JP2000345555A - Ground improvement apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a ground improvement apparatus smaller by performing convection mixing, scattering hardener riding the convection, and making mixing and kneading effect higher, also securing sufficient mixing in an up - down direction with slight movement of earth in the up - down direction in the ground thereby performing good ground improvement, and further shortening the length in up - down direction of the mixing apparatus because convection mixing is performed. SOLUTION: In a ground improvement apparatus capable of improving the ground by excavating a bore hole in the ground, a spiral-shaped mixing body 3 is attached to an inner shaft 2 having different turning direction, on the other hand, a mixing body comprising spiral-shaped mixing bodies 4, 7 is attached to attaching bodies 5, 6. And then a mixing body comprising a spiral-shaped mixing body 3 and spiral-shaped mixing bodies 4, 7 are rotated with their turning directions made different and excavation is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soil improvement apparatus capable of improving a ground by excavating a hole in the ground and a ground improvement method using the same.

[0002]

2. Description of the Related Art In order to improve soft ground, a method has been used in which a hole is excavated in the ground, excavated soil and a hardening agent are stirred and kneaded in the hole, and the ground is improved by hardening. . Conventionally, a base machine or the like is used for excavation of the hole, and a plurality of agitating bodies such as a plurality of agitating rods are vertically protruded in the vertical direction of a single axis of rotation, and the plurality of agitating rods are projected. Is rotated together with the rotation of the rotating shaft (together), and while the hardening agent is being sprayed, the excavated soil and the hardening agent are stirred and kneaded as described above to improve the ground by hardening. Have been. In addition, as a rotating shaft for stirring, this is configured as a double shaft of an outer shaft and an inner shaft rotating in opposite directions to each other, and large and small stirring blades having a semicircular arc shape are respectively connected to the lower ends of the inner and outer shafts. Also, there has been proposed a stirring blade structure in a ground improvement device in which the small stirring blade body is positioned inside the large stirring blade body and rotated in opposite directions inside and outside of each other (Japanese Patent Publication No. Hei 3- No. 40166). In addition, examples of patents related to the related ground improvement device include Japanese Patent Application Laid-Open Nos. 1-191717, 6-193047 and 6-193.
059 and JP-A-10-159083.

[0003]

However, a plurality of stirring rods are provided vertically above and below the conventional single-shaft rotating shaft so as to project perpendicularly to the shaft, and the plurality of stirring bars are connected to the rotating shaft. In the ground improvement device that rotates integrally with the rotation, since all of the plurality of stirring rods rotate integrally with the rotating shaft, a so-called co-rotation phenomenon that the excavated soil rotates integrally with the coaxial occurs, and In particular, when the hardening agent is difficult to knead, such as the ground made of viscous soil, the excavated soil will be in a dumpling state wrapping the stirring rod, and it will not be possible to perform stirring kneading at all. There were drawbacks. In addition, the rotating shaft for stirring is configured as a double shaft of an outer shaft and an inner shaft rotating in opposite directions to each other, and semi-circular large and small stirring blades are respectively provided at lower ends of the inner and outer shafts, and The ground improvement device, in which a small stirring blade is positioned inside a large stirring blade and rotated in opposite directions inside and outside each other, has a co-rotation phenomenon and a conglomeration of excavated soil as compared with the above conventional example. However, in this device, large and small stirring blades that rotate in opposite directions are connected continuously to the tip of the lower end of the inner and outer shafts, so that the shearing force is weak and the excavation speed is slow,
Stirring and kneading are apt to be insufficient, and the effect of preventing the co-rotation phenomenon and the formation of dumpling soil is still insufficient. Further, in the conventional example, a plurality of stirring rods are protruded in a direction perpendicular to the rotation axis, and the stirring rod is rotated in a horizontal direction around the rotation axis, or the stirring blade body is also similarly perpendicular to the rotation axis. In any case, it is projected and rotated in the horizontal direction, and in any case, the rotation is performed in the horizontal direction perpendicular to the rotation axis, and the stirring is performed in the horizontal direction. Unless it is moved up and down, sufficient stirring in the vertical direction (depth direction) of the ground cannot be achieved. It is necessary to increase the length of the vertical direction. Furthermore, in the case of the rotary stirring in the horizontal direction as in the conventional example, even if the rotating shafts for stirring are rotated in opposite directions to improve the shearing force, it cannot be utilized, The shearing force is weak, the drilling speed is slow,
Stirring and kneading tend to be insufficient, and the effect of preventing the co-rotation phenomenon and the formation of dumped soil in some cases is still insufficient. An object of the present invention is to provide a technique capable of solving the above-mentioned disadvantages of the related art.

[0004]

SUMMARY OF THE INVENTION The present invention relates to a ground improvement apparatus capable of improving a ground by drilling a hole in the ground, wherein at least two spiral agitators are mounted on inner and outer shafts or mounting bodies having different rotation directions. A ground improvement device characterized by attaching a body, and a ground improvement method capable of improving a ground by drilling a hole in the ground, wherein the rotation direction of at least two spiral stirring bodies is changed. The present invention relates to a ground improvement method characterized by performing excavation.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION

[0006]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a side view of a main part of a ground improvement apparatus showing an embodiment of the present invention, FIG. 2 is an exploded view of the same, and FIG. 3 is a side view of a main part of a ground improvement apparatus showing another embodiment of the present invention. FIG. 4
Is an exploded view of the apparatus, and FIG. 5 is an overall explanatory view of an example of the ground improvement apparatus of the present invention.

Embodiment 1 As shown in FIG. 2 (A), a spiral central stirring body 3 is attached around an inner shaft 2 having a cutting edge 1 at a lower end. As shown in FIG.
The upper end of a spiral-shaped first external stirring body 4 having the same form as that of the middle stirring body 3 is attached to the upper mounting portion 5 of the external stirring body.
Is attached to the lower attachment portion 6 of the external stirring body.
Further, the upper end of the spiral second external stirring body 7 having the same form as the spiral first external stirring body 4 is attached to the upper mounting portion 5 of the external stirring body. The lower end of the external agitator 7 is attached to the lower mounting portion 6 of the external agitator. As shown in FIG. 2B, the first external agitator 4 and the second external agitator 7 are formed in a mirror shape around the central axis of the upper and lower mounting portions 5 and 6 of the external agitator. (Symmetrically) spiral first external stirring body 4 and spiral second external stirring body 7 attached to upper and lower mounting portions 5 and 6 of the external stirring body.
Are integrally configured to rotate in the same rotational direction. The components shown in these exploded views are assembled as shown in FIG. 1, and the inner shaft 2 having the excavation blade 1 at the lower end and the spiral-shaped middle stirring body 2 attached thereto is attached to the upper and lower parts of the outer stirring body. It is attached to the attachment parts 5 and 6 and has a spiral middle stirring body 2 inside, and a spiral first stirring body outside.
A stirrer in a ground improvement device having an external stirrer including the external stirrer 4 and the spiral second external stirrer 7 is configured.

Embodiment 2 FIG. Next, another embodiment of the present invention shown in FIGS. 3 and 4 will be described. In this embodiment, as shown in FIG. 4 (B), the upper end of the spiral first external stirring body 4 is attached to the upper mounting portion 5 of the external stirring body, and the spiral first external stirring body is attached. 4 is attached to the lower attachment portion 6 of the external stirring member, and the upper end of the spiral second external stirring member 7 having the same form as the spiral first external stirring member 4 is externally stirred. Attached to the upper attachment part 5 of the body, and further provided with the second spiral stirring body 7
Is attached to the lower attachment portion 6 of the external stirring member in the same manner as in the first embodiment, except that the lower end portion of the upper attachment portion 5 of the external stirring member extends downward. A different point is that a spiral third external stirring body 8 is attached to the portion. Also, as shown in FIG. 4 (A), a point in which a spiral middle stirring body 3 is attached around an inner shaft 2 having an excavation blade 1 at a lower end is the same as in the first embodiment.
The difference is that the attachment portion 9 of the spiral middle stirring body 3 is attached to the outer periphery of the inner shaft 2. The components shown in these exploded views are assembled as shown in FIG. 3 and have a spiral middle stirring body 2 inside as in the first embodiment, and a spiral first stirring body 2 outside. It has an external stirrer composed of the external stirrer 4 and the spiral second external stirrer 7, and further includes a spiral third external stirrer 8 in addition to the spiral central stirrer 2. A stirrer in the ground improvement device provided inside is constructed.

Next, an example of application of the apparatus will be described with reference to FIG. The stirrer A in the ground improvement apparatus as shown in FIGS.
As shown in (1), it is provided at the lower end of the rotating shaft 10 of the ground improvement device B. The drawing of the stirring device A is partially omitted. The ground improvement device B includes a base machine 11 and a curing agent supply pump 12, as shown in the figure. The base machine 11 may be configured to be movable. The base machine 11 is rotated by the reader 13
0 is supported vertically, and the drive motor interposed between the leader 13 and the rotating shaft 10 rotates the rotating shaft 10 and the excavation blade 1 attached to the tip of the rotating shaft 10 while the leader 13 is rotated.
The rotary shaft 10 is lowered along the shaft to excavate a circular column-shaped excavation hole 15 perpendicular to the ground 14. The rotating shaft 10 is connected to the contra-rotating gear mechanism 16 at its upper part. As shown in FIG. 1, the upper and lower mounting portions 5 of the external agitator corresponding to the outer shaft are provided outside the inner shaft 2.
6, the inner shaft 2 and the upper and lower mounting portions 5, 6 of the external agitator corresponding to the outer shaft are rotated in opposite directions by a double reversing gear mechanism 16 by driving of a drive motor. It has become. The rotation of the inner shaft 2 causes the inner shaft 2
The spiral-shaped central stirring body 3 attached to the inner side rotates inside, while the spiral-shaped first external stirring body 4 attached to the upper and lower attachment portions 5 and 6 of the external stirring body and the spiral-shaped second outer body. An external agitator comprising an agitator 7 rotates in the opposite direction. In the second embodiment in which the third external agitator 8 is attached, the spiral third external agitator 8 also includes the spiral first external agitator 4 and the spiral second external agitator 7. Rotate together in the same direction.

At the time of the ground improvement work, the upper and lower mounting portions 5 and 6 of the inner shaft 2 and the external stirring body and the excavating blade portion 1 are operated by the operation of the drive motor built in the contra-rotating gear mechanism 16.
Rotate and descend. At this time, the spiral first external stirring body 4 and the spiral second external stirring body 7 attached to the upper and lower attachment portions 5 and 6 of the external stirring body are both rotated in the same direction, and the soil for excavation is removed. Works upward. On the other hand, the spiral middle stirring body 3 attached to the inner shaft 2 serves to push down the excavated soil downward. Therefore, convection of the excavated soil occurs, and therefore, compared with the conventional example, the stirring effect is remarkably excellent, the shearing force is greatly improved, the excavation speed is increased, and the stirring and kneading is sufficiently performed. It is also excellent in the effect of preventing the co-rotation phenomenon and the formation of dumped soil. As in the second embodiment, by further attaching the third external stirrer 8, a force that pushes up the excavated soil works inside the spiral middle stirrer 3, and convection is further promoted. It becomes more excellent in the stirring effect and the shearing force.

As shown in FIG. 5, the hardening agent supply pump 12 and the swivel joint 17 in the ground improvement apparatus B are connected to each other via a supply hose 18.
During the ground improvement work, the hardener is supplied from the hardener supply pump 12 through the supply hose 18 to the swivel joint 1.
7, and is further injected from the hardener injection nozzle 19 in the excavating blade 1 via the rotary shaft 10. When a drilling hole 15 having a circular column shape perpendicular to the ground 14 is excavated and the excavating blade 1 reaches a predetermined depth, the rotating shaft 10 is rotated.
The hardener is injected from a hardener injection nozzle 19 at the lower part of the passage through a hardener passage provided inside the, and the hardener and the excavated soil are stirred and kneaded to form a ground improvement portion in the excavation hole 15. To improve the ground. In the present invention, one spiral stirrer is attached to each of the inner shaft and the outer shaft, or one spiral stirrer is attached to each of the attachments instead of the inner shaft or the outer shaft. Or two or more spiral stirrers are attached to each of the inner or outer shafts, or two or more spiral stirrers are attached to each attachment instead of the inner or outer shafts Can be selected as appropriate according to the condition of the ground.

[0012]

As described above, according to the present invention, a plurality of agitating rods are provided vertically in the vertical direction of a conventional one-axis rotating shaft so as to project perpendicularly to the axis, and the plurality of agitating rods are attached to the rotating shaft. The disadvantages of the soil improvement device that rotates integrally with the rotation can be eliminated, and the disadvantages of the conventional device in which large and small stirring blades that rotate in opposite directions are connected continuously to the tips of the lower ends of the inner and outer shafts are also eliminated. Compared to these conventional devices, the shearing force is significantly improved, the co-rotation phenomenon and the effect of preventing the excavated soil from being dumped are significantly improved, and the hardening agent is kneaded like the ground made of viscous soil. Even in difficult cases, good stirring and kneading are performed, and the excavation speed is improved, and the soil improvement work can be completed in a shorter period of time. Even when a powdery hardener is used, good stirring and kneading are performed. It is possible. In the conventional example, since the stirring is performed in the horizontal direction, the stirring in the vertical direction (depth direction) of the ground can be sufficiently performed unless the entire stirring device is moved up and down in the ground. However, according to the ground improvement apparatus according to the present invention, convection agitation is performed, so that it is possible to secure sufficient agitation in the vertical direction without moving the ground too much in the vertical direction, thereby achieving good ground improvement. Since the convection agitation is performed, the length of the agitation device in the up-down direction is short, and the size of the device can be reduced. If it is assumed that both are the same, in the present invention, convection agitation is performed, so that continuous lateral ground improvement can be performed only by lateral movement, whereas in the conventional example, Without horizontal movement, continuous horizontal ground improvement can be performed Furthermore, in the apparatus according to the present invention, convection agitation is performed, so that the curing agent is diffused along with the convection and has a high stirring and kneading effect. There is a drawback that stirring and kneading tend to be inadequate because it is only diffused. Further, in the conventional example, a plurality of stirring rods are protruded in a direction perpendicular to the rotation axis, and the stirring rod is rotated in a horizontal direction around the rotation axis, or the stirring blades are also similarly perpendicular to the rotation axis. In either case, it is projected and rotated in the horizontal direction, or in any case, horizontal rotation orthogonal to the rotation axis is performed, and in this case, the rotation axes for stirring are rotated in opposite directions to each other. Even if the shearing force is improved, it cannot be utilized, the shearing force is weak, the excavation speed is slow, the stirring and kneading are apt to be insufficient, and the co-rotation phenomenon and the prevention of the formation of dumpling soil dumpling. Although the effect was still insufficient in some cases, the present invention can solve these problems.

[Brief description of the drawings]

FIG. 1 is a side view of a main part of a ground improvement device showing an embodiment of the present invention.

FIG. 2 is an exploded view of the same device.

FIG. 3 is a side view of a main part of a ground improvement apparatus showing another embodiment of the present invention.

FIG. 4 is an exploded view of the same device.

FIG. 5 is an overall explanatory view of an example of the ground improvement device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Excavation blade part 2 Inner axis 3 Spiral middle stirring body 4 Spiral first external stirring body 5 Upper mounting part of external stirring body 6 Lower mounting part of external stirring body 7 Spiral second external stirring body 8 Spiral Third External Stirring Body 9 Spiral Middle Stirring Body 3 Attachment Part 10 Ground Improvement Device 11 Base Machine 12 Hardener Supply Pump 13 Leader 14 Ground 15 Drilling Hole 16 Double Reversing Gear Mechanism 17 Swivel Joint 18 Hose 19 Hardener injection nozzle A Stirrer B Ground improvement device

Claims (2)

[Claims] 1. A ground improvement apparatus capable of improving a ground by excavating a hole in the ground, wherein at least two spiral stirring bodies are mounted on inner and outer shafts or mounting bodies having different rotation directions. Soil improvement device. 2. A ground improvement method capable of excavating a hole in the ground to improve the ground, wherein excavation is performed by rotating at least two spiral stirring bodies in different rotation directions. Method.