel forming member 61 extends along the axial direction of the casing 3 and has an opening 62 for discharging water at one end in the direction of extension of the water inlet channel forming member 61.
[0033] Each of the multiple water inlet channel forming members 61 forms a channel for guiding water supplied from the outside to the opening 62. In the embodiments shown in Figures 7 and 8, each of the multiple water inlet channel forming members 61 has an inner surface 611 that forms a water inlet channel between itself and the outer circumferential surface 31 of the casing 3. In the illustrated embodiments, each of the multiple water inlet channel forming members 61 has a U-shaped cross-section in a cross-sectional view perpendicular to the axial direction of the casing 3, and is configured to form a water inlet channel between itself and the casing 3. In the illustrated embodiments, the water inlet channels formed by each of the multiple water inlet channel forming members 61 have a channel cross-section that has a longitudinal direction along the direction perpendicular to the radial direction of the casing 3 (tangential direction of the outer circumferential surface 31) in a cross-sectional view perpendicular to the axial direction of the casing 3.
[0034] When the casing 3 is supported by the casing embedding device 5, the axial direction of the casing 3 extends along the vertical direction. At this time, the opening 62 of the water injection channel forming member 61 is directed downward, so that the injected water is discharged downward.
[0035] The opening 62 is provided near the lower end 34 of the casing 3. In some embodiments, when the axial position of the end face (upper end) 330 of the upper end 33 of the casing 3 is set to 0% and the axial position of the end face (lower end) 340 of the lower end 34 of the casing 3 is set to 100%, the opening 62 of the water inlet channel forming member 61 is provided at an axial position of 90% to 110%, preferably 95% to 105%.
[0036] In the embodiments shown in Figures 7 and 8, each of the multiple water inlet channel forming members 61 is fixed to the outer circumferential surface 31 of the casing 3, but it may also be fixed to the inner circumferential surface 32 of the casing 3. Each of the multiple water inlet channel forming members 61 is arranged at intervals from each other in the circumferential direction of the casing 3.
[0037] The water injection device 6 is configured to receive water from a water source (not shown), such as a pump, to the water injection channel forming member 61. The water supplied to the water injection channel forming member 61 is discharged to the outside of the water injection channel forming member 61 through the opening 62. In the water injection step S12, the water discharged downward from the opening 62 of the water injection channel forming member 61 increases the moisture content of the ground around the lower end 34 of the casing 3, reducing the frictional resistance of the ground around the lower end 34 of the casing 3 to the lower end 34 of the casing 3, thereby making the excavation of the ground around the existing pile 2 by the lower end 34 of the casing 3 more effective.
[0038] In the method for removing existing piles 2 according to this embodiment, the water injection step S12 is performed while the casing excavation step S11 is being executed, thereby increasing the water content of the ground on the outer periphery side of the casing 3 and reducing the frictional resistance of the ground on the outer periphery side of the casing 3 to the casing 3, which makes it easier to pull out the casing 3 from the ground as described later.
[0039] In the method for removing the existing pile 2 according to this embodiment, the water injection step S12 is performed while the casing excavation step S11 is being executed. This increases the moisture content of the ground on the inner circumference side of the casing 3, that is, the ground between the casing 3 and the existing pile 2. As a result, buoyancy acts on the existing pile 2 due to the moisture contained in the ground between the casing 3 and the existing pile 2, making it easier to pull the existing pile 2 out of the ground.
[0040] (Pile extraction step) Figures 9 and 10 are explanatory diagrams illustrating the pile extraction step S2 in one embodiment of the present disclosure. The pile extraction step S2 is performed after the casing embedding step S1. In the pile extraction step S2, the existing pile 2 is extracted from the ground by a crane 4 while maintaining the state in which the casing 3 is embedded in the ground.
[0041] In the pile extraction step S2, as shown in Figures 9 and 10, the upper end 21 of the existing pile 2 is clamped by a pile clamping device 7, which is configured to clamp the upper end 21 of the existing pile 2 with a portion inserted inside the casing 3, and the pile clamping device 7 is lifted by a crane 4. The existing pile removal system 1 includes a pile clamping device 7 as shown in Figures 9 and 10.
[0042] (Pile clamping device) Figures 11 and 12 are schematic diagrams of a pile clamping device 7 in one embodiment of the present disclosure. Figures 13 and 14 are schematic diagrams of a pile clamping device 7 in one embodiment of the present disclosure viewed from one side in the axial direction. As shown in Figures 11 to 14, the pile clamping device 7 includes a main body 71, a rotating part 72, and a plurality of clamping parts 73.
[0043] The main body 71 of the pile clamping device 7 is configured to be suspended and supported by the crane 4. The pile clamping device 7 includes a plurality of clamping parts 73 and the same number of rotating parts 72. Each of the plurality of rotating parts 72 is a rotation mechanism for rotating the clamping part 73 corresponding to the rotating part 72 relative to the main body 71 about the rotation axis 72A of the rotating part 72. In the illustrated embodiment, as shown in Figures 13 and 14, each of the plurality of rotating parts 72 has a rotation axis 72A that extends in a direction perpendicular to the radial direction of the pile clamping device 7 in a plane perpendicular to the axial direction of the pile clamping device 7, and is arranged at a distance from other rotating parts 72 in the circumferential direction of the pile clamping device 7.
[0044] In the embodiments shown in Figures 9 to 13, the pile clamping device 7 includes two clamping portions 73 that are opposite to each other in a plane along a direction perpendicular to the axial direction of the pile clamping device 7. As shown in Figure 14, the pile clamping device 7 may include three or more (three in the illustrated example) clamping portions 73 that are spaced apart in the circumferential direction of the pile clamping device 7 in a plane along a direction perpendicular to the axial direction of the pile clamping device 7.
[0045] Each of the multiple clamping portions 73 is formed in an arc shape having an outer surface 731 and an inner surface 732, and is rotatably supported relative to the main body 71 via a rotating portion 72 connected to a protruding portion 733 that protrudes from the inner surface 732. Each of the multiple clamping portions 73 is arranged such that the inner surface 732 faces radially inward of the pile clamping device 7, and the protruding portion 733 protrudes radially inward of the pile clamping device 7.
[0046] Each of the multiple clamping portions 73 is rotated relative to the main body portion 71 via a rotating portion 72 by power supplied from a power source (not shown) (for example, hydraulics), thereby allowing it to be closed radially inward of the pile clamping device 7 or opened radially outward of the pile clamping device 7. By closing the multiple clamping portions 73, the upper end portion 21 of the existing pile 2 can be clamped by the multiple clamping portions 73. Conversely, by opening the multiple clamping portions 73, the clamping of the upper end portion 21 of the existing pile 2 by the multiple clamping portions 73 can be released.
[0047] In the illustrated embodiment, each of the multiple clamping portions 73 is configured to perform the opening and closing operation described above by power transmitted via a wire 75 connected to the rotating portion 72 in a power-transmitting manner. Each of the multiple clamping portions 73 is configured to close when the wire 75 is wound up by a device capable of winding up and down the wire 75, such as a wire winding device 414, and to open when the wire 75 is wound down and the upward force is eliminated.
[0048] In the pile extraction step S2, the upper end 21 of the existing pile 2 is clamped by multiple clamping parts 73. By clamping the upper end 21 of the existing pile 2 by multiple clamping parts 73 and lifting the existing pile 2 together with the pile clamping device 7 using the crane 4, the existing pile 2 can be extracted from the ground.
[0049] In the embodiments shown in Figures 9 and 10, the lifting section 41 of the crane 4 includes a first lifting section 411 for suspending and supporting the casing embedding device 5, and a second lifting section 412 for suspending and supporting the pile clamping device 7. The casing embedding device 5 is suspended and supported by the first lifting section 411, and the pile clamping device 7 is suspended and supported by the second lifting section 412.
[0050] The second lifting section 412 is suspended and supported from the tip of the boom 43 via a wire 413 that hangs vertically from the tip of the boom 43 (the other end). The second lifting section 412 can change its vertical distance from the tip of the boom 43 (the other end) by winding up or down the wire 413 using a wire winding device 414 which includes a pulley around which the wire 413 is wound.
[0051] In the embodiments shown in Figures 9 and 10, the second lifting section 412, the pile clamping device 7, and the existing pile 2 are raised upward by extending the length of the boom 43. However, the second lifting section 412, the pile clamping device 7, and the existing pile 2 may also be raised upward by winding up the wire 413 with the wire winding device 414.
[0052] A method for removing an existing pile 2 according to several embodiments comprises the casing embedding step S1 described above and the pile extraction step S2 described above. A system 1 for removing an existing pile 2 according to several embodiments comprises at least a casing 3, a crane 4, a casing embedding device 5, and a pile clamping device 7.
[0053] In the existing pile removal method and existing pile removal system 1 according to this embodiment, the existing pile 2 is pulled out of the ground by the crane 4 and pile clamping device 7 while maintaining the state in which the casing 3 is embedded in the ground, thereby suppressing the loosening of the ground when the existing pile 2 is pulled out of the ground. Furthermore, in the existing pile removal method and existing pile removal system 1 according to this embodiment, the existing pile 2 can be pulled out of the ground by the crane 4 and pile clamping device 7, which each have a simple device configuration.
[0054] Furthermore, in the existing pile removal method and existing pile removal system 1 according to this embodiment, the upper end portion 21 of the existing pile 2 can be gripped by a pile gripping device 7 which includes a main body portion 71, a rotating portion 72, and a plurality of gripping portions 73. In this case, the existing pile 2 can be pulled out of the ground by a crane 4 and a pile gripping device 7, each of which have a simple device configuration.
[0055] In some embodiments, as shown in Figures 12 to 14, multiple protrusions 74 are formed on the inner surface 732 of the multiple clamping portions 73 described above, spaced apart along the axial direction of the pile clamping device 7, with the inner surface 732 protruding from the inner surface 732. In the embodiments shown in Figures 12 to 14, when the multiple protrusions 74 formed spaced apart along the axial direction of the pile clamping device 7 are considered as one row of protrusions, two rows of protrusions are formed at positions separated from each other in the circumferential direction of the pile clamping device 7.
[0056] In the method for removing existing piles 2 and the system for removing existing piles 2 according to this embodiment, the upper end portion 21 of the existing piles 2 can be more securely gripped by the multiple protrusions 74 formed on the inner surface 732 of the multiple clamping portions 73.
[0057] Figure 15 is an explanatory diagram illustrating the pile extraction step S2 in one embodiment of the present disclosure. In the pile extraction step S2 described above, if the crane 4 and the pile clamping device 7 cannot extract the entire existing pile 2 from the ground, the wire 11 may be wrapped around the portion of the existing pile 2 that is exposed above ground. The wire 11 is supported by the second lifting unit 412 and lifted by the crane 4, thereby pulling the existing pile 2 upwards. By changing the axial position of the existing pile 2 around which the wire 11 is wrapped, the entire existing pile 2 can be extracted from the ground.
[0058] In the existing pile removal method and existing pile removal system 1 according to this embodiment, even if the length of the boom 43 of the crane 4 is relatively small, the entire existing pile 2 can be pulled out from the ground, thus allowing the use of a relatively small crane 4.
[0059] Figures 16 and 17 are explanatory diagrams illustrating the extraction of the existing pile 2 when it fractures during the pile extraction step S2 in one embodiment of the present disclosure. As shown in Figure 16, when the existing pile 2 is lifted by the crane 4 and the pile clamping device 7, or before the existing pile 2 is lifted, the existing pile 2 may fracture so as to be divided into multiple pieces in the axial direction of the existing pile 2.
[0060] In the embodiment shown in Figure 16, the existing pile 2 is divided into an upper existing pile 2A, which includes the upper end portion 21 of the existing pile 2, and a lower existing pile 2B, which includes the lower end portion 22 of the existing pile 2. In the pile extraction step S2, as shown in Figures 16 and 17, the divided existing piles 2 (upper existing pile 2A, lower existing pile 2B) are lifted from inside the casing 3 in order from the uppermost one by the crane 4 and the pile clamping device 7. In this case, the maximum length of the pile clamping device 7 in the direction perpendicular to the axial direction must be smaller than the inner diameter of the casing 3 so that the pile clamping device 7 can move up and down inside the casing 3.
[0061] (Backfill step) Figures 18 to 20 are explanatory diagrams illustrating the backfilling step S3 in one embodiment of the present disclosure. The backfilling step S3 is performed after the pile extraction step S2. In the backfilling step S3, as shown in Figures 18 to 20, the inside of the casing 3 is filled with a filling material 12 such as soil. As shown in Figure 20, it is preferable that the filling material 12 is filled inside the casing 3 to a height of approximately the ground (reference plane) 10.
[0062] As shown in Figure 19, the weight 13 supported by the second lifting section 412 may be lowered onto the filling 12 inside the casing 3 by the crane 4, and the filling 12 inside the casing 3 may be compacted by the weight of the weight 13 and the impact when the weight 13 is lowered onto the filling 12. Whether or not it is necessary to compact the filling 12 inside the casing 3 depends on the material of the filling 12. For example, if the filling 12 inside the casing 3 is mainly composed of soil, which has a relatively high effect of density increase due to compaction, it is often preferable to compact the filling 12 inside the casing 3. Also, if the filling 12 inside the casing 3 is mainly composed of crushed stone or sand, which has a relatively low effect of density increase due to compaction, it is often unnecessary to compact the filling 12 inside the casing 3. If it is not necessary to compact the filling 12 inside the casing 3, the step of lowering the weight 13 supported by the second lifting section 412 onto the filling 12 inside the casing 3 by the crane 4 is not necessary. The method for removing existing piles 2 described herein allows for the use of various materials as the filling material 12, depending on site conditions, compared to the conventional method of backfilling the area after pulling out the casing 3.
[0063] (Casing removal step) Figures 21 and 22 are explanatory diagrams illustrating the casing extraction step S4 in one embodiment of the present disclosure. The casing extraction step S4 is performed after the pile extraction step S2 and the backfilling step S3. In the casing extraction step S4, the casing 3 is extracted from the ground by a crane 4.
[0064] In the illustrated embodiment, during the casing extraction step S4, as shown in Figure 21, the cylindrical casing 3 is attached to the lifting section 41 of the crane 4 via the casing embedding device 5. The upper end portion 33 of the casing 3 is supported by the casing support section 52 of the casing embedding device 5.
[0065] In the illustrated embodiment, in the casing extraction step S4, as shown in Figure 22, the casing 3, whose upper end portion 33 is supported by the casing embedding device 5, is lifted upward together with the casing embedding device 5 by the crane 4, thereby extracting the casing 3 from the ground.
[0066] Furthermore, in each step S1, S2, and S4 of the method for removing the existing pile 2, the same crane 4 may be used, or different cranes 4 may be used. The first lifting section 411 and the second lifting section 412 may be provided on different cranes 4.
[0067] In this specification, expressions describing relative or absolute arrangements such as "in a certain direction," "along a certain direction," "parallel," "orthogonal," "center," "concentric," or "coaxial" shall not only describe such arrangements strictly, but also describe states of relative displacement with tolerances or angles or distances that allow for the same function to be achieved. For example, expressions such as "identical," "equal," and "homogeneous" that describe things being in an equal state not only describe a state of being strictly equal, but also describe a state in which there is a tolerance or a difference that is sufficient to achieve the same function. Furthermore, in this specification, expressions describing shapes such as quadrilaterals and cylindrical shapes shall not only represent geometrically precise quadrilaterals and cylindrical shapes, but also shapes that include uneven surfaces, chamfered surfaces, etc., to the extent that the same effect can be achieved. Furthermore, in this specification, the expressions “equipment,” “includes,” or “possess” of a component are not exclusive expressions that exclude the existence of other components.
[0068] This disclosure is not limited to the embodiments described above, but also includes modified forms of the embodiments described above, as well as forms that combine these forms as appropriate.
[0069] The contents described in some of the embodiments above can be understood, for example, as follows:
[0070] [1] A method for removing an existing pile (2) according to at least one embodiment of the present disclosure is: A method for removing existing piles (2) embedded in the ground, A casing embedding step (S1) involves embedding a cylindrical casing (3) into the ground so as to surround the outer circumference of the existing pile (2), The system includes, after the casing embedding step (S1), a pile extraction step (S2) in which the existing pile (2) is pulled out of the ground by a crane (4) while maintaining the state in which the casing (3) is embedded in the ground, In the aforementioned pile extraction step (S2), The pile clamping device (7), which is configured to clamp the upper end (21) of the existing pile (2) with a portion of it inserted inside the casing (3), is made to clamp the upper end (21) of the existing pile (2), and the pile clamping device (7) is then lifted by the crane (4).
[0071] According to the method described in [1] above, in the method for removing existing piles (2), the loosening of the ground when the existing piles (2) are pulled out of the ground is suppressed by using a crane (4) and a pile clamping device (7) while maintaining the state in which the casing (3) is embedded in the ground. Furthermore, in the method for removing existing piles (2) according to this embodiment, the existing piles (2) can be pulled out of the ground using a crane (4) and a pile clamping device (7), each of which has a simple device configuration.
[0072] [2] In some embodiments, the method for removing the existing pile (2) described in [1] above, The aforementioned pile clamping device (7) is The main body (71) is configured to be suspended and supported by the crane (4), The main body (71) is supported via a rotating part (72) so as to be movable along the radial direction, and includes a plurality of clamping parts (73) that are spaced apart in the circumferential direction, In the aforementioned pile extraction step (S2), The upper end portion (21) of the existing pile (2) is clamped by the plurality of clamping portions (73).
[0073] According to the method described in [2] above, the existing pile (2) can be removed by a pile clamping device (7) which includes a main body (71), a rotating part (72), and a plurality of clamping parts (73), to clamp the upper end (21) of the existing pile (2). In this case, the existing pile (2) can be pulled out of the ground by a crane (4) and a pile clamping device (7), each of which has a simple device configuration.
[0074] [3] In some embodiments, the method for removing the existing pile (2) described in [2] above, Multiple protrusions (74) are formed on the inner surface (732) of the multiple clamping portions (73) at intervals along the axial direction of the pile clamping device (7), with the protrusions (74) extending from the inner surface (732).
[0075] According to the method described in [3] above, the method for removing the existing pile (2) allows for more secure clamping of the upper end portion (21) of the existing pile (2) by the multiple protrusions (74) formed on the inner surface (732) of the multiple clamping portions (73).
[0076] [4] In some embodiments, the method for removing an existing pile (2) as described in any of [1] to [3] above, In the casing embedding step (S1), The water is injected around the lower end portion (34) of the casing (3) via at least one water injection channel forming member (61) which is supported by the casing (3) and has an opening (62) for releasing the injected water downward.
[0077] According to the method described in [4] above, in the method for removing the existing pile (2), water is injected from the opening (62) of the water injection channel forming member (61) to increase the water content of the ground around the lower end (34) of the casing (3), thereby reducing the frictional resistance of the ground around the lower end (34) of the casing (3) to the lower end (34) of the casing (3), and thus the excavation of the ground around the existing pile (2) by the lower end (34) of the casing (3) is performed more effectively.
[0078] Furthermore, according to the method described in [4] above, in the method for removing the existing pile (2), water is injected from the opening (62) of the water injection channel forming member (61) to increase the moisture content of the ground around the lower end (34) of the casing (3), thereby reducing the frictional resistance of the ground around the lower end (34) of the casing (3) to the lower end (34) of the casing (3), and thus making it easier to pull the casing (3) out of the ground.
[0079] Furthermore, according to the method described in [4] above, in the method for removing the existing pile (2), by injecting water from the opening (62) of the water injection channel forming member (61), the moisture content of the ground on the inner circumference side of the casing (3), that is, the ground between the casing (3) and the existing pile (2), is increased, and the moisture contained in the ground between the casing (3) and the existing pile (2) causes buoyancy to act on the existing pile (2), making it easier to pull the existing pile (2) out of the ground.
[0080] [5] In some embodiments, the method for removing an existing pile (2) as described in any of [1] to [4] above, The casing (3) is longer than the existing pile (2), In the casing embedding step (S1), the lower end (340) of the casing (3) is buried deeper in the ground than the lower end (220) of the existing pile (2).
[0081] According to the method described in [5] above, in the method for removing the existing pile (2), the lower end (340) of the casing (3) is buried deeper in the ground than the lower end (220) of the existing pile (2), thereby more effectively isolating the existing pile (2) from the ground by the casing (3) compared to the case where it is buried shallower than the lower end (220) of the existing pile (2).
[0082] [6] In some embodiments, the method for removing an existing pile (2) described in any of [1] to [5] above, When the outer diameter of the existing pile (2) is D1, the inner diameter D2 of the casing (3) satisfies the condition 1.2D1 ≤ D2 ≤ 1.5D1.
[0083] According to the method described in [6] above, in the method for removing the existing pile (2), the inner diameter D2 of the casing (3) is set to satisfy the condition 1.2D1 ≤ D2 ≤ 1.5D1, thereby effectively isolating the existing pile (2) from the ground by the casing (3) embedded in the ground. As a result, in the method for removing the existing pile (2) according to this embodiment, the frictional force of the ground on the existing pile (2) can be effectively reduced, and the existing pile (2) can be easily pulled out from the ground.
[0084] [7] An existing pile (2) removal system (1) according to at least one embodiment of the present disclosure is A system (1) for removing existing piles (2) embedded in the ground, A crane (4) having a lifting section (41) and configured so that the lifting section (41) can move up and down, A cylindrical casing (3) is configured to surround the outer circumference of the existing pile (2), The system includes a pile clamping device (7) which is suspended from the lifting section (41) and configured to clamp the upper end (21) of the existing pile (2) with a portion of it inserted inside the casing (3).
[0085] According to the configuration described in [7] above, the existing pile (2) removal system (1) can suppress the loosening of the ground when the existing pile (2) is pulled out of the ground by a crane (4) and a pile clamping device (7) while maintaining the state in which the casing (3) is embedded in the ground. Furthermore, the existing pile (2) removal system (1) according to this embodiment can pull out the existing pile (2) from the ground by a crane (4) and a pile clamping device (7), each of which has a simple device configuration.
[0086] [8] In some embodiments, the existing pile (2) removal system (1) described in [7] above, The aforementioned pile clamping device (7) is The main body (71) is configured to be suspended and supported by the crane (4), The device includes a plurality of clamping portions (73) which are supported on the main body portion (71) via a rotating portion (72) so as to be movable along the radial direction, and which are spaced apart in the circumferential direction, and which are configured to clamp the upper end portion (21) of the existing pile (2).
[0087] According to the configuration described in [8] above, the existing pile removal system (1) can grip the upper end (21) of the existing pile (2) with a pile clamping device (7) which includes a main body (71), a rotating part (72), and a plurality of clamping parts (73). In this case, the existing pile (2) can be pulled out of the ground by a crane (4) and a pile clamping device (7), each of which has a simple device configuration.
[0088] [9] In some embodiments, the existing pile (2) removal system (1) described in [8] above, Multiple protrusions (74) are formed on the inner surface (732) of the multiple clamping portions (73) at intervals along the axial direction of the pile clamping device (7), with the protrusions (74) extending from the inner surface (732).
[0089] According to the configuration described in [9] above, the existing pile removal system (1) can more reliably grip the upper end (21) of the existing pile (2) with the multiple protrusions (74) formed on the inner surface (732) of the multiple clamping parts (73).
[0090]
[10] In some embodiments, the existing pile removal system (1) described in any of [7] to [9] above, The casing (3) is further provided with a water injection device (6) for injecting water around the lower end (34), The water injection device (6) includes at least one water injection channel forming member (61) that is supported by the casing (3) and has an opening (62) for releasing the water downward.
[0091] According to the configuration described in
[10] above, the existing pile (2) removal system (1) increases the moisture content of the ground around the lower end (34) of the casing (3) by injecting water from the opening (62) of the water injection channel forming member (61), thereby reducing the frictional resistance of the ground around the lower end (34) of the casing (3) to the lower end (34) of the casing (3), and thus the excavation of the ground around the existing pile (2) by the lower end (34) of the casing (3) is performed more effectively.
[0092] Furthermore, according to the configuration described in
[10] above, the existing pile removal system (1) increases the moisture content of the ground around the lower end (34) of the casing (3) by injecting water from the opening (62) of the water injection channel forming member (61), thereby reducing the frictional resistance of the ground around the lower end (34) of the casing (3) to the lower end (34) of the casing (3), and making it easier to pull the casing (3) out of the ground.
[0093] Furthermore, according to the configuration described in
[10] above, the existing pile (2) removal system (1) increases the moisture content of the ground on the inner circumference side of the casing (3), that is, the ground between the casing (3) and the existing pile (2), by injecting water from the opening (62) of the water injection channel forming member (61). As a result, buoyancy acts on the existing pile (2) due to the moisture contained in the ground between the casing (3) and the existing pile (2), making it easier to pull the existing pile (2) out of the ground.
[0094]
[11] In some embodiments, the existing pile removal system (1) described in any of [7] to
[10] above, The system further includes a casing embedding device (5) for embedding the casing (3) in the ground so as to surround the outer perimeter of the existing pile (2), The casing embedding device (5) is suspended from the lifting portion (41) and is configured to detachably support the upper end portion (33) of the casing (3), and to rotate the casing (3) along the circumferential direction.
[0095] According to the configuration described in
[11] above, the existing pile (2) removal system (1) lowers the casing (3), which has been rotated by the casing embedding device (5), by a crane (4). The lower end (34) of the casing (3) excavates the ground around the existing pile (2), and the cylindrical casing (3) is embedded in the ground so as to surround the outer circumference of the existing pile (2). The casing (3) embedded in the ground severs the connection between the existing pile (2) and the ground, thereby reducing the frictional force of the ground on the existing pile (2) and making it easier to pull the existing pile (2) out of the ground.
[0096]
[12] In some embodiments, the existing pile removal system (1) described in any of [7] to
[11] above, When the outer diameter of the existing pile (2) is D1, the inner diameter D2 of the casing (3) satisfies the condition 1.2D1 ≤ D2 ≤ 1.5D1.
[0097] According to the configuration described in
[12] above, the existing pile (2) removal system (1) is configured such that the inner diameter D2 of the casing (3) satisfies the condition 1.2D1 ≤ D2 ≤ 1.5D1, thereby effectively separating the existing pile (2) from the ground by the casing (3) embedded in the ground. As a result, in the method for removing the existing pile (2) according to this embodiment, the frictional force of the ground on the existing pile (2) can be effectively reduced, and the existing pile (2) can be easily pulled out of the ground. [Explanation of Symbols]
[0098] 1. System for removing existing piles 2 Existing piles 2A Upper existing pile 2B Lower existing pile 3. Casing 4 Cranes 5. Casing embedding device 6 Water injection device 7 Pile clamping device 11 wires 12 Filling 13 weight 35 drilling blades 36 Protrusion 41 Lifting section 42 Crane body 43 Boom 51 Main body 52 Casing support section 53 Rotary drive mechanism 61 Water Injection Channel Forming Member 62 Aperture 71 Main body 72 Rotating parts 72A Rotating shaft 73 Clamping part 74 Protrusion 411 First lifting section 412 Second lifting section 413 Wire 414 Wire winding device S1 Casing embedding step S11 Casing drilling step S12 Water injection step S2 Pile Extraction Step S3 Backfilling step S4 Casing Removal Step
Claims
1. A method for removing existing piles embedded in the ground, A casing embedding step involves embedding a cylindrical casing into the ground so as to surround the outer circumference of the existing pile, The system includes, after the casing embedding step, a pile extraction step in which the existing pile is pulled out of the ground by a crane while maintaining the state in which the casing is embedded in the ground, In the aforementioned pile extraction step, The pile clamping device, which is configured to clamp the upper end of the existing pile with a portion inserted inside the casing, is used to clamp the upper end of the existing pile, and the pile clamping device is then lifted by the crane. Method for removing existing piles.
2. The aforementioned pile clamping device is The main body is configured to be suspended and supported by the aforementioned crane, The main body is supported via a rotating portion so as to be movable along the radial direction, and includes a plurality of clamping portions arranged at intervals in the circumferential direction, In the aforementioned pile extraction step, The upper end of the existing pile is clamped by the plurality of clamping portions. The method for removing existing piles according to claim 1.
3. Multiple protrusions are formed on the inner surfaces of the multiple clamping portions, with these protrusions extending from the inner surface and spaced apart along the axial direction of the pile clamping device. The method for removing existing piles according to claim 2.
4. In the aforementioned casing embedding step, The water is injected around the lower end of the casing via at least one water injection channel forming member that is supported by the casing and has an opening for discharging the injected water downward. A method for removing existing piles according to any one of claims 1 to 3.
5. The casing is longer than the existing pile. In the casing embedding step, the lower end of the casing is buried deeper in the ground than the lower end of the existing pile. A method for removing existing piles according to any one of claims 1 to 3.
6. When the outer diameter of the existing pile is D1, the inner diameter D2 of the casing satisfies the condition 1.2D1 ≤ D2 ≤ 1.5D1. A method for removing existing piles according to any one of claims 1 to 3.
7. A system for removing existing piles embedded in the ground, A crane having a lifting section, wherein the lifting section is configured to be vertically movable, A cylindrical casing is configured to surround the outer circumference of the aforementioned existing pile, The system includes a pile clamping device that is suspended from the lifting section and configured to clamp the upper end of the existing pile with a portion of it inserted into the casing, A system for removing existing piles.
8. The aforementioned pile clamping device is The main body is configured to be suspended and supported by the aforementioned crane, The main body is supported via a rotating portion so as to be movable along the radial direction, and includes a plurality of clamping portions arranged at intervals in the circumferential direction, wherein the plurality of clamping portions are configured to clamp the upper end of the existing pile. The existing pile removal system according to claim 7.
9. Multiple protrusions are formed on the inner surfaces of the multiple clamping portions, with these protrusions extending from the inner surface and spaced apart along the axial direction of the pile clamping device. The existing pile removal system according to claim 8.
10. The casing is further provided with a water injection device for injecting water around the lower end of the casing. The water injection device includes at least one water injection channel forming member that is supported by the casing and has an opening for discharging the water downwards. A system for removing existing piles according to any one of claims 7 to 9.
11. The device further comprises a casing embedding device for embedding the casing in the ground so as to surround the outer perimeter of the existing pile, The casing embedding device is suspended from the lifting section and configured to detachably support the upper end of the casing, and is configured to rotate the casing along the circumferential direction. A system for removing existing piles according to any one of claims 7 to 9.
12. When the outer diameter of the existing pile is D1, the inner diameter D2 of the casing satisfies the condition 1.2D1 ≤ D2 ≤ 1.5D1. A system for removing existing piles according to any one of claims 7 to 9.