JPH10252054A - Ground improving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a joint rotation phenomenon by rotating a main stirring wing fitted perpendicularly to a rod body in the plane perpendicular to the rod body axis, and rotating an auger-shaped auxiliary stirring wing assembled in the main stirring wing and provided around a shaft along the longitudinal direction of the main stirring wing. SOLUTION: A nearly rectangular notch section is bored along the longitudinal direction in a main stirring wing 12, and an auger-shaped auxiliary stirring wing 20 is installed in it. When the auxiliary stirring wing 20 is rotated with its auxiliary stirring shaft used as the axis, a spiral band material 24 is rotated to cut the peripheral ground in the direction other than the horizontal direction, the sticking of sediment to the main stirring wing 12 is prevented, and the stirring effect is improved. When this spiral band material 24 is rotated in the prescribed direction, the sediment kept in contact with the face of the band material 24 is shifted to the outside of the radial direction of a rod body 11, and the sticking of sediment to the periphery of the rod body 11 can be prevented. A joint rotation phenomenon can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ground improvement apparatus for mechanically stirring a soft ground to improve the ground, and more particularly to a ground improvement apparatus having a stirring mechanism for preventing the ground from rotating when the ground is improved.

[0002]

2. Description of the Related Art Heretofore, a method of forming a ground improvement body by injecting a solidifying agent made of cement, lime, or the like at a high pressure into various soil layers has been performed. Specifically, a rod body having a solidifying agent transfer pipe serving as a flow path for the solidifying agent or the like is inserted into a drilled hole having a predetermined depth, and a stirring blade provided on the rod body is rotated and vertically moved. In addition, a high-pressure injection of the solidifying agent is performed from an injection nozzle provided near the lower end of the solidifying agent transfer pipe to form a columnar ground improvement body.

[0003] As an example of the stirring mechanism of the conventional ground improvement apparatus, a mechanism for forcibly stirring the soil by a blade for stopping the rotation of the soil and a rotating stirring blade, or a plurality of stirring blades in opposite directions are used. There was a mechanism by relative agitation to rotate to. In this case, the stirring blade was rotated only in a plane perpendicular to the axis of the stirring rod.

[0004]

In a conventional ground improvement apparatus having a stirring mechanism, the stirring wing rotates only in a plane perpendicular to the axis of the stirring rod. Often occurred. As a result, sufficient stirring becomes difficult, and the strength of the formed ground improvement body varies. In addition, there is a problem that the stirring time becomes long to perform sufficient stirring.

[0005] Here, the circling phenomenon refers to a phenomenon in which the soil adheres to the stirring blade, and the stirring blade and the soil rotate together, particularly in a viscous ground.

The present invention has been made in view of the above-mentioned problems, and when the ground is improved by a ground improvement apparatus using mechanical stirring, it is possible to effectively prevent the turning phenomenon, improve the stirring efficiency between the ground and the solidifying agent, and improve the stirring time. The aim is to shorten the. It is also intended to improve the quality of the improved ground.

[0007]

The above-mentioned object is achieved by the present invention described below.

[0008] A first aspect of the soil improvement device according to the present invention is a rod body, which is built into the rod body to form a ground improvement body by injecting and stirring a solidifying agent into soft ground by mechanical stirring. A solidifying agent transfer pipe for transferring a solidifying agent, an injection port of the solidifying agent opened at an outer periphery near the tip of the rod body, and a rod extending perpendicularly to the rod body axis above the injection port; In a ground improvement device including a main stirring blade that rotates with rotation of a body, a notch formed in a substantially rectangular shape from a base to a tip of the main stirring blade, and a longitudinal direction of the notch And an auxiliary stirring shaft rotatably supported at both ends of the auxiliary stirring shaft and an auxiliary stirring blade made of a band helically wound around the auxiliary stirring shaft; and Turn the auxiliary stirring blade as an axis And a rotary driving mechanism for.

In a second aspect of the soil improvement apparatus according to the present invention, a rod body and a rod body are built in the rod body to form a ground improvement body by injecting and stirring a solidifying agent by mechanical stirring into soft ground. A solidifying agent transfer pipe for transferring the solidifying agent, an injection port of the solidifying agent opened on the outer periphery near the tip of the rod body, and the rod body provided above the injection port and perpendicular to the rod body axis; A ground improvement device including a main stirring blade that rotates with the rotation of the main stirring blade, a cutout portion that is formed in a substantially rectangular shape from a base portion to a tip portion of the main stirring blade, and a strip material that is spirally wound. An auxiliary stirrer blade that is formed in the longitudinal direction of the notch portion and rotatably supported at both ends thereof, and a rotation that rotates the auxiliary stirrer blade with the spiral shaft of the spiral shape as the axis of the auxiliary stirrer blade. A driving mechanism.

In a third aspect of the ground improvement apparatus according to the present invention, the rotary drive mechanism has an impeller provided in the solidifying agent transfer pipe, and the impeller rotates by receiving a transfer pressure of the solidifying agent. And a shaft connected to a shaft of the auxiliary stirring blade and transmitting rotation of the blade to the auxiliary stirring blade.

In a fourth aspect of the ground improvement apparatus according to the present invention, the rotary drive mechanism has a transfer pipe for transferring compressed air and an impeller provided in the transfer pipe, and the impeller is provided with the compressed air. And a shaft connected to the shaft of the auxiliary stirring blade and transmitting the rotation of the blade to the auxiliary stirring blade.

In a fifth aspect of the ground improvement apparatus according to the present invention, the rotary drive mechanism has a motor.

[0013]

As described above, according to the present apparatus, by rotating the rod, the main stirring blade mounted vertically to the rod rotates in a plane perpendicular to the rod axis.
An auger-shaped auxiliary stirring blade incorporated in the main stirring blade and provided around an axis along the longitudinal direction of the main stirring blade is rotated. Thereby, the ground and the solidifying agent can be stirred and mixed densely. In the present specification, the “auger shape” refers to a shape in which a band is spirally wound around a shaft, and a band formed by winding a band around a member serving as a shaft, and only a band without a shaft member. Helically formed. The rotation of the auger-shaped auxiliary stirring blade prevents the soil from adhering to the main stirring blade and, at the same time, has the effect of transferring the soil outward in the radial direction of the stirring rod. It also contributes to the stirring.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described by showing embodiments of the present invention in detail.

FIG. 1 and FIG. 2 are schematic sectional structural views of an embodiment of the ground improvement apparatus according to the present invention. FIG. 1 is a cross-sectional view of the rod body at the position of the main stirring blade, and FIG.
FIG. 4 is a longitudinal sectional view near the tip of a rod body. The ground improvement apparatus 10 of this embodiment includes a rod 11 and a solidifying agent transfer pipe 30 built in the rod 11, and the solidifying agent transfer pipe 30 is provided near the tip of the rod 11.
On the outer circumference of the solidifying agent. A drill bit 16 is provided at the tip of the rod body. In the present specification, for the sake of convenience, the excavation bit side of the rod body 11 is referred to as “front end side” or “lower side”, and the opposite side is referred to as “rear end side”.
Alternatively, it is expressed as “upper side”. Ground improvement device 1 of FIG.
No. 0 has a pair of main stirring blades 12 for performing mechanical stirring. The pair of main stirring blades 12 are substantially rectangular flat plates provided on the opposite sides of the axis of the rod body 11 above the injection port 18 and extending perpendicular to the axis of the rod body 11. It has a shape. These pair of main stirring blades 1
2 rotates in a plane perpendicular to the rod body axis with the rotation of the rod body 11. That is, by rotating so as to cut the target ground horizontally, the injected solidifying agent and the ground are stirred.

A feature of the present invention is that, as shown in FIG. 1, a substantially rectangular notch 14 is formed in the main stirring blade 12 along its longitudinal direction, and an auger-shaped auxiliary stirring blade 20 is formed therein. It is that was installed. The auger-shaped auxiliary stirring blade 20 shown in FIG. 1 includes an auxiliary stirring shaft 22 that extends in the longitudinal direction of the cutout portion 14 and rotatably supports both ends 22 a and 22 b thereof. And a band material 24 spirally wound around.

Such an auger-shaped auxiliary stirring blade 20
However, when rotating around the auxiliary stirring shaft 22,
The spiral strip 24 rotates and cuts the surrounding ground in a direction other than horizontal, thereby preventing sediment from adhering to the main stirring blades 12 and significantly improving the stirring effect. Also, when such a spiral strip 24 is rotated in a predetermined direction,
The effect of transferring the earth and sand striking the surface of the band member 24 to the outside in the radial direction of the rod body 11 is produced, and there is an effect of preventing the adhesion of the earth and sand around the rod body 11.

In the embodiment shown in FIGS. 1 and 2, the rotation drive mechanism for rotating the auxiliary stirring blade 20, that is, the auxiliary stirring shaft 22, utilizes the transfer pressure of the solidifying agent. That is, inside the solidifying agent transfer pipe 30, the auxiliary stirring blade 20
The impeller 40 is installed at the same altitude as the above. The impeller 40 includes a wing portion 42 composed of four wings and a shaft portion 4 in this example.
And 4. The rotation of the impeller 40 is transmitted to the shaft 22 of the auxiliary stirring blade 20 by connecting the shaft portion 44 of the impeller 40 to the shaft 22 of the auxiliary stirring blade 20. FIG.
FIG. 2 is a schematic enlarged longitudinal sectional view showing an AA section in FIG. 1. When the solidifying agent (arrow 32) transferred at a high pressure hits the wing portion 42 of the impeller 40, the impeller 40 is rotated by the falling energy (arrow 43). In this example, the impeller 40 is housed in an impeller casing 46 formed by expanding the diameter of the solidifying agent transfer pipe 30, but the method of installing the impeller 40 is limited to this structure. Absent.

In addition to the mechanism using the solidifying agent as the energy fluid for rotating the impeller 40, another mechanism may use a compressed air transfer pipe provided separately from the solidifying agent transfer pipe. In this case, an impeller is installed in the middle of the compressed air transfer pipe, and the impeller is rotated by the transfer pressure of the compressed air. In this manner, the braking of the auxiliary rotor can be performed completely independently of the injection control of the solidifying agent.

FIG. 4 is a view showing still another mechanism for rotating the impeller 40. As shown in FIG. Instead of using the pressure fluid as described above, the axis of the auxiliary rotor 20 is
And rotate it. This auxiliary rotor 20
The braking motor and the control device thereof may be incorporated in the driving device of the ground improvement device 10 installed on the ground.

When the auxiliary rotor is rotated by the impeller, the rotation speed and torque can be controlled by adjusting the pressure of the pressurized fluid. Also, when using a motor,
Further, the rotation speed and the torque can be easily controlled.

FIG. 5 is a view showing another embodiment of the shape of the auxiliary stirring blade according to the present invention. The auxiliary stirring blade 12 shown in FIG.
Reference numeral 0 denotes a structure in which there is no auxiliary stirring shaft in the auxiliary stirring blade shown in FIG. 1, and has a shape in which only the band member 124 is spirally wound. However, at both ends thereof, a shaft support portion 12 rotatably supported at both ends in the longitudinal direction of the cutout portion of the main stirring blade.
4a and 124b are provided. The auxiliary stirring blade 220 of FIG. 5 (B) is one in which intermittent blade pieces 224 projecting around the auxiliary stirring shaft 222 are spirally arranged. Such intermittent rotation of the wing pieces 224 will produce a finer ground cutting and stirring effect.

Although not shown, the number of auxiliary stirring blades installed in the notch of the main stirring blade is not limited to one, and a plurality of auxiliary stirring blades may be installed in parallel.

In the embodiment described above, the rod body having a pair of main stirring blades is shown. However, the auxiliary stirring blade according to the present invention can be installed regardless of the number and position of the main stirring blades.
It is also possible to independently control the auxiliary stirring blades installed on each main stirring blade. For example, changing the direction of rotation or changing the speed of the left and right auxiliary stirring blades. Further, depending on the viscosity of the ground, the auxiliary stirring blades can be appropriately stopped.

FIG. 6 is a view showing a construction state of the ground improvement apparatus according to the present invention configured as described above. When the rod body 11 is rotated using the driving device 80, the main stirring blade 12 also rotates in a plane perpendicular to the axial direction of the rod body 11. Then, when a motor (not shown) is driven, the auxiliary stirring blade is rotated about the longitudinal direction of the main stirring blade 6 as an axis, and the ground is cut in a direction other than the above-mentioned plane to be stirred with the solidifying agent. Thus, the columnar ground improvement body 60 having uniform strength is formed by effective stirring and mixing.

[0026]

According to the ground improvement apparatus of the present invention, the circling phenomenon can be effectively prevented, and the ground and the solidifying agent can be densely stirred and mixed. Further, it is possible to prevent the viscous soil from adhering to the main stirring blade. As a result, the stirring time can be shortened because the stirring efficiency is improved. In addition, there is no variation in the strength of the ground improvement body, and the uniformity can be achieved.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional configuration view of an embodiment of a ground improvement device according to the present invention, and is a cross-sectional view at a position of a main stirring blade of a rod body.

FIG. 2 is a longitudinal sectional view of the vicinity of a tip end of a rod body in the embodiment of the ground improvement device of the present invention in FIG. 1;

FIG. 3 is a schematic enlarged longitudinal sectional view showing an AA section of FIG. 1;

FIG. 4 is a view showing still another mechanism for rotating an impeller for rotating an auxiliary stirring blade in the present invention.

FIGS. 5A and 5B are diagrams showing another embodiment of the shape of the auxiliary stirring blade according to the present invention.

FIG. 6 is a schematic side view showing a construction state in the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Ground improvement apparatus 11 Rod body 12 Main stirring blade 14 Notch part 16 Drilling bit 18 Injection port 20, 120, 220 Auxiliary stirring blade 22 Auxiliary stirring shaft 24 Strip 30 Solidification agent transfer pipe 40 Impeller 42 Blade part 44 Shaft part 46 impeller casing 50 motor or gear 60 ground improvement body 70 ground 80 drive

Claims (5)

[Claims] In order to form a ground improvement body by injecting and stirring a solidifying agent by mechanical stirring into soft ground,
A rod body, a solidifying agent transfer pipe built in the rod body to transfer the solidifying agent, an injection port of the solidifying agent opened on the outer periphery in the vicinity of the rod body tip, and the rod body shaft above the injection port. A ground improvement device comprising: a main stirring blade extending perpendicularly to the rod body and rotating with rotation of the rod body; a notch formed in a substantially rectangular shape from a base to a tip of the main stirring blade. Part, an auxiliary stirring shaft that is passed in the longitudinal direction of the notch portion and rotatably supported at both ends thereof, and an auxiliary stirring blade made of a band material spirally wound around the auxiliary stirring shaft, A rotation drive mechanism for rotating the auxiliary stirring blades with the auxiliary stirring shaft as the axis of the auxiliary stirring blades. 2. In order to form a ground improvement body by injecting and stirring a solidifying agent into soft ground by mechanical stirring,
A rod body, a solidifying agent transfer pipe built in the rod body to transfer the solidifying agent, an injection port of the solidifying agent opened on the outer periphery in the vicinity of the rod body tip, and the rod body shaft above the injection port. A ground stirrer provided vertically with respect to the main body and rotating with the rotation of the rod body, wherein a notch formed in a substantially rectangular shape from a base to a tip of the main stirrer. An auxiliary stirring blade that is made of a band material wound in a spiral shape, is passed in the longitudinal direction of the notch portion, and is rotatably supported at both ends thereof; and the auxiliary stirring blade of the spiral shape has a spiral shaft. A ground improvement device having a rotation drive mechanism for rotating the auxiliary stirring blade as a shaft. 3. The rotating drive mechanism includes an impeller provided in the solidifying agent transfer pipe, the impeller rotating by receiving a transfer pressure of the solidifying agent, and a shaft of the auxiliary stirring blade. The ground improvement device according to claim 1 or 2, further comprising: a shaft connected to the auxiliary stirring blade and connected to the auxiliary stirring blade. 4. The rotary drive mechanism has a transfer pipe for transferring compressed air and an impeller provided in the transfer pipe, wherein the impeller rotates by receiving a transfer pressure of the compressed air. The ground improvement apparatus according to claim 1, further comprising: a shaft connected to a shaft of the auxiliary stirring blade and transmitting rotation of the blade to the auxiliary stirring blade. 5. The ground improvement device according to claim 1, wherein the rotation drive mechanism has a motor.