JPH0447236Y2 - - Google Patents

Description

[Detailed description of the invention] <Technical field> This invention relates to embedded piles, which are used by being embedded in pile holes that are drilled and formed in the ground in advance when constructing foundations for various buildings and structures.

<Prior art> When the ground on which the foundation of the above-mentioned building is being constructed does not have a suitable hard support layer, the so-called friction pile construction method, in which the foundation pile is supported by the frictional bearing force with the ground, is adopted. ing. When using prefabricated piles in the above-mentioned friction pile construction method, in order to avoid causing environmental pollution due to the negative impact of vibration and shock on the surrounding environment, it is necessary to use the embedded pile method instead of the driving method in which the piles are driven directly into the ground. Construction by
It has been adopted as a suitable low-pollution construction method.

In addition, in the above-mentioned friction pile construction method, the pile bearing capacity is expressed by the frictional force between the ground and the surrounding surface of the pile, so compared to the conventional driving method, the pile's own weight acts more as a factor in reducing the bearing capacity. do. Therefore, it is preferable to use lightweight piles made of steel pipes, lightweight concrete, etc. as embedded piles.

Furthermore, in the friction pile construction method, sufficient frictional force cannot be exerted unless the pile hole and the pile circumferential surface are in close contact with each other. Therefore, a pile fixative such as cement milk is injected between the pile circumferential surface and the hole wall to fill the gap between the pile circumferential surface and the hole wall, and as this fixative solidifies, the pile is fixed. A construction method is used to securely fix it in a pile hole. As the above-mentioned fixing liquid, even if groundwater is present in the pile hole, a liquid with a much heavier specific gravity than groundwater is used in order to ensure that it surrounds the pile and exists stably. Ru.

However, when the above-mentioned lightweight pile and fixative solution are used in combination, the lightweight pile is suspended due to the large buoyancy of the fixative solution, which has a high specific gravity, until the fixative solution injected around the pile is completely solidified. There is a problem in that the piles lift up from the bottom of the hole, making it impossible to install them as embedded piles.In the past, it was difficult and impractical to use a lightweight pile and a fixative at the same time.

<Purpose> Therefore, the purpose of this invention is to solve the problems of the conventional technology described above, and to create a buried pile that does not lift up due to the fixing fluid and can exert reliable frictional support even if it is a lightweight pile. The purpose is to provide a stake.

<Configuration> In order to achieve the above objective, in an embedded pile that is used by being embedded in a pile hole drilled in the ground, a lifting prevention protrusion is formed near the top of the peripheral surface of the pile, and a protrusion is formed to prevent lifting from the center of the pile. It is characterized in that the length to the tip of the projection is longer than the length from the center of the pile hole to the hole wall.

<Example> Next, an example of this invention will be described below with reference to the drawings.

As shown in Figures 1 to 3, 1 indicates the entire embedded pile, which is manufactured by molding from lightweight concrete such as concrete mixed with lightweight aggregate or aerated concrete. It has a cylindrical shape similar to a pile. Reference numeral 10 denotes lifting prevention protrusions, each having a thin circular bar shape and protruding horizontally and symmetrically outward at two diametrically opposed locations near the upper end of the peripheral surface of the pile 1. It has been done. In the case of the embedded pile 1 of this invention, the length from the center to the tip of the uplift prevention protrusion 10 is made larger than the length from the center to the hole wall of the pile hole formed in the ground, which will be described later. shall be taken as a thing.

To explain the construction process of the above-mentioned embedded pile 1, a pile hole 20 is previously excavated in the ground 2 using a pole-erecting truck, an earth auger, etc., and the pile 1 is embedded in this pile hole 20. The hole diameter of the pile hole 20 is the same as that of the pile 1.
The inside diameter of the hole is approximately the same as the outside diameter of the hole.
The inner diameter of the pile 0 is slightly larger than the outer diameter of the pile 1. Therefore, there will be a slight gap between the pile hole 20 and the circumferential surface of the pile 1. Therefore,
In order to fill the above-mentioned gap, a fixing liquid 3 such as cement milk is injected into the pile hole 20.

When embedding the pile 1 in the pile hole 20, first, a rod-shaped protrusion 10 formed near the upper end of the pile 1 and having an outer diameter protruding from the pile hole 20 is pushed into the ground 2 around the pile hole 20. While doing so, lower the pile 1 vertically and embed it to the top of the pile 1. In this state, the protrusion 10 displaces the ground 2 in the vertical direction and is embedded while forming the vertical exclusion groove 21. Therefore, if it passes through the vertical exclusion groove 21 in the reverse direction, it will pass through the vertical exclusion groove 21 with almost no resistance. It can be moved back upwards, and if it remains as it is, there will be no lifting prevention effect.

After that, when the pile 1 is twisted horizontally and rotated by a certain angle, the protrusion 10 of the pile 1 will move into the third position in the ground 2.
Turning from the figure to the state shown in Figure 3, the ground 2
It bites into the ground 2 and is locked while forming a horizontal exclusion groove 22 inside. In this state, pile 1
The protrusion 10 bites into the ground 2 in the horizontal direction, so even if a force is applied to lift the pile 1 upward due to the buoyant force of the fixing liquid 3, the protrusion 10 bites into the ground 2, Prevents movement in the vertical direction and reliably prevents lifting.

As described above, embed the stake 1 and the protrusion 10
Then, if the fixing solution is completely solidified by leaving it for a certain period of time in a state where it is securely hooked to the ground 2, the construction of the embedded pile 1 is completed. Note that the fixing liquid 3 or the surrounding soft ground 2 flows into the exclusion grooves 21 and 22 formed in the ground 2 by the projections 10 and blocks them, so after construction, the entire circumferential surface of the pile 1 is is embedded in close contact with the ground 2.

Of the embedded piles 1 described above, the uplift prevention protrusion 10 may have a shape that is easy to push into the ground 2 and can be securely locked, in addition to the cylindrical bar shape shown in the figure, a square bar shape or a multi-shaped shape. Square rod-shaped ones, or as shown in Figure 4, vertical plate-shaped ones, horizontal plate-shaped ones,
It can be implemented in any suitable shape, such as a spherical mountain shape. Furthermore, it is easy to manufacture the protrusion 10 by protruding horizontally in the radial direction with respect to the vertical pile 1.
If the protrusion 10 is formed so as to protrude slightly upward from the horizontal direction, it will strongly bite into the ground 2 due to the force of lifting after embedding, so lifting can be more reliably prevented. . Furthermore, if the protrusion 10 is formed to protrude in a direction oblique to the radial direction, resistance may be reduced when the stake 1 is embedded and rotated in the horizontal direction.

The protrusion length of the protrusion 10 is sufficient as long as the part that bites into the ground 2 can securely lock onto the ground 2 against the buoyancy of the fixative liquid 3. If the protrusion 10 protrudes too long, resistance during embedding may occur. is large and easily deformed in terms of strength, which is not preferable.

Next, the protrusion 10 can be formed at any position on the circumferential surface of the pile 1, but as shown in the figure, the protrusion 10
It is better to form the protrusion 10 near the upper end of the protrusion 1.
The distance to embed 0 into the ground 2 is reduced, and the
The resistance when embedding the entire structure can be reduced, and the wall of the hole is less likely to collapse during the embedding process, which is a practically preferable implementation.

In addition, as for the number of protrusions 10 formed, even one protrusion has the effect of preventing uplifting, but in order to accurately place the stake 1 in the center of the pile hole 20 and prevent uplifting in a stable state, multiple protrusions 10 are required. Preferably, the protrusions 10 are arranged diametrically symmetrically with respect to the circumferential surface of the pile 1. Note that if the protrusions 10 are formed at a plurality of locations in the vertical direction, the effect of preventing floating will be further enhanced.

Methods for forming the protrusion 10 described above include a method in which a concave portion corresponding to the shape of the protrusion 10 is formed in the mold for the pile 1, and integral molding is carried out at the same time as the molding and manufacturing of the pile 1; is embedded in the mold of the pile 1 and integrally joined at the same time as the molding of the pile 1, the molded pile 1
The projection 10 can be formed by embedding a separately manufactured protrusion 10, or the like. The material of the protrusion 10 may vary depending on the manufacturing method described above, but it may be made of the same material as the pile 1, such as concrete, steel, wood, etc.
As long as it has enough strength to prevent the pile 1 from floating up, it can be used satisfactorily.

<Effects> According to the embedded pile 1 of this invention configured as described above, when the uplift prevention protrusion 10 is formed on the circumferential surface of the pile 1 and the pile 1 is embedded in the pile hole 20 in the ground 2, Since the uplift prevention protrusion 10 is formed so as to bite into the ground 2 and be locked,
Even if the large buoyant force of the fixing liquid 3 is applied to the pile 1 in the pile hole 20, the pile 1 will not float upward, and the pile 1 can be reliably held in a stable state until the fixing liquid 3 hardens. .

After the embedding construction, the protrusion 10 is placed in the ground 2.
Since it is completely embedded in the pile 1, it does not have a negative effect on the frictional supporting force of the pile 1, and it is possible to exhibit the same supporting force as a normal embedded pile.

In addition, by forming the protrusion 10 near the top of the pile 1, the distance to embed the protrusion 10 into the ground 2 is reduced, reducing resistance when embedding the pile 1, and causing less collapse of the hole wall during embedding work. effective.

In particular, when a lightweight pile is used as the embedded pile 1, the above-mentioned lifting prevention is very important, and the effect of the lifting prevention protrusion 10 of this invention is extremely large, and it is useful for buildings etc. It has high practical value and can greatly contribute to improving the performance of the friction pile construction method for foundation piles.

[Brief explanation of the drawing]

The figure shows an example of this invention.
2 is a sectional view of the main part in a direction orthogonal to the previous figure, FIG. 3 is a horizontal sectional view showing the construction stage, and FIG. 4 is a perspective view of a modified example of the protrusion. 1...Embedded pile, 10...Protrusion for preventing lifting, 2...Ground, 20...Pile hole, 3...Fixing liquid.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. In an embedded pile that is used by being embedded in a pile hole drilled in the ground, a protrusion to prevent lifting is formed near the upper end of the peripheral surface of the pile, and the length from the center of the pile to the tip of the protrusion is An embedded pile characterized in that the diameter is larger than the dimension from the center of the pile hole to the hole wall. 2. The embedded pile according to claim 1 of the above-mentioned utility model registration, wherein a plurality of protrusions are arranged and formed in symmetrical positions with respect to the center of the pile as the lifting-preventing protrusions. 3. The embedded pile according to claim 1 of the above-mentioned utility model registration claim, wherein the lifting-preventing protrusion is a bar-shaped protrusion.