JP3357612B2 - Ground improvement method using rotating pile - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for constructing a sand pile for improving the ground, and more particularly to a method for constructing a sand pile free from vibration pollution and noise pollution.

[0002]

2. Description of the Related Art A method of constructing a sand pile using a pipe pile is as follows. A steel pipe pile is penetrated to a depth necessary for countermeasures against liquefaction of the ground, an appropriate amount of sand is poured into the steel pipe pile, and the pipe pile is pulled out at an appropriate distance. The pipe pile is lowered, and the sand is compacted in the hole. In other words, the sand is piled up, the pipe pile is pulled out and lowered, and the sand is compacted repeatedly to form the compacted sand pile to the ground surface. In the prior art, there are the following means for penetrating the pipe pile into the ground and for compacting the sand. 1. Impact method (hammering method)-hammering a steel pipe pile with a hammer. 2. Vibration method (vibro method). ――Driving is performed by continuous vibration by the vibration motor provided at the top of the steel pipe pile. 3. A method of press-fitting a simple steel pipe pile without a drilling blade is disclosed.

[0003]

Among the above-mentioned prior arts, the shock method and the vibration method are methods of construction that always involve intense vibration and noise, and in urban areas and the like, vibration and noise pollution are caused and stress is exerted on neighboring residents. It is. Today, due to the Pollution Control Law and the like, it has been difficult to adopt it in urban areas, and there is an urgent need for a method of forming sand piles that is free from vibration and noise pollution. In addition, the method of press-fitting a simple steel pipe pile without excavating wings has a very large resistance and requires a very large device for press-fitting and pulling out a steel pipe pile.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and has as its object to provide a sand compaction system which is free from vibration and noise and which can easily manage the compaction state of sand with torque. It is to provide a method of pile construction.

[0005]

To achieve the above object, the first invention is as follows. (1) A pipe pile having a drilling blade at the tip is set at a predetermined position, and an on- off valve is provided at the tip of the pipe pile, and the on-off valve is closed to open and close.
Pressing the sand at the bottom of the valve to form a sand plug and close the tip of the pipe pile,
Pipe pile setting process, (2) Pile intrusion process to press-fit the pipe pile to the depth required for liquefaction countermeasures, and (3) Inject appropriate amount of sand into the pipe pile and reverse the pipe pile. Forming a perforated part by pulling out to an appropriate part while rotating, opening the on-off valve and extruding the injected sand into the perforated part, a sand extrusion step,
(4) A compacting step of press-fitting the pipe pile in the forward rotation and compacting the sand, and repeating the above-mentioned sand input / extruding / compacting step, thereby forming the compacted sand pile to a predetermined portion such as the ground surface. A ground improvement method using rotating piles, characterized by being constructed.

[0006] The second aspect of the present invention is: (1) A pipe pile having a drilling blade at the tip is set at a predetermined position, and the pipe pile is placed at the tip of the pipe pile.
On-off valve and bottom block that can be removed below the bottom
Installing the components, closing the on-off valve and closing the pipe pile tip side, pipe pile setting process; (2) Pile penetration press-fitting the pipe pile to the depth necessary for liquefaction countermeasures; (3) An appropriate amount of sand is put into the pipe pile, the pipe pile is pulled out to an appropriate location while rotating the pipe pile in the reverse direction, a perforated part is formed, the on- off valve is opened, and the bottom plug member is opened.
And the bottom of the pipe pile are released.
A sand extruding step of extruding the material into the perforated portion, and (4) a compacting step of compacting the sand by press-fitting the pipe pile in a forward rotation, and repeating the sand charging, extruding and compacting steps to obtain ground. A ground improvement method using a rotating pile, characterized by forming a sand pile compacted to a predetermined portion such as the surface.

[0007]

FIG. 1 is a cross-sectional view showing an internal structure of a steel pipe pile according to a first embodiment of the present invention, and FIG.
3 to 3 are construction procedure diagrams according to the first embodiment of the present invention. In FIG. 1, an on-off valve 3 is provided below and inside a steel pipe pile (casing) 2, and a pipe 4 for ejecting compressed air or a water jet having a mouth positioned downward is provided above the on-off valve 3. ing. When the pile pipe 2 is press-fitted (down) in the forward rotation, the on-off valve 3 is closed, the sand put in the upper part is held on the upper part, and the sand in the lower part is compacted to form a sand plug. When the pipe pile 2 rotates in the reverse direction (ascends), the on-off valve 3 is opened, and compressed air or a water jet is jetted from the mouth of the pipe 4 to push out the plugged sand and the sand on the on-off valve 3 into the perforated portion B. That is, when setting the sand plug on the ground, the on-off valve 3 is in a closed state, but when pulling out the pipe pile 2, the on-off valve 3 is opened and at the same time, compressed air or water jet is jetted out. Push the sand down. At the time of re-pressing, the on-off valve 3 is in a closed state, and the sand is compacted (compressed).

2 and 3 (the pipe 4 and the on-off valve are not shown): (1) The pipe pile 2 having the excavating blade 1 on the outside of the tip is set at a predetermined position, and the on-off valve 3 is closed. Then, the sand is compacted to form a sand plug A at the tip of the pipe pile 2, and the sand plug is suppressed by the on-off valve 3. (Pile setting process) (2) Press-fit the pipe pile 2 forward to the depth required for liquefaction countermeasures. (Pile penetration process) (3) Input a certain amount of sand. (4) While pulling out or pulling out the pipe pile 2 to an appropriate position while rotating the pipe pile 2 in reverse, open the on-off valve 3 and blow compressed air or water jet from the pipe 4 onto the sand and the faucet A to pull the pipe pile 2. The sand is pushed out to the perforated portion B formed below the pipe pile 2 by pulling. (Sand Extrusion Process) (5) The pipe pile 2 is press-fitted in the forward rotation to compact the sand. (6) An appropriate amount of sand is put into the pipe pile 2, and the pipe pile 2 is rotated in the reverse direction to pull out the pipe pile 2 to an appropriate portion, or while an appropriate amount of sand is injected into the pipe pile 2. The pipe pile 2 is pulled out to an appropriate position, the pipe pile 2 is press-fitted in a forward rotation, and the sand is pushed out into the perforated portion B and compacted. (Sand injection, extrusion, compaction process) By repeating the sand injection, extrusion, compaction process,
A sand pile C compacted to a predetermined portion such as the ground surface is created. For extruding and compacting the sand, the pipe pile 2 is slightly raised by reverse rotation, and repeatedly extruded and compacted by positive rotation press-fitting, whereby higher consolidation can be achieved.

<Second Embodiment> FIG. 4 is a sectional view showing an internal structure of a steel pipe pile according to a second embodiment of the present invention. Pipe pile 2
A convex stopper 10 is provided on the inside of the bottom of the. The bottom plug member 11 made of a plate member is placed at the setting position of the pipe pile 2, and the pipe pile 2 is covered and set. The pipe pile 2 is press-fitted in the forward rotation to penetrate the ground. At this time, the bottom closing member 11 is stopped by the convex stopper 10 to prevent the soil from entering the pile and protect the on-off valve 3 from high pressure. When the pipe pile 2 is penetrated to the position for preventing liquefaction, sand is charged and the pipe pile 2 is rotated in the reverse direction, and the pipe pile 2 is pulled out to an appropriate portion. At this time, the bottom plug member 11 is the pipe pile 2
Away from the perforation. Subsequent steps are the same as in the first embodiment, and a description thereof will be omitted.

[0010]

The ground improvement method using the rotating pile according to the present invention is as described above, and has the following effects. Since the pipe pile is rotated and press-fitted to penetrate the pipe pile and compact the sand, there is no vibration or noise, and the construction can be carried out without any risk even in an urban area. In addition, since the ground penetrates while excavating the ground with the excavation blade at the tip, penetration into the ground is improved as compared with the impact method, the vibration method, or the simple press-fitting method, so that the operation and the work can be performed easily. In addition, the compaction force of the sand can be easily controlled by the torque of the motor, and the construction can be performed while more accurately responding to the construction situation and the ground condition. From the above, the ease of ground improvement is remarkably improved as compared with the related art. Since sand piles larger than the diameter of the drilling blade can be created,
Construction with steel pipe piles thinner than conventional steel pipe piles becomes possible,
Transport, transportation, setting, etc. are facilitated.

The same effect as described above can also be obtained in a method using a pipe pile whose bottom is closed by a bottom closing member that can be removed. The one using the bottom blocking member reduces the load on the on-off valve and improves the durability.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an internal structure of a steel pipe pile according to Embodiment 1 of the present invention.

FIG. 2 is a construction procedure diagram according to the first embodiment of the present invention.

FIG. 3 is a construction procedure diagram according to the first embodiment of the present invention.

FIG. 4 is a sectional view showing an internal structure of a steel pipe pile according to Embodiment 2 of the present invention.

[Explanation of symbols]

 A ······················································································································· ······························································· Bottom closing member

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-8-311854 (JP, A) JP-A-6-264433 (JP, A) JP-A-2-58623 (JP, A) JP-A-59-1984 220523 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) E02D 3/10 104

Claims (2)

(57) [Claims] (1) A pipe pile having a drilling blade at the tip is set at a predetermined position, and an on- off valve is provided at the tip of the pipe pile to provide an on- off valve.
Close the pipe and press the sand under the open / close valve to form a sand plug to close the pipe pile tip side. Pipe pile setting process, and (2) press-fit the pipe pile to the depth required for liquefaction countermeasures, pile penetration Process and
(3) An appropriate amount of sand is put into the pipe pile, and the pipe pile is pulled out to an appropriate portion while rotating the pipe pile in a reverse direction to form a perforated portion. Extrude into
It consists of a sand extruding step and (4) a compacting step of compacting the sand by press-fitting the pipe pile in the forward direction. By repeating the above-mentioned sand input / extruding / compacting step, it is compacted to a predetermined portion such as the ground surface. A ground improvement method using rotating piles, characterized by forming solidified sand piles. (1) A pipe pile having a drilling blade at the tip is set at a predetermined position, and an open / close valve and a lower part are provided at the tip of the pipe pile.
Install a bottom blocking member that can be removed downward and opened and closed
A pipe pile setting process that closes the valve and closes the pipe pile tip side,
(2) Pile penetration process, in which pipe piles are pressed forward to the depth required for liquefaction countermeasures, and (3) appropriate amount of sand is injected into the pipe piles, and appropriate parts are rotated while the pipe piles are rotated in the reverse direction. Forming a perforated portion by pulling out the opening and closing valve to release the fixing between the bottom plug member and the lower end of the pipe pile, and extruding the injected sand and the bottom plug member into the perforated portion; ) A compaction step of press-fitting the pipe pile in the forward direction to compact the sand, and by repeating the above-mentioned sand injection, extrusion and compaction steps, a sand pile compacted to a predetermined site such as the ground surface is formed. A ground improvement method using a rotating pile, which is characterized in that: