JP2016108886A - Pile head treatment device, and ground improvement body forming method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pile head treatment device that eliminates a need on scraping work by a backhoe, enhances safety in work, and is likely to yield a high-quality ground improvement body.SOLUTION: A pile head treatment device 20 is formed interchangeably with an excavating agitation device 10 rotated underground by driving force from a base machine, for forming a columnar soil cement ground improvement body underground. The pile head treatment device includes a shaft body 21 fitted on the base machine to rotate underground, and a plurality of cutting blades 22 fitted at a bottom part of the shaft body 21 to extend in a radial direction of the shaft body 21, the plurality of cutting blades cutting a swollen part of uncured soil cement that swells exceeding a prescribed depth, at a head part of the ground improvement body.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a pile head processing apparatus for removing an excess portion that is easily formed on the head of a ground improvement body made of uncured soil cement in a ground improvement method using a ground improvement body, and a related technique.

  At various sites, a ground excavation and agitation device is attached to the base machine, and the excavation and agitation device rotates in the ground to excavate and agitate the ground to a predetermined depth to form a ground improvement body made of soil cement that reaches a predetermined depth. It is used.

  In carrying out this construction method, cement milk which is a material of soil cement is discharged when excavating and stirring the ground using an excavating and stirring device. After the excavating and stirring device reaches a predetermined depth, the excavating and stirring device is pulled up to the ground.

  In this way, the bottom of the columnar ground improvement body can be brought to a predetermined depth, but since the volume of the ground increases due to the discharge of cement milk, the head of the ground improvement body is more than the specified depth. In many cases, surplus portions are formed on the upper side of the ground improvement body. If the surplus part is not noticed, it may be left as it is.

  In short, if the surplus part is left as it is after it has been constructed and a few days have passed, the surplus part will also harden and it will be difficult to remove it unless a task such as chopping is performed. Therefore, a contractor who works carefully should dig the construction site and its surroundings using heavy equipment such as a backhoe by the enforcement date or the next day of the enforcement date, and further surround the surplus part at the tip of the backhoe bucket. Perform the work of rowing.

  However, this has the following problems.

(1) If the operation of rowing at the tip of the bucket is performed, the head of the ground improvement body may be damaged or broken, and the quality of the ground improvement body is likely to deteriorate.
(2) When there is no heavy equipment such as a backhoe on site, no response is possible.
(3) It is inevitable to increase the cost for preparing heavy equipment such as backhoes.
(4) The specified depth is large, and the bucket tip may not reach the specified height and cannot be removed.
(5) If the specified depth exceeds 2 meters, a chief excavator (person who has completed a skill course) is required, and there is a risk of soil collapse.
(6) When a large backhoe is used, the excavation range is widened, so that there is a case where it is not possible to perform the rowing work due to site restrictions.
JP 2007-308924 A

  Accordingly, an object of the present invention is to provide a pile head processing apparatus that eliminates the need for rowing work by a backhoe, has high work safety, and easily obtains a high-quality ground improvement body.

  The pile head processing apparatus according to the first aspect of the present invention is formed to be exchangeable with an excavating and agitating apparatus that rotates in the ground by receiving a driving force from a base machine and forms a columnar ground improvement body made of soil cement in the ground. A pile head processing device, which is mounted on a base machine, is formed in a shaft that rotates in the ground, and at the bottom of the shaft, is raised above a specified depth at the head of the ground improvement body, and is uncured A plurality of cutting edges for cutting an excess portion made of soil cement are provided so as to extend in the radial direction of the shaft body.

  In the pile head processing apparatus according to the second invention, in addition to the first invention, at least one of the excavation stirring blade and the screw is provided on the upper part of the plurality of cutting blades of the shaft body to improve the straightness in the ground. .

  By these structures, the ground improvement body formation method which consists of the following process can be implemented. That is, this method includes a step of attaching a drilling and stirring device to a base machine, rotating the drilling and stirring device in the ground, excavating and stirring the ground to a predetermined depth, and forming a ground improvement body made of soil cement that reaches the predetermined depth; , The excavator agitation device is pulled up to the ground, the excavator agitation device is removed from the base machine, and the pile head processing device having a shaft body and a plurality of cutting blades extending in the radial direction of the shaft body at the bottom of the shaft body is attached to the base machine The process and the pile head processing device are rotated in the ground, and the surplus portion made of uncured soil cement is formed with a plurality of cutting blades, which is formed to rise above the specified depth in the head of the ground improvement body, Removing excess portions.

  As described above, the head of the ground improvement body can be processed only by exchanging the excavation stirring device and the pile head processing device. Therefore, the backhoe is not necessary, and various problems associated with the work using the backhoe can be solved.

  And since the head of a ground improvement body is processed when a plurality of cutting blades rotate in parallel with a level surface, the head of a ground improvement body can be finished smoothly. In other words, the head of the ground improvement body can be finished to a higher quality than when performing the work of rowing by the backhoe.

  As described above, according to the pile head processing apparatus of the present invention, the rowing work by the backhoe is unnecessary, the safety of the work is increased, and the head of the ground improvement body is finished to a high quality. Can do.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side view of a base machine according to an embodiment of the present invention, FIG. 2 (a) is a front view of the excavating and stirring apparatus, and FIG. 2 (b) is a front view of the pile head processing apparatus. .

  As shown in FIG. 1, the base machine 1 travels on the ground G on the site and moves to a position where a ground improvement body is to be formed. The excavating and stirring device 10 is mounted on the lower end portion of the rotating shaft 4 that stands upright and is supported vertically and rotatably by the bearing 3. When the rotational force generated by the drive unit 2 is applied to the rotating shaft 4, the excavation and stirring device 10 can be rotated.

  As shown in FIG. 2A, a connecting portion 4 a is provided at the lower end portion of the rotating shaft 4. A polygonal connecting rod 11a is formed at the upper end of the excavating and stirring device 10, and the connecting rod 11a is inserted into the connecting portion 4a, and a pin (not shown) is inserted into the side pin hole 4b. Thus, the excavating and stirring device 10 is connected to the rotating shaft. The excavating and agitating device 10 forms a columnar ground improvement body 30 (see FIG. 5 and the like) made of soil cement in the ground.

  The present invention is not based on the excavation stirring device 10 itself, and the excavation stirring device 10 can be arbitrarily configured as long as it can excavate and stir the ground. Incidentally, in the example of FIG. 2A, a drilling blade 12 for excavating soil in the ground is provided at the lowermost end of the shaft body 11 formed coaxially with the connecting rod 11a. The co-rotation preventing wing 13 is loosely fitted to the shaft body 11.

  The co-rotation prevention wing 13 hardly rotates in the ground, and as a result, the soil of the portion excavated by the excavation wing 12 and the soil above the co-rotation prevention wing 13 are cut off.

  A stirring blade 14 is provided above the joint body preventing blade 13 of the shaft body 11. Here, the number of the stirring blades 14 and the like can be arbitrarily selected.

  As shown in FIG. 2B, the pile head processing device 20 is formed to be exchangeable with the excavation stirring device 10. From the viewpoint of the base machine 1, it can be said that the pile head processing device 20 and the excavation stirring device 10 are attachments to the connecting portion 4a.

  More specifically, the pile head processing apparatus 20 has a shaft body 21 as a main material in the same manner as the excavation and agitation device 10, and a connection rod 21a having the same shape as the connection rod 11a of the excavation and agitation device 10 is provided at the upper end portion thereof. Yes. On the other hand, at the lower end portion of the shaft body 21, a plurality of cutting portions (see FIG. 5, etc.) that are formed so as to rise above the specified depth at the head of the ground improvement body 30 and are made of uncured soil cement. Are provided so as to extend in the radial direction of the shaft body 21. The lower edge of the cutting edge 22 is a sharp cutting edge 22a. The inclination of the cutting edge 22 with respect to the vertical direction is preferably about 5 to 60 degrees with respect to the vertical direction. Moreover, it is desirable that the material of the cutting edge 22 is a wear-resistant material substantially equivalent to the material of the bucket attached to the backhoe, and boron steel, manganese steel, or the like may be used. For example, those having a Rockwell hardness C scale hrc of about 50 to 56 can be suitably used.

  Therefore, when the connecting portion 4a is pulled up to a certain height above the ground, the excavating and stirring device 10 is removed from the connecting portion 4a as shown in FIG. 2 (a), and instead, as shown in FIG. 2 (b). And the pile head processing apparatus 20 can be attached to the connection part 4a.

  The lower part of the pile head processing apparatus 20 can be variously changed as shown in the first example (FIG. 3A) to the eighth example (FIG. 3H). First, only the straight cutting edge 22 may be provided on the shaft body 21 as in the first example, or the step 22b may be provided on the cutting edge 22 as in the second example. Further, as compared with the first example and the second example, excavation is performed as in the third example (FIG. 3C), the fourth example (FIG. 3D), and the eighth example (FIG. 3H). An appropriate number of stirring blades 24 may be added.

  In addition, when a conical cone portion 23 having a lower apex is provided at the lowermost end portion of the shaft body 21, the descent operation into the ground becomes smooth, but the cone portion 23 is placed on the head of the ground improvement body 30. Can bite in. If this phenomenon is a concern, the cone portion may be omitted as in the fifth example (FIG. 3E). Furthermore, as in the sixth example (FIG. 3 (f)) and the seventh example (FIG. 3 (g)), the screw 25 is provided on the shaft body 21, or the protrusion 26 is added to the excavation stirring blade 24 as appropriate. You can also When the excavation stirring blade 24 and the screw 25 are provided, when the pile head processing apparatus 20 descends or rises in the ground, the resistance of the soil acts on the excavation stirring blade 24 and the screw 25, and the shaft body 24 moves vertically. . That is, it is easy to ensure straightness in the ground, which is preferable.

  Next, each process of the ground improvement body formation method using the above apparatuses is demonstrated, referring FIGS.

  First, as shown in FIG. 4A, the excavation and stirring device 10 is attached to the connecting portion 4a of the rotating shaft 4, and the formation of the ground improvement body 30 is started. That is, as shown in FIG. 4B, the excavating and stirring device 10 is lowered while excavating and stirring the soil in the ground while rotating the rotating shaft 4 in the forward direction (in the direction of the arrow N1). At the same time, cement milk is discharged from the excavating and agitating apparatus 10 to grow a columnar ground improvement body 30 made of soil cement. In this example, the cement milk is discharged while the excavating and stirring apparatus 10 is lowered. However, the cement milk may be discharged only when the excavating and stirring apparatus 10 is raised.

  When the excavation and stirring is advanced as described above, the excavation blade 12 exceeds the specified depth H1, which is the level of the top of the ground improvement body 30 (that is, the ground improvement body 30 should not be provided above the ground improvement body 30). It goes to a predetermined depth H2, which is the level of the bottom of the improved body 30. Then, as shown in FIG. 4 (c), when the excavating blade 12 reaches a predetermined depth H2, as shown in FIG. 4 (d), the rotating shaft 4 is reversely rotated (in the direction of arrow N2) and is once raised.

  Thereafter, as shown in FIG. 5 (a), in order to knead the vicinity of the bottom of the ground improvement body 30, the rotating shaft 4 is rotated forward again and once lowered to a predetermined depth H2. Here, this re-kneading operation may be omitted, but it is desirable to carry out the operation in order to improve the quality of the ground improvement body 30.

  Then, after the re-kneading operation is finished, as shown in FIG. 5 (b), the excavating and stirring apparatus 10 is raised while reversing the rotating shaft 4, and finally, as shown in FIG. 5 (c), the excavating and stirring apparatus 10 To the ground. And as shown in FIG. 2, excavation stirring apparatus 10 is replaced | exchanged for the pile head processing apparatus 20 (FIG.5 (d)). Of course, since the pile head processing described below can be performed before the ground improvement body 30 is hardened, it may be performed one to two days after the excavating and stirring device 10 is pulled up. However, since the ground improvement body 30 is immovable in the ground, it is desirable to carry out continuously with the same base machine 1. Of course, the pile head can also be processed by another compatible base machine.

  As shown in FIG. 5 (d), when the cement milk is discharged into the ground, the moisture in the cement milk may diffuse to the surroundings, but the volume in the excavated area increases. Therefore, in most cases, the surplus portion 31 that rises above the specified height H1 is formed as it is.

  Therefore, as shown in FIG. 6A, the pile head processing device 20 is attached to the rotating shaft 4, and the pile head processing is performed as shown in FIG. 6B while the rotating shaft 4 is rotated forward (in the direction of arrow N1). The device 20 is lowered. Here, the lowering speed of the pile head processing device 20 may be faster above the surplus portion 31, but after the cutting edge 22 contacts the surplus portion 31, the lowering speed is lower than the lowering speed of the excavating and stirring device 10. (Ie slow) is preferred. Then, the excessive part 31 is removed while the cutting blade 22 rotates around the rotation axis 4.

  Then, as shown in FIG. 6C, when the cutting edge 22 reaches the specified depth H1, the rotary shaft 4 is reversed (in the direction of the arrow N2), and as shown in FIG. Raise 20 to the ground. As shown in FIGS. 6C to 6D, the pulling speed may be increased.

  According to the experiment of the present inventor, since the surplus portion 31 is cut by the rotation operation of the cutting blade 22, the head of the ground improvement body 30 after the processing is finished very smoothly and with good quality.

  As is apparent from the above description, according to the present invention, it is easily understood that no heavy machinery such as a backhoe is required, and various problems associated with the rowing work by the backhoe do not occur at all. That is, a high-grade ground improvement body can be obtained by work with high safety, and the practical effect is high.

  The pile head processing apparatus according to the present invention can be suitably used, for example, in the field of ground improvement.

The side view of the base machine in one embodiment of the present invention (A) Front view of excavation and agitation device in one embodiment of the present invention (b) Front view of pile head processing device in one embodiment of the present invention (A) Perspective view showing the lower part of the pile head processing apparatus in the first example of the present invention (b) Perspective view showing the lower part of the pile head processing apparatus in the second example of the present invention (c) In the third example of the present invention The perspective view which shows the lower part of a pile head processing apparatus (d) The perspective view which shows the lower part of the pile head processing apparatus in the 4th example of this invention (e) The perspective view which shows the lower part of the pile head processing apparatus in the 5th example of this invention (F) Perspective view showing the lower part of the pile head processing apparatus in the sixth example of the present invention (g) Perspective view showing the lower part of the pile head processing apparatus in the seventh example of the present invention (h) In the eighth example of the present invention Perspective view showing the lower part of the pile head processing device (A) Process explanatory drawing of the ground improvement body formation method in one embodiment of this invention (b) Process explanatory drawing of the ground improvement body formation method in one embodiment of this invention (c) One embodiment of this invention Process explanatory drawing of the ground improvement body formation method in (d) Process explanatory drawing of the ground improvement body formation method in one embodiment of this invention (A) Process explanatory drawing of the ground improvement body formation method in one embodiment of this invention (b) Process explanatory drawing of the ground improvement body formation method in one embodiment of this invention (c) One embodiment of this invention Process explanatory drawing of the ground improvement body formation method in (d) Process explanatory drawing of the ground improvement body formation method in one embodiment of this invention (A) Process explanatory drawing of the ground improvement body formation method in one embodiment of this invention (b) Process explanatory drawing of the ground improvement body formation method in one embodiment of this invention (c) One embodiment of this invention Process explanatory drawing of the ground improvement body formation method in (d) Process explanatory drawing of the ground improvement body formation method in one embodiment of this invention

DESCRIPTION OF SYMBOLS 1 Base machine 1a Leader 2 Drive part 3 Bearing 4 Rotating shaft 4a Connection part 10 Excavation stirring apparatus 11, 21 Shaft body 11a, 21a Connection rod 12, 14 Stirring blade 13 Joint rotation prevention blade 24 Excavation stirring blade 20 Pile head processing apparatus 22 Cutting edge 23a Cutting edge 22b Step 23 Cone part 25 Screw 26 Projection 30 Ground improvement body 31 Excess part G Ground H1 Specified depth H2 Predetermined depth

Claims (3)

A pile head processing device formed to be exchangeable with an excavation stirring device that rotates in the ground by receiving a driving force from a base machine and forms a columnar ground improvement body made of soil cement in the ground,
A shaft mounted on the base machine and rotating in the ground;
At the bottom of the shaft body, a plurality of cutting blades formed in the head of the ground improvement body so as to rise above a specified depth and cut an excess portion made of uncured soil cement are provided in the radial direction of the shaft body. A pile head processing apparatus characterized by being provided to extend. The pile head processing apparatus according to claim 1, wherein at least one of an excavation stirring blade and a screw is provided on an upper portion of the plurality of cutting blades of the shaft body to improve straightness in the ground. Attaching a drilling and stirring device to the base machine, rotating the drilling and stirring device in the ground, excavating and stirring the ground to a predetermined depth, and forming a ground improvement body made of soil cement to the predetermined depth;
Pulling up the excavation stirring device to the ground, removing the excavation stirring device from the base machine, a pile head processing device having a shaft body and a plurality of cutting blades extending in the radial direction of the shaft body at the bottom of the shaft body, Attaching to the base machine;
The pile head processing device is rotated in the ground, and an excessive portion made of the unhardened soil cement is formed with the plurality of cutting blades, and is formed so as to rise above a specified depth at the head of the ground improvement body. The ground improvement body formation method including the process of removing the said excess part.

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