JP2002363980A - Steel pipe pile and pile construction method with drain layer using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steel pipe pile and a pile construction method with a drain layer using the same capable of burying and providing a drain material at outer periphery when constructing the steel pipe pile with a digging spiral blade. SOLUTION: This steel pipe pile 1 is sunk and provided in the ground E by providing the digging spiral blade 3 at outer periphery of a lower end part of a pile body 2 and giving a rotation force and a pressing-in force to the pile body 2. A space forming member 4 capable of forming a space S between the pile body and its peripheral ground E in accordance with sinking is provided at outer periphery of the pile body at an upper position apart from the digging spiral blade 3 by a predetermined interval.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steel pipe pile and a method for constructing a pile with a drain layer using the steel pipe pile. In addition, the present invention relates to a steel pipe pile capable of burying a drain material in a ground around a pile and a method of constructing the pile.

[0002]

2. Description of the Related Art There is known a steel pipe pile which is provided with a drilling spiral blade at a tip end of a pile body and is laid on the ground by applying a rotating force and a pushing force. According to the steel pipe pile with the excavation spiral wing, the earth and sand near the tip of the pile body is lifted upward by the rotation of the excavation spiral wing during construction, and is further pushed out to the side. For this reason, the surrounding ground of the pile body is compacted, and it is possible to settle without excavation.

[0003] By the way, there is known a pile construction method with a drain layer in which a drain material is buried in the ground around a pile body and an effect of preventing liquefaction during an earthquake is expected. However, in this method, a method using the steel pipe pile with the excavation spiral blade has not been proposed.

[0004]

SUMMARY OF THE INVENTION The present invention has been made based on the above technical background, and has the following objects. An object of the present invention is to provide a steel pipe pile capable of burying a drain material on an outer periphery thereof with the construction of a steel pipe pile with an excavation spiral blade, and to provide a pile construction method with a drain layer using the same. .

[0005]

The present invention employs the following means to achieve the above object. That is, the present invention is a steel pipe pile in which a drilling spiral blade is provided on an outer periphery of a lower end portion of a pile body, and the pile body is set in the ground by applying a rotational force and a pushing force to the pile body, and a predetermined distance from the drilling spiral blade. The steel pipe pile is characterized in that a space forming member capable of forming a space between the pile body and its surrounding ground as it is set down is provided on the outer periphery of the pile body at a remote upper position.

More specifically, a plurality of the space forming members are provided at predetermined intervals. The space forming member has a diameter substantially equal to or smaller than that of the excavation spiral blade. The space forming member may be configured by a spiral blade having a winding direction opposite to the excavation spiral blade. The space forming member may be formed of an annular flat plate.

The present invention also relates to a method for constructing a pile with a drain layer using the steel pipe pile, wherein a drain material is disposed on the ground on which the steel pipe pile is laid, so as to surround the pile body. The pile construction method with a drain layer is characterized in that the drain material is wound into the space formed between the pile body and the surrounding ground as the pile is set up to form a drain layer.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side view of a steel pipe pile according to the present invention. The steel pipe pile 1 is provided with a drilling spiral blade 3 on the outer periphery of the lower end portion of the pile body 2. In the illustrated example, the excavation spiral blade 3 has one turn, but may have two or more turns.

At an upper position separated from the excavating spiral blade 3 by a predetermined distance (depending on the target ground, but about 1 to 2 m), a spiral blade 4 as a space forming member is provided on the outer periphery of the pile 2. A plurality of the spiral blades 4 are provided at predetermined intervals (depending on the target ground, but about 1 to 2 m). The winding direction of the plurality of spiral blades 4 is
And the opposite direction. In the illustrated example, the diameter of the spiral blade 4 is the same as the diameter of the drilling spiral blade 3, but may be smaller than the diameter of the drilling spiral blade 3. Each spiral blade 4 has 2
It may be wound or more, and may be a continuous spiral blade without being divided into a plurality. The excavation spiral blade 3
The spiral blade 4 is fixed to the pile 2 by welding or the like.

Next, a method of constructing a pile with a drain layer using the steel pipe pile 1 will be described. 2 and 3 are sectional views showing a construction method. As shown in FIG. 2, a leader 11 of a construction machine 10 such as a pile driver is provided with a driving device 12 that moves along the leader and generates a rotational force and a pushing force. The upper end of the steel pipe pile 1 is connected to the driving device 12, and the lower end is set at the pile core position. On the ground where the steel pipe pile 1 is laid, a drain material 13 is arranged so as to surround the pile body. As the drain material 13, crushed stone, steel slag, and recycled construction materials can be used.

When a rotational force and a pushing force are applied to the steel pipe pile 1 by the driving device 12, the steel pipe pile 1 is embedded so as to be screwed into the ground as shown in FIG. that time,
As shown in FIG. 4, the earth and sand 14 is lifted by the rotation of the excavation spiral blade 3 and is pushed to the side. The lowermost or first-stage spiral blade 4 is located above the lifted earth and sand 14, and since the spiral blade 4 is opposite to the excavation spiral blade 3, the earth and sand may rise further. Instead, a downward pushing force is applied to the earth and sand, so that a space S is formed between the pile body 2 above the first-stage inverted spiral blade 4 and the surrounding ground E.

On the other hand, since the drain material 13 is disposed on the ground as described above, the drain material 13 is involved in the space S with the sinking of the steel pipe pile 1. At this time, since the pile body 2 is provided with a plurality of spiral blades 4 in the direction opposite to the excavation spiral blade 3, the drain material 13 is forcibly pushed into the space S by the rotation of these reverse spiral blades 4. It is.

In this way, the drain material 13 is buried between the pile body and the surrounding ground with the sinking of the steel pipe pile 1, and the drain layer 15 is formed as shown in FIG. 3 (b). Since the drain layer 15 is formed by forcibly pushing the drain material 13 as described above, the drain material 13 is compacted, and the accompanying effect of compacting the surrounding ground can be expected. As a result, the bearing capacity of the pile also increases. Also, the drain layer 15 has a drainage function,
The effect of preventing liquefaction during an earthquake can be expected.

FIG. 5 is a side view showing another embodiment of the steel pipe pile, and FIG. 6 is a sectional view taken along line AA of FIG. In this embodiment, the plurality of space forming members provided on the outer periphery of the pile 2 are formed of the annular flat plate 16. The annular flat plate 16 has the same diameter as the diameter of the excavation spiral blade 3 as in the case of the above embodiment, but may have a smaller diameter than the excavation spiral blade 3.

In the case of the steel pipe pile 1 shown in this embodiment, as shown in FIG. 7, the earth and sand 14 are lifted by the rotation of the excavation spiral blade 3 and pushed out to the side. Above, a space S is formed between the pile body and the surrounding ground E. Then, as the steel pipe pile 1 is set down, the drain material 13 is formed in the space S by the plurality of annular flat plates 16.
And a drain layer is formed.

The present invention can adopt various embodiments, and is not limited to the above embodiments. For example, in each of the above embodiments, the spiral blade 4 and the annular flat plate 1 as space forming members are used.
Although a plurality of 6 are provided, a space can be formed by providing only the first space forming member. However, it is preferable to provide a plurality of space forming members in the second and subsequent stages because they have a function of pushing the drain material into the space while maintaining the size of the space formed by the first stage.

In the above embodiment, only the spiral blade or only the annular flat plate is used as a space forming member in one steel pipe pile, but both the spiral blade and the annular flat plate are alternately arranged in one steel pipe pile. It can be used as follows. Note that the depth range in which the drain layer is formed may be a range in which liquefaction of the ground may occur, and the range in which the space forming member is provided may correspond to this.

[0018]

As described above, according to the present invention, a space is formed between the pile and its surrounding ground along with the sinking in the outer periphery of the pile at an upper position separated from the excavation spiral blade by a predetermined distance. Because it was a steel pipe pile provided with a space forming member that can
A drain layer can be formed by embedding drain material in the space accompanying the subsidence construction, and it can be expected to compact the surrounding ground, prevent liquefaction during an earthquake, and increase the pile support capacity .

[Brief description of the drawings]

FIG. 1 is a side view showing an embodiment of a steel pipe pile according to the present invention.

FIG. 2 is a cross-sectional view showing an embodiment of a pile construction method with a drain layer using the steel pipe pile.

FIG. 3 is a sectional view showing a construction state following FIG. 2;

FIG. 4 is a cross-sectional view showing the behavior of earth and sand near the tip of the pile in the steel pipe pile shown in FIG.

FIG. 5 is a side view showing another embodiment of the steel pipe pile.

FIG. 6 is a sectional view taken along line AA of FIG. 5;

FIG. 7 is a cross-sectional view showing the behavior of earth and sand near the tip of the pile in the steel pipe pile.

[Explanation of symbols]

 1: steel pipe pile 2: pile body 3: excavation spiral blade 4: spiral blade (space forming member) 13: drain material 15: drain layer 16: annular flat plate E: peripheral ground S: space

Claims (6)

[Claims] An excavation spiral blade is provided on an outer periphery of a lower end portion of a pile body, and is a steel pipe pile which is provided on a ground by applying a rotational force and a pushing force to the pile body, wherein the pile body is separated from the excavation spiral blade by a predetermined distance. A steel pipe pile provided with a space forming member capable of forming a space between the pile body and its surrounding ground as the sunk body is set down, on the outer periphery of the pile body at the upper position. 2. The steel pipe pile according to claim 1, wherein a plurality of said space forming members are provided at predetermined intervals. 3. The space forming member having a diameter substantially equal to or smaller than that of the excavation spiral blade.
Or the steel pipe pile according to 2. 4. The steel pipe pile according to claim 1, wherein the space forming member is a spiral blade having a winding direction opposite to that of the excavating spiral blade. 5. The steel pipe pile according to claim 1, wherein said space forming member is an annular flat plate. 6. A method for constructing a pile with a drain layer using a steel pipe pile according to any one of claims 1 to 5, wherein a drain material is surrounded on the ground on which the steel pipe pile is laid so as to surround the pile body. The drain material is rolled into the space formed between the pile body and the surrounding ground with the sinking of the steel pipe pile,
A method for constructing a pile with a drain layer, comprising forming a drain layer.