DE1268554B - Soil consolidator - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY GERMAN WTWWS PATENTAMT Int. CL:

E02d

EDITORIAL

C07d German class: 84c-3/14 12O-11 Number: 1,268,554 File number: P 12 68 554.0-41 Registration date: October 14, 1965 Ausleeetetae: May 16, 1968

The invention relates to soil stabilizers in the form of a true aqueous solution containing an alkali silicate and contain a gelling agent, which bind soil particles together, so that the strength and bearing capacity the soils are increased and their water permeability is reduced, and which not only sands, but also stabilize soils containing silt.

In the present specification and claims, the term "water is needed" in the sense overall ίο that more than 5 grams of a compound in 100 g of water at 2O ⁰ C a real solution arise.

Since a soil containing silt contains very small particles, it is necessary to use a soil stabilizer, i.e. a Injection means for consolidating such a soil over a certain period of time in the state of a real solution of low viscosity is held and then quickly solidifies to one with the ground Form body of high strength. Furthermore, it is very desirable that the soil consolidator have the Above-mentioned property also in relation to a sand layer or mass, which consists of relatively large particles as it is easy for such an agent to penetrate the sand particles and as its application is easy.

There are several soil consolidators and methods of stabilizing various soils, including silty soils known. However, none of them are satisfactory for solidifying silty soils. In some the known processes are firstly sodium silicate and secondly gelling agents such as calcium chloride, Sodium aluminate, sodium bicarbonate, sodium silicofluoride, and cement and bentonite are used. As soon When these ingredients are mixed, they create a precipitate and the viscosity gradually begins to increase rise.

Therefore, they can hardly penetrate evenly into silty soils, and when the penetration is increased by lowering the amount of gelling agent, the gelling time becomes uncertain and no longer accurate controllable, and if the soil stabilizer gels at all, the strength of the gel is very low.

A method is also known in which a solution of organic compounds, such as chromium lignin, Acrylates and acrylamides, is used. Such a procedure can apply to any silty Soils are used, but has the disadvantage that, firstly, a complicated mixture including polymerization stimulator, accelerators and retarders are used, which are to a high degree stoichiometric Accuracy requires, secondly, the execution and control of the work are difficult, third-party equipment estiger

Applicant:

Sanyo Chemical Industry Company Limited,

Kyoto (Japan)

Representative:

Dr. W. Müller-Bore, Dipl.-Ing. H. Gralfs
and Dr. G. Manitz, patent attorneys,
3300 Braunschweig, Am Bürgerpark 8

Named as inventor:
Shoji Nishimura, Kyoto;
Makoto Tsuruoka, Hirakata;
Waichi Kadoya, Kyoto-fu (Japan)

Claimed priority:

Japan October 21, 1964 (59 813),
of December 22, 1964 (72 667),
of January 7, 1965 (865),
dated January 30, 1965 (5211),
of March 16, 1965 (15 202),
dated April 14, 1965 (22 037)

First, the material is expensive; and fourth, because of its organic nature, it is poor in durability.

Soil stabilizers which, according to US Pat. No. 2,968,572, are made from sodium silicate and a lower alkyl amide should be characterized by low viscosity fluctuations and a defined gel time, but suffer from the defect that not only a large amount of a gelling agent or lower Alkylaniids is required, but the gelling time is too long even when using large amounts of gelling agent is. If a metal salt is added to remedy this deficiency, a precipitate is formed at the same time, and the viscosity increases continuously, so that the material is hardly used to stabilize silty soils can be.

The soil stabilizer disclosed in U.S. Patent 3,012,405 is an emulsion which is relatively contains large particles and can therefore hardly be used for silty soils.

Soil stabilizers are also known which, in addition to waterglass, contain esters of organic carboxylic acids with ge

809 549S55

3 4

saturated alcohols such as ethyl acetate or isopropylene and do not increase the viscosity. It became solid acetate, or with unsaturated alcohols, such as vinyl, that especially water-soluble lac-

acetate, as a gelling agent for water glass. tine and ethylene carbonate, propylene carbonate or GIy-

In contrast to the composite carbonate according to the invention, i.e. typical alkylene carbonic acid esters,

However, these known soil compositions are suitable.

stabilizer not soluble in water. In addition, the linear piolactone and dimethylpropiolactone, γ-lactones such as carboxylic acid esters contained in the compositions known as examples of lactones / ^ - lactones such as β-Ρτο- are difficult to hydrolyze, which is why γ-butyrolactone, γ-valerolactone and γ-caprolactone, only a small proportion of the added ester <5-lactones such as <5-valerolactone, δ-gluconolactone and is actually effective, so that an excessively large io <5-caprolactone, ε-lactones such as ε-caprolactone, and Mi amount of the same are required is. This usually has the consequence that two or more of these lactones have exceeded their maximum solubility. Among these lactones, y-butyro are therefore unstable dispersions, which given lactone and ε-caprolactone are most suitable,
in case an emulsifier has to be added, and none can form, depending on the proper solutions. These dispersions penetrate the desired gel time, vary within wide limits, but only with difficulty, if at all, in extremely small areas. However, favorable results are obtained when soils are divided, such as silty. 0.5 to 10 percent by weight of the total composition

A further disadvantage is that, since this tongue of the present invention is applied, known carboxylic acid esters slowly hydrolyzed. The soil consolidators of the present invention are the viscosity of the water glass is constantly changing, generally by mixing commercially available, before the final sufficient solidification chem water glass, a gelling agent and the need occurs. For this reason, too, the known amount of water is retained.

Soil stabilizers are difficult to break into small-sized, silty areas. It has also been found that there are advantages

containing soils, as the viscosity on the one hand increases too much if a water-soluble, inorganic salt is added

increases and on the other hand the final solidification to 35 lent to a composition of an alkali metal

takes place late and the finally achieved strength is given mei-silicate, a gelling agent and water,

at least is too low. firstly because the error in the setting time of the soil

Another disadvantage arises from the fact that, secondly, because the strength of the strengthens is reduced

Use of the known carboxylic acid esters of the gels produced increases and thirdly because the gel time

solid ground is fairly permeable to water. 3 ° is shortened. Although it is also by application

The known unsaturated vinyl esters have that of a larger amount of a gelling agent or one The disadvantage of a low solubility in water and an alkali metal silicate is possible to increase the gel time Hydrolysis rate under alkaline abbreviations, deficiencies arise as a result of the visual conditions, which are always present with water glass. Because of the increase in viscosity and the stability of the composition low solubility is the resulting mixture decreases with 35 tongue. In addition, the gelling agent is more expensive Water glass not homogeneous, the penetration in than any inorganic salt, and the use finely divided soils are insufficient and the gel time of a larger amount thereof is uneconomical. the not even. Because of the high hydrolysis amount of the salt addition in the present invention speed increases the viscosity of the water glass can depend on the concentration of the Bolaufend so that for this reason too, the solidifying agent, the concentration and type of gelling penetration is made more difficult in finely divided soils. by means of and the desired gel time. In

The aim of the invention is therefore an improved soil - in practice, however, the gel time can be increased by adding

Solidifying agent, which is not only sands, but also less than 5 percent by weight of the inorganic

silty soils are stabilized and adjusted via a salt.

Desired and precisely determined time a real solution 45 Illustrative examples of the inorganic salts,

remains with low viscosity and then gels quickly, which must be water-soluble, are halides

thus has a defined gel time. (Sodium chloride, potassium chloride, ammonium chloride,

The soil consolidator according to the invention in the form of calcium chloride, zinc chloride, etc.), aluminates (Na-

a real aqueous solution contains an alkali silicate triuminate, potassium aluminate, etc.), chlorates (Na-

and a gelling agent and is characterized by trium chlorate, potassium chlorate, etc.), perchlorates (Na-

net that in addition to sodium silicate or potassium silicate, trium perchlorate, ammonium perchlorate, etc.), carbon

and water at least one water-soluble lactonate (ammonium carbonate, sodium bicarbonate, ca-

and / or ethylene carbonate, propylene carbonate or lium bicarbonate, ammonium bicarbonate), bisulfates

Glycerine carbonate as a water-soluble gelling agent (sodium bisulfate, potassium bisulfate, ammonium bisulfate

holds. 55 etc.), sulphates (ammonium sulphate, sodium sulphate, ca-

For reasons of convenience, silicon sulfate, etc., is usually used, bisulfates (sodium bisulfite, sodium waterglass, which is customary in potassium, which is a molar bisulfite, ammonium bisulfite, etc.), silicon fluorides (ratio of alkali metal to silicon dioxide of 1: 2, monosilicon fluoride, etc.), borates (sodium borate, kabis 4 or preferably 1: 3 to 4. In the pralium borate, ammonium borate, etc.), phosphates (Naxis, the commercially available water glass from 30 to 60 trium bisphosphate, potassium bisphosphate, ammonium bis-70 ⁰ Be is used, so that the alkali silicate 5 to 50 Phosphate, secondary sodium phosphate, secondary weight percent makes up the total composition

That in the soil consolidator according to the invention, etc.), pyrophosphate (sodium pyrophosphate, Kawendete Gelling agent must be water-soluble in order to also use lium pyrophosphate, ammonium pyrophosphate, etc.), penetrate silty soils. There must also be 65 pyrosulphates (sodium pyrosulphate, potassium pyrosulphate, react with the water glass after a desired time under ammonium pyrosulphate, etc.), bichromates (sodium rapidly forms a gel, may react with verichromate, potassium dichromate, ammonium dichromate mix with the water glass no precipitate, etc.), permanganates (potassium permanganate, Na-

trium permanganate, etc.) and mixtures of these salts.

Of these, inorganic salts having an oxidizing effect are particularly preferable because the oxidizing agent not only accelerates gelation, but also improves resistance, especially water resistance, by adding any organic matter (including the gelling agent) which has the properties of the solidified soil impaired, oxidized and decomposed. Oxidizing agents other than inorganic ones Salts such as hydrogen peroxide and peracetic acid are also effective.

It should be noted that the remainder of the composition is water, preferably in an amount of 35% up to 95.5 percent by weight, based on the total batch.

The process of stabilizing sands, silty and other soils is, according to this invention, that one soil consolidator, which from an alkali metal silicate, an ao gelling agent as defined above and water and optionally one water-soluble, inorganic salt, presses into the soil. The injection is usually given Pressure carried out. In general, a composition with a viscosity below 10 cP is used and a gel time of a few seconds to several hours.

Applying the present invention to crevices in rocks and large cavities in the subsurface, so the economy can be increased by adding bentonite, Sand, fly ash or cement can be increased.

The soil stabilizer according to the present invention is characterized in that it has the condition a true solution and low viscosity for a desired, adjustable time that it maintains a certain Has gelling time and only requires a relatively small amount of a gelling agent.

The following examples are intended to further illustrate the present invention, but it is not limited to them Examples limited. In each of the examples, the gel time means the time from the completion of the Mixing process of the components of a soil stabilizer until the point in time when the solution is no longer flows out when the mixing vessel is tipped over.

example 1

50 g of water glass (sodium silicate having a specific gravity of 1.404, a SiO ₂ : Na ₂ O ratio of about 3.1 and a total solids content of 38.2% by weight) was added to 90 g of an aqueous solution of a gelling agent, both of different ones Concentrations, and the initial viscosity, the pumping time (this is the time until the start of the viscosity change) and the gelation time at 20 ° C. The results are shown in Table 1. The formamide is listed as prior art for comparison.

Tabel

Water glass Gelling agent G water Initial viscosity Pumping time Gel time G G cP Minutes Minutes 50 y-butyrolactone 6th 84 2.4 9 11 50 y-butyrolactone 5 85 2.4 14th 16 50 y-butyrolactone 4th 86 2.3 23 25th 50 y-butyrolactone 3 87 2.3 51 54 50 Propylene carbonate 6th 84 2.5 14th 15th 50 Propylene carbonate 5 85 2.4 37 39 50 Propylene carbonate 4th 86 2.3 71 78 50 Propylene carbonate 3 87 2.3 120 160 50 Formamide 40 50 3.0 0.5 1 50 Formamide 35 55 3.0 12th 14th 50 Formamide 33 57 24 26th 50 Formamide 30th 60 2.8 46 50 50 Formamide 3.5 86.5 2.4 OC ' OC

Example 2

To show the effect of inorganic salts on gelation and pumping time, was added to some of the compositions of Example 1 Ig potassium permanganate added. The gelation and pumping times are in Table 2 shown.

Tabel

Water glass
G Gelling agent G salt G water
G At first
viscosity
cP Pumping time
Minutes Gel time
Minutes 50
50
50
50 y-butyrolactone
y-butyrolactone
Propylene carbonate
Propylene carbonate LO LO LO LO KMnO ₄
KMnO ₄ 1
1 87
86
87
86 2.3
2.4
2.3
2.4 51
29
120
18th 54
31
160
20th

When using potassium dichromate or ammonium sulfate in place of potassium permanganate were used obtained similar results.

Example 3

In this example, as shown in Table 3, the kinds of the gelling agent and the salt were varied.

A solution, which by adding 0 to Ig Salt and 27 g of water to 50 g of sodium silicate and an aqueous solution of the same volume (approximately 62 ml), which contained 3 to 5 g of a gelling agent and 0 to 1 g of Salt 5 were mixed together. The different Properties of the real solution thus obtained were determined at room temperature. The results are shown in Table 3.

Tabel

No. Gelling agent G To the
Silicate solution G To the
Gelling agent solution G At first
viscosity Pumping time Gel time added salt added salt cP Minutes Minutes 1 lo-propiolactone 3.0 _ _ _ _ 2.5 1.5 2.0 2 y-butyrolactone 3.5 - - - - 2.4 39 41 3 y-butyrolactone 3.5 - - NH ₄ HCO ₃ 0.8 2.5 31 33 4th y-butyrolactone 3.5 KMnO ₄ 1.0 NH ₄ HCO ₃ 0.8 2.5 16 18th 5 y-butyrolactone 3.0 KMnO ₄ 1.0 NaHCO ₃ 0.6 2.4 20th 22nd 6th y-butyrolactone 3.0 KMnO ₄ 1.0 (NH ₄ WSO ₄ 0.6 2.4 21 23 7th y-butyrolactone 3.0 KMnO ₄ 1.0 (NH ₄ ) ₂ HPO ₄ 0.6 2.4 21 23 8th y-butyrolactone 3.0 KMnO ₄ 1.0 NaCl 0.6 2.4 25th 27 9 y-butyrolactone 3.0 KMnO ₄ 1.0 NaAlO ₂ 0.6 2.5 22nd 24 10 y-butyrolactone 3.0 (NEQ ₂ Cr ₂ O ₇ 1.0 - - 2.4 28 30th 11 <5-valerolactone 3.5 - - - - 2.5 28 31 12th ε-caprolactone 4.0 - - - - 2.4 19th 20th 13th Ethylene carbonate 3.5 - - - - 2.4 11 13th 14th Ethylene carbonate 3.0 - - NaAlO ₂ 0.6 2.5 8th 10 15th Ethylene carbonate 3.0 - - (NH ₄ ) ₂ SO ₄ 0.6 2.5 6th 7.5 16 Ethylene carbonate 3.0 KMnO ₄ I ₅ O - - 2.5 2 3.5 17th Ethylene carbonate 3.0 KMnO ₄ 1.0 KCL 0.5 2.5 1.5 2 18th Propylene carbonate 3.5 - - - - 2.4 27 30th 19th Propylene carbonate 3.0 - - K ₂ SO ₄ 0.5 2.4 18th 21 20th Glycerine carbonate 3.5 - - - - 2.5 13th 15th

Example 4

Approximately 250 g of dried river sand with a particle size distribution as shown in Table 4 was placed in a mold 5 cm in diameter and 10 cm in height (which could be dismantled into three parts). You left a real one in it Solution made by mixing 50 g of sodium silicate, 4 g of γ-butyrolactone and 85 g of water slowly suck up from above until the sand no longer absorbed any solution. The gel time of the Solution took about 35 minutes at room temperature.

After one hour, the solidified soil was removed from the mold, placed in a polyethylene bag and kept in a moist state for 7 days. Then, a compressive strength with unimpeded lateral expansion and a permeability coefficient were determined. The former was 2.8 kgf / cm ² and the latter was 3.3 · ΙΟ " ⁶ cm / sec.

Table 4 Weight percent Grain size, mm Undersize, 100 2 90 1 44 0.5 10 0.2 0.5 0.1

Example5

Example 4 was repeated using a real solution of 50 g sodium silicate, 1 g potassium permanganate, 3 g γ-butyrolactone, 0.5 g ammonium sulfate and 85 g water (the gel time was 18 minutes at room temperature). The solidified mass of sand had a compressive strength with an unobstructed lateral extent of 3.2 kgf / cm ² and a permeability coefficient of 7.0 x 10 ^-5 cm / sec.

Example 6

Example 4 was repeated using a real solution obtained by mixing 50 g of sodium silicate, 4 g of e-caprolactone, 1 g of potassium permanganate, 1 g of sodium bicarbonate and 85 g of water. The compacted soil had a compressive strength with unimpeded lateral ^{expansion of 2.8 kgf / cm 2} and a permeability coefficient of 4.5 · ΙΟ " ³ cm / sec.

60

Example 7

Example 4 was made using a real solution obtained by mixing 50 g of sodium silicate, 3 g of propylene carbonate, 2.2 g of sodium chloride and 50 g of water were obtained repeatedly.

The solidified soil had a compressive strength with unimpeded lateral expansion of 2.5 kp / cm ² and

a permeability coefficient of 2.0 x 10 ^-5 cm / sec.

Example 8

A cylindrical shape 1 m in diameter and 2 m high (can be dismantled into six parts) was made with a Mountain sand with the particle size distribution shown in Table 5 filled and an injection tube 1.9 cm in diameter driven in its center to 10 cm from the bottom.

Table 5

IQ

■ grain size, μηι Undersize, percent by weight 840 .... "'.. 100 500 ^ 95 297 : 70. ,, 210 19th 105 5 74 0

401 of a real solution (with a gelation time of 40 minutes at 8 ^° C.) obtained by mixing well 120 kg of sodium silicate, 2.5 kg of potassium permanganate, 7.2 kg of γ-butyrolactone, 1.42 kg of ammonium bicarbonate and 208 kg of water were pressed into this mold under pressure through the injection tube. While the injection tube was pulled out in steps of 20 cm, 40 l of the solution were then injected into each position. The injection conditions were as follows:

Temperature of the solution ... 8 ⁰ C temperature of the mountain

sand 10 ° C

Injection speed .... 5 l / min.

Injection pressure 1.0 to 1.5 kgf / cm ²

Load 1.5 kp / cm ²

Twelve hours after the injection, the mold was taken apart, the solidification state of the mountain sand examined and made various tests. The sand was evenly shaped a column filling the lower part of the mold and in the shape of a cone in the upper part of the mold solidified. The properties of the sand mass before and after the injection are shown in Table 6.

Table 6

Sand volume (m ³ )

Apparent density (t / m ³ ) ....
Volume of the stabilized
Sand (m ³ )

Moisture content (%)

Pore ratio

Standard penetration test,

n-values (number / 30 cm) ..
Permeability coefficient

(cm / sec.)

Triaxial pressure test

Internal Friction Angle
(Degree)

Cohesion (kp / cm ² )

Before injection

1.531 1.41

16.1 0.74

33 ° 14 '0.25

After injection

1.72

1.011 26.8 0.69

1.1 × 10 ^-5

37 ° 57 '0.70

Example 9

A real solution consisting of 160 g sodium silicate, 3.25 kg potassium permanganate and 86.5 kg water, and a real solution consisting of 20 kg of γ-butyrolactone, 4.0 kg of ammonium sulfate and 176 kg Water was injected into the same mold as in Example 10 through a Y-pipe under pressure. the other conditions and injection methods were the same as in Example 8. Table 7 shows various ones Properties of the sand mass before and after injection.

Table 7

■ Before .. To Injection· injection Sand volume (m ³ ) '1.413 _ Apparent density (t / m ³ ) .... 1.45 1.73 Volume of the stabilized Sand (m ³ ) 0.669 Moisture content (%) 16.9 29.9 Pore ratio 1.08 0.94 Standard penetration test, n-values (number / 30 cm) .. 3 23 Permeability coefficient (cm / sec.) 1.3 x 10- ⁵ Triaxial pressure test Internal Friction Angle (Degree) 33 ° 14 ' 44 ° IT Cohesion (kp / cm ² ) 0.25 1.45

55

6o The following comparative examples 10 to 12 make the surprising advantages to be achieved according to the invention clear.

Example 10

Formamide according to US Pat. No. 2,968,572 was used as the gelling agent. A solution consisting of 50 g of sodium silicate, 10 g formamide and 75 g water, not solidified even 5 hours after mixing at 2O ⁰ C. The solution of the present patent with only 4 g of γ-butyrolactone instead of 10 g of formamide solidified 35 minutes after mixing.

Example 11

Example 4 was repeated using a solution of 50 g sodium silicate, 18 g formamide and 67 g water. The solidified sand mass had a compressive strength with unimpeded lateral expansion of 0.57 kp / cm ² , which is much lower than that of the sand mass in Example 4.

Example 12

50 g of sodium silicate of 30 ⁰ Be, 3.3 g ethyl acetate and 0.25 g Teepol (trade name of a surfactant, namely the sodium salt of a sulfated higher alcohol) were mixed to form an emulsion of 80 cP. When this emulsion was pressed into a silty soil under pressure, it did not penetrate the upper part

809 549/355

through although it was injected 40 minutes from the mixture, and after 50 minutes the flow stopped the emulsion completely. After 24 hours, the bottom was removed from the mold and the condition investigated its solidification. The floor was up to a height of 3.5 cm above the floor Form solidified evenly. The emulsion was uneven up to a height of 35 cm penetrated, and the ground had mostly not solidified, and further above was the ground at all not solidified.

Claims (3)

Patent claims: 1. Soil stabilizer in the form of a real aqueous solution containing an alkali silicate and a gelling agent contains, characterized in that it contains sodium silicate or potassium silicate cat and water at least one lactone and / or ethylene carbonate, propylene carbonate or glycerine carbonate contains as a water-soluble gelling agent. 2. Soil consolidator according to claim 1, characterized in that it consists of 5 to 50 percent by weight Alkali silicate, 0.5 to 10 percent by weight of at least one gelling agent and 0 to 5 percent by weight at least one water-soluble inorganic salt and 35 to 95.5 percent by weight water consists. 3. Soil consolidator according to claim 1 or 2, characterized in that it is used as a gelling agent Contains y-butyrolactone and / or ε-caprolactone. Considered publications:
German Patent No. 857,936;
German Auslegeschrifts No. 1069 878.1099 954. 809 549/355 5.68 © Bundesdruckerei Berlin