JP2003090189A - Soil excavating tool, civil engineering machine for soil excavation and soil improving construction method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a soil excavating tool, a connecting device, and a soil improving construction method capable of economically high execution work by simple equipment without causing an environmental problem without discharging sludge in soil improving work, and to provide a soil cleaning construction method for economically cleaning polluted soil without discharging the sludge. SOLUTION: This soil excavating tool 1 has a guiding pipe 2, a shaft body 4, and a spiral blade 6 arranged around the shaft body. The sludge is not generated by the soil excavating tool 1 constituted so that a part for installing the spiral blade by the shaft body becomes thick in a central part and becomes thin in both end parts in the shaft direction. The improving work of the weak ground and cleaning of the polluted soil are realized without causing the environmental problem.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The soil excavation tool according to the present invention,
The swivel, connecting device, soil improvement method and soil purification method relate to improvement of soft ground and purification of contaminated soil.

[0002]

2. Description of the Related Art Conventionally, when digging holes in soft ground by a mechanical construction method, stabilizers such as bentonite for preventing collapse are dissolved in water before use, and powder of air and cement and aggregate (sand) are used.
There is a mechanical agitation method that pumps and replaces it with sludge.

In the conventional ground improvement method, the agitation method by ultra-high pressure injection, the auger agitation method by a large crawler pile driving machine and the bit agitation method are mainly used. In the ultra-high pressure injection method, cement is used when the agitation pile is constructed. 20 for milk
Since a high pressure of 40 MPa to 40 MPa is applied and the pile is ejected from the tip of the nozzle to create piles with pressure, a large amount of sludge is discharged, and the auger stirring construction method using a large crawler pile driver has problems in the construction site. It was

The ultra-high pressure jet agitation method allows construction with a relatively compact machine, but produces a large amount of sludge (exhaust slime), which is not environmentally preferable, and if this sludge is to be treated, There is a problem that it is expensive.

On the other hand, in the auger agitation method using a large crawler pile driving machine, the construction machine is large and the place where construction can be performed is limited, and since a large plant must be transported and installed for construction, There is a problem that a large place must be set up and the cost is high.

In recent years, as a result of industrial activities, harmful substances leak into the ground and soil is contaminated. It is important to suppress the emission of harmful substances, but once they have been emitted, there has been no effective solution. Even if a chemical that decomposes and neutralizes harmful substances is sprayed, its effect is limited to the soil on the surface, and it is difficult to treat it deep into the ground, and mechanical digging increases the cost. It can also bring out toxic substances in the ground to the ground.

[Problems to be Solved by the Invention]

It has been already described that the ultrahigh pressure injection stirring method is effective for strengthening the soft ground, but the generated sludge causes environmental problems or cost problems for the treatment. As a promising technique for solving this, Japanese Patent Laid-Open No.
As disclosed in Japanese Patent Laid-Open Publication No. 1-159130, "Mechanical stirring air cement milk mixing pressure feeding method and device", air is pumped by a compressor and air is jetted from the tip of the cutting bit while digging the ground with the cutting bit and drilling holes. After the completion, a technique is described in which cement milk is pumped by a grout pump and the soil excavated by a cutting bit and the cement milk are stirred to form an underground pile. According to this technology, the soil that has been cut and the cement milk are thoroughly stirred to form underground piles so that the sludge is not discharged to the ground, environmental problems are not caused, and the soil is cheap and simple. Reinforcement work can be performed. The present invention relates to the invention described in Japanese Unexamined Patent Publication No. 2001-159130, and provides a soil excavating tool, a swivel, a connecting device, a soil improving method and a soil purifying method for further developing the invention. , It is an object of the present invention to solve the problems of environmental problems due to the generation of sludge due to the conventional construction method and the large cost of large-scale equipment.

[0008]

In order to achieve the above-mentioned object, the soil excavation tool of the present invention is a soil excavation tool having a leading conduit, a shaft and a spiral blade attached around the shaft. The portion of the shaft body to which the spiral blade is attached is configured such that the central portion is thick and both end portions are thin along the axial direction. By providing the upper and lower surfaces of the spiral blade with claws, the soil can be stirred more effectively. In addition, the claws are plate-shaped and provided in a direction in contact with the circumference centered on the shaft body so that stirring can be performed smoothly. Further, the claws are rectangular plate-shaped and claws on the upper surface of the spiral blade. The angle on the advancing direction side during rotation when the spiral blade moves downward is cut off, and the claw on the lower surface of the spiral blade has the angle on the advancing direction side during rotation when the spiral blade advances upward. It can also be configured to be cut out to allow the nails to stir the soil and the spiral blades to move back and forth more smoothly.

In order to achieve the above object, the swivel of the present invention rotatably supports a soil excavating tool, and an air inlet and an injecting agent inlet are provided in a non-rotating portion. A rotary shaft is rotatably attached to the rotary part, and the rotary shaft is a double pipe consisting of an inner pipe and an outer pipe. Either the air inlet or the injectant inlet formed by the hollow part inside the inner pipe And the space between the inner pipe and the outer pipe is connected to the other one so that the fluid can pass therethrough.

In order to achieve the above-mentioned object, a connecting device of the present invention is a connecting device for rotating shafts of a civil engineering machine, wherein inner pipes of the rotating shafts that are double pipes and inner pipes and outer pipes of the rotating shafts are double pipes. A space between the spaces has a passage through which a fluid can pass, and a rotation prevention mechanism for preventing relative rotation between the rotation shafts is provided.

In the civil engineering machine of the present invention, the above-mentioned soil excavating tool is attached to the work carriage together with the above-mentioned swivel and connecting device, and the soil excavating tool is rotated through the connecting device.

In order to achieve the above-mentioned object, the soil improvement method of the present invention has a leading conduit, a shaft and a spiral blade attached around the shaft, and the spiral blade is formed by the shaft. The part to which is attached is configured such that the central part is thick and both ends are thin along the axial direction, and the soil excavation tool provided with claws on the upper surface and the lower surface of the spiral blade is rotated,
And excavating the soil while ejecting compressed air from the front conduit,
After reaching a predetermined depth, while rotating the soil excavation tool in reverse and stirring the soil, cement milk is injected from the spiral blade part to mix the soil and cement milk, and create an improved body in the soil. is there. A soil purification method can also be realized by using a chemical agent that purifies pollutants in soil instead of cement milk as an injecting agent.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. 1 is a perspective view showing an example of a soil excavating tool according to the present invention, FIG. 2 is a front view thereof, and FIG. 3 is a bottom view thereof. The soil excavation tool 1 according to the present invention is a loop type bit having a spiral blade around a shaft body. It has a tip conduit 2 at its tip and is provided with a cutting tip 3. While cutting the ground with the cutting tip 3, the front conduit 2 enters the ground. A shaft body 4 is provided following the front conduit 2, and spiral blades 5 are provided around the shaft body 4. Although the shaft body 4 is hollow, as shown in FIG. 2, the portion provided with the spiral blade 5 is configured such that the central portion is thick and both end portions are thin along the axial direction. Here, as shown in FIG. 2, the shape is such that a cone is connected to both sides of a cylinder, and the diameter increases from both ends toward the center. Also, when viewed in the overall shape including the loop-shaped blade 5, the diameter is increased as a whole from both end portions toward the central portion. The maximum diameter of the loop-shaped blade 5 is preferably 400 mm or more in order not to generate sludge.
It is preferably 2000 mm or less so that the scale of the equipment is not too large. In this example, the loop-shaped blade 5
Has a maximum diameter of 1000 mm. Further, the length of the shaft body 4 is about 800 mm, the central portion has a constant thickness of about 160 mm, and the shaft diameter changes at a constant rate from about 140 mm to about 400 mm in the upper and lower range of about 320 mm. The taper angle is about 22 °. As will be described later, the taper angle of the shaft body 4 has a useful function for smoothly feeding the earth and sand backward when the loop-shaped blades 5 advance in the ground, but 22 ° is necessary for sufficiently exerting such a function. It is preferable to adjust the degree. The loop-shaped blades 5 are arranged at a pitch such that they make one round every 160 mm in the axial direction, and make five rounds along the length of the shaft body 4. In the range where the shaft body 4 is tapered, the outer diameter of the loop-shaped blade 5 increases toward the central portion at a constant rate. On the other hand, in the range where the thickness of the shaft body 4 is constant, the outer diameter of the loop blade 5 is also constant. In this example, the loop-shaped blade 5 makes a complete circle with the maximum outer diameter, and the outer shape forms a perfect circle when seen from the bottom view, so the shaft may shake when digging. Instead of going straight.

Although the shaft body 4 is hollow, an inner tube is provided inside, and the inner tube is connected to an injecting agent injection nozzle 7 (injecting agent discharge port). The injection agent injection nozzle 7 is provided outward at the position where the shaft body 4 has the largest diameter. In this example, two injection agent injection nozzles 7 are provided, but three or more injection agents may be provided. Further, other than being completely perpendicular to the shaft body 4, it may be tilted to some extent. A gap between the shaft body and the inner pipe serves as a passage for compressed air, and compressed air can be ejected from the tip of the front conduit 2.

A plurality of rectangular plate-shaped claws 6 are attached to the upper and lower surfaces of the spiral blade 6, respectively. The claws 6 are provided so as to be in contact with the circumference centered on the shaft body 4, that is, the plate thickness direction of the claws 6 is the radial direction. By installing in this direction, the generation of sludge becomes less likely to occur. Of the rectangular shape of the claw 6, one corner is chamfered. For this chamfer, the corner may be cut off with a straight line or may be rounded. This chamfered corner is oriented according to the direction of rotation of the spiral blade 5. In this example, when digging, the claw 6b provided on the upper surface of the spiral blade 5 rotates counterclockwise in FIG.
Are mounted with the chamfered corners facing the direction of rotation. On the contrary, when pulling up the soil excavation tool 1, it rotates clockwise, but the claw 6a provided on the lower surface of the spiral blade 5 is attached with the chamfered corner facing the clockwise direction. . By orienting in this way, when digging, the claw 6a provided on the lower surface of the spiral blade 5 is agitated sharply and the soil is effectively agitated, while the claw 6b provided on the upper surface is cut and agitated. The soil is smoothly sent to the rear, and it is hard to bite even if stones about the size of a fist are mixed. On the contrary, when pulling up, the claw 6b provided on the upper surface of the spiral blade 5 effectively cuts and agitates the soil, and the claw 6a provided on the lower surface smoothly feeds the soil backward.

FIG. 10 shows an arrangement example of the claws 6 on the spiral blade 5. In this example, the maximum diameter of the spiral blade 5 is 10
00 mm, the claw 6 has a length of 60 mm, a height of 50 mm,
The thickness is 9 mm and the chamfer is C10. The pawls are provided in a fixed order according to the angle of rotation about the axis as seen in FIG. Claws are attached around the outer circumference of the spiral blade 5 every 1/6 round, that is, every 60 °,
One claw is attached near the shaft at the same angle. Then, one claw is attached at a 1/12 circumference, that is, an angle deviated by 30 ° from the angle where the claw is near the outer circumference, but the radial position of this claw is near the middle of the previous two claws. Becomes That is, one claw and two claws are alternately arranged in a zigzag pattern every 30 °. In addition, in the narrow portion near the upper and lower ends of the spiral blade 5, 1
Although the individual claws may be arranged in succession, even in that case, it is preferable that the radial positions are alternately changed. The upper surface and the lower surface of the spiral blade 5 have the same arrangement. Therefore, near the lower end of the spiral blade 5, the claws 6 arranged near the outer circumference
A substantially conical shape is formed by the cutting tip 3 provided in the tip conduit portion, the soil is effectively cut like a drill, and the soil is effectively stirred by the staggered claws. FIG. 11 shows an arrangement example of the claws 6 on the spiral blade 5 having a maximum diameter of 1500 mm. In this case also 1000m
The claws are arranged in almost the same order as in the case of the m diameter, but at the angle where the claws are attached near the outer circumference of the spiral blade 5 and near the shaft body, one claw is also arranged between these two claws. is doing. And at an angle of 30 °, there is a gap of 2 between the three claws.
Arrange the individual nails in a staggered pattern.

Next, an example of the swivel according to the present invention is shown in FIG.
Shown in. The upper part of the swivel 9 is the non-rotating part 10 and does not rotate. The non-rotating part 10 is provided with an injectant introduction port 11 and an air introduction port 12 on its side surface. A rotating shaft 14 is rotatably attached to the non-rotating portion 10 via a bearing 13. The rotating shaft 14 has a double pipe structure composed of an inner pipe 15 and an outer pipe 16. The inner pipe 15 is hollow, and this hollow portion constitutes an injectant passage 17. The injection agent passage 17 is connected so that the injection agent introduced from the injection agent introduction port 11 can pass therethrough. Inner tube 15 and outer tube 1
A gap is also provided between 6 and this gap constitutes an air passage 18. The air passage 18 is connected so that the air introduced from the air inlet 12 can pass through.

7 and 8 show an example of the connection device according to the present invention. The connecting device is composed of a combination of a male coupling 19 and a female coupling 20. Also,
The intermediate rod 22 connects the swivel 9 and the soil excavation device 1 described above. A male coupling 19 is welded to one end of the intermediate rod 22 and a female coupling 20 is welded to the other end. Therefore, by combining the male coupling 19 and the female coupling 20, two intermediate rods will be connected. Here, a part of the inner wall of the male coupling 19 and a part of the outer wall of the female coupling 20 have a quadrangular cross section, and the quadrangular surfaces are in contact with each other as mating surfaces. That is, this mating surface functions as a rotation preventing mechanism that couples the male coupling 19 and the female coupling 20 so as not to rotate with each other. Also, the male coupling 19 and the female coupling 2
No. 0 is fixed by four bolts so as not to shift in the axial direction.

Female coupling 20 and intermediate rod 22
Has a double tube structure including an inner tube and an outer tube, like the rotary shaft 14 of the swivel. A male coupling or a female coupling having a similar structure is also provided at the ends of the swivel 9 and the soil excavation tool 1 so that they can be connected to the intermediate rod 22. In this embodiment, the male coupling 19a provided on the lower portion of the swivel 9 has a slightly different shape from the male coupling 19b provided on the intermediate rod 22, but the engaging portion is common, The female coupling of the rod 22 can be directly connected. The outer diameter of the intermediate rod 22 is preferably in the range of 60 to 250 mm in order to further suppress the generation of sludge, and is about 140 mm in this example.
The length of the intermediate rod 22 is determined in consideration of the work efficiency and the height of the equipment at the time of construction, but if the length of 6m, 4m, or 2m is provided, it can be used for various construction conditions. It will be a versatile system that can handle.

FIG. 9 shows an example of the civil engineering machine according to the present invention. The work carriage 23 is provided with an endless track 24 and is self-propelled, and the entire apparatus can be easily moved at a construction site. A leader 26 is attached to the work carriage 23 via an arm 25 that can move up and down.
The leader 26 is a slide type attachment device that attaches the chuck 27 movably up and down. After the work carriage 23 is moved to the construction site, the angle of the arm 25 is adjusted and the leader 26 is set upright. The uppermost intermediate rod is passed through the chuck 27, and the intermediate rod is gripped by the chuck 27. The swivel 9 is connected to the top middle rod,
The soil excavation tool 1 is connected below the intermediate rod at the bottom. The chuck 27 can rotate the intermediate rod 22 in both forward and reverse directions by hydraulically driving. That is, the intermediate rod 22 causes the rotation of the chuck 27 to rotate the soil excavation tool 1 at the tip.
Acts as a drive shaft transmitting to. An injectant hose 28 and an air hose 29 are connected to the swivel 9, and each hose is connected to a grout pump and a compressor of a plant (not shown). The swivel 9, the intermediate rod 22 and the soil excavation tool 1 each have a double pipe structure, but are connected so that the air and infusate passages are connected by the connection mechanism described above.

When excavating with the soil excavation tool 1, air is sent by a compressor to be ejected from the tip of the soil excavation tool 1, and the spiral blades of the soil excavation tool 1 are rotated so as to advance downward. After digging to some extent, the intermediate rod 22 is added to dig deeper. Since the claw 6a on the upper surface of the spiral blade is cut in the advancing direction side, the sand and sand can be smoothly sent backward even in soil mixed with stones. Further, in order to smoothly feed the cut earth and sand to the rear, the loop of the spiral blade has a shape in which the diameter expands from the tip toward the center, and the diameter decreases toward the upper part. Here, the larger the spiral blade, the stronger the force for pressing down the soil is, which is advantageous, but the resistance is applied to the spiral blade in the ground, and the resistance is large particularly in the large diameter portion of the central loop. If the shaft body has a constant thickness, the blade has a shape that largely protrudes in the central portion, a large force is applied, and the blade is easily damaged.
In addition, the force applied to the shaft body is large and the shaft body is easily damaged. In the soil excavating tool 1 of the present invention, the shaft body 4 has a spiral blade 5
The part to which is attached has a thick central part and thin end parts along the axial direction. Therefore, the spiral blade and the shaft body are strong even in the central part, and the earth and sand are smoothly sent to the rear while digging.
Is less likely to be damaged in the ground, and construction can be performed even on relatively hard ground or clayey places.

After digging to the final depth, the chuck 27
The soil excavation tool 1 is pulled up while reversing the rotation direction of No. 1 and rotating the spiral blade so as to move upward.
At this time, the infusate is introduced from the infusate hose 28 and injected into the ground through the infusate discharge port of the soil excavation tool 1.
At the time of pulling up, the claws on the upper surface of the spiral blade stir the earth and sand. Since the claws on the lower surface of the spiral blade are cut off in the direction of travel at the time of reverse rotation, the sand is likewise smoothly sent backward. Then, in the civil engineering machine and method of construction according to the present invention, mechanical stirring of earth and sand and agitation of earth and sand by jetting of an injecting agent are simultaneously performed, and the cut earth and sand and the injecting agent are efficiently mixed and cut. Sediment is not discharged to the ground as sludge. When pulling up, contrary to when digging, work is done while sequentially removing the intermediate rod. When the soil excavation tool 1 is pulled up, the injection of the infusate is stopped when the soil excavation tool 1 is pulled up to a predetermined height. When the construction of one hole is completed in this way, the work carriage 23 is moved to the next position, and the same construction is repeated.

In the construction, since the intermediate rod 22 is replenished when digging, and the intermediate rod 22 is removed when the digging is performed, the portion protruding above the ground is always kept low, and the support for preventing fall is provided. Since it is not necessary to extend the body, the construction is easy, and the construction can be performed even in a narrow place or a place where the ground is weak. The connection device described above facilitates attachment and detachment of the intermediate rod, and enables smooth supply of air and infusate. Further, in the present invention, since the earth and sand are actively mechanically agitated both when digging and when being pulled up, it is necessary to make a connection so that the intermediate rod 22 does not loosen when rotating in either forward or reverse directions. However, since the connection device is provided with the rotation preventing mechanism, the connection portion does not come loose and come off.

[0024]

[Embodiment 1] This is an example in which the present invention is applied to ground improvement work. High-concentration cement milk is used as an injecting agent.
The cement milk used in this method is a normal one in order to make the strength of the improved body sufficient (for example, injection 1
It is preferable to make the ratio of cement larger than the amount of cement (about 760 kg of m ³ ). Here, when the amount of cement is increased, the specific gravity of the injecting agent is increased and the suction by the pump is likely to be poor. Therefore, it is preferable to add a water reducing agent containing aromatic sulfone and specially modified lignin as main components.
By blending this water-reducing agent, the cement milk can easily flow and can be easily pumped, and the strength of the improved product can be increased. In this example, as a water-reducing agent, a trade name Sunflow SW-2000S (Nippon Paper Manufacturing Co., Ltd.) containing aromatic sulfone and specially modified lignin as main components was used, and 1000 kg of cement and Sunflow SW were added to 1 m ^{3 of} the injecting agent. -2000S 5kg is blended, the compression strength of the improved body 1
MPa was obtained. A method of ejecting cement milk mixed with air at a plant at a low pressure of 0.6 to 2.5 MPa;
There is a method of ejecting cement milk at an ultrahigh pressure of 18.0 to 29.0 MPa. In the latter case of super high pressure jet stirring,
The air and the cement milk are separately fed without being mixed, and the air is jetted downward from the tip of the leading conduit when digging, and the cement milk is jetted laterally from the injectant discharge port 7 beside the spiral blade when it is pulled up. Either way,
The cut earth and sand are mixed with cement milk and constitute an underground pile as an improved body, so they are not discharged as mud on the ground. When pulling up, the spiral blade rotates clockwise in Fig. 3 to draw in the sand from above and stir it.
The mixed soil and cement are strongly pressed down by the blades, so a strong underground pile can be formed and the generation of sludge is strongly suppressed. Therefore, it does not cause environmental problems due to sludge and does not generate a large amount of cost for sludge treatment, making it a construction method that is friendly to the global environment and has excellent workability, economy, and safety. ing.

In the case of super-high-pressure jet stirring, since the cement milk is horizontally jetted at a high pressure, it is possible to construct an improved body in a range wider than the diameter of the spiral blade, which shortens the construction period and makes it economical. It is possible to improve the workability, and it is possible to carry out close working and mutual working of improved bodies, and the overall work can be integrated. For example, when super-high-pressure jet stirring is performed using a spiral blade with a diameter of 1 m, the diameter is 1.6 to 1.8.
It can be formed in a range of m, and the strength of the improved body is high in such a range. When a spiral blade with a diameter of 1.5 m is used, it can be formed with a diameter of about 2.6 m. In the present embodiment, a spiral blade having a diameter of 1 m is used, the rotation speed of the spiral blade is 0.467 rotations per second, the injecting agent discharge pressure is 18 to 22 MPa, and the air discharge amount is 1.5 to 3. 0m ³ /
min, and the air discharge pressure was 0.6 to 0.7 MPa.
It is necessary to pay attention to the injection amount per unit time, and if excessive injection is performed, the effect of the present invention that sludge is not generated may not be exhibited. It is preferable to inject at about 70% of the injection amount per unit time within the limit that does not generate sludge. In this embodiment, the rate is 70 liter / min. Lifting speed (displayed below with the time required to lift 1 m)
Is 3.0 min / m for cohesive soil at C <0.01 N / mm ² (= MPa), 0.01 N / mm ² ≦ C ≦ 0.0
5.0 min for soil of 3 N / mm ² (5 ≦ N ≦ 10)
/ M, for sandy soil with 10 ≦ N ≦ 15, it was set to 6.0 min / m. Further, a grout pump having a capacity of 70 to 150 liters / min was used so as to be able to cope with a spiral blade having a diameter of 1.5 m which is mainly used with an injection amount of about 140 liters / min.

On the other hand, in the case of low pressure ejection, the inner diameter of the injecting agent injection nozzle 7 is 8 to 12 mm, the rotation speed of the spiral blade is 0.467 rotations per second, and the injecting agent discharge pressure is 0.6 to.
The pressure was 2.5 MPa and the injection rate was 50 liters / min.

[0027]

Example 2 This is an example in which the present invention is applied to soil remediation work. In this embodiment, a chemical that decomposes and neutralizes pollutants in soil is used as the injection agent. After digging to the depth required for decontamination, the soil excavating tool 1 is rotated in the reverse direction and pulled up to inject the chemical into the soil. This is effective because the chemical agent is injected while mechanically stirring the earth and sand with the spiral blade 6. Even if the contamination has proceeded to a deep place, the contamination can be removed within the range reached by the soil excavation tool 1. Further, in this embodiment as well, since the mud is not generated, the contaminated earth and sand do not appear on the surface of the earth, and the construction can be performed safely. If super-high-pressure jet stirring is performed in the same manner as in Example 1, a wide range can be completed with a small amount of work.

[0028]

According to the present invention, the earth and sand can be excavated and agitated without discharging the mud, and the environment around the construction site can be protected. The earth and sand are stirred smoothly and effectively in the ground, and moreover, they are not easily damaged in the ground. No large equipment is required for soil improvement or contaminated soil purification, and effective construction can be performed with a short construction period and low cost.

[Brief description of drawings]

FIG. 1 is a perspective view of a soil excavation tool according to the present invention.

FIG. 2 is a front view of the same.

FIG. 3 is a bottom view of the same.

FIG. 4 is a perspective view of a claw of a soil excavation tool.

FIG. 5 is a sectional view of the swivel according to the present invention.

FIG. 6 is a cross-sectional view showing the flow of infusate and air in a swivel.

FIG. 7 is a cross-sectional view of a connecting device and an intermediate rod according to the present invention.

FIG. 8 is a cross-sectional view showing details of a connection device.

FIG. 9 is a front view showing the civil engineering machine of the present invention.

FIG. 10 is a development view showing an arrangement example of claws on a spiral blade.

FIG. 11 is a development view showing another arrangement example of the claws on the spiral blade.

[Explanation of symbols]

1. Soil drilling tools 2. Destination conduit 3. Cutting tip 4. Shaft 5. Spiral blade 6. nail 7. Injectant outlet 8. Air jet 9. Swivel 10. Non-rotating part 11. Injectant inlet 12. Air inlet 13. bearing 14. Axis of rotation 15. Inner pipe 16. Outer tube 17. Injectant passage 18. Air passage 19. Male coupling 20. Female coupling 21. bolt 22. Intermediate rod 23. Work trolley 24. Endless track 25. arm 26. leader 27. Chuck 28. Infusate hose 29. Air hose

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[Procedure amendment]

[Submission date] October 8, 2002 (2002.10.
8)

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be amended] Title of invention

[Correction method] Change

[Correction content]

[Title of the Invention] Soil drilling tool, civil engineering machine for soil drilling, and soil improvement method

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction content]

[0008]

In order to achieve the above object, the soil excavation tool of the present invention is provided with a tip conduit for ejecting compressed air from the tip, a shaft, and a spiral blade attached around the shaft. In the soil excavating tool having, the portion of the shaft body to which the spiral blade is attached is configured such that the central portion is thick and both ends are thin along the axial direction, and the loop of the spiral blade is a tip. The shape is such that the diameter increases from the portion toward the central portion, and the diameter decreases toward the upper portion. By providing a plurality of claws for stirring the soil on the upper surface and the lower surface of the spiral blade, the soil can be stirred more effectively. In addition, the claws are plate-shaped and provided in a direction in contact with the circumference centered on the shaft body so that stirring can be performed smoothly. Further, the claws are rectangular plate-shaped and claws on the upper surface of the spiral blade. The angle on the advancing direction side during rotation when the spiral blade moves downward is cut off, and the claw on the lower surface of the spiral blade has the angle on the advancing direction side during rotation when the spiral blade advances upward. It can also be configured to be cut out to allow the nails to stir the soil and the spiral blades to move back and forth more smoothly.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction content]

In order to achieve the above-mentioned object, the soil improvement method of the present invention has a leading conduit, a shaft, and a spiral blade attached around the shaft, and the spiral blade in the shaft. The part to which is attached is configured such that the central part becomes thicker and the both ends become thinner along the axial direction.The loop of the spiral blade expands from the tip part to the central part, and the diameter increases toward the upper part. It is a small shape, and the soil excavating tool provided with a plurality of claws for stirring the soil on the upper and lower surfaces of the spiral blade is rotated, and the soil is excavated while ejecting compressed air from the leading conduit, After reaching the depth of the soil, the soil excavation tool is rotated in the reverse direction to stir the soil while injecting cement milk from the spiral blade to mix the soil with the cement milk and create an improved body in the soil. A soil purification method can also be realized by using a chemical agent that purifies pollutants in soil instead of cement milk as an injecting agent.

[Procedure correction 6]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Delete

[Procedure Amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Delete

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Sayoko Yamashita             Kochi City Kochi City Godaiyama Nagae 4869 3 Limited             Company Sakawa Civil Engineering (72) Inventor Riki Inaba             Nishimatsuken 1-20-10 Toranomon, Minato-ku, Tokyo             Inside the corporation F-term (reference) 2D029 ED02                 2D040 AB05 AC05 BA02 BC01 BD05                       CA01 CB03 DA03 DA11 DA16                       DC06 EA01 EA21

Claims (8)

[Claims] 1. A soil excavating tool having a front conduit, a shaft, and a spiral blade provided around the shaft, wherein a portion of the shaft to which the spiral blade is attached is central along an axial direction. A soil excavation tool with a thick part and narrow ends. 2. The soil excavating tool according to claim 1, wherein claws are provided on an upper surface and a lower surface of the spiral blade. 3. The soil excavating tool according to claim 2, wherein the claw is plate-shaped, and is provided in a direction in contact with a circumference having a shaft as a center. 4. The lower surface of the spiral blade, wherein the claw has a rectangular plate shape, and the claw on the upper surface of the spiral blade is cut off at an angle on the advancing direction side during rotation when the spiral blade advances downward. The soil excavating tool according to claim 3, wherein the claw has a corner on the advancing direction side during rotation when the spiral blade advances upward. 5. A swivel for rotatably supporting a soil excavation tool, wherein a non-rotating portion is provided with an air introducing port and an injecting agent introducing port, and a non-rotating portion is provided with a rotating shaft rotatably. The rotating shaft is a double pipe consisting of an inner pipe and an outer pipe, and the hollow portion inside the inner pipe has either an air introducing port or an injecting agent introducing port and a space between the inner pipe and the outer pipe. A swivel that allows fluid to pass through to the other side. 6. A connecting device for a rotating shaft of a civil engineering machine, wherein passages are connected to allow passage of a fluid between inner pipes of the rotating shaft which is a double pipe and between spaces between the inner pipe and the outer pipe. Have
And a connection device provided with a rotation prevention mechanism for preventing relative rotation between the connected rotation shafts. 7. A non-rotating portion, which is provided with a) a work carriage, b) an air introducing port and an injecting agent introducing port, and a rotating shaft which is rotatable with respect to the non-rotating part, wherein the rotating shaft is an inner pipe. It is a double tube consisting of an outer tube, and either the air inlet or the injectant inlet formed by the hollow part inside the inner tube and the space between the inner tube and the outer tube can pass the fluid with the other one. A soil excavation tool having a swivel connected to the c), a leading conduit, a shaft, and a spiral blade attached to the periphery of the shaft, wherein the portion of the shaft to which the spiral blade is attached is in the axial direction. A soil excavation tool having a thick central part and narrowed ends, an air outlet in the leading conduit, and an injectant outlet in the spiral blade, and d) the swivel and soil excavation tools. An intermediate shaft which is a double pipe consisting of an inner pipe for connecting a tool and an outer pipe, and e) a double pipe A rotation prevention mechanism is provided which has a passage through which fluid is allowed to pass between the inner tubes of the rotating shafts and between the inner tube and the outer tube and which prevents relative rotation between the rotating shafts. A civil engineering machine consisting of a connecting device and 8. A front conduit, a shaft, and a spiral blade attached to the periphery of the shaft, and a portion of the shaft to which the spiral blade is attached has a thick central portion along the axial direction and has both end portions. After the soil is excavated by rotating the soil excavation tool that is configured to be thin and provided with claws on the upper surface and the lower surface of the spiral blade and ejecting compressed air from the tip conduit, and after reaching a predetermined depth A soil improvement method in which cement milk is injected from a spiral blade while mixing soil with cement milk by rotating the soil excavation tool in reverse and stirring the soil to form an improved body in the soil.