JPH08134884A - Ground improvement machine and ground improvement method - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent co-rotation and to mix the soil efficiently and uniformly. [Constitution] Excavation axis 1 that vertically excavates into the ground while rotating.
The excavation blade 2 is fixed to the lower end of the soil, the soil is excavated by the rotation of the excavation blade 2, and the soil is agitated and mixed while supplying the solidifying material. 1
A pair of first stirring shafts 4, 4 that rotate and rotate with the rotation of the excavation shaft 1 are horizontally attached to both sides of the first excavation shaft 1.
A plurality of second stirring shafts 5 and 5 which are perpendicular to the first stirring shaft 4 are fixed to the stirring shaft 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ground improvement machine and a ground improvement method for agitating and mixing soil and a solidifying material in a foundation work or the like to improve the ground into a cylindrical shape.

[0002]

2. Description of the Related Art Conventionally, as such a ground improving machine and a ground improving method, for example, one disclosed in Japanese Patent Publication No. 58-29375 is known. As shown in FIG. 5, this machine has a drilling blade 1 at the lower end of a drilling shaft 101 that vertically descends.
02 is fixed, and stirring blades 103, 103 are fixed to the excavating shaft 101 at intervals in the vertical direction.
A co-rotation preventing device 104, which is composed of a cylindrical body 105 having substantially the same diameter as the excavation diameter and which descends as the excavation shaft 101 descends, is mounted above the excavation blade 102 of FIG.
5, co-rotation preventing blades 106, 106, the tips of which extend to the vicinity of the excavation shaft 101, are fixedly provided on the inner peripheral surface.

Then, the excavation blade 10 is moved by a predetermined excavation mechanism.
2. The excavating shaft 101 to which the stirring blades 103, 103 are fixed is rotated and excavated while supplying the solidifying material into the ground. Therefore, the soil excavated by the excavation blade 102 co-rotates integrally with the excavation blade 102 and the stirring blades 103, 103, but the co-rotation prevention blades 106, 106 of the co-rotation prevention device 104 partially remove the soil. The rotation is stopped, and the soil is agitated and mixed by this.

[0004]

However, a part of the soil that rotates is stopped by the co-rotation preventing blades 106, 106 to prevent the co-rotation preventing blades 106, 106 and the stirring blades 103, 1 from rotating.
With 03, the mixture is stirred and mixed only in the horizontal direction,
In particular, the soil in contact with the stirring blades 103, 103 still rotates together with the stirring blades 103, 103, and it takes a lot of time to uniformly stir and mix the soil and the solidifying material, and there is a problem that work efficiency is poor. There was Therefore, the present invention has been made to solve the above problems, and provides a ground improvement machine and a ground improvement method capable of preventing co-rotation and constantly stirring and mixing the soil and the solidifying material efficiently and uniformly. To aim.

[0005]

In order to achieve the above object, a ground improvement machine according to the present invention has a digging blade fixed to the lower end of a digging shaft that vertically digs into the ground while rotating. In the soil improvement machine that excavates the ground by rotating the excavation blade and also mixes the soil while supplying the solidifying material, the soil is improved on both sides of the excavation axis by the rotation of the excavation axis. In addition, a pair of first stirring shafts that rotate on its axis are horizontally attached, and a plurality of second stirring shafts that are perpendicular to the first stirring shafts are fixed to each of the first stirring shafts.

Alternatively, a digging blade is fixed to the lower end of a digging shaft that vertically descends into the ground while rotating, and the ground is digged by the rotation of the digging blade, and at the same time, the solidifying material is supplied to the soil. In a ground improvement machine configured to stir and mix, the distance between both ends on both sides of the excavation shaft has substantially the same dimension as the excavation blade, and rotates and rotates with the rotation of the excavation shaft. A pair of first stirring shafts are horizontally attached, and a plurality of second stirring shafts that are perpendicular to the first stirring shafts are fixed to each of the first stirring shafts. The tip of is centered on the intersection of the excavation axis and the first stirring axis, and is located on the surface of a sphere whose radius is the distance from the center to the tip of the first stirring axis. .

[0007]

The first stirring shaft rotates in the horizontal plane as the excavation shaft rotates, and at the same time, rotates. Along with such rotational movement of the first stirring shaft, the plurality of second stirring shafts fixed to the second stirring shaft simultaneously rotate within the vertical plane. As a result, the soil rotated in the horizontal direction is also rotated in the vertical direction and agitated in a complicated manner, so that co-rotation is completely prevented. And the second
Due to the rotation of the stirring shaft, a force acts on the soil in the tangential direction of its circular contour, and the direction of these forces always changes with the rotation of each second stirring shaft. The uniform stirring and mixing with and can be performed efficiently in a short time.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the ground improvement machine according to the present invention will be described below with reference to FIGS. An excavation blade 2 having a required length is fixed to the lower end of an excavation shaft 1 formed of a cylindrical body and vertically excavating into the ground while rotating, and a stirring blade is provided above the excavation blade 2. 3 are fixed in a cross shape. The stirring blade 3 is formed to have substantially the same length as the excavation blade 2.

A pair of first stirring shafts 4 and 4 are horizontally provided on both sides of the excavation shaft 1 between the excavation blade 2 and the stirring blade 3. The first stirring shafts 4 and 4 also have substantially the same length as the excavating blade 2, and are provided so as to rotate in the horizontal plane and to be rotatable. Also, each of the first
A plurality of second stirring shafts 5 forming a right angle to the first stirring shafts 4 and 4 are fixed to the stirring shafts 4 and 4 at equal intervals. Each of these second stirring shafts 5 is rotated within the vertical plane as the first stirring shafts 4 and 4 rotate. Further, on the outer peripheral surface of the excavation shaft 1, pipes 6 are connected near the excavation blade 2 at the bottom and the stirring blade 3 at the top, respectively, and jet holes for supplying powder of solidifying material or milk into the soil. 6a and 6b are open.

FIG. 2 is an enlarged cross-sectional view of the essential parts showing the rotating mechanism of the first stirring shafts 4, 4. The first stirring shafts 4 and 4 have their base ends penetrating into the excavation shaft 1 and are axially supported by bearings 7 and 7 and have floating gears 8 fixed to their respective base ends.
And, in the excavation shaft 1, the lower end is the first along the central axis.
A fixed support shaft 9 located substantially at the same position as the stirring shafts 4, 4 is suspended, and a fixed gear 10 with which the floating gears 8, 8 mesh is fixed to the lower end of the fixed support shaft 9. Further, the support shaft 11 of the excavation blade 2 is also provided along the central axis of the excavation shaft 1, and is fixed to the inner peripheral surface of the excavation shaft 1 by the bracket 12.
Further, a drive gear 13 meshing with the floating gears 8 and 8 is fixed to the upper end of the support shaft 11.

Then, as the excavation shaft 1 rotates, the excavation blade 2 rotates and the drive gear 13 also rotates. And both first
The stirring shafts 4, 4 rotate in the horizontal plane, and at the same time, the respective idle gears 8, 8 at the base end thereof rotate between the fixed gear 10 and the drive gear 13, so that both the first stirring shafts 4, 4 are rotated accordingly. Rotates about its central axis, that is, it rotates.

The ground improvement machine according to the present invention has the above-mentioned structure, and its operation will be described below. First, the excavation shaft 1 is rotated at low speed and high torque by a predetermined excavation mechanism (not shown), and at the same time the solidified material is supplied from the lower ejection holes 6a of the excavation shaft 1 through the pipe 6 to the ground. Digging vertically inward.

Therefore, as the excavation shaft 1 rotates, the first stirring shafts 4 and 4 rotate in a horizontal plane and rotate at the same time. Furthermore,
The plurality of second stirring shafts 5 will rotate within the vertical plane.
Therefore, the soil that is horizontally rotated by the first agitation shafts 4 and 4 is also vertically rotated by the plurality of second agitation shafts 5, and the soils are complicatedly mixed. Is completely prevented. Also, due to the rotation of the second stirring shaft 5, a force acts on the soil in the tangential direction of its circular contour, and these forces always change with the rotation of each second stirring shaft 5, so this The uniform stirring and mixing of the soil and the solidifying material can be efficiently performed.
Further, in order to make the mixing of the soil and the solidifying material more uniform, when the excavating shaft 1 is reciprocated, the solidifying material is supplied from the upper ejection port 6b at the time of the backward movement, that is, the ascent.

Further, as shown in FIG. 3 and FIG.
The tip P of the stirring shaft 5 is centered on an intersection O between the central axis of the excavation shaft 1 and the central axes of the first stirring shafts 4 and 4, and a distance D from the intersection O to the tip C of the first stirring shaft 4. Sphere Q with radius
Since the sphere Q is aligned with the inner peripheral surface of the improved cylindrical portion A in the ground, the improved cylindrical portion A
All the soil inside is surely taken into the sphere Q and stirred.

Accordingly, even if the excavating shaft 1 is rotated at a low speed while the solidifying material is supplied, the soil and the solidifying material can be agitated and mixed in a short time, so that a very uniform ground improvement pile is short. Formed in time.

[0016]

As described above, in the soil improving machine and the method for improving the ground according to the present invention, the first stirring shaft is attached to the excavation shaft and rotated in the horizontal plane, and at the same time, the first stirring shaft is rotated. Since the second stirring shaft is fixed to and is rotated in the vertical plane, the soil rotated in the horizontal direction is also rotated in the vertical direction and is agitated in a complicated manner. To be prevented. Further, due to the rotation of the second stirring shaft, a force acts on the soil in the tangential direction of its circular contour, and the direction thereof is constantly changing, so that uniform stirring and mixing of the soil and the solidifying material is efficient in a short time. It has the advantage that it can be done.

Further, in particular, the tip of each second stirring shaft is centered on the intersection of the excavation shaft and the first stirring shaft, and on the surface of the sphere whose radius is the distance from the center to the tip of the first stirring shaft. By positioning it so that the sphere is aligned with the inner peripheral surface of the improved cylindrical part in the ground, all the soil in the cylindrical part to be improved is taken into the sphere, and the entire uniform stirring and mixing is not left. Is possible.

[Brief description of drawings]

FIG. 1 is a perspective view of a main part of a ground improvement machine according to the present invention.

FIG. 2 is a cross-sectional view of a main part of a digging shaft.

FIG. 3 is a vertical sectional view showing a usage state.

FIG. 4 is a sectional view taken along line XX in FIG.

FIG. 5 is a vertical sectional view of a conventional example.

[Explanation of symbols]

 1 excavation shaft 2 excavation blade 4 first stirring shaft 5 second stirring shaft

Claims (3)

[Claims] 1. An excavating blade is fixedly installed at a lower end of an excavating shaft that vertically excavates into the ground while rotating, and the ground is excavated by the rotation of the excavating blade while supplying a solidifying material. In a ground improvement machine adapted to stir and mix soil, a pair of first stirring shafts that rotate and rotate with the rotation of the excavation shaft are horizontally attached to both sides of the excavation shaft, and The first stirring shaft has a plurality of second stirring shafts that are perpendicular to the first stirring shaft.
A ground improvement machine characterized by a fixed stirring shaft. 2. A soil excavation blade is fixed to the lower end of an excavation shaft that vertically descends into the ground while rotating, and the soil is excavated by rotating the excavation blade while supplying solidification material. In the ground improvement machine configured to stir and mix, the distance between both ends of the excavating shaft has substantially the same dimension as the excavating blade on both sides of the excavating shaft, and rotates and rotates with the rotation of the excavating shaft. A pair of first stirring shafts are horizontally attached, and a plurality of second stirring shafts that are perpendicular to the first stirring shafts are fixed to each of the first stirring shafts. The tip of the digging shaft and the first
A ground improvement machine characterized by being located on the surface of a sphere whose center is an intersection with the stirring axis and whose radius is the distance from the center to the tip of the first stirring axis. 3. The excavation blade fixed to the lower end of the excavation shaft is rotated to excavate the ground vertically and in a cylindrical shape, and the solidification material is supplied to the excavation shaft so as to rotate on its axis. Rotating a pair of first stirring shafts in a horizontal plane, and at the same time rotating a second stirring shaft fixed to each of the first stirring shafts at a right angle in a vertical plane;
A soil improvement method that is characterized in that soil that rotates horizontally is also rotated vertically.