JPH0747734B2 - Solidifying agent for hydrous soil - Google Patents

Description

The present invention relates to a solidifying agent for hydrous soil.

[Prior Art] The water-containing soil generated during civil engineering works is highly fluid, making it difficult to carry out by ordinary trucks or dumps. Conventionally, as a solidifying agent for solidifying and stabilizing this water-containing soil and facilitating the carrying-out work,
A solidifying agent for hydrous soil consisting of a mixture of a water-soluble polymer and gypsum or a mixture of a water-soluble polymer and a water-soluble polyvalent metal compound which has a high viscosity in an aqueous solution such as (meth) acrylamide (co) polymer Are known (for example, Japanese Patent Application Laid-Open No. 1-81886 or Japanese Patent Application Laid-Open No. 63-44097) filed by the present applicant.

[Problems to be Solved by the Invention] However, since it is inevitable to proceed with the civil engineering work under the constraints of the construction period, it is said that the water-containing soil discharged from the construction site is solidified in the shortest possible time. Strong demand,
In addition, even in a high water content soil where the water content ratio of the water content soil exceeds 100%, the solidification agent can facilitate the unloading work, and the hydrated soil after solidification during the unloading work does not collapse due to rainfall, and the unloading work can be continued. In addition, there is a demand that after being carried out, even if it is treated as waste, it will not collapse and will be stable for a long period of time.
Conventional solidifying agents have been required to further improve performance in many aspects.

[Means for Solving Problems] The inventors of the present invention have earnestly studied to obtain a solidifying agent that rapidly solidifies a high-moisture content soil so that it can be immediately carried out and that maintains a solidification property for a long period after solidification. As a result, the present invention has been achieved.

That is, the present invention relates to a synthetic water-soluble polymer compound (a) having a water thickening property and a powder of a fluorosilicate mineral (b).
And a synthetic water-soluble polymer compound (a) having a water-thickening property, a powder of a fluorosilicate mineral (b) and a surfactant (c). is there.

Examples of the synthetic water-soluble polymer compound having a water thickening property in the present invention include polyvinyl alcohol, polyvinylpyrrolidone, polycarboxylic acids (polyacrylic acid, etc.) and salts thereof (alkali salts such as sodium and potassium ( Alkali metal salts such as sodium and potassium, water-soluble metal salts in which part or all of the carboxyl groups are replaced by alkaline earth metals such as calcium, magnesium and aluminum, ammonium salts, etc.), polyethylene oxide, according to the applicant's application JP-A-1
(Meth) acrylamide (Co) described in Japanese Patent Publication No. 81886
Examples thereof include polymers. Of these, preferred are (meth) acrylamide (co) polymers, polycarboxylic acids and salts thereof, and combinations of two or more of these.

In the present invention, the phyllosilicate (b) is not particularly limited and may be a naturally occurring phyllosilicate or an artificially produced phyllosilicate. Specific examples of the phyllosilicate (b) include montmorillonite group minerals such as sodium montmorillonite, calcium montmorillonite, sodium bentonite, calcium bentonite, acid clay, activated clay, organic bentonite, phlogopite, biotite, muscovite. , Mica group minerals such as sericite, illite, and sigrite, kaolinite, halloysite, decite, nacrite, kibushi clay, frog eye clay, kaolin, choline clay, calcined clay, kaolin minerals such as sigrite, talc, Minerals mainly composed of hydrous magnesium silicate such as talc, stylus stone, soap stone, kamitalc, pyrophyllite, wax stone clay,
Examples thereof include wax or the like, natural or artificial zeolites such as mordenite and clinoptilolite, and allophane. Among these, preferable ones are those exemplified in and and combinations of two or more thereof. Phyllosilicates (b) in the present invention surrounds its structure Si ⁴⁺ and one tetrahedral layer consisting of O ^2- surrounding the Si ⁴⁺ and Al ³⁺ or Mg ^22+, such as Fe ²⁺ and these
The unit is a state in which one octahedron layer composed of OH ⁻ or O ^{2 −} is bonded as a unit, and these are stacked between the 1: 1 type (two-layer structure) phyllosilicate and two tetrahedral layers. It is distinguished by a 2: 1 structure (three-layer structure) of phyllosilicate in which these octahedral layers are sandwiched and bonded to each other as a unit. Preferred in the present invention are phyllosilicates having a 2: 1 structure (three-layer structure). Further, the shape of the phyllosilicate (b) in the present invention is preferably powdery for blending as a component of the solidifying agent, and its particle size is not particularly limited, but it is usually a particle size that passes through a 16-mesh sieve, The particle size is preferably 100 mesh.

Examples of the surfactant (c) in the present invention include:
Amine salt-type cationic surfactants (dihydroxyethylstearylamine, salts of amines such as 2-heptadecenyl-hydroxyethylimidazoline), quaternary ammonium salt-type cationic surfactants (lauryltrimethylammonium chloride, lauryldimethylbenzylammonium chloride) , Quaternary amines such as cetylpyridinium chloride, stearamidomethylpyridinium chloride), and the like;
Sodium soap (sodium laurate, sodium stearate, sodium oleate, etc.), higher alcohol sulfates (sodium lauryl sulfate, sodium cetyl sulfate, sodium stearyl sulfate, sodium oleyl sulfate, etc.), higher alkyl ether sulfates Salt (sodium lauryl ether sulfate), sulfated oil (funnel oil,
Low-sulfated olive oil, etc.), sulfated fatty acid esters (sulfated butyl oleate, etc.), sulfated olefins,
Alkylbenzene sulfonate, alkylnaphthalene sulfonate, paraffin sulfonate, phosphate ester salt (higher alcohol phosphate monoester disodium,
Anionic surfactants such as higher alcohol phosphate diester sodium) and sodium sulfosuccinate di-2-ethylhexyl ester; polyethylene glycol type nonionic surfactants (higher alcohol ethylene oxide adduct, alkylphenol ethylene oxide adduct, fatty acid ethylene oxide) Adduct, polyhydric alcohol fatty acid ester ethylene oxide adduct, higher alkylamine ethylene oxide adduct, fatty acid amide ethylene oxide adduct, ethylene oxide adduct of fats and oils, polypropylene glycol ethylene oxide adduct, etc.), polyhydric alcohol type nonion Surfactants (fatty acid esters of glycerol, fatty acid esters of pentaerythritol, fatty acid esters of sorbitol and sorbitan, Nonionic surfactants such as fatty acid esters of fatty acids, alkyl ethers of polyhydric alcohols, fatty acid amides of alkanolamines, etc .; amino acid-type amphoteric surfactants (sodium laurylaminopropionate, etc.), betaine-type amphoteric surfactants (lauryl) Dimethyl betaine, stearyl dimethyl betaine, lauryl dihydroxyethyl betaine, etc.), amphoteric surfactants such as sulfonic acid type amphoteric surfactants, phosphate ester type amphoteric surfactants; and a combination of two or more thereof. Among these, preferable ones are those exemplified in and and combinations of two or more thereof.

In the hydrous soil solidifying agent of the present invention, the weight ratio of the component (a) to the component (b) is usually 80:20 to 10:90, preferably 7
It is from 0:30 to 20:80. When the above-mentioned value of the component (a) is larger than 80, the flow of the hydrous soil tends to decrease in a short time, but the hydrous soil after solidification is the inner wall of the mixer, the stirring blades, and the carrier bed of the transport vehicle. There is a case to adhere to. When the above-mentioned value of the component (a) is less than 10, it may take time to solidify or the solidification strength may decrease depending on the water content of the hydrous soil and the soil quality.

In the present invention, it is preferable to use the component (c) together for the purpose of improving the dispersion of the component (a) and the component (b) in the water-containing soil. In particular, for a high water content soil having a water content ratio of more than 100%, by using the component (c) together to improve the dispersibility of the solidifying agent, the solidifying time is further shortened and the solidifying strength is further improved. (A) when the component (c) is used in combination
The weight ratio of the component (c) to the total of the component and the component (b) is usually 1: 0.001 to 1: 0.3, preferably 1: 0.005 to 0.1.
Further, when the above-mentioned value of the component (c) is larger than 0.3, the effect of dispersing the soil particles in the water-containing soil becomes contradictory and becomes stronger, especially for a high water-containing soil having a water content ratio of more than 100%. It may take time to solidify.

When using the solidifying agent of the present invention, an optional component having the ability to solidify other water-containing soil may be used in combination, if necessary. Examples of such optional components include cement, slaked lime, quick lime, gypsum, calcium carbonate, slag, fly ash, silicate minerals other than phyllosilicate, sodium silicate, and water-soluble silicates such as potassium silicate. , And super absorbent polymers.

As the water-containing soil to be solidified in the present invention, for example, excavated soil discharged from a civil engineering construction site such as a shield having a water content ratio of 30 to 100%, a factory, a sedimentation basin discharged from a water purification plant for water and sewage, etc. Examples include various sludges that include sludge or high-moisture soil with a water content ratio of more than 100%, such as sludge accumulated in rivers and ports, and that require solidification treatment and are subject to disposal.

The amount of the solidifying agent added to the water-containing soil of the present invention varies depending on the water content ratio of the target soil and the soil quality, and is not particularly limited, but is usually 0.1 to 50 kg / m ³ , and preferably 1 to 20 kg / m ³ . If the amount added is less than 0.1 kg / m ³ , it will take time to solidify,
The solidification strength decreases, and if it exceeds 50 kg / m ³ , the economic merit decreases.

The form of addition and mixing of the solidifying agent for the water-containing soil of the present invention is not particularly limited, and it is desirable to add and mix it in the form of a mixture containing the component (a), the component (b) and optionally the component (c), Even if the components (a), (b) and, if necessary, the components (c) are added and mixed in any order, the performance is not adversely affected. Further, the mixing method may be any method, for example, adding the solidifying agent of the present invention from the hopper of the mixer to the water-containing soil carried by the slurry pressure pump, after stirring and mixing with a mixer with stirring blades, a belt Examples include a method of carrying out by a conveyor. Further, the solidifying agent of the present invention may be added and mixed in the whole amount at once, or may be added and mixed in several times.

[Examples] Hereinafter, the present invention will be described with reference to Examples, but the present invention is not limited thereto.

Examples 1-4, Comparative Examples 1-2 In order to produce the solidifying agent used in Examples 1-4, Table-1
The components (a) and (b) in the present invention shown in Table 1 were mixed in a weight ratio of 50:50. In Examples 1 and 4, this was used as the solidifying agent of the present invention. In Examples 2 and 3, in contrast to this 1, the component (c) shown in Table 1 in pure content was 0.
The solidification agent of the present invention was obtained by mixing in a weight ratio of 05. In addition, in order to compare with the solidifying agent of the present invention, in Comparative Examples 1 and 2, Table-1
The solidifying agent shown in was used. In Comparative Example 2, the water-soluble polymer is first added to and mixed with the water-containing soil according to the contents described in JP-A-63-44097, and then the water-soluble polyvalent metal salt is added. Adopted the method.

These solidifying agents were added to each excavated soil with different water content discharged in the shield work, and then kneaded for 2 minutes to obtain solidified soil. The addition amount of the solidifying agent for Comparative Example 1, (a) and gypsum are each 1.5 kg / m ^3, Comparative Example 2, (a) a water soluble polyvalent metal salt are each 1.5 kg / m ^3, In other cases, the solidifying agent was 3.0 kg / m ³ . In order to confirm the solidified state of the soil, measurement of the time required for solidification (abbreviated as solidification speed), penetration test and underwater disintegration test were conducted.
The results shown in Table-2 were obtained.

The penetration test was performed by using the Viger needle device used for the cement setting test, and the penetration depth of the standard rod (diameter 10 mm) was measured on the solidified soil immediately after kneading. In the water disintegration test, a solidified soil immediately after kneading was molded into a cylinder with a diameter of 5 cm and a height of 10 cm, which was immersed in water to give about 50% of the total volume.
Expressed in days until% collapses.

In Table 2, the penetration degree is one measure showing the strength of the mechanical strength of solidification. If this value is 10 mm or less, it will not be deformed by vibration, floating will not occur, and normal truck unloading will be possible. By the way, the penetration of the hydrated soil used in the test is 40 mm when no solidifying agent is added, and this value is in the full state, that is, it is extremely soft, and the hydrated soil requires solidification treatment. Means

In Table 2, since the solidification speed of Comparative Example 2 was divided and the polymer and the water-soluble polyvalent metal salt were added, the time until solidification required for each was added and displayed.

Note) Polymer 1: Polyacrylamide (molecular weight 6 million) Polymer 2: Acrylamide-sodium acrylate copolymer (molar ratio 60:40, molecular weight 18 million) Phyllosilicate 1: Sodium montmorillonite (100 mesh 95% powder) ) Phyllosilicate 2: Sericite (200 mesh 94% pass powder) Phyllosilicate 3: Kaolinic acid (200 mesh 99% pass powder) Phyllosilicate 4: Activated clay / talc = 1/1 (weight ratio) Mixture (200 mesh 98% powder) Surfactant 1: Polyoxyethylene lauryl ether sodium sulfate (anion) Surfactant 2: Lanolin ethyl sulfate fatty acid aminopropylethyldimethylammonium (cation) Surfactant 3: Polyoxy Ethylene nonyl phenyl ether Ethylene oxide 10 mol adduct (nonionic) Examples 5-10, Comparative Examples 3-5 As the component (a) in the present invention, an acrylamide-sodium acrylate copolymer (molar non-60: 40, molecular weight 1800)
10,000) and (b) as components, Examples 5 to 7 and Comparative Example 3
~ 4, sodium bentonite (200 mesh 9
0% passing powder), in Examples 8-10 and Comparative Example 5, calcium bentonite (200 mesh 90% passing powder) was used, and the blending ratio of the component (a) and the component (b) was changed variously. The solidifying agent of the present invention was obtained.

Using these solidifying agents of the present invention, solidification performance was confirmed for excavated soil in a shield construction with a water content of 80%. As for the evaluation, the solidification speed was measured, the penetration test and the water disintegration test were conducted in the same manner as in Example 1, and the results shown in Table 3 were obtained.

The addition amount was 6.0 kg / m ^{3 in} all cases.

Examples 11 to 13 and Comparative Examples 6 to 7 As the component (a) in the present invention, an acrylamide-sodium acrylate copolymer (molar ratio 60:40, molecular weight 180
As a component (b), calcium bentonite (2
00 mesh 90% powder), using a funnel oil (anionic surfactant) as the (c) component, and the weight ratio of the (a) component and the (b) component was 50:50,
The solidifying agent of the present invention was obtained by variously changing the compounding ratio of the component (c) in terms of pure component with respect to the total of the components (a) and (b).

Using these solidifying agents of the present invention, water is added to the excavated soil in the shield construction with a water content of 80% to obtain a water content of 130%.
The solidification performance was confirmed for the simulated highly hydrous soil prepared as above. For the evaluation, the solidification speed was measured, the penetration test and the water disintegration test were carried out in the same manner as in Example 1, and the results shown in Table 4 were obtained. The addition amount was 10.0 kg / m ^{3 in} all cases.

As is clear from the test results of Table-2, Table-3, and Table-4, by using the solidifying agent of the present invention, a (meth) acrylamide (co) polymer and gypsum were used in combination, or various water-soluble agents were used. It was found that the workability was remarkably improved by solidifying the highly water-containing soil in an extremely short time, as compared with the solidification method in which the water-soluble polymer compound and the water-soluble polyvalent metal salt were used in combination. Furthermore, if the solidifying agent of the present invention is used, the water disintegration property of the water-containing soil is good similarly to the conventional solidification method, and it is also excellent in resistance to fluidization and re-collapse of the solidified soil due to rainfall or the like. found.

[Effects of the Invention] The solidifying agent of the present invention has the following effects.

(1) By using the solidifying agent of the present invention, extremely short time can be obtained for water-containing soil with a water content ratio of less than 100% and high water content soil with a water content ratio of more than 100%, which is discharged in ordinary civil engineering works (shielding work, etc.). Moreover, it is possible to obtain a strong solidified soil, and in comparison with the conventional solidification method, it is very effective in terms of solidification speed and disintegration in water. Further, the solidifying agent of the present invention, compared with the solidifying agent of the prior art, at the same addition amount, the solidifying speed is significantly improved, and the soil after solidifying shows an extremely low penetration value, and should be in a strong state. You can In particular, even in a high water content soil having a water content ratio of more than 100%, it can be solidified in a short time and is not easily affected by the water content ratio.

(2) The solidified soil using the solidifying agent of the present invention can maintain a stable solidified property for a long period of time without being destroyed by rainfall or the like.

(3) It is a highly safe solidifying agent.

The solidifying agent of the present invention is a highly safe water-soluble polymer and mainly a naturally occurring phyllosilicate mineral and, if necessary,
It can be said that it is extremely safe against contamination of groundwater and its effects on the human body because it uses a highly safe surfactant that is widely used in the life industry field.

In this way, the solidifying agent of the present invention solidifies the hydrous soil strongly in an extremely short time, so that the construction period can be shortened more than before, and the high hydrous soil that has consumed a large amount of the solidifying agent up to now has been solidified. Even with respect to, it has become possible to cope with the economical addition amount. Because of the above effects, the solidifying agent of the present invention is useful, for example, for the treatment of excavated residual soil in urban civil engineering, for which the generation amount is increasing in the future.

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Claims (5)

[Claims] 1. A solidifying agent for water-containing soil, comprising a synthetic water-soluble polymer compound (a) having a water thickening property and a powder (b) of a fluorosilicate mineral. 2. A solidifying agent for water-containing soil, comprising a synthetic water-soluble polymer compound (a) having a water thickening property, a powder (b) of a fluorosilicate mineral and a surfactant. 3. A highly water-soluble synthetic compound (a) selected from the group consisting of-(meth) acrylamide (co) polymers, polycarboxylic acids and alkali metal salts or ammonium salts of polycarboxylic acids. The solidifying agent according to claim 1 or 2, which is a molecular compound. 4. The phyllosilicate mineral (b) is selected from the group consisting of montmorillonite group minerals, mica group minerals, pyrophyllite, pyrophyllite clay and pyrophyllite, and has a 2: 1 type crystal structure ( A solidifying agent according to any one of claims 1 to 3, which is a phyllosilicate mineral having a three-layer structure). 5. The surfactant (c) is an anionic surfactant and / or a nonionic surfactant.
4. The solidifying agent according to any one of 4.