JP4695734B2 - Soil excavation tool and soil improvement method - Google Patents

Description

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

Patent Document 1 has a spiral blade attached to the periphery of the front conduit, the shaft body, and the shaft body, and the portion of the shaft body to which the spiral blade is attached has a thick central portion along the axial direction and both end portions are Rotate a soil excavation tool that is configured to become thin and have claws on the upper and lower surfaces of the spiral blades, and excavate the soil while blowing compressed air from the tip conduit, and after reaching a predetermined depth, the soil Drainage mud containing cement milk on the ground by reversing the excavating tool and injecting cement milk from the spiral blade while mixing the soil and mixing the soil and cement milk to create an improved body in the soil It is described that the improvement work of soft ground is realized without causing environmental problems and causing environmental problems. In Patent Document 2, it is possible to improve the excavation ability by providing soil cutting claws on the outer peripheral portion of the spiral blade, and to realize excavation of soil in a short time even in soil mixed with Dotan Formation or cobblestone. Are listed. Patent Document 3 and Patent Document 4 describe purifying soil by injecting a purifier into the ground while stirring the soil using the same apparatus.

The nails of the soil excavation tool described in Patent Literature 1 to Patent Literature 4 are provided in a state where a substantially rectangular plate material is erected on the upper surface and the lower surface of the spiral blade. And it becomes the shape where one corner | angular part was cut off.
JP 2003-90189 A JP 2004-278034 A JP 2003-251327 A JP 2004-358420 A

The soil excavation tool described in Patent Literatures 1 to 4 can be effectively constructed while being a simple device. Since there is little waste mud on the ground, it is good for the environment, and there is no waste mud treatment cost, so soil reinforcement work and soil purification can be performed at low cost.

The above-mentioned soil excavation tool has plate-like metal claws on spiral blades, and cuts the soil strongly. Further, the soil is agitated and uniformly mixed with the injection material, and has high strength. Build a reinforced body. However, some soils such as clay layers are difficult to cut. A highly versatile soil excavation tool that can effectively cut even in such hard soil and can be constructed under a wide range of conditions is desired.

In addition, a soil excavation tool that can maintain a strong cutting force for a long period of time is desired.

An object of the present invention is to provide a soil excavation tool and a soil improvement method that can be applied effectively even in hard soil and the like, have high versatility, and can be applied with little drainage on the ground.

In order to solve the above-described problems, a soil excavation tool of the present invention includes a shaft body, a soil stirring blade provided outside the shaft body, a soil cutting claw provided on the soil stirring blade, and an external body from the shaft body. The soil stirring blade has a plate-like nail body part, and pointed parts are formed at both ends of the nail body part. Furthermore, it is preferable that the soil stirring blade is spiral, and the maximum diameter d expressed in meters and the number n of soil cutting nails satisfy the following relationship.
270 × d × d <n <600 × d × d

And when the part which can be seen when seeing the soil stirring blade from the tip part of the shaft body is the first region and the part hidden by the front blade is the second region, the soil stirring blade is substantially only in the first region. More preferably, soil cutting nails are provided. The portion of the shaft body to which the soil stirring blade is attached may have a shape in which the central portion is thick and the both end portions are thin along the axial direction, and is substantially the same thickness along the axial direction. Also good.

Further, the soil improvement method of the present invention includes a shaft body, a soil stirring blade provided outside the shaft body, a soil cutting claw provided on the soil stirring blade, and a nozzle extending from the shaft body to the outside. The soil agitating blade has a plate-like nail body portion, and a tip portion is formed at both ends of the nail body portion. After reaching this height, the soil excavation tool is rotated in the reverse direction to inject the injection material from the nozzle while stirring the soil to create an improved body in the soil.

In the soil excavation tool of this invention, the soil agitation blade has a plate-like nail body part, and the tip part is formed at both ends of the nail body part. In a wide range of soils, it has the effect of strengthening soft ground and purifying soils with little drainage. The soil and the injected material can be mixed uniformly, and a high strength and uniform ground improvement body can be created. The excavation speed is improved and a strong cutting force can be maintained for a long time.

The best mode for carrying out the present invention will be described with reference to the drawings. FIG. 1 is a partially sectional front view showing a soil excavating tool, and FIG. 2 is a bottom view thereof.

The soil excavation tool 1 has a tip conduit 2 at its tip, and a tip 3 for cutting the soil is provided at the tip of this tip 2. A shaft body 4 is provided following the tip conduit 2, and a soil stirring blade 5 is provided outside the shaft body 4. Further, a connecting portion 6 is provided on the upper portion of the shaft body 4.

The shaft body 4 may have substantially the same thickness along the axial direction, and the portion to which the soil stirring blade 5 is attached as shown in FIG. 1 may have a shape in which the central portion is thick and both end portions are narrowed along the axial direction. Good. When the diameter of the soil stirring blade 5 is large, the strength becomes higher when the central portion is thicker as shown in FIG.

The soil stirring blade 5 is provided in a spiral shape outside the shaft body 4. In this example, the outer diameter of the soil stirring blade 5 increases at a constant rate toward the center in the range where the shaft body 4 is tapered. On the other hand, in the range where the thickness of the shaft body 4 is constant, the outer diameter of the soil stirring blade 5 is also constant.

An infusate passage 7 is provided inside the shaft body 4 and the connecting portion 6. And the nozzle 8 is provided in the center part vicinity of the shaft body 4 toward the exterior. The nozzle 8 is provided at a position where the diameter of the soil stirring blade 5 is maximized. The tip of the nozzle 8 is provided along the vicinity of the outer edge of the soil stirring blade 5 but protrudes from the soil stirring blade 5. And the protective material 9 is provided so that the protrusion part of this nozzle 8 may be covered.

One or a plurality of nozzles 8 may be provided, but in the example of FIG. 1, there are two nozzles 8, which are arranged at positions shifted from each other by 180 degrees with respect to the shaft body 4. A plate 10 having the same shape as the protective material 9 is also provided at a position shifted by 90 degrees from the nozzle 8 on the outer periphery of the portion where the diameter of the soil stirring blade 5 is maximum.

The soil stirring blade 5 is provided with a large number of soil cutting nails. The soil cutting nail will be described in detail. There are several different types of soil cutting nails.

First, the soil cutting nail 11 provided on the outer periphery of the soil stirring blade 5 will be described. FIG. 3 is a front view showing a soil cutting nail on the outer periphery, and FIG. 4 is a plan view thereof. This type of soil cutting nail 11 includes a metal nail body 11a and a cutting tip 11b attached to the nail body 11a. The cutting tip 11b is made of a special steel having high hardness, has a pointed tip, and a root portion is connected to the nail body portion 11a by brazing or the like. The nail body 11a is a plate-like metal and has pointed ends at both ends. An example of the shape of the nail body portion 11a is as follows. The thickness t is 19 mm, the length L is 60 mm, and the length L ₀ = 20 mm at both ends is a pointed portion 11c. It has a protruding shape. The height is 50 mm. The nail | claw main-body part 11a is attached toward the tangent direction of the outer periphery of the soil stirring blade 5, and the cutting tip 11b is provided downward (front conduit | pipe direction). Then, the cutting tip 11b is attached so as to be inclined in the rotation direction when the soil excavation tool 1 advances downward. This nail | claw 11 for soil cutting is provided from the lower end part of the soil stirring blade 5 to the largest diameter part, and is not provided above it.

Next, the soil cutting nail 12 provided on the lower surface of the soil stirring blade 5 (the surface facing the tip conduit side) will be described. FIG. 5 is a front view showing a soil cutting nail provided on the lower surface of the soil stirring blade 5, and FIG. 6 is a plan view thereof. Similarly to the soil cutting claw 11 provided on the outer peripheral portion, the metal claw main body portion 12a and the cutting tip 12b are included. The shape of the nail body portion 12a is the same as that of the nail body portion 11a of the soil cutting nail 11 provided on the outer peripheral portion, and pointed ends 12c are formed at both ends. The nail body portion 12a is provided along the circumferential direction, and the cutting tip 12b is provided downward and slightly inclined toward the rotation direction when the soil excavation tool 1 advances downward. Here, the nail | claw 12 for soil cutting is arrange | positioned in the area | region which can be seen from the front conduit | pipe direction among the lower surfaces of the soil stirring blade 5. FIG. That is, when the portion visible when the soil stirring blade 5 is viewed from the tip of the shaft body 4 is a first region, and the portion hidden by the front blade is the second region, the soil cutting nail 12 is the first region. It is arranged in the area and is not provided in the second area. This is based on the fact that the soil cutting nails 12 provided in the first region act effectively in cutting and agitation of the soil, while it is not so effective even when provided in the second region.

The soil cutting nail 13 provided on the upper surface (surface facing the connecting portion side) of the soil stirring blade 5 is only the nail body portion and does not have a cutting tip. The nail body is also formed with pointed ends at both ends. When the portion visible when the soil stirring blade 5 is viewed from the connecting portion of the shaft body 4 is defined as the first region and the portion hidden by the front blade is defined as the second region, the soil cutting claws 13 are also disposed in the first region. , not only set the second region.

Further, the protective material 9 and the plate 10 are also provided with soil cutting nails 14. These soil cutting nails 14 are cutting tips. In each of the protective material 9 and the plate 10, a total of six pieces are provided, two on the outer side and two on the side.

In addition, as a result of intensive studies on the number of soil cutting nails, it has been found that there are conditions suitable for cutting and stirring soil at high speed even in hard ground.
The maximum diameter d of the soil stirring blade 5 and the number n of soil cutting nails are 270 × d × d <n <600 × d × d.
When the relationship is satisfied, the effect of the soil cutting nail is the highest. Here, the maximum diameter d is a value displayed in units of meters. n is the number of soil cutting nails, and includes soil cutting nails 11 and 12 having cutting tips and soil cutting nails 13 having no cutting tips. Further, cutting chips provided on the protective material 9 and the plate 10 are also entered as the number n. For example, in Patent Document 1 and Patent Document 2, a figure showing a soil excavation tool having a soil agitating blade with a maximum diameter of 1 m has about 160 nails. The number is increasing, and this improves the ability to cut and agitate. In addition, providing the number n of soil cutting nails in this way also cuts and agitates when applied to a loam excavation tool in which the nozzle described in Patent Document 1 or the like does not protrude from the soil agitating blade. Ability can be improved and it is effective.

Next, a soil improvement method using this soil excavation tool will be described. FIG. 7 shows an example of a construction machine using the soil excavation tool of the present invention. The work carriage 21 is self-propelled with an endless track 22 and can easily move the entire apparatus at a construction site. A leader 24 is attached to the work carriage 21 via an arm 23 that can move up and down. The leader 24 is a sliding attachment device that attaches the chuck 25 so as to be movable up and down. When the work carriage 21 is moved to the construction site, the angle of the arm 23 is adjusted and the leader 24 is set up vertically. The uppermost intermediate rod 26 is passed through the chuck 25, and the intermediate rod 26 is grasped by the chuck 25. A swivel 27 is connected to the uppermost intermediate rod 26, and the soil excavation tool 1 is connected to the lowermost intermediate rod. The chuck 25 can rotate the intermediate rod 26 in both forward and reverse directions by hydraulic drive. That is, the intermediate rod 26 functions as a drive shaft that transmits the rotation of the chuck 25 to the soil excavation tool 1 at the tip. An injectant hose 28 and an air hose 29 are connected to the swivel 27, and each hose is connected to a grout pump and a compressor (not shown) of the plant. The swivel 27, the intermediate rod 26, and the soil excavation tool 1 have a double pipe structure or a triple pipe structure, respectively, but are connected so that the passages of air and infusate are connected.

When digging with the soil excavation tool 1, air is sent by a compressor and ejected from the tip of the soil excavation tool 1, and the soil agitation blade 5 of the soil excavation tool 1 is rotated so as to advance downward. After digging to a certain extent, the intermediate rod 26 is added to dig deeper. Since the soil cutting claws 11 and 12 having the cutting tips 11b and 12b are provided on the outer periphery and the lower surface of the soil stirring blade 5, the soil is effectively removed by the cutting tips 11b and 12b provided in the traveling direction. Excavated. In order to smoothly feed the cut earth and sand, the outer periphery of the soil stirring blade 5 has a shape in which the diameter increases from the tip toward the center and decreases toward the top. In the soil excavation tool 1 in the example of FIG. 1, the portion of the shaft body 4 to which the soil agitation blade 5 is attached has a thick central portion along the axial direction and both ends narrow, and the soil agitation blade 5 also in the central portion. And the shaft 4 is strong, and since the earth and sand are smoothly fed back while digging, the soil excavation tool 1 is less likely to be damaged in the ground during construction, and construction can be performed even in relatively hard ground or clayey places. it can.

When digging to the final depth, the rotation direction of the chuck 25 is reversed, and the soil excavation tool 1 is pulled up while rotating so that the soil agitation blade 5 advances upward. At this time, the injection agent is introduced from the injection agent hose 28 and the injection agent (for example, cement milk) is injected into the ground from the nozzle 8 of the soil excavation tool 1. When pulling up, the soil cutting claws 13 on the upper surface of the soil stirring blade stir the soil. In construction machinery, mechanical agitation of earth and sand and agitation of earth and sand by injection of the injecting agent are performed simultaneously, and the cut earth and sand are efficiently mixed, and the cut earth and sand are discharged to the ground as waste mud. It will not be discharged.

When stirring while spouting the injectant at ultra-high pressure, it is possible to create an improved body in a wider range than the diameter of the soil stirring blade, because the injectant is injected in the lateral direction at high pressure, shortening the construction period and reducing the economy. The improvement of the property can be realized, and the close construction and the mutual construction can be carried out, so that the construction can be integrated as a whole. And in this invention, the nozzle protrudes rather than a soil stirring blade, can inject | pour an injecting agent farther, and can make a construction range wider.

Since the tip portions 11c, 12c, and 13c are provided at both ends of the nail body portions 11a, 12a, and 13a of the soil cutting nail, the tip portion is in the traveling direction when the soil excavation tool 1 rotates in either direction. It is suitable for cutting the soil effectively. Therefore, even a hard soil such as a clay layer can be cut sufficiently. Moreover, since the soil is sufficiently cut, the soil can be uniformly mixed with an injecting agent such as cement milk, and an improved body having high homogeneity and high strength can be created. The tip portions 11c, 12c, and 13c are gradually worn by continued use, but it takes a considerable period of time for the tip portions to completely disappear. Therefore, this powerful soil cutting ability is maintained for a long time.
Furthermore, the number n of soil cutting nails is 270 × d × d <n <600 × d × d with respect to the maximum diameter d of the soil stirring blade.
Since it is provided sufficiently so as to satisfy the above conditions, the ability to cut and agitate the soil is high, and even a hard ground can be constructed in a short time.

When pulling up, the work proceeds while removing the intermediate rods sequentially, contrary to when digging. If it raises to predetermined | prescribed height, injection | pouring of an injection will be stopped and the soil excavation tool 1 will be pulled up. When the construction of one hole is completed in this way, the work carriage 21 is moved to the next position and the same construction is repeated.

Furthermore, a soil purification method using a soil excavation tool will be described. Even when the soil is purified, the construction machine shown in FIG. 7 can be used. Move the work trolley to the place where the soil is to be cleaned and drill it with the soil excavation tool to the required depth. The process until digging may be performed in the same manner as the soil improvement method. When digging down to a predetermined depth, the rotation direction of the chuck 25 is reversed, and the soil excavation tool 1 is pulled up while rotating so that the soil agitation blade 5 advances upward. At this time, a chemical necessary for soil purification is introduced from the injection hose 28 and injected into the ground from the nozzle 8 of the soil excavation tool 1. For example, hydrogen peroxide and iron powder can be used to decompose and remove volatile organic compounds such as organic chlorine compounds such as dioxin and other organic compounds. It is possible to inject a drug far away by the nozzle 8 protruding from the soil stirring blade 5. Since there are a sufficient number of soil cutting nails and the tip of the nail body is formed, the soil is agitated in the ground and the injected drug is evenly mixed with the soil. This construction does not generate waste mud. Accordingly, the soil in the ground can be purified without adversely affecting the surrounding environment because the contaminated earth and sand are not discharged to the ground or the chemicals do not flow to the ground.

A first embodiment of the soil excavation tool will be described. FIG. 8 is a partial cross-sectional front view showing a first embodiment of the soil excavation tool, and FIG. 9 is the same. The maximum diameter of the soil stirring blade 5 is 1500 mm. The shaft body 4 has a diameter of 205 mm at both ends, but the portion to which the soil stirring blades are attached has a shape in which the central portion is thick and the both ends are thin along the axial direction. A pipe having a triple tube structure is provided inside the shaft body 4, and an air passage is provided in addition to a passage for supplying an injection agent to the nozzle 8.

In the example of FIG. 9A, the nozzle 8 protrudes 50 mm from the outer periphery of the maximum diameter portion of the soil stirring blade 5. And the protective material 9 is provided near the location where this nozzle protrudes, and the upper side or the lower side of the protrusion part of the nozzle 8 is covered. Further, an excavation bit is provided on the outer peripheral portion of the protective material 9. Further, a plate 10 having the same shape as that of the protective material 9 is also provided on the outer periphery of the maximum diameter portion of the soil stirring blade 5 at a position shifted by 90 degrees from the position of the nozzle 8. Therefore, in the bottom view, the protective material 9 and the plate 10 are arranged on the same circumference. The protective material 9 and the plate 10 cut the soil and reduce the external force applied to the tip of the nozzle 8 to protect the nozzle 8. By projecting the nozzle 8 in this way, the injection agent can be injected farther.

In FIG. 9B, the nozzle 8 protrudes 100 mm from the outer periphery of the maximum diameter portion of the soil stirring blade 5. Therefore, the rotation radius of the tip of the nozzle 8 is 850 mm, and a wide range of ground reinforcement, soil purification, and the like comparable to conventional soil excavation tools having a soil stirring blade having a diameter of 1700 mm can be performed. In FIG. 9 (c), 150 mm, and in FIG. 9 (d), the 200 mm nozzle 8 protrudes, and has a capacity close to that of a soil excavation tool having soil stirring blades having a diameter of 1800 mm and a diameter of 1900 mm. However, since the diameter of the soil stirring blade 5 is only 1500 mm, the increase in cost is relatively small.

Furthermore, a second embodiment of the soil excavation tool will be described. FIG. 10 is a partially sectional front view showing a second embodiment of the soil excavation tool, and FIG. 11 is a bottom view thereof. The maximum diameter of the soil stirring blade 5 is 400 mm. The shaft body 4 has a diameter of 140 mm over the entire length. A pipe having a triple tube structure is provided inside the shaft body 4, and an air passage is provided in addition to a passage for supplying an injection agent to the nozzle 8.

Also in this example, the nozzle 8 protrudes from the outer periphery of the maximum diameter portion of the soil stirring blade 5. And the protective material 9 is provided near the location where this nozzle protrudes, and the upper side or the lower side of the protrusion part of the nozzle 8 is covered. Further, a plate 10 having the same shape as that of the protective material 9 is also provided on the outer periphery of the maximum diameter portion of the soil stirring blade 5 at a position shifted by 90 degrees from the position of the nozzle 8. In FIG. 11A, the nozzle 8 protrudes 50 mm, and in FIG. 11B, 50 mm.

The present invention can be used as a soil excavation tool for strengthening soft ground or purifying contaminated soil. Since most of the mud is not discharged, the environment is not adversely affected, and the cost of the mud treatment is not required. By stirring the soil while injecting the injection agent from the nozzle tip protruding from the soil stirring blade, a wide range of construction can be efficiently performed with a small device.

It is a partial cross section front view which shows a soil excavation tool. It is the bottom view. It is a front view which shows the nail | claw for soil cutting of an outer peripheral part. It is the same top view. It is a front view which shows the nail | claw for soil cutting of a lower surface. It is the same top view. It is explanatory drawing which shows the construction machine containing a soil excavation tool. It is a partial cross section front view which shows the 1st Example of a soil excavation tool. It is the bottom view. It is a partial cross section front view which shows the 2nd Example of a soil excavation tool. It is the bottom view.

Explanation of symbols

1. Soil excavation tool2. Tip conduit3. Cutting bit 4. 4. Shaft body 5. Soil agitation blade Connection part 7. Infusate passage 8. Nozzle 9. Protective material 10. Plates 11, 12, 13, 14. Soil cutting nails 21. Work carriage 22. Endless track 23. Arm 24. Leader 25. Chuck 26. Intermediate pipe 27. Swivel 28. Injectant hose 29. Air hose

Claims (4)

It has a shaft, a soil stirring blade provided outside the shaft, a soil cutting nail provided on the soil stirring blade, and a nozzle extending from the shaft to the outside. The soil stirring blade is a plate-like nail. A soil excavation tool having a main body part and having pointed parts formed at both ends of the nail main body part. The soil excavation tool according to claim 1, wherein the soil stirring blade has a spiral shape, and the maximum diameter d (value expressed in units of meters) and the number n of soil cutting nails satisfy the following relationship.
270 × d × d <n <600 × d × d When the portion visible when the soil stirring blade is viewed from the tip of the shaft body is defined as the first region and the portion hidden by the front blade is defined as the second region, the soil cutting blade is substantially cut into the soil stirring blade only in the first region. The soil excavation tool according to claim 2, wherein a claw is provided. It has a shaft, a soil stirring blade provided outside the shaft, a soil cutting nail provided on the soil stirring blade, and a nozzle extending from the shaft to the outside. The soil stirring blade is a plate-like nail. Rotating a soil excavation tool characterized by having a main body part and having pointed parts formed at both ends of the nail main body part, and after reversing the soil excavation tool after reaching a predetermined depth A soil improvement method in which an improved material is created in the soil by injecting an injection material from a nozzle while rotating and stirring the soil.

Images