JPH03166417A - Ground improving method and drilling auger to be used - Google Patents

Abstract

PURPOSE:To improve the efficiency of the ground improving work and save the labor by drilling a drilling hole till about a half of the predetermined depth, and thereafter, throwing the solidifying agent, etc. in a drilling hole to form the kneaded material, and repeating this work in order to pile the kneaded material. CONSTITUTION:A drilling auger 3 is equipped with a drilling claw 10. A drilling hole 11 is drilled by the drilling auger 3 till about a half depth of the drilling hole 11, and the digged earth 12 is exhausted. Next, the solidifying agent 13 and a little of the water 14 are thrown to be stirred with the digged earth. Furthermore, the drilling hole 11 is drilled till the predetermined depth, and these stirred mixture is compacted to form the kneaded material 15. In the last step, the digged earth 12 of the upper half of the drilling hole 11 and the solidifying agent 13 and a little of water 14 are thrown down on the kneaded material 15 to be stirred for mixing, and is piled in order from the lower to form the kneaded material 15 evenly in the drilling hole 11. The kneaded material 15 can be thereby formed without exhausting the digged earth 12 of the lower half.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a ground improvement method and an excavating auger used in this method.

[Conventional technology]

As a ground improvement method to strengthen soft ground, etc., there is a method of drilling a hole in the ground and pouring a soil improvement solidification material (hereinafter referred to as solidification material) into the excavated hole to create a cylindrical hardened body. .

There is a slurry method for this, which involves injecting a solidifying material into a slurry and stirring and mixing it to form a hardened material, but this method requires a dedicated solidifying material supply plant and large construction machinery. There is a problem.

On the other hand, there is a so-called fill pile method, which uses an excavating auger to perform excavation, stirring, and compaction, as seen in Japanese Patent Application Laid-Open No. 61-40919.

[Problem to be solved by the invention]

This fill pile construction method uses the rotation of the excavation auger not only to excavate the ground. It has the advantage that it can also be used to stir and mix excavated soil and solidification material, but it is not possible to stir and mix a large amount at once.
The excavated soil is once removed to the ground. At this point, the material must be stirred and mixed and the excavated hole must be backfilled. It requires a large number of workers. moreover. Since this method does not use any water, the problem is that the air generated when the solidification material and excavated soil are stirred and mixed remains in the form of bubbles inside the hardened material, reducing its strength.

This invention solves these problems, and
What is its purpose? Work is labor-saving, and. The present invention provides a ground improvement method in which the created hardened body has high strength, and an excavation auger used therein.

[Means to solve the problem]

In view of the above-mentioned problems, the present invention provides: [1] A ground improvement method comprising the following first to fourth steps.

Activate the excavation auger to excavate approximately half of the set excavation depth, and discharge the excavated soil to the ground. 1st step. Add soil improvement solidification material and a small amount of water as necessary to the excavated hole that was excavated in the 1st step. Drop it. The excavation auger is operated to excavate the remaining half of the set excavation depth, and the excavated soil, soil improvement solidification material, and water are stirred and mixed in the second step.In the second step, the excavated soil, soil improvement solidification material, and water are stirred and mixed. The excavated soil is compacted by operating an excavation auger to form a cylindrical kneaded body. The third step is to place a portion of the excavated soil that was excavated in the first step on top of the kneaded material created in the third step, for soil improvement and solidification. The fourth step [2] involves dropping wood and water, stirring and mixing them by operating an excavation auger, compacting them, and stacking them into a cylindrical kneaded body in several steps [2]. An excavating auger used in the ground improvement method described above, which has a stirring claw attached to a nearby spiral collar.

are provided respectively. [Operation] Through the first step in step (2) above, an excavated hole is formed in the ground to a depth approximately half of the set excavation depth, and the excavated soil at this time is discharged to the ground. Also, due to the second step. The excavated hole is dug to the set depth, and the dropped solidification material, a small amount of water, and the excavated soil are stirred and mixed. moreover. - In the third step, the stirred mixture is compacted and formed into a kneaded body in the excavated hole. Then, in the fourth step, the excavated soil was discharged onto the ground on top of this kneaded material. A solidifying agent, water, etc. are dropped, and these are stirred and mixed to form a kneaded body, and this kneaded body is successively piled M on top of the kneaded body below. When all these steps are completed, a homogeneous kneaded body will be created in the drilled hole. Note that this kneaded material solidifies over time. It becomes a cylindrical hardened body.

Next, if the excavation auger of (1) is used, the agitation claws attached to the auger will more thoroughly and completely stir and mix the excavated soil, solidification material, and water.

〔Example〕

Examples of the present invention will be described below with reference to the drawings. Figure 2 is a side view of an earthmoving machine equipped with an excavation auger used in this construction method, and Figure 3 is a side view of the excavation auger. Use Auger 3. In addition. A digging claw 4 is usually attached to the tip of the digging auger 3. Such an excavation auger 3 is attached to a main beam 6 of an earthmoving machine 5 via a hydraulic motor 7.

By the way, this earth-moving machine 5 is preferably equipped with at least a crawler-type traveling device 8 and a dozer 9 for backfilling excavated soil so that it can work even in narrow places with soft ground. Furthermore, this excavating auger 3 is equipped with a stirring claw 10. This stirring claw 10 has a sharp bottle-shaped main body 10a with a threaded portion 10b etc. formed at the rear end, and has two to three threaded parts on a spiral collar 2 following the digging claw 4 at the tip.
Can be removably installed in several places. The reason why it is made detachable is that it can be removed during normal use.

FIG. 1 is a process diagram of the ground improvement method using such an excavating auger 3. First, the excavating auger 3 is positioned at the point to be excavated, and the hydraulic motor 7 is driven to move the excavating auger 3. Rotate in the forward direction to excavate an excavation hole 11 approximately half of the set excavation depth H into the ground. The excavated soil 12 that comes out at this time is discharged onto the ground by moving the excavation auger 3 up and down while rotating it forward and backward (first step). next. drilling auger 3
The remaining half is excavated by rotating forward and backward and moving up and down to form an excavated hole 11 with a set excavation depth H. A solidifying material 13 and a small amount of water 14 are added to this, if necessary, to form the excavated soil 1.
Stir and mix with 2 (second step). Note that the solidifying material 13 here includes cement-based and lime-based, which are generally commercially available, and may be used. By the way, the reason why the excavated soil 12 can be sufficiently stirred and mixed with the solidifying material 13 and water 14 in the excavated hole 11 without being discharged to the ground in this second step is because the agitating claw 10 is attached to the excavating auger 3. This is because the upper half of the excavated soil l2 is discharged onto the ground, and the amount of excavated soil 12 in the excavated hole 11 is small. Furthermore, drilling hole 1
Since the excavated soil 12 below 1 is clay with a high moisture content, the water 14 to be added here only needs to be added when necessary. Once the excavated soil 12 and solidification material 13 are sufficiently mixed. Next, the drilling auger 3 is rotated forward and backward and moved up and down to compact the stirred mixture and drill the hole 11.
A cylindrical kneaded body 15 is formed in the lower half of the kneaded body (third step). When the third process is completed, a part of the excavated soil 12 that was discharged to the ground in the first process, the solidifying material 13 and the water 14 are removed.
was dropped onto the already prepared kneaded body 15 in the excavated hole 11. The excavation auger 3 is rotated forward and backward and moved up and down to stir and mix and then compact the mixture to form a cylindrical kneaded body 15.
Stack them up. Such operations are repeated one after another, and all the excavated soil 12 is made into a kneaded body 15 and formed into one homogeneous kneaded body 15 in the excavated hole II (fourth step). Note that this kneaded body 15 becomes a hardened body over time and strengthens the ground. By the way, if the work of dropping the excavated soil 12 in the fourth step is performed by the dozer 9 installed in the earth-moving machine 5, it can be done by a small number of people (1 to 2 people) and the work can be done in a short time.

FIG. 4 is a partial cross-sectional view showing the case where the stirring claw 10 is attached to the excavation auger 3.
It is conceivable that the threaded part 10b of the stirring claw 10 is inserted into this mounting hole 16 and fastened with a nant 17. Note that it is desirable to attach about three stirring claws 10 at the same location. moreover. Since the spiral flange 2 is inclined, the rear end of the main body 10a of the stirring claw 10 is formed into an inclined shape along this inclination. A similarly inclined one-shaft 18 may be used for the nant 17 portion. Figure 5 shows the arrangement of the mounting holes 16, but by providing a plurality of holes in advance and selecting their positions, it is possible to mount a plurality of stirring claws in a straight line, an inclined shape, a staggered shape, etc. Can be done. In addition, even if the stirring claw 10 is attached directly to the spiral flange 2 by welding or the like, there is no functional difference.

〔Effect of the invention〕

Since the present invention has been described above, the following effects can be expected.

i) Since the excavated soil 12 in the lower half of the excavated hole 11 is stirred and mixed with the solidification material 13 etc. in this excavated hole 11 without being discharged to the ground, the working time is shortened and labor is saved. It is true. At this time, since the upper half of the excavated soil 12 has been removed to the ground, the vertical stroke of the excavating auger 3 can be increased to shake the excavated soil I2 up and down, thereby achieving perfect stirring and mixing. In addition to allowing air generated at this time to escape, it does not remain in the kneaded body 15 as air bubbles.

ii) Excavated soil 12 and solidified material 13 in the upper half of the excavated hole 11
Since the stirring and mixing of the materials is carried out in small portions at the same time in the excavated hole 11, the stirring and mixing work and the dropping work are labor-saving. Stirring and mixing can also be performed sufficiently.

iii) Since a small amount of water 14 is added when stirring and mixing the excavated soil 12 and the solidification material 13, this water 14 extracts air. No air bubbles remain in the kneaded body 15. iv) The stirring claw 10 of the excavation auger 3 is removable. It can be installed and removed as necessary. Furthermore, since the arrangement of the stirring claws 10 can be selected arbitrarily, it is possible to deal with hard and soft ground in an appropriate amount.

[Brief explanation of the drawing]

Fig. 1 is a process diagram of the ground improvement method according to the present invention. Fig. 2 is a side view of an earth-moving machine equipped with an excavating auger used in this method. Fig. 3 is a side view of the excavating auger. Fig. 4 is a diagram of the excavating auger. Figure 5 is a partial cross-sectional side view when the stirring claw is attached, and Figure 5 is a cross-sectional plan view showing the arrangement of the mounting holes. (Symbols> 2... Spiral flange 3... Excavation auger 10... Stirring claw 1l... Excavation hole 12... Excavation soil 13... Ground improvement solidification material 14... Water 15... Kneaded body

Claims (1)

[Claims] [1] A ground improvement method comprising the following first to fourth steps. Activate the excavation auger (3) to excavate approximately half of the set excavation depth (H), and discharge the excavated soil (12) to the ground in the first step. Improved solidification material (
13) and a small amount of water (14) if necessary,
The second step involves operating the excavation auger (3) to excavate the remaining half of the set excavation depth (H), and stirring and mixing the excavated soil (12), soil improvement solidification material (13), and water (14). In the second process, excavated soil (12), ground improvement solidification material (1
3) and water (14) are stirred and mixed by operating an excavation auger (3) and compacted to form a cylindrical kneaded body (15).The kneaded body (13) created in the third step Part of the excavated soil (12) excavated in the first process, and soil improvement solidification material (13)
and water (14), and the excavating auger (3)
The fourth step [2] is to carry out the operation of stirring and mixing, compacting and stacking into a cylindrical kneaded body (15) in several steps [2], the spiral flange near the tip of the excavation auger (3). (2)
The excavation auger used in the ground improvement method according to claim [1], further comprising a stirring claw (10) attached to the excavation auger.