JPH0960463A - Drilling shaft and construction method for reinforced pile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To construct a bulb by setting the center of a drilling shaft held with the axis by a hollow pile concentrically with the center of the hollow pile and capable of drilling a bulb larger in diameter than the outer diameter of the hollow pile coincident with the center of the hollow pile via the injection of a solidifying material at a low pressure with the drilling shaft in this construction method for a reinforced pile forming a reinforcing core made of a reinforcing material slurried with the displaced or drilled soil and the solidifying material in the internal space of the hollow pile buried in the ground and constructing the bulb integrally with the reinforcing core at a root section. SOLUTION: This drilling shaft (a) is constituted of an offcentering preventing device 1, stirring blades 2, and drilling blades 3 having injection ports. Pawls 4 inclined with the lower ends to the outer periphery side at the desired angle are suspended rockably to the inside and outside of the drilling blades 3 at the tip sections of the drilling blades 3. For constructing a reinforced pile, the pawls 4 expand and drill a root section concentrically with the center of a hollow pile 7 via the offcentering preventing device 1, a solidifying material 10 is injected at a low pressure, and the drilled soil 11 and the solidifying material 10 are slurried by the stirring of the drilling blades 3 without giving unnecessary disturbance to a reinforcing core 13, and a bulb can be constructed concentrically with the reinforcing core 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an excavating shaft used for constructing a reinforcement pile for holding a foundation ground and a construction method for constructing the reinforcement pile.

[0002]

2. Description of the Related Art Hollow piles are filled with a reinforcing material which is a slurry of discharged soil or residual soil and a solidifying material to form a reinforcing core, and the reinforcing material is sprayed on the bottom to build a bulb integrally with the reinforcing core. As a method of constructing a strengthening pile,
Although it has the prior art No. 07905, in the case where the hollow pile is short, there is an inherent defect that the reinforcing material for high-pressure injection is ejected from the upper end of the hollow pile without being directed to the construction of the bulb. Is. Further, in the method of constructing a hollow pile on the bulb after constructing a bulb having a diameter larger than the outer diameter of the hollow pile to be buried, it is difficult to match the center of the hollow pile to be buried with the center of the bulb. is there.

[0003]

In view of the above, the present invention has been made.
In the inner space of the hollow pile to be buried in the ground, to form a reinforcement core by a reinforcement material that is a slurry of discharged soil or excavated soil and a solidifying material,
In a method of constructing a reinforcement pile in which a bulb is built integrally with the reinforcement core in a root portion, in the hollow pile, an axis thereof is held in the hollow pile and an excavation shaft capable of excavating the root portion of the bulb concentrically with the center of the hollow pile; It is intended to provide a method for constructing a reinforcing pile in which the center of a hollow pile and the center of the hollow pile can be made to coincide with each other by injecting a reinforcing material at a low pressure using a shaft to construct a bulb.

[0004]

The excavation shaft of the first aspect of the present invention is an excavation shaft comprising a center deviation prevention device, a stirring blade and an excavation blade having an injection port. A claw whose lower end is inclined as required is vertically oscillated vertically inside and outside the excavation blade.

In the method for constructing the reinforcing pile of the second invention, the excavation shaft including the center deviation prevention device, the stirring blade and the excavation blade having the injection port is inserted into the inner space of the hollow pile buried in the ground, A reinforcement pile formed by injecting a slurry-like reinforcement material of soil and a solidifying material to build a bulb at the lower end of a hollow pile, and stir-filling the reinforcement material sequentially from the bottom to the top to form a reinforcement core. In the construction method of No. 3, the excavation shaft comprises the excavation shaft of the first invention.

According to a third aspect of the present invention, there is provided a method for constructing a strengthening pile in which a reinforcing core made of a slurry-like strengthening material of excavated soil and a solidifying material is formed in the ground in a cylindrical shape having a diameter larger than the outer diameter of the hollow pile. To
The hollow pile is buried, and the reinforcing material is stirred and homogenized while inserting a drilling shaft composed of a center deviation prevention device, a stirring blade and a drilling blade having an injection port inside the hollow pile, and the lower end of the hollow pile. In the construction method of the strengthening pile in which the solidified material pumped from above the ground is injected to construct the bulb by the excavation blade, the excavation shaft comprises the excavation shaft of the first invention.

[0007]

[Operation] The center of the excavation shaft is held in the hollow pile by the center deviation prevention device, and the center of the root excavated to a diameter larger than the outer diameter of the hollow pile by the claws provided on the excavation blade is the center of the hollow pile. If the expansion of the root is due to the excavation of the claw, the injection pressure of the augment is low.

[0008]

EXAMPLES The present invention will be described with reference to Examples.
In the excavation shaft composed of the center deviation prevention device 1, the stirring blade 2, and the excavation blade 3, as shown in FIGS. 1 and 2,
On the upper surface of the inclined surface of the tip portion, a claw 4 is vertically oscillated vertically inside and outside the wing tip, and the lower end of the claw 4 is tilted toward the outer peripheral side to a required posture, and the posture is maintained inward. Stopper 5
And is positioned at a position where it abuts against the head of the vertical claw 6 with respect to the outside. Therefore, when the bulb 8 is built at the root of the hollow pile 7, when the excavation blade 3 concentric with the center of the hollow pile 7 is pushed down by the center deviation prevention device 1 and the excavation pressure is applied to the claw 4, The claw 4 opens to the outer peripheral side and can be excavated to have a diameter larger than the outer diameter of the hollow pile 7, and the claw 4 comes into contact with the inner peripheral surface of the hollow pile 7 at the time of extraction, and the claw 4 rotates inward by the extraction force. However, it is guided to the inner peripheral surface without any trouble.

Next, the construction of the reinforcement pile A will be described.
As shown in FIG. 3, when the excavation axis a is inserted into the hollow pile 7 buried in the ground by the conventional method, and then the excavation a is excavated from the lower end of the hollow pile 7 while rotating, the excavation blade 3 The claw 4 opens concentrically with the center of the hollow pile 7 on the outer peripheral side, excavates to a diameter larger than the outer diameter of the hollow pile 7, and at the same time ejects the solidifying material 10 that adheres and reacts with the soil from the injection port 9 at low pressure. Soil 11 and solidifying material 10 are mixed by stirring to form a slurry, and the required bulb 8
And then slowly pull it up with stirring to add 8 bulbs.
From the top to the top, the reinforcing material in which the soil 12 and the solidifying material 10 are slurried is injected from the injection port 9, and the reinforcing material is sequentially agitated and filled toward the upper part, as shown in FIG. The reinforcement core 13 is formed inside 7 to construct the reinforcement pile A.

The construction of the reinforcement pile B shown in FIG. 8 will be described. As shown in FIG.
4, while excavating with an excavator (not shown) having an excavation blade 3 having a diameter larger than the outer diameter of the hollow pile 7 to be buried, the solidification material 10 is injected from the injection port 9 to agitate the excavated soil 11 and the solidification material 10. The reinforcing core 13 mixed and slurried is formed into a cylindrical shape, and then the hollow pile 7 is centered on the reinforcing core 13 as shown in FIG.
Of the excavation wing 3 for rotatably inserting the excavation shaft a into the hollow pile 7 and then maintaining the axial center of the hollow pile 7 at the center of the hollow pile 7 by the center deviation prevention device 1 from the lower end of the hollow pile 7. The claws 4 excavate the root portion with a diameter larger than the outer diameter of the hollow pile 7, and at the same time, the solidified material 10 is injected from the injection port 9 at a low pressure, and as shown in FIG. 7, the excavated soil 11 and the solidified material 10 are agitated and mixed. Then, the bulb 8 is built with the augmented material that has been slurried, and then the excavation shaft a is rotated and pulled up, the reinforcing core 13 inside the hollow pile 7 is stirred, and the homogenized reinforcing core 13 is formed to form the reinforcing pile. The construction of B is completed. As described above, the bulbs 8 that are constructed integrally with the reinforcement core 13 for both the reinforcement piles A and B
Does not use fluid pressure to expand the root, maintains a constant quality without exerting unnecessary disturbance on the augment core 13, and its center is concentric with the center of the augment core 13. Therefore, high reliability can be guaranteed.

[0011]

As described above, according to the present invention, in the bulb construction in constructing the reinforcement pile, the claws of the excavating blade are held concentrically with the center of the hollow pile, so that the inner space of the hollow pile is filled. The reinforcement core and the bulb are integrally formed concentrically, and since the solidifying material is injected at a low pressure (normal pressure) when building the bulb, it does not give unnecessary disturbance to the reinforcement core and is stable in quality and highly reliable. There is an effect that can provide a degree of strengthening pile.

[Brief description of drawings]

FIG. 1 is an explanatory view of an excavation shaft a according to the present invention.

FIG. 2 is a view as seen from an arrow P in FIG. 1;

FIG. 3 is an explanatory diagram of bulb construction in constructing the reinforcement pile A.

FIG. 4 is a vertical cross-sectional view of the reinforcement pile A.

FIG. 5 is a vertical cross-sectional view showing a state where a cylindrical reinforcing core 13 is formed in the ground.

FIG. 6 is a vertical cross-sectional view showing a state in which a hollow pile 7 is embedded in a reinforcing core 13.

FIG. 7 is an explanatory diagram of bulb construction in constructing the reinforcement pile B.

FIG. 8 is a vertical cross-sectional view of the reinforcement pile B.

[Explanation of symbols]

 1 Center gap prevention device 2 Stirring blade 3 Excavation blade 4 Claw 5 Stopper 6 Vertical claw 7 Hollow pile 8 Bulb 9 Injection port 10 Solidifying material 11 Excavation soil 12 Excavation soil 13 Reinforcement core 14 Pile construction part a Excavation axis A Reinforcement pile B Reinforcement pile Pile

Claims (3)

[Claims] 1. An excavation shaft comprising a center deviation prevention device, a stirring blade, and an excavation blade having an injection port, wherein the excavation blade has a claw at its tip end, and a claw whose lower end is inclined toward the outer peripheral side as required. An excavation shaft that is oscillated vertically inside and outside the wing. 2. An excavation shaft composed of a center deviation prevention device, a stirring blade and an excavation blade having an injection port is inserted into the internal space of a hollow pile buried in the ground to form a slurry of soil and solidified material. In the construction method of the strengthening pile, injecting the reinforcing material to build a bulb at the lower end of the hollow pile, and stir-filling the reinforcing material from the bottom to the upper part in order to form the reinforcing core, wherein the excavation axis is A method for constructing a reinforcement pile comprising the excavation shaft according to claim 1. 3. The hollow pile is embedded in a pile construction part in which a reinforcing core made of a slurry-forming reinforcing material of excavated soil and a solidifying material is formed in the ground in a cylindrical shape having a diameter larger than the outer diameter of the hollow pile, While inserting the excavation shaft having the center deviation prevention device, the stirring blade and the excavation blade inside the hollow pile, the reinforcing material is stirred and homogenized, and the solidified material pumped from the ground is injected to the lower end of the hollow pile. A method for constructing a strengthening pile, which comprises constructing a bulb with excavation blades, wherein the excavating shaft comprises the excavating shaft according to claim 1.