JP5459040B2 - Ground improvement device and ground improvement method - Google Patents

Description

  The present invention is a ground improvement device for creating a hardened body by jetting a cutting fluid from a rod arranged in a guide hole to cut and destroy the ground, and mixing and stirring the cut soil and hardened material by jetting the hardened material, And it relates to the ground improvement method.

  There is known a ground improvement method (jet grouting method) in which the ground is cut by the force of an ultra-high pressure fluid (jet grouting jet), and the hardened material is formed by mixing and stirring the cut soil and the hardened material. This method includes (1) a jet of curing material liquid at ultra-high pressure, (2) a jet air layer around the super-high pressure curing material jet, and (3) a jet of air around the cutting water jet. There is a type in which a layer is provided and the hardener is sprayed at a position lower than the spraying height of the cutting water.

  With regard to the construction method (2), in Patent Document 1, for the purpose of improving the ground in a wider range, a curing material is injected using a superposition nozzle (double nozzle) composed of an inner core nozzle and an outer surrounding nozzle. Things are listed.

  Moreover, regarding the construction method of (3), in Patent Document 2, for the purpose of suppressing the amount of discharged mud, only high-pressure water is jetted laterally from one jet nozzle and provided below the jet nozzle. There is described a method in which a hardened body is formed by jetting compressed air and cement milk from a pair of jet nozzles.

JP 2001-288734 A JP 2003-286717 A

  In the ground improvement method for creating a hardened body on the ground using the ultrahigh pressure fluid as described above, there is a problem that it is desired to improve the ground over a wide range. In addition, it is necessary to dispose of waste mud mixed with hardeners as industrial waste, and since there are few disposal sites to process this waste mud, we want to reduce the amount of waste mud mixed with hardeners as much as possible. There are also challenges. However, no method has been proposed to solve these problems collectively.

  The present invention has been made in view of such circumstances, and an object of the present invention is to reduce the amount of mud mixed with a hardener as much as possible while improving the ground over a wide range.

The ground improvement device of the present invention is
A cutting nozzle that is arranged in a vertical guide hole formed in the ground and that ejects cutting fluid, a curing material nozzle that ejects a curing material, a foam material nozzle that ejects foam material, and a defoaming that ejects defoaming material Having a rod provided with a material nozzle,
The cutting nozzle is disposed at the tip of the rod,
The hardener nozzle is disposed below the cutting nozzle,
The foam material nozzle is arranged in a height range from the cutting nozzle to the curing material nozzle,
The defoaming material nozzle is disposed below the foam material nozzle.

  According to the present invention, since the foam material is ejected, the fluid of the cut earth and sand becomes high and the soil is easily discharged by mixing the cut soil and the bubbles by the foam material. Furthermore, fine air becomes a large lump by the defoaming material, and a portion where a large amount of air lump exists at the height position of the defoaming material nozzle is formed in a layered manner. Such a layer of air mass makes it difficult for the hardened material to flow above the defoaming material nozzle and is mixed with the cut earth and sand present at a position below the defoaming material nozzle to form a hardened body. . On the other hand, the mud above the defoaming material nozzle rises and is discharged along the guide hole in a state where mixing of the hardener is prevented. For this reason, the amount of waste mud mixed with the hardener can be reduced. Furthermore, since fine air is made into a large lump by the defoaming material, mud can be easily discharged by the air lift effect.

  In the present invention, if the bubble material nozzle is configured as a double nozzle together with the cutting nozzle, and the bubble material is ejected along the outer periphery of the cutting fluid ejected from the cutting nozzle, Since the bubble material layer surrounds the outer periphery to reduce the resistance, the cutting fluid can be sprayed further. Thereby, the ground of a wider range can be improved.

  In the present invention, if the curing material nozzle and the defoaming material nozzle are arranged on a stirring blade attached in a direction crossing the rod at a position below the cutting nozzle, the soil stirred by the stirring blade Since the defoaming material and the curing material are sprayed on the surface, the defoaming can be reliably performed, and the curing material can be sufficiently mixed with the cut soil.

  In the present invention, the curing material nozzle is arranged on the stirring blade so that the curing material is jetted downward, and the defoaming material nozzle is arranged so that the defoaming material is jetted upward. When it arrange | positions to a stirring blade, the bubble enlarged with the defoaming material and a hardening material become difficult to mix, and mixing of the hardening material to the discharged mud can be suppressed.

  In the present invention, if the curing material nozzle and the defoaming material nozzle are configured by a common nozzle, and the mixed liquid of the curing material and the defoaming material is sprayed from the common nozzle, the configuration of the rod is simplified. it can.

  In the present invention, a stirrer blade attached in a direction crossing the rod at a position below the cutting nozzle, the curing material nozzle and the defoaming material nozzle are configured by a common nozzle, and the common If a nozzle is disposed at the tip of the stirring blade and the mixed liquid of the curing material and the defoaming material is jetted from the common nozzle, a wider range of ground can be improved.

In addition, the ground improvement method of the present invention,
A cutting nozzle, a curing material nozzle disposed below the cutting nozzle, a foam material nozzle disposed in a height range from the cutting nozzle to the curing material nozzle, and disposed below the foam material nozzle A step of disposing a rod having a defoaming material nozzle at the tip portion in a vertical guide hole formed in the ground with the tip portion facing down;
While rotating cutting fluid from the cutting nozzle, curing material from the curing material nozzle, foaming material from the foam material nozzle, and defoaming material from the defoaming material nozzle, the rod is rotated in the direction around the axis. The process of pulling up with,
To form a hardened body on the ground.

  According to the present invention, the amount of discharged mud mixed with a hardener can be reduced as much as possible while improving the ground in a wide range.

It is a figure explaining a ground improvement apparatus. It is a figure explaining the structure of a rod front-end | tip part. It is a figure explaining the high pressure water and foam material which are ejected from a cutting nozzle and a foam material nozzle, and a figure explaining the liquid mixture of the hardening material and defoaming material which are ejected from a common nozzle. It is a figure which illustrates a ground improvement process typically. It is a figure explaining the creation process of a hardening body. It is a figure explaining embodiment which provided the antifoamer nozzle between the double nozzle and the hardening material nozzle. It is a figure explaining embodiment which provided the antifoamer nozzle in the upper part of the stirring blade, and provided the hardening | curing material nozzle in the lower part. It is a figure explaining embodiment which provided the common nozzle at the front-end | tip of the stirring blade. It is a figure explaining embodiment which provided the other stirring blade below the stirring blade which provided the common nozzle.

  Hereinafter, embodiments of the present invention will be described. As shown in FIG. 1, the ground improvement device includes a cement silo 1, a cement slurry plant 2, a water tank 3, a foam material tank 4, a defoaming material tank 5, a pump 6, a compressor 7, and a rod 8. And a column machine 9.

  The cement silo 1 is a container for storing cement as a hardener. The cement slurry plant 2 is a plant that mixes the cement stored in the cement silo 1 and the water supplied from the water tank 3 to generate cement slurry (hardening material + water). The water tank 3 stores water used in the ground improvement device. The foam material tank 4 is a container for storing the foam material. A foam material is a chemical | medical agent for producing | generating the fine bubble of shaving cream-like. The defoaming material tank 5 is a container for storing the defoaming material. An antifoaming material is a chemical | medical agent for defoaming the bubble produced | generated with the foam material. The pump 6 supplies cement slurry, foam material, antifoam material, and water to the rod 8 in a high pressure state. The compressor 7 compresses air to obtain compressed air. The obtained compressed air is supplied to the rod 8. The rod 8 is disposed in a vertical guide hole GH formed in the ground, and sprays water, cement slurry, or the like from the tip. The rod 8 will be described later. The column machine 9 is a device that rotates the rod 8 inserted into the guide hole GH in the direction around the axis.

  Next, the rod 8 will be described.

  The rod 8 is constituted by a multiple tube such as a triple tube or a quadruple tube. The rod 8 of this embodiment injects the water as cutting fluid, the foam material with compressed air, and the liquid mixture of a cement slurry and a defoaming material. For this reason, the rod 8 is constituted by a triple pipe, for example, as shown in FIGS. 2 (a) to 2 (c), the outer section 8A is used as a passage for compressed air and foam material, and the intermediate section 8B is used as water. And the inner compartment 8C is a passage for a mixture of cement slurry and antifoaming material.

  Nozzles 11 to 13 are arranged at the distal end portion 8a of the rod 8, and a swivel 8b is provided at the proximal end portion. Since the swivel 8b is suspended by the crane CR, the rod 8 is inserted into the guide hole GH with the tip 8a facing downward.

  Nozzles 11 to 13 are provided at the tip 8 a of the rod 8. In this embodiment, as shown to Fig.2 (a)-(c), the cutting nozzle 11 which injects water (cutting fluid), the foam material nozzle 12 which injects a foam material, cement slurry, and a defoaming material. A liquid mixture nozzle 13 (common nozzle) for injecting the liquid mixture is provided at the tip 8a.

  As shown in FIG. 2C, the mixed solution nozzle 13 is provided at the most distal end position in the distal end portion 8a, that is, in the rod insertion state in which the rod 8 is inserted into the guide hole GH. ing. The mixed liquid nozzle 13 communicates with the inner section 8C of the rod 8 and injects the mixed liquid fed through the inner section 8C toward the side. In the present embodiment, the mixed liquid is injected at a pressure of about 2 MPa to 5 MPa. As described above, since the mixed liquid of the cement slurry and the defoaming material is jetted from the mixed liquid nozzle 13, the configuration of the rod 8 can be simplified.

  As shown in FIG. 2B, the cutting nozzle 11 is shifted 180 degrees from the mixed solution nozzle 13 in the circumferential direction (direction around the axis of the rod 8), and the proximal end side (the swivel 8b) with respect to the mixed solution nozzle 13. Side) position, that is, a position above the mixed liquid nozzle 13 in the rod insertion state. The cutting nozzle 11 communicates with the intermediate section 8B of the rod 8 and injects high-pressure water (water for cutting) fed through the intermediate section 8B toward the side. That is, high-pressure water is jetted in the direction opposite to the mixed liquid. In this embodiment, high pressure water is injected at a pressure of about 20 MPa to 50 MPa.

  As shown in FIG. 2A, the foam material nozzle 12 forms a double nozzle together with the cutting nozzle 11. In the present embodiment, the cutting nozzle 11 is disposed on the inner side, and the bubble material nozzle 12 is disposed on the outer side. In other words, the bubble material nozzle 12 having a ring-shaped opening is provided on the outer peripheral portion of the cutting nozzle 11. The bubble material nozzle 12 is communicated with the outer section 8 </ b> A of the rod 8. And the bubble material which is pressure-fed together with the compressed air in the outer section 8A is jetted toward the side. That is, it sprays in the same direction as high-pressure water. In the present embodiment, the bubble material is injected at a pressure of about 0.7 MPa to 1 MPa.

  As shown in FIG. 3 (a), the high-pressure water 14 injected from the cutting nozzle 11 becomes a jet and flows toward the side of the rod 8. In addition, the foam material 15 ejected from the foam material nozzle 12 forms fine bubbles of a shaving cream shape, and flows along the outer periphery of the jet of the high-pressure water 14. Thereby, the layer of the bubble material 15 is formed between the jet of the high-pressure water 14 and the ground to be cut. A so-called bearing effect is exhibited by the layer of the bubble material 15, and the resistance when the injected high-pressure water 14 diffuses in the ground is reduced. As a result, the high-pressure water 14 for cutting can reach far, and a wide range of ground can be cut. The ground thus cut is mixed with water to become mud (slime). Moreover, as shown in FIG.3 (b), the liquid mixture 16 injected from the liquid mixture nozzle 13 turns into the jet flow of the opposite direction to the high pressure water 14 for cutting, and the bubble material 15, and is mixed with said mud. The

  Next, the ground improvement procedure by this ground improvement apparatus will be described.

  In this procedure, a guide hole installation work is first performed to form a guide hole GH in the ground. For example, as shown in FIGS. 4A and 4B, the casing pipe 18 is rotated around the axis while the drilling water is supplied by the boring machine 17, and the casing pipe 18 is embedded in the vertical direction. When the casing pipe 18 is buried, the rod 8 is suspended by the crane CR and the rod 8 is built in the casing pipe 18. And the casing pipe 18 is pulled out and the rod 8 is arrange | positioned in the guide hole GH of a perpendicular direction. Next, as shown in FIG. 4C, the column machine 9 is installed on the ground instead of the boring machine 17, and the rod 8 is supported so as to be rotatable around the axis.

  If the column machine 9 is installed, the cured body X is created on the ground. For example, as shown in FIGS. 4D and 4E, the rod 8 is pulled up in the vertical direction by the crane CR while the rod 8 is rotated in the direction around the axis by the column machine 9. At that time, as described with reference to FIG. 3, the cutting high-pressure water 14 from the cutting nozzle 11 at the tip 8 a, the foaming material 15 from the foaming material nozzle 12, and the cement slurry and defoaming from the mixed solution nozzle 13. Each of the mixed liquids 16 is sprayed. As a result, the ground is destroyed by cutting and the cement slurry and ground soil and sand are mixed and agitated, and a substantially cylindrical hardened body X is formed on the ground.

  Here, the creation of the cured body X will be described. First, as shown to Fig.5 (a), the ground is cut and destroyed because the injected high-pressure water 14 collides with the ground. At this time, the bearing effect is exhibited by the layer of the bubble material 15 injected so as to surround the outer periphery of the high-pressure water 14. Moreover, the fluidity of earth and sand becomes high by mixing bubbles with the earth and sand cut.

  The bearing effect described above makes it difficult for the energy of the high-pressure water 14 to be impaired, and the high-pressure water 14 can be ejected further. As a result, much of the energy of the high-pressure water 14 can be used for cutting and breaking the ground, and a wider range of ground can be cut than when cutting with the high-pressure water 14 alone.

  And as shown in FIG.5 (b), the mixed liquid 16 of a cement slurry and a defoamer is injected from the liquid mixture nozzle 13 in the position below the cutting nozzle 11 or the foam material nozzle 12. FIG. When the liquid mixture 16 is ejected, the defoaming material in the liquid mixture 16 acts to break the film forming the fine bubbles (film of the bubble material 15). As a result, the air becomes larger and larger, resulting in an air mass (air mass). The air mass is generated one after another because the liquid mixture 16 is continuously jetted, and exists in a layer-like state at the height of the liquid mixture nozzle 13. This air mass layer Y makes it difficult for the cement slurry to move upward, and it is mixed and stirred with a part of the cut ground soil and sand below the mixed solution nozzle 13.

  Thereafter, the high pressure water 14 is ejected from the cutting nozzle 11, the foam material 15 is ejected from the foam material nozzle 12, and the mixed liquid 16 is ejected from the common nozzle, while the rod 8 is rotated around the axis and pulled up. Thereby, as shown to FIG.5 (c), (d), the column-shaped hardening body X is formed in a ground.

  The mud SL above the liquid mixture nozzle 13 rises through the gap between the rod 8 and the guide hole GH. The mud SL has a high fluidity because fine bubbles are mixed therein. For this reason, the mud SL can rise smoothly in the gap between the rod 8 and the guide hole GH. Furthermore, since the mud SL rises together with the air mass generated by the defoaming material, it is easily discharged by the so-called air lift effect.

  In this embodiment, the slime bit 19 for collecting the mud SL is formed on the ground surface. The mud SL that has risen through the gap is collected by the slime bit 19 and collected by a vacuum car 20 (see FIG. 1) or a backhoe (not shown).

  Here, regarding the cement slurry, the upward movement of the cement slurry is made difficult by the air mass layer Y. By interposing the air mass layer Y, the mud clay SL collected by the slime bit 19 can be prevented from containing cement (hardening material). And if cement is not contained in the mud SL, this mud can be easily and inexpensively disposed as general construction residual soil. The mud can also be used for other purposes.

=== Other Embodiments ===
FIG. 6 is a diagram for explaining the second embodiment. In this 2nd Embodiment, it replaces with the liquid mixture nozzle 13, and the hardener nozzle 22 which injects the cement slurry 21 (hardener + water) and the defoamer nozzle 24 which injects the defoamer 23 are provided separately. . The defoaming material nozzle 24 is disposed between the cutting nozzle 11 and the foam material nozzle 12 (double nozzle) and the curing material nozzle 22. If comprised in this way, the mud located below the defoaming material nozzle 24 will be in the state by which the bubble was defoamed (the state where the air lump floated). For this reason, the malfunction that a bubble enters in the hardened | cured material X formed can be prevented.

  FIG. 7 is a diagram for explaining the third embodiment. In the third embodiment, a propeller-like stirring blade 25 that can be opened and closed is provided at a position below the cutting nozzle 11, and the curing material nozzle 22 and the defoaming material nozzle 24 are disposed on the stirring blade 25.

  A plurality of the hardener nozzles 22 are provided in the lower part of the stirring blade 25 in an open state in a state of being arranged in the longitudinal direction of the stirring blade 25, and jet the cement slurry 21 downward. In addition, a plurality of antifoaming material nozzles 24 are provided in an upper portion of the stirring blade 25 in an open state in a state of being arranged in the longitudinal direction of the stirring blade 25, and jet the antifoaming material 23 upward.

  In the third embodiment, the cut soil can be reliably stirred by the stirring blade 25. And since the defoaming material 23 is mixed with mud on the upper side of the stirring blade 25, the bubbles can be floated as a lump of air. That is, defoaming can be performed reliably. On the other hand, since the mud after the bubbles have been removed and the cement slurry 21 are mixed and stirred below the stirring blade 25, bubbles can be reliably prevented from remaining in the hardened body X.

  FIG. 8 is a diagram for explaining the fourth embodiment. In the fourth embodiment, the mixed solution nozzle 13 (common nozzle) is disposed at both ends of the stirring blade 25. And the liquid mixture 16 of a cement slurry and an antifoamer is injected toward the side from the liquid mixture nozzle 13. FIG. In this 4th Embodiment, since the liquid mixture 16 is sprayed toward the side from the front-end | tip of the stirring blade 25, a ground is cut and destroyed also by this liquid mixture, and the ground of a wider range can be improved.

  FIG. 9 is a diagram for explaining the fifth embodiment. In the fifth embodiment, another stirring blade 26 (lower stirring blade) is provided below the stirring blade 25 (upper stirring blade) of the fourth embodiment. In this embodiment, the lower stirring blade 26 mixes the mud and the mixed liquid 16. Thereby, a bubble can be broken reliably. Moreover, a cement slurry can be mixed reliably.

  As mentioned above, although several embodiment was described, the description regarding each embodiment is for making an understanding of this invention easy, and does not limit this invention. The present invention can be changed and improved without departing from the spirit and purpose of the present invention, and the present invention naturally includes equivalents thereof.

  For example, regarding the foam material nozzle 12, in each of the above-described embodiments, the foam material nozzle 12 and the cutting nozzle 11 are double nozzles. Not. For example, the bubble material nozzle 12 may be disposed between the mixed solution nozzle 13 (the defoaming material nozzle 24) and the cutting nozzle 11.

  In addition, regarding the cutting fluid, in each of the above embodiments, water having a high pressure is exemplified, but a mixture of fine sand and water or a mixture of bentonite and water may be used as the cutting fluid.

  Moreover, regarding the hardening material, although cement was illustrated in said each embodiment, hardening materials other than cement may be used.

  Moreover, you may combine the technical element of each embodiment mentioned above. For example, by combining the technical elements of the third embodiment and the fourth embodiment, the defoaming material nozzle 24 is disposed on the upper portion of the stirring blade 25, the curing material nozzle 22 is disposed on the lower portion, and the mixed solution nozzle 13 is disposed on both ends. May be provided.

DESCRIPTION OF SYMBOLS 1 Cement silo 2 Cement slurry plant 3 Water tank 4 Foam material tank 5 Antifoam material tank 6 Pump 7 Compressor 8 Rod (8a tip part, 8b swivel)
8A Rod outer section 8B Rod middle section 8C Rod inner section 9 Column machine 11 Cutting nozzle 12 Bubble material nozzle 13 Mixture nozzle 14 High pressure water 15 Bubble material 16 Mixture 17 Boring machine 18 Casing pipe 19 Slime bit 20 Vacuum car 21 Cement slurry 22 Hardening material nozzle 23 Antifoaming material 24 Antifoaming material nozzle 25, 26 Stirring blade CR Crane SL Mud X Hardened body Y Layer of bubble mass

Claims (7)

A cutting nozzle that is arranged in a vertical guide hole formed in the ground and that ejects cutting fluid, a curing material nozzle that ejects a curing material, a foam material nozzle that ejects foam material, and a defoaming that ejects defoaming material Having a rod provided with a material nozzle,
The cutting nozzle is disposed at the tip of the rod,
The hardener nozzle is disposed below the cutting nozzle,
The foam material nozzle is arranged in a height range from the cutting nozzle to the curing material nozzle,
The antifoaming material nozzle is disposed below the foaming material nozzle, and the ground improvement device is characterized in that   2. The ground according to claim 1, wherein the foam material nozzle forms a double nozzle together with the cutting nozzle, and the foam material is ejected along an outer periphery of the cutting fluid ejected from the cutting nozzle. Improved device. A stirring blade attached in a direction crossing the rod at a position below the cutting nozzle of the rod;
The ground improvement device according to claim 1 or 2, wherein the hardening material nozzle and the defoaming material nozzle are arranged on the stirring blade. The hardener nozzle is disposed on the stirring blade so as to spray the hardener downward.
The ground improvement device according to claim 3, wherein the defoaming material nozzle is disposed on the stirring blade so as to spray the defoaming material upward.   The said hardening material nozzle and the said defoaming material nozzle are comprised by a common nozzle, and the liquid mixture of the said hardening material and the said defoaming material is injected from the said common nozzle, The any one of Claim 1 to 3 characterized by the above-mentioned. The ground improvement device described in 1. Having a stirring blade attached in a direction crossing the rod at a position below the cutting nozzle;
The curing material nozzle and the defoaming material nozzle are constituted by a common nozzle, and the common nozzle is disposed at the tip of the stirring blade,
The ground improvement device according to claim 1 or 2, wherein a mixed liquid of the curing material and the defoaming material is sprayed from the common nozzle. A cutting nozzle, a curing material nozzle disposed below the cutting nozzle, a foam material nozzle disposed in a height range from the cutting nozzle to the curing material nozzle, and disposed below the foam material nozzle A step of disposing a rod having a defoaming material nozzle at the tip portion in a vertical guide hole formed in the ground with the tip portion facing down;
While rotating cutting fluid from the cutting nozzle, curing material from the curing material nozzle, foaming material from the foam material nozzle, and defoaming material from the defoaming material nozzle, the rod is rotated in the direction around the axis. The process of pulling up with,
A ground improvement construction method characterized in that a hardened body is formed on the ground by performing the above.

Images