JPH02115409A - Spiral pile and method of embedding thereof - Google Patents

Abstract

PURPOSE:To aim at enhancing the support pressure by forming a groove in a spiral flange wound around a spiral pile in the outer peripheral axis direction by a predetermined length measured from the lower end thereof, by screwing the pile into a preparation hole formed in the ground while it being normally and reversely rotated and being pulled out and inserted into, and by press-filling a filler such as mortar or the like into the hole. CONSTITUTION:Spiral flanges 2 are formed at the outer periphery of a columnar base body 1 having a sharpened forward end while the length thereof is set to a value less than two-third or the overall length H, and further, the number of the spiral flanges is set to 3 to 5. A plurality of grooves 3 are formed in the spiral flanges at every pitch at circumferentially symmetrical positions. The spiral pile is screwed into a preparation hole 4 formed by a drill having a diameter slightly larger than the outer diameter of the spiral pile, and then a filler 7 such as mortar or the like is filled under a suitable pressure while a drive shaft 5 being normally and reversely rotated and being pulled out and inserted into so as to be fed downward with the filler being rocked. With this arrangement, it is possible to increase the support pressure and to carry out the driving of the pile with no vibration and no noise, that is, no pollution.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention is a relatively small-sized device used for foundations of general houses, etc. a! It is related to turning piles.

[Conventional technology]

Conventionally, pine stakes have been used as this type of stake, but because stakes made of this material corrode, they become thin and thin after 10 years, rendering them useless as stakes. In addition, in order to drive this in, nine heavy machines were used to hit it from above, but the noise and
The vibrations were so strong that nine surrounding houses were tilted, and nearby residents complained. Furthermore, this method has the disadvantage that the impact destroys the pile itself, and that if it encounters hard rock, the pile cannot be driven straight downward.

As a solution to this problem, for example,
As seen in Japanese Patent No. 681, a spiral pile has been proposed in which a spiral collar is formed on the outer periphery of an antibody and screwed into the antibody with two forced rotational forces.

[Problem to be solved by the invention]

However, in order to screw a spiral pile directly into the soil with one rotational force, a very large load is applied to the pile (particularly the collar part), so the antibody itself is required to have strong strength. In particular, the load applied to the brim is large, and this part cannot be strengthened due to its shape, making it difficult to drive piles smoothly. Furthermore, even if the pile was successfully screwed in, the surrounding earth and sand would be discharged to the ground due to the spiral collar, which would weaken the support strength of the pile.

This invention was devised to deal with such problems, and what is its purpose?

To provide a helical pile that is easy to drive and has strong bearing capacity.

[Means to solve the problem]

That is, the present invention provides a GL pile having a spiral flange on the outer periphery, in which a groove extending in the axial direction is formed on the outer periphery of the spiral flange, and the length of the spiral flange portion is reduced to 2/3 or less from the lower end. A spiral pile that is set.

A spiral pile has a plurality of grooves formed at symmetrical positions on the circumference between one pitch of the spiral collar.

In the soil II! &17i? ! Drill a pilot hole with a diameter that is equal to or slightly larger than the outer circumference of the pile, screw the helical pile into it by rotating it forward and backward and inserting and removing it up and down, and then press-fit a filler such as cement milk or mortar from above to fill the filler. A method for burying a helical pile by filling the lower part and surrounding area of the helical pile with high density.

are provided respectively.

[Effect]

With the helical pile configured as described above, the earth and sand during driving is discharged upward from the groove on the outer periphery of the helical flange, so that the earth and sand can be easily discharged and the load applied to the helical flange is reduced. In addition, the length of the spiral tsuba is set to less than 2/3 from the bottom, and the upper part is a simple cylinder, so the earth and sand discharged by the spiral tsuba does not rise to the ground, but stays on the outer periphery of the pile. , the drop in support pressure is also small. Furthermore, according to this burying method, since the pilot hole is drilled and then the spiral pile is screwed in, the force required for screwing in the pile is small, and vibration and noise can also be reduced. Furthermore, since the helical pile itself is screwed in while being rotated forward and backward and inserted and removed up and down, it is possible to fill the filling material with high density.

〔Example〕

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

Figure 1 is a side view of this spiral pile, Figure 2 is the main part (spiral guard)
The enlarged side view of FIG. 3 is also a plan view.

This +! ! ! The rotary pile is formed of concrete containing reinforcement reinforcing bars as appropriate, and its shape is such that a spiral collar 2 is formed on the outer periphery of a cylindrical base body 1 with a pointed tip. Note that the reinforcing reinforcing bars are not limited to the first part of the base body, but are also enclosed in the second part of the spiral collar.

By the way, the length h of the part where the swivel tsuba 2 is formed is set to 2/3 or less from the bottom of the total length H of the pile, and the number of the parts is also 3.
It is about 5. In this way, the reason why the spiral tsuba 2 is not formed over the entire length of the pile is because when the pile is screwed in, the surrounding earth and sand will not be discharged to the ground (if it is discharged, the supporting pressure will be weak). Furthermore, the reason why the length was set to 2/3 was that this length was found to be appropriate as a result of testing. Of course, doing so has the effect of reducing the manufacturing cost of the pile. Next, a groove 3 extending in the axial direction is formed on the outer periphery of this spiral collar 2. This groove 3 is I! l! Turn tsuba 2
Multiple pieces are formed at symmetrical positions on the circumference during one pitch of (
In this example, two are shown, but the invention is not limited to this). Furthermore, although it is suitable for manufacturing that 1ji3 be formed in a straight line over the entire length of the rotating tsuba 2, the position (phase) may be changed for each pitch.

The above spiral pile may be screwed into the soil as is, but it can be buried even more firmly if driven using the following method.

Fig. 4 is a cross-sectional view showing this condition. In advance, a pilot hole 4 is drilled at the location where the pile is to be driven using a drill (auger) with a diameter equal to or slightly larger than the outer circumference of the a' pivot pile. , A spiral pile is screwed into this prepared hole 4. Incidentally, the screwing of the helical pile at this time is carried out by attaching an attachment 6 that can engage with the upper end of the helical pile to the drive shaft 5 of one heavy machine using the power of the heavy machine that drove the drill. Then, when screwing in, filler material 7 made of cement milk, mortar, etc. is appropriately press-fitted (in this case, a hopper 8 is used at the above-ground injection port to prevent the ground from loosening). By the way, at the time of press-fitting, if the drive shaft 5 is rotated forward and backward as appropriate, and inserted and removed up and down, the injected filler 7 can be sent downward while being shaken up and down, which is highly effective. On the other hand, Spiral 2
Since the pile is not formed to the top of the pile, the earth and sand removed by the spiral top 2 does not rise to the ground, but mixes with the injected filler 7 and is forced downward, increasing the filling density. Furthermore, the above-mentioned groove 3 is provided on the outer periphery of the spiral top 2.
is provided, so that the filler material 7 flows down through this 83, making it easier to feed it downward. In the end, these effects work together, and the injected filler 7 is filled downward in a dense and lumpy manner, creating a strong support pressure for the pile.

〔Effect of the invention〕

This invention has been described above.

The following effects can be expected.

i) Since a groove 3 extending in the axial direction is formed on the outer periphery of the helical top 2, there is a function to release earth and sand that is applied with strong pressure to the helical top 2 as it is screwed in from the groove 3, 2. Prevent excessive pressure from being applied. This groove 3 also allows the downward flow of the filler material press-fitted from above.

If) Since the spiral top 2 is set to a length of 2/3 or less from the bottom of the total length of the pile, it has the effect of preventing the discharged earth and sand generated when screwing into the pile from reaching the ground. Therefore, earth and sand will still accumulate around the pile, increasing the bearing pressure.

iii) When burying this spiral pile, use the above-mentioned method of drilling a pilot hole 4 in the soil in advance, screwing the pile in while rotating it forward and backward, inserting and removing it up and down, and press-fitting the filler material 7 from above. For example, it is possible to efficiently push the filler 7 downward and fill it in the vicinity of the lower end with high density and in the form of a block, thereby generating a strong supporting pressure. And at this time, spiral top 2
The presence of the groove 3 on the outer periphery further promotes this effect.

iv) Furthermore, according to the above method, since a large force is not required to screw in the a' pivot pile, the drive shaft 5 may have a small output, and vibration-free and noise-free driving is possible. It does not cause problems such as pollution.

[Brief explanation of the drawing]

Figure 1 is a side view of this spiral pile, Figure 2 is the main part (on the spiral)
Fig. 3 is an enlarged side view, and Fig. 3 is a plan view as well. FIG. 4 is a sectional view showing this method of burying the pile. (Code) 2...l1lI turning tsuba 3...groove 4...prepared hole 7...Filling material agent Patent attorney Yoshi Itano

Claims (1)

[Claims] [1] In a spiral pile having a spiral collar (2) on the outer periphery,
A spiral pile in which a groove (3) extending in the axial direction is formed on the outer periphery of the spiral collar (2), and the length of the spiral collar (2) is set to 2/3 or less from the lower end. [2] The spiral pile according to claim [1], wherein a plurality of grooves (3) are formed at symmetrical positions on the circumference between one pitch of the spiral collar (2). [3] Drill a pilot hole (4) in the soil with a diameter equal to or slightly larger than the outer circumference of the helical pile, screw the helical pile into it by rotating it forward and backward and inserting and removing it up and down, and pour cement milk, mortar, etc. from above. A method for burying a helical pile by press-fitting a filler material (7) and filling the lower part and surrounding area of the helical pile with this filler material (7) at high density.