JP5782354B2 - Ground improvement device and ground improvement method using the same - Google Patents

Description

  The present invention relates to a ground improvement device for excavating the ground, adding a ground improvement material to the excavated portion, mixing with the excavated soil, and stirring the ground, and a ground improvement method using the ground improvement device.

Conventionally, as ground improvement work, excavating the ground into blocks or walls and loosening the ground, for example, adding ground improvement material, mixing with the loosened ground, stirring, etc. A construction method is known (see, for example, Patent Document 1).
In Patent Document 1, a plurality of rods are arranged so that adjacent excavation blades do not contact each other, and a stirring blade is provided above the excavation blade of each rod. The ground improvement is such that the stirring blade is rotated in a direction different from the rotation direction of the rod, and the excavation blade is rotated together with the rod to move downward in the ground while mixing and stirring by the stirring blade. An apparatus is disclosed.

  Further, as a general ground improvement device, a triaxial rod is moved downward in the ground, and a propeller-like kneading blade and a spiral moving blade are arranged on the rod, and these kneading blades There is a device in which the moving blades and the moving blades are alternately arranged so as not to interfere between adjacent rods. In this case, as shown in FIG. 11, the ground improvement regions M11 (broken lines) created by the rods overlap each other. For example, when constructing a ground improvement wall used as a temporary earth retaining wall, The area where the slab can be formed (the area indicated by reference numeral M10 in FIG. 11) is the effective cross section of the temporary retaining wall.

Japanese Patent Laid-Open No. 11-217820

However, in the conventional ground improvement device, as shown in FIG. 11, the adjacent ground improvement regions M11 and M11 are excavated by overlapping each other, and the portion outside the wall surface of the ground improvement wall does not have an effective cross section. That is, there is a problem that the effective cross section becomes smaller with respect to the improved diameter. Therefore, a part of the circular shape improved by excavation with the excavating blade corresponds to an extra excavation portion that does not function as an effective cross section, and the ground improvement portion is wasteful, so that cost reduction has been demanded.
In recent years, there has been an increasing demand for ground improvement work in narrow spaces in urban areas, and there has been a need for a simple and downsized structure, and there is room for improvement in that respect.

  The present invention has been made in view of the above-described problems, and a ground improvement device capable of reducing cost by eliminating excessive excavation of the ground improvement portion with a simple structure, and ground improvement using the same. It aims to provide a method.

In order to achieve the above object, the ground improvement device according to the present invention is a ground improvement device that performs ground improvement by moving in the ground, and is rotated around a vertical axis and provided in parallel with each other. A rotating shaft, a first excavating blade fixed to the lower end of the first rotating shaft and rotating horizontally, and arranged between the adjacent first rotating shafts in parallel to the first rotating shaft, the rotation of the first rotating shaft is A second rotating shaft that is transmitted and rotates about the vertical axis, a second excavating blade that is fixed to the lower end of the second rotating shaft and rotates in the horizontal direction, and has a smaller diameter than the first excavating blade, and the first excavating blade And a side cutter that is located in a cross-sectional area that is not excavated by the second excavating blades and that is provided along a common circumscribing line of the rotation trajectory of the adjacent first excavating blades, and the side cutter has a thickness of the ground improvement device. It is arranged on both sides across the second rotation axis in the vertical direction, and from below And than the second drilling blade in a plan view it is characterized in that it is located outside.

  Further, the ground improvement method according to the present invention is a ground improvement method using the ground improvement device described above, wherein the ground improvement device is installed on the ground to be improved, and includes a plurality of first rotation shafts and second rotation shafts. A step of rotating the first excavation blade and the second excavation blade to excavate the ground of the first excavation region; a step of excavating a second excavation region corresponding to a cross-sectional region with a side cutter; and the first excavation region and the second excavation region And a step of mixing the ground improvement material with the ground excavated in the excavation area and stirring.

  In the present invention, among the ground improvement regions surrounded by the common circumscribing line of the rotation trajectory between the adjacent first excavating blades, a cross-sectional region that remains without being excavated by the first excavating blade and the second excavating blade (second excavation blade). The area) can be scraped off by the side cutter, whereby the entire ground improvement area can be excavated and improved. That is, since the entire ground improvement area becomes an effective cross section as a ground improvement wall, it is possible to prevent a part of the excavation area from becoming an excessive excavation part that does not function as a ground improvement wall as in the past. Therefore, the outer diameter of the first excavation blade can be made smaller than that of the conventional excavation blade, and the amount of ground improvement material corresponding to the portion corresponding to the excessive excavation can be reduced. Costs can be reduced and the apparatus can be downsized.

  Further, since the side cutter only needs to be provided at a position along the common circumscribing line of the rotation trajectory of the adjacent first excavating blades, a configuration without a driving mechanism such as rotation or swinging may be used, and complicated driving means may be used. Since an unnecessary and simple configuration is sufficient, the cost can be reduced.

  Moreover, in this invention, since a ground improvement apparatus is made into a simple structure and can be reduced in size, it can be used as an attachment of working machines, such as a backhoe. Therefore, even in a narrow space, the ground improvement device can be introduced to form a ground improvement wall. In this case, by forming the outer periphery improvement portion so as to surround the ground under the existing structure, the horizontal movement of the ground under the structure surrounded by the outer periphery improvement portion is restricted, and fluctuations are suppressed. Therefore, the destruction of the ground can be prevented. Therefore, the vibration of the structure during an earthquake can be reduced and the structure can be prevented from being destroyed.

In the ground improvement device according to the present invention, it is preferable that the side cutter is provided in a region surrounded by a range obliquely upward with respect to the horizontal plane from the outer peripheral edge of the second excavating blade.
In this case, it becomes possible to arrange the side cutter in a region where looseness is generated surrounded by a range obliquely upward from the outer peripheral edge of the second excavating blade, and in that case, the loose ground It can be easily excavated by scraping off with a side cutter. And since the position of the height direction of a side cutter is located above a 1st excavation blade and a 2nd excavation blade, after passing a fixed time from the time of excavation by these 1st excavation blade and a 2nd excavation blade It is cut by the side cutter. For this reason, since the ground of the natural ground at the portion to be cut by the side cutter proceeds, cutting by the side cutter becomes easier.

Further, in the ground improvement device according to the present invention, the side cutter is formed with an inclined surface toward the vertical surface including the common circumscribed line gradually from the central portion to the outer peripheral portion in plan view on the inner surface side. Is preferred.
In this case, since the lower end of the side cutter has a sharp shape and the tip is on the common outer tangent, the ground can be scraped off cleanly along the common outer tangent. And since the front-end | tip of a side cutter tends to bite into a natural ground and cutting resistance becomes small, there exists an advantage that a smooth excavation can be performed.

In the ground improvement device according to the present invention, it is more preferable that the side cutter has a shape in which the lower end side is tapered in a plan view.
As a result, the tip of the side cutter easily bites into the ground and the cutting resistance is reduced, so that there is an advantage that smooth excavation can be performed.

Moreover, in the ground improvement apparatus which concerns on this invention, it is preferable that the connection shaft which connects a 1st rotating shaft and a 2nd rotating shaft to a horizontal direction each rotatably is provided, and the side cutter is supported by the connecting shaft.
In the present invention, since the connecting shaft is not rotated by the rotating shaft for rotating the excavating blade, the posture of the side cutter supported by the connecting shaft is stable, and the position of the excavating blade does not change. The ground improvement area can be excavated in a certain shape in the depth direction.

According to the ground improvement device and the ground improvement method using the ground improvement device of the present invention, the entire area excavated by the first excavation blade, the second excavation blade, and the side cutter is set as an effective cross section as a ground improvement wall, and the ground improvement is performed. Since the excessive excavation of the portion can be eliminated and the ground improvement material added to the excessive excavation portion can be eliminated as in the prior art, the cost can be reduced.
Further, since the side cutter has a simple bit-like structure that does not depend on driving means such as rotation and swinging, the cost can be reduced.

It is a front view which shows the structure of the ground improvement apparatus by embodiment of this invention. It is the AA arrow line view shown in FIG. 1, Comprising: It is the figure which looked at the ground improvement apparatus from the downward direction. It is an enlarged view which shows the structure of a side cutter, Comprising: (a) is a front view, (b) is a side view. (A) is a diagram showing a first excavation area excavated by the first excavation blade and the second excavation blade in the ground improvement area, and (b) is a second excavation area excavated by the side cutter in the ground improvement area. FIG. It is the side view which mounted | wore the working machine with the ground improvement apparatus. It is a figure for demonstrating the ground improvement method using the ground improvement apparatus shown in FIG. 1, Comprising: (a) is a side view, (b) is a top view of a ground improvement part. It is a figure for demonstrating the ground improvement method by a 1st modification, Comprising: (a) is a side view, (b) is a top view of a ground improvement part. It is a figure for demonstrating the ground improvement method by a 2nd modification, Comprising: (a) is a side view, (b) is a top view of a ground improvement part. It is a figure for demonstrating the ground improvement method by a 3rd modification, Comprising: (a) is a side view, (b) is a top view of a ground improvement part. It is a figure for demonstrating the ground improvement method by a 4th modification, Comprising: (a) is a side view, (b) is a top view of a ground improvement part. It is a horizontal sectional view of the ground improvement part by the conventional ground improvement apparatus.

  Hereinafter, a ground improvement device according to an embodiment of the present invention and a ground improvement method using the same will be described with reference to the drawings.

  As shown in FIG. 1, the ground improvement device 1 according to the present embodiment is a device for forming a ground improvement portion in a wall shape or a block shape, for example, immediately below the foundation of a building. Used as an attachment at the tip of the arm of the work machine 2 (see FIG. 5) such as a backhoe, and excavated by moving the ground in the vertical direction while rotating the excavating blades provided at the lower ends of the triaxial rods. Then, the ground improvement material is added to the excavated soil, mixed, and stirred to construct the ground improvement portion.

Here, as the ground improvement material added to the excavated soil, an appropriate agent such as a liquid material such as cement milk or a powdered material can be employed depending on the purpose of the ground improvement.
In the following description, “excavated soil” includes a mixture of the ground excavated by the ground improvement device 1 and the ground improvement material. Moreover, in the ground improvement apparatus 1 shown in FIG. 1, the length dimension in the left-right direction toward the paper surface is referred to as “width direction X”.

  The ground improvement device 1 rotates about a vertical axis, and is fixed to a plurality of first rotation shafts 11 (11A, 11B, 11C) provided in parallel to each other, and respectively fixed to the lower ends of the first rotation shafts 11, and rotates horizontally. The first excavating blades 12 (12A, 12B, 12C) and the first rotary shafts 11 adjacent to each other are arranged in parallel to the first rotary shaft 11, and the rotation of the first rotary shaft 11 is transmitted to rotate around the vertical axis. A second rotating shaft 13 (13A, 13B) that rotates in a horizontal direction, a second excavating blade 14 (14A, 14B) that is fixed to the lower end of the second rotating shaft 13 and rotates in the horizontal direction, and an upper portion of the second excavating blade 14 2 is located in a cross-sectional area (second excavation area M2 to be described later) that is not excavated by the first excavating blade 12 and the second excavating blade 14, and a common outer tangent of the rotation trajectory of the adjacent first excavating blades 12 (in FIG. 2) Side cutter 15 provided along the symbol T) , And a.

  Of the three first rotary shafts 11A, 11B, and 11C, the central first rotary shaft 11B has a length dimension that projects downward from the first rotary shafts 11A and 11C on both sides, and each upper end 11a is described later. The support frame 16 (see FIG. 5) is supported so as to be rotatable about an axis. And the front-end | tip blade 17 which makes the shape pointed toward the downward direction at the front-end | tip of each 1st rotating shaft 11 is provided.

The three first rotating shafts 11 and the two third rotating shafts 13 are parallel to each other and spaced apart from each other by connecting shafts 18 at a plurality of locations (four locations in FIG. 1) in the axial direction Y. It is supported. The second rotary shafts 13A and 13B have the same length, are shorter than the first rotary shaft 11, and the second excavating blade 14 provided at the lower end is positioned above the first excavating blade 12. Yes.
The connecting shaft 18 extends along the width direction X, supports the first rotating shaft 11 and the second rotating shaft 13 rotatably, and connects the rotating shafts 11 and 13 in the horizontal direction.

In each of the first excavating blades 12A, 12B, and 12C, a rod-shaped blade shaft 12a extends radially outward from the lower end of the first rotating shaft 11A, 11B, and 11C, and a plurality of cutting bits are provided on the peripheral surface of the blade shaft 12a. 12b is arranged, and rotates around the central axis together with the first rotating shaft 11. As shown in FIG. 2, the second excavation blades 14 </ b> A and 14 </ b> B excavate a cross section having a smaller diameter than the first excavation blade 12, and rotate around the central axis along with the second rotation shaft 13.
Then, the first excavation blade 12 and the second excavation blade 14 excavate the first excavation region M1 shown in FIG.

  Moreover, the 1st rotating shaft 11 is provided with the flow path over the whole axial direction inside, and the ground improvement material supplied to the upper end 11a distribute | circulates to a lower end. A spout 12d for injecting the ground improvement material is provided on the peripheral surface of the first excavation blade 12 in communication with an internal flow path, and the ground improvement material is supplied from the spout 12d to the first excavation blade. 12 and the second excavating blade 14 are rotated outward in the radial direction along with the rotation and mixed with the excavated soil.

  As shown in FIG. 1, the first rotating shaft 11 and the second rotating shaft 13 are provided with stirring blades 19 that rotate together with the rotating shafts 11 and 13 at predetermined positions in the axial direction of the rotating shafts 11 and 13, respectively. It has been. The stirring blades 19 each have a shape in which a plurality of blades extend radially outward, and a range between the first connecting shaft 18A provided at the lowermost portion and the second connecting shaft 18B provided second from the bottom. Is provided. And the stirring blade 19 provided in the 1st rotating shaft 11 and the stirring blade 19 provided in the 2nd rotating shaft 13 are arrange | positioned in the position shifted | deviated to the up-down direction so that it may not mutually interfere.

As shown in FIGS. 2 and 3 (a), 3 (b), the side cutters 15 are arranged on both sides of the bottom first connecting shaft 18A in the thickness direction Z of the ground excavator 1, and the first The one connecting shaft 18A is supported via a connecting member 20.
As shown in FIG. 4B, the side cutter 15 includes a ground improvement region M0 surrounded by a common circumscribing line T of the rotation trajectory excavated by the plurality of first excavation blades 12A to 12C, and the ground improvement region. It is located in the 2nd excavation area | region M2 between the 1st excavation area | region M1 (refer Fig.4 (a)) excavated by the 1st excavation blade 12 and the 2nd excavation blade 14 among M0.

  The side cutter 15 is formed with an inclined surface 15a (refer to FIG. 3 (b)) gradually toward the vertical surface including the common circumscribing line T as it goes from the central portion to the outer peripheral portion in plan view on the inner surface side. Furthermore, the lower end side is formed in a tapered shape. Further, the side cutter 15 is provided in a loose region R surrounded by a range from the outer peripheral edge 14a of the second excavating blade 14 to an obliquely upward 45 degrees (θ = 45 degrees in FIG. 3) with respect to the horizontal plane. .

  As shown in FIG. 6, the support frame 16 rotatably supports the upper end 11 a of the first rotary shaft 11 and the upper end 13 a of the second rotary shaft 13, and a pin or the like is attached to the tip 21 a of the arm 21 of the work machine 2. A drive motor (not shown) that is connected by a detachable connecting means and applies rotational power to the rotary shafts 11 and 12 is provided inside.

Next, the ground improvement method using the ground improvement apparatus 1 mentioned above is demonstrated.
As shown in FIG. 5, the ground improvement device 1 is used as an attachment of the work machine 2 such as a backhoe, and the support frame 16 is attached to the tip 21 a of the arm 21 of the work machine 2. Then, after the ground improvement device 1 is installed on the ground to be improved, the working machine 2 applies a downward force in the vertical direction to the ground improvement device 1 to take the excavation reaction force, and together with the first excavation blades 12A, 12B, 12C The second excavation blades 14A and 14B are rotated to excavate the ground in the first excavation area M1 shown in FIG. 4A, and further, the ground in the second excavation area M2 shown in FIG. Cut as if dropping.
By performing the ground improvement in this way, as shown in FIG. 4 (b), the first excavation area M1 is excavated, and the second excavation area M2 is scraped off by the side cutter 15 to form the ground improvement area M0. Will be formed.

  In addition, the ground improvement material is injected toward the ground from the injection port 11b of the first rotating shaft 11 to the excavated soil excavated in the first excavating region M1 and the second excavating region M2, and the first rotating shaft 11 and the second rotating shaft are rotated. The excavated soil is uniformly and effectively mixed and stirred by a plurality of stirring blades 19 provided on the shaft 13.

Next, the operation of the ground improvement device 1 described above will be specifically described based on the drawings.
In the ground improvement device 1, the first excavation blade 12 and the second excavation blade 14 are not excavated in the ground improvement region M0 surrounded by the common circumscribed line T of the rotation trajectory between the adjacent first excavation blades 12. The remaining cross-sectional area (second excavation area M2) can be scraped off by the side cutter 15, whereby the entire ground improvement area M0 can be excavated and improved.
That is, since the entire ground improvement region M0 has an effective cross section as a ground improvement wall, it is possible to prevent a part of the excavation region from becoming an excessive excavation portion that does not function as a ground improvement wall as in the past. Accordingly, the outer diameter of the first excavation blade 12 can be made smaller than that of the conventional excavation blade, and the amount of ground improvement material corresponding to the portion corresponding to the excessive excavation can be reduced. The construction cost can be reduced and the apparatus can be downsized.

  Further, since the side cutter 15 only needs to be provided at a position along the inner side of the common circumscribing line T of the rotation trajectory of the adjacent first excavating blades 12, it may be configured without a driving mechanism such as rotation or swinging, Since a complicated drive means is not required and a simple configuration is sufficient, the cost can be reduced.

  Further, since the cutting area of the side cutter 15 is a loose area R surrounded by a range obliquely upward 45 degrees from the outer peripheral edge 14a of the second excavating blade 14 with respect to the horizontal plane, the loose ground is removed by the side cutter 15. It can be easily excavated by scraping off.

Further, the side cutter has a shape having an inclined surface 15a with a sharp lower end, and its tip 15b is on the common circumscribing line T. Therefore, the ground can be scraped cleanly along the common circumscribing line T. And since the front-end | tip 15b of the side cutter 15 bites into a natural ground easily and cutting resistance becomes small, there exists an advantage that a smooth excavation can be performed.
Since the side cutter 15 has a shape in which the lower end side is tapered in a plan view, the tip 15b is easy to bite into the natural ground and the cutting resistance is reduced, so that there is an advantage that smooth excavation can be performed.

  Further, since the side cutter 15 is supported by the connecting shaft 18A and the connecting shaft 18A is not rotated by the rotating shafts 11 and 13 for rotating the excavating blades 12 and 14, the side cutter supported by the connecting shaft 18A. Since the posture of 15 is stable and the positions of the excavating blades 12 and 14 do not change, the ground improvement region M0 can be excavated in a constant shape in the depth direction.

Next, the earthquake-proof method using the ground improvement apparatus 1 mentioned above is demonstrated based on drawing.
As shown in FIGS. 6A and 6B, the seismic construction method according to the present embodiment is based on the ground improvement around the structure 3 using the ground improvement device 1 described above.
That is, the ground improvement device 1 shown in FIG. 1 is introduced into the ground to be improved in the region surrounding the ground below the structure 3, and the first excavation blade 12 and the second excavation blade 14 perform the first operation shown in FIG. While excavating 1 excavation area | region M1, the 2nd excavation area | region M2 shown in FIG.4 (b) is excavated by the side cutter 15, and a 1st ground improvement body is made by mixing and mixing a ground improvement material in the excavated ground. 4A is formed.

  Since the ground improvement device 1 according to the present embodiment has a simple structure as described above and can be downsized, it can be used as an attachment for the work machine 2 such as a backhoe (see FIG. 5). . Therefore, even in a narrow space, the ground improvement device 1 can be introduced to form the first ground improvement body 4A. In the first ground improvement body 4A shown in FIG. 6, an outer peripheral improvement portion 41 is formed so as to surround the ground under the existing structure 3, and the ground g under the structure 3 surrounded by the outer peripheral improvement portion 41 is formed. Since the movement in the horizontal direction is restricted and the fluctuation is suppressed, the destruction of the ground can be prevented. Therefore, the vibration of the structure 3 during an earthquake can be reduced, and the structure 3 can be prevented from being broken.

As described above, in the ground improvement device according to the present embodiment and the ground improvement method using the ground improvement device, the entire area excavated by the first excavation blade 12, the second excavation blade 14, and the side cutter 15 is used as the ground improvement wall. Therefore, it is possible to eliminate the excessive excavation of the ground improvement portion, and it is possible to eliminate the ground improvement material added to the excessive excavation portion as in the prior art, so that the cost can be reduced.
Further, since the side cutter 15 has a simple bit-like structure that does not depend on driving means such as rotation and swinging, the cost can be reduced.

  Next, modifications of the present embodiment will be described with reference to the accompanying drawings. However, the same or similar members and parts as those of the above-described embodiment are denoted by the same reference numerals, and the description thereof is omitted. A configuration different from the above will be described.

  The first to fourth modifications shown in FIGS. 7 to 10 are other examples of the ground improvement method according to the above-described embodiment, and the ground improvement device 1 (see FIG. 1) is used in the same manner as the above-described embodiment. It is constructing.

  The second ground improvement body 4B according to the first modification shown in FIGS. 7A and 7B is provided by the ground improvement device 1 (see FIG. 1) over the entire inner surface of the outer peripheral improvement portion 41 surrounded by a square shape in plan view. An improved surface improvement portion 42 is formed. Also in this case, the outer peripheral improvement portion 41 can regulate the fluctuation of the ground g on the lower surface side of the surface improvement portion 42.

Next, the 3rd ground improvement object 4C by the 2nd modification shown in Drawing 8 (a) and (b) is a building foundation construction method for structure 3, and the ground improvement device like the above-mentioned embodiment. 1 (see FIG. 1).
The ground improvement unit 10G is a seismic improvement method for improving the ground directly supporting the structure 3 such as a house. The ground improvement device 1 (see FIG. 1) is inserted directly under the structure 3 to excavate a predetermined area. At the same time, the outer periphery improving portion 43 is formed by mixing the ground improvement material with the excavated ground and stirring. This outer periphery improvement part 43 is arrange | positioned along the outer peripheral part of the structure 3 by planar view, The fluctuation | variation of the ground g just under the structure 3 is controlled. In this case, it is also possible to provide a fabric foundation (not shown) at the upper end of the outer periphery improving portion 43 and construct the structure 3 on the fabric foundation via a foundation beam.

  In the fourth ground improvement body 4D according to the third modification shown in FIGS. 9A and 9B, a solid foundation 44 is provided at the upper end of the outer circumference improvement section 43, and the outer circumference support section 43 is disposed above the solid foundation 44 via the solid foundation 44. The structure 3 is directly supported.

  The fifth ground improvement body 4E according to the fourth modification shown in FIGS. 10 (a) and 10 (b) is shaped like a rice field in plan view so as to partition the section when it is constructed before constructing the structure. The section improvement unit 45 is formed by the ground improvement device 1 (see FIG. 1).

As mentioned above, although the embodiment of the ground improvement apparatus by this invention and the ground improvement method using the same was described, this invention is not limited to said embodiment, In the range which does not deviate from the meaning, it is appropriate. It can be changed.
For example, in this embodiment, the side cutter 15 is connected to and supported by the first connecting shaft 18A via the connecting member 20, but is not limited to being supported at this position.
Further, the length dimension in the width direction X of the side cutter 15 can be arbitrarily set as long as it is within the range of the second excavation region M2.
Further, in the present embodiment, the loose region in which the side cutter 15 is surrounded by the range above the second excavating blade 14 and at an angle of 45 degrees obliquely upward from the outer peripheral edge 14a of the second excavating blade 14 with respect to the horizontal plane. Although it is provided at R, it is not limited to being provided at this position. For example, the side cutter 15 can be arranged at the same height level as the second excavating blade 14. In short, it is only necessary that the side cutter 15 is provided at a position along the common outer tangent line T of the rotation trajectory of the first excavating blades 12 adjacent to each other in plan view.

Further, the configurations of the outer diameter size, arrangement, shape, quantity, and the like of the first excavating blade 12 and the second excavating blade 14 can be arbitrarily set. Furthermore, the number of first rotating shafts 11 and the second rotating shaft 13, length dimensions, and the like can be arbitrarily set in accordance with the specification conditions of the apparatus. For example, in the present embodiment, the first excavation blade 12B located at the center in the width direction protrudes downward from the first excavation blades 12A and 12C on both sides, but not limited to this, the three excavation blades 12A to 12C. Both may be arranged at the same height level.
Furthermore, the size, arrangement, shape, quantity, and the like of the stirring blade 19 can be appropriately set according to the geology of the improvement target ground, the excavation speed, and the like.
Further, the installation position and the installation quantity of the connecting shaft 18 in the vertical direction are not limited to the present embodiment, and can be arbitrarily set.

Moreover, although the ground improvement apparatus 1 by this Embodiment is used as an attachment attached to work machines 2, such as a backhoe, it is not restrict | limited to such a usage form, For example, on a special stand It can also be installed and used.
Furthermore, the position and depth of the ground improvement parts 4A to 4E by the seismic method, the distance between the structure 3 and the outer periphery improvement part 41, the thickness dimension of the surface improvement part 42, etc. are not particularly limited.

DESCRIPTION OF SYMBOLS 1 Ground improvement apparatus 2 Working machine 3 Structure 4A-4E Ground improvement body 11, 11A-11C 1st rotating shaft 12, 12A-12C 1st excavation blade 13, 13A, 13B 2nd rotating shaft 14, 14A, 14B 2nd Excavation blade 15 Side cutter 16 Support frame 18 Connecting shaft 19 Stirring blade 41, 43 Outer periphery improvement portion 42 Surface improvement portion 44 Solid foundation M0 Ground improvement region M1 First excavation region M2 Second excavation region T Common external tangent

Claims (6)

A ground improvement device that moves the ground and improves the ground,
A plurality of first rotating shafts rotating around a vertical axis and provided in parallel with each other;
A first excavating blade fixed to the lower end of the first rotating shaft and rotating horizontally;
A second rotating shaft that is arranged in parallel with the first rotating shaft in the middle between the adjacent first rotating shafts, and that rotates around the vertical axis by transmitting the rotation of the first rotating shaft;
A second excavating blade fixed to the lower end of the second rotating shaft and rotating in the horizontal direction and having a smaller diameter than the first excavating blade ;
A side cutter that is located in a cross-sectional area that is not excavated by the first excavating blade and the second excavating blade, and that is provided along a common circumscribing line of a rotation trajectory between adjacent first excavating blades;
Equipped with a,
The side cutters are disposed on both sides of the second rotating shaft in the thickness direction of the ground improvement device, and are located outside the second excavating blade in a plan view as viewed from below. Features ground improvement device.   2. The ground improvement device according to claim 1, wherein the side cutter is provided in a region surrounded by a range obliquely upward with respect to a horizontal plane from an outer peripheral edge of the second excavation blade.   3. The side cutter according to claim 1, wherein an inclined surface is formed on the inner surface side so as to gradually move toward a vertical surface including the common circumscribed line from the central portion to the outer peripheral portion in plan view. The ground improvement device described.   The ground improvement device according to any one of claims 1 to 3, wherein the side cutter has a shape in which a lower end side thereof is tapered in a plan view. A connecting shaft is provided for horizontally connecting the first rotating shaft and the second rotating shaft in a rotatable manner.
The ground improvement device according to any one of claims 1 to 4, wherein the side cutter is supported by the connecting shaft. A ground improvement method using the ground improvement device according to any one of claims 1 to 5,
The step of installing the ground improvement device on the ground to be improved and excavating the ground in the first excavation region by rotating the first excavation blade and the second excavation blade together with the first rotation shaft and the second rotation shaft. When,
Excavating a second excavation area corresponding to the cross-sectional area with the side cutter;
Mixing and stirring a ground improvement material in the ground excavated in the first excavation area and the second excavation area;
The ground improvement method using the ground improvement apparatus characterized by having.

Images