JPH0694658B2 - How to bury a spiral pile - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for burying a relatively small spiral pile used for the foundation of a general house or the like.

[Conventional technology]

Conventionally, a method of hitting a wooden pile, a concrete pile, a steel pipe pile, etc. by hitting with a heavy machine has been used for burying foundation piles for general houses, etc. There was a problem that the impact itself would destroy the pile itself.
For this reason, recently, there has been proposed a method of using a spiral pile in which a spiral collar is formed on the outer periphery of the pile, and screwing this into the soil by the forced rotating force of a heavy machine (for example, Jikho Sho 47-29681). ).

[Problems to be Solved by the Invention]

However, in order to screw the spiral pile directly into the soil by the rotating force, a very large load is applied to the pile (particularly the flange portion), and thus the antibody itself is required to have a high strength. In particular, a large load is applied to the flange portion, and this portion cannot be structurally increased in strength, so smooth burying was difficult. Further, even if the pile can be safely screwed in, the surrounding earth and sand are discharged to the ground by the spiral brim, so that the supporting strength of the pile is weakened.

The present invention has been devised in order to address such a problem, and its intended purpose is easy implantation,
Moreover, it is to provide a method for burying a spiral pile having a strong supporting force.

[Means for Solving the Problems]

That is, the present invention is a method of burying a concrete spiral pile in which a spiral flange is formed below the lower part 2/3 while leaving a straight cylindrical portion in the upper part, and a V groove is provided on the outer periphery of the spiral flange, and the spiral pile is previously spirally wound by an auger Drill a pilot hole with a diameter slightly larger than the outside diameter of the pile, screw the spiral pile into the pilot hole, and put a filler such as cement milk or mortar around the spiral pile from the upper end of the pilot hole on the ground surface. It is characterized in that the spiral pile is buried by rotating the spiral pile forward and backward and inserting and removing it up and down to send the filling material to and fill the lower part and the periphery of the spiral pile.

[Action]

According to the embedding method of the present invention, the spiral pile is screwed into the soil after preparing a prepared hole having a diameter that is equal to or slightly larger than the outer diameter of the spiral pile in advance, so that the rotational force for screwing is small. Moreover, the load applied to the spiral pile is small, and there is little vibration and noise. or,
Since the filler is put around the spiral pile from the upper end of the prepared hole on the ground surface while rotating the concrete spiral pile forward and backward and vertically inserting and removing, the filler is the normal and reverse rotation of the spiral pile and the vertical inserting and removing movement. It mixes with the earth and sand and is sent to the lower part and the circumference of the spiral pile, and it is packed with high density. Furthermore, the concrete spiral pile used in the present invention is one in which a spiral flange is provided below the lower 2/3 while leaving a straight cylindrical portion in the upper part, so that the filler and earth and sand removed by the spiral flange. The mixture does not rise to the ground and stays on the periphery of the pile and does not reduce bearing capacity. In addition, since a V groove is provided on the outer circumference of the spiral collar, moisture and gas generated by the hydration reaction of the filler are released from this groove to enhance the filling effect and to temporarily increase the excessive load on the spiral collar. Alleviate the impact.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a side view of a spiral pile used in the present invention, FIG. 2 is an enlarged side view of a main part (spiral collar), and FIG. 3 is the same plan view.

This spiral pile is made of concrete in which reinforcement bars are appropriately enclosed, and its shape is a cylindrical base body 1 with a pointed tip.
A spiral collar 2 is formed on the outer periphery of the. In addition, the reinforcing bar is not limited to the base body 1 portion but is also enclosed in the spiral brim 2 portion.

The spiral collar 2 is formed below the pile, and the upper portion is left as a right cylindrical portion. The length h of the portion where the spiral collar 2 is formed is set to 2/3 or less from the bottom with respect to the total length H of the pile, and the number is 3 to
About 5 is preferable. Thus, the reason why the spiral collar 2 is not formed over the entire length of the pile is that when the pile is screwed in, the mixture of the surrounding filler and earth and sand is not discharged to the ground (if it is discharged, , The supporting power becomes weaker), and that the length is preferably up to 2/3, the test result shows that
Because this place is appropriate. Of course, this also has the effect of reducing the manufacturing cost of the pile. Next, the V-grooves 3 extending in the axial direction are formed on the outer periphery of the spiral flange 2 at appropriate intervals. A plurality of the V-grooves 3 are formed at circumferentially symmetrical positions within one pitch of the spiral flange 2 (two grooves are shown in this example, but the number is not limited thereto). Further, the V groove 3 is preferably formed in a straight line over the entire length of the spiral collar 2 in manufacturing, but the position (phase) may be changed at each pitch.

The above spiral pile is buried in the soil by the method shown in FIG. First, the prepared hole 4 is previously drilled in a place where the pile is to be hit with a drill (auger) having a diameter equal to or slightly larger than the outer diameter of the spiral pile. Next, a spiral pile is screwed into the prepared hole 4. This screwing is performed by using the power of the heavy machine that drives the drill, and attaching the attachment 6 that can be engaged with the upper end of the spiral pile to the drive shaft 5 of the heavy machine. By the way, at the time of this screw-in, a hopper 8 is provided from the upper end of the prepared hole 4 on the surface of the earth so that the filler 7 made of cement milk, mortar or the like is appropriately inserted. The term "filler" used here means
It is a mixture of the soil discharged when the pilot hole 4 is drilled and the cement-based ground reinforcement, and when this is put into the pilot hole 4 in the powder state, the water content in the pilot hole 4 It means that it becomes a fluid such as the above-mentioned mortar when mixed with sand or sand. And
At the time of this injection, the drive shaft 5 is driven to appropriately rotate the spiral pile in the normal and reverse directions and to pull it up and down. As a result, the injected filler 7 is agitated and mixed while being shaken up and down, and is forcibly fed downward, and the effect of filling the lower part and the periphery of the spiral pile is high. By performing such an operation, the filling condition of the filling material can be grasped well, and when it is not enough, it is possible to pull out the spiral pile upward and inject the filling material again. On the other hand, since the spiral collar 2 formed in the spiral pile used here is not formed up to the upper end of the pile, the earth and sand removed by the spiral collar 2 and the filler 7 injected without rising to the ground. It is mixed and forcedly fed downward to increase the packing density. In addition, since the above-mentioned V groove 3 is provided on the outer periphery of the spiral collar 2, moisture, gas or the like emitted from the filler 7 escapes upward from this, and the filling effect of the filler is enhanced. After all, these effects synergize with each other, and the filled filler 7 is packed in the lower part and the periphery of the spiral pile with a high density, and in the lower part in a lump form, and these have a strong supporting force for the spiral pile. It is generated.

〔The invention's effect〕

As described above, since the present invention is as described above, the following effects can be expected.

i) Since the spiral pile is preliminarily drilled in the soil with a pilot hole having a diameter slightly larger than that of the spiral pile and then screwed into this pilot hole, the spiral pile is buried without the pilot hole. The load on the spiral pile is reduced compared to the method. Therefore, as this spiral pile, an inexpensive concrete pile reinforced with a reinforcing bar or the like can be used, and it is also possible to further increase the amount of protrusion of the spiral collar and further strengthen the supporting force. Of course, needless to say, the output of the heavy equipment required for driving is also small, and burying at low cost is possible.

ii) Since the spiral collar is rotated in the normal and reverse directions, inserted and removed vertically, and screwed in, and the filler is inserted from the periphery of the spiral pile on the surface,
It is possible to effectively feed the filler downward, and to densely fill the lower part and the periphery of the spiral pile with earth and sand. Especially near the lower end of the spiral pile, with high density,
It can be packed in chunks, which generate a strong bearing capacity.

iii) Since the spiral brim is provided only below the lower part 2/3 of the pile, it has the effect of not discharging discharged earth and sand generated during screwing to the surface. Therefore, earth and sand still accumulate around the pile,
This is mixed with the filler to increase the bearing capacity of the spiral pile.

iv) Since the V-groove is provided on the outer periphery of the spiral pile, moisture and gas emitted from the filler are released from the V-groove to enhance the filling effect and reduce the pressure applied to the spiral collar.

[Brief description of drawings]

FIG. 1 is a side view of a spiral pile used in the present invention, FIG. 2 is an enlarged side view of a main part (spiral collar), and FIG. 3 is a plan view of the same.
FIG. 4 is a sectional view showing a method of burying the pile. (Code) 2 ... Spiral collar 3 ... V groove 4 ... Prepared hole 7 ... Filling material

Claims (1)

[Claims] 1. A method for burying a concrete spiral pile in which a spiral flange is formed below the lower part 2/3 while leaving a straight cylindrical portion in the upper part, and a V groove is provided on the outer periphery of the spiral flange. Drill a pilot hole with a diameter that is slightly larger than the outer diameter of
While screwing the spiral pile into the pilot hole, put a filler such as cement milk and mortar around the spiral pile from the upper end of the pilot hole on the surface of the earth, and rotate the spiral pile forward and backward as well as pull it out vertically to insert the filler into the spiral pile. A method for burying a spiral pile, which comprises burying the spiral pile by sending it to and filling the lower part and the periphery of the spiral pile.