JPH07268867A - Cast-in-place concrete pile and method for fabricating the same - Google Patents

Abstract

PURPOSE:To increase a supporting force by a method wherein the lower end of an existing concrete pile is inserted into a root portion of an expaned-bottom shaped concrete having a diameter larger than that of the pile and concrete is filled into the inner hole of the pile and into a gap between the external wall of the pile and a pile hole so as to be cured. CONSTITUTION:A pile hole 1 is excavated by means of an excavation rod and thereafter an expanded bottom section 4 is formed at the lower part of the pile hole 1 by means of an excavation head. Next, a concrete pile 5 is inserted into the hole 1 and concrete 7 is cast through a tremie pipe. And if the concrete 7 is cast, while the tremie pipe is pulled up, the concrete 7 is filled into the inner hole of the pile 5 and into a gap between the inner wall of the pile hole 1 and the outer wall of the pile. Further, if the upper surface of the concrete 7 reaches the ground surface 10, filling of concrete is stopped, allowing the concrete to be cured, whereby a cast-in-place concrete pile having a length 5-20m is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a field construction pile and a construction method thereof for the purpose of obtaining a pile having a large bearing capacity.

[0002]

2. Description of the Related Art Conventionally known is a field construction pile in which a pile hole is dug in a site, a reinforcing steel basket is inserted, and then concrete is filled and solidified.

Further, there is known a method of penetrating a ready-made pile in which a pile hole is dug at a site, a ready-made pile is inserted and installed in the pile hole, and then a pile circumference fixing liquid is filled on the bottom of the pile hole and the outside of the ready-made pile (Japanese Patent Laid-Open No. 2000-242242). Sho 6
2-253817).

[0004]

Among the above-mentioned conventional techniques, the former site-built reinforced concrete pile can form a significantly large diameter pile, but it is difficult to obtain uniform strength throughout, and it takes a lot of time and labor. There is a point. In addition, the latter is originally a method of penetrating prefabricated piles, and although it reinforces prefabricated piles, it has the problem that it cannot be an independent on-site constructed pile.

For example, a ready-made pile with a diameter of 50 cm has a diameter of 60 cm.
It is possible to penetrate into the pile hole, but it is not possible to make a field pile with a diameter of 100 cm.

[0006]

However, according to the present invention, by using a prefabricated pile in place of the reinforcing bar cage or a part thereof,
The above-mentioned conventional problems have been solved.

That is, in the invention of the article, the lower end of the ready-made concrete pile is inserted into the root of the expanded concrete having a diameter larger than that of the ready-made concrete pile, and the space between the inner hole of the ready-made concrete pile and the outer wall and the pile hole. It is an on-site constructed concrete pile characterized by being filled with concrete and hardened to form an integral concrete pile. Still another invention is to insert the lower end of a prefabricated concrete pile into a concrete root part having a diameter larger than that of the prefabricated concrete pile and having the outer diameter sequentially increased toward the tip, and the prefabricated concrete pile is used. It is an on-site constructed concrete pile characterized in that concrete is filled and hardened between the inner hole, the outer wall and the pile hole to form an integral concrete pile. Next, the invention of other things, at the lower end of the ready-made concrete piles provided with communication holes with the inside on the side wall,
On-site construction characterized by being inserted into a bottomed concrete root and being filled and hardened with concrete between the inner hole, the communication hole and the outer wall of the ready-made concrete pile and the pile hole to form an integral concrete pile It is a concrete pile. Still another invention is to insert the lower end of a prefabricated concrete pile provided with an uneven portion on the side wall into a concrete root part with a bottomed-out shape, and to put concrete between the inner hole and the outer wall of the prefabricated concrete pile and the pile hole. An on-site constructed concrete pile characterized by being filled and hardened to form an integral concrete pile.

Further, in the invention of the method of construction, a pile hole is excavated at a position for constructing a pile on site and an expanded bottom portion of a predetermined size is provided. Next, insert the tremie pipe, fill the expanded bottom with concrete, take out the tremie pipe, insert and install the required number of ready-made concrete piles at a predetermined interval, then insert the tremie pipe into the concrete pile, and lower the bottom of the pile hole. A method of constructing a site-built concrete pile characterized in that the tremie pipe is pulled up while filling the concrete from the side, the concrete is filled in the concrete pile and the pile hole, and the concrete pile and the filled concrete are integrally hardened. is there.

Another invention of the construction method is at the on-site pile construction position,
Excavating a predetermined pile hole, providing a predetermined expanded bottom portion to this, and then inserting a reinforcing steel basket for the lower part into the pile hole, and after inserting a ready-made concrete pile into the upper part of the reinforcing steel basket, with the ready-made concrete pile The tremie pipe is inserted into the reinforced basket, the concrete is pushed out from the lower end of the tremie pipe while the tremie pipe is pulled up, the concrete is filled into the pile holes and the reinforced basket and ready-made concrete, and the concrete is cured. This is a construction method for on-site concrete piles.

In the above description, a single prefabricated pile is used in each case, but it is also possible to use a plurality of piles. For example, diameter 3
In order to build m piles, use 5 ready-made concrete piles with a diameter of 80 cm.

In the above description, the concrete to be filled in the root portion of the pile hole was filled before the ready-made concrete pile (or the reinforced basket) was inserted, but the ready-made concrete pile was inserted first, and then the concrete was filled through the tremie pipe. You can also do it.

In the invention of the construction method, the upper end of the rebar cage and the lower end of the ready-made concrete are connected to each other according to the site, such as crossing of the two rebars, metal bonding or welding.

The length of the ready-made concrete is intended to cover the depth at which bending stress and other external forces are large in consideration of variations due to the formation, and the length is 5 to 20 m.
Is normal.

[0014]

According to the present invention, since the ready-made concrete pile is used in place of the reinforced cage, the amount of work at the site can be reduced and the strength reliability of the site constructed pile can be improved. In addition, on-site piles with a large diameter (for example, diameter of 1 m or more) can be made by using ready-made piles.

[0015]

Embodiment 1 Embodiments of the present invention are shown in FIGS.
8, 9, and 10 will be described.

The pile hole 1 is excavated by the excavating rod 2 to the site where the on-site constructed pile is to be installed, and then the bottom portion 4 is provided below the pile hole 1 instead of the excavating head 3. The expanded bottom portion 4 may have a rectangular cross section, but in FIGS. 1, 6 and 7, the cross section has a truncated cone shape.

Then, after the ready-made concrete pile 5 is inserted (FIG. 7), the tremie pipe 6 is inserted (FIG. 8), and the concrete 7 is filled through the tremie pipe 6.

Next, when the tremie pipe 6 is raised as shown by the arrow 8 and is filled with concrete 7, not only the inner hole 5a of the concrete pile 5 but also the inner wall 1 of the pile hole 1 is filled with the concrete 7.
a and the space 9 between the outer wall 5b of the concrete pile 5 are sequentially filled, and the filling is stopped when the upper surface of the concrete 7 reaches the ground surface 10 and the concrete 7 is hardened. 11 can be created.

According to the above-mentioned embodiment, since concrete piles are used in place of the reinforced baskets, the strength of the constructed piles is not only high, but also the amount of concrete used on site is small and the construction period is shortened. be able to.

[0020]

Embodiment 2 In this embodiment, as shown in FIGS. 2 and 3, an inner / outer communication hole 13 is provided in a side wall of a concrete pile 12, or
The convex portion 17 is provided on the outer wall of the concrete pile 14 to form cast-in-place concrete piles 18 and 19.

Therefore, the method of excavating the pile hole 1 and the method of inserting the concrete pile are the same as those in the first embodiment, and the description thereof will be omitted.

According to the above embodiment, the concrete pile 1
There is an advantage that the integrity of the concrete 2 and 14 and the cast-in-place concrete 7 becomes tighter.

[0023]

[Embodiment 3] In the embodiment shown in FIGS. 4A and 4B, five concrete piles 15 are inserted into the pile hole 1. For example, a concrete pile with an outer diameter of 80 cm in a pile hole 16 with an inner diameter of 3 m
Five piles 5 were inserted at a predetermined interval, and concrete 7 was filled between the piles to construct a pile on site having an outer diameter of 3 m.

As mentioned above, when the required outside diameter of the field pile is large, it is possible to easily construct a field pile having a uniform supporting force by using a plurality of concrete piles.

[0025]

Fourth Embodiment Another embodiment of the present invention will be described with reference to FIGS.

In FIG. 10, the pile hole 1 is excavated in the site where the site-constructed pile is to be installed, the expanded bottom portion 4 is provided in the lower portion of the pile hole 1, the rebar cage 20 is inserted, and the upper end of the rebar cage 20 is inserted. To rebar 22 protruding from the lower end of ready-made concrete pile 21
And the ready-made concrete piles 21 are also inserted and installed.

Next, the ready-made concrete pile 21 and the rebar cage 2
Insert the tremie pipe into 0, and then raise it while filling the concrete 7 from the tip of the tremie pipe, fill the inside and outside of the reinforced cage 20 and the inside and outside of the ready-made concrete pile 21 with the concrete 7, and make it flush with the ground surface 10. When it becomes, stop filling.

When the concrete 7 is hardened and integrated with the ready-made concrete pile 21 and the reinforced basket 20, the cast-in-place concrete pile 23 of the present invention can be obtained.

In the above embodiment, after the pile hole 1 was excavated, the reinforced cage 20 and the ready-made concrete pile 21 were first inserted into the pile hole 1, and then the concrete 7 was filled through the tremie pipe. It is also possible to fill a predetermined amount of concrete 7 before putting in, and then insert the reinforced basket 20 and the ready-made concrete pile 21. FIG. 11 shows two rebar cages 2 instead of one rebar cage in the above embodiment.
0, 20 and ready-made concrete piles 21, 21 are inserted, and when constructing a large-diameter cast-in-place pile 24, not only two ready-made concrete piles 21 are used,
Sometimes three or more are used.

It is also possible to make the pile hole 1 a plane ellipse, use a plane elliptical concrete pile, or use a plurality of plane circular concrete piles.

[0031]

EFFECTS OF THE INVENTION The present invention inserts and installs ready-made concrete piles or ready-made concrete piles and reinforced baskets into pile holes excavated at the site, fills concrete inside and outside of the concrete piles, etc. and hardens them integrally. Therefore, there is an effect that it is possible to easily construct on-site piles with high reliability of bearing capacity. However, there is an effect that a large-diameter (3 m diameter, etc.) on-site constructed pile can be easily and highly strongly constructed.

However, not only is the amount of cast-in-place concrete relatively small, but the ready-made concrete pile has a predetermined strength immediately after construction, so that there are various effects such that workability is extremely good and the construction period can be shortened.

[Brief description of drawings]

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

FIG. 2 is a sectional view of another embodiment of the same.

FIG. 3 is a sectional view of an example in which unevenness is provided on the outer wall of the concrete pile.

FIG. 4 (a) is a sectional view of an embodiment using a plurality of concrete piles. (B) Similarly, a plan view.

FIG. 5 is a sectional view of pile hole excavation in the embodiment of the construction method of the present invention.

FIG. 6 is a cross-sectional view showing the excavation of the expanded bottom portion.

FIG. 7 is a sectional view in which a concrete pile is also inserted.

FIG. 8 is a sectional view of concrete partially filled with a tremie pipe.

FIG. 9 is a cross-sectional view at the time of filling concrete while ascending the tremie pipe.

FIG. 10 is a sectional view of another embodiment of the same.

FIG. 11 is a sectional view of the case where a plurality of ready-made concrete piles are used.

[Explanation of symbols]

 1 Pile Hole 2 Excavation Rod 3 Excavation Head 4 Expanded Bottom 5 Concrete Pile 6 Tremy Pipe 7, 12, 14, 15 Concrete 9 Void 10 Ground Surface 11 Site-cast Concrete Pile 13 Communication Hole 14, 21 Concrete Pile 18, 19 Cast-in-place Concrete Pile 20 Rebar cage 22 Rebar

Claims (8)

[Claims] 1. A lower end of a prefabricated concrete pile is inserted into a root portion of a bottomed concrete having a diameter larger than that of the prefabricated concrete pile, and concrete is filled between an inner hole of the prefabricated concrete pile and an outer wall and a pile hole. An on-site constructed concrete pile characterized by being hardened into an integral concrete pile. 2. An inner hole of the ready-made concrete pile, wherein a lower end of the ready-made concrete pile is inserted into a concrete root part having a diameter larger than that of the ready-made concrete pile and an outer diameter of which is gradually increased toward a tip thereof. An on-site constructed concrete pile, characterized by filling and hardening concrete between the outer wall and the pile hole to form an integral concrete pile. 3. A lower end of a prefabricated concrete pile having a side wall provided with a communication hole to the inside is inserted into a concrete root portion having an expanded bottom shape, and an inner hole, a communication hole, and an outer wall and a pile hole of the prefabricated concrete pile. An on-site constructed concrete pile characterized by being filled and hardened with concrete to form an integral concrete pile. 4. The lower end of a prefabricated concrete pile having an uneven portion on a side wall is inserted into a concrete root portion having a bottom-like shape, and concrete is filled between an inner hole and an outer wall of the prefabricated concrete pile and a pile hole. An on-site constructed concrete pile characterized by being hardened into an integral concrete pile. 5. A pile hole is excavated at a site pile construction position, and a bottom expansion portion of a predetermined size is provided. Next, put the tremie pipe, fill the expanded bottom with concrete and take out the tremie pipe, insert and install the required number of ready-made concrete piles at predetermined intervals, then insert the tremie pipe into the concrete pile,
A site-created concrete pile characterized in that the tremie pipe is pulled up while filling the concrete from the lower end side of the pile hole, the concrete is filled into the concrete pile and the pile hole, and the concrete pile and the filled concrete are integrally hardened. Construction method. 6. A predetermined pile hole is excavated at a site pile formation position, a predetermined expanded bottom portion is provided therein, and then a reinforcing steel cage for a lower portion is inserted into the pile hole, and a ready-made concrete is provided above the reinforcing steel cage. After inserting the pile, insert the tremie pipe into the prefabricated concrete pile and the reinforced basket, push out the concrete from the lower end of the tremie pipe, and while pulling up the tremie pipe, fill the hole in the pile and the reinforced basket and the precast concrete with concrete. And a method for constructing an on-site constructed concrete pile, characterized by hardening the concrete. 7. A reinforcing bar at the lower end of a ready-made concrete pile,
7. The reinforcing bar basket is connected to the upper end of the basket.
Construction method for the on-site constructed concrete pile described. 8. The length of the ready-made concrete pile is 5 m to 2
The method for constructing an on-site constructed concrete pile according to claim 6, wherein the construction length is 0 m.