JPH0799015B2 - Ground improvement agitator and ground improvement method using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stirrer used in a ground improvement method for forming a solidified body having a rectangular cross section in the ground by mixing excavated soil and solidifying material, and ground improvement using the same. It is related to the construction method.

[0002]

2. Description of the Related Art The ground is excavated by a drilling rod to a target depth, and after completion of excavation or at the same time as excavation, the excavated soil and the solidified material discharged from the tip of the excavation rod into the soil are stirred. However, the method of forming solidified bodies such as piles in the ground by mixing the two and curing them as they are is conventionally completed because the mixing is performed only with the stirring blade that rotates around the vertical axis together with the drilling rod. The solidified body has a cylindrical shape or a continuous shape.

The upper structure is constructed on a solid body of this shape, but the solid body has a circular cross section, whereas the bottom surface of the structure is usually rectangular, so that the cross section area of the solid body is small. It is less than the bottom area of the structure (about 80%), and the solidified body does not support the entire bottom surface of the structure. Therefore, in order to fully support the bottom surface, it is necessary to form more than necessary solid bodies over the bottom surface of the structure, which is inefficient,
It is uneconomically supported.

The present invention has been made in view of the actual situation of a conventional solid body formed in a circular shape, and a stirring device for forming a solid body having a cross-sectional shape that efficiently supports a structure, and It is intended to newly propose the used construction method.

[0005]

According to the present invention, an upper stirring blade and a lower stirring blade are provided on the peripheral surface of the rod body connected to the tip of the excavating rod so as to project at a distance from each other in the axial direction. At the height of the middle part, on a plane with respect to the rod body,
While arranging the corner stirring blades that rotate around the horizontal axis at the four corners of the rectangle, between the two corner stirring blades whose rotation axes are collinear among the corner stirring blades at the four corners, An intermediate stirring blade that rotates around a horizontal axis that is orthogonal to the rotation axis of the corner stirring blade is arranged.The corner stirring blade and the intermediate stirring blade are used to stir the four corner positions of the rectangular cross section and the intermediate position. By doing so, a solid body having a rectangular cross-sectional shape is formed as a whole, and a state in which the upper structure is efficiently and completely supported is obtained.

The corner stirring blades are arranged at the four corner positions of the rectangle with respect to the rod body in a state insulated from the rotation of the rod body, rotate about the horizontal axis, and excavate the excavated soil and the solidified material at the four corner positions of the rectangular section. Stirring is performed, and the intermediate stirring blades are also arranged between the opposing corner stirring blades in a state of being insulated from the rotation of the rod body, and rotate about the horizontal axis in the direction orthogonal to the rotation axis of the corner stirring blades. , Complementary stirring of excavated soil and solidified material.

The stirring device includes a rod body connected to the tip of the excavating rod, an upper stirring blade and a lower stirring blade projecting from the circumferential surface of the rod body at a distance from each other in the axial direction, and the above four locations. Corner stirring blades and intermediate stirring blades located between the corner stirring blades, and solidification material is passed through the inside of the drilling rod at the protruding positions of the upper stirring blade and the lower stirring blade on the circumferential surface of the rod body. An upper discharge hole and a lower discharge hole for discharging are discharged.

During excavation of the excavating rod, the solidified material is mainly discharged from the lower discharge hole, and the solidified material is first mixed and mixed with the excavated soil by the lower stirring blade at the position of the lower discharge hole, and this mixture is above it. Are agitated into a rectangular sectional shape by the corner stirring blades and the intermediate stirring blades which are located at the bottom and descend along with the excavation. The once-stirred mixture is mixed again by the upper stirring blade located above.

On the contrary, when the rod body is pulled out, it is mainly discharged from the upper discharge hole, and the solidified material is mixed with the mixture at the time of the excavation by the upper stirring blade at that position, and the corner stirring blade located below the intermediate stirring blade. The mixing is repeated again by the partial stirring blade into a rectangular shape, and further mixed by the lower stirring blade therebelow.

For the construction, the excavating rod equipped with a stirring device is rotated, and the solidified material is discharged from at least the lower discharge hole, and the lower stirring blade and the upper stirring blade stir and mix the excavated soil and the solidified material, and at the same time, at the four corner positions. When the mixture in the middle part is stirred and mixed, the mixture is excavated, and after reaching a predetermined depth, the solidified material is discharged from at least the upper discharge hole, and the upper stirring blade and the lower stirring blade mix the excavated soil and the solidified material again, Simultaneously with the mixing, the drill rod is pulled out while stirring and mixing the mixture at the four corners and the intermediate portion, and the solidified material is hardened as it is to form a prismatic solid body.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings showing an embodiment.

First, the invention according to claim 1 will be described.

As shown in FIG. 2, the stirring device A of the present invention has a rod body 1 connected to the tip side of an excavating rod (not shown), and a circumferential surface of the rod body 1 with a distance from each other in the axial direction. Upper stirring blade 2 and lower stirring blade 3 projecting apart from each other
At the height of the intermediate portion between the upper stirring blade 2 and the lower stirring blade 3, as shown in FIG. 1, in a state in which the rod main body 1 is insulated from the rotation at the four corner positions of the plane on the plane with respect to the rod main body 1. The corner stirring blade 4 which is disposed around the horizontal axis and the corner stirring blades 4 and 4 facing each other are also arranged in a state of being insulated from the rotation of the rod body 1, and the rotation of the corner stirring blade 4 is Intermediate stirring blades 5, 5 rotating around a horizontal axis in a direction orthogonal to the axis
And an upper discharge hole 1a and a lower discharge hole 1b for discharging the solidified material through the inside of the excavating rod at the protruding positions of the upper stirring blade 2 and the lower stirring blade 3 on the peripheral surface of the rod body 1. Then, the excavated soil and the solidified material are agitated at the time of excavating the ground by the excavating rod and at the time of extracting the soil, and are mixed into a rectangular sectional shape.

As shown in FIG. 2, the rod main body 1 has a tubular shape, the inner periphery of which serves as an injection pipe 1c for feeding the solidified material. The hole 1a and the lower discharge hole 1b are opened.

On the outer periphery of the rod body 1, axially movable relative to the rod body 1, each of the upper stirring blades 2 is provided.
The upper housing 6 and the lower housing 7 on which the lower stirring blade 3 is projected are covered. An upper discharge hole 6a continuous to the upper housing 6 at a position corresponding to the upper discharge hole 1a of the rod body 1 is provided at a position corresponding to the upper discharge hole 1a of the lower housing 7.
Lower discharge holes 7a continuous with the lower discharge holes 1b are opened at positions corresponding to the lower discharge holes 1b. Upper discharge hole in the example
1a and the lower discharge hole 1b, and the upper discharge hole 6a and the lower discharge hole 7b are both formed perpendicularly to the axis of the rod body 1, and are arranged in the direction in which the solidified material is discharged toward the hole wall.

The upper stirring blades 2 and the lower stirring blades 3 project from the upper discharge holes 6a and the lower discharge holes 7b of the upper housing 6 and the lower housing 7, respectively. The upper stirring blade 2 is provided in the drilling direction of the lower discharge hole 7b.
When the lower stirring blades 3 face each other, the upper stirring blades 2 and the lower stirring blades 3 also serve to disperse the solidified material discharged from the respective sides into the drilled holes.

The stirrer A of the present invention mainly uses the lower discharge hole 1b when the excavation rod descends, and mainly the upper discharge hole when the excavation rod rises.
The solidified material is discharged from 1a, and the solidified material discharged from the lower discharge hole 1b is discharged by the lower stirring blade 3 at that position and the upper stirring blade 2 that passes through that position after discharging, and also from the upper discharge hole 1a. The solidifying material is also the upper stirring blade 2 at that position.
Then, it is agitated by the lower agitating blade 3 passing after the discharge.

As a result, the solidified material is agitated simultaneously with the progress of the excavation rod, so that the solidified material can be efficiently mixed with the excavated soil both when descending and when ascending.

In the embodiment, the ejection from the upper ejection hole 1a and the ejection from the lower ejection hole 1b are completely separated from each other, and when the ejection is performed, the lower ejection hole 1b is released.
In order to discharge only from the upper discharge hole 1a when rising, the upper housing 6 and the lower housing 7 are circumscribed relative to the rod body 1 so as to be vertically movable relative to each other by a certain stroke, and at the same time, Discharge hole 1a and lower discharge hole 1b
The distance between the upper discharge hole 6a and the lower discharge hole 7b is made larger than the distance between them, and when the excavating rod descends, the upper discharge hole 1a is closed by the upper housing 6 as shown by the solid line in FIG. As shown in, the lower discharge hole 1b is closed by the lower housing 7.

As shown in FIG. 2, the upper housing 6 and the lower housing 7 are connected to each other and circumscribe the rod body 1, and a stopper 8 is provided on the outer peripheral surface of the rod body 1 as shown by a broken line. And a stopper 8 formed on the inner peripheral surface of the upper housing 6 or the lower housing 7.
The longer sliding groove 9 allows relative movement in the axial direction. The difference in length between the sliding groove 9 and the stopper 8 is the stroke of the upper and lower housings 6, 7 with respect to the rod body 1.

FIG. 2 shows the positions of the upper housing 6 and the lower housing 7 when the excavating rod descends. When the excavating rod descends, the upper and lower housings 6 and 7 are relative to the rod body 1 due to the resistance of the soil. And the lower end of the sliding groove 9 is locked to the lower end of the stopper 8 and is fixed to the rod body 1. At this time, as shown in the drawing, the lower discharge hole 7b of the lower housing 7 is the lower discharge hole 1b of the rod body 1.
The upper discharge hole 6a of the upper housing 6 is located above the upper discharge hole 1a, the upper discharge hole 1a is closed by the upper housing 6, and the solidified material can be discharged only from the lower discharge hole 1b.

On the contrary, when the excavation rod is raised, the upper and lower housings 6 and 7 descend relative to the rod body 1 as shown by the chain line in FIG. 3, and the lower housing 7 closes the lower discharge hole 1b. The solidified material is discharged only from the upper discharge holes 1a.

The corner stirring blade 4 and the intermediate stirring blade 5 are connected to a support member 11 fixed to a bearing 10 connected to the outer periphery of the rod body 1 as shown in FIG.
It is supported in a state insulated from rotation.

As shown in FIG. 1, the corner stirring blades 4 are arranged at the four corners of a rectangle centered on the axis of the rod body 1 and rotate about the horizontal axis in the same direction. The intermediate stirring blade 5 is the rotating shaft
4a, 4a are arranged between the two corner stirring blades 4, 4 located on the same line, and rotate about a horizontal axis perpendicular to the rotation axis 4a.

The corner stirring blade 4 and the intermediate stirring blade 5 are bearings 10.
Each rotary shaft is driven by a drive device (not shown) installed in the rod body or installed in the rod body 1 in the vicinity thereof.
4a and 5a rotate and agitate the excavated soil and the solidified material in the vertical plane.

In the illustrated embodiment, the corner stirring blade 4 and the intermediate stirring blade 5 are spirally formed around the rotary shafts 4a, 5a, but the shape is such that the excavated soil and the solidified material are in the vertical plane. It need only be stirrable.

Although the illustrated embodiment shows a single-screw type stirring device A, since this stirring device A is connected in units of excavating rods, it is also applicable to a multi-screw type excavator.

Next, the invention according to claim 2 will be described.

According to the present invention, the excavating rod is rotated up and down by the stirrer A according to claim 1 to stir the excavated soil, the solidified material, and the rectangular cross-section. This is a method of forming the united body S. Soil cement, mortar, or slurry of cement milk or the like is used as the solidifying material.

As described in the above invention, the mixing of the excavated earth and sand and the solidifying material is carried out by rotating the excavating rod provided with the stirring device A, discharging the solidifying material from at least the lower discharge hole 1b of the stirring device A, and The excavated soil and the solidified material are stirred and mixed in the horizontal plane by the stirring blades 2 and the lower stirring blades 3 and, at the same time, the corner stirring blades 4 and the intermediate stirring blades 5 are rotated, thereby the four corner positions of the rectangular cross section and the intermediate position thereof. After excavating the excavated soil and the solidified material in the vertical plane while stirring and mixing, and after the excavating rod, that is, the stirring device A reaches a predetermined depth, the solidified material is discharged again from at least the upper discharge hole 1a and the upper stirring is performed again. Wings 2
And the lower stirring blade 3 is used to stir the mixture in the horizontal plane, and at the same time, the corner stirring blade 4 and the intermediate stirring blade 5 are used to mix the mixture in the vertical plane while pulling out the drilling rod.

Excavation of the ground is carried out by a bit attached to the tip of the stirring device A as usual, and at the same time, stirring of the excavated soil by the upper stirring blade 2 and the lower stirring blade 3 is carried out.

During the excavation of the excavating rod, the solidified material is mainly discharged from the lower discharge hole 7b, and first, the lower stirring blade 3 stirs the excavated soil. The agitated mixture has a rectangular cross section by the corner stirring blades 4 and the intermediate stirring blades 5 descending to that position,
Continue to the bottom of the hole while stirring in the vertical plane. The mixture stirred by the corner stirring blade 4 and the intermediate stirring blade 5 is mixed again by the upper stirring blade 2 descending thereafter.

When the excavation rod is pulled out, the upper discharge hole is mainly used.
The solidified material is discharged from 6a, and the upper stirring blade 2 is placed at that position.
Mixed by. This mixture is again stirred into a rectangular cross section by the corner stirring blade 4 and the intermediate stirring blade 5 that pass after the upper stirring blade 2. The mixture stirred by the corner stirring blade 4 and the intermediate stirring blade 5 is repeatedly mixed by the lower stirring blade 3.

As a result of this one reciprocating excavation and withdrawal, the mixture is molded by the upper stirring blade 2 and the lower stirring blade 3 into a prismatic solidified body S as shown in FIG. FIG. 4 shows a molded state of the solidified body S when the biaxial stirring device A is used.

[0035]

The present invention is as described above, and comprises an upper stirring blade and a lower stirring blade, which are provided on the peripheral surface of the rod body connected to the tip of the excavating rod so as to project at a distance from each other in the axial direction thereof. At the height of the middle part, the corner stirring blades that rotate around the horizontal axis are arranged at four corners on the plane with respect to the rod body, and the rotation axis of the corner stirring blades is placed between the facing corner stirring blades. Since the intermediate stirring blades that rotate around the horizontal axis in the direction orthogonal to are arranged, and these corner stirring blades and the intermediate stirring blades perform stirring at the four corners of the rectangular cross section and their intermediate positions. It is possible to form a solid body having a rectangular cross section and efficiently support the upper structure completely.

[Brief description of drawings]

FIG. 1 is a plan view showing an example of manufacturing a single-screw type stirring device.

FIG. 2 is an elevational view taken along line XX of FIG.

FIG. 3 is an elevational view taken along the line YY of FIG.

FIG. 4 is a perspective view showing a completed state of a solidified body.

[Explanation of symbols]

A ... stirring device, 1 ... rod body, 1a ... upper discharge hole, 1b ... lower discharge hole, 1c ... injection tube, 2 ... upper stirring blade, 3 ... lower stirring blade, 4 ... square Stirring blade, 4a ... rotating shaft, 5 ... intermediate stirring blade, 5a ... rotating shaft, 6 ... upper housing, 6a ... upper discharge hole, 7 ... lower housing,
7b: Lower discharge hole, 8: Stopper, 9: Sliding groove, 10
…… Bearing, 11 …… Supporting member, S …… Solid body.

Claims (2)

[Claims] 1. A device for agitating excavated soil and solidified material at the time of excavating the ground with an excavating rod and withdrawing the mixture to mix them into a rectangular cross-sectional shape, and a rod body connected to the tip of the excavating rod, An upper stirring blade and a lower stirring blade projecting from the circumferential surface of the rod body at a distance from each other in the axial direction of the rod body, and a flat surface with respect to the rod body at a height between the upper stirring blade and the lower stirring blade. The corner stirring blades arranged around the four corners and insulated from the rotation of the rod body and rotating around the horizontal axis, and the corner stirring blades at the four corners, the rotation axes are on the same line 2 Similarly, it is arranged between the individual corner stirring blades so as to be insulated from the rotation of the rod body, and includes an intermediate stirring blade that rotates about a horizontal axis that is orthogonal to the rotation axis of the corner stirring blade. Projection of upper stirring blade and lower stirring blade on the peripheral surface of An agitator for ground improvement, characterized in that an upper discharge hole and a lower discharge hole for discharging the solidified material through the inside of the excavating rod are formed at the position. 2. The excavating rod provided with the stirring device according to claim 1 is rotated to discharge the solidified material from at least the lower discharge hole of the rod body, and the excavated soil and the solidified material are circular in the upper stirring blade and the lower stirring blade. At the same time as stirring to the cross-sectional shape, each corner stirring blade and intermediate stirring blade are rotated to advance the excavated soil and solidified material at the four corner positions of the rod body and the intermediate portion while stirring to advance the drilling rod to a predetermined depth. After reaching, the solidified material is discharged from at least the upper discharge hole, and the excavation rod is pulled out again while stirring the mixture of the solidified material and the excavated soil with the upper stirring blade and the lower stirring blade, the corner stirring blade and the intermediate stirring blade again. ,
Ground improvement method to create a solid body with a rectangular cross section.