JP2918329B2 - Ground improvement equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a ground improvement device used for a ground improvement method for forming a columnar consolidated body in soft ground.

[Prior art] Conventionally, as an improvement method for soft ground, a stirrer blade is rotated to penetrate and pull out a target ground, and at that time, a chemical stabilizer such as a coal-based or cement-based material is supplied into the ground, There is known a method of forming a columnar consolidated body by stirring and mixing earth and sand cut in the ground and a chemical stabilizer.

As a ground improvement device used in such a ground improvement method, a long rotating shaft that rotates at a high speed by a driving source such as a motor is provided at a lower portion of a driving device main body, and a drill bit is provided at a tip of the rotating shaft, In general, a drilling blade is provided above a bit, a stirring blade is provided above the bit, and a discharge port for discharging a chemical stabilizer is provided near the drilling blade of the rotating shaft.

That is, this device drilled a hole in the ground with a drill bit by rotating a rotating shaft by a drive source, and then dig the ground by the rotating force of the drilling wing, and excavated by supplying a chemical stabilizer from the discharge hole. The ground is improved by mixing and mixing the soil and the chemical stabilizer with a stirring blade, and forming a columnar solidified body at the excavation site.

[Problems to be Solved by the Invention] However, in the above-mentioned ground improvement apparatus, when it is used, the so-called co-rotation phenomenon in which the soil excavated by the excavation wing rotates together with the stirring wing as a lump is likely to occur. ,
There is a problem in that sufficient mixing is not performed between the soil and the chemical stabilizer, so that the compact becomes inhomogeneous and its strength is reduced.

[Means for Solving the Problems] In the ground improvement apparatus of the present invention according to claim 1 of the present invention, a driving device main body having a driving source, and provided in the driving device and configured to be rotatable by the driving source. A rotating shaft, a main stirring blade provided on the rotating shaft, a cutting blade provided on the rotating shaft at a tip side of the main stirring blade, a discharge blade formed in the rotating shaft and near the cutting blade. A supply path for supplying a chemical stabilizer having an outlet, wherein the gear box having a rotation axis parallel to the rotation shaft between the main stirring blade and the excavation blade in the rotation shaft is rotated by the rotation. The rotating shaft is provided so as to be rotatable with respect to the shaft, and transmits the rotating force to the rotating shaft in a direction opposite to the rotating direction of the rotating shaft caused by a shift in rotation between the rotating shaft and the gear box. Providing a gear in each of the shaft and the gear box, and providing a sub-stirring blade on the rotating shaft is a means for solving the above problem.

[Operation] According to the ground improvement device of the first aspect, when the soil excavated by the excavation wing rotates together with the agitation wing in a lump state, the soil is stirred by the auxiliary agitation wing provided on the rotating shaft. By doing so, it can be suppressed.

[Embodiment] FIG. 1 shows an embodiment of a ground improvement device according to claim 1 of the present invention, and reference numeral 1 in FIG. 1 denotes a driving device main body having a driving source (not shown) such as a motor. It is. A rotary shaft 2 that can rotate in the forward and reverse directions by the drive source is attached to a lower portion of the drive device 1, and a drill bit 3 for making a hole in the ground is formed at the tip of the rotary shaft 2. Have been.

A drilling wing 4 is attached and fixed to the rotary shaft 2 in the vicinity of the drill bit 3, and the main stirring blades 5, 5 are located closer to the drive main body 1 than the drilling wing 4 of the rotary shaft 2.
Are attached and fixed at intervals and orthogonally to each other. Here, at the lower end of the excavation wing 4, an uneven excavation blade 4 a for excavating soil in the ground is formed.

Further, a supply path (not shown) for guiding the chemical stabilizer supplied from the ground (drive unit main body 1) side is formed in the rotary shaft 2, and the rotary shaft 2
In the vicinity of the excavation wing 4, a discharge port 6 of the supply path is formed.

A gear box 7 is mounted between the main stirring blade 5 and the excavating blade 4 on the tip end side of the rotary shaft 2 so as to be rotatable with respect to the rotary shaft 2 and not movable in the vertical direction. A main gear 8 is provided on the outer periphery of the rotating shaft 2 at a position where the gear box 7 is attached. This main gear 8 is connected to other gears in the gearbox 7.
The gears 9, 9 are in mesh with the auxiliary gears 11, 11 via the gears 10, 10, respectively. The rotating shafts 12, 12 protrude downward from the gearbox 7 (toward the distal end of the rotating shaft 2) and are attached and fixed to the auxiliary gears 11, in parallel with the rotating shaft 2. Sub stirring blades 13, 13 are attached to and fixed to the 12, 12, respectively, at intervals and orthogonally to each other.

In order to improve the soft ground by forming a columnar solidified body with such a ground improvement device, first, the driving source of the driving device main body 1 is driven to rotate the rotating shaft 2, and a hole is formed in the ground with the drill bit 3. Open. Further, the ground is excavated by the rotational force of the excavating wing 4, and the excavated soil and the chemical stabilizing material are supplied from the discharge hole 6 to supply the chemical stabilizing material to the main stirring blade 5,
Stir and mix according to 5. Then, the rotation of the rotating shaft 2 is transmitted through the main gear 8, so that the gear box 7 rotates in the same direction as the rotating shaft 2 by performing so-called co-rotation. However, when the gearbox 7 rotates in this manner, the gearbox 7 receives the resistance of the excavated soil and the chemical stabilizer in the ground, and its rotation is delayed by the rotation shaft 2. Then, the difference between the rotation of the rotating shaft 2 and the rotation of the gear box 7 is transmitted from the main gear 8 to the rotating shafts 12 and 12 via the gears 9 and 9 and the gears 10 and 10, whereby the rotating shafts 12 and 12 are rotated. The sub-agitating blades 13 are rotated in the direction opposite to the rotation direction of the rotating shaft. When the auxiliary stirring blades 13 and 13 rotate in this way,
The auxiliary stirring blades 13 and 13 are disposed between the excavating blade 4 and the main stirring blades 5 and thereby stir the soil excavated by the excavating blade 4 and the supplied chemical stabilizer. Therefore, the excavated soil is prevented from rotating together with the main stirring blades 5, 5 in a lump state.

Therefore, in this ground improvement device, the excavation wing 4
The so-called co-rotation phenomenon, in which the excavated soil rotates together with the main stirring blades 5, 5 as a lump, can be suppressed, so that the soil and the chemical stabilizer can be sufficiently mixed, and thus the consolidation formed The body can be homogenized to increase its strength.

In this embodiment, the gear box 7 is arranged between the main stirring blades 5, 5 and the excavating blade 4, but the gear box 7 may be arranged between the main stirring blades 5, 5. Of course.

Next, after confirming that the excavation has progressed to a predetermined depth, the discharge of the chemical stabilizer is stopped, and the rotating shaft 2 is rotated in the direction opposite to the direction at the time of excavation, and pulled up at a constant speed. Also in this case, it is needless to say that the co-rotation preventing effect can be obtained as in the case of excavation.

In this way, when the device is completely lifted, a high-quality columnar consolidated body homogeneously mixed can be formed at the excavation site in the ground.

In the above embodiment, the rotational speed of the rotating shafts 12, 12 can be adjusted to, for example, a high speed by appropriately adjusting the gear ratio of each gear in the rotating shaft 2 and the gear box 7. By increasing the rotation speed of the rotating shafts 12, 12, the construction time can be shortened as compared with the conventional method to obtain a columnar consolidated body having the same quality as that obtained by the conventional apparatus. Can be reduced.

[Effects of the Invention] As described above, the ground improvement device according to claim 1 of the present invention uses the rotation shaft to prevent the soil excavated by the excavation wing from rotating together with the stirring wing in a lump state. In this case, the soil and the chemical stabilizer can be sufficiently mixed, so that the formed compact can be homogenized and its strength can be increased.

[Brief description of the drawings]

FIG. 1 is a view showing one embodiment of the ground improvement device according to the first aspect of the present invention, and is a front view of the ground improvement device in a partially sectional view. DESCRIPTION OF SYMBOLS 1 ... Drive device main body, 2 ... Rotating shaft, 4 ... Drilling blade, 5 ... Main stirring blade, 6 ... Discharge port, 7 ... Gear box, 8 ... Main gear, 9,10 ... Gear , 11 …… secondary gear, 12…
… Rotary shaft, 13… Auxiliary stirring blade.

Continuation of the front page (56) References JP-A-63-194022 (JP, A) JP-A-63-2843111 (JP, A) JP-A-1-174719 (JP, A) Jpn. , U) (58) Field surveyed (Int.Cl. ⁶ , DB name) E02D 3/12 102

Claims (1)

(57) [Claims] 1. A driving device main body having a driving source, a rotating shaft provided in the driving device and configured to be rotatable by the driving source, a main stirring blade provided on the rotating shaft, A shaft provided with a drilling wing provided on the tip end side of the main stirring blade, and a supply path for supplying a chemical stabilizer formed in the rotary shaft and having a discharge port near the drilling wing. In the ground improvement apparatus, a gear box having a rotation axis parallel to the rotation shaft is provided between the main stirring blade and the excavation wing in the rotation shaft so as to be rotatable with respect to the rotation shaft. Gears are provided on the rotating shaft and the gear box, respectively, so as to transmit a rotating force in a direction opposite to a rotating direction of the rotating shaft caused by a rotation shift to the rotating shaft. A ground improvement device comprising a sub-stirring blade provided on the rotating shaft.