JPS5837079A - Soil stabilization - Google Patents

Abstract

PURPOSE:To stabilize soil, by injecting into soil a water glass grouting agent contg. an acidic alkali metal sulfate and potassium chloride as hardeners, whereby gel time of soil is made adjustable within several seconds. CONSTITUTION:In an injection technique for stabilizing soil by injecting a water glass grouting agent into soil, a reagent soln. contg. 100pts.wt. acidic alkali metal sulfate and 5-100pts.wt. potassium chloride as hardeners is used. Further, not more than 30pts.wt. water-soluble neutral or basic bivalent or polyvalent metal salt may be incorporated in said reagent soln. contg. the hardeners. As said neutral or basic salt, magnesium chloride, magnesium sulfate, basic magnesium carbonate, aluminum sulfate and aluminum chloride are preferred from the viewpoint of solubility or liquid temperature characteristics of gel time.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an injection method for stabilizing soil quality by injecting a water glass grouting agent into soil.

Specifically, the present invention relates to a soil stabilization method using a water glass grouting agent, in which the gel time can be adjusted within a few seconds using an acidic sulfate-alkaline curing agent.

Conventionally, when acidic alkali sulfate is used as a hardening agent for water glass grouting agents, it is used as a reinforcing agent or a gel time adjusting agent such as Karimitsuban, monosodium phosphate, oxidation! It is known to use gnesium and aluminum sulfate together.

However, these curing agents have not yet been fully satisfactory due to different solubility at low temperatures, large volumetric shrinkage of the cured product, and low strength.

IIIK Recently, by using a super-instant-setting cap grouting agent with a gel time of 2 to 5 seconds 1if, it is possible to ensure the ground improvement effect and prevent pollution from chemical spills. There are various problems in reducing the time to 2 to S seconds, and the range of usage ratios for acidic alkali sulfate, magnesium chloride, calcium chloride, etc. is narrow, and the resulting cured product may become a non-uniform gel or have poor strength. It is still not satisfactory as it is small and there is a lot of separation.

An object of the present invention is to provide a method for stabilizing soil quality using a hardening agent that enables ultra-instant hardening with a gel time of about 2 to 5 seconds.

Another object of the present invention is to shorten the gel time and increase soil strength by using a hardening agent that can obtain a uniform gel even when a large amount of neutral or basic salts of divalent or higher metals is added. There are several methods that provide stabilization methods.

Still another object of the present invention is to provide a method for stabilizing soil quality using a curing agent that uniformly gels, has high soil strength, and causes little detachment.

Another object of the present invention is to provide a method for stabilizing soil quality using a curing agent that does not cause any deterioration in performance, especially at low temperatures.

That is, the soil stabilization method of the present invention is an injection method in which a water glass grouting agent is injected into the soil to stabilize the soil, and the hardened steel includes: 0) Acidic alkali sulfate 100 parts by weight (b) Potassium chloride 5 to 100 It is characterized by using an electrolyte containing parts by weight.

In the present invention, acidic alkali sulfate refers to acidic sodium sulfate and/or acidic potassium sulfate.

In the hardening one-drug medicine cabinet used in the present invention, water-soluble two-drugs are further added.
30 parts by weight or less of a neutral salt or basic salt of a metal having a valence or higher,
It can preferably be contained in an amount of 30 parts by weight.

Neutral or basic salts of water-soluble divalent or higher valent metals that can be used in the present invention, Oa, Mgsmut, Fe
sulfates, carbonates, nitrates, and hydrochlorides (including chlorides), but due to their solubility and liquid temperature characteristics of gel time, magnesium chloride, magnesium sulfate, and basic carbonate! Gnesium, aluminum sulfate, and aluminum chloride are preferred.

In particular, when aluminum products are treated with chloride, the main component is aluminum chloride, which is recovered from the casing that generates noise.
This substance exhibits remarkable performance when used in combination with potassium chloride, and the use of such a substance, which can be called a child's waste product, is also meaningful from the point of view of effective use of resources.
Further, the potassium chloride may contain sodium chloride to the extent that it does not interfere with dissolution and hardenability at low temperatures.

In addition, as the water glass used in the present invention, JI8-
No. 3 or No. 4 sodium silicate as defined in 1408 is preferred, and No. 4 sodium silicate is particularly preferred from the viewpoint of gelling properties at low temperatures and volumetric shrinkage of the gelled product.

The amount of curing agent used in the present invention relative to the grouting agent varies depending on the type of grouting agent and cannot be unconditionally determined, but for example, when using Silica No. 15 as the grouting agent,
Normally, the curing agent of the present invention is mixed with about 20 to 35 # of the hardening agent of the present invention to 200 t of the solution diluted with 100 t of water and 200 tK of water.
llj and use it. In particular, the curing agent of the present invention is
If the above is used, a gel time of 2 to S seconds can be obtained. Moreover, when it is desired to lengthen the gel time, an amount of 22 kF or less may be used.

According to the soil stabilization method of the present invention, it is easy to adjust the gel time of the water glass grout agent and to achieve instantaneous setting of several seconds or less even at low temperatures.

In addition, when performing such super instantaneous hardening for 2 to 6 seconds, K
Fi, it is necessary to avoid adding other ingredients to the grouting agent.

★Gel time can be freely selected by changing the ratio of acidic alkali sulfate and potassium chloride, and gel time can be adjusted, especially gel time can be shortened by adding neutral or basic salts of divalent or higher valent metals. This has the effect of reducing the volumetric shrinkage rate of the homogel. That is, there is little syneresis (syneresis).

With conventional curing agents, it was necessary to heat the IIi melting tank at a low temperature of ~5°C using a heater attached to the IIi melting tank to accelerate the dissolution rate and achieve a gel time of 2 to 5 seconds. Potassium is highly soluble at low temperatures,
It has good solubility compared to the conventionally used potassium dH upan. Furthermore, potassium chloride acts as a solubilizing agent and increases the rate of dissolution of acidic sodium sulfate.

As described above, by appropriately adjusting the amount of the Fi curing agent used in the method of the present invention, it is possible to achieve ultra-instant curing for 2 to 3 seconds at the initial stage of injection; This is a book where you can freely create gel time sections.

Further, in the method of the present invention, by using the above-mentioned curing agent, the above-mentioned gel time can be easily adjusted even at low temperatures around 0° C., and there is no deterioration in performance.

Further, the method of the present invention exhibits extremely excellent effects in that uniform gelation is possible, the volumetric shrinkage of the obtained cured product is small, and the strength of the cured product is extremely high.

Examples of the present invention will be shown below to specifically clarify the effects of the present invention.

Example 1~? and Comparative Example 1.2 (Measurement of gel time)
Dilute silicon 1S No. 25- with 25 ml of water to make a liquid. The aqueous solution @5Q11j of the curing agent in Table 1 below was made into sea bream and used as liquid B. After heating the liquid and BiI to a predetermined temperature (10°C), the mixture was mixed and the gel time was measured.

The results were as shown in Table 1. 1 of the hardening agents in Table 1!
The numbers in 1ljIIDIII indicate the blending ratio (weight ratio) of each component (the same applies hereinafter).

Examples 10 to 14 and Comparative Examples 3 and 4 (Measurement of syneresis) Using the curing agents shown in Examples 1 to 9 and Comparative Examples 1 and 2, both Mu and B solutions prepared in the same manner were used. A gelled product was prepared, and 100α of the gelled product was placed in a closed container.
Syneresis was measured by measuring the water separated from the gelled product after storing it in a constant temperature bath at .degree. C. for 24 hours.

The results were as shown in Table 2.
U Shown in Example (Comparative Example) A above (the same applies hereinafter).

Table 2 Examples 15 to 19 and Comparative Examples 5 to 6 Gel time can be measured using Silicon No. 14 (ADEKABOND, manufactured by Asahi Denka Kogyo Co., Ltd.) in the same manner as in Example 1 shown above, and the results are as follows. It was as shown in Table 5.

Table 5 Example 20.21 and Comparative Example 7 Syneresis after 48 hours was measured using silica No. 4 in the same manner as in Example 10 described above.

The results were as shown in Table 40.

Table 4

Claims (1)

[Claims] 1. In an injection method in which a water glass grouting agent is injected into soil to stabilize the soil quality, as a hardening agent (a) 100 parts by weight of an acid alkali sulfate (b)
A soil stabilization method characterized by using a chemical solution containing 5 to 100 parts by weight of potassium chloride. 2. The soil stabilization method according to claim 1, wherein the iI-forming agent contains a water-soluble neutral salt or basic salt of a divalent or higher valent metal in an amount of not more than part by weight of SO.