JP6952159B1 - Pile excavation backfill method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformly mix a backfilling agent with earth and sand in the entire pile punching hole, and to fill the ground evenly after the pile punching hole is backfilled, and it is possible to reduce the construction cost. Provide a backfilling method. SOLUTION: When excavating using a casing 2, the side injection water of the existing pile is sprayed from the substantially tip side of the casing 2 to the side surface of the existing pile 7, so that the water is attached to the existing pile 7. The earth and sand can be separated from the existing pile 7 and the earth and sand in the casing 2 can be turned into mud. Then, when the casing 2 is pulled up while rotating the casing 2, the fluid cement milk is sprayed from the perforated water filler injection port 4 at the substantially tip of the casing 2, so that the cement milk is sprayed along the existing pile 7. The mixture of cement milk and muddy earth and sand is filled, and the pile punching hole can be backfilled by filling the pile punching hole almost evenly over the entire length of the pile punching hole. [Selection diagram] Fig. 1

Description

The present invention relates to a pile extraction / backfilling method in which a pile extraction hole from which an existing pile has been extracted is backfilled with a filler.

Conventionally, a pile extraction / backfilling method is known in which a pile extraction hole from which an existing pile has been extracted is backfilled with a filler. As this type of pile extraction and backfilling method, an outer circumference excavation process of excavating along the outer peripheral surface of an existing pile using an excavation casing, a casing withdrawal process of temporarily pulling out the excavation casing from the ground, and a casing withdrawal process are used. A pile pulling wire staking process in which a ring formed at one end of a pile pulling wire is entwined at the tip of the excavated casing, and an excavation casing in which the stake is entwined along the outer peripheral surface of the existing pile. Then, the pile is returned to the ground again, the ring is replaced with the existing pile from the tip of the excavation casing, and the pile removal wire is hung on the existing pile. A backfilling agent supply pipe arranging step of arranging a backfilling agent supply pipe that supplies a backfilling agent having fluidity on the outer periphery of the excavated existing pile, and a backfilling agent via the backfilling agent supply pipe. It has an existing pile pull-up backfilling step in which a pile pulling wire is pulled up while supplying and the existing pile is pulled up to fill the pile pulling hole with a backfilling agent. The backfilling agent supply pipe was connected so that the backfilling agent discharge port reached near the bottom of the pile punching hole.

By using this conventional pile punching and backfilling method, after the excavation casing is once pulled out from the ground, the existing pile is pulled up from the discharge port of the backfilling agent supply pipe arranged near the bottom of the pile punching hole. By discharging the backfilling agent, even if impurities such as groundwater, gravel, and jet water used for excavation are accumulated inside the pile punching hole, the backfilling agent discharged from the discharge port of the backfilling agent supply pipe Since it floats on the ground, it is possible to reduce the uneven filling of the backfilling agent in the ground, and it is possible to improve the ground deformation.

Japanese Patent No. 5890606

However, in the conventional pile excavation backfilling method, after the excavation casing is pulled out from the ground, the backfilling agent supply pipe is inserted into the hole at the outer periphery of the existing pile excavated by the excavation casing. If the hole on the outer periphery of the pile is broken, there is a problem that the backfilling agent supply pipe cannot be inserted. In addition, when the excavation casing is pulled out from the ground, the "dry earth and sand" adhering to the existing piles falls to the bottom of the ground, and the "dry earth and sand" is ground together with the "mud soil". Since it will be deposited on the insole and bottom surface, even if the backfilling agent is discharged from the vicinity of the bottom of the pile punching hole, it cannot be sufficiently mixed with the deposited earth and sand, and the pile punching hole after the pile punching hole is backfilled. The ground near the bottom may not be filled with sufficient backfilling agent, and the backfilling agent is discharged from the discharge port of the backfilling agent supply pipe arranged near the bottom of the pile punching hole. There is a problem that the backfilling agent and the earth and sand cannot be sufficiently mixed in the entire hole, and the ground after the pile punching hole is backfilled cannot be evenly filled with the filler. In this way, if the ground cannot be evenly filled with filler, it is not possible to sufficiently improve the ground deformation, and new pile driving is performed at the place where the ground deformation has occurred. There was a big problem that the pile driving holes excavated before the pile driving were formed obliquely, and the piles press-fitted into the ground were obliquely constructed. Further, in the conventional pile punching and backfilling method, after the excavation casing is pulled out, the backfilling agent supply pipe that supplies the backfilling agent is arranged near the bottom of the pile punching hole, so that the length of the existing pile is increased. In order to insert the discharge port of the backfilling agent supply pipe to the vicinity of the bottom of the pile punching hole when it is several meters or more, it is necessary to connect multiple backfilling agent supply pipes, and it is necessary to connect multiple backfilling agent supply pipes near the bottom of the pile punching hole. Since it takes a long time to arrange the discharge port of the backfilling agent supply pipe, there is a problem that the construction time increases and the construction cost increases.

The present invention has been made in view of the above problems, and the construction time and construction cost are not increased, and the pile can be backfilled by filling the filling material substantially evenly over the entire length of the pile punching hole by a simple method. The purpose is to provide a backfilling method.

In order to solve the above problems and achieve the above object, the first aspect of the present invention is a pile excavation backfilling method in which a pile excavation hole from which an existing pile has been extracted is backfilled with a filler. , When excavating using a casing along the outer peripheral surface of the existing pile and when excavating using the casing by the casing excavation process, from the substantially tip side of the casing toward the side surface of the existing pile. The existing pile liquid injection process in which the liquid is injected, the casing pulling process in which the casing is pulled up while rotating the casing from the excavation hole excavated in the casing excavation process, and the casing pulling process in which the casing is rotated by the casing pulling process. When being pulled up, the existing pile is pulled up after the lower casing filler injection step in which the fluid filler is injected from the filler injection port at the substantially tip of the casing and the casing pulling step are executed. The existing pile pulling process and the existing pile side filling material pouring process in which the fluid filling material is poured from the upper part of the existing pile to the side surface of the existing pile when the existing pile is pulled up by the existing pile pulling process. , And the filler injected from the substantially tip of the casing by the filler injection process at the bottom of the casing is separated from the existing pile by the existing pile liquid injection step and mixed with the muddy earth and sand around the tip of the casing. The filling material that has been filled and poured into the side surface of the existing pile by the filling material filling process on the side surface of the existing pile is filled in the vicinity of the existing pile pulled up by the pulling process of the existing pile with a small gap, so that the total length of the pile extraction hole is reached. It is characterized in that the pile punching hole can be backfilled by filling the filler substantially evenly.

According to the present invention, when excavating using the casing, the liquid is ejected from the substantially tip side of the casing toward the side surface of the existing pile, so that the earth and sand adhering to the existing pile is discharged from the existing pile. It is possible to turn the earth and sand in the casing into mud while moving away from the casing. Then, when the casing is pulled up while rotating the casing, the filler having fluidity is injected from the filler injection port at the substantially tip of the casing, so that the filler injected from the substantially tip of the casing is ejected. It is sufficiently mixed with the sediment that has been separated from the existing pile and has become muddy, and the mixture of the mixed filler and the muddy sediment is filled around the tip of the casing that is being pulled up , and the existing pile is made by the existing pile pulling process. When the pile is being pulled up, the filler having fluidity is poured from the upper part of the existing pile to the side surface of the existing pile, so that the filler poured into the side surface of the existing pile has a small gap around the existing pile being pulled up. It is filled. As a result, a mixture of the filler and the mud-soiled earth and sand is filled along the existing pile, and the filler can be filled almost evenly over the entire length of the pile extraction hole to backfill the pile extraction hole.

The second aspect of the present invention relates to the pile punching and backfilling method of the second aspect, and the existing pile pulling step is performed by a wire hooking step in which a wire is hooked on the existing pile and a wire hooking step. It has a wire pulling process in which the hooked wire is pulled up, and the existing pile is pulled up via the wire by the wire pulling process.

The third aspect of the present invention relates to the pile punching and backfilling method of the first aspect, and in the casing pulling step, the chuck claw is locked to the lower end of the existing pile in the casing. As a result, the casing is pulled up while rotating the casing together with the existing pile to which the chuck claws are locked.

The fourth aspect of the present invention relates to the pile excavation backfilling method of the first aspect, and the existing pile liquid injection step is substantially the tip of the casing during the entire period of excavation by the casing excavation step. The feature is that the liquid is sprayed from the side of the part to the side surface of the existing pile.

According to the present invention, since the liquid is sprayed from the substantially tip side of the casing to the side surface of the existing pile during the entire period of excavation by the casing excavation process, the earth and sand adhering to the existing pile is removed from the existing pile. It is possible to make it easier to separate, and it is possible to make it easier for the earth and sand in the casing to become muddy.

The fifth aspect of the present invention relates to the pile excavation backfilling method of the first aspect, and the existing pile liquid injection step is carried out from a plurality of locations on the side of substantially the tip of the casing to the side surface of the existing pile. It is characterized in that a liquid is ejected.

According to the present invention, since the liquid is sprayed onto the side surface of the existing pile from a plurality of locations on the side of the substantially tip portion of the casing, the earth and sand adhering to the existing pile can be more easily separated from the existing pile. The earth and sand in the casing can be more easily turned into mud.

The sixth aspect of the present invention relates to the pile punching and backfilling method of the first aspect, and in the casing lower filling material injection step, the casing is pulled up while rotating the casing by the casing pulling step. It is characterized in that the filler having fluidity is injected from the filler injection port at the substantially tip of the casing during the entire period.

According to the present invention, since the filler having fluidity is injected from the filler injection port at the substantially tip of the casing during the entire period in which the casing is pulled up while rotating the casing, the filler is injected from the substantially tip of the casing. It becomes easier for the filler to be mixed with the muddy earth and sand. Then, since the mixture of the sufficiently mixed filler and the mud-soil is filled around the tip of the casing in the process of being pulled up, the mixture of the filler and the mud-soil is filled along the existing pile, and the total length of the pile punching hole is completed. It is possible to fill the pile punching hole back by filling the filler almost evenly.

The seventh aspect of the present invention relates to the pile excavation backfilling method of the first aspect, wherein the liquid injected by the existing pile liquid injection step is water. ..

According to the present invention, the construction time and the construction cost are not increased, and the pile extraction hole can be backfilled by filling the filling material substantially evenly over the entire length of the pile extraction hole by a simple method.

It is a figure which shows the construction state of the existing pile pulling-out device used for the pile pulling-out backfilling method in 1st Embodiment of this invention. It is the upper perspective view of the casing of the existing pile pulling-out device used in the pile pulling-out backfilling method. It is the upper sectional view of the casing of the existing pile pulling-out device used in the pile pulling-out backfilling method. FIG. 3 is a cross-sectional view taken along the line AA of FIG. (A) It is a lower side view of the casing of the existing pile pulling apparatus used in the pile pulling backfilling method in 1st Embodiment of this invention. (B) FIG. 5B is a cross-sectional view taken along the line BB of FIG. It is a flowchart of the pile excavation backfilling method. It is a subroutine flowchart of the existing pile pulling process of the same pile excavation backfilling method. It is a figure which shows the implementation state of the casing positioning process of the pile punching backfilling method. (A) It is a figure which shows the implementation state of the casing excavation process and the existing pile liquid injection process of the pile excavation backfilling method. (B) It is a figure which shows the CC cross section of FIG. 9 (a). (C) It is sectional drawing of the DD section of FIG. 9A. (A) It is a figure which shows the implementation state of the casing pulling process and the casing lower part filler injection process of the pile punching backfilling method. (B) It is a figure which shows the EE cross section of FIG. 10 (a). (C) is a cross-sectional view of the FF section of FIG. 10 (a). It is a figure which shows the implementation state of the wire hooking process of the pile punching backfilling method. It is a figure which shows the implementation state of the wire pulling process and the existing pile side filling material pouring process of the pile punching backfilling method. It is a figure which shows the construction state of the existing pile pulling-out device used for the pile pulling-out backfilling method in 2nd Embodiment of this invention. It is a figure which shows the lower part of the casing of the existing pile pulling device. It is a figure which shows the chuck claw at the retracting position of the existing pile pulling-out device. It is a figure which shows the pulling-out situation of the existing pile using the same pile pull-out backfilling method.

(First Embodiment)
Hereinafter, the first embodiment of the pile punching and backfilling method of the present invention will be described with reference to the drawings. Here, FIG. 1 is a diagram showing a construction status of an existing pile extraction device used in the pile extraction / backfilling method according to the first embodiment of the present invention, and FIG. 2 is a diagram showing an existing pile extraction device used in the pile extraction / backfilling method. It is an upper perspective view of the casing of the apparatus, FIG. 3 is an upper sectional view of the casing of the existing pile extraction apparatus used in the pile extraction and backfilling method, and FIG. 4 is a sectional view taken along the line AA of FIG. 5 (a) is a lower side view of the casing of the existing pile extraction device used in the pile extraction and backfilling method according to the first embodiment of the present invention, and FIG. 5 (b) is a cross-sectional view taken along the line BB of FIG. ..

As shown in FIG. 1, the existing pile pulling device 1 is a machine that supports the casing 2 and moves and rotates the casing 2 up and down. As the casing 2 rotates and moves downward in this way, the ground is excavated by the excavation teeth 3 at the tip. Specifically, the existing pile pulling device 1 is a machine for pulling out an existing pile (pile) 7 buried in the ground, and is provided at the excavation teeth 3 provided at the tip of the casing 2 and at the tip of the casing 2. It has a drilled water filling material injection port 4 (4a, 4b) and an existing pile side injection nozzle 5 (5a, 5b) provided on the side of the tip of the casing 2 (see FIG. 5). Specifically, the existing pile side injection nozzles 5 (5a, 5b) are provided about 2 cm outside the outer side surface of the tip end portion of the casing 2. Here, the existing pile 7 is a pile buried in the ground as a foundation of a building or the like, for example, a cast-in-place reinforced concrete pile, a concrete-filled steel pipe pile, a PC pile manufactured in a factory, or a PHC pile. , SC piles, steel pipe piles, H steel piles, etc. Water (liquid) supplied through the side surface of the casing 2 is injected from the drilled water filler injection port 4 (4a, 4b) and the existing pile side surface injection nozzle 5 (5a, 5b). Here, water (liquid) is injected into the existing pile side injection nozzles 5 (5a, 5b) from the outer side of the casing 2 through the opening 6 (see FIG. 5B). In the present embodiment, two drilling water filler injection ports 4 (4a, 4b) and two existing pile side injection nozzles 5 (5a, 5b) are provided at symmetrical positions with respect to the central axis of the casing 2. Not limited to this, a plurality of two or more (for example, two to four, four, etc.) may be provided. Further, in the present embodiment, the existing pile side injection nozzles 5 (5a, 5b) are provided on the side of the tip of the casing 2, but the present invention is not limited to this, and the existing pile side injection nozzles 5 (5a, 5b) are provided near the tip of the casing 2 (substantially the tip). You may.

The casing 2 is made of ^{high-strength steel having a tensile strength of 490 N / mm 2} or more and is formed of a hollow cylindrical member, has a wall thickness of 3 mm to 9 mm, and has an inner diameter larger than that of the existing pile 7. Further, as described above, the drilling water filler injection port 4 (4a, 4b) is provided at the tip of the casing 2, and the existing pile side injection nozzle 5 (5a) is provided on the outer side of the tip of the casing 2. 5b) is provided. Further, a swivel 8 is provided at the rear end of the casing 2, and a swivel in-hole drilling water filling material flow path 8x in the swivel 8 or an existing pile side injection water flow path 8y in the swivel is provided from the upper part to the side surface of the casing 2. A drilling water filling material flow path 9 or an existing pile side injection water flow path 10 for supplying drilling water (liquid) or cement milk (filling material) or existing pile side injection water (liquid) is provided through the hole. (See FIG. 2). Here, in FIGS. 2, 3 and 4, for convenience of explanation, the directions of the casing 2 and the like are different from those of FIGS. 1 and 5.

The swivel 8 is a double-tube swivel whose inside is composed of an inner pipe and an outer pipe. Inside the swivel 8 is a drilling water or cement supplied to the drilling water filler injection port 4 (4a, 4b). Swivel inner perforation of milk (filling material) A water filling material flow path 8x is formed, and the side surface of the existing pile supplied to the existing pile side injection nozzle 5 (5a, 5b) between the inner pipe and the outer pipe of the swivel 8. An existing pile side injection water flow path 8y in the swivel of the injection water is formed. The swivel 8 has a hole-drilled water or cement milk (filling) whose inlet side is supplied from a source of drilling water or cement milk (filling material) (not shown) or a source of existing pile side jet water (not shown), respectively. Material) or existing pile side jet water supply pipes 11a, 11b, 12 (hose), and the outlet side is provided from the inside of the casing 2 to the side surface of the perforated water or cement milk (filling material) or the existing It is connected to the drilled water filling material flow path 9 which is the flow path of the pile side injection water and the existing pile side injection water flow path 10. Then, the water (liquid) or cement milk (filler) supplied to the drilling water filling material flow path 9 or the existing pile side jet water flow path 10 is branched into two paths at the upper part of the casing 2, and the drilling water is formed. It is sent to the filler injection port 4 (4a, 4b) or the existing pile side injection nozzle 5 (5a, 5b). In this way, the drilling water or cement milk (filler) or the existing pile side jet water supplied from the source of the drilling water or cement milk (filler) or the existing pile side jet water (not shown), respectively, Each supply pipe 11a, 11b, 12 → swivel 8 → each flow path 9, 10 → 2 paths through each flow path 9 (9a, 9b), 10 (10a, 10b), drilled water filler injection port 4 (4a) It is injected from 4b) or the existing pile side injection nozzle 5 (5a, 5b), respectively. In the present embodiment, the drilling water or cement milk (filling material) is sprayed from the drilling water filler injection port 4 (4a, 4b), but the present invention is not limited to this, and the drilling water and cement milk (filling) are not limited to this. The material) may be injected from separate injection ports (drilled water injection port, filler injection port).

A plurality of excavation teeth 3 are provided at the tip of the casing 2 and excavate the ground when the casing 2 is made to enter the ground.

The earth auger 13 rotates and drives the casing 2 and is provided on the upper portion of the casing 2 (see FIG. 1). In this earth auger 13, a wire 14e is suspended from a top sheave 14d above the leader 14c of the base machine 14 (for example, a three-point pile driver), and a guide rail (not shown) provided on the side surface of the leader 14c of the base machine 14. ) Is supported so that it can be raised and lowered. A drive source (motor), a speed reducer, and the like are provided in the case 13a of the earth auger 13, and a rotary shaft 15 that rotates by the rotational driving force of the drive source is provided in the lower part of the case 13a. A swivel 8 is connected to the lower end of the rotating shaft 15. Then, the casing 2 is rotated around an axis (the central axis of the cylindrical casing 2) by the earth auger 13, and the casing 2 is lowered along a guide rail (not shown) on the side surface of the leader 14c of the base machine 14. The ground is excavated by the excavation teeth 3 at the tip of the casing 2, and the casing 2 can enter the ground. Further, by pulling up the earth auger 13 along the guide rail (not shown) by the wire 14e, the casing 2 that has entered the ground by the base machine 14 can be pulled out to the ground. The leader 14c of the base machine 14 is supported by the back stay 14a from the rear, and the lower end portion of the leader 14c is rotatably supported by the pin 14b. Then, by expanding and contracting the back stay 14a, the leader 14c can be tilted in the front-rear direction with the pin 14b at the lower end of the leader 14c as an axis. In this embodiment, the earth auger 13 is used, but the present invention is not limited to this, and a drive device other than the earth auger 13 may be used.

Hereinafter, the pile punching and backfilling method according to the first embodiment of the present invention will be described with reference to the drawings. Here, FIG. 6 is a flowchart of the pile pulling backfilling method according to the embodiment of the present invention, FIG. 7 is a subroutine flowchart of the existing pile pulling process of the pile pulling backfilling method, and FIG. 8 is a flowchart of the pile pulling back. FIG. 9A is a diagram showing the implementation status of the casing positioning step of the backfilling method, and FIG. 9A is a diagram showing the implementation status of the casing excavation step and the existing pile liquid injection process of the pile removal backfilling method. b) is a view showing a CC cross section of FIG. 9 (a), FIG. 9 (c) is a cross section of a DD section of FIG. 9 (a), and FIG. 10 (a) is a pile removal. It is a figure which shows the implementation state of the casing pulling process and the casing lower part filler injection process of the backfilling method, FIG. 10 (b) is a figure which shows the EE cross section of FIG. ) Is a cross-sectional view of the FF section of FIG. 10 (a). Here, with respect to FIGS. 8 to 10, for convenience of explanation, the casing 2 and the like are enlarged and displayed.

First, in S1, the casing positioning step is carried out. In this casing positioning step, the tip end portion of the casing 2 is positioned at a position where the upper end of the existing pile 7 can be inserted into the casing 2 (see FIG. 8). Specifically, the base machine 14 is used to move the lower end of the casing 2 to the upper end position of the existing pile 7. Here, before the casing positioning step is performed, the existing pile 7 is cueed using an excavator such as a backhoe (not shown). Then, when the casing 2 is positioned in a predetermined manner, the process proceeds to S2.

In S2, the casing excavation step is carried out. In this casing excavation step, the casing 2 is excavated along the outer peripheral surface of the existing pile 7 (see FIG. 9A). Here, the casing excavation process is started when the excavation button (not shown) is turned “ON”. Specifically, when the excavation button (not shown) is turned “ON”, the casing 2 rotates. Then, while the drilling water (liquid) is injected from the drilling water filler injection port 4 (4a, 4b) at the tip of the casing 2, the ground is excavated by the excavating teeth 3 at the tip of the casing 2, and the casing 2 is formed. It enters (descends) into the ground along the existing pile 7. In this way, by injecting the drilling water (liquid) from the drilling water filler injection port 4 (4a, 4b) at the tip of the casing 2, the earth and sand at the tip of the casing 2 becomes muddy, and the casing 2 is more likely to enter (descend) into the ground (see FIG. 9 (c)). Then, the process proceeds to S3.

In S3, the existing pile liquid injection step is carried out. In this existing pile liquid injection step, when excavating using the casing 2, the existing pile side injection water (liquid) is injected from the side of the tip of the casing 2 to the side surface of the existing pile 7 (FIG. 9 (FIG. 9). b) See). Here, the existing pile liquid injection process is started when the existing pile injection water button (not shown) is turned “ON”. Specifically, when the existing pile injection water button (not shown) is turned “ON”, the existing pile side injection nozzle 5 (5a, 5b) on the side of the tip of the casing 2 passes through the opening 6 of the existing pile. The existing pile side jet water (liquid) is sprayed onto the side surface of No. 7 (see FIG. 9B). In this way, by injecting the existing pile side injection water (liquid) from the side of the tip of the casing 2 to the side surface of the existing pile 7, the earth and sand adhering to the existing pile 7 is separated from the existing pile 7 and at the same time. The earth and sand in the casing 2 can be turned into mud. In the present embodiment, the existing pile side injection nozzle 5 (5a, 5b) on the side of the tip of the casing 2 injects the existing pile side injection water (liquid) onto the side surface of the existing pile 7, as described above. The existing pile side injection nozzle 5 (5a, 5b) on the substantially tip side of the casing 2 may inject water (liquid) from the existing pile side injection nozzle 5 onto the side surface of the existing pile 7. Further, in the present embodiment, the existing pile liquid injection process is carried out for the entire period during which the casing excavation process is carried out, but the present invention is not limited to this, and some of the casing excavation steps are carried out. The existing pile liquid injection process may be carried out during the period. That is, "when excavating using the casing 2 by the casing excavation process" means within the period from the start to the end of the casing excavation process, and ends after the casing excavation process is started. If it is within the period until the excavation is completed, not only the entire period in which excavation is started by the casing excavation process but also a part of the period is included. Further, in the present embodiment, the "existing pile liquid injection process" is executed when the existing pile injection water button (not shown) is turned "ON", but the present invention is not limited to this, and the excavation button (not shown) is not limited to this. When is set to "ON", the "casing excavation process" and the "existing pile liquid injection process" may be executed. Then, the process proceeds to S4.

In S4, it is determined whether or not the casing 2 has excavated the lower end of the existing pile 7. That is, when the casing 2 excavates the ground, it is determined whether the entire length of the existing pile 7 is contained in the casing 2. Since the length of the existing pile 7 is known in advance as to "whether the total length of the existing pile 7 is contained in the casing 2", the "tip portion of the casing 2 from the reference position" displayed on the length display unit (not shown). It can be judged from the value of "length up to". Then, if it is determined to be "NO" in S4, the process proceeds to S2, and the processes of S4 → S2 → S3 → S4 are repeatedly executed until it is determined to be “YES” in S4, and it is determined to be “YES” in S4. If so, proceed to S5. Here, the casing excavation step (S2) is executed while adding a new casing to the casing 2. In this embodiment, the tip of the casing 2 is displayed from the reference position displayed on the length display unit (not shown) of the management device (not shown) as to "whether the total length of the existing pile 7 is contained in the casing 2". Judgment is made from the value of the length up to the part, but the judgment is not limited to this, and may be judged by another method.

In S5, the casing excavation completion step is carried out. Here, in the casing excavation completion step, the rotation of the casing 2 is stopped, and the injection of the drilling water (liquid) from the drilling water filler injection port 4 (4a, 4b) at the tip of the casing 2 is also stopped. Further, the injection from the existing pile side injection nozzle 5 (5a, 5b) on the side of the tip of the casing 2 is also stopped. This casing excavation completion step is carried out by turning off the "excavation button (not shown)" and the "existing pile injection water button (not shown)". In the present embodiment, the casing excavation completion step is carried out by turning off the “excavation button (not shown)” and the “existing pile injection water button (not shown)”, but as described above. , The "excavation button (not shown)" may be turned "OFF" to carry out the operation. Then, the process proceeds to S6.

In S6, the casing pulling step is carried out. In this casing pulling step, the casing 2 is pulled up while rotating the casing 2 from the excavation hole 26 excavated by the casing excavation step (see FIG. 10A). In this casing pulling step, the earth auger 13 is raised by pulling the wire 14e along the guide rail (not shown) while rotating the casing 2 by the earth auger 13, whereby the casing 2 that has entered the ground is raised. Is pulled up to the ground. Then, the process proceeds to S7.

In S7, the casing lower filler injection step is carried out. In this casing lower part filler injection step, when the casing 2 is pulled up while rotating the casing 2 by the casing pulling step, the cement milk (filler) having fluidity is the perforated water at the substantially tip of the casing 2. It is injected from the filler injection port 4 (4a, 4b) (see FIG. 10A). Specifically, cement milk (from the swivel 8 at the top of the casing 2 to the perforated water filler injection port 4 (4a, 4b) via the perforated water filler flow path 9 (9a, 9b) on the side surface of the casing 2 ( Filler) is sprayed (see FIG. 10 (c)). In this way, when the casing 2 is pulled up while being rotated, the fluid cement milk (filler) is sprayed from the perforated water filler injection port 4 (4a, 4b) at the substantially tip of the casing 2. Therefore, the cement milk (filler) jetted from the perforated water filler injection port 4 (4a, 4b) at the substantially tip of the casing 2 is mixed with the mud-ized earth and sand. Then, the mixed cement milk (filler) and the mud-soiled earth and sand are filled around the tip of the casing 2, so that the cement milk (filler) is filled along with the tip of the casing 2 along the existing pile 7. And a mixture of mud and earth and sand are filled. In the present embodiment, cement milk is used as the filler, but the present invention is not limited to this, and mortar may be used, or cement milk or mortar mixed with a fluidizing agent for pumping may be used. good. Further, in the present embodiment, as described above, the drilling water or the cement milk (filling material) is sprayed from the drilling water filler injection port 4 (4a, 4b), but the present invention is not limited to this. And cement milk (filler) may be sprayed from separate injection ports (drilled water injection port, filler injection port). Then, the process proceeds to S8.

In S8, it is determined whether the casing 2 is pulled up from the excavation hole 26 to the ground. That is, it is determined whether the lower end of the casing 2 has been pulled up to the ground. Then, if it is determined to be "NO" in S8, the process proceeds to S6, and the processes of S8 → S6 → S7 → S8 are repeatedly executed until it is determined to be “YES” in S8, and it is determined to be “YES” in S8. If so, proceed to S9. Then, when it is determined that the casing 2 has been pulled up from the excavation hole 26 to the ground, the "stop button (not shown)" is pressed at that timing. In the present embodiment, it is determined that the casing 2 is pulled up from the excavation hole 26 to the ground by "the lower end of the casing 2 is pulled up to the ground", but the present invention is not limited to this, and "the lower end of the casing 2 is pulled up". It may be determined that the casing 2 has been pulled up from the excavation hole 26 to the ground by "pulling up to the upper end portion of the existing pile 7 (for example, a portion about 3 m from the upper end)".

In S9, the existing pile pulling process is carried out. In this existing pile pulling process, the existing pile is pulled up. The specific contents of the existing pile pulling process will be described with reference to FIGS. 7, 11, and 12. Here, as described above, FIG. 7 is a subroutine flowchart of the existing pile pulling process of the pile pulling backfilling method according to the embodiment of the present invention, and FIG. 11 shows the wire hooking step of the pile pulling backfilling method. It is a figure which shows the implementation state, and FIG.

In S91, the wire hooking step is carried out. In this wire hooking process, the wire 16a is hooked on the existing pile 7. Specifically, a ring of a wire 16a for pulling a pile is entwined around an excavation tooth 3 at the tip of the pulled casing 2, and the other end of the wire 16a is hung on a wire hook 17b of a crawler crane 17a. Then, by returning the casing 2 to the ground again, the ring of the wire 16a is hung on the upper end portion (a portion about 3 m from the upper end) of the existing pile 7 (see FIG. 11A). That is, the wire 16a hung on the wire hook 17b is loosened, the wire 16a entwined around the excavation tooth 3 at the tip of the casing 2 is removed from the tip of the casing 2, and the wire hook 17b is raised to re-raise the wire 16a. By being stretched, the loop of the wire 16a is hung on the existing pile 7 (FIG. 11 (b)). Then, the process proceeds to S92.

In S92, the wire pulling step is carried out. In this wire pulling process, the wire 16a hooked on the existing pile 7 is pulled up by the wire hooking process. Specifically, the wire 16a hooked on the existing pile 7 is pulled up by the crawler crane 17a, and the existing pile 7 is pulled up. In this way, the existing pile 7 is pulled up from the ground via the wire 16a. Here, when the existing pile 7 is heavy, the wire 16a is pulled up by the crawler crane 17a, another wire 16b is entwined with the existing pile 7, and the entangled wire 16b is pulled by the multi-pulley 18. It may be (see FIG. 12). In this way, by pulling the existing pile 7 via the wire 16b using the multi-pulley 18, even a heavy existing pile 7 can be pulled up. If the existing pile 7 is heavier, another wire (not shown) may be entwined with the existing pile 7 and the entwined wire (not shown) may be pulled by another multi-pulley (not shown). good. Then, the process proceeds to S9.

In S10, the existing pile side filler pouring step is carried out. In this existing pile side filling material pouring step, when the existing pile 7 is pulled up by the existing pile pulling step (S9), the cement milk (filling material) having fluidity is poured into the side surface of the existing pile 7. Specifically, cement milk (filler) is poured from the upper part of the existing pile 7 to the periphery of the existing pile 7 (see FIG. 12). In this way, when the existing pile 7 is pulled up by the existing pile pulling step (S9), the cement milk (filler) having fluidity is poured into the side surface of the existing pile 7, so that the existing pile 7 The cement milk (filler) poured into the side surface is filled around the existing pile 7 being pulled up with a small gap. As a result, the pile extraction hole 19 can be backfilled by filling cement milk (filler) substantially evenly over the entire length of the pile extraction hole 19. Further, in the present embodiment, it has been described that the existing pile side filler pouring process is carried out for the entire period during which the existing pile 7 is being pulled up, but the present invention is not limited to this, and the existing pile 7 is being pulled up. The existing pile side filler pouring process may be carried out for a part of the period. That is, "when the existing pile is pulled up by the existing pile pulling process (S9)" means within the period from the start to the end of the wire pulling process, and the wire pulling process is performed. If it is within the period from the start to the end, not all the period during which the existing pile 7 is pulled up by the wire pulling process, but also a part of the period is included. Then, the process proceeds to S11.

In S11, it is determined whether all the wires 16a have been pulled up. If it is determined to be "NO" in S11, the process proceeds to S9, and the processes of S11 → S9 → S10 → S11 are repeatedly executed until it is determined to be “YES” in S11, and if it is determined to be “YES” in S11. The pile removal and backfilling method is completed. In the present embodiment, the wire 16a hooked on the existing pile 7 is continuously pulled up at once, but the present invention is not limited to this, and when the weight of the existing pile 7 is heavy, the existing pile 7 is pulled by the wire 16a. The pulling of the wire 16a may be stopped when the wire 16a is being pulled, the upper part of the existing pile 7 may be cut during the stop, and the existing pile 7 may be divided and removed.

As described above, when the ground is excavated using the casing 2, the existing pile side injection water (liquid) is sprayed from the side of the tip of the casing 2 to the side surface of the existing pile 7, so that the existing pile The earth and sand adhering to the 7 can be separated from the existing pile 7 and the earth and sand in the casing 2 can be turned into muddy soil. Then, when the casing 2 is pulled up while being rotated, the fluid cement milk (filler) is sprayed from the perforated water filler injection port 4 (4a, 4b) at the substantially tip of the casing 2. , The cement milk (filler) sprayed from the substantially tip of the casing 2 is sufficiently mixed with the muddy earth and sand, and the mixture of the mixed cement milk (filler) and the muddy earth and sand is being pulled up from the casing 2 It is filled around the tip of the casing. As a result, a mixture of cement milk (filler) and mud-soiled earth and sand is filled along the existing pile 7, and cement milk (filler) is filled almost evenly over the entire length of the pile pull-out hole 19 to backfill the pile pull-out hole 19. Can be done. Further, when the existing pile 7 is pulled up by the existing pile pulling step (S9), the cement milk (filler) having fluidity is poured into the side surface of the existing pile 7, so that it is applied to the side surface of the existing pile 7. The poured cement milk (filler) is filled around the existing pile 7 being pulled up with a small gap. As a result, the pile extraction hole 19 can be backfilled by filling cement milk (filler) substantially evenly over the entire length of the pile extraction hole 19.

(Second Embodiment)
Next, a second embodiment of the pile punching and backfilling method of the present invention will be described with reference to the drawings. Here, FIG. 13 is a diagram showing the construction status of the existing pile extraction device used in the pile extraction and backfilling method according to the second embodiment of the present invention, and FIG. 14 is a diagram showing the lower part of the casing of the existing pile extraction device. FIG. 15 is a diagram showing a chuck claw at a retracted position of the existing pile extraction device, and FIG. 16 is a diagram showing a pulling state of an existing pile using the pile extraction and backfilling method.

The difference between the second embodiment and the first embodiment of the present invention is that in the first embodiment of the present invention, the wire 16a is hooked on the existing pile 7, and the existing pile 7 is pulled up by pulling up the wire 16a. In the second embodiment, the chuck claw 22 is locked to the lower end of the existing pile 7 in the casing 21, and the casing 21 is pulled up to be locked to the chuck claw 22. The difference is that the stake 7 is pulled up. Here, as the existing pile pulling device 20 of the second embodiment, the existing pile pulling device (main structure) described in Japanese Patent No. 6596608 is used. In addition, about the 2nd Embodiment, the part different from the 1st Embodiment will be described, and the description of the same structure as the 1st Embodiment will be omitted.

First, the existing pile drawing device 20 according to the second embodiment of the present invention will be described. As shown in FIGS. 13 and 14, a communication hole (not shown) through which the chuck claw 22 can pass is formed in the hollow tip portion of the casing 21 by communicating the inner peripheral surface and the outer peripheral surface of the casing 21. ing. The chuck claw 22 is provided near the tip end portion on the outer peripheral side of the casing 21, and is a “protruding position (FIG. 16 (b)) which is a position where the tip end portion protrudes into the casing 21 through a communication hole (not shown) of the casing 21. ) ”And the“ retracted position (see FIG. 15A) ”, which is the position where the tip portion retracts outward from the inside of the casing 21. That is, at the "retracted position" of the chuck claw 22, the tip portion is retracted from the inside of the casing 21 to the outer peripheral side (see FIG. 15), and at the "protruding position" of the chuck claw 22, the inside of the casing 21 is passed through a communication hole (not shown). The tip of the casing is projected into the casing 21 (see FIGS. 16 (b) and 16 (c)). As described above, when the existing pile 7 is pulled out, the chuck claw 22 protrudes into the casing 21 and the existing pile 7 is locked by the chuck claw 22 from below (see FIG. 16).

As shown in FIG. 14, the hydraulic jack 23 is fixed to the outer peripheral portion of the casing 21 and connected to the other end of the rod 24, and the rod 24 is pressed toward the tip of the casing 21 to push the chuck claw 22. It moves from the retracted position to the protruding position, and has a piston rod 23a and a jack main body 23b (see FIG. 14). The pressing of the rod 24 is performed by supplying or discharging hydraulic oil to the hydraulic jack 23 via the swivel 8. Then, the chuck claw 22 can be moved to the "protruding position" by extending the piston rod 23a in the jack body 23b from the state where the chuck claw 22 is in the "retracted position" (see FIG. 16). Further, the chuck claw 22 can be moved to the "retracted position" by contracting the piston rod 23a in the jack body 23b from the state where the chuck claw 22 is in the "protruding position" (see FIG. 15). Here, as for the "swivel", the swivel 8 of the first embodiment is used, but other swivels may be used.

Next, the casing pulling process of the existing pile pulling process using the existing pile pulling device 20 will be described. Here, FIG. 16 is a diagram showing a pulling-up situation of an existing pile using the same pile excavation backfilling method as described above. Here, in the second embodiment, the processes from the "casing positioning step (S1)" to the "casing pulling determination (S8)" are executed, and after the "existing pile pulling step (S9)" of the first embodiment. The processing of is not included in the second embodiment.

In the casing pulling step (S6), the chuck claw 22 is locked to the lower end of the existing pile 7 in the casing 21, so that the casing 21 is pulled up together with the existing pile 7 to which the chuck claw 22 is locked. Specifically, the hydraulic jack 23 is driven to extend the piston rod 23a, and the chuck claw 22 is moved from the “retracted position (see FIG. 15)” to the “protruding position (see FIG. 16)”. As a result, the existing pile 7 is locked to the chuck claw 22 at the tip of the casing 21. Then, in this state, the existing pile 7 is pulled out together with the casing 21 by raising the casing 21 while rotating it by the base machine 14. Then, the process proceeds to S7. Since the processing of S7 and the processing of S8 are the same as those of the first embodiment, the description thereof will be omitted.

As described above, when the ground is excavated using the casing 21, the existing pile side injection water (liquid) is sprayed from the side of the tip of the casing 21 to the side surface of the existing pile 7, so that the existing pile The earth and sand adhering to the 7 can be separated from the existing pile 7 and the earth and sand in the casing 21 can be turned into muddy soil. Then, when the casing 21 is rotated and pulled up together with the existing pile 7, the fluid cement milk (filler) is discharged from the perforated water filler injection port 4 (4a, 4b) at the substantially tip of the casing 21. Since it is sprayed, the cement milk (filler) sprayed from the substantially tip of the casing 21 is sufficiently mixed with the mud-soiled earth and sand, and the mixed cement milk (filler) and the mud-soiled earth and sand are mixed in the casing. It is filled around the tip of 21. As a result, a mixture of cement milk (filler) and mud-soiled earth and sand is filled along the existing pile 7, and cement milk (filler) is filled almost evenly over the entire length of the pile pull-out hole 19 to backfill the pile pull-out hole 19. Can be done.

It should be considered that the embodiments disclosed this time are exemplary in all respects and not restrictive. The scope of the present invention is shown by the scope of claims rather than the above description, and it is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

1 Existing pile extraction device 2 Casing 3 Excavation teeth 4a Drilling water filling material injection port 4b Drilling water filling material injection port 5a Existing pile side injection nozzle 5b Existing pile side injection nozzle 6 Opening 7 Existing pile 8 Swivel 8x Swivel internal cutting Hole water filling material flow path 8y Side injection water flow path of existing pile in swivel 9 Drilling water filling material flow path 10 Existing pile side injection water flow path 11a Supply pipe 11b Supply pipe 12 Supply pipe 13 Earth auger 13a Case 14 Base machine 14a Backstay 14b Pin 14c Leader 14d Top Sheave 14e Wire 15 Rotating Shaft 15a Management Device Main Body 15b Management Device Display 16a Wire 16b Wire 17a Crawler Crane 17b Wire Hook 18 Multi-stakeur 19 Pile Extraction Hole 20 Existing Pile Extraction Device 21 Casing 22 Chuck Claw 23 Hydraulic Jack 23a Piston rod 23b Jack body 24 Rod 26 Drilling hole

Claims (7)

This is a pile removal and backfilling method in which the pile removal holes from which existing piles have been pulled out are backfilled with a filler.
Casing excavation process, which is excavated using a casing along the outer peripheral surface of an existing pile,
An existing pile liquid injection step in which liquid is injected from the substantially tip side of the casing toward the side surface of the existing pile when excavating using the casing by the casing excavation step.
A casing pulling process in which the casing is pulled up while rotating the casing from the excavation hole excavated by the casing excavation process.
When the casing is pulled up while rotating the casing by the casing pulling step, the filler having fluidity is injected from the filler injection port at the substantially tip of the casing, and the casing lower filler injection step.
After the casing pulling step is executed, the existing pile pulling step in which the existing pile is pulled up and the existing pile pulling step
When the existing pile is pulled up by the existing pile pulling step, the existing pile side filling material pouring process is provided in which the filler having fluidity is poured from the upper part of the existing pile to the side surface of the existing pile.
The filler injected from the substantially tip of the casing by the casing lower part filler injection step is filled around the tip of the casing in a state of being separated from the existing pile by the existing pile liquid injection step and mixed with the muddy earth and sand . Then, the filling material poured into the side surface of the existing pile by the filling material filling material on the side surface of the existing pile is filled around the existing pile pulled up by the pulling step of the existing pile with a small gap, so that the total length of the pile extraction hole is reached. A pile punching and backfilling method characterized in that the filling material can be filled almost evenly and the pile punching holes can be backfilled. The existing pile pulling process is
The wire hooking process, in which the wire is hooked on the existing pile,
It has a wire pulling process in which the wire hooked by the wire hooking step is pulled up.
The pile punching and backfilling method according to claim 2, wherein the existing pile is pulled up via the wire by the wire pulling step. The casing pulling step is characterized in that the chuck claw is locked to the lower end of the existing pile in the casing, so that the casing is pulled up while rotating the casing together with the existing pile to which the chuck claw is locked. The pile removal and backfilling method according to claim 1. The pile according to claim 1, wherein the existing pile liquid injection step is characterized in that liquid is injected from the substantially tip side of the casing to the side surface of the existing pile during the entire period of excavation by the casing excavation step. Unfilling and backfilling method. The pile removal and backfilling method according to claim 1, wherein the existing pile liquid injection step is characterized in that liquid is injected onto the side surface of the existing pile from a plurality of locations on the side of substantially the tip of the casing. In the casing lower part filler injection step, the filler having fluidity is injected from the filler injection port at the substantially tip of the casing during the entire period in which the casing is pulled up while rotating the casing by the casing pulling step. The pile punching and backfilling method according to claim 1, wherein the method is characterized by the above. The pile removal and backfilling method according to claim 1, wherein the liquid injected by the existing pile liquid injection step is water.

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