JP2957491B2 - Construction method of soil column - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soil column construction method for constructing a soil column (also referred to as a pile-shaped hardened body) on the ground using conventional soil (also referred to as local soil).

[0002]

2. Description of the Related Art There are a slurry-type stirring method and a powder-type stirring method as construction methods of a soil column for improving soft ground by using a conventional soil. In the slurry-type stirring method, the ground is excavated with a stirring shaft having stirring blades at the lower end to form a column-shaped stirred soil, and a slurry-like solidified material is pressure-fed from a plant and forcibly injected into the stirred soil through the stirring shaft. In this method, the solidified material and the agitated soil (local soil) are agitated and mixed (for example, see Japanese Patent Publication No. 59-16049). The powder-type stirring method is a method in which a powder-type solidified material is used instead of the slurry-type solidified material in the slurry-type stirring method.

According to each of the stirring methods described above, since the solidified material is forcibly pumped at the same time as the agitated soil is stirred, a dedicated solidified material supply plant facility is required. Since a power source for moving the power source is required and a large occupied area is required, it is often difficult to perform construction on a small land such as a general house.

As a method of solving the above-mentioned disadvantages of the stirring method, there is a method shown in FIG. In FIG. 4, in the conventional method, first, a casing 101 with a screw is positioned on a ground 100 as shown in FIG. 4A, and then, as shown in FIG. 103, the hollow vertical hole 102 is drilled, and then the casing 101 is once pulled out from the vertical hole 102, as shown in FIG. Mixed by etc.,
Next, as shown in (d), the mixed soil 105 is back-filled in the vertical hole 102, and the mixed soil 105 is stirred and mixed by forward and reverse rotation and vertical movement of the casing 101, and then as shown in (e). Then, the mixed soil 105 is compacted by pulling up the casing 101 which has been moved down to the lower end of the vertical hole 102 while reversing it, and then the casing 101 is pulled up above the ground 100 as shown in FIG. Construction is completed.

[0005]

According to the above-mentioned conventional method, as shown in FIG. 4 (c), an excavated soil 103 is mixed with a solidified material 104 on the ground to form a mixed soil 105,
The work of backfilling the mixed soil 105 in the vertical hole 102 is required,
The problem of poor workability remains.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to solve the problem by simply performing stirring and mixing of a solidified material and conventional soil. It is an object of the present invention to provide a method for installing a soil column that can improve the performance.

[0007]

According to a first aspect of the present invention, a solidified material is arranged in a column on the ground, and then the solidified material and the surrounding soil around the solidified material are stirred and mixed. A method for installing a soil column, excavating in the ground
Drilling a vertical hole while drilling the surrounding soil with the casing,
Pour the solidified material into the ground through the excavation casing
Is a construction method of soil column, characterized in that that. According to the method for constructing a soil column according to claim 1, the solidified material is arranged in a column shape on the ground, and the solidified material and the surrounding soil are stirred and mixed, so that the solidified material is solidified into the excavated soil required by the conventional method. The work of adding and mixing the material and the work of backfilling the mixed soil are not required, and the workability can be improved by easily performing the stirring and mixing of the solidified material and the conventional soil.
In addition, while excavating the surrounding soil with a drilling casing on the ground,
Drilling a vertical hole from the periphery of the drilling casing
In order to excavate in advance, stirring of the solidified material and surrounding soil in the subsequent process
Can be easily performed. In addition, vertical holes cannot be maintained below the water table.
If the ground is too rough,
The solidification material can be charged while preventing the collapse of
Material can be accurately left in the surrounding soil, and
It is possible to construct the il column properly without variation.
Wear. In addition, the method for installing a soil column according to claim 1.
According to the method, as set forth in claim 2 of the present invention,
The solidified material to be put into the ground through
No.

According to a third aspect of the present invention, a solidified material is provided on the ground by a column.
Then, the solidified material and the periphery of the solidified material are arranged.
It is a method of installing a soil column that mixes and mixes
Then, a vertical hole was drilled in the ground with a drilling casing,
The solidified material is put into the ground through a drilling casing of
And solidification to be injected into the ground through the excavation casing
Construction of a soil column characterized by containing materials in bags
Is the way . According to the method for constructing a soil column according to claim 3 , the solidified material is arranged in a column shape on the ground.
Since the solidified material and surrounding soil are mixed with stirring, the conventional method is used.
Addition and mixing of the solidified material to the excavated soil required
The work of backfilling the land is unnecessary, and the solidified material
Improve workability by easily performing stirring and mixing
be able to.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. First, an example of an earth auger used in the method for installing the present soil column will be described with reference to FIG. The heavy equipment main body 2 of the earth auger 1 includes a reader 3 and an air compressor 4. The reader 3 is provided with a driving device 5 so as to be able to move up and down. A substantially cylindrical excavating casing 6 is connected to the lower end of the hollow rotary shaft 5a of the driving device 5 in a suspended manner via a separable joint 7. Drive device 5
Is provided with a swivel 8 at its upper end. Swivel 8
Is connected to an air supply hose 4a of the air compressor 4, and compressed air that is pressure-fed through the air supply hose 4a is supplied into the excavation casing 6 via the swivel 8 and the hollow rotary shaft 5a.

The tip (lower end) of the excavating casing 6
The structure of the excavation part will be described with reference to FIG. 3, (a) is a front view,
(B) is a side view, and (c) is a bottom view. A pair of helical blade-shaped digging bits 10 is fixed to the lower end of the digging casing 6. Each excavating bit 10 has a comb-shaped excavating tooth 10a at its lower end edge. The outer peripheral edge of each drill bit 10 is overlaid with superalloy. A pair of strip-shaped stirring blades 11 are fixed slightly above the drill bit 10. Each stirring blade 1
1 is formed with a protruding length larger than the outer diameter of the drill bit 10, and has a comb-shaped drill tooth 11 at its lower end edge.
a. A substantially disk-shaped opening / closing lid 1 capable of opening and closing the lower end opening surface is provided at the lower end of the excavating casing 6.
2 is rotatably mounted via a hinge shaft 13. Excavation teeth 12 a are also provided on the lower surface of the opening / closing lid 12. The open / close lid 12 is in a closed state in a state shown by a solid line in FIGS. (A) and (b), and is in an open state in a two-dot chain line in the figure. The opening / closing side end of the opening / closing lid 12 is provided with a bolt / nut 14 at the lower end of the casing in a closed state.
(Refer to the two-dot chain line in FIG. (C)). In the excavating casing 6, the forward rotation direction indicated by the arrow A in FIG. 3C is the drilling direction, and the reverse rotation direction indicated by the arrow B in the same figure is the lifting direction.

Next, a method for constructing a soil column using the earth auger 1 will be described with reference to an explanatory diagram showing a construction procedure in FIG. First, in (a), the excavation casing 6 is positioned at a predetermined position on the ground 16.
At this time, the opening and closing lid 12 of the excavating casing 6 is not fastened by the bolts and nuts 14 (see FIG. 3C) and can be opened and closed.

Next, in (b), the excavation casing 6 is moved downward while driving the excavation casing 6 through the driving device 5 in the normal direction, thereby removing the surrounding soil (also referred to as conventional soil) 17 around the excavation casing 6. While excavating, the vertical hole 18 of a predetermined depth is excavated. At this time, the vertical hole 18 is excavated by keeping the opening / closing lid 12 closed by the ground 16, and at the same time, the surrounding soil 17 is agitated by the excavation bit 10 and the agitating blade 11.

Next, the joint 7 between the drive unit 5 and the excavating casing 6 is separated, and the upper end surface of the excavating casing 6 is opened as shown in FIG. Then, drilling casing 6
An appropriate number (five bags are shown in the figure) of a powdered solidified material (or a powdered or granular solidified material) 20 in a substantially cylindrical shape in a bag is manually or manually operated using a winch of the heavy equipment body 2. I do. Thus, the solidified material 20 is charged into the excavating casing 6 in a column shape. After the solidified material 20 is charged, a substantially disk-shaped pressure lid 21 for closing the upper end opening of the excavating casing 6 is charged. The pressure lid 21 has an outer diameter smaller than the inner diameter of the excavating casing 6.

Next, in (d), the drive unit 5 and the excavating casing 6 are connected via the joint 7. Subsequently, by driving the air compressor 4, compressed air is supplied into the excavating casing 6 through the air supply hose 4a, the swivel 8, and the like (see FIG. 2), and the pressurizing lid 21 is pressurized. The excavating casing 6 is pulled up while being driven in the reverse direction via. As a result, the opening / closing lid 12 of the excavating casing 6 is opened, and the solidified material 20 is sequentially extruded from the lower end opening of the excavating casing 6 into the conventional soil 17.

When the excavating casing 6 is lifted above the ground 16, the solidified material 20 is left in the surrounding soil 17 in a column shape as shown in FIG. The pressure lid 21 is collected from the soil after the solidification material 20 is completely left.

Next, after opening and closing the lid 12 of the excavating casing 6 with the bolts and nuts 14 (see FIG. 3 (c)) to close it, the excavating casing 6 is driven forward by the driving device 5 again. Move down. Then, as shown in (f), the solidified material 20 and the surrounding soil 17 (also referred to as conventional soil).
Are mixed with stirring to form a mixed soil 22. The bag of the solidified material 20 is pulverized and mixed into the mixed soil 22 by the excavating teeth 10a, 10b, 10c (see FIG. 3) of the excavating bit 10, the stirring blade 11, and the opening / closing lid 12.

When the excavating casing 6 is moved down to the bottom of the vertical hole 18, almost all the solidified material 20 is stirred and mixed with the surrounding soil 17 as shown in FIG. Subsequently, the excavating casing 6 is pulled up through the driving device 5 while being driven in reverse rotation. Thereby, the mixed soil 22 is compacted again while being stirred again. And
When the excavating casing 6 is pulled up above the ground 16 as shown in (h), the construction of the soil column is completed. When the mixed soil 22 solidifies, the ground 16
Inside the soil column is completed.

According to the soil column construction method described above, the solidified material 20 and the surrounding soil 17 are stirred and mixed in a state where the solidified material 20 is arranged in the column shape on the ground 16, so that the excavation required by the conventional method is performed. The operation of adding and mixing the solidified material to the soil and the operation of backfilling the mixed soil are not required, and the solidified material 20
The workability can be improved by easily performing the stirring and mixing of the soil with the surrounding soil (conventional soil) 17.

Further, for pre-drilling periphery of drilling the casing 6, a rear step solidifying material 20 and the surrounding soil (native soil) 1
7 can be easily performed . Further, since the solidified material 20 can be introduced in a state where the surrounding soil 17 is prevented from collapsing by the excavating casing 6, the solidified material 20 can be accurately left in the peripheral soil 17, and the desired soil column does not vary. Appropriate construction is possible. Also, the solidified material 20 is prevented from being collapsed by the excavating casing 6 in the surrounding soil 17.
The fact that the soil column can be charged is effective, for example, in the construction of a soil column on the ground 16 which is highly collapsible such that a vertical hole cannot be maintained below the groundwater level.

Further, since the solidified material 20 can be introduced into the excavating casing 6 without requiring large-scale solidified material supply plant equipment, it is suitable for construction on a small land such as a general house.

Further, since the solidified material 20 charged into the excavating casing 6 is extruded into the soil by compressed air, the solidified material 20 can be reliably left in the soil.

The present invention is not limited to the above embodiment, but can be modified without departing from the scope of the present invention. For example, in the ground 16 where the wall of the vertical hole 18 does not collapse, the vertical hole 18 is cut into a hollow shape without stirring the soil 17 around the vertical hole 18, and the solidified material 20 is put into the vertical hole 18. It is conceivable that the excavation and stirring of the surrounding soil 17 are performed at the same time later. The solidifying material 20
Is not limited to a bag and may be without a bag, and is not limited to a powder and may be granular or muddy. The solidifying material 20 may be added with an additive such as an expanding material or a water reducing agent, which is useful for improving the quality of the improved soil, if desired.

[0023]

According to the soil column construction method of the present invention, the workability can be improved by easily performing the stirring and mixing of the solidified material and the conventional soil.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a procedure of a method for installing a soil column according to an embodiment.

FIG. 2 is a schematic side view showing an earth auger.

FIG. 3 is an explanatory view showing a digging portion of a casing.

FIG. 4 is an explanatory view showing a procedure of a conventional method.

[Explanation of symbols]

 6 Excavation casing 16 Ground 17 Peripheral soil (conventional soil) 18 Vertical hole 20 Solidified material

Claims (3)

(57) [Claims] 1. A method for constructing a soil column in which a solidified material is arranged in a column shape on the ground, and thereafter, the solidified material and surrounding soil around the solidified material are stirred and mixed , and excavation is performed on the ground.
Drilling a vertical hole while drilling the surrounding soil with the casing,
Pour the solidified material into the ground through the excavation casing
Construction method of soil column, characterized in that that. 2. The method for constructing a soil column according to claim 1, wherein the solidification is carried out into a ground through a drilling casing.
A method for constructing a soil column in which the material is contained in a bag . 3. A solidified material is arranged in a column on the ground, and
After that, the solidified material and the surrounding soil around the solidified material are stirred and mixed.
Soil column construction method, excavating in the ground
A vertical hole is excavated by the casing, and the excavated casing is removed.
Through which the solidified material is injected into the ground and
The solidified material to be injected into the ground through
And a method for constructing a soil column.