JP2008111246A5 - - Google Patents

Description

Single-shaft mixing and stirring device for ground improvement

  The present invention relates to a single-shaft mixing and stirring device for ground improvement, and more particularly to a single-shaft mixing and stirring device used in a method for forming a pile on the ground and improving the ground.

When building a structure by improving the ground in a place where the strength of the ground such as soft ground or landfill is relatively weak, there is a method of driving piles manufactured by concrete etc., but there is a noise problem Etc. are being shunned.
On the other hand, instead of the construction method, a method of excavating a hole in the ground, injecting an injection material (solidifying material) called cement, a coagulant or a hardener into the excavated soil, and forming a pile by mixing and stirring (place) The pile construction method is being carried out.
Conventionally, a base machine or the like is used for excavating the hole, and a plurality of stirring bodies such as a plurality of stirring rods are arranged in a direction perpendicular to the axis in the vertical direction of a single axis (single axis) rotation axis (stirring axis). A solidified material such as excavated soil and hardener as described above while projecting and rotating the stirring bodies such as a plurality of stirring rods integrally (both together) with the rotation of the rotary shaft and injecting the hardener. Is used to improve the ground by stirring and kneading.
However, a plurality of stirrers such as a plurality of stirrers are projected in a direction perpendicular to the axis in the vertical direction of the conventional single-axis rotation shaft described above, and the plurality of stirrers such as the stirrer bars are attached to the rotation shaft. In the ground improvement device that rotates together with the rotation, all of the plurality of stirring rods rotate integrally with the rotation shaft, so that the so-called joint rotation phenomenon that the excavated soil rotates integrally with the coaxial occurs sufficiently. When the hardener is difficult to knead, especially when the ground is made of viscous soil, the excavated soil will be in a dumpling state that wraps the stir bar, and stirring and kneading cannot be performed at all. There was a drawback that there was.
Therefore, the rotating shaft for stirring is composed of a double shaft of an outer shaft and an inner shaft rotating in opposite directions, and a stirring blade is attached to each of the inner and outer shafts, and they are rotated in opposite directions on the inner and outer sides. A ground improvement device is proposed.
For example, Japanese Patent Application Laid-Open No. 11-81297 discloses a ground improvement device that reversely rotates an outer shaft 501 and an inner shaft 502 as shown in FIG. 5, and a surrounding blade 503 is attached to the outer shaft 501, A ground improvement device has been proposed in which the surrounding wing 504 is attached to the inner shaft 502 and the surrounding wing 503 and the surrounding wing 504 are rotated in opposite directions to improve the ground.
As an improvement of the above patent, Japanese Patent Application Laid-Open No. 2002-332632 discloses a ground constituted by a double shaft of an outer shaft 600a and an inner shaft 600b rotating in opposite directions as shown in FIG. An improved apparatus, in which an upper stirring blade 601 and a lower stirring blade 603 (having comb teeth 602) are attached to the outer shaft 600a, while an inverted L-shaped surrounding blade 604 and a drilling stirring blade 606 (comb) are attached to the inner shaft 600b. Teeth 605), rotate the inner shaft 600b, perform excavation by the excavating member 607, rotate the inverted L-shaped surrounding blade 604, the comb teeth 605, and the excavation stirring blade 606 attached to the inner shaft 600b, On the other hand, the outer shaft 600a is rotated in the opposite direction to the inner shaft 600b, and the upper stirring blade 601, the comb teeth 602, and the lower stirring blade 603 attached to the outer shaft 600a are rotated to improve the ground. Soil improvement apparatus has been proposed.
However, in the ground improvement device configured on the double shaft, an internal / external double tube is required, and a rotary transmission shaft is required to rotate the internal / external double tube in the reverse direction. There are disadvantages such as necessity, high cost, the ratio of internal and external rotational speeds when determining the rotational speed, and difficulty in assembly and disassembly.
JP-A-11-81297, JP-A-2002-332632

An object of the present invention is to provide a ground improvement device using a single-axis (single-axis) rotating shaft (stirring shaft) for providing a technique capable of eliminating the disadvantages of the above-described conventional technology, and the conventional ground described above. An object of the present invention is to provide a ground improvement device capable of further improving the mixing and stirring device and achieving an efficient ground improvement.
Other objects and novel features of the present invention will become apparent from the description of the present specification and the drawings.

The claims of the present invention are as follows.
(Claim 1) In a mixing stirrer used in a construction method for excavating the ground while rotating a drilling member, mixing excavated soil and solidified material to form a pile in the ground and improving the ground, The stirring shaft is provided with vertical blades on the inner side, a rotary stirring member that has a square-shaped cross section and rotates as the stirring shaft rotates, and has vertical blades at both ends inside the rotating stirring member. A fixed stirring member that does not rotate even if the shaft rotates, and a fixed blade that does not rotate even if the stirring shaft rotates is connected to the lower portion of the rotating stirring member. A ground improvement single-shaft mixing and stirring device.

According to the present invention, in a place where the strength of the ground is weak, such as soft ground or landfill, when the ground is improved and a building is constructed, a hole is excavated in the ground and the solidified material is applied to the excavated soil. In the method of injecting and forming piles by mixing and stirring, it is possible to provide a ground improvement device with a single shaft stirring shaft, so there is no need for inner and outer double pipes like a ground improvement device configured with a double shaft, and a single shaft It is possible to rotate with a stirring shaft, and the ground improvement device configured with a double shaft requires a rotation transmission shaft to reversely rotate the inner and outer double pipes. Good, the ground improvement device configured with a double shaft required a dedicated machine for that purpose, but a general-purpose machine is sufficient, assembly and disassembly is easy, and it can be provided at a low cost. There are advantages.
Further, according to the present invention, the ground improvement device with a single-shaft stirring shaft performs primary horizontal stirring and secondary horizontal and vertical stirring, so that efficient ground improvement can be achieved. It can be performed, the shearing force is greatly improved, the co-rotation phenomenon and the effect of preventing dumping of the excavated soil are greatly improved, and even when the hardener is difficult to knead like a ground made of clay soil Good stirring and kneading is performed, excavation speed is improved, ground improvement work can be completed in a shorter period of time, and powdery hardener is used for ground with high water content such as tidal flats Even in this case, good stirring and kneading can be performed.
Furthermore, according to the present invention, the excavation member, the rotary stirring member, the fixed stirring member and the like are assembled as independent parts, so that the parts can be easily replaced depending on the degree of damage. It is like that.

  Next, embodiments of the present invention will be described with reference to the drawings.

Embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 2, the ground improvement single-shaft mixing / stirring apparatus X of the present invention can be separated into each component (part), and the whole is assembled by the part as shown in FIG. be able to. Therefore, it is easy to disassemble and maintain each part, and the parts can be easily replaced depending on the degree of damage.
As shown in FIG. 2 (D), a digging member 2 is attached to the lower part of a uniaxial stirring shaft (rotating rod, rotating shaft, excavating shaft) 1 in the single-shaft mixing and agitating apparatus X of ground improvement. The excavation member 2 includes, for example, an excavation bit 200 and excavation blades 201 .
As shown in FIG. 2D, a discharge port 3 is provided in the center of the excavation member 2, and the solidified material is discharged from the discharge port 3 and mixed with the excavated soil.

As shown in FIG. 2 (B), the rotary stirring member 4 has a square-shaped cross section and is provided with vertical blades 400 inside thereof. In the illustrated example, the vertical blades 400 are installed toward the inner side of the rotary stirring member 4 with an appropriate interval in the vertical direction. The rotary stirring member 4 has a square-shaped cross section as a whole, but two of the components having a U-shaped cross section that is half of the rotary stirring member 4 are connected by upper and lower connecting members 401 and 402. Can be linked.
A fastening hole 4010 is formed in the center of the upper connecting member 401.
When assembling the single-shaft mixing and stirring device X for ground improvement, the upper and lower connecting members 401 and 402 of the rotating stirring member 4 are attached to the rotating rod 1, and the fastening hole 4010 at the center of the upper connecting member 401 and FIG. As shown in FIG. 2 (D), the fastening hole 100 opened in the upper part of the rotating rod 1 is aligned, and the rotating stirring member 4 is attached to the rotating rod 1 with the fixing pin P. The upper and lower connecting members 401 and 402 also serve as attachment members of the rotary stirring member 4 to the rotary rod 1.

As shown in FIG. 2A, the fixed stirring member 5 includes vertical blades 500. In the illustrated example, the vertical blades 500 are installed at both ends of the horizontal blade 501 of the rotary stirring member 4 with an appropriate interval between the vertical blades 500 in the vertical direction.
A mounting member 502 for the rotating rod 1 is provided at the center of the horizontal blade 501.
In the illustrated example, the horizontal blade 501 shows an example composed of four blades.

The fixed stirring member 5 and the fixed blade 6 shown in FIG. 2 (C) are connected via a connecting member 7.
The fixed blade 6 is configured in a rectangular shape as illustrated, for example.
As shown in FIG. 2 (C), the fixed blur - the central part of the de 6, recesses 601 are provided, the fitting causes the protrusion 701 of the lower end portion of the connecting portion material 7 in the recess 601. The fixed blade 6 may be attached to the lower end portion of the continuous member 7 by welding or the like.
The fixed stirring member 5 is attached to the continuous member 7. The mounting member 502 of the fixed stirring member 5 is attached to the continuous member 7 and is fastened and fixed with a bolt B.

As shown in FIG. 1, a rotating stirring member 4 having a vertical blade 400 inside and having a square-shaped cross section is attached to a single-shaft stirring shaft 1, and vertical blades 500 are attached to both ends inside the rotating stirring member 4. The fixed stirring member 5 having the horizontal blades 501 is attached, and the fixed blade 6 is connected to the lower portion of the rotating stirring member 4 via the connecting member 7.
As shown in FIG. 1, the vertical blades 500 at both ends of the fixed stirring member 5 are positioned outside the vertical blades 400 of the rotary stirring member 4.
The fixed blade 6 is installed near the upper part of the excavation member 2.

As shown in FIG. 3, in the single-shaft mixing and agitating device X of the ground improvement, the excavation member 2 rotates with the rotation of the rotating rod 1. The excavation member 2 rotates in the same direction as the rotation direction of the rotating rod 1.
A rotating stirring member 4 having a vertical blade 400 on the inner side and having a square-shaped cross section is attached to the rotating rod 1, and the rotating stirring member 4 rotates as the rotating rod 1 rotates. The rotating stirring member 4 rotates in the same direction as the rotating direction of the rotating rod 1.
Vertical blades 400 mounted on the inside of the rotary stirring member 4 rotate together with the rotating rod. 1 and rotating agitating member 4. The vertical blades 400 rotate in the same direction as the rotary rod 1 and the rotary stirring member 4.
The fixed stirring member 5 inside the rotating stirring member 4 is attached to the connecting member 7 so as not to rotate even if the rotating rod 1 rotates, so that the rotating rod 1 rotates. It is designed not to rotate.
The vertical blades 500 at both ends of the fixed stirring member 5 do not rotate even when the rotating rod 1 rotates.
The fixed blade 6 is connected to the fixed stirring member 5 via the connecting member 7, and does not rotate even if the rotating rod 1 rotates.
The fixed agitating member 5 and the fixed blade 6 do not rotate even when the rotating rod 1 rotates, but rotate freely and descend as the excavation progresses.

As shown in FIG. 3, as the single-axis rotating rod 1 rotates, the ground is excavated while the excavating member 2 is rotated, and the excavated soil and solidified material are mixed to form a pile in the ground. Although improving, the earth and sand dug up by the excavation member 2 rotate together with the solidified material (cement milk) discharged (spouted) from the discharge port 3.
Even if the single-axis rotating rod 1 rotates, the fixed agitating member 5, the vertical blades 500 of the fixed agitating member 5 and the fixed blade 6 rotate without rotating and descend downward.
The earth and sand dug up by the excavating member 2 rotate together with the solidified material (cement milk) discharged (spouted) from the discharge port 3, and the fixed blade 6 and the excavating member above and below the fixed blade 6. and between the fixed blur of 2 - primary horizontal agitation between de 6 and the rotary stirring member 4 is performed.
The earth and sand sent into the rotary stirring member 4 is subjected to secondary stirring by horizontal and vertical shearing action between the horizontal blades 501 and the vertical blades 500 attached to the fixed stirring member 5. .

  According to the present invention, even if the rotary rod 1 is configured as a single shaft, the primary horizontal stirring and the secondary horizontal and vertical stirring are performed as described above, so that the ground is efficiently improved. be able to.

Next, an example of application of the ground improvement single-shaft mixing and stirring device X of the first embodiment will be described with reference to FIG.
A stirring shaft 1 of a ground-improved single-shaft mixing stirrer X as shown in FIG. 1 is mounted below the drive motor 9 of the movable base machine 8, and the single-shaft stirring shaft 1 is mounted. , And drilling with primary horizontal agitation and secondary horizontal and vertical agitation as described above, drilling a circular columnar drilling hole perpendicular to the ground, solidifying material (hardening agent) Can be jetted from the discharge port 3 via the inside of the stirring shaft 1 to stir and knead the curing agent and excavated soil, thereby forming a ground improvement portion in the excavation hole and improving the ground.
According to the above embodiment, in a place where the strength of the ground is weak, such as soft ground or landfill, when the ground is improved and a building is constructed, a hole is excavated in the ground and the solidified material in the excavated soil In the method of forming a pile by mixing and stirring, since a ground improvement device with a single shaft stirring shaft 1 can be provided, there is no need for an inner / outer double pipe like a ground improvement device configured in a double shaft, It is possible to rotate with a single agitation shaft 1, and the ground improvement device configured as a double shaft requires a rotation transmission shaft to reversely rotate the inner and outer double pipes. The ground improvement device configured with a double shaft required a dedicated machine for that purpose, but a general-purpose machine is sufficient, assembling and disassembling is easy, and it is provided at low cost. There are advantages such as what you can do.
Moreover, according to the said Example, even if it is the ground improvement apparatus X in the single axis | shaft stirring shaft (rotary shaft) 1,
Primary horizontal agitation such as primary horizontal agitation between the upper and lower sides of the fixed blade 6 as described above and secondary agitation in the horizontal and vertical directions by the horizontal blades 501 and the vertical blades 500 inside the rotary stirring member 4 and Since secondary horizontal and vertical agitation is performed, the ground can be improved efficiently, the shearing force is greatly improved, and the effect of preventing the co-rotation phenomenon and the dumping of the excavated soil is greatly improved. Even when hardeners are difficult to knead like ground made of clay soil, good agitation kneading is performed, and further, excavation speed is improved and ground improvement work is completed in a shorter period of time. Even when a powdery curing agent is used on a ground having a high water content such as a tidal flat, good stirring and kneading can be performed.
Furthermore, according to the embodiment, the co-rotation phenomenon can be further prevented, and the co-rotation phenomenon can be solved regardless of the hardness of the ground.
Furthermore, according to the present invention, as shown in FIG. 2, since the excavation member 2, the rotary stirring member 4, the fixed stirring member 5 and the like are assembled as independent parts, each damage is caused. Depending on the condition, the parts can be easily exchanged.

The solidifying material used in the present invention can be used regardless of the name of cement, coagulant, solidifying material, hardener, etc., as long as it meets the purpose. Specific examples of the solidifying material Examples thereof include cement milk and silicate soda.

    The present invention can be modified as appropriate. For example, in the above-described embodiment, the example in which the two rotating stirring members 4 are configured is shown. . Moreover, although the example which provides the one fixed stirring member 5 was shown, you may install two or more fixed stirring members 5. FIG.

  INDUSTRIAL APPLICABILITY The present invention can be applied to all methods of excavating the ground while rotating excavating members, mixing the excavated soil and a solidified material to form a pile in the ground, and improving the ground.

It is a block diagram of the mixing improvement apparatus of the ground improvement which shows the Example of this invention. It is decomposition | disassembly explanatory drawing of the mixing stirring apparatus of the ground improvement which shows the Example of this invention. It is explanatory drawing of the mixing stirring apparatus of the ground improvement which shows the Example of this invention. It is a block diagram of the usage example of the mixing and stirring apparatus of the ground improvement which shows the Example of this invention. It is a block diagram of the mixing stirring apparatus of the ground improvement of a prior art example. It is a block diagram of the mixing stirring apparatus of the ground improvement of a prior art example.

1 Single-shaft stirring shaft (rotating rod)
2 Excavating member 4 Rotating stirring member 5 Fixed stirring member 400 Fixed blade 500 Vertical blade 501 Horizontal blade 6 Fixed blade X Single-axis mixing and stirring device for ground improvement