JPH06257143A - Concrete composite pile - Google Patents

Abstract

PURPOSE:To easily obtain a concrete composite pile strong against compression and bending by embedding a reinforcing material made of a tapered steel pipe having a narrow tip inside of a non-hardened soil cement column, which is filled in an excavated pile hole, and solidifying the soil cement. CONSTITUTION:At the time of building a cast-in place concrete pile for the foundation of a building, before the soil cement and the mortar 13 filled in a pile hole 12 is hardened, a steel pipe 14 with taper having a narrow tip is buried, and the soft cement or the mortar 13 is solidified. The compressive force applied to the steel pipe 14 is distributed over the whole length of a cement column 13, and the partial pressure in the horizontal direction is applied. A concrete composite pile strong against compression and bending is thereby built quickly at a low cost.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a concrete composite pile, in particular, a type of cast-in-place pile used as a foundation for various buildings, which is used as a relatively small-scale friction pile or support pile.

[0002]

2. Description of the Related Art FIG. 5 is a sectional view showing a cast-in-place concrete pile, which is a type of conventional cast-in-place pile. This cast-in-place concrete pile is formed by incorporating a rebar cage 5 consisting of a vertical rebar 3 and a circumferential rebar 4 in a pile hole 2 of the ground 1, and pouring concrete 6 therein. FIG. 6 is a sectional view showing an embedded pile which is a type of conventional cast-in-place pile. This embedded pile puts mortar 7 in the pile hole 2 of the ground 1,
The concrete pile 8 with ribs is press-fitted into the mortar 7 before hardening. FIG. 7 is a sectional view showing an embedded pile which is a type of conventional cast-in-place pile. This embedded pile is formed by forming a soil cement 9 in a pile hole 2 of the ground 1 and press-fitting a ribbed steel pipe pile 10 into the soil cement 9 before hardening.

[0003]

In the conventional cast-in-place concrete pile, it takes time and effort to assemble the reinforcing bars, and the reinforcing bar cage 5 is easily deformed. Therefore, it is difficult to manage the construction to arrange the reinforcing bars in the concrete 6 at predetermined positions. There was a problem that was. Further, since the embedded pile using the conventional concrete pile 8 with ribs is a concrete pile, the weight is heavy, and a large machine is required for transportation and embedding work of the pile,
It is not suitable for work in narrow places such as densely populated houses, and has problems in terms of safety and economy. further,
In embedded piles that use ribbed steel pipe piles, the process of attaching ribs to the steel pipes is complicated, so there are restrictions on the lower limits of steel pipe sheet thickness and diameter, making it difficult to provide small-scale, simple piles at low cost. There was a problem.

The present invention has been made to solve the above problems, and has high strength, sufficient resistance against indentation, large frictional force, and lightweight steel pipe pile itself.
It is an object of the present invention to provide a concrete composite pile that can be constructed safely, quickly, and economically.

[0005]

A concrete composite pile according to the present invention is formed in the soil of the ground and has a predetermined length of a soil sensation column or a mortar column or a concrete column, and a soil sensation column before hardening. Alternatively, it is composed of a steel cement pile which is press-fitted into a mortar column or a concrete column and hardened, and is integrated with a soil cement column or a mortar column or a concrete column. Further, the sectional shape of the tapered steel pipe may be an irregular shape other than a circular shape.
Further, the tapered steel pipe may have a closed end.

[0006]

In the present invention, it is formed in the ground of the ground,
A taper that is pressed into the soil-sensing column or mortar column or concrete column of a specified length and the soil-cement column or mortar column or concrete column before hardening and is integrated with the soil-cement column or mortar column or concrete column after hardening. Since it is a concrete composite pile consisting of a steel pipe pile with a taper, the inner and outer surfaces of the steel pipe pile with a taper are constrained by a soil cement column or a mortar column or a concrete column, and the weight of the building becomes a compressive force from above. When working on a tapered steel pipe pile, since the steel pipe pile has a taper, all its compressive force is not applied to the steel pipe pile, but is distributed to the soil cement columns or mortar columns or concrete columns. Therefore, compared to steel pipe piles without taper, steel pipe piles are less likely to buckle,
Therefore, the tapered steel pipe pile can be made thin because it can be thin.

When the weight of the building acts on the soil cement column or the mortar column or the concrete column and the tapered steel pipe pile as a compressive force from above, the steel pipe pile has a taper where the tip becomes thin, The compressive force transmitted to the soil cement columns, mortar columns, or concrete columns, which are located inside and occupy the majority, is evenly applied over the entire length of the steel pipe pile, and part of the compressive force applied to the entire length of the steel pipe pile is Since it is transmitted as a horizontal component force to the soil cement column, mortar column or concrete column located outside the steel pipe pile, the soil cement column, mortar column or concrete column is against the surface in contact with the soil in the ground. It acts as a lateral earth pressure and provides sufficient frictional force between soil cement columns or mortar columns or concrete columns and the soil in the ground. Therefore, a concrete composite pile having a large frictional force can be obtained.

Further, in the case where the tip of the tapered steel pipe is closed, a sufficient supporting proof strength can be obtained at the tip, so that it can be used as a support pile.

[0009]

1 is a sectional view showing an embodiment of the present invention, FIG.
FIG. 3 is a cross-sectional view taken along the line AA of FIG. 1, and FIG. 3 is an explanatory view for ensuring the frictional force between the ground and the concrete composite pile against the pushing force. In the figure, 11 is the ground, 12 is a diameter of 200-
400 mm, depth 5 to 13 m pile hole, 13 is a soil cement column formed in the pile hole 12 pre-drilled in the ground 11,
14 has a plate thickness of 3 to 4.5 mm, a length of 4 to 9 m, and a front end of 150 to
300mm, end opening 80-150mm (taper ratio 1 / 60-1 / 100)
It is a steel pipe pile with a taper that gradually becomes thinner toward the tip of the. Reference numeral 15 is a foundation formed of concrete or iron plate or the like provided at the main opening which is the base end of the tapered steel pipe pile 14, and 16 is a building foundation installed on the foundation 15.

The soil cement composite pile of this embodiment is constructed as follows. At a predetermined drilling position on the ground 11, excavating and excavating the cement milk injection amount by an auger or the like to form a pile hole 12, then excavating and stirring the ground 11 while injecting cement milk, Soil sensation pillar 13 is created. Then, the tapered steel pipe pile 14 is built in the soil cement pillar 13 before the soil cement is still set, and the soil cement is hardened to complete the concrete composite pile of the soil cement pillar 13 and the tapered steel pipe pile 14.

The concrete composite pile constructed as described above is pressed into the soil cement column 13 formed in the ground of the ground 11 and the soil cement column 13 before hardening, and the soil cement after hardening is cemented. It is composed of the pillars 13 and the steel pipe piles 14 with a taper integrated therewith, and works as a composite structure and has a high strength. Then, the inner and outer surfaces of the tapered steel pipe pile 14 of the concrete composite pile are restrained by the soil cement columns 13, and when the weight of the building acts on the tapered steel pipe pile 13 as a compressive force from above, Since the steel pipe pile 14 has a taper, all its compressive force is not applied to the steel pipe pile 14 but is dispersed to the soil cement columns 13. Therefore, buckling is less likely to occur as compared with the conventional vertically-installed ribbed steel pipe pile having no taper, and the tapered steel pipe pile 14 can have a thin plate thickness, and thus can be lightened.

Further, this does not require handling of heavy objects like the conventional ribbed concrete pile 8 and brings about safety, quickness and economy of construction. Further, since the tapered steel pipe pile 14 may have a thin plate thickness, it can be mass-produced easily from a general thin-plate hot-rolled coil in a factory without using special dedicated equipment and has a shape. Simple substance
Because it is simple, the shape is stable and no special on-site processing is required. Further, since the tapered steel pipe pile 14 has a taper after manufacturing in the factory, it can be transported while being inserted with the other one inside, which is convenient. Furthermore, since the tapered steel pipe pile 14 is embedded in the soil cement column 13, the tapered steel pipe pile 1 is surrounded by an alkaline atmosphere such as soil cement.
4 has an advantage that it is protected from oxidation due to air and soil components, that is, it is not necessary to see the rust margin.

Further, when the weight of the building acts on the soil cement column 13 and the tapered steel pipe pile 14 as a compressive force from above, the steel pipe pile 14 has a taper at which the tip becomes thin, so that the inside of the steel pipe pile 14 is The compressive force transmitted to the soil cement columns 13 located and occupying most of the steel pipe piles 14
Is uniformly applied over the entire length of the steel pipe pile 14, and part of the compressive force applied to the entire length of the steel pipe pile 14 is transmitted to the soil cement column 13 located outside the steel pipe pile 14 as a horizontal component force.
The soil cement pillar 13 acts as a lateral earth pressure against the surface of the soil 11 in contact with the soil, and the soil cement pillar 13
A sufficient frictional force can be obtained between the soil and the soil in the ground 11. That is, the substantial frictional force on the peripheral surface increases. Therefore, a concrete composite pile having a large frictional force can be obtained. In this way, the compressive force from the top acts on the tapered steel pipe as a tensile force in the circumferential direction, so soil cement has strong compressive force and steel material has strong tensile force. It will be saved. Further, this means that sufficient frictional force can be obtained without providing ribs that are difficult to manufacture such as the ribbed concrete pile 8 and the ribbed steel pipe pile 10 that are vertically built up as in the conventional case.

In the above embodiment, the depth of the pile hole 12 is 5 to 13 m.
However, it is needless to say that the present invention can be implemented by using the steel pipe pile 14 having a tapered length corresponding to a pile hole having a depth of 13 m or more, which is deeper than that. As shown in FIG. 3, before the BB peripheral frictional force between the soil cement column 13 and the ground 11 reaches the maximum value, AA between the tapered steel pipe pile 14 and the soil cement column 13 is reached. Taper ratio of steel pipe pile 14 and soil cement column 1 so that slip does not occur
It is necessary to set the strength of 3. Although the soil cement column 13 is described as the concrete column in the above-mentioned embodiment, the same action and effect as the soil cement column 13 can be obtained regardless of whether it is a mortar column or a normal concrete column. Needless to say.

FIG. 4 is a sectional view showing another embodiment of the present invention. In this example, a tapered steel pipe pile 24 with a closed tip is used, and a tapered steel pipe pile 24 with a closed tip and a length corresponding to a pile hole 12 having a depth of 20 m is used. Show. Other configurations are similar to those shown in FIG. In this embodiment, since the tip end of the tapered steel pipe pile 24 is closed, the supporting proof strength is increased at the tip, which is particularly useful when used as a support pile. Although the tapered steel pipe piles 14 and 24 of any of the above-mentioned examples have a circular cross-sectional shape, it is said that the present invention can be implemented even if they have other elliptical shapes or polygonal irregular shapes. There is no end.

[0016]

Industrial Applicability As described above, the present invention is formed in the soil of the ground and has a predetermined length of soil senment columns or mortar columns or concrete columns and unhardened soil senment columns or mortar columns or concrete. Since it is a concrete composite pile consisting of a hardened soil cement column or mortar column or a concrete column and a tapered steel pipe pile that is integrated into the column after being hardened, the tapered steel pipe pile has soil cement columns or mortar on its inner and outer surfaces. When the weight of the building acts on the tapered steel pipe pile as a compressive force from above, the steel pipe pile has a taper, so the compressive force is not applied to the steel pipe pile. Since it is also dispersed in soil cement columns, mortar columns or concrete columns, steel pipe piles may buckle. Is reduced, correspondingly tapered steel pipe pile can weight reduction because a good thin thickness, has the effect that the safety of construction, rapidity, economy results.

When the weight of the building acts as a compressive force from above on a soil cement column or mortar column or a concrete column and a steel pipe pile with a taper, the steel pipe pile has a taper where the tip becomes thin, The compressive force transmitted to the soil cement columns, mortar columns, or concrete columns, which are located inside and occupy the majority, is evenly applied over the entire length of the steel pipe pile, and part of the compressive force applied to the entire length of the steel pipe pile is Since it is transmitted as a horizontal component force to the soil cement column, mortar column or concrete column located outside the steel pipe pile, the soil cement column, mortar column or concrete column is against the surface in contact with the soil in the ground. It acts as a lateral earth pressure and provides sufficient frictional force between soil cement columns or mortar columns or concrete columns and soil in the ground, Has the effect of large concrete composite piles force can be easily obtained.

Further, since the tip end of the tapered steel pipe pile 24 is closed, the supporting proof strength is increased at the tip end, so that it is also useful as a support pile.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is an explanatory diagram for securing a frictional force between the ground and a concrete composite pile against a pushing force.

FIG. 4 is a sectional view showing another embodiment of the present invention.

FIG. 5 is a sectional view showing a cast-in-place concrete pile, which is a type of conventional cast-in-place pile.

FIG. 6 is a cross-sectional view showing an embedded pile which is a type of conventional cast-in-place pile.

FIG. 7 is a cross-sectional view showing a buried pile, which is a type of conventional cast-in-place pile.

[Explanation of symbols]

 11 Ground 13 Soil cement column 14 Tapered steel pipe pile

Claims (3)

[Claims] 1. A soil senment column or mortar column or concrete column having a predetermined length, which is formed in the ground of the ground, and a soil senment column, mortar column or concrete column before hardening, is press-fitted and then hardened. 2. A concrete composite pile, comprising: a soil cement column, a mortar column, or a concrete column and a tapered steel pipe pile. 2. The concrete composite pile according to claim 1, wherein the tapered steel pipe has an irregular shape other than a circular shape. 3. The concrete composite pile according to claim 1, wherein the tip of the tapered steel pipe is closed.