KR100942714B1 - The soil improvement method for which high-pressure injection agiator and this were used - Google Patents

Abstract

PURPOSE: A high pressure injection stirrer and a ground improvement method using the same are provided to reduce the construction number of a curing body by creating a high intensity curing body due to large diameter. CONSTITUTION: A high pressure injection stirrer comprises a triple injection tube(10). The triple injection tube is composed of an inner tube, a middle tube and an outer tube. The inner tube is composed of a hardener flow path(11). A high pressure water flow path(12) is formed between the inner tube and the middle tube. A compression air channel(13) is formed between the middle tube and the outer tube. High pressure water(W) is injected from an injection nozzle on the upper part of the injection nozzle(15). A hardener injection nozzle(16) of the upper part injects hardener and compressed air(A) downward. The hardener injection nozzle(17) of the lower part injects the hardener and the compressed air in the horizontal direction.

Description

High pressure injection agitator and the soil improvement method for which high-pressure injection agiator and this were used}

The present invention relates to a high-pressure jet stirrer and a ground improvement method using the same, in particular, by kinetic energy of the ultra-high pressure injection, destroying the skeletal structure of the ground, and discharges most of the broken granules to the ground by the air lift effect At the same time, the remaining granules and the hardening material are mixed to discharge a relatively small amount of slime and to form a high quality high strength hardened body with a large diameter.

In general, the ground injection method is a method of increasing the strength of the ground by injecting and solidifying a coagulant such as a chemical liquid or a hardening material into the ground. RJP method), high pressure spray stirring method (JSP method) and the like are widely used.

Here, the above-mentioned SIG method is rotated while spraying a jet flow of ultra-high pressure (P = 400 ~ 600㎏ / ㎠) to discharge the soft soil, large diameter cylindrical high diameter (Φ = 1200 ~ 2000㎜) in the discharged space As a method of forming the binder, it is mainly used in the soil layer, sand layer, gravel layer, soft rock layer and viscous soil layer of N <10.

As described above, the SIG method can solve the problems of the surrounding ground uplift due to the injection of high pressure injection, which is a disadvantage of the conventional jet grouting, and the weakening of the ground due to the spout, and the rotational drawing speed of the multi-pipe rod can be adjusted. It is easy to control the size and discharges the soft soils of the limestone cavity or crushing zone with high pressure water and injects hardening material into the discharged space to form the reinforcement ground with excellent ground strength and durability which is completely different from the original ground. Since the substitution method, the strength increase after reinforcement has a significant advantage.

However, the SIG method as described above, when large cavities are interconnected, excessive grout injection occurs, the cement shrinks as the cement hardens, and the ground and the hardener do not come into close contact with each other. This has the disadvantage of causing extra slime.

On the other hand, the SRC method is a method of cutting and relaxing the ground using high-pressure water (0 ~ 800㎏ / ㎠) accompanied by compressed air during drilling, and is a method of mixing the discharged cutting soil with solidified material and reused as an injection material .

As described above, the SRC method is characterized in that the slime discharged during cutting and filling (substituting) is used as a mixture of cutting water and filler, and thus the slime is greatly reduced. It is an eco-friendly method with almost no eco-friendly method, and by adjusting the mixing ratio of the filler, it is possible to adjust the strength suitable for the purpose of improvement, and it does not affect the ground or surrounding structures during construction.

However, the SRC method as described above should be supplemented with the injection material when the amount of discharged soil is small, and the equipment is complicated because the slime is reprocessed and injected, and the soil is clay if the soil is applied to the process. It is impossible to reuse, and when filling the grout injection material, the material separation phenomenon occurs when contacting with the groundwater, and there is a disadvantage that can not substitute the gravel and sandy soil into the cavity.

On the other hand, the above-mentioned RJP method is rotated while spraying the jet of ultra-high pressure (P = 400 ~ 600㎏ / ㎠) and stirred with the soft soil of the base in the ground large diameter cylindrical solidified body of diameter (Φ = 1200 ~ 2000㎜) As a method of forming a metal, it is mainly used in a soil layer, a sand layer, and a viscous soil layer having N <10.

The RJP method as described above can be installed in the city center without vibration and noise, and does not require any auxiliary work, and it is easy to adjust the size of the cross section by adjusting the rotational drawing speed of the multi-pipe rod, and it is easy to adjust the size of the limestone cavity or crushing table with high pressure water. Since the soft soil powder and the hardening material are agitated to integrate with the surrounding ground, there is an advantage of forming a reinforced ground having excellent ground strength and durability.

However, the RJP method as described above is inferior in strength to the hardened body (maximum strength = 60 kg / cm 2) and economical compared to the SIG method, and when large cavities are interconnected, excessive grout injection occurs and cement hardens. There is a disadvantage that the shrinkage is not in close contact with the base and the hardening material, the cavity is generated again by the groundwater and the excess slime due to excessive high pressure water.

On the other hand, the JSP method is a method of forming a cylindrical solidified body having a diameter (Φ = 800 ~ 1000㎜) in the ground by rotating while spraying a jet of high pressure (P = 200kg / ㎠), mainly earth and sand Layer, a viscous soil layer with N <10.

The JSP method as described above can be constructed in any way vertically or inclined, and especially in a narrow place (basement of the building, lower bridge, etc.), it is suitable as a reinforcement method of the existing structure, the arrangement of the circumference It is improved in various ways by the combination of the arrangement, and because it is filled with grout material in the artificially made voids in the ground, there is almost no effect on the neighboring structures or underground burial like the usual chemical injection method.

However, the JSP method as described above is difficult to control quality due to the development of required strength because the hardened body is a kind of soil cement formed by the soil and hardened material, and the strength of the hardened body (maximum strength = 40㎏ / ㎠) and economy compared to the SIG method. This has the disadvantage of falling.

As described above, the general high pressure grouting method as described above causes excessive grout injection when large cavities are interconnected, shrinks as the cement hardens, and causes the cavity to be regenerated by groundwater because the ground and the hardener are not in close contact with each other. , The amount of slime is excessively produced, and in particular, when the general portland cement alone is used in the clay layer, the strength of the improved body is significantly lowered, which causes a problem in the cured body.

Accordingly, the present invention has been made to solve the problems described above, by destroying the skeletal structure of the ground by the kinetic energy of the ultra-high pressure injection, and by the air lift effect, most of the destroyed granules to the ground It is an object of the present invention to provide a high-pressure jet agitating apparatus and a ground improvement method using the same to discharge a small amount of slime and to form a large diameter high quality hardened material by mixing the remaining granules and the hardening material.

The high-pressure jet agitating apparatus according to the present invention for achieving the above object consists of a triple injection tube of the inner tube and the inner tube and the outer tube as a whole, the inner tube between the hardened material flow path, the inner tube and the inner tube between the high pressure water flow path, the middle pipe and A compressed air flow path is formed between the exterior and the high pressure water in the upper position of the injection pipe horizontally in both sides at a predetermined pressure and flow rate from the injection nozzle, and the hardener injection nozzle is positioned differently with respect to the upper and lower parts of the injection pipe. In the high-pressure jet agitating apparatus installed at two locations at the same time opposite to each other, the spraying direction of the hardening material and the compressed air is in the downward direction so that the upper curing material injection nozzle is inclined 10 to 20 °, the lower curing material injection nozzle in the horizontal direction It is characterized in that the injection.

In addition, the ground improvement method using the high-pressure jet stirrer according to the present invention for achieving the above object is to rotate the injection pipe inserted into the ground and at the same time while drawing the high pressure water from the injection nozzle of the upper position of the injection pipe It sprays horizontally to both sides at a predetermined pressure and flow rate, and pressurizes compressed air and hardening material mixed with alkali by-products at a predetermined pressure and flow rate from the upper and lower injection nozzles in the middle of the injection pipe at a predetermined pressure and flow rate, and discharges slime on the ground. While forming the cured body in the ground, the injection direction of the hardening material and the compressed air is characterized in that the injection of the upper curing material injection nozzle is inclined 10 to 20 ° downwards and the injection of the lower curing material (M) in the horizontal direction.

As described above, the high pressure jet agitating apparatus and the ground improvement method using the same according to the present invention have the following effects.

First, the present invention is to spray a large-capacity, high-energy hardening material, there is an advantage that can form a large diameter cured body.

Secondly, the present invention is advantageous in that the construction efficiency is good because the composition process is performed by the large-capacity discharge, and the construction time can be shortened.

Third, the present invention can form a high-strength cured body with a large diameter, there is an advantage that can reduce the number of construction of the cured body.

Hereinafter, with reference to the accompanying drawings, the present invention will be described in detail.

1 is a conceptual diagram showing a state of improving the ground by using a high pressure jet agitating apparatus according to the present invention, Figure 2 is a configuration diagram showing a state of improving the ground using a high pressure jet agitating apparatus according to the present invention. 3 is a longitudinal sectional view showing the high-pressure jet agitating apparatus according to the present invention.

As shown in these figures, the high-pressure jet agitating apparatus according to the present invention is composed of the inner tube, the inner tube and the triple injection tube 10 of the outer tube, and the inner tube between the hardener flow path 11, the inner tube and the inner tube The compressed air flow path 13 is formed between the high pressure water flow passage 12, the heavy pipe and the exterior, and the high pressure water (W) in the upper position of the injection pipe 10 is a predetermined pressure from the injection nozzle 15 And horizontally sprayed horizontally at both sides at a flow rate, wherein the hardener spray nozzles 16 and 17 are installed at two positions simultaneously opposite to different positions with respect to the upper and lower portions of the injection pipe 10. The injection direction of the hardening | curing material M and compressed air A is the downward direction of the hardening | curing material injection nozzle 16 inclined by 10-20 degrees, and the lower hardening | curing material injection nozzle 17 is injected in a horizontal direction.

Here, the swivel (T) is attached to the upper end of the compressed air flow path 13, the compressed air injection hose inner tube 100 is attached to the swivel (T), the compressed air injection hose inner tube (100) A high pressure injection of the alkali by-products forms an injection injection mixing device (I) in which the alkaline by-products can be mixed with compressed air.

Figures 4a to 4d is a process chart showing a process for improving the ground by using a high-pressure jet agitator according to the present invention.

As shown in these drawings, the ground improvement method using the high-pressure jet agitating apparatus according to the present invention while rotating the injection pipe 10 inserted in the ground (G) and at the same time while drawing, the upper portion of the injection pipe 10 The high pressure water W is horizontally sprayed from both sides of the injection nozzle 15 at a predetermined pressure and flow rate, and alkali by-products are discharged from the upper and lower injection nozzles 16 and 17 at the intermediate position of the injection pipe 10. The compressed air (A) and the hardened material (M) are injected at a high pressure and at a predetermined flow rate, and the hardened material (M) and the compressed air (A) are formed by forming a hardened body (S) in the ground (G) while discharging slime on the ground. ) Spraying direction of the upper hardening material injection nozzles (16, 17) is inclined 10 to 20 ° downwards, the lower hardening material (M) spraying direction is injected in the horizontal direction, discharge the slime on the ground (G) It is a construction method of forming hardened | cured material (S) in the inside.

That is, the ground improvement method using the high-pressure jet stirrer according to the present invention, while rotating the injection pipe 10 inserted into the ground (G) while simultaneously lifting the injection nozzles (15, 16, 17) of the injection pipe 10 Compressed air (A) in which the high pressure water (W), the hardening material (M), and the alkali by-products are mixed is injected from to form the hardened body (S) in the ground (G).

The said hardening | curing material (M) consists of 35 to 75 weight% of cement and 25 to 65 weight% of an aluminosilicate-type admixture, and mixes water and hardening | curing material ratio 1: 1 to 1: 1.5.

Here, to promote the thickening and initial strength to the hardening material (M) it may be mixed alone or in a small amount selected from calcium chloride or sodium bicarbonate and sodium hydrogen carbonate,

The aluminosilicate-based admixture is composed of blast furnace slag fine powder or fly ash fine powder, but the present invention mainly uses blast furnace slag fine powder.

Here, the cement is 35 to 80% by weight, wherein when a certain amount of alkali by-product is added, the curing time is extended when less than 45% by weight, and when it exceeds 75% by weight, it is purified within 2 to 3 minutes after adding water. . As an admixture added to improve the processability and physical properties of the inorganic binder, aluminosilicate-based latent hydraulic materials such as slag and fly ash, or pozzolan reactive materials are activated in an alkaline solution and reprecipitated into a dense hardened material. It has been used in addition to some inorganic binders in the past. The admixture is activated by destroying glass such as slag by OH-ions of hydrated lime produced in the hydration reaction of the inorganic binder, and then generating components and hydrates of the inorganic binder to increase the initial hydration activity. I can promote it. This hydrate formation reaction tends to be accelerated when the amount of produced or supplied slaked lime is increased.

In the present invention, the curing conditions between the admixture and the inorganic binder component are maintained by maintaining the conditions of alkalinity (pH 12.0 or higher) maintained by slaked lime as the alkaline reaction activator and maintaining the conditions of higher alkalinity (pH 13.0 or higher). It was further promoted to prepare a new inorganic binder.

The cured blast furnace slag fine powder or pozzolanic material used in the present invention has a latent hydraulic property, thereby increasing the initial hydration activity of the inorganic binder due to the addition of a suitable alkaline reaction activator.

Here, the hardening material (M) is to stabilize the high-water soil, such as coastal landfill, soft ground using industrial by-products to quantify the ground by applying this, using conventional cement, or of the solidified material using industrial by-products In this case, the condensation takes a long time until the predetermined strength, or the condensation does not occur, while the present invention is in the alumino-silicate industrial by-products, which is the most by-product of the industrial field, By adding cement by-products and alkali-based by-products, the alkali-based by-products promote the hydration of alumino-silicate industrial by-products without hydration reaction, and the cement by-products serve to develop long-term strength. It is very excellent in improving the compressive strength, which is the most important of the various physical properties that the fire has to have.

As the alumino-silicate-based industrial by-products, for example, blast furnace slag powder, fly ash, or the like may be used. The blast furnace slag powder is a substance suspended in a molten state at high temperature by combining with iron oxide (Al ₂ O ₃ ) and silicon dioxide (SiO ₂ ), the main components of iron ore when working in the blast furnace in the steel mill.

This type of alumino-silicate based industrial by-product generally has a large average particle diameter, and the particle size is controlled through a pretreatment operation through a primary grinding process using a roller mill, a ball mill, or a vibration mill.

The alumino-silicate-based industrial by-products are preferably used in an amount of 30 to 80% by weight.

The gypsum-based compound used for the purpose of long-term strength enhancement in the present invention is the alumino-silicate-based industrial by-products are mixed with water in the target soil to produce ettringite (Ettringite) by the initial hydroponic reaction to produce a solid material do.

That is, since hydration produces needle-like crystals called ettringite, and voids are reduced, cracks due to dry shrinkage of hydrous soft ground are reduced and long-term strength is improved and waterproofing is achieved.

Blast furnace slag causes a latent hydraulic reaction when present with cement and water, and can be used as an excellent raw material by promoting initial hydration reaction when alkaline by-products are mixed.

In addition, the present invention, since the alumino-silicate industrial by-products do not form a hydration reaction such as portland cement, which is commonly used in the early stage, the alkali-based by-products are used to sufficiently release alkaline ions at the beginning of hydration. As a result, the acidic film formed on the alumino-silicate-based material is quickly removed, and Al and Si ions trapped inside react with the cement material to promote hydration.

As the alkali-based by-products, alkali-based by-products generated in ceramic products manufacturing industry, inorganic chemical industry, alloy industry, fertilizer manufacturing industry, paper manufacturing industry, etc. may be used. For example, compounds such as sodium-based, potassium-based and sodium-silica-based compounds may be used. Can be used.

On the other hand, as shown in Figure 1, the high-pressure jet agitating apparatus according to the present invention while pulling up while rotating the injection pipe 10 inserted into the ground (G) and at the same time the injection nozzle of the injection pipe (10) 15) spray high-pressure water (W) on both sides horizontally.

At this time, the high pressure water (W) used is acid silica sol which can neutralize the unreacted alkali by-products included in the slime in addition to the high pressure water (W) to promote slime gelation and at the same time By neutralizing the water in slime and decayed strong alkaline excess, it is possible to prevent contamination by releasing water generated from slime in sewage.

Here, the injection pressure of the high pressure water (W) is 10 to 25 MPa at the source pressure of the high pressure water pump (25).

Further, the discharge amount of the high pressure water W is 50 to 100 l / min.

Here, the discharge amount of the high-pressure water W defines the preceding process diameter together with the injection pressure, and dilutes it when the hardened material M injected from the lower portion rises, and the hardened material M is in a slime state. . In this respect, the discharge amount of the high-pressure water W has a lower limit, and the excessive discharge amount causes an excessive amount of pretreatment diameter, resulting in extra slime.

Thus, the process diameter shown to FIG. 1 becomes 0.5-1.2m, and in balance with the improved diameter by the injection of the hardening | curing material M in a lower position, in the state with relatively small slime amount, You can get an improved view.

As shown in FIG. 1, the hardening material M is pressurized while accompanied by compressed air A mixed with alkali by-products from the respective injection nozzles 16 and 17 at the lower position of the injection tube 10. High pressure spraying is performed at 25 to 50 MPa and a flow rate of 100 to 300 l / min.

As a result, the surrounding soil is also cut while moving a part of the slime soil to the ground by the air rising effect by the compressed air A, and stirred and mixed with the hardening material M to form the hardened body S.

In this case, the separation distance between the high pressure water injection nozzle 15 and the curing agent injection nozzles 16 and 17 is preferably 20 to 120 cm, and the separation distance of the lower curing agent injection nozzle 17 is particularly preferably 45 to 80 cm.

If the separation distance is short, there is a fear that the interference is made to reduce the effect of the present invention.

The injection direction of the compressed air (A) in which the hardening material (M) and the alkali by-products are mixed may be in the horizontal direction, as shown in FIGS. 1 and 3, but the injection position may be changed to a different position with respect to the vertical direction. At the same time, it is more preferable that the upper injection angle is inclined downward and the lower injection is horizontal.

In the latter form, the downward spray line is cut in a dice shape so that the improved surface by the spray in the horizontal direction is inclined, and in particular, in the improvement of the viscous soil, the whole can be improved precisely. In other words, substitution, stirring and mixing by the hardening | curing material M can be performed, making the whole desired improvement part homogeneous.

As for the space | interval of the hardening | curing material injection nozzles 16 and 17 mutually, 10-50 cm is preferable.

As for the inclination angle with the horizontal surface of the upper hardening | curing material injection nozzle 16, 10-20 degrees are preferable.

It is preferable to make the hardening | curing material M into the injection quantity of 100-300 L / min from each hardening | curing material injection nozzle 16 and 17, respectively, and to make injection pressure into 35-50 MPa at the original pressure of a pump.

Moreover, it is preferable that the compressed air A is made into injection quantity about 4-8m <3> / min, respectively, and makes injection pressure into 0.7 Mpa or more from the original pressure of the compressor 23.

The compressor 23 preferably has a pressure of 7 to 12 kg / cm 2.

The injection pressure and the injection amount of the hardening material M mainly define the improved diameter and the processing speed.

In order to obtain a target improved diameter of 2 to 3.8 m, if the pressure is low, the target improved diameter cannot be obtained, and excessive pressure is unnecessary from the target improved diameter.

The lower injection rate is mainly determined from the required processing speed, and the excessive injection amount causes an excessive rise of the hardened material M.

Next, as shown in Figure 2, the high-pressure jet agitating device according to the present invention is a pressure feed hose for pumping the high pressure water (W) to the proximal end of the injection pipe 10, a hardener pressure feed hose for pumping the hardening material (M) And an alkaline by-product, which is a liquid mixed with 10-50 wt% of alkaline by-products and 50-90 wt% of water, in the inner portion of the compressed air pressure-feed hose, and is provided with a compressed air pressure hose for pumping compressed air (A). It is used as a pump to spray high pressure to the nozzle to mix the compressed air and alkali by-products.

The high pressure water W is stored in the water tank 20, and is sent from the water tank 20 to the injection pipe 10 by the ultra high pressure water pump 25 through the high pressure water feeding hose, and also the high pressure water feeding lake. Acid silica sol prepared in an automatic silica sol manufacturing apparatus interconnected with

In addition, in the slurry plant 22, the hardening material M is produced by mixing the hardening material sent from the cement silo 21 through the transport path and the high pressure water W sent from the high pressure water tank 20 through the transport path. From the slurry plant 22, the ultra-high pressure pump 24 is sent to the injection pipe 10 through the hardener pressure feed hose. In addition, the compressed air (A) is sent by the compressor 23 to the injection pipe 10 through the compressed air pressure feed hose.

In this way, the inlet pipe 10 through which the high pressure water (W), the hardener (M), and the compressed air (A) are supplied is a triple tube, and a monitor is mounted at the front end, and the high pressure water (W) and the hardener flow path are located at the center of the proximal end. (11), it consists of three flow paths of the high pressure water flow path 12 in the middle, and the compressed air flow path 13 on the outside.

In addition, the injection pipe 10 is self-punching, and a bit is attached to the discharge port 18.

In this bit, a discharge port 18 for discharging the high pressure water W sent through the high pressure water flow passage 12 is formed.

The inner pipe portion may be attached with a high pressure water injection nozzle 15 for spraying only the high pressure water (W), and communicates with the high pressure water passage in two places at the same time at the same position at the same position in the vertical direction of the injection pipe (10) It is installed, the injection direction of the high-pressure water (W) is both in the horizontal direction on both sides.

In addition, below the position where the high pressure water injection nozzle 15 of the injection pipe 10 is provided, the hardening material injection nozzles 16 and 17 which inject high pressure injection of the hardening | curing material M and compressed air A are provided.

The hardener injection nozzles 16 and 17 are constituted by a nuclear nozzle for injecting the hardener M and a compressed air A around the nuclear nozzle to inject the compressed air nozzles into the hardener flow passage 11 or the compressed air, respectively. It communicates with the flow path 13.

The hardened material injection nozzles 16 and 17 are provided in two positions at the same time as the upper and lower parts of the injection pipe 10 at the same time as the other positions.

The injection direction of the hardening | curing material M and the compressed air A makes the upper hardening | curing material injection nozzles 16 and 17 incline, and the lower direction of the hardening | curing material M injection direction is horizontal.

In addition, the high-pressure water (W) and the hardening material flow path (12, 11) is sent to the cutting water discharge hole (not shown) for ground (G) cutting, or the hardening material (M) to the hardening material injection nozzle (16, 17). .

Improving the ground (G) by using the injection pipe 10 as shown in Figure 2, using a cloth mill, such as a boring machine, the tip of the injection pipe 10 discharges the cutting water to the discharge hole In the meantime, the ground G until the discharge port 18 of the injection pipe 10 reaches the ground G predetermined lower limit position is disposed, and the injection pipe 10 is disposed at a predetermined position.

And when pulling up while rotating the injection pipe | tube 10, the hardening body S as mentioned above can be formed.

1 is a conceptual diagram showing a state to improve the ground by using a high-pressure jet stirrer according to the present invention,

Figure 2 is a block diagram showing a state to improve the ground by using a high-pressure jet agitator according to the present invention,

Figure 3 is a longitudinal sectional view showing a high-pressure jet stirrer according to the present invention,

Figures 4a to 4d is a process chart showing the process of improving the ground by using a high-pressure jet agitator according to the present invention.

Explanation of symbols on the main parts of the drawing

10: injection tube 11: euro

12: Euro 13: Euro

15: Injection nozzle 16: Injection nozzle

17: injection nozzle 18: discharge port

20: water tank 21: cement silo

22: slurry plant 23: compressor

24: ultra high pressure pump 25: high pressure water pump

26: high-pressure jet stirrer 27: vacuum pump

100: compressed air injection hose inner tube A: compressed air

G: Ground I: Spray Injection Mixer

M: hardening material S: hardening body

T: Swivel W: High Pressure Water

Claims (6)

The inner tube is composed of a triple injection tube 10 of the inner tube and the middle tube and the outer tube, and the inner tube inside the hardening material flow passage 11, the high pressure water passage 12 between the inner tube and the middle tube, compressed air between the inner tube and the outer tube. A flow path 13 is formed, the high pressure water (W) in the upper position of the injection pipe 10 is injected horizontally in both sides at a predetermined pressure and flow rate from the injection nozzle 15, the hardener injection nozzle (16, In the high-pressure jet agitating apparatus 17, which is installed at two positions at the same time opposite to the other positions with respect to the upper and lower portions of the injection pipe 10, A swivel (T) is attached to the upper end of the compressed air flow path (13), the compressed air injection hose inner tube 100 is attached to the swivel (T), the alkali-based to the compressed air injection hose inner tube (100) A high pressure injection of the by-products to form an injection injection mixing device (I) for mixing the alkali by-products with compressed air, the injection direction of the curing material (M) and compressed air (A) is the upper curing material injection nozzle (16) The high pressure jet agitating device, characterized in that 10 to 20 ° inclined downward, the lower hardener injection nozzle 17 is injected in the horizontal direction. delete The high pressure water stirring device of claim 1 is rotated and drawn while rotating the injection pipe 10 inserted into the ground G, and the high pressure water W is discharged from the injection nozzle 15 at the upper position of the injection pipe 10. Compressed air (A) and hardening material (M) mixed with alkali by-products from the upper and lower injection nozzles (16, 17) in the intermediate position of the injection pipe (10) at a predetermined pressure and flow rate, respectively High pressure spraying at high pressure and flow rate, and forming the hardened body (S) in the ground (G) while discharging slime on the ground, the spraying direction of the hardened material (M) and compressed air (A) is the upper hardened material spray nozzle (16, 17) ) Is sprayed in the horizontal direction in the spraying direction of the hardening material (M) in the lower direction inclined 10 to 20 °, The hardening material (M) is made of 35 to 75% by weight of cement, 25 to 65% by weight of aluminosilicate-based admixture, the ratio of water and the hardening material (M) is 1: 1 to 1: 1.5, The aluminosilicate-based admixture is composed of a single or mixed selected from blast furnace slag fine powder or fly ash fine powder, The alkali-based by-product is ground using a high-pressure jet agitator, characterized in that 10 to 50% by weight of these by-products selected from sodium, potassium and sodium-silica-based alone or mixed with 50 to 90% by weight of water. Improvement method. delete delete delete

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