JPS6315882A - Non-alkali chemical grouting method - Google Patents

Abstract

PURPOSE:To facilitate the adjustment of gel time in a non-alkali chemical grouting method in which water glass and a gelling agent such as sulfuric acid are used, by injecting into the ground a mixture of an aqueous solution of a gelling agent with a mixed solution prepared from a water-glass solution and a powder of a hardly soluble substance. CONSTITUTION:In a chemical grouting method in which water glass is used as principal ingredient, and a gelling agent selected from among sulfuric acid, sodium bisulfate, and a mixture thereof is added thereto to cause to gel in a neutral or acid region, a grout obtained by the following method is grouted into the ground: The grout is prepared by mixing a liquid A which comprises a mixed solution prepared from a water-glass solution and a powder of a hardly soluble substance satisfying at the same time the conditions I and II mentioned below with a liquid B which comprises an aqueous solution of a gelling agent selected from among sulfuric acid, sodium bisulfate, and a mixture thereof. The above-mentioned conditions are as follows: (I) it undergoes a neutralization reaction with an acid gradually: (II) it undergoes no solidifying reaction with water glass (most preferable), or it takes at least 8hr to solidify after mixing with water glass.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a water glass solution-type injection chemical and an injection construction method for the purpose of strengthening and water-stopping ground with relatively good permeability such as sandy soil. .

More specifically, the present invention uses water glass as the main material and adds sulfuric acid (11□5O4), sodium bisulfate (Na1 (SO+)) or a mixture thereof as a gelling agent to form water glass in the mid-rod to acidic region. This invention relates to a non-alkaline injection drug solution that is gelatinized.

<Prior art> In the conventional chemical injection method using water glass as the main material, generally, a water glass solution is mixed with an acid or salt solution or a water glass solution. It lowers the value and causes it to form in the ground.

As shown in FIG. 1, conventional methods can be roughly divided into alkaline methods that cause gelation in an alkaline region and non-alkaline methods that utilize gelation in a neutral to acidic region.

Among these, non-alkaline systems used for gelation in a neutral to acidic region are classified into direct methods and indirect methods.

The direct method is to add and mix a liquid acid or a silk combination of an aqueous solution of acids and salts to water glass, and calculate the p and ll values of the mixture (the final pu value is indicated at the same time as mixing; hereinafter, this is referred to as a fixed pH value). The method is to directly obtain the injected chemical solution with the desired solidification time (hereinafter referred to as gel time) and gelation in the ground. In contrast, the indirect method involves dissolving excess acid or a combination of acids and salts in a water glass solution.
Add and mix to adjust the pH value of the mixture to a strongly acidic (pi11~
In this method, a silica sol with a concentration of 2 or less) is prepared, and an alkali agent or the like is added to this silica sol to gel it in the neutral to acidic range of I'113-8.

In the direct method, a strong acid, such as sulfuric acid, is added to a solution of acids and salts or a highly alkaline water glass solution;
Strong acid to be added (11 value (fixed As can be seen from the relationship diagram between Ti1l value) and gel tie 11,
The slope of the curve is gentle! , pH around 7 to 8 (Keltai 13 for about 1 minute or less) l) When using an injected chemical solution (J, even if the mixing area of the acidic liquid material used in the actual injection site is slightly different from the designed mixing area) The pH value and gel time of the injectable drug solution do not show large fluctuations.Therefore, it has been put into practical use as an instant-setting injectable drug solution (gel time of 1 to 2 minutes or more 8B, direct method) that allows easy control of gel time.

However, 1) When the 11 value is below about 5 to 6, the pH value of the injected drug solution will fluctuate sharply due to the error in the acidic liquid material (gelling agent) addition IJ (φV), and the result will be Due to the large fluctuations and the difficulty of control at the injection site, injection drug solutions with a pH value of about 5 to 6 or less, that is, a gel time of 1 to 2 minutes or more, by the direct method have been considered unsuitable for practical use.

<Problems to be Solved by the Invention> The present invention aims to provide a non-alkaline direct chemical injection method that overcomes the above-mentioned drawbacks. A: Human medicinal solution according to the present invention has an r)11 value belonging to the neutral to acidic region of around 4 to 6, and has a value of -1-1 for 1 to 2 minutes or more.
Preferably, the drug solution is directly injected with a Kel time of 10 minutes or less.

<Means for Solving the Problems> In order to solve the above problems, the present invention uses a poorly soluble powder agent that satisfies specific conditions.

That is, the non-alkaline injection drug 'lI'2 of the present invention is mainly made of hydrolase, and a gelling agent selected from sulfuric acid, sodium bisulfate, and mixtures thereof is added to form a medium-M to acid f.
In the chemical injection method for gelling in one area, a mixture of a hydraulic lath solution and a powder of a poorly soluble substance that satisfies both conditions [T] and [I1] below is used as the Δ liquid, and sulfuric acid, sodium bisulfate, and these This is a non-alkaline chemical liquid injection EE method characterized by using an aqueous solution of a gelling agent selected from the mixture of (1) as the 3 liquid and injecting a mixture of both An and An liquids into the ground.

Condition [I] is to gradually cause a neutralization reaction with an acid. The conditions [If] are that no solidification reaction occurs with water glass (hereinafter referred to as invention A) and that the solidification time (gel time) after mixing with water glass is 8 hours or more (hereinafter referred to as invention B). .

In the present invention, It2So or Na11SO is present in a mixture of an alkaline water glass solution and a powder of a poorly soluble substance that satisfies both conditions [I] and [I1] in -IZ.

When an aqueous solution (acidic gelling agent) is added, the following two reactions occur continuously.

(First stage) Both liquid water glass and gelling agent (II2SO4 or N
a1ls'4 aqueous solution) undergoes a neutralization reaction at the same time (instantaneously) as it is mixed. This reaction is called a first-order reaction, the substance that causes this first-order reaction is called a first-order reactant, and the pH value obtained by this first-order reaction is called a fixed pH value.

(Second Stage) Following the primary reaction of the first stage, a neutralization reaction gradually occurs between the residual acid content not used in the reaction with water glass and the slightly soluble powder of the present invention. This reaction is called a secondary reaction, the substance that causes this secondary reaction is called a secondary reactant, and the pH value obtained by this secondary reaction is called a fluctuating phi value.

In the present invention, water glass is gelled in a neutral to acidic region by continuously causing the primary and secondary reactions described in -.

As a result, gelation can be practically achieved in a loosely set region with a gel time of 1 to 2 minutes or more, preferably 10 minutes or less (Pl (about 4 to 6)).

<Function> The non-alkaline chemical solution produced by the conventional direct method of combining water glass and a liquid acidic reactant utilizes only the primary reaction referred to in this specification, and the gel time is reduced to 1 to 2 minutes. It was impossible to set it to higher than that.

In other words, when gelling is performed in a neutral to acidic region around 1114-6, the factors that determine the gel time are (Npo value (ii) water glass concentration (SjO□ content) (iii)
Of these, (11) water glass concentration (SjO2-containing material) can be arbitrarily and easily selected, and (iii) liquid temperature (ambient temperature) is measured before injection. be able to.

Therefore, using a non-alkaline chemical solution by the direct method, pl(
It can be said that the factor that made it difficult to implement the injection method of gelling in the acidic region of around 4 to 6 was the problem of pH value management.

According to the present invention, the liquid A is a mixture of a water glass solution and a secondary reactant (poorly soluble powder) that satisfies the specific conditions [I] and [TI], and the liquid B is a sulfuric acid aqueous solution, a sodium bisulfate solution, etc. Using an aqueous solution or a mixed aqueous solution of sulfuric acid and sodium bisulfate, mixing both AB and A, the first reaction (fixed pl1 value)
By using a combination of and a secondary reaction (variable pH value),
The problem of pH value management (gel time adjustment) can be solved.

<Example> The secondary reactant that causes the secondary reaction must satisfy the first condition, that is, it must be a sparingly soluble powder that gradually causes a neutralization reaction with the acid.

Substances that meet the first condition include those that exhibit neutrality and alkalinity when dissolved in water; substances that exhibit neutrality include calcium carbonate, pure water magnesium carbonate, and alkaline agents. There are weak alkaline agents such as magnesium hydroxide and salt-grade magnesium carbonate, and strong alkaline agents such as calcium hydroxide and cement.

Next, even if the secondary reactant of the present invention is a substance that satisfies the first condition, the second condition, that is, the solidification reaction with water glass (
Most preferred is a substance that does not cause gelling reaction (gelation reaction) (invention A).

In addition, water glass builds up a consolidation pressure of 10 degrees very slowly, making it completely unpractical as a medicinal solution, and the consolidation time exceeds 8 hours (equivalent to working hours per day). 1- can be sufficiently used in the construction method of the present invention (Invention B).

That is, in the case of the direct method of the present invention, the greatest feature is that in actual construction, the A solution after mixing with the water glass solution is stably maintained for a long time without solidifying.

Therefore, as a substance that satisfies the second condition, a secondary reactant (A invention) that does not cause any solidification reaction with water glass, or a secondary reactant (B invention) that causes a very slow solidification reaction with water glass. invention). In particular, in the case of invention B, it is desirable that after mixing with water glass, it is as hard as possible, merges with liquid B (gelling agent), and injects into the ground.

Substances that satisfy the first condition of the present invention include calcium carbonate, pure magnesium carbonate (A invention), weak alkali
(Invention B) was announced.

On the other hand, strong alkaline substances such as hydroxide and calcium oxide] cement cause a strong caking reaction with water glass and gelatinize within at least 1 to 2 hours, so the secondary reactant of the present invention more excluded.

-1] Even if substances other than calcium carbonate, magnesium carbonate, and magnesium hydroxide are used under the conditions of the present invention [
Any substance that satisfies I and condition [I(]) can be used as the secondary reactant of the present invention.

Next, the basic idea of the present invention will be explained with reference to FIG.

Figure 2 is a schematic diagram showing the change in the PI1 value of the injected drug solution with respect to the elapsed time when a certain amount of gelling agent is added as the B solution to the mixed solution of the egg water glass solution and the secondary reactant as the A solution. Yes The horizontal axis is the elapsed time after AB liquid mixing, and the vertical axis is the pH of the injected drug solution.
Show value.

As shown in Fig. 2, the PAL value of the injectable drug solution according to the present invention is linear due to the action of the primary reactant from the time when both A and B are mixed (indicated by O in the figure) to the point indicated by ■ in the figure. It shows a change. Due to the reaction with the primary reactant (primary reaction, indicated by (1) in the figure) that causes this linear pH value ratio change, the pH value of both AB and AB liquids is approximately pH 1 to 3 (the fixed pH value of the conventional technology). )become.

According to the present invention, the gelling agent that was not used in the primary reaction and the secondary reactant that satisfies the conditions (1) and (n) of the present invention are gradually intermediated along the curve from ■ to ■. A sum reaction, ie, a secondary reaction occurs, and the pH value gradually increases -I-. This state of pH value is called a fluctuating pH value.・For this reason, the p and H values at the time of consolidation of the present invention are within the neutral to acidic curve in Figure 1 in the case of only the conventional first reaction, that is, if the gel time is the same, the p and H values during consolidation with the method of the present invention are When this is done, the pH value shows a higher value, and it is possible to solidify on the neutral side.

In addition, since a secondary reactant is used, the pH value can rise slightly even after solidification, so it has excellent features such as being able to gel in a near-neutral region even though it is a long gel tie 11. are doing.

Conventional water glass (Liquid A) and sulfuric acid or sodium bisulfate solution (B
The method of the present invention in which the secondary reactant is mixed in the liquid A compared to the injection chemical solution in which the liquid A is mixed with the secondary reactant = j) Adjustment of gel time becomes very easy.

ji) The pH value of the solidified material can approach the neutral region.

It has the characteristics of

The object of the present invention is to carry out the primary and secondary reactions described in -1- continuously by a direct method, thereby making it easy to adjust the gel time.

In addition, we invented a completely different injection method from the present invention, that is, an injection method using calcium carbonate and magnesium carbonate powders, which are part of the secondary reactants used in the present invention, in an indirect method (silica sol system). We have previously filed a patent application (Japanese Patent Application No. F53-66310).

This earlier application is a silica sol-based chemical solution produced by an indirect method, and water glass is treated with a strong acid using a special device to produce a PI31-2 chemical solution.
The following strongly acidic silica sol will be made, but since the pot life (time from making to gelling) is short,
It will be manufactured on-site and will be highly concentrated (containing 5in2).
The disadvantage is that it is difficult to create a silica sol solution with a constant pH value.

In addition, since a silica sol liquid is used as the main ingredient (liquid A), the indirect method has drawbacks such as requiring a silica sol production device and requiring one more step than the direct method.

In the previous application, the silica sol liquid was used as liquid A, and a gelling agent (B) was added to this.
The gel time is basically adjusted by increasing or decreasing calcium carbonate, etc. as a liquid.

However, in reality, since the PR value of the silica sol solution fluctuates, it is necessary to increase or decrease the amount of gelling agent depending on the pH value, which has the disadvantage that it becomes more difficult to adjust the gel time.

On the other hand, the secondary reactant (calcium carbonate, etc.) of the present invention is added in a certain amount to the water glass solution (Liquid A), and the gel time is adjusted by adding the gelling agent sulfuric acid or sodium bisulfate solution (Liquid B). It is adjusted by increasing or decreasing.

In other words, the secondary reactant used in the present invention is not used to adjust the gel time, but is a substance used to facilitate the adjustment of the gel time, and the technical idea is completely different from that of the previous application. The effects (characteristics) will also be different. Now, as methods for preparing the non-alkaline chemical solution according to the present invention, there are two methods: (1) mixing the secondary reactant together with the water glass solution in advance in a mixing tank to form liquid A, and (2) mixing the water glass solution with the liquid. The secondary reactants are prepared separately and mixed into the water glass solution (A
The present invention can be carried out using either method.

However, when carrying out the method (1) above using the secondary reactant of invention B, it is desirable to inject it as soon as possible after preparation.

In any case, the mixing of the water glass solution and the secondary reactant is
It is sufficient as long as it is not mixed with the gelling agent (liquid B).

The method of the present invention is a non-alkaline chemical injection method characterized by injecting the thus prepared mixture of AB and AB into the ground.

The water glass used in the present invention is not particularly limited, but water glass with a molar ratio of 3 or more -1 is preferable since it is gelatinized in a neutral to acidic region as a non-alkaline chemical solution.

EXAMPLES Below, Examples and Comparative Examples of the present invention will be described.

The water glass used in the following examples and comparative examples was Sin□
Water glass containing 24.1% and 7.5% Na2O was used.

As the sulfuric acid, a diluted sulfuric acid aqueous solution prepared by diluting industrial sulfuric acid (72.8%) four times with water was used. Sodium bisulfate aqueous solution is 27
Add water to 0g of Na1lSO, H2O and boil at 600 c.
The aqueous solution prepared in step c was used.

In addition, reagents were used for calcium carbonate (precipitated), basic magnesium carbonate, magnesium hydroxide, and calcium hydroxide as poorly soluble powders, and Portland cement was used as the cement.

Dog experiment-1 In this experiment, cement (comparative example-1) was used as a slightly soluble powder.
) and calcium carbonate (Example-1).

1 g of cement or calcium carbonate, 3 cc of sulfuric acid and 4 cc of water
The relationship between the elapsed time and pH value (fluctuating pH value) when added to 97 cc of acidic aqueous solution (pH - 0, 45) is shown in the third table.
Shown in the figure.

In addition, magnesium hydroxide, basic magnesium carbonate,
Similar results to those shown in FIG. 3 were obtained when calcium hydroxide was used.

From this, it can be seen that all of the above-mentioned substances gradually undergo a neutralization reaction with the acid and satisfy the condition ['lF of the present invention.

Tai Experiment-2 In Experiment-1, a poorly soluble powder that satisfies the conditions of the present invention [I1]
Table 1 shows the results of whether the condition [I11 was satisfied or not.

As a result, calcium carbonate does not cause a caking reaction with water glass, which corresponds to invention A of the present invention, and basic magnesium carbonate and magnesium hydroxide cause a very slow reaction with water glass, but the caking time is 8. Therefore, the present invention can be fully implemented and falls under Invention B.

On the other hand, cement and calcium hydroxide are excluded from the present invention because they react strongly with water glass and solidify in a short time.

Husband, Experiment-3 Example-2 using calcium carbonate of the present invention (A invention)
21.5 cc of sulfuric acid for liquid A of the formulation (100 cc)
In the case of adding water and adding 100 cc of gelling agent solution B (Example-9), and in the case of adding water to 23.2 cc of sulfuric acid and adding 1
When adding 00 cc of gelling agent B solution (Example-1
FIG. 4 shows the relationship between the elapsed time after mixing AB liquid 0) and the pH value.

In addition, 100 cc of gelling agent solution B, which is made by adding water to 46 cc of sodium bisulfate, was added to solution A of the formulation (100 cc) of Example-6 using basic calcium carbonate of the present invention (invention B). For 100 cc of solution A in the case where magnesium hydroxide was added (Example-11-) and when magnesium hydroxide was used (Example-8), 100 cc of water was added to 46.7 cc of sodium bisulfate for gelation. When adding liquid B of the agent (Example-
12) The relationship between the elapsed time after mixing the AB liquid and the pH value is shown in the fifth column.
As shown in the figure.

In addition, as a gelling agent in (Example-9) and (Example-10), sodium bisulfate was used instead of sulfuric acid, and (Example-10) was used as a gelling agent.
Similar results were obtained when sulfuric acid was used instead of sodium sulfate in +1 of 11) and (Example-12).

From this, both the A invention and the B invention of the present invention show that the secondary anti-J, F,;
Add sulfuric acid and bisulfuric acid sorter solution (gelling agent) to the combined solution (solution A)
When you add liquid B, all of the gelling agent and water glass are added during mixing (instantly)! t reacts (first reaction), and then the remaining gelling agent and the slightly soluble secondary reactant gradually react (
2nd anti-IE,) and gradually increase the r)11 value to 1-■. It is easy to understand that the so-called fluctuating r)11 value should be raised and solidified.

Note that the primary reaction and secondary reaction of the present invention are carried out continuously (actually, the reactions start at the same time, but since the water glass completes the reaction instantly, they can be separated in this way). I]1 at the boundary between the first-order reaction and the second-order reaction (values are approximate values).

Also, from Figures 4 and 5, Δ invention and [3 shots 11j1
It can be seen that both show almost the same trends.

Harm D41 Example-2 using calcium carbonate of the present invention (A invention)
and B for liquid A of the formulation (100CC) of Example-3.
FIG. 6 shows the relationship between the amount of addition and the amount of water added when sulfuric acid is added as a liquid in Example-13 and Example-14.

As a comparative example, a case where sulfuric acid was added to liquid A (40 cc of water glass and 60 cc of water) of only hydraulic lath without adding any secondary reactant was shown as Comparative Example 4 in FIG.

Furthermore, even when sodium bisulfate was used as the gelling agent in Examples 13 and 14 instead of sulfuric acid, the same results as in FIG. 6 were obtained.

From FIG. 6, it can be seen that in the conventional comparative example 4, the gel time changes greatly when the amount of gelling agent is 1 minute or more, but in the present invention, the gel time is preferably 1 to 2 minutes or more. It can be seen that the adjustment can be easily made within 10 minutes.

When comparing Example-13 and Example-14 in 1), 2
It can be seen that the gel time can be more easily adjusted by adding a larger amount of the next reactant.

Moreover, the relationship between the pH value and gel tie 11 during gelation in Example-13 and Example-14 is shown in FIG.

Experiment 1-5 - Salt of the present invention (+'! invention)], (magnesium carbonate (
Example-6) and magnesilla hydroxide 11 (Example-8)
Example 15 and Example 16 show the relationship between the amount added and the gel tights when sodium bisulfate was added as a gelling agent to liquid A, as Example-15 and Example-16.

For comparison, a case in which a secondary reactant was added and sodium bisulfate was added to liquid A (40 cc of water glass and 71 ml of water glass) containing only water glass is also shown as Comparative Example 5 in FIG.

Further, even when sulfuric acid was used instead of sodium bisulfate as the gelling agent in Examples 15 and 16, the same results as shown in FIG. 7 were obtained.

As shown in Fig. 7, in Comparative Example 5, the gel time changes greatly due to the presence of a very small amount of gelling agent, but compared to the invention in 4 (1).
3 invention) Similar to the invention (Fig. 6), Gertai l\]~2
It can be seen that the adjustment can be easily made within 10 minutes, preferably within 10 minutes.

As described in 1- below, in the present invention, when a sulfuric acid (or sodium bisulfate) solution is added as a solution B to solution A, which is a water glass solution and a TAt-soluble powder as a secondary reactant, the conventional primary reaction can be carried out. Compared to the injection method, the secondary reaction occurs continuously, and as a result, it is very easy to adjust the gel time. Very useful as a medicinal solution.

(Hereafter, margin)

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram for explaining the outline of a chemical solution injected into the ground using water glass. FIG. 2 is a schematic diagram drawn to facilitate understanding of the basic idea of the present invention. FIG. 3 is a graph showing elapsed time and changes in PU value (variable PH value) when a secondary reactant is added to acid (sulfuric acid). 4 and 5 are graphs showing the elapsed time and changes in pH value when a gelling agent (sulfuric acid) is added to a mixed solution of 1.2 secondary reactant and water glass. FIGS. 6 and 7 are graphs showing changes in the gel time of the injected drug solution corresponding to changes in the amount of gelling agent added in Examples and Comparative Examples. FIG. 8 is a graph showing the relationship between the pH value and gel time of the injected drug solution in Examples. 1 (Figure F')' 1 f La 1 leap length 2 1171 C+) Sai et al 1 child lfl 20 24
2g/Tl”c’/ja 47>Q l (k;
fi 'A) off 1 figure lj
4H P continuation amendment (method) 1. Indication of the case Patent Application No. 158846 of 1985 2. Name of the invention Non-alkaline chemical injection method 3. Person making the amendment Relationship with the case Patent applicant 4. Order for amendment Date: September 30, 1985 5. The application to be amended, and a duplicate copy of the application, and Specification 6. Contents of the amendment (1) We will submit the application and the duplicate copy of the application, which have been printed with a printing machine and clearly stamped. (2) We will submit a detailed statement (full text, with no changes to the content) clearly printed using a printing machine. (more than) −2=

Claims (2)

[Claims] (1) In the chemical injection method, which uses water glass as the main material and adds a gelling agent selected from sulfuric acid, sodium bisulfate, and a mixture thereof to gel it in a neutral to acidic range, the water glass solution and the following are used. A liquid mixture of powders of poorly soluble substances that satisfies both conditions [I] and [II] is liquid A, liquid B is an aqueous solution of a gelling agent selected from sulfuric acid, sodium bisulfate, and mixtures thereof, AB A non-alkaline chemical injection method characterized by injecting a mixture of both solutions into the ground. Condition [I] Gradual neutralization reaction with acid. Condition [II] No caking reaction with water glass. (2) In the chemical injection method, which uses water glass as the main material and adds a gelling agent selected from sulfuric acid, sodium bisulfate, and a mixture thereof to gel in a neutral to acidic range, the water glass solution and the following are used. A liquid mixture of powders of poorly soluble substances that satisfies both conditions [I] and [II] is liquid A, liquid B is an aqueous solution of a gelling agent selected from sulfuric acid, sodium bisulfate, and mixtures thereof, AB A non-alkaline chemical injection method characterized by injecting a mixture of both solutions into the ground. Condition [I] Gradual neutralization reaction with acid. Condition [II] The solidification time after mixing with water glass is 8 hours or more.