JP2002227191A - Steel pipe soil cement pile and its installation method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steel pipe soil cement pile for achieving economical installation and less drilled soil by eliminating the waste of a solidifying material and producing an increase in bearing power of the pile by increasing adhesion between a steel pipe and a soil cement even when using a normal steel pipe with no protrusion on the surface, and its installation method and device. SOLUTION: The steel pipe soil cement pile comprises a soil cement column 1 formed of the drilled soil and the solidifying material and the steel pipe 2 to be installed in the soil cement column 1. Soil cements 1a, 1b, 1c are filled near the outside and inside surfaces of the steel pipe 2 and at a central portion in the steel pipe 2. The soil cements 1a, 1b are richer (stronger) than the soil cement 1c in mixture.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steel pipe soil-cement pile in which a soil cement column and a steel pipe installed in the soil cement column are integrated, a construction method thereof, and a construction apparatus therefor.

[0002]

2. Description of the Related Art A steel pipe soil cement pile in which a steel pipe is laid in a soil cement column made of excavated soil at the site and a solidified material such as cement milk injected from the ground, and the two are integrated by the adhesive force of soil cement. In recent years, they have been widely constructed because of their excellent bearing capacity and seismic performance, as well as less excavated soil during construction compared to cast-in-place piles and the like.

[0005] For example, FIG. 5 shows an example of a conventional steel pipe soil cement pile, in which a steel pipe 21 having a smaller diameter is laid down in a soil cement column 20 continuously constructed to a predetermined depth in the ground. I have. The soil cement is manufactured by stirring and mixing the solidified material and the excavated soil uniformly injected into both the outside and the inside of the steel pipe 21.

As the steel pipe 21, in addition to a normal steel pipe such as a spiral steel pipe, a steel pipe having a surface protrusion having a large number of protrusions formed on an outer surface thereof is used as needed in order to increase the adhesion to soil cement. I have.

[0005] A method and an apparatus for constructing a pile of this kind are disclosed in, for example, Japanese Patent No. 2645322 and Japanese Patent No. 2887702.
Among them, as a pile construction apparatus, for example, an apparatus as shown in FIG. 6A is used.

[0006] As shown in the figure, a drill bit 23 and a drill blade 24 are respectively protruded from the tip of a rotating rod 22 penetrating the steel pipe 21, and a co-rotation preventing blade 25 and a stirring blade 26 are provided at predetermined intervals above the drill bit 23 and the stirring blade 26. Stabilizers 27 for holding the rotating rod 22 at the center of the steel pipe 21 are provided at predetermined intervals above the projections.

[0007] Further, a solid material injection port (not shown) for jetting the solidified material injected into the ground through the inside of the rotary rod 22 is formed at the tip of the rotary rod 22. In such a configuration, when constructing the pile, FIG.
As shown in (e), when the rotary rod 22 rotates, the excavation bit 23 and the excavation wing 24 rotate, thereby excavating the ground.

Further, in parallel with the excavation of the ground, a solidified material such as cement milk is injected into the excavated soil from a solidified material injection port (not shown), and the solidified material and the excavated soil rotate with the rotary rod 22. By being stirred at 26, the soil cement pillars 20 are continuously formed from the ground surface to the ground.

The steel pipe 21 is made of a soil cement column 20.
Soil cement column 20 that is not yet solidified while constructing
Gradually settled in the soil
And then settled in the soil cement column 20 before the soil cement column 20 has yet to solidify.

When the construction of the soil cement column 20 and the laying of the steel pipe 21 are completed, the rotating rod 22 is pulled up to complete the construction.

[0011]

However, in the conventional steel pipe soil cement pile, since the solidified material is uniformly injected into both the outside and the inside of the steel pipe 21, the inside of the steel pipe 21 which does not require very high strength is used. Unnecessarily solidified material is injected into the center of the slab, which not only wastes the solidified material and raises the cost, but also increases the excavated soil in proportion to the amount of solidified material used. There were challenges.

Further, the adhesive force between the steel pipe 21 and the soil cement is determined by the surface condition of the steel pipe 21 and the strength of the soil cement itself adhering to the surface of the steel pipe 21, and a normal steel pipe such as a spiral steel pipe is used as the steel pipe 21. In this case, since the surface of the steel pipe 21 is smooth, the adhesive force of the soil cement is small, and there is a problem that the soil cement column 20 and the steel pipe 21 cannot be completely integrated.

When a steel pipe with a surface projection is used as the steel pipe 21, the adhesion strength of soil cement is much higher than that of a normal steel pipe. Since they are manufactured in a dedicated manufacturing process, they are extremely expensive, and thus have a problem that the material cost increases.

Further, in any of the steel pipes, if there is an empty digging portion into which the solidifying material is not injected during the construction of the pile, the viscous soil adheres to the projection and the weld bead portion, and the peripheral surface friction as the pile is obtained. There was a possibility that the resistance might decrease. Also,
If there is a cohesive soil layer in the ground where no solidification material is injected, the cohesive soil may adhere to the inner surface of the steel pipe 21 and the effect of closing the tip of the steel pipe may be reduced.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and aims to reduce the amount of excavated soil by economical construction by eliminating waste of solidified material, and to use ordinary steel pipe having no projection on the surface. However, an object of the present invention is to provide a steel pipe soil-cement pile capable of increasing the supporting force as a pile by increasing the adhesive force between the steel pipe and the soil cement, a construction method and a construction apparatus thereof.

[0016]

As a means for solving the above problems, a steel pipe soil cement pile according to the first aspect of the present invention includes a soil cement column made of excavated soil and a solidified material and a soil cement column inside the soil cement column. It is characterized by being formed with a steel pipe to be installed and being filled with a soil cement richer than the central part inside the steel pipe near the outer and inner surfaces of the steel pipe.

According to a second aspect of the present invention, a method for constructing a steel pipe soil cement pile is to use a pile construction device, injecting a solidified material into excavated soil at the time of excavation and stirring and mixing to construct a soil cement column. When laying a steel pipe in the soil cement column and constructing a steel pipe soil cement pile, a solidifying material is injected near the outer and inner surfaces of the steel pipe.

According to a third aspect of the present invention, there is provided a method for constructing a steel pipe soil cement pile, wherein a pile construction device is used to inject a solidified material into excavated soil at the time of excavation and to mix and stir to construct a soil cement column. When laying a steel pipe in this soil cement column and constructing a steel pipe soil cement pile, the steel pipe is sunk while the solidified material is sprayed to the outside of the steel pipe, and then the solidified material is placed near the inner surface of the steel pipe. It is characterized in that the construction apparatus is lifted while spraying.

The method for constructing a steel pipe soil cement pile according to claim 4 is the method for constructing a steel pipe soil cement pile according to claim 3, wherein the solidified material is solidified toward the inner surface of the steel pipe inside the steel pipe. It is characterized by injecting material.

A construction apparatus for a steel pipe soil cement pile according to a fifth aspect of the present invention is a steel pipe soil cement pile formed of a soil cement column made of excavated soil and a solidified material and a steel pipe installed in the soil cement column. In the construction apparatus, at least a digging blade and a stirring blade are respectively protruded from a tip portion of a rotating rod penetrating the steel pipe, and solidification for injecting a solidified material near the outer and inner surfaces of the steel pipe to the digging blade or the stirring blade. A material injection port is provided.

According to a sixth aspect of the present invention, there is provided an apparatus for constructing a steel pipe soil cement pile, comprising: a steel pipe soil cement pile formed by a soil cement column made of excavated soil and a solidifying material; and a steel pipe installed in the soil cement column. An apparatus for constructing, wherein at least a digging wing and a stirring blade are respectively provided at a tip portion of a rotating rod penetrating the steel pipe, the digging wing or the stirring blade is solidified near an outer surface of the steel pipe. A solidified material injection port for injecting the material is provided, and a solidified material injection hole for injecting the solidified material toward the inner surface of the steel pipe is provided on the excavating wing or the stirring blade, or the rotating rod. It is characterized by having.

According to a seventh aspect of the present invention, in the construction apparatus for a steel pipe soil cement pile according to the fifth or sixth aspect, the excavation wing and the stirring blade are projected so as to increase and decrease the diameter, respectively. It is characterized by being provided.

In this case, the excavating blade and the stirring blade are configured such that the tip portion is rotated and folded from the center, for example, and the tip portion slides in the axial direction of the excavating blade and the stirring blade from the center, respectively. Some are configured to expand and contract.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 of the Invention Figure 1
(A), (b) shows an example of a steel pipe soil cement pile according to the present invention. In the figure, a soil cement column 1 is continuously constructed to a predetermined depth in the ground. A steel pipe 2 having a smaller diameter is laid therein.

The soil cement columns 1 are soil cements 1a, 1a formed near the outer and inner surfaces of the steel pipe 2 and in the center of the steel pipe 2 continuously in the axial direction of the steel pipe 2, respectively.
It is formed of three layers b and 1c, and has a rooted portion 1d formed at the lower end thereof.

Each of the soil cements 1a, 1b and 1c, and the root consolidation part 1d are manufactured by injecting a solidified material such as cement milk into excavated soil and mixing them with stirring. Hardening part 1
d is manufactured with a soil cement richer than the soil cement 1c.

For example, by using a solidifying material having a higher concentration of a solidifying material such as cement than that used in the soil cement 1c, the soil cement is rich in the root cemented portion 1d.

Each of the soil cements 1a and 1b is sprayed with a solidifying material from another jet port in addition to the solidifying material for producing the soil cement 1c, so that the soil cement 1a,
In 1b, in addition to the solidifying material forming the soil cement 1c, there is a solidifying material injected from another injection port.

That is, the soil cements a and 1b include:
There will be more solidified material than soil cement 1c. As described above, the soil cements a and 1b are manufactured in a richer soil cement than the soil cement 1c.

The soil cement 1b may be manufactured over the entire length of the steel pipe 2 in the axial direction, or may be partially manufactured only at necessary parts. As the steel pipe 2, for example, a normal steel pipe such as a welded spiral steel pipe having no projection on the surface or a steel pipe with a surface projection having a large number of projections on the surface is used.

As described above, the layers of the high-strength soil cements 1a and 1b in which a large amount of solidifying material is injected are formed near the outer and inner surfaces of the steel pipe 2, respectively. Even when it is used, the bond strength between the soil cement column 1 and the steel pipe 2 is significantly increased, and the bond strength between the soil cements 1a and 1b and the steel pipe 2 due to the adhesion of the viscous soil to the surface of the steel pipe 2 is increased. A steel pipe soil cement pile with minimum deterioration is formed.

Embodiment 2 of the Invention FIG. 2 (a), (b)
Fig. 1 shows an apparatus for constructing a steel pipe soil cement pile according to the present invention. As shown in the figure, a leading drill bit 4, a drilling wing 5, a co-rotation preventing wing is provided at a tip portion of a rotating rod 3 which penetrates a steel pipe 2 and rotates by power. 6 and stirring blades 7 are protruded from the bottom in order from the top at predetermined intervals.

A rotating rod 3 is provided above these wings.
(Not shown) for holding the center of the steel pipe 2 at a predetermined interval. The preceding drill bit 4 and the drilling wing 5 rotate with the rotary rod 3 to drill the ground, and the stirring blade 7 rotates with the rotary rod 3 to mix the excavated soil and the solidified material.
Furthermore, the co-rotation prevention blade 6 prevents the so-called “co-rotation phenomenon” in which the excavated soil is stationary in the ground and the excavated soil rotates together with the excavation blade 5 and the stirring blade 7. It protrudes horizontally relative to the sides or in three or four directions.

In particular, the excavation blade 5, the co-rotation prevention blade 6 and the stirring blade 7 are all located at the tip portions 5a, 6a from the center.
And 7a can be rotated freely from a horizontal state to a vertically downward state and vice versa.

As a result, the excavating blade 5, the co-rotation preventing blade 6 and the stirring blade 7 extend long to the outside of the steel pipe 2 when the tip portions 5a, 6a and 7a are extended horizontally (FIG. 2 (a)). )), While the tip portions 5a, 6a, 7
When "a" rotates downward and is in a vertical state, the length is such that it can pass through the inside of the steel pipe 2 (FIG. 2 (b)).
reference).

A solid material injection port 8 is formed at the tip of the rotating rod 3, and solidified material injection ports 9 and 10 are formed on the stirring blade 7, both of which are underground through the rotary rod 3 from the ground. Is formed as an injection port for injecting the solidified material injected into the excavated soil excavated by the excavation bit 4 and the excavation wing 5.

In particular, the solidified material injection port 9 is formed at the tip of the stirring blade 7 so as to inject the solidified material almost directly upward into the excavated soil generated outside the steel pipe 2. Further, the solidified material injection port 10 is formed at the center of the stirring blade 7 so as to inject the solidified material obliquely toward the inner surface of the steel pipe 2.

The solidified material injection port 10 may be provided, for example, on the side surface of the rotating rod 3 as shown in FIG. 3, and the solidified material injection ports 9 and 10 are not provided on the stirring blade 7, It may be formed on the excavation wing 5.

Further, the solidified material injection ports 9 and 10 may be formed on all the stirring blades 7 or the cutting blades 5, or may be formed only on some of the stirring blades 7 or the cutting blades 5.

That is, as shown in FIG. 2, the construction apparatus for soil cement pile construction has a structure in which at least one excavating wing and a stirring wing are attached to the tip of the rod, and the vicinity of at least one of the stirring wings is close to the tip. And a solid material injection port 9 opening toward the inner surface of the steel pipe at least in one of the stirring blades. As shown in FIG. 2B, even when passing through the inside of the steel pipe, the solidified material injection port 10 opened toward the inner surface of the steel pipe.
Since the solidified material can be injected from the surface of the steel pipe toward the inner surface of the steel pipe, this device can be used to simultaneously lay down the steel pipe while simultaneously producing a soil cement column with a rod equipped with a drilling blade and a stirring blade at the tip. Injecting the solidified material from the injection port provided in at least one of the stirring blades to a position outside the steel pipe, and directing the solidified material from the other injection port provided in one of the topmost stirring blades to the inner surface of the steel pipe. The method of constructing a steel pipe soil cement pile is characterized in that the steel pipe is laid while spraying the solidified material. A steel pipe soil characterized by the fact that soil cement, which is a cement and contains a solidifying agent richer than the soil cement of the steel pipe inner core, is present on the inner surface of the steel pipe. It can be a cement pile.

Further, as shown in FIG. 3, the construction apparatus for soil cement pile construction is directed upward at least in the vicinity of the tip of at least one of the stirring blades of the rod having the tip mounted with the excavating blade and the stirring blade. And has a solidified material injection port 9 opened toward the inner surface of the steel pipe protruding from the rod. When this device is used, at least the excavation wing and the solidified material injection port 9 are opened. When simultaneously constructing a soil cement column with a rod with a stirring blade attached to the tip, and simultaneously laying down a steel pipe, a solidified material is injected from an injection port provided in at least one of the stirring blades to a position outside the steel pipe. While the steel pipe is sunk, the rod with the excavation wing and the stirring wing attached to the tip is closed when the digging wing and the stirring wing are closed and the steel pipe pile is pulled up. The steel pipe soil cement pile construction method characterized by injecting the solidified material toward the steel pipe inner surface from another injection port provided in the steel pipe, the soil cement outside the steel pipe is It is characterized by the fact that the soil cement is richer in solidifying material than soil cement, and that the soil cement, which is richer in hardening material than the soil cement in the core of the steel pipe, is present on the inner surface of the steel pipe. It can be a steel pipe soil cement pile.

Embodiment 3 of the Invention Next, an example of a method for constructing a steel pipe soil cement pile according to the present invention in such a configuration will be described with reference to FIGS.

First, the rotating rod 3 is passed through the steel pipe 2, and the excavation blade 5, the co-rotation prevention blade 6 and the tip portions 5a, 6a and 7a of the stirring blade 7 are horizontally extended, respectively.
Then, the rotating rod 3 is driven (rotated) to start excavation with the preceding excavating bit 4 and the excavating wing 5 rotating together with the rotating rod 3, and at the same time, the solidified material is injected into the excavated soil from the solidified material jets 8, 9 and 10. Inject.

When the excavation is started, the excavated soil and the solidified material are agitated and mixed by the stirring blade 7 rotating together with the rotary rod 3 in parallel with the excavation, and thereby the soil cement column is moved from the surface to the ground. The body 1 is constructed continuously.

Further, in parallel with the construction of the soil cement column 1, the steel pipe 2 is gradually laid in the soil cement column 1. When the resistance is large, the steel pipe 2 may be sunk while rotating.

At this time, the solidified material is injected from the solidified material injection port 9 to the outside of the steel pipe 2 and the solidified material is injected from the solidified material injection port 10 toward the inner surface excavated soil of the steel pipe.
Outside, the solidified material supplied from the solidified material injection port 8 and the excavated soil are mixed and stirred into the solid cement injection port 9.
Is added, so that the rich cement soil 1a is formed on the outside of the steel pipe 2, and the solidified material supplied from the solidified material injection port 8 and the excavated soil are mixed on the inner surface side of the steel pipe. The solidified material supplied from the solidified material injection port 10 is added to the agitated soil cement, and the solidified material supplied from the solidified material injection port 10 is concentrated on the steel pipe 2 as a wall to form an inner surface of the steel pipe. Therefore, a rich cement soil 1b is formed on the inner surface side of the steel pipe. Of course, the solidified material injected from the solidified material injection port 9 and / or the solidified material injection port 10 may have a high concentration.

After the construction of the soil cement column 1 and the laying of the steel pipe 2 are completed, the amount of the solidified material injected is increased, and the root stake 1d made of rich cement cement at the tip of the pile is about twice the diameter of the steel pipe. , The rotary rod 3 is pulled up to complete the construction. Thus, a steel pipe soil cement pile in which the soil cement column 1 and the steel pipe 2 are integrated is manufactured.

When the rotating rod 3 is pulled up inside the steel pipe 2, the excavating wing 5, the co-rotation preventing wing 6 and the stirring wing 7, which extend to the outside of the steel pipe 2, have their tips 5a, 6a, 7a rotated downward. Since it is folded vertically, it does not hit the lower end of the steel pipe 2. Embodiment 4 of the Invention FIG. 4 shows another example of the construction example of the steel pipe soil cement pile according to the present invention.
It will be described based on.

The apparatus for constructing a steel pipe soil cement pile shown in FIG. 4 has a solid material injection opening upwardly opening near at least one end of the stirring blade of a rod having at least a cutting blade and a stirring blade attached to the tip. 4 (not shown in FIG. 4, but has the same structure as the solidified material injection port 9 in FIGS. 2 and 3), and as shown in FIG. It is characterized by having a solidified material injection port 10 that opens horizontally from at least one of the stirring blades in a closed state.
When constructing a soil cement column at the same time as constructing a soil cement column with at least a drilling wing and a stirring blade attached to the tip of the steel tube, when the steel pipe is laid down, the solidified material is discharged from the injection port provided in at least one of the stirring blades to the outside of the steel pipe. While injecting toward the position, it is possible to carry out a steel pipe soil cement pile construction method characterized by sinking the steel pipe while injecting the solidified material toward the inner surface of the steel pipe from the injection port projected from the rod, The soil cement outside the steel pipe is considered to be richer in solidifying material than the soil cement in the inner core of the steel pipe, and the soil cement richer in solidifying material than the soil cement in the inner core of the steel pipe is applied to the inner surface of the steel pipe. The steel pipe soil cement pile is characterized by being present in the portion.

That is, the solidified material injection port 10 is closed, and the rod 3 is lowered while rotating, so that the excavation by the preceding excavation bit 4 and the excavation blade 5 and the setting of the steel pipe 2 are started. When the excavation is started, the solidified material injection port 8 (not shown in FIG. 4, but has the same structure as the solidified material injection port 8 in FIGS. 2 and 3) by the stirring blade 7 in parallel with the excavation. The solidified material and excavated soil are mixed and stirred to form soil cement.

At this time, the solidified material is injected from the solidified material injection port 9 (not shown in FIG. 4, but has the same structure as the solidified material injection port 8 in FIGS. 2 and 3) to the outside of the steel pipe 2. Have been. Therefore, on the outside of the steel pipe 2, the solidified material supplied from the solidified material injection port 9 is added to the soil cement in which the solidified material supplied from the solidified material injection port 8 and the excavated soil are mixed and stirred. The layer of soil cement 1a with a rich blend is continuously formed from the surface of the ground to the ground outside the outside.

The soil cement is continuously formed inside the steel pipe 2 from the ground surface to the ground. The soil cement supplied from the solidified material injection port 8 is poorly mixed as compared with the soil cement 1 a outside the steel pipe 2 because the solidified material is supplied only from the solidified material injection port 8.

In FIG. 4, the solidified portion 1d is rich in the high solidified material supplied from the solidified material injection port 8 only to the solidified portion. After the formation of the soil cement and the laying of the steel pipe 2 are completed,
This time, the solidified material injection ports 8 and 9 are closed, and as shown in FIG. 4A, the diameter of the excavator blade and the stirring blade is reduced (closed), and FIG.
As shown in (1), while the solidified material is being injected from the solidified material injection port 10 toward the inner surface of the steel pipe 2 and simultaneously the rotating rod 3 is rotated, the entire apparatus is gradually pulled up.

Thus, on the inner surface of the steel pipe 2, the solidified material supplied from the solidified material injection port 10 is added to the soil cement in which the solidified material supplied from the solidified material injection port 8 and the excavated soil are mixed and stirred. Therefore, the solidified material supplied from the solidified material injection port 10 is concentrated and deposited on the steel pipe 2 as a wall and exists on the inner surface side of the steel pipe 2. Is continuously formed from underground to the surface.

The soil cement 1c inside the steel pipe 2
Is that only the solidified material is supplied from the solidified material injection port 8 as described above, and is not supplied from the other.
Poor mix compared to soil cement 1b on the inner surface of steel pipe 2. In this way, a steel pipe soil cement pile is constructed.

[0056]

The present invention has been described above.
The steel pipe soil cement pile according to the present invention is filled with poorly-mixed soil cement in the center of the steel pipe, which does not require much strength (mainly compressive strength) as a support pile, and high strength is required for the support pile. The outside of the steel pipe and near the inner surface of the steel pipe are filled with richer (higher strength) soil cement than the central part of the steel pipe. I can say.

Further, by determining the injection amount of the solidifying material for each location in accordance with the required strength of the soil cement, the total amount of the solidifying material used can be reduced. The amount of excavated soil is small and easy to treat.

Further, since the high-strength soil cement layers are respectively formed on the outer and inner surfaces of the steel pipe, the adhesive force between the steel pipe and the soil cement is increased, and a large peripheral friction force can be exerted. Large support performance and seismic performance as a pile can be enhanced.

Further, since the high strength of the soil cement outside the steel pipe can exert a large adhesive force, even if an inexpensive ordinary steel pipe having no external projection is used, the peripheral surface frictional force can be exerted. It is possible to improve the large support performance and seismic performance of the pile.

Further, since the solidified material is always sprayed on the outer surface of the tip of the steel pipe, the adhesion of the viscous soil can be prevented, and the adhesion to the steel pipe at the tip where the solidified material is extremely rich is significantly improved. Also, the vertical support force at the tip is improved.

When the steel pipe is laid, a solidifying material is sprayed on the inner surface of the steel pipe, or when the drilling blade and the stirring blade are reduced in diameter (closed) and the pile construction device is pulled up inside the hollow portion of the steel pipe,
Since the solidified material is injected from the solidified material injection port to the inner surface of the steel pipe, it is possible to prevent the viscous soil from adhering to the surface of the steel pipe, or to grind the adhered viscous soil into soil cement.

For this reason, the adhesive force between the inner surface of the steel pipe at the tip and the solidified material is improved, and even when a rock-fixed portion is formed at the tip, there is a richer layer inside the steel pipe. In combination with the portion, the adhesive force between the inner surface of the steel pipe and the solidified material at the tip portion is remarkably improved, so that the effect of closing the tip by root compaction is greatly improved.

In particular, when the cohesive soil layer is directly above the support layer, the adhesion of the cohesive soil is likely to occur at the deepest part of the steel pipe, and therefore, the inner surface of the steel pipe is at least one-third of the diameter of the steel pipe from the deepest part of the steel pipe. The solidified material may be injected into the steel pipe so as to form a rich soil cement with a double length, preferably three times the diameter of the steel pipe.

As described above, according to the present invention, even when the steel pipe with surface projections is not used, the viscous soil adhering to the outer surface of the steel pipe and the inner surface of the steel pipe is converted into soil cement, and therefore, the soil cement is formed on both the outer surface of the steel pipe and the inner surface of the steel pipe. The result is a steel pipe soil cement pile with increased adhesion between steel pipe and steel pipe. Also,
According to this construction method and apparatus, the above-mentioned steel pipe soil cement pile can be constructed easily.

[Brief description of the drawings]

FIG. 1 shows an example of a steel pipe soil cement pile according to the present invention, in which (a) is a cross-sectional view and (b) is a longitudinal cross-sectional view.

FIG. 2 shows a method and an apparatus for constructing a steel pipe soil cement pile according to the present invention, wherein (a) and (b) are longitudinal sectional views.

FIG. 3 is a longitudinal sectional view showing a method and an apparatus for constructing a steel pipe soil cement pile according to the present invention.

4A and 4B show a method and an apparatus for constructing a steel pipe soil cement pile according to the present invention, wherein FIG. 4A is a longitudinal sectional view, and FIG. 4B is an enlarged longitudinal sectional view of FIG.

FIG. 5 is a cross-sectional view showing an example of a conventional steel pipe soil cement pile.

6 (a) to 6 (e) are longitudinal sectional views showing a conventional method and apparatus for constructing a steel pipe soil cement pile.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Soil cement pillar 1a Rich blended soil cement 1b Rich blended soil cement 1c Poorly blended soil cement 1d Rooting part 2 Steel pipe 3 Rotating rod 4 Preceding drill bit 5 Drilling wing 5a Tip part 6 Co-rotation prevention wing 6a Tip part 7 Stirring blade 7a Tip 8 Solidified material injection port 9 Solidified material injection port 10 Solidified material injection port

Continued on the front page (71) Applicant 000133881 Tenox Co., Ltd. 6-13-7 Akasaka, Minato-ku, Tokyo (71) Applicant 000004617 Nippon Sharyo Manufacturing Co., Ltd. 1-1 1-1 Sanbonmatsucho, Atsuta-ku, Nagoya-shi, Aichi, Japan (71) Applicant 392000453 JTC Corporation 2-3-4 Nishi-Shimbashi, Minato-ku, Tokyo (72) Inventor Yukihito Yoshizawa 4-5-33 Kitahama, Chuo-ku, Osaka-shi, Osaka Sumitomo Metal Industries, Ltd. (72 Inventor Yuki Oka 2-6-3 Otemachi, Chiyoda-ku, Tokyo New Nippon Steel Corporation (72) Inventor Norihiko Suzuki 3-3-1 Nihonbashi Muromachi 3-chome, Chuo-ku, Tokyo Kubota Corporation (72) Inventor Horikiri Setsu 6-13-7 Akasaka, Minato-ku, Tokyo Inside Tenox Co., Ltd. (72) Inventor Yoichi Shibayama 1-1, Sanbonmatsucho, Atsuta-ku, Nagoya-shi, Aichi Japan Vehicle Manufacturing Co., Ltd. Takahiro Shiroko 2-6-2 Nishi-Shimbashi, Minato-ku, Tokyo 6F Formula company Jay Thi sheet over the F-term (reference) 2D041 AA03 BA13 DA13 DB02 EA05 FA03 2D050 AA06 CA02 CA05 CB06 CB43

Claims (7)

[Claims] 1. A steel cement column composed of excavated soil and a solidified material and a steel pipe installed in the soil cement column, and having a higher mixing ratio near the outer and inner surfaces of the steel pipe than at the center of the steel pipe. A steel pipe soil cement pile characterized by being filled with soil cement. 2. A steel pipe soil in which a solidification material is injected into excavated soil at the time of excavation by using a pile construction device, and agitated and mixed to construct a soil cement column, and a steel pipe is laid in the soil cement column. A method for constructing a steel pipe soil cement pile, comprising injecting a solidifying material near the outer and inner surfaces of the steel pipe. 3. A steel pipe soil in which a solidification material is injected into excavated soil at the time of excavation by using a pile construction device, and agitated and mixed to construct a soil cement column, and a steel pipe is laid in the soil cement column. In the method for constructing a cement pile, a steel pipe soil is characterized in that a steel pipe is laid while spraying a solidifying material on the outside of the steel pipe, and then the pile construction device is pulled up while spraying the solidifying material near an inner surface of the steel pipe. Construction method of cement pile. 4. The method for constructing a steel pipe soil cement pile according to claim 2, wherein the solidified material is sprayed toward the inner surface of the steel pipe inside the steel pipe. 5. A construction apparatus for a steel pipe soil cement pile formed of a soil cement column made of excavated soil and a solidified material and a steel pipe installed in the soil cement column, wherein a rotating rod penetrating the steel pipe is provided. At least a drilling wing and a stirring blade are respectively protruded from the tip portion, and a solidification material injection port for injecting a solidification material near the outer and inner surfaces of the steel pipe is provided on the drilling wing or the stirring blade, respectively. Construction equipment for steel pipe soil cement piles. 6. An apparatus for constructing a steel pipe soil cement pile formed by a soil cement column made of excavated soil and a solidified material and a steel pipe installed in the soil cement column, wherein the steel pipe is In a device in which at least a digging wing and a stirring blade are respectively provided at a tip portion of a rotating rod penetrating, a solidification material injection port for injecting a solidification material near an outer surface of the steel pipe is provided on the digging blade or the stirring blade. And a solid material injection port for injecting a solidified material toward the inner surface of the steel pipe on the excavating wing or stirring blade, or the rotating rod, wherein the steel pipe soil cement pile is characterized in that: Construction equipment. 7. The construction apparatus for a steel pipe soil cement pile according to claim 5, wherein the excavating wing and the stirring wing are provided so as to increase and decrease in diameter.