JP2879252B2 - Soil stabilization treatment method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial application field> The present invention relates to soil particles, particularly small soil particles (approximately 0.1 mm or less), such as red clay and clay, flowing out from the land with rainwater to reduce water quality. The present invention relates to a method for stabilizing soil with a soil stabilizer in order to prevent pollution. In particular, the present invention relates to a method for stabilizing a soil suitable for a construction site that creates a wide area such as a golf course, a residential land development, a forest / farm land development, and the like.

<Conventional Technology> Due to rainwater, minute soil particles such as red clay and clay (hereinafter simply referred to as “soil particles”) flow into a river. However, these soil particles cause water pollution and are not desirable.

As a solution, physical measures such as a sabo dam, a sedimentation basin, and a filtration device are used, but the soil particles are minute and have little effect.

Therefore, recently, a method has been studied in which an agent called a soil stabilizer is applied to the surface of soil to bond and solidify the soil particles, thereby preventing the outflow of the soil particles due to rainwater.

Known examples of the soil stabilizer include a polymer compound dispersion, a mixed solution of liquid water glass and a gelling agent thereof, and a mixed solution of liquid water glass and an aqueous cement solution.

<Problems to be Solved by the Invention> However, when these liquid soil stabilizers are subjected to stabilization treatment of the soil, simply spraying them on the soil surface has the following problems, and leads to practical use. Not.

Even if the soil stabilizer is sprayed on the surface of the soil to be treated, the soil stabilizer cannot be dispersed in the soil unless the mixing operation with the soil particles is performed. It is not performed, and it is difficult to obtain a practical soil stabilizing effect.

This phenomenon is particularly remarkable when the soil to be treated is hard due to the adhesion of the soil particles to each other, for example, in the case of dry clay.

When the mixing operation is performed after the soil stabilizer is sprayed on the surface of the soil to be treated, a machine / tool for cultivating the soil is used. In these, the soil particles in the state of being aggregated by the soil stabilizer tend to adhere during the mixing operation, and the aggregated soil particles must be removed from the device every short time, and the mixing operation efficiency is extremely poor.

Further, when the soil stabilizer is of a short-curing type (about 10 to 1 minute) (for example, a gelling phenomenon between a liquid water glass solution and a phosphate solution), it is immediately solidified even if the soil stabilizer is sprayed. Therefore, even if the soil is stirred, a substantial mixing effect cannot be obtained.

An object of the present invention is to solve the above problems,
It is an object of the present invention to provide a method for stabilizing a soil with a soil stabilizing agent.

<Means for Solving the Problems> As a result of intensive development efforts to solve the above problems, the present inventors have conceived of a soil stabilization treatment method having the following configuration.

The invention according to claim 1 is a method for stabilizing a soil with a soil stabilizer, wherein the soil stabilizer is prepared as it is or in a liquid state, and high-pressure injection is performed on the surface of the soil to be treated. The soil stabilizer is dispersed in the soil to be treated while stirring the soil to be treated.

The invention according to claim 2 is characterized in that the high-pressure injection of the soil stabilizer is performed in combination with hard particles such as sand.

<Embodiment> (1) The apparatus for injecting the soil stabilizer at high pressure is not particularly limited, but an apparatus capable of adjusting the pressure and the discharge flow rate is desirable.

In the case of a two-pack type in which the soil stabilizer is composed of a main agent and a curing agent, an external mixing method may be used in which mixing is performed immediately after injection from a separate injection gun, but in the injection gun or in a supply path to the injection gun, An internal mixing system for mixing may be used.

(2) Hard particles such as sand are added to the above-mentioned soil stabilizer in order to increase the effect of excavation and stirring on the soil, and 50 to 3 parts by weight based on 100 parts by weight of the solid content of the soil stabilizer.
00 parts by weight. If the amount is less than 50 parts by weight, it is difficult to obtain increased agitation hardening. If the amount exceeds 300 parts by weight, the contribution of the soil stabilizer to the soil becomes small, which is not desirable. The particle size of the hard particles is usually 1 to 10 mm.

(4) Next, the procedure of the soil stabilization method will be described.

The soil stabilizer is prepared as it is or in a liquid state and stored in a stabilizer tank. In the case of a two-pack type, store it in a separate tank.

Then, the container and the hose are connected to the pressurizing device, and the injection nozzle is attached to the end of the hose.

The soil stabilizer is supplied from a tank to a pressurizing device, pressurized, and sprayed from a nozzle for spraying.

Regarding the spraying operation, the sprayed liquid material violently collides with the surface layer of the soil to be treated, and a good mixing state between the soil stabilizer and the soil particles is obtained while excavating and stirring the soil in the surface layer portion. The pressure and the nozzle diameter are adjusted as described above. Usually, the pressure is 50 to 250 kgf / cm ² . 50kgf / cm
^{In 2} it is difficult to excavate and mix the soil, and 300kgf / cm
^If it exceeds ² , the stirring power is too strong, and the scattering of the soil particles occurs, which undesirably lowers the stirring effect.

The pressure of the solution and the diameter of the nozzle affect the efficiency with which the solution excavates and mixes the soil surface layer. The diameter of the nozzle is usually 5 to 15 mm.

In this way, the sprayed and dispersed soil stabilizer mixes the soil particles well while simultaneously excavating and stirring the soil particles.
As a result, the mixing operation is performed simultaneously with the spraying operation, and no special mixing operation is required.

Even when the soil stabilizer is ejected and collided, hard particles such as sand can be sprayed at the same time as the soil stabilizer when the surface layer of the soil is scattered into a soil that is hard enough to be excavated and agitated. desirable.

When an appropriate amount of a hard substance such as sand is sprayed simultaneously with the soil stabilizer to act on the surface of the soil to be treated, the excavating and stirring action can be increased. The reason cannot be determined,
The effect of the soil stabilizer to wet the soil particles, hard particles,
This is because the excavation action that collides with the soil particles and breaks and separates the cohesive soil is synergistic.

<Operation / Effect of the Invention> The soil stabilization method of the present invention is to excavate and stir the soil to be treated by preparing the soil stabilizer as it is or in a liquid state and injecting it at high pressure onto the surface of the soil to be treated. Since the configuration is such that the soil stabilizer is dispersed in the soil to be treated, the mixing operation with the soil particles is completed at the same time as the spraying operation of the soil stabilizer, so that a special mixing operation is unnecessary, and the soil stabilizer is not required. The soil stabilization treatment by the method can be put to practical use.

That is, the soil stabilization treatment with the soil stabilizer can be performed without requiring a large number of steps. In addition, it becomes unnecessary to remove the aggregated soil particles from the mixing device every short time due to the attachment of the soil particles aggregated by the soil stabilizer during the mixing operation. Furthermore, even if the soil stabilizer is a short-time curing type, there is no need to consider the curing time, and a wide range of chemicals can be used as the soil stabilizer. Also, since a short-curing type soil stabilizer can be used, a small amount of spring water, or a soil particle in a wet state where a small amount of flowing phenomenon has occurred, can be quickly solidified, and the soil stabilizer can be used. Can be applied to a wider range of places.

<Examples> Test examples performed to confirm the effects of the present invention are described below.

As the inorganic soil stabilizer, a soil stabilizer composed of liquid water glass and a gelling agent and commercially available under the trade name Nikahard (manufactured by Nippon Chemical Industry Co., Ltd.) was used.

Epoxy resin dispersion is used as a polymer compound-based soil stabilizer, trade name, Adeka Epoxy EP-0425 (manufactured by Asahi Denka Kogyo Co., Ltd.), and as a gelling agent, trade name, Epoki 350M (Mitsui Toatsu Co., Ltd.) was used from commercial products.

Table 1 shows the formulation and curing time of these soil stabilizers.

As a device that can pressurize and feed the preparation liquid of soil stabilizer,
Built-in suction pump, liquid pressure 0-400Kgf / c
^Two airless pumps (manufactured by Asahi Okuma Co., Ltd.) equipped with a function capable of varying the liquid discharge rate in the range of 0 to 401 / min in m ² were prepared.

The pressure and the discharge amount were adjusted and used each time so that the medicine of each soil stabilizer could be effectively ejected.

As a device capable of mixing individually pressurized soil stabilizers (indicated as solvent A and solvent B in the table), a static mixer was attached at the end of the hose, that is, in front of the nozzle, and each was fed under pressure. The drug solution was guided by a separate hose and mixed immediately before jetting.

As a separate mixing method, a nozzle may be attached to the tip of the hose of each chemical solution of the soil stabilizer, and the nozzle may be jetted toward the same point on the surface of the soil to mix while excavating and stirring the soil particles. .

The diameter of the nozzle was adjusted so that the drug solution could be intensively delivered to a predetermined distance.

Hard particles used in combination with the soil stabilizer, the distribution of particle size,
The test was carried out using two types of river sand, each having a size of 1 to 4 mm (drug samples No. 1 and 2) and 3 to 9 mm (drug samples No. 3 and 4).

In addition, as a provisional means for injecting river sand simultaneously with the soil stabilizer, a metal outer cylinder with a diameter of 70 mm and a length of 450 mm was attached to the nozzle outlet, 100 mm from the tip
A hole with a diameter of 8 mm was made in the position of, and river sand was replenished from this hole to make the soil stabilizer spouted from the nozzle turbid.

Using these methods, a red soil or clay soil was selected as an object to be subjected to a soil stabilizer spray test, and a 2 × 2 m square area was sprayed on each soil.

Example 1. The soil stabilizer adjusting solution of each composition shown in Table 1 was pressurized,
The mixture was jetted from a nozzle through a mixing device and sprayed on a red soil soil (moisture content, 5.8%) and a clay soil (moisture content, 7.8%) having a dry appearance.

Then, all the injected soil stabilizers were well mixed with the soil particles.

Table 2 shows the results of the injection pressure, the nozzle diameter, and the thickness of the stabilized layer (solidified layer) measured after the lapse of time, which were measured in the test.

In order to compare and judge the results of the above test, a test was conducted in which the soil stabilizer was dropped and sprayed onto the surface of each soil without applying pressure using a watering device.

Table 3 shows the results of the amount of the applied medicine and the thickness of the solidified layer after aging.

Example 2 Using the same method as in Example 1, the soil stabilizers of the respective formulations shown in Table 1 were mixed with red soil (moisture content: 36.1%) having a wet appearance and clayey soil. Soil (water content 3
1.4%).

Then, the injected soil stabilizer was well stirred and mixed with the soil particles.

Table 4 shows the results of the pressure of the solution, the nozzle diameter, and the thickness of the cured layer measured after the lapse of time.

In addition, in order to compare the results of the above test, a test was performed in which a soil stabilizer was sprayed onto the surface of each soil using a watering device without applying pressure.

Table 5 shows the results of the amount of the applied medicine and the thickness of the solidified layer after aging.

Example 3 The soil stabilizer of each formulation shown in Table 1 was pressurized and conveyed in the same manner as in Example 1, and river sand was replenished using an outer cylinder attached to the tip of the nozzle, along with the solution. Sprayed, dry, hardened clayey soil (water content 2.4
%).

Then, the soil stabilizer and the injected river sand quickly excavated and stirred the surface layer of the clay, and a favorable mixed state of the soil stabilizer and the soil particles was obtained.

Regarding the test results, the liquid pressure and the nozzle diameter are the same as in Example 1 and are therefore omitted, but Table 6 shows the thickness of the solidified layer after aging.

As shown in the results shown in Tables 1 to 6, it can be seen that the examples according to the method of the present invention are clearly superior in the effect of spraying the soil stabilizer solution.

In addition, the thickness of the solidified layer measured after the lapse of time shown in each table is measured using an electric drill equipped with a cylindrical cutting blade having a diameter of 80 mm, from the surface of the solidified layer cut through from the surface of the soil. It was measured in the direction of the earth axis.

Claims (2)

(57) [Claims] 1. A method for stabilizing a soil with a soil stabilizer, wherein the soil stabilizer is prepared as it is or in a liquid state, and is sprayed at a high pressure onto the surface of the soil to be treated. A method for stabilizing a soil, wherein the soil stabilizer is dispersed in the soil to be treated while excavating and stirring the soil. 2. The method for stabilizing soil according to claim 1, wherein the high-pressure injection of the soil stabilizer is performed using hard particles such as sand.