JPS6286220A - Stirrer for mixing treatment of deep layer - Google Patents

Abstract

PURPOSE:To sufficiently mix excavated soil with a chemical grout with stirring under a condition where leakage is prevented by relatively turning a resistance blade and an excavating blade. CONSTITUTION:A rotary current 1 is provided to the lower end of a rotary shaft 2 having a chemical grout-passing pipeline 4 inside. Excavating blades 21 and resistance blades 22 are provided through a speed change gear 20 around the shaft 2 in such a way that the blades 21 and 22 are turned with relatively different speeds around the shaft 2 by means of the gear 20. When the shaft 2 for turning a rotary cutter 1 is turned, since the blades 21 and 22 are turned with different speeds to different directions, cohesive soil is cut between the blades 21 and 22 and an improving agent is well dispersed into the cohesive soil.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a stirring device used in a deep mixing method for improving soft ground and the like.

(Prior art) The deep mixing method is a method for strongly improving soft ground, for example, and general examples of this are shown in Figures 6 to 11.
This will be explained based on the diagram. First, as shown in FIG. 6, a stirring device equipped with a rotary shaft 2 having a rotary cutter l attached to the lower end is prepared.

A stirring blade 3 is fixed around the rotary shaft 2 at a position above the rotary cutter l, and a conduit 4 is provided inside the rotary shaft 2 for conducting a chemical solution such as a hardening agent. ing. The upper end of this rotating shaft 2 is connected to a rotational drive device (
(not shown) and a chemical solution supply device (not shown), which are attached to a turret (not shown) or the like on the ground. The stirring device configured in this manner is located above the ground 5 to be improved. Next, the rotary shaft 2 is pushed down into the ground 5 as shown in FIG. 7 while rotating the rotary cutter 1, and the excavation by the rotary cutter 1 is carried out to a predetermined depth in the ground 5 as shown in FIG. It is done.

Next, as shown in FIG. 9, the rotary shafts 2 are sequentially pulled out, but at this time, the rotary cutter l excavates the ground 5 and
This excavated earth and sand is mixed with a curing agent and the like that are ejected from the opening at the lower end of the chemical fluid conduit 4. In order to mix the curing agent and excavated soil more uniformly, the stirring blade 3
is rotated together with the rotating shaft 2. And Figure 1θ-
When the rotary cutter 1 reaches almost the upper end of the ground 5, the ejection of the chemical solution is stopped. Finally, as shown in FIG. 11, the rotating shaft 2 is completely pulled out from the ground 5. Thereafter, at a predetermined location on the ground 5, a ground improved by the hardened chemical solution (indicated by hatching) is formed.

Various types of stirring blades are used as the stirring blades 3, as shown in FIGS. 12 to 14, in order to improve the mixing effect of the excavated earth and sand and the chemical solution. The stirring blade 3 shown in FIGS. 12 and 13 is of the type proposed in Japanese Utility Model Publication No. 58-17787, and includes a blade 6 fixed to the rotating shaft 2 in an oval shape, and a center of the blade 6. It consists of a linear blade 7 fixed to the rotary shaft 2 so as to intersect with the rotary shaft 2 at a position.

In addition, the stirring blade 3 in Fig. 14 is a Japanese Utility Model Publication No. 56-40908
It is of the type shown in the publication, and the rotating shaft 2
It is made up of a plurality of arms 8 fixedly fixed in a state perpendicular to the ground, and a large number of stirring plates 9 fixedly attached to each arm 8.

(Problems to be Solved by the Invention) The conventional stirring blades 3 described above are all fixed to the rotating shaft 2, so in the case of cohesive soil with high adhesive strength, the entire soil rotates together with the stirring blades 3. chemical solution (improving material for cement, etc.)
The problem is that it does not disperse into the soil.

For this reason, it has been proposed to fix co-rotation prevention blades 13 around the rotating shaft 2 below the stirring blade 3, as shown in FIG. Although this idea is good, in this case, the blade I3, which is longer than the excavation diameter, must be penetrated into the ground and pulled out, resulting in a problem of increased resistance. In addition, it is questionable whether co-rotation is completely prevented and the effect is improved in soft ground where there is no resistance (generally, ground that requires ground improvement is soft). In addition, to prevent co-rotation, multiple rotating shafts 2
(Japanese Patent Publication No. 58-26451,
(See Japanese Utility Model Publication No. 54-33682, etc.) has also been proposed, but the structure is complicated.

The present invention was made in order to solve such conventional problems, and its purpose is to provide a simple structure with blades that can cut through the clay soil in order to disperse improvement materials well in the clay soil. The object of the present invention is to provide a stirring device with a structure.

(Means for Solving the Problems) The present invention provides a rotating shaft having a rotary cutter attached to the lower end and a chemical fluid passageway inside, and a transmission device arranged around the rotating shaft at a position near the rotary cutter. a cutting gap attached through the cutting gap, and a resistance blade attached around the rotating shaft via the transmission at a position above the cutting gap, and the cutting gap and the resistance blade are connected to the cutting gap by the transmission. This is a stirring device for deep mixing processing that rotates at relatively different speeds around a rotating shaft.

(Function) When the rotary shaft is rotated in order to rotate the rotary cutter, this rotational force is automatically transmitted to the cutting gap and the resistance blade through the transmission device, and these rotate at different speeds. In other words, the rotary cutter rotates at different speeds or in different directions to prevent the earth and sand excavated by the rotary cutter from co-rotating with the rotary cutter, and to prevent the cohesive soil from rotating between the cutting dog and the resistance blade. Cut to ensure good dispersion of the modifier into the viscous top.

(Example) The present invention will be described below based on the example shown in FIGS. 1 to 5. Note that the same reference numerals will be used to describe the same parts as in the prior art.

FIG. 1 and FIG. 2 show an embodiment of the present invention, and this stirring device has a rotary shaft 2 having a rotary ground cutter 1 attached to its lower end and a chemical fluid conduit 4 inside, a cutting gap 21 attached via a transmission 20 around the rotating shaft 2 at a position near the cutter 1;
A resistance blade 22 is attached to the circumference of the rotating shaft 2 via the transmission 20 at a position above the cutting gap 21.
It is equipped with

The cutting gap 21 is made of a single plate-shaped member that intersects with the rotating shaft 2, and is inclined with respect to the horizontal plane like a propeller.

Further, the resistance blade 22 is composed of two plate-shaped members that intersect in a cross shape with respect to the rotation axis 2, and these plate members are perpendicular to the horizontal plane. Therefore, the resistance 822 and the cutting gap 21 receive different resistances from the excavated earth and sand.

On the other hand, in this embodiment, the transmission 20 includes a spur gear 23 fixed around the rotating shaft 2, and a spur gear 23 fixed around the rotating shaft 2.
A plurality of planetary gear-like binion gears 24 meshed around the periphery of
and an internal gear 25 meshed with the outer periphery of these pinion gears 24. The internal gear 25 is loosely fitted around the rotating shaft 2, and the cutting gap 21 is attached to the outside of the internal gear 25. Further, the central boss 22a of the resistance blade 22 is loosely fitted around the rotating shaft 2, and the central shaft 26 of each pinion gear 24 is fixed to the lower surface of the central boss 22a.

Therefore, when the rotating shaft 2 rotates clockwise as shown by the arrow, for example, the ta resistance blades 22 perpendicular to the horizontal plane receive the greatest resistance from the earth and sand, causing the pinion gear 24 to rotate, and as a result, the internal gear 25 Rotate counterclockwise. Therefore, when the resistance blade 22 is almost stationary or rotates slightly clockwise, the cutting R21 rotates counterclockwise, and the cutting 121 and the resistance blade 22 rotate at different speeds in opposite directions. It will rotate.

As is clear from the structure of the above embodiment, the rotary cutter 1
By simply rotating the rotary shaft 2 when excavating the ground 5, the cutting gap 21 and the resistance blade 22 automatically rotate at relatively different speeds, so that shearing of the cohesive soil is performed between them. The chemical solution and excavated soil are sufficiently stirred and mixed. Also, between the rotary cutter 1 and the cutting gap 21 or the resistance blade 2
There is also a possibility that shearing of earth and sand may occur between the two.

Therefore, the problem of co-rotation of earth and sand is solved.

3 to 5 show other embodiments of the present invention, in which the transmission device 20 is arranged around the ends of a plurality of support shafts 27 that integrally project from the rotation shaft 2 in the lateral direction. a plurality of small bevel gears 28 rotatably pivotally connected to the small bevel gears 28;
a first bevel gear 29 that meshes with each of the small bevel gears 28 on the lower side thereof and is loosely fitted around the rotating shaft 2;
a second gear meshing with each of the small bevel gears on the upper side of each of the small bevel gears 28 and loosely fitted around the rotating shaft 2;
It has a bevel gear 30. The cutting gap 21 is fixed around the extended portion of the first bevel gear 29 , and the resistor 822 is fixed around the extended portion of the second bevel gear 30 .

In this embodiment, the transmission 20 operates on the same principle as a differential gear in an automobile, and the rotation of the rotating shaft 2 is transmitted to the first and second bevel gears 29 via a small bevel gear 28.
．． 30, but the deceleration of the resistance blades 22 is added as an increase in speed during the cutting interval 21.

Therefore, the cutting gap 21 and the resistance blades 22 can rotate at mutually different speeds, and can shear the excavated earth and sand. Therefore, the same effect as that shown in FIG. 1 is achieved. Note that other configurations are also possible for the transmission 2o.

Furthermore, in each of the above embodiments, the cutting gap 21 is inclined like a propeller in order to make the resistance received by the cutting gap 21 and the resistance blade 22 from the cutting earth and sand different, but instead of this, the area of the cutting gap 21 is It may be made smaller, or even if the cutting gap 21 and the resistance H22 are subject to the same resistance, the transmission device 2° may be structured so that they are forcibly rotated at different speeds.

(Effects of the Invention) As described above, according to the present invention, a transmission is provided around the rotating shaft for rotating the rotary cutter, resistance blades and cutting gaps are attached to the upper and lower parts of the transmission, and the rotating shaft is When rotating, the resistance blade and the cutting blade are automatically rotated at relatively different speeds (different speeds or different directions), so the structure is simple and does not require a separate power device. By rotating the resistance blade and the cutting blade relative to each other by t, the excavated earth and sand are sheared by the rotary cutter, and the excavated earth and the chemical solution can be sufficiently stirred and mixed while preventing co-rotation.

In addition, the improvement effect of the deep mixing treatment method for cohesive soil depends entirely on the stirring state, but this device enables efficient stirring and mixing, improving reliability and saving improvement materials. Efficiency will be improved.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a stirring device according to an embodiment of the present invention;
2 is a vertical cross-sectional view of the main part of FIG. 1, FIG. 3 is a perspective view of a stirring device according to another embodiment of the present invention, FIG. 4 is a longitudinal cross-sectional view of the main part of FIG. 3, and FIG. is a perspective view of the main part of Figure 4, Figures 6 to 11 are process explanatory diagrams of a general deep mixing method, and Figure 1
2 to 14 are perspective views of conventional stirring devices, respectively. DESCRIPTION OF SYMBOLS 1...Rotating cutter, 2...Rotating shaft, 4...Medical solution conduit, 5...Ground, 20...Transmission device, 21.
...Cutting blade, 22...Resistance blade, 22a...Central boss, 23...Spur gear, 24...Binion gear, 25...
... Internal gear, 26 ... Center shaft, 27 ... Support shaft, 2
Day...Small bevel gear, 29...First bevel gear, 30...
2nd bevel gear. Figure 12 Figure 13 Figure 14

Claims (1)

[Claims] A rotary shaft having a rotary cutter attached to the lower end and a chemical fluid passageway inside, a cutting blade attached via a transmission around the rotary shaft at a position near the rotary cutter, and an upper part of the cutting blade. and a resistance blade attached via the transmission around the rotation axis at a position, the cutting blade and the resistance blade being rotated at relatively different speeds around the rotation axis by the transmission. A stirring device for deep mixing processing, characterized in that: