JPH11323335A - Conditioning process for water-containing soil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conditioning process suitable for conditioning and recycling water-containing soil. SOLUTION: A conditioner for water-containing soil containing a water-soluble polymer having a cationic group is mixed with water-containing soil to condition this water-containing soil into a particulate form. Then, the obtained particulate solid matter is added with a hydraulic substance. Otherwise, the conditioner is mixed with water-containing soil using a horizontal axis-type mixer or vertical axis-type mixer to condition the water-containing soil into a particulate form. The water-soluble polymer is more preferably at least one polymer chosen from the group consisting of a polymer obtained by polymerizing a monomer component containing aminoalkyl (meth)acrylates and/or quaternized products thereof, Hofmann degradation products of polyacrylamide, Mannich modified products of polyacrylamide and polyvinyl amines.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for improving hydrated soil, and more particularly, to an improved method for improving hydrated soil, which is suitable for reuse as a substitute for sand, for example. It is about the method.

[0002]

2. Description of the Related Art Generally, for example, in the treatment of construction waste material resulting from excavation work using a cast-in-place pile method, a mud shield method, or the like, excavated soil generated during excavation is supplied by supplying excavated mud to an excavation hole. Is discharged to the outside together with the drilling mud.

[0003] The above-mentioned generated soil is not classified as industrial waste specified in the Waste Disposal and Waste Management Law, because earth and sand are separated and reused for cutting at construction sites. However, excavated muddy water, which has a muddy state, more specifically, a slurry containing a large amount of water together with clay, and exhibits fluidity, cannot be piled up on a standard specification dump truck, and for example, a person can walk on it. Has no state. Therefore, the above drilling mud is
It cannot be used as backfill material as it is, but must be treated as industrial waste in accordance with the Waste Management Law. For this reason, the above-mentioned excavated mud is subjected to dewatering press or the like to carry out solid-liquid separation so that it can be transported or the like. Coalescence and the like are mixed and solidified (improved). The hydrous soil improved by these improvement methods is discarded at a predetermined disposal site such as a landfill disposal site, or the improved hydrous soil is used in civil engineering work in which excavation holes need to be backfilled. Is injected into a wellbore.

[0004] As such an improved method, for example, Japanese Patent Application Laid-Open No. 1-176499 discloses a method of mixing a water-soluble synthetic polymer substance or the like with water-containing soil.

[0005]

However, since water-containing soil must be treated as industrial waste, it requires a great deal of disposal costs. In addition, the final disposal amount of hydrous soil as construction waste material is enormous, and landfill disposal of hydrous soil is difficult every day due to difficulties in obtaining land for final disposal sites to dispose of hydrous soil and opposition from local residents. Has become. Therefore, when the hydrous soil is treated by the above-mentioned conventional improvement method, there is also a problem that it is difficult to secure land for a final disposal site such as a disposal site. For this reason, there is a long-felt need for an improved method capable of reusing water-containing soil.

Incidentally, for example, Japanese Patent Application Laid-Open No. 1-158109 discloses a consolidation method in which a water-soluble cationic polymer compound or the like is mixed with a water-containing soil (soft soil) to consolidate the water-containing soil. Is disclosed. However, in the above consolidation method, when disposing the hydrous soil to a predetermined disposal site such as a landfill disposal site, the hydrous soil can be piled up on a dump truck and transported.
The purpose is to consolidate the entire hydrated soil. That is,
The consolidation method aims at discarding the water-containing soil, and does not aim at reusing it.

[0007] The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide an improved method suitable for improving and reusing water-containing soil.

[0008]

Means for Solving the Problems The present inventors have diligently studied a method for improving hydrous soil in order to achieve the above object. As a result, for example, after improving the hydrous soil to a granular state by mixing the hydrous soil improving agent containing the water-soluble polymer having a cationic group with the hydrous soil, a hydraulic substance is added to the obtained granular solidified product. As a result, it has been found that the water-containing soil can be solidified and reused without being discarded as industrial waste, thereby completing the present invention.

That is, in order to solve the above-mentioned problems, the method for improving a hydrous soil according to the first aspect of the present invention comprises mixing a hydrous soil improving agent containing a water-soluble polymer having a cationic group into the hydrous soil. The method is characterized in that after the hydrous soil is improved to a granular state, a hydraulic substance is added to the obtained granular solidified product.

According to a second aspect of the present invention, there is provided a water-soluble polymer having a cationic group by using a horizontal axis type mixer or a vertical axis type mixer to solve the above problems. By mixing a water-containing soil improver containing water-containing soil with the water-containing soil, the water-containing soil is improved in a granular form.

According to a third aspect of the present invention, there is provided a method for improving a hydrous soil according to the first or second aspect, wherein the water-soluble polymer is an aminoalkyl ( At least one selected from the group consisting of a polymer obtained by polymerizing a monomer component containing meth) acrylate and / or a quaternary product thereof, a Hoffman decomposition product of polyacrylamide, a Mannich modified product of polyacrylamide, and polyvinylamine Is characterized by being a polymer of

According to the above-mentioned method, it is possible to transport the hydrous soil, which is usually discarded as sludge, by truck. For example, a solidified material improved so that a person can walk on it, more preferably, It can be improved to a solidified product having sufficient strength and a predetermined particle size and finely divided into particles. As a result, the improved hydrous soil can be effectively used for backfilling, agricultural and horticultural purposes, and the like, for example, as a substitute for sand, and can be reused as resources. In addition, if the improved hydrous soil is made into a particulate solidified product, water permeability when backfilled on the ground can be improved, and the hydrous soil can be reused in a wider range. As a result, environmental conservation, resource saving, and the life of the disposal site can be prolonged, and the disposal cost of hydrous soil can be reduced.

[0013] In addition, according to the method of the first aspect, the hydraulic substance is added to the granular solid, so that the solid obtained does not disintegrate even when wet with water and is finely divided into particles. State can be maintained. Therefore, the solidified material does not collapse even when it is rained and can be piled up on a construction site, for example, and can be stored easily and at low cost.

Hereinafter, the present invention will be described in detail. The method for improving a hydrous soil according to the present invention comprises mixing a hydrous soil improver containing a water-soluble polymer having a cationic group with the hydrous soil to improve the hydrous soil into granules, and then obtaining a granular solidified product. This is a method of adding a hydraulic substance. Further, the method for improving a hydrous soil according to the present invention comprises mixing a hydrous soil improving agent containing a water-soluble polymer having a cationic group into the hydrous soil using a horizontal axis type mixer or a vertical axis type mixer. This is a method for improving the hydrated soil to a granular form.

The hydrated soil solidified (improved) by the improvement method according to the present invention may be of any type.
Even clay and silt, which had been difficult to reuse in the past, can be used as improved soil, for example, in the “Construction Soil Utilization Technology Manual” (1.
994, published by the Japan Civil Engineering Research Center), solidified matter that does not correspond to construction sludge, that is, solidified matter that can be transported by truck, for example, that can be walked on by humans, more preferably It is possible to obtain a solidified product which has been granulated into particles having sufficient strength and a predetermined particle size.

As the above-mentioned wet soil, specifically, for example, the soil generated at the time of excavation in the excavation work employing the underground continuous wall method, the muddy water shield method or the like is separated into earth and sand and muddy water. Sludge obtained as a dewatered cake, etc. after dewatering press by dewatering press etc .; muddy water generated during construction work is left in a sedimentation tank, sludge obtained as sediment; excavated soil, soft soil Sludge such as hydrated stone powder generated in quarries and quarries.

The hydrated soil is JIS A 1203
(Water content (g))
/ Solid content (g)) x 100 "is 20% to 2
Those within the range of 00% are preferable, and those within the range of 50% to 150% are more preferable. A water-containing soil having a water content of more than 200% has a large water content (hereinafter referred to as "moisture content"), so that a large amount of the improver must be used, and the cost of the improver increases, which is not preferable.

The source of the hydrated soil is not particularly limited, and the hydrated soil may contain bentonite in addition to clay and silt.

As described above, the improved method according to the present invention can be applied irrespective of the source of the hydrous soil.
Among them, it is particularly suitable for hydrous soil generated in the Kanto region. According to the survey of construction by-products, the amount of construction waste generated by the Kanto Regional Construction Bureau is highest in Japan. However, the construction waste generated in the Kanto region,
In general, it contains a large amount of Kanto loam (volcanic ash clayey soil), silt, clay and the like, and it is difficult to solidify into granules. Therefore, while the reuse of hydrous soil containing generated soil generated in the Kanto region is considered desperate, according to the present invention, conventionally, it is difficult to solidify into granular form, the hydrous soil generated in the Kanto region, It can be a solidified product which is finely divided into particles having high strength and a predetermined particle diameter.

The water-soluble polymer (hereinafter simply referred to as a polymer) used as the improver for hydrous soil of the present invention may be any polymer having a cationic group and being water-soluble. Although not particularly limited, a polymer obtained by polymerizing a monomer component containing an aminoalkyl (meth) acrylate and / or a quaternized product thereof, a Hoffman decomposition product of polyacrylamide, a Mannich modified product of polyacrylamide , And at least one polymer selected from the group consisting of polyvinylamine, and among the polymers exemplified above, aminoalkyl (meth)
A polymer obtained by polymerizing a monomer component containing acrylate and / or a quaternary compound thereof is particularly preferred.

The method for producing the above polymer is not particularly limited. The polymer can be easily obtained by polymerizing a monomer component containing a monomer having a cationic group. For example, a polymer obtained by polymerizing a monomer component containing an aminoalkyl (meth) acrylate and / or a quaternary product thereof may be a monomer having a cationic group, such as aminoalkyl (meth) acrylate and / or By polymerizing a monomer component containing the quaternized product, or by copolymerizing the monomer with another monomer copolymerizable with the monomer (hereinafter, simply referred to as other monomer). Thereby, it can be easily obtained. That is, the monomer component contains only the aminoalkyl (meth) acrylate and / or its quaternary product, or the aminoalkyl (meth) acrylate and / or its quaternary product and another monomer And

As the aminoalkyl (meth) acrylate and its quaternary compound, specifically, for example, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, diethylaminopropyl ( Meth) acrylate, dimethylaminopropyl (meth) acrylamide, diethylaminopropyl (meth) acrylamide, and methyl chloride 4 of these monomers
Grade salts and hydrochlorides are exemplified, but are not particularly limited. These monomers may be used alone,
Further, two or more kinds may be used in combination. Among the above exemplified monomers, a methyl chloride quaternary salt of dimethylaminoethyl (meth) acrylate is more preferred.

The above-mentioned other monomer may be any monomer capable of obtaining the polymer according to the present invention, that is, a water-soluble polymer having a cationic group, and is not particularly limited. Absent. That is, the structural unit other than the monomer unit having a cationic group, which constitutes the polymer according to the present invention, is not particularly limited. As other monomers, specifically, for example, acrylic acid, methacrylic acid, crotonic acid, vinyl acetic acid, maleic acid, itaconic acid, mesaconic acid, fumaric acid, citraconic acid, N- (meth)
Acryloyl aspartic acid and monomers having a carboxyl group such as alkali metal salts and ammonium salts of these monomers; 2-acrylamido-2-methylpropanesulfonic acid, (meth) allylsulfonic acid, allyloxybenzenesulfone Acid, 2-hydroxy-3- (2-propenyloxy) propanesulfonic acid, isopropenylsulfonic acid, styrenesulfonic acid, vinylsulfonic acid, allylphosphonic acid, isopropenylphosphonic acid, vinylphosphonic acid, sulfoethyl (meth) acrylate, Sulfonated isoprene, phosphoethyl methacrylate, and
Such as alkali metal salts and ammonium salts of these monomers,
Monoethylenically unsaturated acid; methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, polyethylene glycol (meth) Nonionic monomers such as acrylate, methoxypolyethylene glycol (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate, (meth) allyl alcohol, ethylene oxide adduct of (meth) allyl alcohol, and propylene oxide adduct of (meth) allyl alcohol Vinyl esters such as vinyl acetate, vinyl propionate, vinyl pivalate, vinyl benzoate, and vinyl cinnamate; and alkyl esters such as methyl vinyl ether and ethyl vinyl ether. Vinyl ether; unsaturated alcohols such as 3-methyl-3-buten-1-ol, 3-methyl-2-buten-1-ol and 2-methyl-3-buten-2-ol; and aldehyde groups such as acrolein Vinyl monomer; vinyl monomer containing a nitrile group such as (meth) acrylonitrile; (meth) acrylamide, Nt-butylacrylamide, styrene, N-vinyl-2-pyrrolidone, N-vinyl-5-methyl-2-pyrrolidone , N-vinylacetamide,
A nonionic monomer having a functional group other than the above, such as N-vinylformamide; One of these other monomers may be used alone, or two or more thereof may be used in combination.

In the present invention, the ratio of the monomer having the cationic group in the above monomer component, that is, the ratio of the monomer unit to all the monomer units constituting the polymer is It is preferably at least 5 mol%, more preferably at least 10 mol%.

The method for producing the polymer, that is, the method for polymerizing the monomer component is not particularly limited. For example, a polymerization method using a polymerization initiator such as a radical polymerization initiator; ionizing radiation; Conventionally known various methods such as a polymerization method of irradiating radiation such as rays or ultraviolet rays; a polymerization method of heating; and the like can be employed.

As the radical polymerization initiator, a peroxide-based, redox-based, or azo-based initiator can be used. Specifically, for example, ammonium persulfate, potassium persulfate, hydrogen peroxide, peroxides Peroxides, such as benzoyl and t-butyl peroxide, which are suitably used in peroxides and redox systems; sodium bisulfite, sodium metabisulfite, ammonium ferrous sulfate, L-ascorbic acid, triethanolamine, etc. 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (2-aminopropane)
Dihydrochloride, 2,2'-azobisisobutylamide dihydrate,
Azo initiators such as 2,2′-azobis [2- (2-imidazolin-2-yl) propane] dihydrochloride; and the like, but are not particularly limited. The amount of the polymerization initiator used and the reaction conditions for the polymerization reaction are not particularly limited.

In the present invention, the weight average molecular weight of the obtained polymer is not particularly limited, but may be 100,000
Is more preferably greater than 1,000,000, even more preferably greater than 1,000,000, and particularly preferably greater than 2,000,000.

When the weight average molecular weight of the above polymer is less than 100,000, there is a possibility that the improved hydrous soil cannot be granulated. As a result of the study by the present inventors, the hydrous soil generated in the Kanto region may not be granulated when the weight average molecular weight of the polymer is small, specifically, when it is less than 100,000, It has been found that the larger the weight average molecular weight, the smaller the amount of the polymer required for granulation. Further, as a result of further study by the present inventors, if the amount of the polymer used is equal, the larger the weight-average molecular weight of the polymer is, the more improved the hydrous soil, that is, the solidified product of the hydrous soil is industrial waste. It was found that the particles could be made finer (the particle size could be reduced) within a range that did not conform to the provisions of the product.

In the present invention, the weight average molecular weight of the above polymer is not particularly limited as long as it is larger than 100,000, but when it exceeds 20,000,000, it increases when the above polymer is mixed with hydrous soil. A viscous effect may be caused to make it impossible to mix the two uniformly, and it is difficult to produce the polymer. For this reason, the upper limit of the weight average molecular weight of the polymer is not particularly limited, but is preferably substantially 20,000,000 or less.

The above-mentioned polymer may be used as an aqueous solution or an emulsion, but from the viewpoint of handleability and mixing properties, it is more preferable to use the above-mentioned polymer as a powder by drying and pulverizing as necessary. More preferred. In addition, the drying method and the pulverizing method of the polymer are not particularly limited.

When the above polymer is used as a powder (particle), the particle diameter of the polymer is preferably in the range of 0.01 mm to 2 mm, more preferably in the range of 0.02 mm to 1 mm.
If the particle size of the polymer exceeds 2 mm, the amount of the polymer required to make the solidified product finer must be increased, which increases the cost, which is not preferable. On the other hand, when the particle size of the polymer is less than 0.01 mm, dust is easily generated when the polymer is handled, and the polymer is easily absorbed by moisture. Accordingly, workability is reduced, and when added to hydrous soil, flour is generated. For this reason, in order to finely solidify the solid obtained by improving the hydrous soil, the amount of use must be increased, which increases the cost, which is not preferable.

The amount of the above polymer to be used per 100 parts by weight of hydrous soil is preferably in the range of 0.01 part by weight to 5 parts by weight,
The content is more preferably in the range of 0.02 parts by weight to 1 part by weight. If the amount of the polymer is less than 0.01 part by weight, it is not preferable because the solidified product of the hydrous soil cannot be finely divided. Further, even when the amount of the polymer used is more than 5 parts by weight, the effect is almost the same as when the polymer is used within the above range. Accordingly, an excessively used polymer is wasted, which is not preferable. When the polymer is used in the form of an aqueous solution, the amount of the polymer used indicates the amount (pure content) of the polymer in the aqueous solution.

As described above, the improver for hydrous soil according to the present invention contains a water-soluble polymer having a cationic group. Next, an improvement method for improving water-containing soil using the improver having the above-described configuration will be described below.

In the improvement method according to the present invention, by mixing the above-mentioned improver (that is, the above-mentioned polymer) with the hydrous soil, the soil can be transported as an improved soil by truck. It is possible to obtain a solidified material that can be walked on by a person, and more preferably a solidified material having sufficient strength and a predetermined particle diameter, which is finely divided into particles. As a mixer used when mixing the hydrous soil and the above-mentioned improver, a device capable of stirring and mixing without kneading the mixture of both is preferable, and imparts a shearing force to the mixture of both. A device in which the shape of the stirring blade is formed in a rod shape, a fishing hook shape, or the like is preferable so that stirring can be performed. In other words, the shape of the stirring blade, which expands in the direction perpendicular to the moving direction of the mixture that is moved by stirring and mixing as much as possible, can suppress coarsening of the particle diameter due to kneading, and can be applied to the stirring blade and the inner wall of the device. Is preferable because the adhesion of the mixture can be prevented.

Examples of such an apparatus include a horizontal axis type mixer and a vertical axis type mixer. As the horizontal shaft type mixer, for example, a single-shaft and multi-shaft paddle-type mixer is preferable. As the vertical axis type mixer, for example, a pan mixer type mixer is preferable, a planetary type mixer is more preferable, and among these planetary type mixers, a soil mixer, a mortar mixer, and an Eirich mixer are further preferable. While mixing the hydrated soil and the improver using the above mixer, and using the shearing force generated by the stirring blade, the mixture has a particle size in the range of 0.1 mm to 50 mm, preferably in the range of 0.3 mm to 10 mm. It can be refined (granularly solidified) into particles inside. The method of mixing the hydrated soil with the improver is not particularly limited.

That is, in the method for improving hydrated soil according to the present invention, the improving agent for hydrated soil containing the polymer is mixed with the hydrated soil using a horizontal axis type mixer or a vertical axis type mixer. Improve the hydrous soil into granules.

Next, a hydraulic material is added to the obtained improved soil (granulated solidified material) and mixed. If a hydraulic substance is mixed before mixing the improver with the hydrous soil, the hydrous soil cannot be solidified granularly.

The hydraulic substance is not particularly limited as long as it hardens in water, and specific examples thereof include cement, quicklime, slaked lime, and the like.
Examples include gypsum, water glass, and mixtures thereof. Among the hydraulic materials exemplified above, cement and quicklime are more preferred.

As the above cement, various known cements can be employed. Specific examples of the cement include Portland cement such as ordinary Portland cement, early-strength Portland cement, and ultra-high-strength Portland cement; blast furnace cement; alumina cement; calcium cement; fly ash cement; There is no particular limitation.

The amount of the hydraulic substance to be used per 100 parts by weight of hydrous soil is preferably in the range of 1 part by weight to 20 parts by weight, more preferably in the range of 1 part by weight to 10 parts by weight. If the amount of the hydraulic substance used is less than 1 part by weight, the strength (described later) of the improved soil (granulated solidified material) may be insufficient. Further, even when the amount of the hydraulic substance used is more than 20 parts by weight, the effect is almost the same as when the hydraulic substance is used within the above range. Therefore, an excessively used hydraulic substance is wasted, which is not preferable.

The mixer used for mixing the hydraulic material with the improved soil (granulated solidified material) is not particularly limited, but an apparatus capable of stirring and mixing the two without kneading the mixture. Is preferred. In addition, when mixing using such a mixer, the shearing force is not applied as much as when mixing the above-mentioned hydrated soil and the improver, and a hydraulic substance is attached to the surface of the improved soil (granulated solidified material). It is preferable to stir so as to glaze. As a result, an improved soil (granulated solid) in which the hydraulic substance adheres almost uniformly to the surface of the improved soil (granulated solid) is obtained. In addition, the hydraulic substance may partially enter the inside of the improved soil (granular solidified material). Further, the method of mixing the improved soil (granular solidified material) and the hydraulic substance is not particularly limited.

That is, in the method for improving a hydrous soil according to the present invention, the hydrous soil improving agent containing the polymer is mixed with the hydrous soil to improve the hydrous soil into granules, and then the obtained granular solidified product is obtained. Add hydraulic substance.

The obtained improved soil (granulated solidified material) may be immediately backfilled. However, the hydraulic material is cured by leaving it at room temperature for about 3 to 7 days, so that it has a predetermined strength. Can be prepared.

The improved soil obtained as described above can be transported by truck, and is, for example, a solidified material improved so that a person can walk on it, more preferably a granular solidified material. Therefore, the improved soil does not correspond to industrial waste and can be reused. In particular, granular solids
Since it has a predetermined particle size and strength, it can be reused as a resource such as a substitute for sand without performing operations such as crushing and sieving. That is, in civil engineering work in which excavation holes need to be backfilled, backfill can be performed using the granular solidified material without separately preparing sand or the like. In addition, since the granular solidified material can improve water permeability when backfilled on the ground, it is possible to reuse the hydrous soil in a wider range. The particulate solidified material is, for example, a backfill material for backfilling a buried pipe or a structure, a barrier layer material as artificial sand, a vegetation base material for spraying a slope to process the slope, a soil improvement material , A water retaining material, a water permeable material, a water quality improving material, and the like. Thus, by implementing the improved method of the present invention, it is possible to reuse hydrous soil that is usually discarded as sludge, so that environmental conservation, resource saving, and life extension of the disposal place can be achieved, The disposal cost of the hydrated soil can be reduced.

Further, according to the above-mentioned method, since the hydraulic substance is added to the granular solidified product, the obtained solidified product does not disintegrate even when wet with water, and is in a state of being finely divided into particles. Can be maintained. Therefore, the solidified material does not collapse even when it is rained and can be piled up on a construction site, for example, and can be stored easily and at low cost.

[0046]

The present invention will be described in more detail with reference to the following Examples and Comparative Examples, but the present invention is not limited thereto. The weight average molecular weight (Mw) of the polymer as an improving agent was measured by gel permeation chromatography (GPC).

Example 1 Water containing soil was obtained by dewatering and pressing mud generated by excavation work using a mud shield construction method in the Kanto region. The water content of the water-containing soil was 62% by weight.

Next, a predetermined amount of the above-mentioned hydrated soil was charged into a planetary mixer (planetary mixer) provided with a hook-shaped hook-type stirring blade. Subsequently, while stirring the hydrous soil at 160 rpm, the powdery polymer (A) of methyl chloride quaternary salt of dimethylaminoethyl methacrylate as an improver according to the present invention was added to the hydrous soil as described above. It was added and mixed little by little so that the ratio to the hydrous soil was 0.3% by weight.

The weight average molecular weight (Mw) of the dimethylaminoethyl methacrylate methyl chloride quaternary salt polymer (A) was 4,000,000, and the particle diameter was in the range of 0.05 mm to 0.25 mm.

Next, while the obtained granules were stirred at 160 rpm, quicklime as a hydraulic substance was added little by little to the granules so that the ratio to the above-mentioned hydrous soil was 5% by weight. Mixed.

As a result, a finely divided product having a particle diameter in the range of 0.5 mm to 10 mm and an average particle diameter of 3 mm was obtained. afterwards,
The finely divided product was left (cured) at room temperature for 7 days to obtain a granular solidified product. The granular solidified product did not collapse even when poured into water and agitated, and kept in a state of being finely divided into particles. Table 1 shows the main solidification conditions, the particle size of the finely divided material, and the like.

Example 2 A predetermined amount of a water-containing soil having a water content of 105% obtained from the soil generated in Example 1 was charged into a twin-screw paddle type mixer. Subsequently, while stirring the hydrous soil at 45 rpm, the powdery polymer (B) of dimethylaminoethyl acrylate hydrochloride as an improver according to the present invention was added to the hydrous soil with respect to the hydrous soil. 0.2% by weight
Was added and mixed little by little so that

The dimethylaminoethyl acrylate hydrochloride polymer (B) has a weight average molecular weight (Mw) of 5,000,0
00, the particle size was in the range of 0.02 mm to 1 mm.

Next, while stirring the obtained granules at 45 rpm, Portland cement as a hydraulic substance was added little by little to the granules so that the ratio to the above-mentioned hydrous soil became 10% by weight. , Mixed.

As a result, a finely divided product having a particle diameter in the range of 0.3 mm to 20 mm and an average particle diameter of 4 mm was obtained. afterwards,
The finely divided product was left at room temperature for 7 days to obtain a granular solidified product. The granular solidified product did not collapse even when poured into water and agitated, and kept in a state of being finely divided into particles.
Table 1 shows the main solidification conditions, the particle size of the finely divided material, and the like.

Example 3 A predetermined amount of a water-containing soil having a water content of 105% and obtained from the soil generated in Example 1 was charged into an Eirich mixer. Subsequently, while stirring the water-containing soil at a container rotation speed of 15 rpm and a stirring blade rotation speed of 18 rpm, powdery dimethylaminoethyl methacrylate / methyl chloride 4 as a modifier according to the present invention was added to the water-containing soil. Grade salt / 2-acrylamido-2-methylpropanesulfonic acid / sodium salt copolymer (C) in the above-mentioned hydrous soil
It was added and mixed little by little so as to become 0.4% by weight.

The dimethylaminoethyl methacrylate / methyl chloride quaternary salt / 2-acrylamido-2-methylpropanesulfonic acid / sodium salt copolymer (C) in the above dimethylaminoethyl methacrylate / methyl chloride quaternary salt and 2-acrylamide- The molar ratio with 2-methylpropanesulfonic acid / sodium salt is 95/5, and dimethylaminoethyl methacrylate / methyl chloride quaternary salt / 2-acrylamido-2-methylpropanesulfonic acid / sodium salt copolymer (C) Weight average molecular weight (Mw)
Was 2,500,000, and the particle size was in the range of 0.05 mm to 0.25 mm.

Next, the obtained granules were placed in a container rotating speed of 15 r.
While stirring at 18 rpm with a stirring blade rotation speed of 18 rpm, slaked lime as a hydraulic substance was added to the granules little by little so that the ratio to the above-mentioned hydrous soil was 5% by weight.

As a result, a finely divided product having a particle diameter in the range of 0.5 mm to 20 mm and an average particle diameter of 4 mm was obtained. afterwards,
The finely divided product was left at room temperature for 7 days to obtain a granular solidified product. The granular solidified product did not collapse even when poured into water and agitated, and kept in a state of being finely divided into particles.
Table 1 shows the main solidification conditions, the particle size of the finely divided material, and the like.

Example 4 A predetermined amount of a water-containing soil having a water content of 62% obtained from the soil generated in Example 1 was charged into a soil mixer. Subsequently, while stirring the hydrous soil at 160 rpm, the hydrous soil was added to the hydrous soil in the form of a powder as an improver according to the present invention,
Dimethylaminoethyl methacrylate / methyl chloride quaternary salt / acrylamide copolymer (D) was added little by little so that the ratio to the above-mentioned hydrous soil was 0.2% by weight.

The above-mentioned dimethylaminoethyl methacrylate / methyl chloride quaternary salt / acrylamide copolymer (D) had dimethylaminoethyl methacrylate
The molar ratio of methyl chloride quaternary salt to acrylamide is
10/90, dimethylaminoethyl methacrylate
The weight average molecular weight (Mw) of the methyl chloride quaternary salt / acrylamide copolymer (D) is 6,000,000, and the particle diameter is 0.3.
It was in the range of 05mm to 0.25mm.

Next, while stirring the obtained granules at 160 rpm, gypsum as a hydraulic substance was added little by little to the granules so that the ratio to the above-mentioned hydrous soil was 10% by weight. Mixed.

As a result, a finely divided product having a particle diameter in the range of 0.3 mm to 10 mm and an average particle diameter of 2 mm was obtained. afterwards,
The finely divided product was left at room temperature for 7 days to obtain a granular solidified product. The granular solidified product did not collapse even when poured into water and agitated, and kept in a state of being finely divided into particles.
Table 1 shows the main solidification conditions, the particle size of the finely divided material, and the like.

[0064]

[Table 1]

[Comparative Example 1] A predetermined amount of a water-containing soil having a water content of 62%, which was obtained by dewatering and pressing the muddy water of Example 1, was charged into a soil mixer. Subsequently, while stirring the hydrous soil at 160 rpm, Portland cement as a hydraulic substance was added to the hydrous soil little by little so that the ratio with respect to the hydrous soil was 20% by weight. However, the water-containing soil solidified in a lump, and no granular material could be obtained. Table 2 shows the main solidification conditions. In addition, the above-mentioned hydrated soil solidified in a lump did not disintegrate even when it was poured into water and stirred.

[Comparative Example 2] A predetermined amount of a water-containing soil having a water content of 105%, which was obtained by dewatering and pressing the muddy water of Example 1, was charged into an Eirich mixer. Subsequently, the hydrated soil is transferred to a container rotating speed.
The polymer (A) of the methyl chloride quaternary salt of dimethylaminoethyl methacrylate was added to the hydrous soil while stirring at 15 rpm and a stirring blade rotation speed of 18 rpm so that the ratio to the hydrous soil was 0.3% by weight. Little by little,
Mixed.

As a result, a finely divided product having a particle diameter in the range of 0.5 mm to 20 mm and an average particle diameter of 4 mm was obtained. afterwards,
The finely divided product was left at room temperature for 7 days to obtain a granular solidified product. However, the granular solids collapsed when poured into water and stirred. Table 2 shows the main solidification conditions, the particle size of the finely divided material, and the like.

[0068]

[Table 2]

From the results shown in Table 1, it can be seen that the above-mentioned hydrous soil can be refined by implementing the improvement method according to the present invention. And it turns out that the granular solid obtained can be maintained in a state of being finely divided into particles without being collapsed even when it is poured into water and stirred. Also, from the results shown in Table 2, when the improvement method according to the present invention is not carried out, the above-mentioned hydrous soil cannot be granulated, or the obtained granulated solid is put into water and stirred. Then you can see that it collapses.

[0070]

As described above, the method for improving hydrous soil according to claim 1 of the present invention comprises mixing a hydrous soil improving agent containing a water-soluble polymer having a cationic group into the hydrous soil as described above. This is a method of adding a hydraulic substance to the obtained granular solid after improving the soil to a granular form.

According to the method for improving hydrous soil according to claim 2 of the present invention, as described above, a hydrous polymer containing a water-soluble polymer having a cationic group is prepared by using a horizontal axis type mixer or a vertical axis type mixer. By mixing a soil conditioner with hydrous soil,
This is a method for improving the hydrous soil into granules.

In the method for improving a hydrous soil according to claim 3 of the present invention, as described above, the water-soluble polymer is a monomer component containing an aminoalkyl (meth) acrylate and / or a quaternized product thereof. The method is at least one polymer selected from the group consisting of a polymer obtained by polymerization, a Hoffman decomposition product of polyacrylamide, a Mannich modified product of polyacrylamide, and polyvinylamine.

According to the above-mentioned method, the improved hydrous soil can be transported by truck, for example, a solidified product improved to a state where a person can walk on it, more preferably, a solid product having sufficient strength and Since it can be solidified into a fine particle having a predetermined particle size, the water-containing soil normally discarded as sludge can be effectively used as a resource such as a substitute for sand (reuse). It has the effect that it can be done. In addition, since the solidified material after improvement can be reused, it is possible to save the environment, save resources, extend the life of disposal sites, and reduce the disposal cost of hydrous soil. Play.

In addition, according to the method of the first aspect, since the hydraulic substance is added to the granular solidified product, the obtained solidified product does not disintegrate even when wet with water and is finely divided into particles. State can be maintained. Therefore, the solidified material does not collapse even when it is rained, and can be piled up on a construction site, for example, so that it can be stored easily and inexpensively.

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Claims (3)

[Claims] An aqueous soil improver containing a water-soluble polymer having a cationic group is mixed with an aqueous soil to improve the aqueous soil into granules, and then a hydraulic substance is added to the obtained granular solidified product. A method for improving a hydrous soil, characterized in that: 2. An aqueous soil improver containing a water-soluble polymer having a cationic group is mixed with a hydrous soil using a horizontal axis type mixer or a vertical axis type mixer, whereby the hydrous soil is granulated. A method for improving hydrous soil, comprising: 3. A polymer obtained by polymerizing a monomer component containing an aminoalkyl (meth) acrylate and / or a quaternized product thereof, a Hoffman decomposed product of polyacrylamide, and a Mannich of polyacrylamide. The method for improving hydrous soil according to claim 1 or 2, wherein the method is at least one polymer selected from the group consisting of a modified product and polyvinylamine.