JP2002235321A - Formation method of hardening treated pile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a formation method of a hardening treated pile capable of reducting the number of wing-cuts and having the excellence in work efficiency. SOLUTION: The formation method of the hardening treated pile is so constituted that a hardener is discharged from a hardener discharge pipe outlet 31 attached to a predetermined position of a rotary shaft 1 in the ground within a range of rotation of one or more stirring wings 2 provided in a radial shape to the lower part of the rotary shaft 1 and that the hardener to be discharged is stirringly mixed with an earth in original position, a position of the hardener discharge pipe outlet 31 is on the circumference (0.71R) dividing a sectional area into two parts based on the sectional area of the hardener treated pile when the hardener discharge pipe outlet 31 has one outlet, and when the hardener discharge pipe outlet 31 has the plural number (n), it is on the circumference dividing each of areas partitioned by the circumference dividing the sectional area into (n).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved method for forming a solidified pile that can reduce the number of times of blade cutting when forming a solidified pile for improving the ground.

[0002]

2. Description of the Related Art One of the methods for improving the ground is a method for forming a solidified pile. In this solidification pile construction method, for example, as shown in FIG. 6, the rotating shaft 16 is rotated by aligning the tip of the mechanical stirring device 11 with the core of the column to be constructed.
6, one or more stirring blades 12a, 12
The solidified material is discharged from the solidified material discharge port 13, 14 or 15 attached to a predetermined position of the rotating shaft 16 into the ground in the rotation region b, and penetrates while stirring and mixing with the in-situ soil. When the depth is reached, the discharge is stopped, and the rotating shaft 16 is rotated or reversed as it is, and is further pulled up into the ground while stirring and mixing to form a columnar body. In FIG. 6, reference numeral 121 denotes a bit for excavation.

In general, when the solidified material is discharged in the penetration process, the solidified material is discharged from one of the solidified material discharge ports 13 and 15 and discharged in the pulling process.
The solidified material is discharged from the discharge port 14. In either case, the position of the solidified material discharge port 13, 14, or 15 is near the rotary shaft 16, or the center of the blade length (sign L) of the stirring blades 12a, 12b (L). L / 2), these positions were determined empirically.

[0004]

However, if the position of the solidified material discharge port is near the rotary shaft 16, the solidified material will be partially discharged to the vicinity of the center of the cross section of the solidified pile, and the solidified material will be discharged. In order to stir uniformly so as to cover the entire cross-sectional area, there is a problem that the number of times of blade cutting increases. When the position of the solidified material discharge port is near the center of the blade length L of the stirring blades 12a and 12b (L / 2), the position of the solidified material discharge port is compared with the position where the solidified material discharge port is near the rotary shaft 16. Then, although the number of times of blade cutting is reduced, the number of times of blade cutting cannot be remarkably reduced, and the problem of construction delay has not been solved.

Accordingly, an object of the present invention is to provide a method for forming a solidified pile which can reduce the number of times of blade cutting and is excellent in construction efficiency.

[0006]

Under such circumstances, the present inventors have conducted intensive studies and as a result, in the method of forming a solidified pile, the position of the solidified material discharge port is determined based on the cross-sectional area of the solidified pile. If the solidified material discharge port is installed at a position half of the area covered by the solidified material discharge port, the solidified material discharged from the solidified material discharge port is uniformly stirred and mixed over the entire cross-sectional area of the solidification treatment pile. Finding that the number of cuts can be reduced,
The present invention has been completed.

[0007] That is, the present invention (1) relates to a method in which one or more agitating blades radially provided below a rotating shaft are provided in the ground in the rotation area.
A method of discharging a solidified material from a solidified material discharge port provided at a predetermined position of a rotating shaft and stirring and mixing with the in-situ soil to form a solidification treatment pile, wherein the position of the solidified material discharge port is ,
On the basis of the cross-sectional area of the solidification treatment pile, when the number of the solidified material discharge port is one, the cross-sectional area is set on a circumference that divides into two, and when the number of the solidified material discharge ports is plural (n), It is an object of the present invention to provide a method of forming a solidified pile, wherein a region divided by a circumference that divides a cross-sectional area into n equal parts is on a circumference that bisects each. By adopting such a configuration, the solidified material can be uniformly discharged over the entire cross-sectional area of the solidified pile, so that the number of times of blade cutting can be reduced. For this reason, the lifting speed of the rotating shaft can be increased, and the time required for forming one solidification treatment pile can be shortened. Further, if the mixing and stirring are performed at the same number of times as the conventional blade cutting, the solidified material is more uniformly mixed with the in-situ soil, so that a high-quality solidified pile having a uniform strength with less variation can be formed.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A mechanical stirring apparatus used in the method for forming a solidified pile according to the present invention is, for example, a conventional one shown in FIG. Can be used. The structure of the tip part of the mechanical stirring construction device used in the method for forming a solidified pile according to the present invention will be described with reference to FIGS. FIG. 1 is a front view of the tip portion, FIG. 2 is a plan view in the case of one solidified material discharge port, FIG. 3 is a plan view of two solidified material discharge ports, and FIG. The plan view in the case of three pipe openings is shown, respectively.

According to the method for forming a solidified pile according to the present invention, the predetermined rotation of the rotary shaft 1 is carried out in the ground in the rotation range of one or more stirring blades 2a, 2b radially provided below the rotary shaft 1 of the construction apparatus. The solidified material is discharged from the solidified material discharge port 31 provided at the position, and is stirred and mixed with the in-situ soil to form a solidified pile.

The rotating shaft 1 is hung up and down and rotatably by a rotary drive of construction equipment, has a round pipe shape, and a passage through which a solidified material flows is passed through the pipe (not shown). ). A plurality of agitating blades 2 are provided below the rotating shaft 1, and a solidified material discharge pipe 3 is provided on the outer periphery of the rotating shaft 1 at the root of the one stirring blade 2 b on the back side in the rotation direction. Further, a solidified material discharge pipe 4 is provided on the outer periphery of the rotating shaft 1 at a root portion on the back side in the rotating direction of another stirring blade 2a located below the rotating shaft 1. One end of each of the solidified material discharge pipes 3 and 4 is a solidified material discharge port 31 and 41, and the other end is connected to a passage passing through the rotary shaft 1, and this passage is connected to a solidified material supply facility on the ground. (Not shown). The opening direction of the solidified material discharge port 31 is the stirring blade direction, that is, even in the radial direction of the solidification treatment pile, and the tip of the solidified material discharge tube 3 is an elbow pipe, and the direction perpendicular to the stirring blade direction. Is also good. In FIG. 1, reference numeral 21 denotes an excavation bit.

The position of the solidified material discharge port 31 is set at the solidified pile.
In the case where the number of the solidified material discharge port is one based on the cross-sectional area of 5,
On a circumference that bisects the cross-sectional area, and the solidified material discharge port is
In the case of a plurality (n), the section is divided by a circumference that divides the cross-sectional area into n equal parts
On the circumference that bisects the region to be divided. Sand
The position of the solidified material discharge port is expressed by the following equation (1); X (n) = ｛R^Two× (1,2,3, ・ ・, 2n-1) / 2n｝^1/2 (1) (where X is a circumference that divides the area of a circle having a radius R into n equal parts)
Shows the radius of ) Is set on an odd-numbered location of X
You. For example, in the case of three (n = 3) solidified material discharge ports,
X (3) = ｛R^Two× (1,2,3,4,5) / 6｝^1/2From, X (3)₁=
(R^Two/ 6)^1/2= 0.41R, X (3)_Two= (R^Two/ 3)
^1/2= 0.58R, X (3)_Three= (R^Two/ 2) ^1/2= 0.7
1R, X (3)_Four= (2R^Two/ 3)^1/2= 0.82R, X
(3)_Five= (5R ^Two/ 6)^1/2= 0.91R
Taking an odd number, the position of the solidified material discharge port 31 is X
(3)₁= 0.41R, X (3)_Three= 0.71R, X (3)_Five= 0.
It is on the circumference of 91R.

More specifically, the position of the solidified material discharge port 31 is, when the number of the solidified material discharge port 31 is one, a solidified pile having a radius R and on the circumference of a radius 0.71R ( In the case where two solidification material discharge ports 31a and 31b are additionally provided, the solidification treatment pile having a radius R is on the circumference of a radius 0.5R and on the circumference of a radius 0.87R (FIG. 2). 3) When the three solidified material discharge ports 31c, 31d, and 31e are provided, a solidified pile having a radius of R, a radius of 0.41R, a radius of 0.71R, and a radius of 0 .91R on the circumference. If the position of the solidified material discharge port 31 is the above position,
Since the area covered by each solidified material discharge port is the same on the basis of the cross-sectional area of the solidified processing pile, the solidified material can be uniformly discharged over the entire cross-sectional area of the solidified processing pile. It should be noted that the position of the solidified material discharge port is not strictly limited to the above position, and may include a position near the position. For example, if within ± 60 mm from the above position, the solidified material is uniformly mixed with the in-situ soil,
A high-quality solidified pile having uniform strength without variation can be created. The diameter of the solidified pile is usually 600 to
2000 mm.

In the case where a plurality of solidified material discharge ports are provided, these may be disposed substantially in the same plane with each other.
For example, in the case of having two solidification material discharge ports, in addition to the form of FIG. When three solidification material discharge ports are provided, in addition to the configuration shown in FIG. 4, a stirring blade is further provided at a right angle to the stirring blade 2b to form a cross-shaped stirring blade in a plan view. The position where the solidification material discharge pipe 3c or 3d is provided may be used. Further, instead of the solidifying agent discharge pipe 3, a solidifying agent discharge pipe 4 may be used, and the solidifying agent discharge pipe port 41 may be set at the above position.

The solidifying material is not particularly limited, and examples thereof include a powdery ground improvement material and cement milk. The powdery ground improvement material is discharged together with air. Also, the rotating shaft 1
May be, for example, a square pipe shape other than the round pipe. The mechanical stirrer may be a single-shaft type having one rotating shaft connected to the rotary driving machine or a two-shaft type having two rotating shafts.

Next, a description will be given of a method for forming a solidified pile using a single stirring device having a single solidified material discharge port as shown in FIGS. First, the ground is loosened and penetrated while the rotating shaft 1 is rotated in the normal rotation direction by the rotary driving machine. At this time, the cement milk is not discharged from the solidified material discharge port 31. When reaching the predetermined depth, the rotating shaft penetration process ends. Next, when pulling out the ground while rotating the rotation axis in the forward or reverse direction, the cement milk is discharged from the cement milk supply facility on the ground from the solidified material discharge port 41, and is stirred and mixed into the ground. The solidification pile 5 is formed. When the rotating shaft 1 penetrates the ground,
Alternatively, the solidified material discharge port 3 is used for both penetration and extraction.
The solidified material may be discharged from 1 and stirred and mixed in the ground.

The solidified pile 5 formed by the above method is
Changes in the degree of mixing of the solidified material in the cross section with respect to the number of times of blade cutting will be described with reference to FIGS. Figure 5 is a solidification piles according to the example of this embodiment, (A) in the case of the blade cutting the small number n ₁ times by rotating shaft, (B) a moderate blade cutting times by rotating shaft n ₂ FIG. 5 is a schematic diagram showing a mixed portion of the in-situ soil and the solidified material in the case of the round by hatching.
When the blade cutting frequency is n ₁ , the solidified material has diffused only to the central portion of the entire cross section of the solidified pile, but has not yet reached the central portion and the peripheral portion. Further, when the blade cutting proceeds and the blade cutting frequency is n ₂ , the solidified material spreads over the entire cross section of the solidified pile, and a uniform mixture is obtained. On the other hand, except for using a conventional stirring device as shown in FIG. 6 and discharging the solidified material from the solidified material discharge port 15,
FIG. 7 shows a case of a solidification-processed pile formed by a similar method. In FIG. 7, (A) shows a case where the number of times of blade cutting by the rotating shaft is n ₁ , (B) shows a case where the number of times of blade cutting by the rotating shaft is medium n ₂ times, and (C) shows a case where the number of blade cutting by the rotating shaft is n _2. in the case of slightly more n ₃ times than moderate cut number of times,
(D) is a schematic view showing the mixing section of the solidified material and the original position soil in the case of the blade cutting times more often n ₄ times by the rotating shaft by hatching. When the blade cutting frequency is n ₁ , the solidified material is diffused only to a small part of the center of the entire cross section of the solidified pile. Blade cutting progresses, and the number of blade cutting is n
_In the case of _two times, the solidified material has diffused into a region surrounded by a circumference that equally divides the entire area. Further blade cutting,
If the blade cutting the number of ₃ times n, hardening material although the prevailing across the cross section of the solidification pile, not in a uniform. Further advances the blade cutting, when the blade cutting the number of ₄ times n, hardening material spreads to the entire cross section of the solidification stakes are and a homogeneous mixture is obtained. In the present embodiment, the solidified material uniformly spreads over the entire cross-sectional area of the solidified pile, whereas the conventional material has a half of the entire cross-sectional area even if the blade cutting frequency n _{2 is the} same. It has spread only to the extent. As described above, according to the present embodiment, the number of times of blade cutting can be greatly reduced as compared with the conventional one.

[0017]

According to the present invention, since the solidified material can be uniformly discharged over the entire cross-sectional area of the solidified pile, the number of times of blade cutting can be reduced. For this reason, the lifting speed of the rotating shaft can be increased, and the time required for forming one solidification treatment pile can be shortened. In addition, if the mixing and stirring are performed at the same number of times as the conventional blade cutting, the solidified material is more uniformly mixed with the in-situ soil, so that a high-quality solidified pile having a uniform strength without variation can be formed.

[Brief description of the drawings]

FIG. 1 is a front view of a tip portion of a stirring device used in a method of forming a solidification pile according to the present embodiment.

FIG. 2 is a plan view of a distal end portion of a stirrer having one solidified material discharge port of the present embodiment.

FIG. 3 is a plan view of a tip end of a stirrer having two solidification material discharge ports of the present example.

FIG. 4 is a plan view of the tip of a stirrer having three solidified material discharge ports in the present example.

FIG. 5 is a schematic diagram illustrating the degree of mixing of the in-situ soil and the solidified material with respect to the number of blade cutting times of the rotating shaft in the solidification processing pile according to the present embodiment.

FIG. 6 is a front view of a tip portion of a stirrer used in a conventional method for forming a solidification pile.

FIG. 7 is a schematic diagram illustrating the degree of mixing of the in-situ soil and the solidified material with respect to the number of blade cuts of the rotating shaft in the solidification processing pile according to the conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotation shaft 2, 2a, 2b Stirring blade 3, 3a-3e, 4 Solidification material discharge pipe 5 Solidification processing pile 21 Drilling bit 31, 31a-31e, 41 Solidification material discharge port

Claims (4)

[Claims] 1. A solidified material is discharged from a solidified material discharge pipe port provided at a predetermined position of a rotating shaft into the ground in a rotating region of one or more stirring blades radially provided below a rotating shaft, and A method for forming a solidification treatment pile by stirring and mixing with the soil, wherein the position of the solidification material discharge port is based on the cross-sectional area of the solidification treatment pile, and the solidification material discharge port is one. In the case where the cross-sectional area is on a circumference that bisects, and when the number of the solidification material discharge ports is plural (n), the circumference that divides the cross-sectional area into n equal parts is a circumference that bisects each. A method for forming a solidified pile, comprising: 2. The solidification material discharge port is located on a circumference of 0.71R in a solidification treatment pile having a radius of R when the solidification material discharge port is one. A method for forming a solidified pile according to claim 1. 3. The position of the solidified material discharge port is, when there are two solidified material discharge ports, a solidified pile having a radius R, a circle having a radius of 0.5R and a circle having a radius of 0.87R. The method according to claim 1, wherein the pile is on the periphery. 4. The position of the solidified material discharge port is, when there are three solidified material discharge ports, a solidified pile having a radius R, a circle having a radius of 0.41R and a circle having a radius of 0.71R. 2. The method according to claim 1, wherein the pile is on a circumference and a circumference with a radius of 0.91R.