JP2588053B2 - Ground injection method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a ground injection method in which a specific injection liquid is injected into the ground to consolidate the ground, and the gelation time of the injection liquid can be easily adjusted in detail. And a ground injection method with excellent permeability.

[Conventional technology]

Conventionally, as an injection liquid for ground consolidation,
Inorganic salts, organic salts or glyoxal and esters,
Further, a water glass grout which is made to gel by adding cement or the like is known.

In the above, in the case of using an aqueous solution of inorganic salt as the inorganic salt, the gelation time greatly changes due to a slight difference in the amount of the inorganic salt in adjusting the gelation time, or it is not gelled at all just slightly too little. A phenomenon occurred, and consolidation was uncertain.

In addition, in the case of a poorly soluble inorganic salt or cement, there is a problem that permeability is poor, and in the case of the above-mentioned organic system, BOD and COD of groundwater are increased.

In each of the above-described examples, particularly when a water-soluble inorganic salt is used, it is expected that an extremely useful injection solution will be obtained if the gelation is performed reliably and the gelation time can be easily adjusted.

Therefore, in order to realize this expectation, a mixture of No. 3 water glass and NaCl, KCl or an alkaline earth metal salt in advance is used as solution A, another aqueous solution of the reactant is used as solution B, and these solutions A and B are combined. An injection method has been proposed. However, when NaCl, KCl or alkaline earth metal salt is mixed with No. 3 water glass, colloid is rapidly formed in the mixed solution. There has been a problem that the gelation time is significantly different and it is difficult to adjust the gelation time.

Also, an injection method is known, in which an acidic water glass formed by adding a strong acid to water glass is used as a basic material, and an alkali agent is added to the base material. However, there is a disadvantage that the gelation time is difficult to adjust.

[Problems to be solved by the invention]

The method of mixing a water glass and a reactant in advance and using a formulation that can gel itself as a basic material, and adding a gelling agent to this is a method of gelling the basic material without fail. In addition, there is an advantage that the injection liquid whose gelation time is adjusted always gels and the solidification property in the ground is extremely excellent.

However, the biggest disadvantage of this method is that after blending the basic materials,
The formation of colloid therein proceeds rapidly, and the formation is accelerated as time elapses after compounding until injection. Therefore, even if the gelling time is adjusted by adding a gelling agent (Solution B) to the basic material (Solution A),
The gelation time of the mixed liquid A and B varies depending on the elapsed time from when the basic material (liquid A) is mixed to when liquid B is mixed with liquid A, and it is extremely difficult to obtain a predetermined gelation time.

In an actual site, various operations are performed from the preparation of the liquid A, which is a basic material, to the mixing of the liquids A and B until the injection, for example, the stop of the injection due to a change in the injection stage during the injection process, the injection pipe. Flushing due to clogging, temporary interruption of injection due to other troubles, interruption of injection during lunch break, adjustment of pump, etc., or adjustment of blending of liquid B itself, difference in distance to individual injection pipe A etc.
It takes more or less time until the liquid B is mixed with the liquid and injected, and the time is not constant.
Therefore, if a method is found in which the gelation time is hard to change despite the length of time elapsed from the blending of the solution A to the addition of the solution B, this injection method can be used to easily set the gelation time. It should be able to become an extremely excellent and highly practical method.

Also, when the construction becomes large-scale, a large amount of injection material is made at a time, and then it is sent to many injection pipes using a large number of pumps, and the gelling time is adjusted by adding a gelling agent to each, and injection is performed. However, the larger the amount of injection material created at a time, the longer it takes from the start of injection to the time when the injection material is used up. If the number is small, an injection method suitable for large-scale construction will be possible.

Therefore, an object of the present invention is to easily adjust the gel time,
Another object of the present invention is to provide a ground injection method which is excellent in permeability and has improved the disadvantages of the above-mentioned known technology.

[Means for solving the problem]

To achieve the above object, according to the present invention, an alkaline compounded liquid containing water glass and an aluminum compound as active ingredients and having a gelation time of 1 hour or more is first prepared as a basic material, and reacted with this basic material. The method is characterized in that an alkaline injection liquid obtained by adding an agent is injected into the ground.

In the present invention described above, the water glass has a molar ratio of 5.
A water or powdered water glass of 0 to 0.5 may be used, or a mixture of water glass and sulfuric acid or alkali may be used.

Examples of the aluminum compound include aluminum chloride, sulfate, aluminum sulfide, and aluminum hydroxide such as aluminum chloride, polyaluminum chloride, aluminum sulfate, and alum.

Further, as a reactant to be added to the basic material, an arbitrary one such as an inorganic salt, an inorganic acid, an organic reactant, cement, slag, and lime is used.

The above-mentioned basic material has a gelation time of 1 hour or more and is alkaline, and the injection liquid obtained by adding a reactant to this basic material also exhibits alkalinity.

 Hereinafter, the present invention will be described in detail by experiments.

 The solutions A and B are adjusted as shown in Tables 1 and 2.

Experiment-1 After blending solution A shown in Table-1, this was mixed with B in Table-2.
Gelation time (20 ° C) corresponding to the time until the liquid is mixed
Was measured. FIG. 1 shows the test results (20 ° C.) of the gelation time (seconds) with respect to the elapsed time (time) of the quick-setting compounded mixture of the same amounts of the liquids A and B.

In FIG. 1, the combination of liquids A and B is A-1: B-
1, A-2: B-1, A-3: B-1, A-4: B
-1, A-5: B-1 is A-6: B-1, A-7: B
It is -1.

From FIG. 1, it can be seen that when the alkaline earth metal salt such as calcium chloride (the same applies to the Mg salt) and the alkali metal salt such as sodium chloride are used as the solution A, the gelation time greatly fluctuates with the lapse of time. I understand. This is because alkali metal salts such as sodium chloride or alkaline earth metal salts rapidly form colloids immediately after blending and have a heterogeneous structure.
It seems to have a significant effect on gelation.

In contrast, in the present invention of sample numbers A-5 to A-7, A
It can be seen that there is a region where the fluctuation of the gelation time is extremely small even after a long time after the mixing of the liquid. However, it can be seen that when the gelation time of the solution A is shorter than 60 minutes, the gelation time is relatively easily shortened. This indicates that the gel time of the basic material is preferably longer than 60 minutes.

Experiment-2 FIG. 2 shows an example of a slow-setting mixture in which the same amount of the solution A and the solution B were mixed in the same manner as in the experiment-1. The combination of liquids A and B is A-1: B-2, A-3: B-2, A-2: B-4,
Is A-4: B-3, is A-2: B-5, is A-5: B-5,
Is A-5: B-4, A-7: B-3 is A-6: B-2.

From FIG. 2, it can be seen that the same tendency as in Experiment 1 is obtained also in the case of the loose grout.

[Action] By using the aluminum compound in the present invention, the reason that there is a region where the gelation time does not fluctuate even if the solution B is added after a long time has elapsed after the formulation of the solution A is probably because aluminum is an amphoteric electrolyte substance. In addition, the reaction of aluminum is slow, or the silica colloid containing silica and aluminum ions has a stable, hardly agglomerated surface chemistry, and gelation rapidly progresses only after a considerable period of time. It seems to have the characteristic that.

Further, if the gelation time of the solution A in the present invention is shorter than 60 minutes, the stability tends to decrease, so that it is considered that the region where the gelation time does not fluctuate easily becomes small.
Therefore, the gelation time of the solution A in the present invention is more preferably longer than 1 hour.

The present invention can be used for all injection methods utilizing the characteristics of the injection liquid described above. In particular, a step of injecting the liquid B for instantaneous setting into the liquid A and injecting the instantaneous setting grout, Injection can be performed very effectively by combining the step of injecting the loosening grout by mixing the binding liquid B.

In the above description, the liquid A may be a mixture of water glass and an aluminum compound as essential components and a reactant added thereto. Further, the water glass and the aluminum compound can be arbitrarily mixed when applied to the liquid production of the basic material. For example, if both liquids are rapidly mixed by a pressurized jet confluent mixing method, a partial gel does not occur.

[Effects of the Invention] As described above, the present invention uses a mixture of water glass and an aluminum compound as a basic material, which can gel itself, and injects an injection solution obtained by adding a reactant into the ground. This solves the drawbacks of the conventional injection method.After the basic material is prepared, even if a reactant is added arbitrarily over a long period of time, the gelation does not fluctuate and the permeability increases. Excellent, excellent workability,
This is a very practical invention that can obtain a predetermined gel time and has a good injection effect because gel is surely formed.

[Brief description of the drawings]

FIG. 1 is a graph showing the relationship between the elapsed time of liquid A and the gelation time of liquids A and B in the rapid mixing of liquids A and B, and FIG. It is a graph showing the relationship between the elapsed time of the liquid and the gelation time of the combined liquids A and B.

Claims (1)

(57) [Claims] An alkaline mixed solution containing water glass and an aluminum compound as active ingredients and having a gelation time of 1 hour or more is first prepared as a basic material, and an alkaline injection solution obtained by adding a reactant to this basic material. A ground injection method characterized by injecting a liquid into the ground.