JP2004169374A - Agitating mixing device for soil improvement - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an agitating mixing device for a soil improvement being adapted to verious grounds, having excellent agitating-mixing properties and being composed of a simple structure. <P>SOLUTION: The agitating mixing device 10 has first and second planar corotation preventive blades 6 and 7 rotatably connected to an agitating shaft 2 between an excavating blade 1 and an agitating blade 3. Approximately rectangular tabular projecting members 9 extended in the axial direction of the shaft 2 are installed near the shaft 2 in the blade 6. A discharge opening 12 is formed to the shaft 2, and a curing material introduced through the shaft 2 from an upper section is discharged from the opening 12. Openings among the front ends 9a of the projecting members 9 and the blade 3 and openings among the front ends 9b of the members 9 and the blade 1 are made narrower than that between the blade 6 and the blade 3 and that between the blade 6 and the blade 1 respectively by the members 9. Soil lumps turned in an accompanying manner together with the shaft 2 in excavated soil collide with the stopped projecting members 9, and are peeled from the blade 1, the blade 3 and the agitating shaft 2. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a stirring and mixing device for ground improvement for stirring and mixing soil on a ground and a hardening material injected into the ground, and relates to a stirring and mixing device mounted on a ground improvement construction machine for use.
[0002]
[Prior art]
In the soil improvement method of improving the soft ground by stirring and mixing the soil of the ground and the hardened material, the so-called corotation phenomenon in which the viscous soil adheres to the stirring and mixing device of the soil improvement construction machine and rotates with the stirring shaft Occurs.
Therefore, Patent Literature 1 describes a drilling and stirring device including a plurality of counter-rotating wings in order to prevent a counter-rotation phenomenon and enhance stirring and mixing performance. In this apparatus, a rotation preventing blade having a diameter slightly larger than that of the stirring blade and rotatably connected to the stirring shaft is provided between a plurality of stirring blades fixed to the stirring shaft.
Further, Patent Document 2 discloses an excavating and stirring apparatus in which vertical blades are provided on stirring blades adjacent to the counter-rotating wings so as to improve the ground having uniform strength characteristics as a whole while preventing a turning phenomenon. Has been described. This device three-dimensionally stirs and mixes the earth mass between the stirring blade and the anti-rotation blade by the rotation of the stirring blade on the horizontal plane and the rotation of the vertical blade on the vertical plane.
[0003]
[Patent Document 1]
JP-A-8-226120 (page 2-3, FIG. 1)
[Patent Document 2]
JP-A-7-197443 (page 2-3, FIG. 1)
[0004]
[Problems to be solved by the invention]
However, just by arranging a plurality of counter-rotating blades between the stirring blades as in the device described in Patent Literature 1, the counter-rotating blades are located near the center of the stirring blade, near the stirring shaft near the junction of the stirring shaft. The phenomenon remains, and there is a problem that the earth mass rotates while being attached to the stirring blade or the stirring shaft. This tendency is particularly large in highly viscous soils and fibrous humus soils.
[0005]
On the other hand, the apparatus described in Patent Literature 2 has a problem that the structure of the stirring blade becomes complicated because the vertical blade rotates on a vertical plane using the stirring blade rotating on a horizontal plane as a rotation support portion. In addition, the rotating support of the stirring blade receives stirring resistance from the soil due to the rotation of the stirring blade, and also receives stirring resistance from the soil due to the rotation of the vertical blade. Yes, resulting in an expensive structure. In particular, when a ground having a large stirring resistance such as a viscous clayey soil is to be subjected to ground improvement, it is necessary to use a stirring blade having sufficient strength.
Furthermore, since a large number of vertical blades are provided on the stirring blade, resistance when the device penetrates into the soil is large, and a large load tends to be applied to the driving portion of the stirring shaft.
In addition, when there are obstacles such as concrete waste, rebar scraps, wires, and cobblestones on the ground to be improved, since the stirring blade has a complicated mechanism, these obstacles are entangled with the stirring blade, or The device is caught between the stirring blade and the rotation preventing blade, and the device does not operate. At this time, it takes a lot of time to remove these obstacles from the apparatus, and the operation efficiency of the apparatus is impaired.
[0006]
The present invention has been made to solve such a problem, and is suitable for various types of soil such as viscous clayey soil and fibrous humus soil, and has an improved stirring and mixing property and a ground improvement having a simple structure. It is an object to provide a stirring and mixing device for use.
[0007]
[Means for Solving the Problems]
The ground improvement stirring and mixing apparatus according to the present invention includes a stirring shaft, a stirring blade fixedly provided around the stirring shaft, and provided adjacent to the stirring blade and rotatably connected to the stirring shaft. In the ground improvement stirring and mixing device for stirring and mixing the soil of the ground and the hardening material to be injected into the ground, the stirring wing rotates with the stirring shaft, and the rotation prevention member includes: At least one or more protruding members extending in the axial direction of the stirring shaft toward the stirring blade and protruding from the rotation prevention member are provided near the stirring shaft.
[0008]
It is preferable that a plurality of stirring blades are provided with the rotation preventing member interposed therebetween, and the protruding members protrude toward the respective stirring blades.
Two sets of stirring shafts and corresponding stirring blades may be provided so that the rotation preventing member is rotatably connected to each stirring shaft.
Further, a discharge port for injecting the hardening material into the ground may be provided, and a hardening material injection member capable of changing the position of the discharge port in a radial direction of the stirring shaft may be provided.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
Embodiment 1 FIG.
FIG. 1 shows the configuration of a ground improvement stirring and mixing apparatus according to Embodiment 1 of the present invention.
The stirring and mixing apparatus 10 includes a stirring shaft 2 connected to a ground improvement construction machine having a driving mechanism (not shown), and a drilling head 13 for drilling the ground mounted on one side. Around the stirring shaft 2, an excavating blade 1 and stirring blades 3, 4, 5 rotating integrally with the stirring shaft 2 are provided fixed to the stirring shaft 2. The excavation wing 1 has excavation teeth on one side, and excavates the soil together with the excavation head 13 and agitates the excavated soil. In other words, the excavating blade 1 has a function of both the excavating head and the stirring blade, and the excavating blade 1 alone constitutes one stirring blade.
The stirring blades 3, 4, and 5 are rod-shaped bodies having substantially the same outer diameter as the excavating blade 1, and rotate a plane perpendicular to the stirring shaft 2 to stir the soil.
[0010]
Between the excavating blade 1 and the stirring blade 3, there is provided a first flat counter-rotating blade 6 having a boss portion 6 a as a rotation preventing member and rotatably connected to the stirring shaft 2. ing. Further, a boss portion 7a is provided between the stirring blades 4 and 5 as a rotation preventing member in the same manner as the first rotation preventing blade 6, and is a flat plate-shaped member rotatably connected to the stirring shaft 2. Are provided. In this way, the stirring blades 3 and 4 are continuously arranged with a phase shift of 90 ° above the first rotation preventing blade 6, and the second rotation preventing blade 7 is further above the stirring blade 4. It is configured to be arranged.
[0011]
A pair of rings 8 are fixedly provided on the stirring shaft 2 at upper and lower positions of the boss portions 6a and 7a, and the first and second rotation preventing blades 6 and 7 do not move in the axial direction of the stirring shaft 2 respectively. It is configured as follows. Further, the first and second anti-rotation blades 6, 7 have an outer diameter larger than that of the stirring blades 3, 4, 5, and are configured so that their tips 6b, 7b bite into the soil. Therefore, while the excavation wing 1, the stirring wings 3, 4, 5 and the excavation head 13 are propelled in the soil while rotating, the first and second anti-corotation wings 6, 7 do not rotate. Promote in the soil.
[0012]
Further, the first rotation prevention blade 6 is provided with two substantially rectangular plate-shaped projecting members 9 extending in the axial direction of the stirring shaft 2 near the stirring shaft 2.
As shown in detail in FIG. 2, the projecting member 9 extending in the vertical direction is fixed to the first rotation prevention wing 6 by a bolt 11.
The projecting member 9 has both tip portions 9a and 9b forming an obtuse angle of about 120 to 150 °, and is slightly sharp.
FIG. 2 shows a case where the rotating stirring blade 3 has just passed above the projection member 9, and the distance S 1 between one end 9 a of the projection member 9 and the stirring blade 3 is about 5 to 8 cm. On the other hand, the distance L1 between the rotation preventing blade 6 and the stirring blade 3 is about 10 to 15 cm, and the ratio of the distance S1 to the distance L1 is about 0.3 to 0.8. .
[0013]
The distance M1 from the center position of the projection member 9 to the center axis g of the stirring shaft 2 is about 10 to 30 cm, and about 5 to the distance N1 from the outer periphery of the stirring blade 3 to the center axis g of the stirring shaft 2. ４０40% position. Further, the distance S2 between the other tip 9b of the projection member 9 and the excavation wing 1 is about 5 to 8 cm. On the other hand, the distance L2 between the rotation preventing blade 6 and the excavation blade 1 is about 10 to 15 cm, and the ratio of the distance S2 to the distance L2 is about 0.3 to 0.8.
Further, the second rotation prevention wing 7 is also provided with a protruding member 9 similarly to the first rotation prevention wing 6.
The positional relationship between the protruding member 9 of the second anti-rotational wing 7 and the stirring blades 4 and 5 disposed above and below the protruding member 9 of the first anti-rotational wing 6 is arranged above and below. This is the same as the positional relationship between the excavating blade 1 and the stirring blade 3.
[0014]
On the other hand, the stirring shaft 2 is provided with a discharge port 12 near the excavation wing 1. The discharge port 12 discharges the curing material guided through the stirring shaft 2 from above. This hardening material is a coal ash-based or cement-based material and is in a slurry state.
[0015]
Next, a ground improvement method performed by using the stirring and mixing device 10 according to this embodiment will be described with reference to FIG.
The stirring shaft 2 is rotated downward by the drive mechanism of the ground improvement construction machine, and while the hardening material is ejected from the discharge port 12 at the tip, the stirring shaft 2 is moved downward. Excavate. When the excavating head 13 and the excavating wing 1 are propelled downward in the ground E, an excavating hole having an excavating diameter corresponding to the outer diameter of the excavating wing 1 is formed. At this time, the rotation prevention wings 6, 7 having a diameter larger than the excavation diameter penetrate around the excavation hole and receive the resistance of the soil, and therefore proceed downward in the soil with the excavation without rotating.
[0016]
The earth mass excavated by the excavation head 13 and the earth wing 1 is partially mixed with the hardening material by the stirring blades 3, 4, and 5, and partly by the viscosity of the earth mass, the earth wing 1, the stirring blade 3, and the stirring shaft 2 are formed. Adhering to the periphery of the hardening material and being stirred and mixed with the hardening material. At this time, since the peripheral speed of the vicinity of the stirring shaft 2 of the excavating blade 1 or the stirring blade 3 is lower than that of the outer peripheral portion of the excavating blade 1 or the stirring blade 3, the earth mass is particularly likely to adhere.
However, since the protruding member 9 extends vertically from the counter-rotating wing 6 toward the excavating wing 1 and the stirring wing 3, the earth mass rotating with the stirring shaft 2 hits the stopped protruding member 9 and excavates. Peel off from blade 1, stirring blade 3 and stirring shaft 2.
[0017]
Therefore, the amount of soil mass adhering to the excavating wing 1, the stirring wing 3, and the stirring shaft 2 is reduced, so that the excavated soil is easily mixed and stirred with the hardening material. For this reason, the stirring and mixing accuracy, which is the mixing ratio of the excavated soil and the hardening material, is improved, and the amount of unconsolidated soil mass that does not mix with the hardening material is reduced.
When the ground improvement was performed using the stirring and mixing device 10 configured as described above, the coefficient of variation of the improved strength was reduced, but the degree of entanglement of the concrete galleries, gravel, reinforcing bars, etc. was not deteriorated, and the penetration resistance was also reduced. This was equivalent to a device using a rotation prevention wing without the projection member 9.
[0018]
Embodiment 2 FIG.
FIG. 3 shows a configuration of a ground improvement stirring and mixing apparatus 20 according to the second embodiment.
The stirring and mixing device 20 is a so-called two-shaft type stirring and mixing device in which two stirring shafts 22 each having a cutting head 21 at the tip are provided in parallel. Each stirring shaft 22 is provided with a cutting blade 24 that rotates integrally with the stirring shaft 22 above the cutting head 21. Above the excavation wing 24, a rod connecting plate 25 as a rotation preventing member, which is connected to the respective stirring shafts 22 at both ends, is provided. The rod connecting plate 25 is provided with a cylindrical boss portion 25a provided at both ends and loosely fitted to the stirring shaft 22, and a flat connecting portion 25b connecting the boss portions 25a to each other. They are freely connected.
The connecting portion 25b is provided with a rectangular flat plate-like projection member 26 on the outer peripheral side of the boss portion 25a, and is fixed to the rod connecting plate 25 by bolts 27. A pair of rings 28 are fixedly provided on the respective stirring shafts 22 at the upper and lower positions of the boss 25a, so that the rod connecting plate 25 does not move in the axial direction of the stirring shaft 22.
[0019]
An interval S3 between one tip 26a of the projection member 26 and the excavation wing 24 is about 5 to 10 cm. On the other hand, the interval L3 between the rod connecting plate 25 and the excavation wing 24 is about 15 to 35 cm, and the ratio of the interval S3 to the interval L3 is about 0.15 to 0.7.
The distance M2 from the center position of each projection member 26 to the center axis h of the corresponding stirring shaft 22 is about 20 to 30 cm, and the distance N2 from the outer periphery of the corresponding excavation wing 24 to the center axis h of the stirring shaft 22. , About 13 to 60%.
Also in the stirring and mixing device 20 configured as described above, the earth mass that rotates together with the stirring shaft 22 is separated from the stirring shaft 22 and the excavation wing 24 by the projection member 26 extending from the rod connecting plate 25.
[0020]
Therefore, similarly to Embodiment 1, the stirring and mixing accuracy is improved, and the amount of unconsolidated soil mass that does not mix with the hardening material is reduced. Further, since the rod connecting plate 25 does not need to be made to penetrate into the soil unlike the counter-rotating wings 6 and 7 of the first embodiment, the penetration resistance can be further reduced.
[0021]
Embodiment 3 FIG.
The ground improvement stirring / mixing device according to the third embodiment is arranged along the excavation wing 1 as shown in FIGS. 4 and 5, instead of the discharge port 12 provided in the stirring shaft 2 in the device of the first embodiment. A hardening material conveying pipe 32 having a plurality of discharge ports is arranged, and the other configuration is the same as that of the first embodiment.
[0022]
The hardened material conveying pipe 32 functions as a hardened material injection member, is bent into an L shape, passes through the stirring shaft 2, changes its direction near the excavation wing 1, and extends radially outward along the excavation wing 1. I have. The hardening material conveying pipe 32 is provided with four hardening material discharge ports 33, 34, 35, 36 near the central axis g of the stirring shaft 2 and at a predetermined radial distance from the central axis g. .
[0023]
Internal threads are formed in the discharge ports 33, 34, 35, 36. The outlets 33, 35 and 36 excluding the outlet 34 are plugged with male threads 37 and sealed. Therefore, in this case, the hardening material is discharged from the discharge port 34 that rotates on a circle having a radius of, for example, about 10 to 20 cm from the central axis g of the stirring shaft 2.
As described above, by moving the discharge position of the hardening material in the radial direction from the center axis g of the stirring shaft 2, the hardening material and the excavated soil are more easily mixed, and the stirring and mixing accuracy is further improved.
Further, by selecting a discharge port to be sealed with the plug 37 according to the properties of the ground to be improved, it is possible to discharge the hardening material from a circle having various radii.
[0024]
In the above-described first to third embodiments, the rotation prevention blade 6 and the rod connecting plate 25 as the rotation prevention member are arranged adjacent to the excavation blade 1, the stirring blade 3, and the like, but are not limited thereto. Instead, for example, the co-rotation prevention wing 6 provided with the projection member 9 and the rod connecting plate 25 provided with the projection member 26 may be arranged adjacent to the excavation heads 13 and 21. Thereby, it becomes easy to exfoliate the earth mass attached to the stirring shafts 2 and 22 immediately above the excavation heads 13 and 21.
Further, the projection members 9 and 26 are sharpened in the circumferential direction of the stirring shafts 2 and 22 so that rigidity according to the resistance received from the rotating earth mass is obtained, even if the cross-sectional shape cut in the horizontal direction is rectangular. It may have a chevron shape. Further, only one protrusion member 9 and 26 may be provided on the rotation prevention blade 6 and the rod connecting plate 25, or three or more protrusion members may be provided.
In the second embodiment, a stirring blade may be provided above the rod connecting plate 25 of the stirring shaft 22, and the projecting member 26 may have a shape further protruding above the rod connecting plate 25. Accordingly, the earth mass attached above the rod connecting plate 25 of the stirring shaft 22 can be peeled off, and the stirring and mixing accuracy is further improved.
[0025]
【The invention's effect】
According to the stirring and mixing device for ground improvement according to the present invention, the co-rotation preventing member includes a protruding member that extends toward the stirring blade side toward the axial direction of the stirring shaft near the stirring shaft and protrudes from the co-rotation preventing member. Since at least one or more are provided, it is possible to provide a stirring and mixing apparatus which is suitable for various types of ground such as viscous clayey soil and fibrous humus soil, has excellent stirring and mixing properties, and has a simple structure.
[Brief description of the drawings]
FIG. 1 is a side view showing a structure of a stirring and mixing device for ground improvement according to Embodiment 1 of the present invention.
FIG. 2 is a partially enlarged side view showing a main part of FIG.
FIG. 3 is a side view showing a structure of a stirring and mixing device for ground improvement according to Embodiment 2 of the present invention.
FIG. 4 is a side view showing a structure of a main part of a stirring and mixing device for ground improvement according to Embodiment 3 of the present invention.
FIG. 5 is a view as seen from the direction of arrow A in FIG. 4;
[Explanation of symbols]
1,24 ... Excavation blade (stirring blade), 2,22 ... Stirring shaft, 3,4,5 ... Stirring blade, 6,7 ... Turning prevention wing (Turning prevention member), 9,26 ... Protrusion member, 12 , 33, 34, 35, 36: discharge port, 25: rod connecting plate (rotation prevention member), 32: hardened material conveying pipe (hardened material injection member), E: ground.

Claims (4)

A stirring shaft,
A stirring blade fixedly provided around the stirring shaft,
It is provided adjacent to the stirring blade, and comprises a rotation preventing member rotatably connected to the stirring shaft,
The stirring blade is rotated together with the stirring shaft, in the ground improvement stirring and mixing device for stirring and mixing the soil of the ground and the hardening material to be injected into the ground,
In the vicinity of the stirring shaft, at least one or more protruding members extending toward the stirring blade side in the axial direction of the stirring shaft and protruding from the rotation preventing member are provided in the vicinity of the stirring shaft. A stirring and mixing device. The stirring and mixing device according to claim 1, wherein a plurality of the stirring blades are provided with the rotation preventing member interposed therebetween, and the protruding members protrude toward the respective stirring blades. Comprising two sets of the stirring shaft and the corresponding stirring blade,
The stirring and mixing device according to claim 1 or 2, wherein the rotation preventing member is rotatably connected to each of the stirring shafts. 4. The apparatus according to claim 1, further comprising a discharge port configured to inject the hardening material into the ground, and a hardening material injection member configured to change a position of the discharge port in a radial direction of the stirring shaft. 5. Stirring and mixing equipment.

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