JP3251724B2 - Agitation blade structure of ground improvement equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art Conventionally, as one method for improving soft ground, a vertical hole is drilled in the ground with a base machine or the like, and excavated soil and a hardening agent are stirred and kneaded in the vertical hole, and the excavated soil is hardened with a hardening agent. In order to stir and knead the excavated soil and the hardening agent, a stir bar or the like protruding from the excavation shaft is used.

[0003]

However, since all of the stirring rods and the like described above rotate integrally with the excavation shaft, the excavated soil rotates integrally with the excavation shaft. In particular, when a powdery hardening agent is used on the ground with a high water content, such as a lagoon, the excavated soil becomes a dumpling shape that wraps around the stirring rod, etc., and the stirring and kneading can not be performed at all. There was a disadvantage that there was no.

Therefore, the excavating shaft is constituted by a double shaft consisting of an inner shaft and an outer shaft which rotate in opposite directions, and a stirring blade is connected to each shaft so that the stirring blades are moved in the opposite direction in the excavated soil. The applicant of the present invention has filed an application to prevent the corotation phenomenon and the excavated soil from forming a dumpling shape by rotating the shaft (see Japanese Patent Application No. 60-6477).

However, even in the above invention, in the improvement of the ground of the peat layer, the peat layer contains a lot of fibrous materials formed by the corrosion of plants and the like. No matter how much stirring, many lumps of unstirred soil remain due to these pills, and the stirring and kneading of the ground improver and the excavated soil are not sufficiently performed.
There is a problem in that the bearing capacity of the improved ground is reduced and the bearing capacity is varied, thereby impairing the reliability of the ground improvement work.

[0006]

According to the present invention, the excavation shaft of the soil improvement device is formed as a double shaft of an outer shaft and an inner shaft rotating in opposite directions, and an annular stirring blade is provided at a lower end of the excavation shaft. The agitating blades are configured to rotate in opposite directions to each other, and a number of agitating rods are protruded from each agitating blade at appropriate intervals, and adjacent agitating blades are arranged. In the agitating blade structure of the ground improvement device, the agitating rod protruding from one of the agitating blades intervenes during the interval between the agitating rods protruding from the other agitating blade. The lower end of the blade is fixed to the lower end of the inner shaft, and the upper end of the large stirring blade is rotatably fitted to the outer shaft. Is fixed to the outer shaft, and the lower end of the middle stirring blade is rotatably fitted to the inner shaft. The lower end of the body is fixed to the lower end of the inner shaft, and the upper end is rotatably fitted to the lower end of the outer shaft to form a large / medium / small agitating blade that is alternately inverted. A number of stirring rods are protruded on the inner surface at appropriate intervals, and stir bars that can intervene during the interval are protruded on the outer surface of the middle stirring blade, and are appropriately spaced on the inner surface of the middle stirring blade. , A large number of stirring rods are protruded, and a stirring rod that can intervene during the above-mentioned interval is protruded on the outer surface of the small stirring blade body, and a large number of them are held on the inner surface of the small stirring blade body at appropriate intervals. And a stirrer structure of a ground improvement device characterized in that a stirrer rod protruding from the outer shaft (7) is provided on the outer peripheral surface of the outer shaft (7). .

[0007]

An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows the overall configuration of a ground improvement apparatus A, which comprises a movable base machine 1 and a hardener pump 2, and the base machine 1 vertically supports an excavation shaft 4 by a leader 3. By lowering the coaxial 4 along the leader 3 while rotating the excavating shaft 4 and the cutting edge 6 connected to the lower end of the coaxial 4 by the hydraulic motor 5 interposed between the leader 3 and the excavating shaft 4, It is configured such that a drill hole H perpendicular to the ground G is formed.

The excavating shaft 4 has a double shaft, that is, a double reversing gear mechanism 9 interposed between the upper ends of the coaxial shafts 7 and 8 and the hydraulic motor 5 with an inner shaft 8 inserted into a tubular outer shaft 7. , The inner shaft 8 extends further downward than the lower end of the outer shaft 7.
An excavation blade tip 6 for excavation is continuously provided at a lower end of the excavator.

A stirring blade B composed of large, medium and small stirring blade bodies 10, 11, and 12 rotating in opposite directions is connected to a position above the cutting edge 6 of the cutting shaft 4.

Each of the stirring blades 10, 11, 12 is formed in a substantially semi-circular arc shape, and inside the rotation zone of the large stirring blade 10, the middle stirring blade 11 is rotated by the rotation zone of the medium stirring blade 11. Each of the small stirring blades 12 rotates in the opposite direction to the adjacent stirring blade.

That is, the lower end of the outermost large stirring blade body 10 is fixed to the lower end of the inner shaft 8 above the excavation cutting edge 6.
The upper end of the large stirring blade 10 is rotatably fitted to the outer periphery of the outer shaft 7 via a bearing 10b via a bearing 10b, and the upper end of the middle stirring blade 11 is fixed to the outer shaft 7a. The lower end is rotatably fitted to the inner shaft 8 via a bearing 11b, and the lower end of the small stirring blade body 12 is fixed to the lower end of the inner shaft 12; the upper end 12b is connected to the lower end of the outer shaft. The outer fitting 12c is rotatably mounted on the outer periphery of the housing 12 via a bearing 12b.

The inner surface of the large stirring wing body 10 is appropriately spaced.
While holding d1, a number of stirring rods 10d protrude, and the medium stirring blade 11
A stirring rod 11d that can intervene during the interval d1 protrudes from the outer surface of.

Further, an appropriate distance d2 is provided on the inner surface of the
, A large number of stirring rods 11e are protrudingly provided, and a stirring rod 12d which can intervene in the above-mentioned interval d2 is provided on the outer surface of the small stirring blade body 12.

Further, an appropriate distance d3 is provided on the inner surface of the small stirring blade body 12.
, A large number of stirring rods 12e are protruded, and a stirring rod 7a protruding from the outer peripheral surface of the outer shaft during the interval is protruded.

In FIG. 1, reference numeral 7b denotes a bearing provided between the inner and outer shafts 8,7.

With the above configuration, the inner and outer shafts 8, 7
Are rotated in opposite directions, the large stirring blade body 10 and the small stirring blade body 12 are integrated with the inner shaft 8, and the middle stirring blade body 11 is rotated in the opposite direction to the inner shaft 8. Since the stirring blades adjacent to each other rotate in the opposite directions to each other, the stirring rod 10d protruding from the inner surface of the large stirring blade 10 and the outer surface of the medium stirring blade 11 The protruding stirring rods 11d pass each other at a narrow interval.

Similarly to the above, a stirring rod 11d protruding from the inner surface of the medium stirring blade 11 and a stirring rod 12d protruding from the outer surface of the small stirring blade 12 and an inner surface of the small stirring blade 12 are provided. The protruding stirring rod 12e and the protruding 7a protruding from the outer peripheral surface of the outer shaft 7 are different from each other at a narrow interval.

At the lower end of the inner shaft 8, a hardening agent nozzle 13 for injecting a hardening agent is disposed in a rotating range of the front small stirring blade body 12 with the spraying direction being horizontal. Is connected to the hardener pump 2 via a passage 14 provided in the inner shaft 8 and a swivel joint 15 and a hose 16 connected to the upper end of the inner shaft 8.

The embodiment of the present invention is constructed as described above. In the ground improvement work, first, the hydraulic motor 5
By rotating the excavation shaft 4 and the excavation tip 6 by rotating the excavation hole, a circular column-shaped excavation hole H is formed in the ground. At this time, the excavation in the excavation hole H is not performed. 6
The large and small stirring blades 10, 11 are buried in the excavated soil.

When the cutting edge 6 reaches a predetermined depth, the lowering of the excavating shaft 4 is stopped, the hardening agent from the hardening agent pump 2 is injected from the hardening agent nozzle 13, and the excavated soil and the hardening agent are stirred and kneaded. The excavation shaft 4 is raised while forming a ground improvement portion in the excavation hole H.

Since the large, medium and small stirring blades 10, 11 and 12 are reversed, shearing force acts on the excavated soil interposed between the stirring blades 10, 11 and 12, and the soil mass is subdivided. To prevent the co-rotation of the excavated soil and the formation of dumplings.
Due to the reversal of 0,11,12, a complicated stirring action works to make the mixing of the excavated soil and the hardener more uniform and reliable.

In particular, when a large number of stirring rods 10d, 11d, 11e, 12d, 12e, 7a protruding from each of the stirring blades 10, 11, 12 pass each other at a narrow interval, the peat layer ground improvement work is performed. Since the fibrous material contained in the layer is not cut and pills are not generated, there is no unstirred soil mass or soil mass with no hardening agent mixed, and a ground improvement part where excavated soil and hardening agent are uniformly mixed is formed can do.

It is desirable to use a powdery hardening agent in a ground having a high water content such as a peat layer. However, when a powdery hardening agent is used in such a ground, the hardening of the inner peripheral wall of the excavation hole H is more difficult than in the ground. The excavated soil that has been sprayed with the agent has a higher shearing force, and the fibrous material makes it easier for the excavated soil to be bunched.With conventional stirring blades, the wings are wrapped in a dumpling shape and sufficient stirring and kneading is performed. Although it could not be performed, with the stirring blade of the present invention, large, medium and small stirring blades 10, 11, 12
Are reversed to each other, and the large, medium and small stirring blades 10, 11, 12
Are provided with stir bars, and these stir bars pass each other at a narrow interval, so that the fibrous material is shredded, the above-mentioned conglomeration is prevented, and sufficient stirring and kneading are performed. .

The powdery hardener is obtained by suspending the powdery hardener in an air stream by a so-called air powder transport method, flowing the same in a pipeline as substantially a fluid, and injecting the same from the injection nozzle with air. Can be.

FIG. 3 shows that the large, medium and small stirring blades 20, 21, 22 are square, and the large, medium and small stirring blades 20, 21, 22 and the outer shaft 7 have stirring rods 20a, 21a, 21b, 22a. , 22b and 23a.

FIG. 4 shows a multiple stirring blade B composed of two large and small stirring blades 30, 31. The large and small stirring blades 30, 31 and the outer shaft 7 have a stirring rod 30a. , 31a, 31b, 32a.

[0028]

According to the present invention, the excavation shaft of the soil improvement device is formed as a double shaft of an outer shaft and an inner shaft rotating in opposite directions, and an annular stirring blade body is provided at the lower end of the excavation shaft. A plurality of adjacent stirring blades are arranged so as to rotate in opposite directions to each other, and a number of stirring rods are protruded from each stirring blade at appropriate intervals. In the meantime, the excavated soil is turned in the opposite direction to each other by the configuration in which the stirring rod projecting from one stirring blade is interposed in the above-mentioned interval between the stirring rods projecting from the other stirring blade. It is finely divided by a stirring rod, and at the same time, the fibrous material in the peat layer is also plowed and no pills are generated.Therefore, there is no problem that unstirred soil mass remains, and excavated soil and soil improvement agent Of the improved ground in the peat layer, To prevent variation has the effect of improving the reliability of the ground improvement work.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a configuration of a ground improvement device having a stirring blade structure according to the present invention.

FIG. 2 is a side view of the stirring blade structure.

FIG. 3 is an explanatory view of a stirring blade structure as another embodiment.

FIG. 4 is an explanatory view of a stirring blade structure as another embodiment.

[Explanation of symbols]

 (4): Drilling axis (7): Outer axis (8): Inside (10): Large stirring blade (11): Small stirring blade

Continuation of front page (56) References JP-A-3-199521 (JP, A) JP-A-2-54016 (JP, A) JP-A-61-10620 (JP, A) JP-A-61-87021 (JP) , A) JP-A-61-165416 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) E02D 3/12 102

Claims (1)

(57) [Claims] The excavation shaft of the soil improvement device is formed as a double shaft of an outer shaft and an inner shaft rotating in opposite directions to each other, and a plurality of annular stirring blades are continuously provided at a lower end of the excavation shaft. , Each of the adjacent stirring blades is configured to rotate in the opposite direction to each other, and a number of stirring rods are protruded from each of the stirring blades at appropriate intervals, and one stirring is performed between the adjacent stirring blades. In the stirring blade structure of the ground improvement device configured so that the stirring rod protruding from the wing body intervenes during the interval between the stirring rods protruding from the other stirring wing body, the lower end of the large stirring wing body (10) is Secured to lower end of inner shaft (8) (10a)
And the upper end of the large stirring blade (10) is rotatable around the outer shaft (7).
Externally fitted (10c) and inside the rotating circle of the large stirring blade (10)
And fix the upper end of the middle stirring blade (11) to the outer shaft (7) (11a).
And the lower end of the stirring blade (11) is rotatable about the inner shaft (8).
Externally fitted (11b) and inside the rotating circle of the middle stirring blade body (11)
The lower end of the small stirring blade (12) is fixed to the lower end of the inner shaft (8) (12
a) Then, the upper end is rotatably fitted to the lower end of the outer shaft (7) (12).
b) The large, medium and small stirring blades (10) (11) (12)
And a suitable space (d1) on the inner surface of the large stirring blade (10).
And a number of stirring rods (10d) protrude from the middle stirring blade (11).
Attach a stirrer rod (11d) that can intervene into the outer side during the interval (d1).
And maintain an appropriate spacing (d2) on the inner surface of the middle stirring blade body (11).
A large number of stirring rods (12e) protruding from the outside of the small stirring blade (12).
A stir bar (12d) that can intervene during the above interval (d2)
And maintaining an appropriate interval (d3) on the inner surface of the small stirring blade body (12).
A large number of stirring rods (12e) are protruded, and the outer shaft (7)
A stirring blade structure for a ground improvement device, wherein a stirring rod (7a) capable of intervening is protruded during the interval (d3) .