JPS5874780A - Grouting technique - Google Patents

Abstract

PURPOSE:To improve and strengthen the ground according to its condition and soil condition, by conducting a mixing and injection stage of a self-hardening alkaline water glass-formulated liquid and a self-hardening acidic water glass- formulated liquid in combination with an injection stage of a self-hardening alkaline water glass-formulated liquid. CONSTITUTION:An injection stage of a flash setting grout having a gel time of 30sec or shorter obtd. by combining a self-hardening alkaline water glass-formulated liquid having a pH of pref. 9 or above with a self-hardening acidic water glass-formulated liquid having a pH of pref. 4 or below, is conducted in combination with an injection stage of said alkaline water glass-formulated liquid (a penetration grout). For example, a double wall tube is placed under the ground as shown by the figure. The self-hardening alkaline water glass- formulated liquid is fed through the outer tube thereof. The self-hardening acidic water glass-formulated liquid is fed through the inner tube. After the flash setting grout obtd. by combining both liquids is injected, the supply of the liquid through the inner tube is stopped and only the alkaline water glass-formulated liquid is fed through the outer tube.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a process in which the main material is an alkaline gelatinous Shiro water glass mixture, and an acidic water glass mixture that can gel itself is joined thereto to cause rapid solidification. This relates to a ground injection method comprising the steps of: and injecting the alkaline water glass mixture.

As described above, the present invention comprises an alkaline water glass compounded liquid having a pH of 9 or more and capable of gelling itself, and a liquid having a pH of 5 or less.
Particularly preferably, a self-hardening liquid having a pH of 4 or less is capable of rapidly solidifying the liquid glass mixture within 30 seconds, usually within a few seconds, when combined, and the strength of the rapidly solidified solid is excellent. Furthermore, this method focuses on the fact that this combined liquid maintains a stable and wide instantaneous setting region, and solidifies reliably even if the joining of the two liquids varies. In the present invention, instant connection is 30
It means that it gels within seconds.

The present applicant is currently applying for the following invention in his earlier application, Japanese Patent Application No. 164143/1983. This will cause rapid solidification if the reactant mixture or cement suspension is combined with the water glass mixture, which itself can gel, so a double injection pipe is used to inject the above-mentioned self-hardening water glass mixture from one pipe. The reactant mixture and cement suspension are intermittently combined from the other pipe, and the instant-setting combined liquid first fills the area around the injection pipe and rough areas of the ground to form a packer. After that, by injecting a water glass mixture with good permeability and a long gelation time, it is possible to infiltrate into a thin soil layer without deviating from the injection range.

The present invention is a further development of the prior invention in order to further improve the packer effect of this instant-setting combined liquid. That is, the above-mentioned prior invention requires conversion between instant setting grout and permeable grout, and when a suspension such as cement is used as a rapid setting reactant, instant setting suspension is generated at the injection tube discharge part. This tends to cause blistering, making it difficult to alternately inject instant setting grout and permeable grout.

In order to solve this problem and prevent clogging, it is possible to combine the solution-based reactant mixture, but on the other hand, the water glass contained in the combined liquid is not thin, resulting in a decrease in the strength of the instant setting grout. A tendency arises. This is because, in reality, the two liquids are usually combined at a ratio of 1:1 (volume ratio) due to the convenience of the injection operation, so that the water glass concentration of the combined liquid is halved.

That is, in order to make the packer effect effective, it is desirable that the strength of the compacted material serving as the packer is high, but this is difficult to achieve with the above method.

Furthermore, as mentioned above, the two liquids are usually joined at a ratio of 1:1, but due to variations in injection operations, it is practically difficult to maintain a constant ratio of 1:1, and considerable variations tend to occur.

In this case, if an aqueous solution of reactant containing salt or salt is used as the rapid setting liquid, it is possible to obtain an instant gelling time by maintaining an exact ratio of 1:1, but if this varies, instant setting will occur easily. It tends to deviate from the gelation time of That is, the instantaneous setting area due to variations in the ratio of both liquids becomes narrower. In this case, if the gelation time of the combined liquid of both liquids is longer than the instantaneous setting, the packer effect will not work effectively.

The present invention has solved the above problem, and based on the relationship between the gelation time and pH of water glass shown in Figure 1, water glass has P
Focusing on the fact that the kelization time is shortest in a region where H is around 8, it is preferable to use an alkaline region, preferably a pH of 9 or more, more preferably a pH of 9.5 or more, and most preferably a pH of 10.
Acidic,
By using a 1-hard acidic water glass compounded liquid having a PR of preferably 5 or less, more preferably a PH of 4 or less as a quick-setting compounded liquid, the consolidation strength of the combined liquid of both liquids can be increased, and the solidification strength of both liquids can be increased. The present invention was completed based on the discovery that a wide range of instantaneous bonding regions can be obtained even if the merging ratio varies.

The present invention will be explained in detail below using experimental examples.

Actually! -1 Table 1 shows the relationship between No. 3 water glass and PH (20°C) in a mixed solution of No. 3 water glass (specific gravity 1.4) and a commercially available 40% glyoxal aqueous solution (specific gravity 1.25).

Table-1 and PH relationship.

(II Experiment-2) IE containing potassium water glass that can gel itself (
The relationship between the formulation of liquid A) and the gelling time is shown in Table 2. (Experiment 3) The relationship between the formulation of the self-hardening acidic water glass mixture (liquid B) and the gelling time is shown in Table 3.

Table-3 Liquid B (self-hardening water glass compounded liquid) l (per KICC (
Experiment-4) Measure the unconfined compressive strength by injecting Yamasago KA liquid or B liquid,
Insert a double injection tube into the same mountain sand and insert A at the tip.
Strength of nine solid bodies obtained by joint injection of liquid and B liquid and A
Table 4 shows the gelation time and PH4i of the combined liquid of liquid and liquid B.
Shown below.

Table 4 (Experiment 5) For comparison, a self-hardening alkaline water glass mixture liquid was used as liquid A, and an acidic reactant aqueous solution was used as liquid B, and both liquids were mixed at 1:1.
1, and the gelation time and strength of the consolidated mountain sand are shown.
Table 5 (Experiment 6) The confluence ratio of the self-hardening alkaline water glass mixture and the self-hardening acidic water glass mixture was changed to tt and the mixture was 1! The gelation time of the solution and the PHoIII relationship are shown in Figure 2 and $13.
- Shown below.

In Figure 2, sh* and Bi[ are as follows. Compounded liquid 0B1 exhibiting 1J
A compounded liquid exhibiting a gelation time of 4XIOsec.

In addition, in FIG. 3, liquid A and liquid B are as follows.

Solution A: Same as in Figure 2.

B2 solution: 3% by weight of water sealed glass, acidic sulfuric acid (IJ), pH 2.2, gelling time 1.5
A compounded liquid exhibiting the Kari 04 formula.

(Experiment-7) For comparison, the relationship between the gelation time and PH of the combined liquid was investigated by changing the confluence ratio of the self-hardening alkaline water glass mixture and the acidic reactant aqueous solution. The results are shown in FIG. The merging ratio (volume ratio) of liquid A and liquid B is shown on the horizontal axis.

Here, liquid A and liquid B are as follows.

Solution A: A water glass reactant mixture containing a No. 3 hydraulic lath with a concentration of 35% by volume and a commercially available 40% glyoxal solution with a concentration of 5.87% by volume.

Solution B: Weighted % aqueous solution of NaH804/H20.

Incidentally, the general relationship between the pH of the combined liquid of water glass and the acidic reactant aqueous solution and the gelation time is shown in FIG. 1 for reference.

The above experiment revealed the following.

■ Experiment 7 shows that even if you try to shorten the self-hardening alkaline water glass mixture by combining it with an acidic liquid, the instant setting range is very narrow, and if the mixing ratio of λ liquid and B liquid varies, it will easily deviate from the instant setting range. Resulting in.

Also, from Experiment 5, the strength of the solidified body due to the combined liquid is much lower than that of liquid A alone.

■ Experiment 4 shows that when a self-hardening acidic water glass mixture is combined with a self-hardening alkaline water glass mixture, the strength of the consolidated body from this combined liquid is significantly higher than the average value of both grouts; It is not only possible to prevent the strength from decreasing as compared to the consolidation strength obtained by using only the hard alkaline water glass mixture, but it is also possible to obtain even greater strength.

■ From Experiment 6, when a self-hardening acidic water glass mixture was used as a rapid setting agent in a self-hardening alkaline water glass mixture,
The instant setting area becomes very wide, and even if the ratio of discharge amounts of liquid A and liquid B varies, the packer effect by the instant setting grout can be surely expected.

(2) According to Table 4 of Experiment 4, P)l of the self-hardening alkaline water glass mixture is preferably 9 or more, preferably 9.5 or more, and most preferably 10 or more.

Why,? ) The water glass compounded liquid in the Fi alkaline region has a pH of
This is because the gelation time is longer and the permeability is better, and when it is combined with the acidic water glass mixture, it gels rapidly and gels within a few seconds, producing an excellent packer effect.

As the pH of the alkaline water glass mixture approaches neutrality, even if it merges with the acidic water glass mixture, it becomes difficult to achieve instantaneous gelation within a few seconds, and the strength of the solidified body created by the combined liquid increases significantly. decreases to

From Experiment-1, No. 3 water glass (specific gravity: 1.40) and commercially available No. 4
When using 0% glyoxal (ratio: 1[:1.25)] When using commercially available 40% glyoxal as a reactant for an alkaline mixture, α = 0.27 or less is usually used and other reactants are used as accelerators. Even when used in combination as a liquid, it can be blended in such a way that the pH value of the liquid mixture is 9.0 or higher, or 9.5 or higher.

■ From Experiment 1, as shown in Figures 2 and 3, when mineral acid is used as the acid for self-hardening acidic water glass and when acid salt is used, the results are shown in Figures 2 and 3. It turned out that there was a difference in the situation in the instant connection area.

FIG. 2 shows an example in which sulfuric acid was used as the mineral acid, and FIG. 3 shows an example in which sodium hydrogen sulfate was used as the acid salt.

According to this, it can be seen that the latter has a wider instantaneous bonding area than the former. This tendency also occurs when an acid salt is used in combination with a mineral acid, and it is therefore clear that it is better to use an acid salt as an active ingredient than to prepare an acidic water glass mixture solution using a mineral acid alone.

As the injection tube in the present invention, any multilayered tube such as a double tube, a triple tube, or a tube in which several tubes are inserted in parallel can be used. A typical implementation method of the present invention is as shown in FIG. 5, but in this case, a check valve may be provided at the tip of the inner tube or further between the inner tube and the outer tube. , After installing a double pipe in the ground as shown in Figure 5 (a) Φ) (C), a self-hardening alkaline water glass mixture is sent from the outer pipe and a self-hardening acidic water glass mixture is sent from the inner pipe. After the liquids are combined and the instant setting grout is injected, the liquid supply through the inner pipe is stopped, and only the non-alkaline water glass mixture is installed from the outer pipe, thereby effectively improving the ground. Figure 5(d) (
e) is a diagram in which the same process was repeated by changing the stage. Figure 6 shows the permeable grout being infiltrated from the tip of the inner tube after installing the double pipe and injecting the instant setting grout. This figure shows a case where permeable grout is injected from the lower outlet.

In the figure, l is the outer pipe, 2 is the inner pipe, 3 is the metal crown, 4 is the inner pipe discharge hole, 4' is the check valve, 1 is the outer pipe line, ■ is the inner pipe line, and A is the multiple pipe. , B is the upper discharge hole, C is the lower discharge hole, D
E indicates the solidified area of the instant-setting grout, and E represents the penetrating solidified area of the solution-type grout.

As mentioned above, the present invention provides a grout with a short gelation time,
A major feature is that long grout can be applied depending on the ground and soil conditions. For example, when using an alternating layer of ground consisting of clay and sand layers, the clay layer is treated with only instant-setting grout, while the sand layer is treated with permeable grout. It is possible to inject it instead of grout, or it is also possible to inject instant setting grout and permeable grout in a layered manner. In any case, the present invention requires a step of jointly injecting a self-hardening alkaline water glass mixture and a self-hardening acidic water glass mixture, and a step of injecting a self-hardening alkaline water glass mixture. .

The self-hardening alkaline water glass compounded liquid in the present invention is
A mixed solution that can be gelled in an alkaline region with a pH of 9 or higher, which is obtained by mixing water glass with an arbitrary reactant, and the gelation time is 5.
Within hours - Usually within 100 minutes, a blended solution is used.

This type of compounded solution contains esters that produce acids when hydrolyzed in the presence of acids, salts, or alkalis in an aqueous water glass solution, such as triacemone, polyalcohols such as ethylene glycol diacetate, and butylene glycol diacetate. It can be obtained by adding esters, dicarbonate alkyl esters, inorganic acid esters such as ethylene carbonate, or organic substances such as glyoxal.

This compounded liquid is usually obtained by mixing water glass and a reactant in a mixer, but in some cases, it can also be obtained by feeding the water glass aqueous solution and the reactant aqueous solution separately and merging them halfway. The self-hardening and hostile water glass mixture is usually obtained by adding water glass to an acidic liquid and preferably has a pH of 5 or less. Of course, other organic acids or organic reactants that act as acids by being hydrolyzed in the presence of an alkali can also be used. Father, in this acidic water glass mixture, arbitrary salts and metal balides, including bicarbonate, carbonate phosphate, etc., may be added as a gelling agent or stabilizer. . Moreover, this acidic water glass compounded liquid is a self-hardening compounded liquid which gels in one hour to several hours. Further, it is desirable that the content of the commercially available water glass aqueous solution in this compounded solution is 10% by weight or more. As a result, it is possible to combine with the self-hardening alkaline water glass mixture to obtain a stable instant setting range and sufficient strength.

The water glass used in the present invention has a molar ratio of 15 to 5.0.
Any liquid water glass can be used.Example 1 Two electric pipes were installed at a predetermined depth in the ground consisting of alternating layers of sand and fine sand in the Tokyo area using the method shown in Figure 5. Tested.

[Composition]

The composition of liquids A and B was as described in FIG. 3.

First, liquid B is mixed from the inner tube and liquid A is mixed from the outer tube at l=1, and the combined liquid with a pH of 1O15 and a Gellich time of 2 seconds is injected.The mixture of liquid B is interrupted and liquid A is injected. After injecting only the liquid, I ascended the stage and repeated the process.

A subsequent excavation investigation revealed that the area around the injection pipe and the interface between the alternating layers was filled with grout that took a short gelling time, and the grout that took a long gelling time penetrated between the soil particles and solidified homogeneously. I found out what happened.

Example 2 An experiment was conducted using the method shown in Figure 7 in the ground consisting of alternating layers of clay and fine sand in the Tokyo area. The combination of A and B liquids is 3rd.
The formulation mentioned in the figure was used.

In the cohesive soil layer, liquid A was injected from the outer tube and liquid B from the inner tube, and in the thin layer, after the combined liquid of A and B was injected, liquid A was injected, and the stage was raised and repeated.・ Investigation of the excavation revealed that grout with a short gelation time was filled in the boundary between the injection pipe and alternate layers, as well as the clay layer, while in the fine sand layer, grout with a long gelation time penetrated between soil particles. It was found that it was solidified homogeneously.

[Brief explanation of the drawing]

Figure 1 shows the pH of the confluence of water glass and acidic reactant aqueous solution.
2 is a graph showing a general relationship between
Figures 5 to 4 are graphs showing the relationship between the gelation time and PH of the combined liquid by changing the combined ratio of the non-alkaline water glass mixture and the water glass aqueous solution, and Figures 5 (a) and (
b), (C), (d), and (e) are representative process diagrams of the construction method of the present invention, and FIGS. 6 and 7 respectively show other process diagrams of the construction method of the present invention. 1...Outer pipe, 2...Inner pipe, 3...Metal crown, 4...Inner pipe discharge hole, 4'...Check valve, I...Outer pipe conduit, ■. ...Inner pipe conduit, A...Multiple pipe, B...
Upper discharge hole, C: lower discharge hole, D: solidified portion of instant setting grout, E: penetration solidified region of solution type grout. Patent applicant: Reinforced Soil Engineering Co., Ltd. M Den2me E150 #901i! II 3?
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x 5゜Reiseihimu (reverse ratio)'! J3 eyes j2 course! #, 1M1l pure 1゜An
3 δ # Nazu 〃+Ryohigo (Vat tile) ′$9＠

Claims (1)

[Scope of Claims] (1) Using an alkaline water glass mixture liquid that can gel itself and an acidic water glass mixture liquid that can gel itself, the alkaline water glass mixture liquid and the acidic water glass mixture liquid are combined to form a gel. A ground injection method characterized in that a step of injecting grout whose curing time is within 30 seconds and a step of injecting the alkaline water glass mixture are used together. (2. In the construction method described in claim 1, a double injection pipe is used to inject the alkaline water glass mixed liquid and the acidic water glass mixed liquid into the two pipe lines constructed in the double pipe, respectively. A ground injection method characterized by using in combination a step of injecting a grout whose gelation time is within 30 seconds by sending a liquid and injecting both of the above-mentioned solutions together, and a step of injecting only the above-mentioned alkaline water glass mixed solution. (3) In the construction method according to claim 1, the pH of the hostile water glass mixture is adjusted to 9 or more, and the pH of the hostile water glass mixture is adjusted to 5 or less. Injection method. (4) A ground injection method according to claim 1, characterized in that the acidic water glass mixture is prepared with water glass and acid salt as essential components.