Ground improvement device and ground improvement method

Abstract

To easily change an agitation device existing in a ground improvement device into another agitation device or a drilling device in the middle of the construction of a ground improvement method.SOLUTION: In a ground improvement device (1) and a ground improvement method, an agitation device (15) is interlocked with and connected to a rotary shaft (14) where a hollow outer shaft (17) is provided outside an inner shaft (16) in a double-pipe manner, and sediment and a ground improvement material are agitated and mixed in a ground (2); thereby, the improvement of the ground (2) is performed. The rotary shaft (14) and the agitation device (15) are interlocked and connected via a connection adapter (47), and the existing agitation device (15) can be replaced with another agitation device (15') or a drilling device (70) via the connection adapter (47).SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a ground improvement device and a ground improvement method that improves the ground by stirring and mixing soil and soil improvement materials in the ground using a rotating shaft that has a hollow outer shaft attached to the outside of an inner shaft in a double-tube configuration and an agitator connected to it. [Background technology]

[0002] Conventionally, ground improvement has been carried out for the purpose of strengthening weak ground or purifying contaminated ground.

[0003] The ground improvement device used in this ground improvement is configured so that a rotating shaft has a hollow outer shaft arranged in a double-tube shape outside the inner shaft, to which is connected a stirring device having an excavation body connected to the inner shaft, an inner stirring blade, and an outer stirring blade connected to the outer shaft.

[0004] In the ground improvement method using a ground improvement device, an excavation device is used to excavate the ground, and a ground improvement material (such as a solidification agent or a purification agent) is discharged into the excavated ground. The ground improvement material and the soil and sand are then stirred and mixed in the ground using a stirring device, thereby creating an improved body in the ground (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2021-161843 Summary of the Invention [Problem to be solved by the invention]

[0006] When the above-mentioned ground improvement method is used to form the foundation of a structure such as a building, the shape of the foundation is determined according to the axial force acting on each column of the structure, and improvement bodies are constructed in the ground according to this foundation shape. If improvement bodies of multiple diameters are used, it is possible to place improvement bodies with minimal waste according to each foundation shape, but if improvement bodies of one diameter are used, the cost required for construction will increase.

[0007] Therefore, in conventional ground improvement methods, ground improvement is carried out using a mixer with a specified diameter attached to a double-tube rotating shaft consisting of an inner shaft and an outer shaft, and then the mixer already installed on the rotating shaft is replaced with another mixer with a different diameter, and ground improvement is carried out using the replaced mixer.In this way, the outer diameter of the outer mixing blades of the mixer is changed, and the improvement range within the ground (the range in which the ground improvement material and soil are mixed) is changed.

[0008] In particular, in the case of a ground improvement device having a single-pipe rotating shaft, the single-pipe rotating shaft can be replaced with an agitator by simply detaching and attaching a connecting pin, but in the case of a ground improvement device having the above-mentioned double-pipe rotating shaft, both the inner shaft and the outer shaft must be attached and detached at the same time, making the work of replacing the agitator complicated and requiring a great deal of time and effort.

[0009] Therefore, in the present invention, it is possible to easily change the mixing device already installed in the ground improvement device to another mixing device or excavation device during the construction of a ground improvement method using a ground improvement device with a double-pipe rotating shaft. [Means for solving the problem]

[0010] In the present invention according to claim 1, a ground improvement device is provided which improves the ground by stirring and mixing soil and ground improvement materials in the ground by connecting an agitator to a rotating shaft having a hollow outer shaft in a double-tube shape outside the inner shaft, and the rotating shaft and the agitator are connected to each other via a connecting adapter, and an existing agitator can be replaced with another agitator or excavation device via the connecting adapter.

[0011] Furthermore, in the present invention according to claim 2, in the present invention according to claim 1, the connecting adapter is provided between the seal rod and the stirring device to prevent soil and ground improvement material from flowing in between the inner and outer shafts of the rotating shaft.

[0012] Furthermore, in the present invention according to claim 3, in the present invention according to claim 1 or claim 2, the connecting adapter has an inner shaft connecting body that detachably connects the inner shaft of the rotating shaft and the inner stirring blade of the stirring device, an outer shaft connecting body that is hollow outside the inner shaft connecting body and detachably connects to the outer shaft of the rotating shaft, and an outer stirring blade connecting body that is hollow outside the inner shaft connecting body and detachably connects to the outer stirring blade of the stirring device, and the outer shaft connecting body and the outer stirring blade connecting body can be detachably connected.

[0013] In addition, in the present invention according to claim 4, in a ground improvement method in which an agitator is linked to a rotating shaft having a hollow outer shaft attached to the outside of an inner shaft in a double-tube shape, and soil and ground improvement materials are mixed and stirred in the ground to improve the ground, the rotating shaft and the agitator are linked via a connecting adapter, and the existing agitator is replaced with another agitator or excavator via the connecting adapter.

[0014] In the present invention according to claim 5, in the present invention according to claim 4, the connecting adapter has an inner shaft connector that detachably connects the inner shaft of the rotating shaft and the inner stirring blade of the stirring device, an outer shaft connector that is hollow outside the inner shaft connector and is connected to the outer shaft of the rotating shaft, and an outer stirring blade connector that is hollow outside the inner shaft connector and is connected to the outer stirring blade of the stirring device, making it possible to detachably connect the outer shaft connector and the outer stirring blade connector, and by detaching the inner shaft connector of the connecting adapter from the inner stirring blade of an existing stirring device, At the same time, the outer shaft connector of the connecting adapter is detached from the outer agitator blade connector that is interlocked and connected to the existing agitator, thereby removing the existing agitator from the rotating shaft, and then the inner shaft connector of the connecting adapter is interlocked and connected to another agitator or excavation device, and the outer shaft connector of the connecting adapter is connected to the outer agitator blade connector that is interlocked and connected to the other agitator or excavation device, thereby attaching the other agitator or excavation device to the rotating shaft, and replacing the existing agitator with the other agitator or excavation device via the connecting adapter. [Effects of the Invention]

[0015] The present invention provides the following effects.

[0016] In other words, in this invention, in a ground improvement device that improves the ground by stirring and mixing soil and ground improvement material within the ground, an agitator is connected to a rotating shaft that has a hollow outer shaft attached to the outside of the inner shaft in a double-tube shape, and the rotating shaft and the agitator are connected to each other via a connecting adapter, so that the agitator already installed in the ground improvement device can be replaced with another agitator or excavation device via the connecting adapter, and therefore the agitator already installed in the ground improvement device can be easily changed to another agitator or excavation device by using the connecting adapter.

[0017] In particular, if a connecting adapter is provided between the seal rod and the agitator to prevent soil and ground improvement materials from flowing in between the inner and outer shafts of the rotating shaft, it is possible to eliminate the long-term work of removing soil and ground improvement materials that have adhered to the seal rod, etc. when replacing the agitator, thereby reducing the effort and time required to replace the agitator.

[0018] Furthermore, when a connecting adapter is used that has an inner shaft connecting body that detachably connects the inner shaft of the rotating shaft and the inner stirring blade of the stirring device, an outer shaft connecting body that is hollow outside the inner shaft connecting body and is operatively connected to the outer shaft of the rotating shaft, and an outer stirring blade connecting body that is hollow outside the inner shaft connecting body and is operatively connected to the outer stirring blade of the stirring device, and that allows the outer shaft connecting body and the outer stirring blade connecting body to be detachably connected, the rotating shaft and the stirring device can be easily attached and removed, thereby further reducing the effort and time required to replace the stirring device.

[0019] Furthermore, in the present invention, in a ground improvement method in which an agitator is linked to a rotating shaft having a hollow outer shaft attached to the outside of an inner shaft in a double-tube configuration, and the soil and ground improvement material are stirred and mixed within the ground to improve the ground, the rotating shaft and the agitator are linked together via a connecting adapter, and the existing agitator can be replaced with another agitator or excavation device via the connecting adapter, so that the agitator already installed in the ground improvement device can be easily changed to another agitator or excavation device by using the connecting adapter.

[0020] In particular, the connecting adapter has an inner shaft connector that detachably connects the inner shaft of the rotating shaft and the inner stirring blade of the stirring device, an outer shaft connector that is hollowly provided outside the inner shaft connector and is operatively connected to the outer shaft of the rotating shaft, and an outer stirring blade connector that is hollowly provided outside the inner shaft connector and is operatively connected to the outer stirring blade of the stirring device, and the outer shaft connector and the outer stirring blade connector can be detachably connected, and the inner shaft connector of the connecting adapter can be detached from the inner stirring blade of the existing stirring device, and the outer shaft connector of the connecting adapter can be detached from the outer stirring blade connector operatively connected to the existing stirring device. By disconnecting the connecting adapter, the existing agitator can be removed from the rotating shaft, and then the inner shaft connector of the connecting adapter is connected to another agitator or drilling device, and the outer shaft connector of the connecting adapter is connected to the outer agitator blade connector which is connected to the other agitator or drilling device.By attaching another agitator or drilling device to the rotating shaft, if it is decided to replace the existing agitator with another agitator or drilling device via the connecting adapter, the agitator can be easily attached and detached from the rotating shaft, thereby further reducing the effort and time required to replace the agitator. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. [Figure 2] FIG. [Figure 3] Same plan view. [Figure 4] FIG. [Figure 5] (a) is a side view, and (b) is a cross-sectional side view. [Figure 6] FIG. 10 is an explanatory diagram showing the attachment operation of the coupling adapter. [Figure 7] FIG. 10 is an explanatory diagram showing the process of replacing an existing agitation device with another agitation device. [Figure 8] FIG. 10 is an explanatory diagram showing the work of replacing the existing mixing device with another excavation device. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, specific configurations of the ground improvement device and the ground improvement method according to the present invention will be described with reference to the drawings.

[0023] As shown in Figures 1 to 3, the ground improvement device 1 is a device for excavating the ground 2 and stirring and mixing the excavated soil and sand with a ground improvement material (solidification material) to improve the strength and properties of the ground 2. This ground improvement device 1 has a support 4 erected at the front end of a heavy machine 3, and a ground improvement mechanism 5 attached to this support 4 so that it can be raised and lowered. A ground improvement material supply mechanism 6 is connected to this ground improvement mechanism 5 via a swivel joint 7. The ground improvement material supply mechanism 6 is configured to connect a ground improvement material storage tank 8 and a water tank 9 to a ground improvement material mixing plant 10, and to connect a ground improvement material discharge pump 11 to the ground improvement material mixing plant 10, so that the ground improvement material is supplied to the ground improvement mechanism 5.

[0024] The ground improvement mechanism 5 has a lifting support 12 attached to the front side of the support 4 so that it can be raised and lowered freely, a driver 13 attached to this lifting support 12, the base end (upper end) of a rotating shaft 14 extending in the vertical direction attached to the driver 13, and an agitator 15 connected in tandem to the tip end (lower end) of the rotating shaft 14.

[0025] The driving body 13 has an inner shaft 16 and an outer shaft 17 that constitute the rotary shaft 14, and a driving motor 18 connected to the inner shaft 16 and the outer shaft 17 via a reversing transmission 19.

[0026] The rotating shaft 14 is composed of an inner shaft 16 and an outer shaft 17, with their central rotation axes arranged coaxially. The outer shaft 17, also a hollow cylindrical shape extending vertically, is provided on the outside of the inner shaft 16, which is a hollow cylindrical shape extending vertically, in a double-tube configuration. The tip of the inner shaft 16 of the rotating shaft 14 protrudes downward further than the tip of the outer shaft 17. When a drive motor 18 is driven, the inner shaft 16 and the outer shaft 17 rotate in relatively opposite directions due to the action of a reversing transmission 19. The hollow part of the inner shaft 16 is connected to a ground improvement material supply mechanism 6, and serves as a flow path for discharging the ground improvement material into the ground 2.

[0027] Agitator 15 is interlocked and connected to the tip (lower end) of rotating shaft 14 via a seal rod 20 for preventing soil and soil improvement material from flowing in between inner shaft 16 and outer shaft 17 of rotating shaft 14. This agitator 15 is composed of agitator blade body 21 for agitating and mixing soil and soil improvement material, and an excavator body 22 for excavating ground 2.

[0028] The seal rod 20 is configured such that the outer side of the inner shaft 16, which protrudes from the lower end of the outer shaft 17, is covered at a distance by a pair of front and rear exterior bodies 23, 24 attached to the lower end of the outer shaft 17. A hollow space between the inner shaft 16 and the exterior bodies 23, 24 is provided with an inflow prevention body 25 for preventing the inflow of soil and soil improvement materials. The inflow prevention body 25 is formed by sandwiching grease-impregnated nonwoven fabric between multiple ring-shaped packings spaced apart vertically. The exterior bodies 23, 24 connected to the outer shaft 17 of the seal rod 20 rotate in the opposite direction relative to the inner shaft 16. At this time, the inflow prevention body 25 of the seal rod 20 functions as both a bearing and a seal.

[0029] The agitator blade body 21 has an inner blade shaft 26 interlocked with the inner shaft 16 of the rotating shaft 14, and an outer blade shaft 27 interlocked with the outer shaft 17 of the rotating shaft 14, with the central rotation axis arranged coaxially, and the hollow cylindrical outer blade shaft 27 extending vertically is provided outside the hollow cylindrical inner blade shaft 26 extending vertically in a double-tube shape. The hollow part of the inner blade shaft 26 is connected to the ground improvement material supply mechanism 6 via the inner shaft 16, and a discharge port for the ground improvement material is formed at the tip (lower end) of the inner blade shaft 26, etc., which serves as a flow path for discharging the ground improvement material into the ground 2.

[0030] The agitator blade body 21 also has an innermost agitator blade 28 that is arranged on the innermost side, an inner agitator blade 29 that is arranged on the outer periphery of that, and an outer agitator blade 30 that is arranged further on the outer periphery of that (outermost side).

[0031] The innermost agitating blade 28 has two flat innermost agitating blade pieces 31 attached to the outer peripheral surface of the tip of the outer blade shaft 27, facing radially outward at an interval of 180 degrees in the circumferential direction.

[0032] The inner agitator blade 29 has two inner agitator blade pieces 32 attached to the tip of the inner blade shaft 26 in a radial pattern facing outward at 180-degree intervals in the circumferential direction. Each inner agitator blade piece 32 is formed into a roughly U-shape in side view with the middle part bulging outward, consisting of an inner agitator blade upper piece 33 extending downward at an angle, an inner agitator blade middle piece 34 extending vertically downward, and an inner agitator blade lower piece 35 extending upward at an angle. The inner agitator blade lower piece 35 of each inner agitator blade piece 32 is attached to the tip of the inner blade shaft 26, and the inner agitator blade upper piece 33 is attached to an annular body 36, which is loosely fitted around the outer peripheral surface of the outer blade shaft 27 so as to be freely rotatable. Each inner agitating blade piece 32 has an agitating piece 37 attached to the outside of the inner agitating blade mid-portion piece 34 , and a connecting piece 38 attached between the inner agitating blade mid-portion piece 34 and the inner blade shaft 26 .

[0033] The outer agitator blade 30 has three outer agitator blade pieces 39 attached to the tip of the outer blade shaft 27 in a radial pattern facing outward at 120-degree intervals in the circumferential direction. Each outer agitator blade piece 39 is formed into a roughly U-shape in side view with the middle part bulging outward, consisting of an outer agitator blade upper piece 40 extending downward at an angle, an outer agitator blade middle piece 41 extending vertically downward, and an outer agitator blade lower piece 42 extending upward at an angle. The outer agitator blade upper piece 40 of each outer agitator blade piece 39 is attached to the base end of the outer blade shaft 27, and the outer agitator blade lower piece 42 is attached to an annular body 43, which is loosely fitted around the outer peripheral surface of the inner blade shaft 26 so as to be freely rotatable. Each outer agitating blade piece 39 has two agitating blades 44 attached inside the outer agitating blade mid-section piece 41, one above the other, sandwiching an agitating blade 37 attached outside the inner agitating blade mid-section piece 34 therebetween.

[0034] In the agitator blade body 21, the inner blade shaft 26 rotates as the inner shaft 16 of the rotating shaft 14 rotates, and the outer blade shaft 27 rotates in the opposite direction relative to the inner blade shaft 26 as the outer shaft 17 of the rotating shaft 14 rotates, and the inner agitator blade 29 rotates as the inner blade shaft 26 rotates, and the innermost agitator blade 28 and the outer agitator blade 30 rotate in the opposite direction relative to the inner agitator blade 29 as the outer blade shaft 27 rotates, and these innermost agitator blade 28, inner agitator blade 29 and outer agitator blade 30 agitate and mix the soil and ground improvement material inside the ground 2.

[0035] The excavating body 22 has two flat excavating wings 45 attached radially outward at an interval of 180 degrees in the circumferential direction to the outer peripheral surface of the tip of the inner blade shaft 26, and a plurality of excavating bits 46 detachably attached at intervals on the left and right to the lower part of each excavating wing 45. In the excavating body 22, the excavating wings 45, 45 rotate as the inner blade shaft 26 (inner shaft 16) rotates, and the excavating bits 46 excavate the ground 2.

[0036] In the present invention, in the above-mentioned ground improvement device 1, the agitator 15 is interlockingly connected to the tip of the rotating shaft 14 via a seal rod 20, and the agitator 15 is detachably connected to the rotating shaft 14 and the seal rod 20 via a connecting adapter 47.

[0037] 4 and 5 , the connecting adapter 47 is composed of an inner shaft connector 48 that detachably connects the inner shaft 16 of the rotating shaft 14 and the inner agitator blade 29 of the agitator 15, an outer shaft connector 49 that is hollow outside the inner shaft connector 48 and operatively connected to the outer shaft 17 of the rotating shaft 14, and an outer agitator blade connector 50 that is hollow outside the inner shaft connector 48 and operatively connected to the outer agitator blade 30 of the agitator 15, allowing the outer shaft connector 49 and the outer agitator blade connector 50 to be detachably connected. Note that the inner shaft connector 48 only needs to be able to operatively connect the inner shaft 16 and the inner agitator blade 29, and is not limited to being directly connected to the inner shaft 16 or the inner agitator blade 29, but may be indirectly connected via other members, etc. Furthermore, the outer shaft connector 49 only needs to be operatively connected to the outer shaft 17, and is not limited to being directly connected to the outer shaft 17, but may be indirectly connected via other members, etc. Furthermore, the outer agitator blade connector 50 only needs to be interlocked and connected to the outer agitator blade 30, and is not limited to being directly connected to the outer agitator blade 30; it may be indirectly connected via other members, etc. Here, the inner shaft 16 is directly connected to the base end (upper end) of the inner shaft connector 48, and the inner agitator blade 29 is indirectly connected to the tip end (lower end) of the inner shaft connector 48 via the inner blade shaft 26 of the agitator 15. The base end (upper end) of the outer shaft connector 49 is indirectly connected to the outer shaft 17 via the exterior bodies 23, 24 of the seal rod 20, and the base end (lower end) of the outer agitator blade connector 50 is indirectly connected to the outer agitator blade 30 via the outer blade shaft 27 of the agitator 15.

[0038] The inner shaft connecting body 48 has a hollow cylindrical shape extending vertically, and has an insertion recess 51 formed at its base end (upper end) for inserting the tip end (lower end) of the inner shaft 16, and has insertion holes 52 formed at intervals in the vertical and horizontal directions that penetrate horizontally from the outer periphery through the insertion recess 51, and also has an insertion protrusion 53 formed at its tip end (lower end) for insertion into the hollow part of the inner blade shaft 26.

[0039] This inner shaft connector 48 is detachably connected at its base end (upper end) to the inner shaft 16 by a connecting pin 54 inserted through an insertion hole 52, and at its tip end (lower end) to the inner blade shaft 26 by a connecting pin 56 inserted through insertion holes 55 formed at the base end (upper end) of the outer blade shaft 27 at intervals in the vertical and horizontal directions. Note that insertion grooves 64, 65 that penetrate horizontally on the outer periphery are formed at intervals in the vertical and horizontal directions in the inner shaft 16 and the insertion protrusion 53.

[0040] The outer shaft connecting body 49 has a hollow cylindrical shape that extends vertically, and has a flange 57 formed at its base end (upper end) for detachably connecting the outer casings 23, 24 (which may be the outer shaft 17) of the seal rod 20, and a body 58 formed at the bottom of the flange 57 has insertion holes 59 that penetrate horizontally from the outer periphery and are spaced apart vertically and horizontally.

[0041] This outer shaft connector 49 is connected to the exterior bodies 23, 24 (or the outer shaft 17) of the seal rod 20 using connectors such as bolts and nuts at a flange 57 at the base end (upper end).

[0042] The outer agitator blade connecting body 50 has a hollow cylindrical shape extending vertically, and has a flange 60 formed at its base end (lower end) for detachably connecting the outer blade shaft 27, and has insertion grooves 62 formed at intervals vertically and horizontally that penetrate horizontally through the outer periphery of the body 61 formed at the top of the flange 60.

[0043] The outer diameter of the body 61 of the outer agitating blade connector 50 is approximately the same as the inner diameter of the body 58 of the outer shaft connector 49, so that the body 61 of the outer agitating blade connector 50 can be fitted inside the body 58 of the outer shaft connector 49. Furthermore, when the outer agitating blade connector 50 is fitted into the outer shaft connector 49, an insertion hole 59 formed in the outer shaft connector 49 and an insertion groove 62 formed in the outer agitating blade connector 50 match, and the outer shaft connector 49 and the outer agitating blade connector 50 are detachably connected by a connecting pin 63 inserted through the insertion hole 59.

[0044] The ground improvement device 1 is configured as described above, and in the ground improvement method, it is moved to a predetermined position in the ground 2, the ground improvement mechanism 5 is lowered, and the excavation body 22 of the mixing device 15 excavates the ground 2 to a predetermined depth, and then the ground improvement material is discharged from the ground improvement material supply mechanism 6 into the ground 2, and the mixing blade body 21 of the mixing device 15 mixes and stirs the ground improvement material and the excavated soil and sand while the ground improvement mechanism 5 is raised, and improvement piles are formed inside the ground 2.

[0045] To attach the connecting adapter 47 to this ground improvement device 1, as shown in Figure 6(a), the inner shaft connecting body 48 is placed on top of the ground 2, the rotating shaft 14 and the seal rod 20 of the ground improvement device 1 are lowered from directly above the inner shaft connecting body 48, the tip of the inner shaft 16 is inserted into the insertion recess 51 of the inner shaft connecting body 48, and the connecting pin 54 is inserted through the insertion hole 52 to interlock and connect the inner shaft 16 and the inner shaft connecting body 48.

[0046] Next, as shown in FIG. 6(b), the outer shaft coupling body 49 is placed on top of the ground 2 using a support 66, the rotating shaft 14 with the inner shaft coupling body 48 coupled to the inner shaft 16, and the seal rod 20 are lowered from directly above the outer shaft coupling body 49, the inner shaft coupling body 48 is inserted into the hollow part of the outer shaft coupling body 49, and the flange 57 of the outer shaft coupling body 49 and the seal rod 20 are coupled with a coupling tool, thereby interlocking and coupling the outer shaft 17 and the outer shaft coupling body 49.

[0047] Next, as shown in Figure 6(c), the agitator 15 with the excavation body 22 removed is placed on top of the ground 2 using a hollow support 67, and the outer blade shaft 27 of the agitator 15 is connected to the flange 60 of the outer agitator blade connector 50 with a connector, thereby connecting the agitator 15 and the outer agitator blade connector 50 in an interlocking manner.After that, the rotating shaft 14 and seal rod 20, which are connected to the inner shaft connector 48 and the outer shaft connector 49, are lowered from directly above the agitator 15 and the outer agitator blade connector 50, and the inner shaft connector 48 is inserted into the hollow part of the outer agitator blade connector 50, and the outer agitator blade connector 50 is fitted into the hollow part of the outer shaft connector 49.A connecting pin 63 is inserted through the insertion hole 59 to connect the outer shaft connector 49 and the outer agitator blade connector 50.

[0048] Next, as shown in FIG. 6(d), the connecting pin 56 is inserted through the insertion hole 55 to interlock and connect the inner shaft connecting body 48 and the agitator 15.

[0049] Next, as shown in Figure 6(e), the excavation body 22 is attached to the tip (lower end) of the agitator 15. This makes it possible to attach the agitator 15 to the ground improvement device 1 via the connection adapter 47.

[0050] In addition, to replace the agitator 15 (existing agitator 15) attached to the ground improvement device 1 via the connecting adapter 47 with another agitator 15', as shown in Figure 7(a), the rotating shaft 14 and seal rod 20 attached to the existing agitator 15 are lowered and the existing agitator 15 is placed on a hollow receiving base 68 installed above the ground 2.

[0051] 7(b), the connecting pin 63 is removed from the insertion hole 59 of the outer shaft connector 49, and the connecting pin 56 is removed from the insertion hole 55 of the existing agitator 15, separating the outer shaft connector 49 of the connecting adapter 47 and the outer agitator blade connector 50, and separating the inner shaft connector 48 of the connecting adapter 47 and the inner blade shaft 26 of the existing agitator 15. This separates the existing agitator 15 and outer agitator blade connector 50 from the rotating shaft 14 and seal rod 20.

[0052] Next, the existing agitator 15 and outer agitator blade connector 50 are separated from the rotating shaft 14 and seal rod 20, and the inner shaft connector 48 and outer shaft connector 49 of the connecting adapter 47 are raised and moved, and then lowered toward another agitator 15' different from the existing agitator 15, which is placed on a hollow support 69 installed above the ground 2, as shown in Figure 7(c). A connecting pin 63 is inserted through the insertion hole 59 of the outer shaft connector 49, and a connecting pin 56 is inserted through the insertion hole 55 of the other agitator 15', connecting the outer shaft connector 49 of the connecting adapter 47 to the outer agitator blade connector 50, and connecting the inner shaft connector 48 of the connecting adapter 47 to the inner blade shaft 26 of the other agitator 15'. This connects the other agitator 15' to the rotating shaft 14 and seal rod 20. Furthermore, the outer agitator blade connector 50 attached to the other agitator 15' may be an outer agitator blade connector 50 different from the outer agitator blade connector 50 attached to the existing agitator 15, or the outer agitator blade connector 50 attached to the existing agitator 15 may be removed and used.

[0053] Next, as shown in Figure 7(d), the excavation body 22' is attached to the tip (lower end) of the other agitator 15'. This allows the existing agitator 15 attached to the ground improvement device 1 via the connecting adapter 47 to be replaced with the other agitator 15'.

[0054] Furthermore, the agitator 15 attached to the soil improvement device 1 via the connecting adapter 47 can be replaced with not only another agitator 15' but also another excavator 70 using the connecting adapter 47.

[0055] In this case, as explained using Figures 7(a) and (b) above, the rotating shaft 14 and seal rod 20 from which the existing stirring device 15 and outer stirring blade connector 50 have been separated, as well as the inner shaft connector 48 and outer shaft connector 49 of the connecting adapter 47, are raised and moved, and as shown in Figure 8(a), they are lowered toward the outer stirring blade connector 50 placed on a support 71 installed on the top of the ground 2, and a connecting pin 63 is inserted through the insertion hole 59 of the outer shaft connector 49 to connect the outer shaft connector 49 of the connecting adapter 47 and the outer stirring blade connector 50.

[0056] Next, as shown in FIG. 8(b), a hollow cylindrical protective cover 72 is placed on the support 71, and the rotating shaft 14, seal rod 20, and connecting adapter 47 are lowered toward the protective cover 72, and the protective cover 72 is attached to the lower end of the outer agitator blade connector 50. Here, when the excavation device 70 is attached to the soil improvement device 1, only the inner shaft 16 is used, and the outer shaft 17 is not. Therefore, the protective cover 72 is attached to the lower part of the outer agitator blade connector 50 to protect the outer agitator blade connector 50, which is interlocked and connected to the outer shaft 17 via the outer shaft connector 49. Note that the outer agitator blade connector 50 may be different from the outer agitator blade connector 50 attached to the existing agitator 15, or the outer agitator blade connector 50 attached to the existing agitator 15 may be removed and used. The protective cover 72 may also be attached to the lower part of the outer agitator blade connector 50 in advance.

[0057] Next, as shown in Figure 8(c), the rotating shaft 14, seal rod 20 and connecting adapter 47 are lowered toward the drilling device 70 installed on the top of the ground 2, and the connecting pin 56 is inserted through the insertion hole 73 of the drilling device 70 to connect the inner shaft connector 48 of the connecting adapter 47 to the drilling device 70. This makes it possible to attach the drilling device 70 to the ground improvement device 1 via the connecting adapter 47, as shown in Figure 8(d).

[0058] As explained above, the ground improvement device 1 is a device that improves the ground 2 by interlocking and connecting the agitator 15 to the rotating shaft 14, which has a hollow outer shaft 17 arranged in a double-tube shape outside the inner shaft 16, and by agitating and mixing the soil and ground improvement material within the ground 2, and the rotating shaft 14 and the agitator 15 are interlocked and connected via a connecting adapter 47, so that the existing agitator 15 can be replaced with another agitator 15' or an excavation device 70 via the connecting adapter 47.

[0059] Therefore, in the soil improvement device 1 configured as described above, the mixing device 15 already installed in the soil improvement device 1 can be easily changed to another mixing device 15′ or an excavation device 70 by using the connection adapter 47.

[0060] In addition, the above-mentioned ground improvement device 1 is configured so that a connecting adapter 47 is provided between the seal rod 20 and the stirring device 15 to prevent soil and ground improvement material from flowing in between the inner shaft 16 and the outer shaft 17 of the rotating shaft 14.

[0061] Therefore, with the ground improvement device 1 having the above configuration, it is possible to omit the long-term work of removing soil and ground improvement materials that have adhered to the seal rod 20, etc. when replacing the mixing device 15, thereby reducing the effort and time required to replace the mixing device 15.

[0062] In addition, the ground improvement device 1 has, as connecting adapters 47, an inner shaft connector 48 that detachably connects the inner shaft 16 of the rotating shaft 14 and the inner agitator blade 29 of the agitator 15, an outer shaft connector 49 that is hollow outside the inner shaft connector 48 and operatively connected to the outer shaft 17 of the rotating shaft 14, and an outer agitator blade connector 50 that is hollow outside the inner shaft connector 48 and operatively connected to the outer agitator blade 30 of the agitator 15, and is configured so that the outer shaft connector 49 and the outer agitator blade connector 50 can be detachably connected.

[0063] Therefore, in the ground improvement device 1 having the above configuration, the rotating shaft 14 and the agitator 15 can be easily attached or detached, so that the labor and time required to replace the agitator 15 can be further reduced.

[0064] In addition, the above-mentioned ground improvement method is a method for improving the ground 2 by interlocking and connecting a mixing device 15 to a rotating shaft 14 having a hollow outer shaft 17 attached to the outside of an inner shaft 16 in a double-tube shape, and mixing and stirring soil and ground improvement material within the ground 2. The rotating shaft 14 and the mixing device 15 are interlocked and connected via a connecting adapter 47, and the existing mixing device 15 is replaced with another mixing device 15' or an excavation device 70 via the connecting adapter 47.

[0065] Therefore, in the ground improvement method configured as above, the mixing device 15 already installed in the ground improvement device 1 can be easily changed to another mixing device 15′ or an excavation device 70 by using the connection adapter 47.

[0066] Furthermore, the ground improvement method has, as the connecting adapter 47, an inner shaft connector 48 that detachably connects the inner shaft 16 of the rotating shaft 14 and the inner agitating blade 29 of the agitator 15, an outer shaft connector 49 that is provided hollow outside the inner shaft connector 48 and is operatively connected to the outer shaft 17 of the rotating shaft 14, and an outer agitating blade connector 50 that is provided hollow outside the inner shaft connector 48 and is operatively connected to the outer agitating blade 30 of the agitator 15, so that the outer shaft connector 49 and the outer agitating blade connector 50 can be detachably connected, and the inner shaft connector 48 of the connecting adapter 47 can be detached from the inner agitating blade 29 of the existing agitator 15, and the connecting adapter 47 can be attached to the outer shaft connector 49 and the outer agitating blade connector 50. The existing agitator 15 is removed from the rotating shaft 14 by detaching the outer shaft connector 49 from the outer agitator blade connector 50 which is operatively connected to the existing agitator 15, and then the inner shaft connector 48 of the connecting adapter 47 is operatively connected to another agitator 15' or excavation device 70, and the outer shaft connector 49 of the connecting adapter 47 is connected to the outer agitator blade connector 50 which is operatively connected to the other agitator 15' or excavation device 70, thereby attaching the other agitator 15' or excavation device 70 to the rotating shaft 14, and the existing agitator 15 is replaced with the other agitator 15' or excavation device 70 via the connecting adapter 47.

[0067] Therefore, in the ground improvement method configured as described above, the rotating shaft 14 and the agitator 15 can be easily attached or detached, so the labor and time required to replace the agitator 15 can be further reduced. [Explanation of symbols]

[0068] 1 Soil improvement equipment 2 Soil 3 Heavy equipment 4 Posts 5 Ground improvement mechanism 6 Ground improvement material supply mechanism 7 Swivel joint 8 Ground improvement material storage tank 9 Water tank 10 Ground improvement material mixing plant 11 Ground improvement material discharge pump 12 Lifting support 13 driving body 14 rotating shaft 15,15' Stirring device 16 Inner shaft 17 outer shaft 18 drive motor 19 Reverse transmission 20 Seal rod 21 Agitating blade body 22, 22' Excavation body 23,24 Exterior body 25 Inflow prevention body 26 Inner wing shaft 27 Outer wing shaft 28 Innermost stirring blade 29 Inner stirring blade 30 outer stirring blade 31 innermost stirring blade piece 32 Inner stirring blade piece 33 Inner stirring blade upper piece 34 Inner stirring blade middle piece 35 Inner stirring blade lower piece 36 Ring body 37 Stirring piece 38 Connecting piece 39 Outer stirring blade piece 40 Upper part of outer stirring blade 41 Midway part of outer stirring blade 42 outer stirring blade lower piece 43 annular body 44 stirring piece 45 excavation blade 46 Drilling bit 47 Connecting adapter 48 Inner shaft connection body 49 Outer shaft connection body 50 outer stirring blade connecting body 51 insertion recess 52 Insertion hole 53 Insertion protrusion 54 Connecting pin 55 Insertion hole 56 Connecting pin 57 Flange 58 Body 59 Insertion hole 60 flange 61 body 62 Insertion groove 63 Connecting pin 64,65 Insertion groove 66~69 Receptacle 70 Drilling equipment 71 Receiving platform 72 Protective cover 73 Insertion hole

Claims

1. A ground improvement device that improves the ground by stirring and mixing soil and soil improvement materials in the ground by connecting a mixing device to a rotating shaft that has a hollow outer shaft in a double-tube shape outside the inner shaft, A ground improvement device characterized in that the rotating shaft and the agitator are linked together via a connecting adapter, making it possible to replace an existing agitator with another agitator or excavation device via the connecting adapter.

2. The ground improvement device described in claim 1, characterized in that the connecting adapter is provided between the seal rod and the stirring device to prevent soil and ground improvement material from flowing in between the inner shaft and the outer shaft of the rotating shaft.

3. The connecting adapter has an inner shaft connector that detachably connects the inner shaft of the rotating shaft and the inner agitator blade of the agitator device, an outer shaft connector that is hollow outside the inner shaft connector and detachably connects the outer shaft of the rotating shaft, and an outer agitator blade connector that is hollow outside the inner shaft connector and detachably connects the outer shaft of the rotating shaft, and an outer agitator blade connector that is hollow outside the inner shaft connector and detachably connects the outer agitator blade of the agitator device, characterized in that the outer shaft connector and the outer agitator blade connector can be detachably connected.

4. This is a ground improvement method in which a mixing device is connected to a rotating shaft that has a hollow outer shaft attached to the outside of an inner shaft in a double-tube configuration, and the soil and soil improvement material are mixed and stirred in the ground. A ground improvement method characterized by connecting a rotating shaft and an agitator via a connecting adapter, and replacing an existing agitator with another agitator or excavator via the connecting adapter.

5. The connecting adapter has an inner shaft connector that detachably connects the inner shaft of the rotating shaft and the inner stirring blade of the stirring device, an outer shaft connector that is hollow outside the inner shaft connector and is connected to the outer shaft of the rotating shaft, and an outer stirring blade connector that is hollow outside the inner shaft connector and is connected to the outer stirring blade of the stirring device, and the outer shaft connector and the outer stirring blade connector can be detachably connected, The inner shaft connector of the connecting adapter is detached from the inner agitating blade of the existing agitator, and the outer shaft connector of the connecting adapter is detached from the outer agitating blade connector interlocked and connected to the existing agitator, thereby removing the existing agitator from the rotating shaft, Thereafter, the inner shaft connector of the connecting adapter is interlocked and connected to another agitator or excavator, and the outer shaft connector of the connecting adapter is connected to the outer agitator blade connector interlocked and connected to the other agitator or excavator, thereby attaching the other agitator or excavator to the rotating shaft, 5. The ground improvement method according to claim 4, wherein the existing mixing device is replaced with another mixing device or excavation device via a connecting adapter.

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