JPH0492013A - Ground grouting work - Google Patents

Abstract

PURPOSE:To improve the grouting work of ground by a method in which a reacting agent is added to a base liquid composed of water glass and a soluble reactant or water glass, a soluble alkali, and a soluble reactant, having a specific molar ratio to form a liquid having an adjustable gelling time, and the liquid is injected into the ground. CONSTITUTION:A base liquid is prepared from water glass and a soluble reactant as effective components as an alkaline liquid A of a gelling time of one hour or more, or from water glass, a water-soluble alkali, and a soluble reactant as effective components as an alkaline liquid B of a gelling time of one hour or more, having a molar ratio of 2.8 or below. A reacting agent is added to the base liquid to form an alkaline liquid having an adjusted gelling time. As the reacting agent, soluble inorganic salts are used, and as the water- soluble alkali of the liquid B, caustic alkalis are used. The alkaline grout liquid is injected into the ground, the gelling time of the grout can thus be easily adjusted.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a ground injection method for solidifying the ground by injecting a specific injection liquid into the ground. This article relates to a ground injection method that is easy and has excellent permeability.

[Conventional technology]

As an injection solution for ground consolidation, water glass grout is conventionally known, which is made by adding inorganic salts, organic salts, glyoxal, esters, cement, etc. to an aqueous water glass solution to form a gel.

In the above, when a water-soluble inorganic salt is used as the inorganic salt, when adjusting the gelation time, a slight difference in the amount of inorganic salt causes a significant change in the gelation time, or a slight difference in the amount of the inorganic salt. A phenomenon in which gelation did not occur occurred, and caking was therefore uncertain.

In addition, in the case of poorly soluble inorganic salts and cement, permeability is poor, and furthermore, in the above-mentioned organic examples, groundwater BOD and COD
There was a problem of increasing the

In the eight examples above, especially when using water-soluble inorganic salts,
If this gelation can be performed reliably and the gelation time can be easily adjusted, it is expected that an extremely useful injection solution will be produced.

Therefore, in order to realize this expectation, we mixed No. 3 water glass with NaCl, KCA, or alkaline earth metal salts in advance as Solution A, and prepared an aqueous solution of other reactants as Solution B. An injection method that combines liquids has been proposed. However, when NaCβ, KCA, or alkaline earth metal salts are mixed with No. 3 water glass, J-roids are rapidly formed in the mixed solution.
There is a problem in that the gelation time varies greatly depending on the elapsed time until the liquid is added, making it difficult to adjust the gelation time.

In addition, there is also known an injection method in which acidic water glass, which is formed by adding a strong acid to water glass, is used as the basic material2, and an rlkali agent is added to it. However, it has disadvantages such as the problem of handling soil and the difficulty in adjusting the gelling time.

[Problems that the invention attempts to solve 2. Water glass and reactant are mixed together. First, a mixture that can gel itself is used as the basic material 11, and a gelling agent is added to it.] In the horn method, the basic element O Δ always gels, so 1. It has the following advantages: 1) The gelling agent and the gelation time are adjusted; 1) the injection solution is always gelatinized; and 2) the solidification property in the ground is extremely good.

However, 1. The biggest drawback of this method is that after mixing the basic materials, the formation of intracranial roids is rapid and progresses. C is accelerated as the speed increases. Also, even if you try to adjust the gelling time by adding a gelling agent (liquid B) to this basic material (liquid A), the gelling time of the mixed liquids A and B will be the same as the basic 3I material (liquid A). The gelation time varies depending on the elapsed time from the time of blending until the time when the B solution is mixed with the A solution, and it is extremely difficult to obtain a predetermined gelation time.

In the actual field, the basic material, A liquid, is prepared [from step 2, ASB liquid is mixed and various operations are performed before injection, such as injection], and injections may be stopped or injected due to changes in the injection stage within the frame. Flushing due to a clogged pipe, temporary suspension of injection due to other problems, suspension of injection during lunch break, adjustment of the pump, etc., or adjustments to the composition of liquid B itself, or changes in the distance to each injection tube. Due to differences, etc., it takes more or less time to mix and inject liquid A and liquid B, and the time is not constant. Therefore, if we can find a method in which the gelation time is less likely to change regardless of the length of time that elapses between blending Part A and adding Part B, this injection method would be a method that would allow easy setting of the gelation time. This should be an excellent and highly practical construction method.

In addition, when construction becomes large-scale, a large amount of injection material is sometimes made, and then multiple pumps are used to send the liquid to many injection pipes, a gelling agent is added to each, the gelation time is adjusted, and the injection material is injected. However, the larger the amount of injection material produced at a time, the longer it takes from the start of injection until the injection material is used up, so regardless of the elapsed time, the gelation time If there are only a few hen-ayu, it becomes possible to use a more suitable injection method for large-scale treatment.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a ground injection method that allows easy adjustment of gelation time, has excellent permeability, and improves the drawbacks of the above-mentioned known techniques.

[Means for Solving the Problems J In order to achieve the above-mentioned object, according to the present invention, the following (
A compounded liquid that satisfies either of the conditions of A) or (B) is used as the basic material, a reactant is added to this basic material, and the gelation time is adjusted to inject the T-rucaritic injection into the ground. Specially = do something.

A compounded solution exhibiting alkalinity and having a gelation time longer than 1 hour, the active ingredients being water glass with a zero molar ratio of 2.8 JJ or less and an I''iJ soluble reactant.

■An alkaline compound containing water glass, a water-soluble alkali, and a 1liJ-soluble reactant as active ingredients with a gelation time of more than 1 hour.

In the above-mentioned water glass 7 according to the present invention, the above-mentioned (A
), the molar ratio is 2.8 or more, preferably 245 to 0.5
In the above-mentioned (B), 5iOz/Me2O (molar ratio) is preferably 2□8 or more, preferably 288 to 0.5. Here, 510
2 represents the silica content based on water glass, and Me2O represents the alkali content based on water glass and water-soluble alkali.

Furthermore, as the soluble reactant in the above (A> and (B)), a soluble inorganic salt, such as Na.

Monovalent metal chlorides, sulfates, phosphates, bicarbonates, such as K,
(': Alkaline earth metal chlorides such as aCl2, MgCl2, aluminates such as sodium aluminate, lithium aluminate, near-value metal salts such as A1.2Cl3, polyaluminum chloride, aluminum sulfate, aluminum oxide, alum, etc. FeC1,i, FezSO+.

Iron salts such as, etc. are used, but any other inorganic, acid, monoacid, aldehyde, ester, etc. can be used as well.

In addition, the water-soluble r-lukali 2 in the above (B) 1.

In this case, caustic rukali etc. are used.

Furthermore, the reactants added to the basic element 4A include inorganic salts, inorganic acids, organic reactants, cement, slag,
6 ash (slaked ash, calcium carbonate, magnesium carbonate, etc.)
etc., any one can be used.

The basic materials mentioned above have a gelling time of 1 hour or more. This basic material 1. is stinky and alkaline. The inlet solution with the addition of two reactants also becomes alkaline.

Hereinafter, the present invention will be used as an experiment in 111. Adjust the solutions 1, Δ and 3 described in Table-1 to () to a small amount of 4".

Table-1 Table-3 Table-2 Table-4 Table-5 Table-5 Experiment-1 After blending liquid A shown in Tables-1 to 4, Table-5
The gelation time (2
0°C) was measured. FIG. 1 shows the test results (at 20° C.) of gelation time (seconds) versus elapsed time (hours) for a rapid setting formulation in which equal amounts of liquids A and B were mixed together.

The combination of A and B liquids is shown in Figure 1.
2, ■ is Δ-2:B-2, ■ is A, -4:84, ■ is 8-5:B-3, ■ is A, -3:B-4 ■ is A-7:B-
5,■ is A-8:B-2, ■ is A-9:B-4, ■ is A
-11:B-5, ■ is A10:B-1, ■ is A, -18
: B-1 ■ is A-19:B-1, ■ is A-228B-
5, ■ is A-27:B3.

From FIG. 1, it can be seen that when No. 3 water glass is used as liquid A, the gelation time varies significantly with elapsed time.

On the other hand, in the present invention, it can be seen that there is a region in which the gelation time fluctuates very little even after a long period of time has passed after the addition of liquid A. However, it can be seen that when the gelation time of liquid A is shorter than 60 minutes, the gelation time can be relatively easily shortened. From this, it can be seen that it is desirable that the gelation time of the basic material be longer than 60 minutes.

That is, in the case of No. 3 water glass, colloid formation occurs rapidly within the basic material immediately after blending, whereas when the molar ratio is low, colloid formation is delayed. However, if the gelation time is less than 1 hour, the gelation will likely proceed quickly.

Table 6 shows examples of basic materials to which alkaline materials are added. The alkaline material is an alkali or an alkaline salt that does not cause gelation in water glass when used alone, and specific examples thereof include caustic alkali and soda carbonate, with caustic alkali being particularly preferred. A#.

In preparing the solution, the water glass aqueous solution and the reactant aqueous solution are mixed, but caustic alkali may be mixed in either of them in advance.

From Table 6, it can be seen that even when alkali is used, the rapid progress of gelation of the basic material is suppressed, and when reactant 4 is added to this, there is a wide range where the gelation time is constant.

Experiment-2 Injection test into fine sand Fine sand (1) was placed in a mold with an inner diameter of 5 cm and a height of 50 cm.
.

0.07mm5D Io: 0.05mm, D,,
: 0412T, [)9゜0, 151T1m) was filled, and a typical compounded solution shown in Figure 1 was injected from the underside of the mold using a small injection pump.1, while observing the permeation situation at the time of injection, After 24 hours, the bottom and top 10
The cm-long solid bodies were taken out and their -axial compressive strengths were measured. The results are shown in Table-7. The reactant was added to the base material one hour after the base material was retained in the liquid.

As shown in Table-7, the penetration status is classified into groups 1 to 2, as shown in Table-7. .

Incidentally, although experiments were not conducted for items 6 to 9 and 11 to 14 in the implementation shown in FIG. 1, they belong to the first group.

From Table 7, when No. 3 water glass is used as liquid A, coagulation of silicic acid colloid progresses in the initial stage of blending, which inhibits penetration into fine sand and makes the coagulation non-uniform. Furthermore, the strength decreased, and it was found that the whole could not be consolidated homogeneously.

In contrast, it can be seen that according to the present invention, the formation of colloids is prevented, ultimately leading to homogeneous gelation and high strength.

Further, it can be seen that it is preferable for the gelation time of liquid A to be 1 hour or more from the viewpoint of penetration.

In actual injection using the above characteristics of the present invention, it can be used for all injection methods, especially the step of combining liquid A with liquid B for instant setting and injecting instant setting grout,
Ground consolidation can be extremely effectively achieved by combining the steps of merging liquid A with liquid B for loosening, and then injecting loosely setting grout.

Furthermore, for liquid retention of the basic material, water glass ♂ - soluble reactant, or even water-soluble alkali can be optionally mixed. No gel formation occurs.

〔Effect of the invention〕

As mentioned above, the present invention uses a mixture of water glass and a soluble reactant or a water-soluble alkali as a basic material, which can itself be gelatinized, and adds the reactant to the mixture, and injects the obtained injection liquid into the ground. This method solves the drawbacks of conventional injection methods; after retaining the basic material, even if a reactant is optionally added over a long period of time, there is little change in gelation, and the permeability is improved. It is an extremely practical invention, as it has excellent workability, allows for a predetermined gelation time, and also has excellent injection effects because it gels reliably.

[Brief explanation of drawings]

FIG. 1 is a graph showing the relationship between the elapsed time of solution A and the gelation time of Δ and 3 combined solutions.

Claims (1)

[Claims] (1) The basic material is a compounded liquid that satisfies either of the following conditions (A) or (B), and an alkaline injection liquid is poured into the ground by adding a reactant to this basic material and adjusting the gelation time. A ground injection method characterized by injecting water into the ground. [1] An alkaline compound containing water glass and a soluble reactant with a molar ratio of 2.8 or less as active ingredients and having a gelation time longer than 1 hour. [2] A liquid mixture containing water glass, a water-soluble alkali, and a soluble reactant as active ingredients and exhibiting alkalinity with a gelation time longer than 1 hour.