JP2002363979A - Pile construction method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pile construction method capable of reducing amounts of soil cement and sediment remaining on an inner side of a pile head part of an existing hollow pile and applicable to not only a steel pile but also other existing hollow pile without using a steel pipe having, in particular, a special structure. SOLUTION: First, a plurality of hollow piles 1 excepting an upper end pile 1a (hollow pile at the uppermost step) are sunk and provided by connecting them mutually in soil cement 2 while forming the soil cement 2. Next, the soil cement 2 is further formed down to a depth equivalent to a length of sinking of at least the upper end pile 1a below the hollow pile 1. Then, the soil cement 2 in the sunk hollow pile 1 is removed down to a depth equivalent to at least about ten times a pile outside diameter from a pile upper end. Next, the upper end pile 1a is connected with an upper end of the hollow pile 1 and is sunk into the soil cement 2 down to a position where its pile head part remains above a lower end face of footing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a footing or footing beam for transmitting a load from a structure built on the ground to the ground, and particularly to a pile for easy connection with a footing or footing beam. The present invention relates to a pile construction method for constructing a pile having a cavity for inserting and fixing a footing connection member such as a reinforcing bar inside a head.

[0002]

2. Description of the Related Art In recent years, a steel pipe soil cement pile formed by depositing a steel pipe in soil cement has been adopted as a foundation pile for supporting a structure built on the ground. In addition, as a method of joining the pile head of this type of steel pipe soil cement pile and the footing or footing beam created as a part of the foundation of the structure built on the ground, reinforcing steel etc. And a footing or footing beam is integrally joined to the pile head of the steel pipe soil cement pile via the footing connection member.

In this case, the footing connecting member is generally inserted into a steel pipe at the pile head of a steel pipe soil cement pile,
It is fixed to the pile head of the steel pipe soil cement pile by filling concrete around it, but since the steel pipe at the pile head is filled with soil cement, before filling concrete, the pile head is It is necessary to remove the soil cement in the steel pipe filled to a predetermined depth to a predetermined depth.

However, it takes a considerable amount of time and cost to completely remove the semi-hardened soil cement in the steel pipe, and it is very difficult to completely remove the soil cement attached to the inside of the pile.

For this reason, soil cement tends to remain in the steel pipe at the head of the pile, and the remaining soil cement is a major factor hindering the integration of the pile with the concrete, and various problems have been raised. .

More specifically, if soil cement remains in the steel pipe at the head of the pile, especially inside the steel pipe, when a shear force acts between the superstructure and the pile due to an external force such as seismic force, for example. Soil cement breaks down faster than concrete. For this reason, even if the footing connection member is firmly fixed to the pile head with concrete, it has to be a connection part with extremely low proof stress.

[0007] Such a problem is caused by the fact that soil and the like adhere to the inside of the steel pipe even when the soil and the like clogged at the pile head of the steel pipe pile are removed after the steel pipe is directly buried as a pile in the ground. Was happening.

[0008] By the way, as a method of constructing a steel pipe soil cement pile in which no soil cement remains in the steel pipe at the pile head, for example, Japanese Unexamined Patent Publication No.
A pile construction method disclosed in Japanese Patent No. 1574 is known.

In this method, for example, as shown in FIG.
Before the steel pipe 22 is laid as a pile in the soil cement 21 formed in the underground 20, a short pipe 23 having a smaller diameter than the steel pipe 22 can be detached from the inside of the upper end of the steel pipe 22 in advance via the mounting bracket 24. Is attached to the device by screws 24a.

By doing so, when the steel pipe 22 is sunk to the upper end in the soil cement 20, the soil cement 20 rises into the short pipe 23 having a smaller diameter than the steel pipe 22 at the upper end of the steel pipe 22, and Does not flow inside the
After hardening, the soil cement 21 in the short pipe 23 can be removed together with the short pipe 23.

[0011]

However, in order to adopt this method, as shown in the drawing, a steel pipe 22 having a special internal structure is used.
There is a problem that it is necessary to prepare a stake as a pile, which increases the cost in terms of processing and the like.

The present invention has been made in order to solve the above-mentioned problems, and in particular, without using a steel pipe having a special structure as described above, a soil cement, earth and sand, etc. are provided inside a pile head of a prefabricated hollow pile. It is an object of the present invention to provide a pile construction method which can reduce the remaining of piles and can be applied not only to steel pipes but also to other ready-made hollow piles.

[0013]

According to a first aspect of the present invention, there is provided a method of constructing a pile comprising a soil cement and a plurality of hollow piles below a footing. While the soil cement having a depth capable of sinking to the position is present and the hollow pile except the uppermost hollow pile is sunk in the soil cement, the soil cement in the hollow pile is removed from the top of the hollow pile. From at least a depth corresponding to at least about 10 times the outer diameter of the hollow pile, and then connect the uppermost hollow pile, and put the uppermost hollow pile above the lower end face of the footing. The soil cement is settled in the soil cement to a position where the soil cement remains.

According to a second aspect of the present invention, in the method for constructing a pile formed by soil cement and a plurality of hollow piles below the footing, a hollow excluding the uppermost hollow pile while forming the soil cement. Piles are sunk in the soil cement while being connected to each other as necessary, and then the soil cement is further formed below the hollow pile to at least a depth corresponding to the sunk length of the uppermost hollow pile, The soil cement in the hollow pile is removed from the upper end of the hollow pile to a depth corresponding to at least about 10 times the outer diameter of the hollow pile, and then the uppermost hollow pile is connected. The pile head is sunk in the soil cement to a position where the pile head remains above the lower end surface of the footing.

According to a third aspect of the present invention, in the method for constructing a pile formed by soil cement and a plurality of hollow piles below the footing, the soil cement is formed to a predetermined depth, and then the uppermost step is formed. The hollow piles except for the hollow piles are sunk while being connected to each other in the soil cement as required, and then the soil cement in the hollow piles is at least about 10 times the outer diameter of the hollow piles from the upper end of the hollow piles. And then connecting the uppermost hollow pile, and sinking the uppermost hollow pile into the soil cement until the pile head remains above the lower end surface of the footing. It is characterized by the following.

In any of the pile construction methods described above, after the uppermost hollow pile is laid, a reinforcing bar or the like is erected as a footing connecting member in the uppermost hollow pile, and then concrete is filled. A footing connection member such as a reinforcing bar can be securely fixed to the pile head. In this case, the concrete may be filled immediately after the footing connecting member such as a reinforcing bar is inserted into the uppermost hollow pile, or after a while.

The method for constructing a pile according to the present invention is particularly advantageous in that the uppermost hollow pile can be settled in the soil cement without being filled with soil cement at all. Components can be easily inserted and concrete can be filled in a sufficient amount,
The footing connection member can be securely fixed to the pile head.

In addition, since the pile head has a structure in which soil cement that prevents the integration of the pile and the concrete does not remain in the pile head, concrete is filled after the footing connecting member is installed in the pile head. Thus, the footing connection member can be integrally fixed to the pile head, and a footing connection portion having extremely high proof stress can be formed.

Further, by adopting a steel pipe as the hollow pile, not only the soil cement can be removed without considering the damage inside the pile, but also the steel pipe soil cement in which the soil cement and the steel pipe are integrated. Piles can be created.

According to a fourth aspect of the present invention, in the method for constructing a pile formed by a plurality of hollow piles below the footing, a hollow pile excluding the uppermost hollow pile while excavating the ground with an auger is required. And then excavating the lower part of the hollow pile with the auger to a depth corresponding to the length in which the uppermost hollow pile is to be installed, and bolstering the lower end thereof. Part is formed, and then the auger is collected and excavated soil in the hollow pile is removed from the upper end of the hollow pile to a depth corresponding to at least about 10 times the outer diameter of the hollow pile. And the uppermost hollow pile is buried underground to a position where the pile head remains above the lower end surface of the footing.

According to a fifth aspect of the present invention, in the method for constructing a pile formed by a plurality of hollow piles below the footing, the hollow piles except for the uppermost hollow pile may be connected to each other as needed. Then, the soil in the hollow pile is removed from the upper end of the hollow pile to a depth of at least about 10 times the outer diameter of the hollow pile, and then the uppermost hollow pile is connected. Is built up to a position where the pile head remains above the lower end surface of the footing.

In particular, the method for constructing a pile according to claim 5 is a method for constructing a pile in which a hollow pile is directly buried in the ground. A helical wing or the like can be provided and rotated to be directly buried in the ground.

Also, in the case where the auger is built in the hollow pile and the hollow pile is lowered while excavating the ground with the auger as in the construction method according to the fourth aspect, the construction according to the fifth aspect is further performed. Even when the hollow pile is directly erected by rotating, driving or pushing it into the ground as in the method, the steel pipe is preferable because it is resistant to twisting, and in the case of steel pipe, the outer periphery of the pile head becomes a steel pipe at the pile head. Since the structure is filled with concrete, a pile having a very high proof stress against horizontal stress can be formed.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 of the Invention Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIGS. 1 (a) to 1 (h) show that the soil cement 2 is continuously formed in a column shape below the hollow pile 1 and the hollow pile 1 is deposited in the soil cement 2 so that the soil cement 2 is formed. It is the figure which showed the process which shows one example which applied the pile construction method of this invention to the method of constructing the pile which integrated the hollow pile 1 with the hollow pile 1 in order.

First, a rod 4 having a drilling / mixing head 3 having a cement milk discharge port is inserted into the hollow pile 1, and the drilling / mixing head 3 is projected from the lower end of the hollow pile 1 (FIG. ) Is set as shown in FIG.

Next, the excavating / stirring head 3 is pushed into the ground together with the hollow pile 1 while rotating through the rod 4, and the excavating / stirring head 3 excavates the ground while extruding the cement milk from the cement milk discharge port. And the excavated soil are stirred and mixed to form the soil cement 2 continuously in a columnar shape in the direction of excavation. At the same time, if necessary according to the length of the pile to be formed, a plurality of hollow piles 1 are connected and added. When a steel pipe is used as the hollow pile 1 in this case, the hollow piles may be joined by welding. Further, the hollow pile 1 may be simply pushed into the soil cement 2 without being rotated, without being rotated. Further, in this case, the structure of the excavation / stirring head 3 and the rod 4 is
Any device can be used as long as it can form the device.

In this way, a plurality of hollow piles 1 are continuously laid in the ground except for the uppermost hollow pile 1 (hereinafter referred to as “upper pile 1a”), and the upper pile 1a (an example of a steel pipe pile is shown in the drawing). When the plurality of hollow piles 1 have been laid down to the position where they are to be connected, the laying of the hollow piles 1 is stopped.

Next, below the hollow pile 1 submerged in the ground, a soil cement 2 is further continuously formed in a columnar shape to a depth corresponding to the length in which the upper pile 1a is submerged. A bolster 5 is formed at the lower end. This state is shown in FIG. Soil cement 2 in this case
Is pushed into the ground while rotating the excavating / mixing head 3 via the rod 4, and while excavating the ground with the excavating / mixing head 3, the cement milk discharged from the cement milk discharge port and the excavated soil are mixed and mixed. It forms by doing. The root consolidation part 5 is formed by discharging high-concentration cement milk at the lower end of the soil cement 2.

Next, as shown in FIGS. 3 (c) and 3 (d), the excavation / agitation head 3 used for excavation and agitation of the soil is moved so that the excavation / agitation head 3 can pass through the hollow pile 1. The wings are folded and closed, and the hollow pile 1 is pulled up and the rod 4 is collected on the ground.

Next, as shown in FIG. 5E, a position where the depth from the pile upper end of the upper pile 1a to be subsequently constructed exceeds the depth H corresponding to about 10 times the outer diameter of the pile. Until the soil cement 2 in the hollow pile 1 is removed. As a method of removing soil cement in this case, a conventional soil which has been applied to remove soil cement from the pile at the pile head after laying a hollow pile in the soil cement as before. A method for removing cement may be applied.

Next, after removing the soil cement 2 in the hollow pile 1 to a position exceeding the depth H, the upper end pile 1 a is welded to the upper end of the hollow pile 1 as shown in FIG. Connecting.

Next, the upper pile 1 a is settled in the soil cement 2 while rotating if necessary. in this case,
The upper pile 1a is settled to a position where the pile head remains above the lower end surface of the footing, and the lower end of the lowermost hollow pile 1 is inserted into the rooting portion 5. This state is shown in FIG. An inner lid 6 may be provided at the lower end of the upper pile 1a. In this case, the lid 6 desirably has a small hole for venting air so as not to receive air resistance when the upper pile 1a is laid. By constructing in this manner, as shown in FIG. 9G, the inside of the upper end pile 1a to be filled with concrete later is in a state where no soil cement is present.

Next, a reinforcing bar 7 is inserted and fixed as a footing connection member in the head of the upper end pile 1a, and then, concrete 8 is filled in the upper end pile 1a. In this case, the inner lid 6 can function as a receiving member for preventing the reinforcing bar 7 and the concrete 8 from falling down. This state is shown in FIG.

Embodiment 2 of the Invention FIG. 2 (a) to (h)
Is formed by continuously forming the soil cement 2 in a columnar shape, and then depositing the hollow pile 1 in the soil cement 2.
It is a figure which shows in order the process which shows one example which applied the construction method of this invention to the construction method of the pile which constructs the pile which integrated the soil cement 2 and the hollow pile 1.

First, the soil cement 2 is continuously formed in a columnar shape to a depth corresponding to the length in which the entire length of the hollow pile is to be built, and a rooting portion 5 is formed at the lower end thereof. This state is shown in FIG. To form the soil cement 2, a rod 4 having a drilling / mixing head 3 having a cement milk discharge port is used, and the drilling / mixing head 3 is rotated via a rod 4 as shown in FIG. The cement milk discharged from the cement milk discharge port and the excavated soil are agitated and mixed while being pushed into the ground while excavating the ground with the excavation and agitation head 3. The root consolidation part 5 is formed at the lower end of the soil cement 2 by discharging particularly high-concentration cement milk. The structure of the excavation / stirring head 3 and the rod 4 in this case may be any structure as long as the soil cement 2 can be formed.

Next, when the formation of the soil cement 2 is completed, the rod 4 having the excavation / stirring head 3 is recovered. This state is shown in FIG. In the above description, when excavating with the excavating / stirring head 3, the cement milk is discharged to form the soil cement 2. However, when excavating without discharging the cement milk, the excavating / stirring head 3 is stirred up. The soil cement 2 may be formed by rotating the excavation / stirring bit 3 to stir / mix the cement milk and the excavated soil while discharging the cement milk from the discharge port above the wing.

Next, as shown in FIG. 4D, a hollow pile 1 (a state in which a plurality of hollow piles are connected if necessary. An example of a steel pipe pile is shown in the drawing) is shown in a soil cement 2. Submerging (for example, burying while rotating the pile). In this case, when a steel pipe is used as the hollow pile 1, the piles may be joined by welding. Further, the hollow pile 1 may be simply pushed into the soil cement 2 without being rotated, without being rotated.

Next, as shown in FIG. 4E, the soil in the hollow pile 1 is extended to a position where the depth from the upper end of the upper end pile 1a exceeds the depth H corresponding to about 10 times the outer diameter of the pile. The cement 2 is removed. As a method of removing soil cement in this case, the same method has been used to remove soil cement from the pile at the top of the pile after setting a hollow pile in the soil cement as before. The method of removing the soil cement can be applied.

Next, after the soil cement 2 in the hollow pile 1 has been removed to a position exceeding the depth H, the upper pile 1a is welded to the upper end of the hollow pile 1 as shown in FIG. Connecting. Then, the hollow pile 1a is settled in the soil cement 2 while rotating if necessary. in this case,
The upper pile 1a is settled to a position where the pile head remains above the lower end surface of the footing, and the lower end of the lowermost hollow pile 1 is inserted into the rooting portion 5. This state is shown in FIG. Also in this case, it is desirable to provide the inner lid 6 at the lower end of the upper pile 1a. By constructing in this manner, as shown in FIG. 9G, the inside of the upper end pile 1a to be filled with concrete later is in a state where no soil cement is present.

Next, a reinforcing bar 7 is inserted and fixed as a footing connection member in the head of the upper end pile 1 a, and then the hollow pile 1 a is filled with concrete 8. This state is shown in FIG.

Embodiment 3 of the Invention FIG. 3 (a) to (h)
Applied the pile construction method of the present invention to a pile construction method in which a screw auger 9 is passed through a hollow pile 1 and the pile is constructed by embedding the hollow pile 1 in an excavation hole while excavating with the screw auger 9. It is a figure which shows the process which shows an example in order.

First, the screw auger 9 is passed through the hollow pile 1 and set in a state as shown in FIG.

Next, the screw auger 9 is rotated and pushed into the ground together with the hollow pile 1, and the ground is dug by the screw auger 9. In parallel with the excavation of the ground, a plurality of hollow piles 1 are connected and added if necessary according to the length of the pile to be formed. When a steel pipe is used as the hollow pile 1 in this case, the piles may be joined by welding. Further, the hollow pile 1 may be pushed into the excavation hole while rotating, and may be sunk, or may be simply pushed without being rotated and sunk.

Next, the plurality of hollow piles 1 are sunk in the excavation hole, leaving the upper pile 1a, and the plurality of hollow piles 1 are connected to a position where the upper pile 1a (an example of a steel pipe pile is shown in the drawing). When the settlement is completed, the settlement of the hollow pile 1 is stopped.

Next, a further continuous excavation hole is formed below the hollow pile 1 submerged in the ground to a depth corresponding to the length of submerging the upper pile 1a. At the lower end of the drilling hole, the screw auger 9 is rotated while the cement milk and the excavated soil are agitated and mixed while discharging high-concentration cement milk from the tip of the screw auger 9 to thereby fix the root consolidation portion 5. To form After that, the screw auger 9 is collected on the ground as shown in FIGS.

Next, as shown in FIG. 5E, the hollow pile 1 is moved to a position where the depth from the upper end of the upper end pile 1 a exceeds a depth H corresponding to about 10 times the outer diameter of the pile. Remove excavated soil. As a method of removing excavated soil in this case, a conventional excavated soil, which has been applied when removing excavated soil from the pile at the head of the pile after burying a hollow pile in the ground as before, May be applied.

Next, after removing the excavated soil in the hollow pile 1 to a position exceeding the depth H, the upper pile 1a is connected to the upper end of the hollow pile 1 by welding or the like as shown in FIG. .
The upper pile 1a is settled in the excavated soil while rotating if necessary. In this case, the upper pile 1a is settled to a position where the pile head remains above the lower end face of the footing,
In addition, the lower end of the lowermost hollow pile 1 is inserted into the foundation 5. This state is shown in FIG. Also in this case, it is desirable to provide the inner lid 6 at the lower end of the upper pile 1a. By constructing in this manner, as shown in FIG. 9G, the inside of the upper end pile 1a to be filled with concrete later has no excavated soil. In the above example, the excavated soil in the hollow pile was removed. However, when excavating with the screw auger 9, cement milk was discharged to mix and agitate the cement milk and excavated soil to obtain soil cement. If the soil cement is removed, the upper pile 1a can be laid without the inner wall in contact with the soil cement.
The inner wall of a may be free of soil cement.

Next, a reinforcing bar 7 is inserted and fixed as a footing connection member in the head of the upper end pile 1a, and then, the concrete 8 is filled in the upper end pile 1a. Also in this case, the inner lid 6 is attached to the lower end of the upper end pile 1a. This state is shown in FIG.

Embodiment 4 of the Invention FIG. 4 (a) to (f)
FIG. 3 is a diagram showing an example in which the pile construction method of the present invention is applied to a pile construction method in which a hollow pile 1 is directly buried in the ground and constructed.

First, the hollow pile 1 is laid underground as shown in FIG. The submersion method may be a striking method or a push-in method. Not desirable. In that respect, a steel pipe is preferable as the hollow pile.

Next, as shown in FIG. 5B, when the hollow pile 1 is laid down to a position where the upper end pile 1a is connected,
As shown in FIG. (C), the soil that has entered the pile is removed to a position where the depth of the upper end pile 1a from the upper end of the pile exceeds a depth H corresponding to approximately 10 times the outer diameter of the pile. As a method of removing soil in this case, a conventional soil removal method that has been applied when soil is removed from inside the pile at the head of the pile after burying a hollow pile in the ground as before. May be applied.

Next, after the soil in the hollow pile 1 is removed to a position exceeding the depth H, the upper pile 1a is connected by welding or the like as shown in FIG. Settle into the ground while rotating 1a. With this construction, the inside of the upper end pile 1a is in a state where no soil is present.

Next, a reinforcing bar 7 is inserted and fixed as a footing connecting member in the head of the upper end pile 1a, and then the hollow pile 1a is filled with concrete 8. This state is shown in FIG.

The example of the embodiment of the pile construction method according to the present invention has been described above with reference to FIGS. 1 to 4. The part may be located below the ground surface.

[0056]

The present invention has been described above, and in particular, since the uppermost hollow pile can be constructed without any soil cement or soil being filled therein, the reinforcing pile or the like is provided in the uppermost hollow pile. Since the footing connecting member can be easily inserted, and a sufficient amount of concrete can be surely filled, the footing connecting member can be securely fixed to the pile head.

Further, since the integrity of the concrete and the hollow pile is not hindered by soil cement or soil remaining in the hollow pile, the footing connecting member can be integrally fixed to the pile head. A footing connection with high proof stress can be formed.

Furthermore, by adopting a steel pipe as the hollow pile, it is possible to remove soil cement and soil without taking into account damage to the inside of the pile. A steel pipe soil cement pile integrated with a steel pipe can be formed.

When a steel pipe is used as a pile, the pile head has a structure in which the outer peripheral portion is a steel pipe, and concrete is filled therein, thereby forming a structure in which the middle-filled steel pipe and concrete are combined, and the horizontal stress is reduced. This results in a structure with a large proof stress.

[Brief description of the drawings]

1 (a) to 1 (h) are views showing an example of a pile construction method according to the present invention in the order of steps.

FIGS. 2A to 2H are views showing an example of a method of constructing a pile according to the present invention in the order of steps.

FIGS. 3A to 3H are views showing an example of a method for constructing a pile according to the present invention in the order of steps.

FIGS. 4A to 4F are views showing an example of a method for constructing a pile according to the present invention in the order of steps.

FIG. 5 is a sectional view of a pile head showing an example of a conventional construction method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hollow pile 1a Upper end pile (hollow pile at the top) 2 Soil cement 3 Excavation / stirring head 4 Rod 5 Root fixing part 6 Inner lid 7 Reinforcing bar (footing connection member) 8 Concrete

Claims (5)

[Claims] In a method for constructing a pile formed by soil cement and a plurality of hollow piles below a footing, there is a soil cement having a depth capable of sinking an uppermost hollow pile to a predetermined position. At the same time, in a state where the hollow piles except the uppermost hollow pile are laid in the soil cement, the soil cement in the hollow pile is moved from the upper end of the hollow pile to a depth corresponding to at least about 10 times the outer diameter of the hollow pile. Then, the uppermost hollow pile is connected, and the uppermost hollow pile is sunk in the soil cement until the pile head remains above the lower end surface of the footing. Pile construction method. 2. A method for constructing a pile formed by soil cement and a plurality of hollow piles below a footing, wherein a hollow pile excluding the uppermost hollow pile is formed in the soil cement while forming the soil cement. The soil cement is further laid down while being connected to each other, and then soil cement is further formed below the hollow pile to at least a depth corresponding to the laid length of the uppermost hollow pile, and the soil cement in the hollow pile is hollowed out. At least approximately 1 mm outside diameter of hollow pile from pile top
The soil cement is removed to a depth corresponding to about 0 times, and then the uppermost hollow pile is connected, and the uppermost hollow pile is connected to the soil cement until the pile head remains above the lower end surface of the footing. Construction method of pile characterized by being settled in. 3. A method for constructing a pile formed by soil cement and a plurality of hollow piles below a footing, wherein the soil cement is formed to a predetermined depth, and then the hollow pile excluding the uppermost hollow pile is removed. If necessary, sunk into the soil cement while connecting to each other, and then remove the soil cement in the hollow pile from the upper end of the hollow pile to a depth corresponding to at least about 10 times the outer diameter of the hollow pile. A method for constructing a pile, comprising connecting an uppermost hollow pile and sinking the uppermost hollow pile into the soil cement to a position where the pile head remains above a lower end surface of the footing. 4. A method of constructing a pile formed by a plurality of hollow piles below a footing, wherein the ground pile is excavated with an auger while connecting the hollow piles except the uppermost hollow pile to each other as necessary. And then further excavating the lower part of the hollow pile with the auger to a depth corresponding to the length in which the uppermost hollow pile is to be built, and forming a stiffening part at the lower end thereof, and then forming The auger is collected and the excavated soil in the hollow pile is removed from the upper end of the hollow pile to a depth corresponding to at least about 10 times the outer diameter of the hollow pile, and then the uppermost hollow pile is connected. A method for constructing a pile, wherein the hollow pile is buried underground to a position where the pile head remains above the lower end surface of the footing. 5. A method of constructing a pile formed by a plurality of hollow piles below a footing, wherein the hollow piles other than the uppermost hollow pile are connected to each other as needed and are erected underground. The soil in the hollow pile is removed from the upper end of the hollow pile to a depth of at least about 10 times the outer diameter of the hollow pile, and then the uppermost hollow pile is connected. A pile construction method, wherein the pile is buried underground to a position that remains above a lower end surface of the footing.