JPS6010066B2 - Composite grouting method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a composite grouting method, and more particularly to a ground consolidation method for uniformly and strongly consolidating or water-stopping soft or leaky ground without pollution.

Soft or leaky ground at building construction sites, etc. (hereinafter simply referred to as soft ground).

) is usually formed on heterogeneous ground with alternating coarse-grained layers and string-grained layers. Requires injection of chemical solution. Conventionally, the following methods are often used to consolidate soft ground.

[li Two-component aqueous glass method] This method uses an aqueous solution of an inorganic reactant or a suspension containing a cement substance (liquid A) and an aqueous water glass solution (liquid B') as the solidifying chemicals. This is a method of merging them using a Y-shaped pipe and press-fitting them into the ground, and the process is very simple and is an excellent method, but it has the following drawbacks.

In other words, the gelation time of the combined liquid of liquids A and B is short, and since liquid A (if it contains cement) is a suspension liquid, these combined liquids have poor permeability and are filled with large pores or coarse particles. It penetrates only into the granular layer and hardly penetrates into the fine granular layer. Therefore, with this method, both the coarse grain layer and the pongee grain layer cannot be firmly consolidated,
A so-called homogeneous reinforced and consolidated ground is not formed. [21
Water glass injection method using an organic reactant This method is a solution-type water glass method that uses an aldehyde compound, ester, etc. as a reactant, and can set a very long gelation time.

Therefore, this method does not require the above-mentioned merging operation, and allows the water glass and reactant to be accurately mixed in advance and injected in a so-called one-shot method.Furthermore, since it is a solution-type chemical solution, it is possible to inject pongee grains. It can be injected homogeneously even to the human layer. However, in this method, the consolidation agent is an aqueous solution, so although it has good permeability, it may deviate from the injection range from large voids in the ground or coarse-grained soil layers.
For this reason, it is difficult to consolidate large voids and coarse-grained soil layers.
It is difficult to form a homogeneous solidified ground. SUMMARY OF THE INVENTION An object of the present invention is to provide a method for solidifying soft ground homogeneously and firmly, eliminating the drawbacks of the above-mentioned known techniques.

According to the present invention, the above-mentioned object is to provide a ground consolidation method that involves injecting a consolidation chemical into soft or leaky ground to solidify the ground. A step of injecting a suspension grout obtained by combining the water glass aqueous solution (Liquid B') into the ground, and {B) Then, at the same time as adding a water-dropping reactant to the water glass aqueous solution (Liquid B'), , a suspension containing cement as an active ingredient (
A step of injecting the solution grout obtained by discontinuing the merging of liquid A) into the ground following the above-mentioned winding process. This is achieved by solidification.

Hereinafter, the present invention will be specifically explained in detail.

First, a suspension (liquid A) and an aqueous water glass solution (liquid B') containing cement as an active ingredient as a solidifying agent are prepared.

Liquid A may contain clay such as pentonite, sand, or the like.

Solution B' is a water glass aqueous solution containing no reactant, and the water glass has a molar ratio (Si02/Pond○) of 1.5 to 5.
．． 0 is often used.

The A liquid and the 8 liquid are combined using, for example, a Y-shaped pipe, and are injected into the soft ground through the injection pipe. Then, in the middle of the injection, a reactant is added to the B' solution, and at the same time, the joining of the A solution is stopped, and thereafter only the water glass aqueous solution (B solution) containing the water-soluble reactant is injected. For example, the following reactions are used.

Esters: Fatty acid esters of monohydric alcohols such as ethyl acetate, methyl acetate, butyl acetate, amyl acetate, etc.

Fatty acid esters of polyhydric alcohols such as ethylene glycol diacetate and glycerin triacetate.

. Intra-molecular esters such as butyrolactone and brolactone. Ethylene glycol monoformate, ethylene glycol monoacetate, ethylene glycol monopropionate, glycerin monoformate, glycerin monoacetate, glycerin monopropionate, glycerin diformate, glycerin diacetate, sorbitol monoformate, Polyhydric alcohol partial esters such as sorbitol monoacetate, glycose acid monoacetate, low degree of polymerization partial saponyl pinyl acetate, etc.

Aldehydes: glyoxal, succinic dialdehyde, malondialdehyde, succinic aldehyde, glutardialdehyde,
Furfural dialdehyde etc.

Amides: formamide, dimethylformamide, acetamide (dimethylacetamide, propionamide,
Butyramide, acrylamide, malondiamide, pyrrolidone, caprolactam, etc.

Alcohols: Monohydric and polyhydric alcohols such as ethyl alcohol, methyl alcohol, amyl alcohol, glycerin, polyvinyl alcohol, and synthetic polymeric alcohols.

Alcoholic beverages: Inorganic acids such as sulfuric acid, hydrochloric acid, and phosphoric acid; organic acids such as formic acid, acetic acid, malonic acid, succinic acid, maleic acid, and tartaric acid.

Salts: Sodium chloride, potassium chloride, sodium sulfate, calcium chloride, etc., other aluminates such as sodium aluminate, potassium aluminate, hydrochlorides such as ammonium chloride, zinc chloride, aluminum chloride, sodium chlorate,
Chlorates such as potassium chlorate, sodium perchlorate, potassium perchlorate, carbonates such as ammonium carbonate, sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate, sodium bisulfate, potassium bisulfate, ammonium bisulfate, etc. Bisulfites, such as sodium bisulfite, potassium bisulfite, and ammonium bisulfite; ciftates, such as sodium silicofluoride, and potassium silicate; borates, such as sodium borate, potassium borate, and ammonium borate; , hydrogen phosphates such as sodium hydrogen phosphate, potassium hydrogen phosphate, ammonium hydrogen phosphate, pyrosulfates such as sodium pyrosulfate, potassium pyrosulfate, ammonium pyrosulfate, sodium pyrophosphate, potassium pyrophosphate, pyrophosphoric acid Pyrophosphates such as ammonium, dichromates such as sodium dichromate, potassium dichromate, ammonium dichromate, permanganates such as potassium permanganate, sodium permanganate, etc.

Lime, gypsum, magnesium oxide, calcium silicate, etc. These may be used alone or in combination. The method of the present invention thus constructed is a suspension grout (mixture of A and B', with a short gelation time).

) consolidates the coarse-grained soil layer, and the solution grout (solution B, long gelling time) penetrates and consolidates the pongee-grained soil layer. By solidifying both of them thoroughly, a homogeneous and strong consolidated ground is formed. There is no possibility of non-uniform consolidation, such as consolidating only the coarse-grained soil layer and not consolidating the coarse-grained soil layer. (The method of the present invention can also be referred to as a "composite grouting method" because the mixed solutions A and B' consolidate the coarse-grained soil layer, and the solution B consolidates the fine-grained soil layer.) In more detail, In the method of the present invention, the confluent liquid first injected is a suspension grout as mentioned above, and the gelation time is short, so it is possible to fill large voids, strata interfaces, or coarse grained layers (all of these can be combined into coarse grained grout). It is called the soil layer.

) and will eventually solidify. Next, the injection of liquid A is stopped, and a reactant is added to liquid B' to obtain liquid B.
If you continue to inject only the liquid, "The rough ground area mentioned above is already filled with the combined liquids A and B', so the B liquid (this is a solution grout, so it has good permeability. Moreover, it will take a long time to gel. ) penetrates into the pongee granular soil layer, which the suspension grout has not been able to penetrate, and eventually completely fills the vertical granular soil layer and solidifies it. The chemical solution consolidates the soft ground continuously from the coarse-grained soil layer to the pongee-grained soil layer, easily forming a homogeneous reinforced consolidation layer.

The method of the present invention requires continuous injection of combined liquids A and B' and then liquid B.

Due to this continuous operation, liquid B is injected before the first injected combined liquids A and 8 are completely hardened within the phase granular soil layer, so liquid B covers the layer of combined liquids A and B'. Therefore, the permeation of Solution B into the Tsumugi grain layer is easily achieved. If A, the injection of the 8 confluence is completed,
If liquid B is injected after a considerable amount of time has passed, A and B'
The combined liquid (suspension grout) quickly gels, and the gel is usually hard, so re-boring is time-consuming.Also, A and B, which have already solidified when B liquid penetrates, are difficult to re-boring. 'The hard gel of the suspension grout inhibits the penetration of Solution B. However, the present invention provides continuous A
, B' combined liquid is switched to B liquid, so that B liquid grout is mixed in before the gelation of A and B' combined liquid grout is completely completed, and the latter is mixed into the woven granular soil layer. There is no need for the inflow and penetration of water to be hindered. Moreover, since the gelation time of Solution B can be adjusted to a very long time, it can permeate into the pongee granular soil layer over a wide range. In addition, in the present invention, a surfactant may be used in combination in order to improve the dispersibility of the cement in liquid A or the reactant in liquid B. Furthermore, in addition to using the Y-shaped pipe described above, liquids A and B' are combined by using a double injection pipe or two parallel injection pipes, which are inserted into the ground, and at the discharge port of the injection pipe, Immediately before and after both liquids A and B' are discharged from the pipe,
Alternatively, it may be performed at the same time as the ejection.

Furthermore, in the method of the present invention, the solidification chemical solution can be injected into the ground using various methods. As an example, this can be done using a very simple rod injection technique. However, the rod injection technique has traditionally had the following drawbacks. In other words, a gap is created between the boring rod and the ground, and the chemical solution squirts out onto the ground surface through this gap, making it difficult for the chemical solution to penetrate into the fine-grained layer. If the gelation time of the chemical solution is increased in order to prevent this, the drug solution will quickly gel, which also has the drawback of being difficult to penetrate. However, if this rod injection technique is applied to the method of the present invention, the above-mentioned disadvantages are completely eliminated and only the advantage of simplicity present in this technique can be effectively utilized. In other words, if the combined liquid of both A and B' is first injected into the ground, not only the coarse voids in the ground but also the gaps will become solidified by the combined liquid, which has a quick gelation time and is strong. If the solids are filled and solidified, and then the injection of liquid A is stopped and only liquid B to which the reactant has been added is injected, the voids or gaps have already been filled and solidified with the combined liquid. Despite the long gelation time, Liquid B does not escape to the ground surface or into the voids, and completely penetrates into the fine grain layer. After injecting the prescribed amount, pull up the rod to an appropriate height, perform the above-mentioned injection again, and then repeat the above-mentioned injection operation many times while pulling the rod. The method of the present invention can be carried out in the following manner. As shown above, the present invention is characterized by a clever combination of suspension grout (merged grout of both liquids A and B') and solution grout (liquid B grout), and it is a simple method that makes great progress. This has been very effective.

The present invention is particularly advantageous when the ground receives a large amount of chemical liquid, and since the injection pump has a large discharge rate, the confluence ratio of liquid A and liquid B' can be maintained relatively accurately.
The liquid does not escape into the groundwater as unreacted substances, and therefore does not cause pollution problems, and is extremely effective.

In addition, in the present invention, instead of adding the reactant to the B' solution, the 8 solution can be replaced with a separately prepared B solution.

Hereinafter, the present invention will be explained in detail by way of examples.

Example 1 An injection test of the present invention was conducted in a humus layer with large voids.

The composition of the solidifying chemical solution is as follows: Solution A (per 100 units): Cement 40k9, bentonite 5k9, water remaining 08 liquid (per 100 units): No. 3 water glass 30, water 70, B liquid (per 103 units): 3 I ordered 30 glasses of water, 3 glasses of ethylene glycol diacetate, and 70 glasses of water.

The A and B' liquids are transported using separate pumps, combined in a Y-shaped tube, and prepared so that they can be injected with an injection tube.
Inject only the liquid 1000 times at 15 times per minute, then B'
The liquids were combined at a flow rate of 15 minutes per minute, and both liquids A and B' were combined and injected. Next, ethylene glycol diacetate was added to the B' solution to obtain a B solution, the injection of the A solution was stopped, and only the B solution was injected at a rate of 2,000 times at 15 strokes per minute.
The result of the on-site permeability test was k = 3.8 x 10-1 before injection.
The arc/sec is k=6.9×10 after injection.
-6 foxes/sec.

In addition, as a result of excavation, cement and pentonite consolidation (consolidation of A and B' combined liquids) was found in large voids in the saprophyte layer (grained layer), and in other areas (fine grained layer). It was found that the solution water glass grout (liquid B) was completely solidified in the layer).

Claims (1)

[Scope of Claims] 1. In a ground consolidation method in which a consolidation chemical is injected into soft or leaky ground to consolidate the ground, (A) a suspension containing cement as an active ingredient (Liquid A) and water glass; Aqueous solution (B
(B) Next, a water-soluble reactant is added to the water glass aqueous solution (B' solution), and at the same time, cement is added to the active ingredient. (C) Coarse-grained soil in the ground. A composite grouting method characterized by homogeneously consolidating layers and fine-grained soil layers.