JP5247289B2 - Rotating embedding method of bladed pile - Google Patents

Description

  The present invention relates to a method for rotating and embedding a bladed pile that supports a lower part of a building.

  Conventionally, there are several methods for embedding piles (see, for example, Patent Document 1). In Patent Document 1, a steel pipe pile with a tip blade with a tip blade is rotated and buried perpendicularly to the ground. A pile buried in this way is a vertical pile.

  Moreover, after embedding a steel pipe pile with a tip blade | pipe vertically, there exists a method which inject | pours a solidification material into a front-end | tip part and reinforces the drawing strength of a vertical-pile front-end | tip part (for example, refer patent document 2).

JP-A-2005-240395 JP2007-255108A

  In recent years, various seismic reinforcement works have been carried out in the construction field as earthquake-resistant reinforcement works are becoming popular. However, in order to effectively suppress the horizontal displacement of the pile head using a conventional vertical pile, it is necessary to increase the cross-sectional area of the pile in order to increase the horizontal rigidity of the vertical pile.・ Construction was difficult.

  An object of the present invention is to embed a bladed pile on the ground so that horizontal displacement of the pile head can be suppressed economically.

  The method of the present invention for achieving the above object is as follows.

A method of rotating and embedding a spiral bladed pile, wherein a mixing / replacement step of mixing or replacing soil and solidified material at a desired position in the ground excavated vertically from the ground part , and the bladed pile Inclining step to incline to a desired embedding angle, and confirming the embedding direction of the bladed pile until the tip of the bladed pile reaches the mixture or replacement produced by the mixing / replacement step. And a burying step of burying the ground in the ground.

  As described above, if the bladed pile is inclined and then embedded in the ground, the bladed pile remains inclined in the ground. Then, the horizontal force applied to the pile head is separated into a horizontal component and a pile axial direction component (pushing force or pulling force), and a part of the horizontal force applied to the pile head is borne as a pile axial direction component. For this reason, the pile with blades embedded in an inclined state can suppress horizontal displacement of the pile head relative to the horizontal force according to the embedded angle. Further, the pile axial strength (indentation strength and pullout strength) is increased by integrating the improved body or solidified body at the tip of the bladed pile. Since there is a blade at the tip and the blade is held by an improved or solidified body, and the anchor effect of the tip blade can be expected, the force of the pile axial direction component (push-in force or pull-out force) due to vertical load such as building weight and horizontal force Force). As a result, the yield strength against the horizontal force of the pile head is increased.

  A method for burying the pile 1 will be described with reference to FIG. FIG. 1 is an explanatory view of a method for burying piles, wherein (a) is an explanatory view of a mixing / replacement process, and (b) is an explanatory view of an embedment process.

  First, before the pile 1 is embedded in the ground F, the soil and the solidified material at a desired position in the ground are mixed or replaced <mixing / replacement step>. In the mixing step, as shown in FIG. 1 (a), first, solidified material such as cement milk is simultaneously injected while excavating the ground G vertically from the ground part by the excavating auger D attached to the construction machine M. And stirring and mixing while filling. This completes the mixing process and produces a mixture. Further, in the replacement step, as shown in FIG. 1A, first, the ground G is excavated vertically from the ground portion by the excavating auger D attached to the construction machine M. As a result, a hole H is obtained. And as shown in FIG.1 (b), solidification materials, such as cement, are inject | poured and filled with respect to the hole H obtained by this. Thereby, the substitution step is completed and a substitution product is generated. In addition, the above-mentioned desired position is a position where the pile tip 1a reaches when the burying of the pile 1 is completed. In addition, as described above, the mixture in the present embodiment is cured to become an improved body over time, and the substitute body is cured to become a solidified body over time.

  Next, piles are built. That is, as shown in FIG. 1B, the pile 1 is caught by the construction machine M, and the pile 1 is set according to the pile core O on the ground G. At this time, the pile 1 is in a state in which the pile tip 1a is directed to the pile core O, and is inclined from the vertical direction by a desired burying angle θ <inclination process>. When the pile tip 1 a is set with respect to the pile core O, the pile 1 is fixed by the anti-vibration device 2. In addition, the pile 1 of this embodiment is a pile with a tip blade | wing, and the spiral tip blade | wing 1b is attached to the pile side surface of the pile tip 1a.

  Next, while confirming the burying angle θ and the burying direction of the pile 1, the pile 1 is penetrated into the ground F and buried until the pile tip 1 a of the pile 1 reaches the mixture or the replacement body C <embedding process>. More specifically, when it is first confirmed that the pile 1 has a desired burying angle θ, the pile head 1c of the pile 1 is fixed to the cap 1d of the construction machine M. And the pile 1 rotates by rotating this cap 1d (forward rotation). The pile 1 rotated in this way penetrates into the ground F by the propulsive force of the tip blade 1b arranged at the pile tip 1a.

  When the pile 1 is buried to a desired depth at which the tip 1a of the pile 1 reaches the mixture or the replacement body C, the cap 1d of the construction machine M attached to the pile head 1c of the pile 1 is reversely rotated, and the cap 1d Is removed from the pile head 1c. In this way, the pile 1 is embedded in the ground F at a desired burying angle θ, and the burying operation is completed. Thereafter, the mixture or the substitute body is cured as time passes, and becomes an improved body or a solidified body, and is integrated with the tip 1 a of the pile 1.

  In the above-described tilting process, the desired burying angle θ for tilting the pile 1 is 15 ° ≦ θ ≦ 60 °, and the angle is determined according to the application and the ground condition. In general, the greater the desired embedding angle θ, the smaller the horizontal displacement of the pile head 1c with respect to the horizontal force.

  From the viewpoint of effectively suppressing the horizontal displacement, 15 ° ≦ θ, and from the viewpoint of workability, θ ≦ 60 °.

  Next, suppression of horizontal displacement of the pile head 1c of the pile 1 embedded by the above-described method will be described. FIG. 2 is a diagram for explaining the horizontal displacement and bending moment with respect to the horizontal force of the diagonal pile of this embodiment and the conventional vertical pile, (a) is a diagram in which the pile 1 of this embodiment is embedded in the ground, ) Is a diagram in which a conventional vertical pile 100 is embedded in the ground. Both figures show the horizontal displacement distribution and bending moment distribution along with the state of the pile.

  The pile 1 in the present embodiment having the tip blade 1b embedded in the ground F is embedded in a state in which the pile 1 is not perpendicular to the ground G but inclined. For this reason, as shown in FIG. 2A, when the horizontal force acts on the pile head 1c, the horizontal force and the pile axial direction component (pushing force or pulling force) are caused by the inclination of the pile 1. To be distributed. Thus, the horizontal displacement of the pile head 1c of the pile 1 can be suppressed by bearing a part of the horizontal force applied to the pile head as a pile axial direction component.

  Here, in addition to the force of the pile axial direction component consisting of vertical load such as building weight, the pile 1 axial force due to the horizontal force (pushing force or pulling force) is newly applied to the pile 1. The pile 1 of this embodiment has a tip blade 1b. Thereby, since the anchor effect of the front-end | tip blade | wing 1b can also be anticipated, it can resist the force (push-in force or drawing-out force) of the pile axial direction component by vertical load and horizontal force, such as a building weight. Due to this action, the proof stress can be improved against the horizontal force acting on the pile head 1c. The number and size of the blades can be appropriately set according to the required yield strength. For example, you may arrange | position a blade | wing to the pile 1 besides a front-end | tip part. When arranging the blades, it is preferable to attach the blades at equal intervals.

  Further, the tip blade 1b reaches the improved body or solidified body C. Thus, when the front-end | tip blade | blade 1b of the pile 1 is integrated with the improved body or the solidified body C, a pile axial direction yield strength is increased and the yield strength with respect to a horizontal force is improved more. In addition, when there are a plurality of blades, a plurality of holes H in which the improved bodies or solidified bodies C are disposed are formed according to the number of the blades. Or you may form the hole H of the diameter so that all the some blade | wings may be buried.

  Conventionally, the vertical pile 100 is used as shown in FIG. In this case, when a horizontal force acts on the pile head in the vertical pile 100, the horizontal force becomes a shearing force of the pile and a bending moment also increases. On the other hand, in the pile 1 of this embodiment, although the pile head axial force in the pile head 1c becomes large compared with the vertical pile 100, a pile head shear force, a displacement, and a bending moment can be made small. .

  In the above-described embodiment, only one pile 1 is embedded, but the present invention is not limited to this. That is, by horizontally burying a plurality of piles 1 in the ground F, the horizontal displacement of the pile head can be further suppressed. This will be described. FIG. 3 is a diagram showing a state in which two piles 1 are embedded in the ground.

  As shown in FIG. 3, after performing the above-described tilting process and the burying process, the work is performed again from the adjacent position. Here, in this example, the desired embedding angles in the plurality of tilting steps are the same, the desired embedding directions are changed by 180 degrees when viewed from above, and the soil and the solidified material at the tip of the pile 1 are used. Mixed or substituted. If comprised in this way, compared with the case where only one pile is embed | buried, a horizontal displacement can further be suppressed and a horizontal displacement can be suppressed further by combining the pile head of each pile. Moreover, one pile 1 demonstrates the yield strength which opposes a pile axial direction pushing force, the other pile exhibits the yield strength which opposes a pile axial direction pull-out force, and with respect to the horizontal force which acts on the pile head 1c complementarily. Yield strength can be demonstrated. In this example, the desired embedding angle is the same, but the present invention is not necessarily limited to this. The desired embedding angle can be appropriately changed according to the force expected to be generated.

  In the embodiment, one or two piles 1 are used, but three or more may be used as shown in FIG. FIG. 4 is a top view showing the structure of the combined pile 4 of the three piles 1. In the combination pile 4 shown in FIG. 4, the above-mentioned inclination process and embedding process were repeated 3 times from the near position on the ground, and each desired embedding angle in several inclination processes was comprised as the same. Each embedding direction was different by 120 degrees, and the soil at the tip of the pile 1 was mixed or replaced with a solidified material. By doing in this way, the yield strength of the pile head 1c can be improved, and horizontal displacement can be suppressed even when a horizontal force acts on the pile head 1c from any direction as viewed from above. In this example, the desired burying direction is changed by 120 degrees when viewed from above and the burying angle is the same, but this is not necessarily limited thereto. The embedding direction and the embedding angle can be changed as appropriate according to the force expected to occur.

  The present invention can be used in a method of burying a pile that supports a lower part of a building.

Explanatory drawing of the embedding method of the pile 1. FIG. The figure explaining the horizontal displacement and bending moment with respect to the horizontal force of the diagonal pile of this embodiment, and the conventional vertical pile. The figure which shows the state which laid two piles 1 in the ground. The top view which shows the structure of the combination of the three piles 1. FIG.

Explanation of symbols

C: Improved product (mixture) or solidified product (substitute product)
D ... Auger for excavation F ... Ground G ... Ground H ... Hole M ... Construction machine O ... Pile core 1 ... Pile 1a ... Pile tip 1b ... Tip blade 1c ... Pile head 1d ... Cap 2 ... Anti-rest device 3 ... Leader 4 ... Combination pile 10 ... Bar-shaped member

Claims (1)

A method of rotating and embedding a spiral bladed pile,
A mixing / replacement step for mixing or replacing the soil and the solidified material at a desired position in the ground excavated vertically from the ground part ;
An inclination step of inclining the bladed pile to a desired burying angle;
Embedding step of burying the bladed pile on the ground until the tip of the bladed pile reaches the mixture or replacement produced by the mixing / replacement step while confirming the burying direction of the bladed pile,
A rotary burying method of a bladed pile characterized by comprising:

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