JPH07173828A - Soil improving device - Google Patents

Abstract

PURPOSE:To reinforce bearing force of improved soil and to promote reliability of soil improving work by forwardly rotating an excavation edge to move excavated soil upward, and reversely rotating the excavation edge to move soil improving agants downward. CONSTITUTION:An excavation shaft 4 is formed in a double shaft of an external shaft 7 and an internal shaft 8 capable of forward and reverse by rotating rotating each other in the reverse direction. After that, an outside stirring wing body 10 and an inside stirring wing body 11 are respectively fixed to one or the other of the external shaft 7 and internal shaft 8, and the inside and outside stirring wing bodies 11 and 10 are rotated each other in the reverse direction. A flow-out hole 13 of soil improving agants is provided to the same level position as that of an excavated edge 6, the excavation edge 6 is forwardly rotated to move excavated soil upward, and the excavation edge 6 is reversely rotated to move the soil improving agants downward of the excavation edge. According to the constitution, the soil improving agants can be sent to the lowest part of an excavated hole bearing very much bearing force.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ground improvement device.

[0002]

2. Description of the Related Art Conventionally, as one method for improving soft ground, a vertical hole is formed in the ground by a base machine or the like, and the excavated soil and the ground improvement agent are agitated and kneaded in the vertical hole to excavate the soil. A method of hardening the ground by an improving agent to improve the ground is adopted, and a stirring rod or the like protruding from the excavation shaft is used for stirring and kneading the excavated soil and the ground improving agent.

[0003]

However, since all the above-mentioned stirring rods and the like rotate integrally with the excavation shaft, the excavated soil rotates integrally with the excavation shaft, which is a so-called co-rotation phenomenon. When a powdery ground improvement agent is used on the ground with a high water content, such as a lagoon, the excavated soil becomes a dumpling-like shape that encloses a stirring rod, etc. There was a drawback that it could not be done.

Further, since the ground improvement agent outflow hole is provided at a position higher than the excavation blade edge, even if the excavated soil is stirred by the stirring blade body, the ground improvement agent remains in the excavated soil at the bottom of the excavation hole. However, the unimproved ground was left at the bottom where most bearing capacity should be exerted, and the reliability of the improvement work was sometimes impaired.

[0005]

According to the present invention, the excavation shaft of the ground improvement device is formed as a double shaft of an outer shaft and an inner shaft which can be rotated in forward and reverse directions and rotate in mutually opposite directions. A cutting edge is continuously provided at the lower end of the
(2) Large agitating blade body) is fixed to both ends of the excavating blade edge and the large agitating blade body to form a substantially square V-shaped outer agitating blade body. An annular inner stirring blade is connected to the inner position, the outer stirring blade is fixed to either the outer shaft or the inner shaft, and the inner stirring blade is fixed to the shaft to which the outer stirring blade is not fixed. It is fixed so that the inner and outer stirring blades are configured to rotate in mutually opposite directions, and the outflow hole for the ground improvement agent is provided at the same level position as the excavating blade edge of the excavating shaft,
It is intended to provide a soil improvement device configured to rotate the excavation blade edge forward to excavate and move the excavated soil upward, and reversely rotate the excavation blade edge to move the soil improvement agent below the excavation blade edge. is there.

The central part of the cutting edge of the lower part of the outer stirring blade is fixedly attached to the lower end of the inner shaft, and the central part of the upper side of the outer stirring blade is rotatably supported on the outer periphery of the outer shaft. The upper and lower central portion is fixed to the outer shaft, and the outflow hole of the ground improvement agent is provided at the same level position as the excavating blade edge of the inner shaft, and the upper center portion of the outer stirring blade is fixed to the outer periphery of the outer shaft, The central part of the excavating blade under the outer stirring blade is rotatably supported on the lower end of the inner shaft, and the central part of the inner stirring vane is fixed to the inner shaft. It is also characterized in that an improving agent outflow hole is provided.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described in detail with reference to the drawings. In FIG.
Is composed of a movable base machine 1 and a ground improvement agent pump 2. The base machine 1 vertically supports an excavation shaft 4 by a leader 3, and is provided between the leader 3 and the excavation shaft 4. The hydraulic motor 5 rotates the excavation shaft 4 and the excavation cutting edge 6 that is continuously provided at the lower end of the coaxial shaft 4, and lowers the coaxial shaft 4 along the leader 3 so that the excavation hole H perpendicular to the ground G is formed. I am configuring.

The excavating shaft 4 is a double shaft, that is, a double reversing gear mechanism in which an inner shaft 8 is inserted inside a tubular outer shaft 7 and interposed between the upper ends of the coaxial shafts 7, 8 and the hydraulic motor 5. 9 are configured to rotate in mutually opposite directions, and the inner shaft 8
Extends further downward than the lower end of the outer shaft 7, and the lower end of the inner shaft 8 is provided with a digging edge 6 for excavation.

As shown in FIGS. 2 and 3, the excavating cutting edge 6 has a large number of cutting edge bits 6a arranged at the lower edge of the excavating cutting edge 6.
The main body 6b of the excavating blade edge 6 supporting the front is provided with a downward inclination angle θ, and when the inner shaft 8 is rotated in the forward direction, the excavated soil excavated by the blade edge bit 6a is sent upward, and in the opposite direction. Rotating it has the effect of pushing down the excavated soil.

Further, a lower end portion of a substantially U-shaped large stirring blade body 10a having a downward opening is fixedly provided at an upper end edge of the excavating blade tip 6, and is provided at a central portion of an upper side of the outer stirring blade body 10. Bearing part
The outer periphery of the outer shaft 7 is rotatably supported by 10b.

Inside the outer stirring blade body 10, a substantially semi-circular arc-shaped inner stirring blade body is provided, and the end portion of the inner stirring blade body is fixed to the outer periphery of the outer shaft 7.

Therefore, the inner stirring blade body rotates in the opposite direction to the outer stirring blade body 10 inside the substantially cylindrical rotating zone of the outer stirring blade body 10, so that the excavated soil does not form a dumpling shape and is finely divided. The excavated soil can be agitated.

A ground improving agent outflow hole 13 is disposed on the outer peripheral surface of the inner shaft 8 having the excavating blade tip 6 at the same level as the excavating blade tip 6, and the outflow hole 13 is formed in the inner shaft 8. The ground conditioner pump 2 is communicated with the ground conditioner flow passage 12 and the ground conditioner hose 16. The embodiment of the present invention is configured as described above, in the ground improvement work, first,
The excavation shaft 4 and the excavation blade edge 6 are rotated and lowered by the operation of the hydraulic motor 5 to form a circular columnar excavation hole H in the ground, but at this time, the earth in the excavation hole H is not discharged. The cutting edge 6 and the inner and outer stirring blade bodies 10 and 11 are buried in the excavated soil.

When the excavating cutting edge 6 reaches a predetermined depth, the descent of the excavation shaft 4 is stopped, and the ground improving agent from the ground improving agent pump 2 is injected from the ground improving agent outflow hole 13 to excavate the soil and the ground improving agent. While excavating the excavation shaft 4 while stirring and kneading and forming a ground improvement portion in the excavation hole H, in the present invention, when the excavated soil is stirred, the inner and outer shafts 8 and 7 are in the opposite direction to that in excavation. Rotate to.

As described above, when the excavating blade tip 6 integrated with the inner shaft 8 is rotated in the direction opposite to that at the time of excavation, the excavated soil existing above the excavating blade tip 6 is excavated due to the inclination angle θ of the excavating blade tip 6. It is pushed into the bottom of the excavation hole H below the cutting edge 6. At this time, since the ground improvement agent ejected from the outflow hole 13 arranged at the same level as the excavation blade tip 6 mixes with the excavated soil, the ground improvement agent is mixed with the bottommost part of the excavation hole H where the conventional ground improvement agent has not spread. The excavated soil can be fed and filled with the excavated soil containing the ground improvement agent without leaving the entire excavated hole H.

In particular, the outflow hole 13 for the ground improvement agent is provided in the excavating blade body 6.
Since it is arranged at the same level as above, the excavated soil containing a large amount of the ground improvement agent will be fed below the excavating cutting edge 6. When the excavating blade tip 6 integrated with the inner shaft 8 is rotated in the normal direction, the excavated soil containing a large amount of the soil improving agent is sent to the inner and outer stirring blade bodies 10 and 11 connected to the excavating blade tip 6 in the direction of the excavating blade and the excavating agent. It has the function of homogenizing the mixing with soil.

Further, since the inner and outer stirring blade bodies 10 and 11 are inverted with respect to each other, a shearing force acts on the excavated soil intervening between the blade bodies 10 and 11, and a complicated stirring action due to such inversion operation is performed. With this, the stirring and kneading action is strengthened to make the mixing of the excavated soil and the ground improvement agent more uniform, and the co-rotation phenomenon is prevented by the reversing operation, and reliable stirring and kneading can be performed. Is.

Furthermore, in the ground with a high water content, such as a lagoon,
It is desirable to use a powdery ground improvement agent, but in this case as well, by rotating the excavation cutting edge 6 in the direction opposite to that at the time of excavation,
The excavated soil mixed with the ground improvement agent can be sent to the bottom of the excavation hole H.

Further, when the powdery ground improving agent is used in such a ground, the shearing force of the excavated soil injected with the ground improving agent becomes larger than that of the ground on the inner peripheral wall of the excavation hole H, and the conventional stirring is performed. In the wing body, the wing body was wrapped in a dumpling shape and sufficient stirring and kneading could not be performed.
Since they are mutually reversed, the above-mentioned dumpling is prevented and sufficient kneading with stirring is carried out.

Also in this case, the excavated soil mixed with the ground improvement agent can be fed to the bottom of the excavation hole H by rotating the excavation blade edge 6 in the direction opposite to that at the time of excavation.

The above-mentioned powdery ground improving agent is made to flow in a pipe line in the same manner as a fluid by suspending the powdery ground improving agent in an air flow by a so-called air powder transport method, and then flowing out from an outflow hole. Can be injected with air.

The stirring and kneading of the excavated soil and the ground improvement agent include the mechanical stirring and kneading described above and the stirring and kneading by injecting the ground improvement agent at an ultrahigh pressure (about 200 kg / cm ² ) from the ground improvement agent outflow hole. The rotation speed of the excavating shaft differs from 50 RPM for mechanical agitation and 20 RPM for jet agitation, respectively. By reversing the blade body 10 at low speed and the small stirring blade body 11 at high speed, both stirring and kneading methods can be carried out by one device, and mechanical stirring and jet stirring are used at the same time. It can be constructed by the construction method.

Also in this case, the excavated soil mixed with the ground improvement agent can be sent to the bottom of the excavation hole H by rotating the excavation blade edge 6 in the direction opposite to that at the time of excavation.

In FIG. 5, the central portion of the upper side of the outer stirring blade body 10 is fixed to the outer periphery of the outer shaft 7, and the central portion of the excavating blade 6 at the lower portion of the outer stirring blade body 10 is freely rotatable to the lower end of the inner shaft 8. And the inner end portion of the inner stirring blade body 11 is fixed to the inner shaft 8, and the outflow hole of the ground improvement agent is provided at the same level position as the excavating blade edge 6 of the inner shaft 8.
Another embodiment is shown in which 13 is provided and the opening 20 is provided at the same height position as the outflow hole 13 in the central portion of the excavating blade tip 6, and it has the same effect as the above.

As described above, since the ground improvement agent can be spread to the bottom of the excavation hole H that bears the most support force, the improved support capacity of the ground is improved and the reliability of the ground improvement work is improved. It is possible to improve the property.

In FIG. 4, the inner and outer shafts 7 and 8, the outer stirring blade body 10, the excavating cutting edge 6 and the ground improvement agent outflow hole 13 are configured in the same manner as in the above embodiment, and the inner stirring blade body 11 is formed in a square shape. Another embodiment is shown.

In FIG. 5, the upper and lower parts of the inner stirring blade body 11 are the inner shaft 8
The upper part of the outer stirring blade body 10 is fixed to the outer shaft 7, and the lower part is fixed to the tip part of the excavating blade body 6 which is loosely fitted to the inner shaft 8 via the bearing part 6a. A laterally elongated opening 6b is formed in the bottom of the inner shaft 8 and a ground improvement agent outflow hole 13 is provided at the lower end of the inner shaft 8.
Another embodiment is shown in which the is exposed to the outside.

[0028]

According to the present invention, the ground improving agent outflow hole is provided at the same level as the drilling cutting edge continuously provided at the lower end of the drilling shaft of the ground improving apparatus. The ground improvement agent can be sent to the bottom of the excavation hole, which bears the most load, and the bearing capacity of the improved ground can be increased and the reliability of the improvement work can be improved.

Further, the excavating shaft for stirring and kneading the excavated soil and the ground improvement agent is formed as a counter-rotating shaft, the excavating blade tip integrated with the outer stirring blade is fixed to the inner shaft, and the inner stirring is fixed to the outer shaft. By connecting the blades to rotate the inner and outer stirring blades in mutually opposite directions, and by arranging the outflow holes for the ground improvement agent on the outer peripheral surface of the inner shaft at the same level as the excavating blade edge, By rotating in the opposite direction to the direction of excavation, the excavated soil containing the soil improvement agent is sent to the bottom of the excavation hole, which bears the most supporting force, and the stirring and mixing of the excavation soil and the soil improvement agent are ensured and improved. The bearing capacity of the ground can be increased and the reliability of the improvement work can be improved.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing the overall configuration of a ground improvement device according to the present invention.

FIG. 2 is a side view showing an outflow hole of a ground improvement agent and a stirring blade structure.

FIG. 3 is a side view showing an outflow hole and a stirring blade structure of a ground improvement agent as another embodiment.

FIG. 4 is an explanatory view showing an outflow hole of a ground improvement agent and a stirring blade structure as another example.

FIG. 5 is an explanatory view showing an outflow hole and a stirring blade structure of a soil improvement agent as another embodiment.

[Explanation of symbols]

 (A) Ground improvement device (4) Excavation shaft (6) Excavation edge (6) (7) Outer shaft (8) Inner (10) Outer stirring blade (10a) Large stirring blade (11) Inner stirring blade ( 13) Outflow hole

Claims (3)

[Claims] 1. An outer shaft (7) and an inner shaft capable of rotating the excavating shaft (4) of the ground improvement device (A) in the forward and reverse directions and in mutually opposite directions.
It is formed as a double shaft of (8), and a drilling blade tip (6) is connected to the lower end of the drilling spindle (4), and a downward opening U-shaped large stirring is provided at the outer end of the drilling blade tip (6). By fixing both lower ends of the blade body (10a), the excavating blade edge (6) and the large stirring blade body (10a) form an integral substantially R-shaped outer stirring blade body (10). An annular inner stirring blade body (11) is connected to the inner position of the outer stirring blade body (10) in (4), and the outer stirring blade body (10) is attached to either the outer shaft (7) or the inner shaft. The inner stirring blade body (11) is fixed to the shaft where the outer stirring blade body (10) is not fixed, and the inner stirring blade body (10) is fixed.
(11) are configured to rotate in mutually opposite directions, and a ground improvement agent outflow hole (13) is provided at the same level position as the excavating blade edge (6) of the excavating shaft (4) to provide the excavating blade edge (6). The ground improvement device is configured to rotate normally to perform excavation and upward movement of the excavated soil, and reversely rotate the excavation blade edge (6) to move the soil improvement agent below the excavation blade edge (6). 2. An excavating cutting edge at a lower portion of the outer stirring blade body (10)
(6) Secure the center part to the lower end of the inner shaft (8), and
(0) Center the upper side of the outer shaft (7) rotatably around the outer shaft,
Secure the upper and lower central parts of the inner stirring blade (11) to the outer shaft, and
The ground improvement device according to claim 1, wherein a ground improvement agent outflow hole (13) is provided at the same level as the excavating blade edge (6) of (8). 3. The central portion of the upper side of the outer stirring blade body (10) is fixed to the outer periphery of the outer shaft (7), and the central portion of the drilling blade tip (6) below the outer stirring blade body (10) is fixed to the inner shaft (8). ) Is rotatably supported at the lower end, and the central part of the inner stirring blade body (11) is fixed to the inner shaft (8).
2. The ground improvement device according to claim 1, wherein an outflow hole (13) for the ground improvement agent is provided at the same level position as the excavating blade edge (6) of the inner shaft (8).