JP4437627B2 - Solidification pile construction method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improved solidification pile creation method capable of realizing smooth construction when creating a long solidification pile for improving the ground or a solidification pile for seaming.
[0002]
[Prior art]
One of the ground improvement methods is the solidification pile construction method. For example, as shown in FIG. 4, this solidification pile construction method rotates the rotary shaft 1 with the tip of the mechanical stirring device 10 aligned with the core of the column to be constructed, and radiates to the lower part of the rotary shaft 1. While solidifying material is discharged from the solidifying material discharge pipe port 3 attached to a predetermined position of the rotating shaft 1 in the ground of the rotation region of the one or more stirring blades 2a, 2b provided, and stirring and mixing with the in-situ soil It is a construction method in which the penetration is stopped when the design depth is reached, the discharge is stopped, the rotating shaft 1 is rotated or reversed as it is, and further drawn out into the ground while stirring and mixing to create a columnar body. In FIG. 4, reference numeral 21 denotes an excavation bit.
[0003]
Usually, the solidified material is discharged in the penetration step or discharged in the pulling step, but when it is discharged in the penetration step, the installation position of the solidified material discharge pipe port is equal to or lower than the stirring blade. It is convenient in that it can be at any place, and further, the stirring efficiency of the in-situ soil and the solidified material is good.
[0004]
[Problems to be solved by the invention]
However, in the method in which the solidified material is discharged in the intrusion process, if the solidified pile is created deep into the ground, such as the construction of a long solidified pile of 40 m or more, or the creation of joint solidified piles, The rotating shaft is pulled out after a considerable period of time has elapsed since the beginning of discharge. In this case, there is a problem that the solidification of the first input solidified material may start, and the drawing work becomes difficult.
[0005]
Therefore, the object of the present invention is to create a solidified pile that can realize smooth construction even when creating a solidified pile deep into the ground like the creation of a long solidified pile or the formation of jointed solidified piles. It is to provide a method.
[0006]
[Means for Solving the Problems]
In this situation, as a result of intensive studies, the inventors first discharged the solidified material to the lower part of the solidified pile formation region in the penetration process, and then the remaining upper part in the re-penetration process after drawing. It has been found that, while having the advantage of penetration discharge, the agitating blade can be pulled out before solidifying the charged solidified material, and smooth construction can be realized, and the present invention has been completed. .
[0007]
That is, in the present invention, the solidification material is discharged from the solidification material discharge pipe port attached to a predetermined position of the rotation shaft in the ground of the rotation region of one or more stirring blades provided radially below the rotation shaft, This is a method of creating a solidified pile by stirring and mixing with in-situ soil, and the solidified material is discharged to the lower part of the solidified pile creation area in the penetration process, and then the remaining upper part in the re-penetration process after drawing The construction method of the solidification process pile discharged to a part is provided. By adopting such a configuration, the initially supplied solidified material is, for example, about half the length of the solidified pile length to be created, and is the latter half part of the penetration process. Since it takes only a relatively short time from the time of charging the solidifying material, the stirring blade can be pulled out before the solidifying material is solidified. On the other hand, the remaining part is the upper part of the solidified pile length to be created, for example, about half the length, and if only the remaining part is done by the normal construction method, the creation of a long solidified pile or joint solidification Even when solidified piles are built deep into the ground, such as piles, smooth construction can be realized.
[0008]
Further, according to the present invention, in the re-penetration step, the solidification material is discharged to the lower portion of the remaining upper portion, and then discharged to the remaining upper portion in the re-penetration step after drawing. It provides a method for creating piles. By adopting such a configuration, the solidified material first charged is, for example, about 1/3 of the solidified pile length to be created, and is the latter half of the penetration process. Is a relatively short time from the time of charging the solidifying material, and the stirring blade can be pulled out before the solidifying material is solidified. On the other hand, in the remaining part, first, the solidified material is the length of the solidified pile to be formed, for example, about 1/3 (about half of the remaining part), and the latter part of the re-penetration process. The extraction of the stirring blade in the portion is a relatively short time from the time when the solidification material in the portion is charged, and the stirring blade can be extracted before the solidification material is solidified. Furthermore, if the remaining 1/3 part is carried out by a normal construction method, it is necessary to create a particularly long and long solidified pile with a three-penetration process and to connect the ground part with a height restriction with a high-voltage electric wire etc. Even in the case of creating solidified piles, smooth construction can be realized.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The formation method of the solidification process pile in embodiment of this invention is demonstrated with reference to FIGS. FIG. 1 is a schematic diagram for explaining the steps of the method for producing a solidified pile according to this example. FIG. 2 is a diagram showing the locus of the tip of the rotating shaft in the construction method according to this embodiment. Example of construction, (B) is a construction example of joint solidified pile, FIG. 3 is a diagram showing the locus of the rotating shaft tip in the conventional construction method, (A) is a construction example of a long solidified pile, (B) is It is an example of creation of jointed solidified piles. In FIG. 1, the hatched portions 12 and 13 and the oblique lines attached to the locus in FIGS. 2 and 3 indicate that the solidified material is discharged.
[0010]
As the mechanical stirring construction device used in the method for creating a solidified pile according to the present example, for example, a conventional mechanical stirring construction device as shown in FIG. 4 can be used. The solidified material is discharged from the solidified material discharge pipe port 3 provided at a predetermined position of the rotary shaft 1 in the ground of the rotation region of the one or more stirring blades 2a and 2b provided radially below the rotary shaft 1 The solidified pile is created by stirring and mixing with the in situ soil.
[0011]
Specifically, the rotating shaft 1 can be lifted and lowered freely by a rotary drive machine 7 of the construction facility, has a round pipe shape, and a passage through which a solidifying material flows is passed through the pipe. (Not shown). A plurality of stirring blades 2 are provided at the lower portion of 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 portion on the back side in the rotation direction of the one stirring blade 2 b. One end of the solidified material discharge pipe 3 is a solidified material discharge pipe port 31, and the other end is connected to a passage passing through the rotary shaft 1, and this passage is connected to a ground solidifying material supply facility (not shown). (Illustrated).
[0012]
The solidifying material is not particularly limited, and examples thereof include powdery ground improvement material and cement milk. The powdery ground improvement material is discharged together with air. Further, the rotary shaft 1 may be, for example, a square pipe shape other than the round pipe. The mechanical stirrer may be a single-shaft type rotating shaft connected to the rotary driving machine or may be a two-axis type rotating shaft as shown in FIG.
[0013]
Next, a method for creating a long solidified pile will be described. First, the ground 9 is allowed to penetrate while the rotary shaft 1 is rotated in the normal rotation direction by the rotary drive machine 7. The solidified material is discharged to the lower portion Y of the solidified pile formation area Z in the penetration process. That is, the solidified material is not discharged from the solidified material discharge pipe port 31 from the point A on the ground surface to the point B in the middle of the ground (FIG. 1A). Next, the solidification material is discharged from the point B to the point C, and the in-situ soil 11 and the solidification material are stirred and mixed. The position of point B is not particularly limited and is appropriately determined by solidification pile construction growth, but about half of the solidification pile construction growth is preferable in terms of smooth construction. After completion of the first penetration step, the ground is pulled out while rotating the rotating shaft 1 in the normal direction or the reverse direction (FIG. 1 (B)). Next, after the drawing, the solidified material is discharged to the upper portion X of the solidified pile forming area Z in the re-penetration process (FIG. 1C). That is, the solidified material is discharged from the point E to the point F in the middle of the ground, and the in-situ soil 11 and the solidified material are stirred and mixed. After completion of the second penetration step, the ground is pulled out while rotating the rotating shaft 1 in the normal rotation direction or the reverse rotation direction, and the formation of the solidified pile is completed (FIG. 1D).
[0014]
As shown in FIGS. 3A to 3D, in the conventional method, after a considerable time has elapsed after the solidified material starts to be ejected, the rotating shaft is pulled out, and the first solidified material that has been charged. However, in this example, the solidified material introduced in the first drawing process is about half the length of the solidified pile to be created, for example, Moreover, since it is the latter half part of the penetration step, the extraction of the stirring blade in that part can be done in a relatively short time from the time of charging the solidifying material, and the stirring blade can be extracted before the solidifying material is solidified. In addition, the remaining part created in the second penetration step is the upper part of the solidified pile length, for example, about half the length, and if only the remaining part is carried out by a normal construction method, Even in the creation, smooth construction can be realized.
[0015]
Next, a method for creating a spliced solidified pile will be described. First, the rotary shaft 7 is penetrated while loosening the ground while rotating the rotary shaft 1 in the forward rotation direction. The solidified material is not discharged in the initial penetration process, but is discharged to the lower portion Y of the solidified pile formation area Z in the penetration process after adding the rotating shaft. That is, the solidified material is not discharged from the solidified material discharge pipe port 31 from the H point to the I point in the middle of the ground. The position of the point I is not particularly limited, and is determined as appropriate depending on the length of the first rotating shaft and the length of the second rotating shaft to be added. This is preferable in terms of points. Next, after the addition time has elapsed, the solidified material is discharged from point J to point K. After completion of the first penetration step, the ground is pulled out while rotating the rotary shaft 1 in the forward direction or the reverse direction. Next, after the drawing, the solidified material is discharged to the upper portion X of the solidified pile forming area Z in the re-penetration process. That is, the solidified material is discharged from point O to point P in the middle of the ground. After completion of the second penetration step, the ground is pulled out while rotating the rotary shaft 1 in the normal rotation direction or the reverse rotation direction, thereby completing the formation of the solidified pile.
[0016]
As shown in m to n of FIG. 3 (B), in the conventional method, the rotating shaft is pulled out after a lapse of a considerable time from the start of discharging the solidified material, and the solidified material first introduced. However, in this example, the solidified material introduced in the initial drawing process is about half the length of the solidified pile pile to be created, Since it is a portion after the addition in the penetration step, the stirring blade can be pulled out in this portion in a relatively short time from the time of charging the solidifying material, and the stirring blade can be pulled out before the solidifying material is solidified. In addition, the remaining part created in the second intrusion step is about half the length of the solidified pile length, and if only the remaining part is carried out by a normal construction method, even in the creation of joint solidified piles Smooth construction can be realized.
[0017]
In the present invention, in the re-penetration step after the drawing, the solidified material is discharged to the lower portion in the remaining upper portion, and then discharged to the remaining upper portion in the subsequent re-penetration step. Also good. In this case, the penetration process is repeated three times, so the solidified material is discharged in three parts, but as the input length (solidification treatment pile length formed by discharging the solidified material in one penetration process) Although it does not restrict | limit in particular, It is suitable at the point which can be constructed smoothly that it is set as about 1/3 of each solidification processing pile structure growth. In other words, the solidified material that is initially input is about 1/3 of the length of the solidified pile to be created, and is the latter half of the penetration process. Since a relatively short time is sufficient from the time, the stirring blade can be pulled out before the solidified material is solidified. On the other hand, in the remaining portion, first, the solidified material is the length of the solidified pile to be formed, for example, about 1/3 (about half of the remaining portion), and is the second half of the re-penetration process. The extraction of the stirring blade in the portion is a relatively short time from the second solidification material charging time, and the stirring blade can be extracted before the solidification material is solidified. Furthermore, if the remaining 1/3 part is carried out by a normal construction method, especially in the case of creation of a long solidified pile or a jointed solidified pile having a height restriction with a high-voltage electric wire on the ground surface part, Smooth construction can be realized. Further, in the present invention, in the case of creation of a long long solidified pile or a jointed solidified pile having a height restriction, the penetration process is performed at least 4 degrees, that is, the solidified material is 4 degrees. You may carry out by the method of discharging by dividing into the above.
[0018]
【The invention's effect】
According to the present invention, smooth construction can be realized even when a solidified pile is formed deep into the ground like a long solidified pile or a jointed solidified pile.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic diagram for explaining steps of a method for producing a solidified pile according to the present example.
FIGS. 2A and 2B are diagrams showing a locus of a rotating shaft tip in the construction method of the present embodiment, in which FIG. 2A is an example of creating a long solidified pile, and FIG. 2B is an example of creating a joint solidified pile.
3A and 3B are diagrams showing a locus of a rotating shaft tip in a conventional construction method, in which FIG. 3A is an example of creating a long solidified pile, and FIG. 3B is an example of creating a jointed solidified pile.
FIG. 4 is a diagram showing a tip partial structure of a solidified pile forming apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Rotating shaft 2, 2a, 2b Agitation blade 3 Solidification material discharge pipe 31 Solidification material discharge pipe port 5 Stabilization prevention plate 7 Rotation drive machine 9 Ground 10 Mechanical stirring construction apparatus (solidification processing pile creation apparatus)
11 Excavated ground 12 Solidified pile (initially built pile)
13 Solidified pile (2nd pile)

Claims (2)

The solidification material is discharged from the solidification material discharge pipe port attached to a predetermined position of the rotation shaft into the ground of the rotation region of one or more stirring blades provided radially at the lower part of the rotation shaft, and mixed with the original soil. In this method, the solidified pile is formed, and the solidified material is discharged to the lower part of the solidified pile formation area in the penetration process, and then discharged to the remaining upper part in the re-penetration process after drawing. A method for building a solidified pile characterized by In the re-penetration step after the drawing, the solidified material is discharged to the lower portion in the remaining upper portion, and then discharged to the remaining upper portion in the subsequent re-penetration step after being pulled out. A method for creating a solidified pile according to claim 1.

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