JP2776950B2 - Ground surface stabilization method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a suitable land used for preventing erosion and greening slopes such as roads, river embankments, lands, railways, and slopes of hillsides. It relates to a surface stabilization method.

(Prior art) Soil or exposed ground surface such as rock, soft rock, etc.
It is easily eroded by frost and the like, and is preferably stabilized by a greening method. In particular, conventionally, rocks, soft rocks, soilless soils, and the like, on which slopes where plant growth is difficult, are sprayed with soil containing a synthetic resin emulsion such as vinyl acetate to form a relatively thick coating layer. Thick layer soil stabilization method is frequently used.

However, when spraying such soil, the thicker the covering layer, the longer it takes days to solidify and fix the soil. . A method of rapidly solidifying the soil by using cement as a consolidating agent has also been proposed.
With this method, the alkalinity of the cement inhibits seed germination.

Therefore, a construction method using a clay containing gypsum has been proposed in JP-A-60-137212. According to this method, although effective for early consolidation of the soil, the soil is easily dried and is poor in water absorption and water retention. Therefore, the seeds may be succumbed to dying, especially during the early stage of germination.

(Problems to be Solved by the Invention) The present inventors have conducted intensive studies to solve the above-mentioned problems in the conventional soil stabilization method, and as a result, the synthetic soil contains emulsion resin, fly ash and calcium hydroxide. In addition, the present invention has been found to preferably improve the germination rate of seeds and improve the growth of plants by adding a pH buffer solution.

(Means for Solving the Problems) The ground surface stabilization method according to the present invention is characterized in that a soil containing synthetic resin emulsion, fly ash and calcium hydroxide is applied to the ground surface.

The soil according to the present invention contains a synthetic resin emulsion. By using such a soil, it is possible to enhance the connectivity of the soil particles and the like, and to prevent the soil from flowing out due to rainfall. As the synthetic resin emulsion, polyvinyl acetate, ethylene-vinyl acetate copolymer, vinyl acetate-acrylate copolymer, styrene-butadiene copolymer, emulsions such as polychloroprene are preferably used. Polyvinyl acetate emulsion is preferably used because it has an excellent effect of enhancing the binding property of the soil particles and is inexpensive.

When these synthetic resin emulsions are too much, the soil is excessively hardened and solidified, or the synthetic resin coating covers the soil particles, impairing water absorption and air permeability. Germination disorders. On the other hand, when the amount is too small, it is difficult to bind the soil particles, and the soil is poor in water absorption and retention. Therefore, for example, even after drying, it is eroded by rainfall, becomes muddy, and easily collapses. Therefore,
In the present invention, the synthetic resin emulsion is used as a synthetic resin in the range of 1 to 10% by weight of each soil.

In the present invention, fly ash and calcium hydroxide as a consolidating agent are not particularly limited because they depend on the soil used, but usually 2.5 to 6.0 of the soil.
It is used in the range of weight%. If the amounts of the fly ash and calcium hydroxide are too small, the hardening action is poor and the soil cannot be solidified in a short time. However, when the amount is too large, the soil becomes too hard, which may cause germination failure of seeds.

In the present invention, the preferred mixing ratio of fly ash and calcium hydroxide is generally 20 to 25 to 5 to 10
Is more preferably selected depending on the target ground. For example, usually, the preferred mixing ratio of fly ash and calcium hydroxide is 20
Pair 5 is preferably employed. However, when the target ground is rock or soft rock that retains water, a ratio of 25 to 10 or less in which the ratio of calcium hydroxide is large is preferably adopted. However, in any case, the blending of calcium hydroxide in a proportion larger than the above range moderately solidifies the base layer, thereby reducing the water absorption or increasing the pH, so that the decrease in germination is reduced. May be invited. On the other hand,
If the ratio is smaller than the above range, the solidification of the ground surface is poor, and the soil may easily collapse due to rainfall.

In the present invention, it is advantageous to include a pH buffering agent having an effect of adjusting the pH of the soil to a range suitable for germination of plants. By using such soil, the germination rate of seeds is improved, and plants grow well. As the pH buffering agent, aluminum sulfate, lime superphosphate, or the like is preferably used, and usually 2 to 6 parts by weight based on 100 parts by weight of the binder. When the amount of the pH buffering agent is too small, the above-mentioned effects cannot be expected to be exerted. On the other hand, when the amount is too large, the germination rate of the plant is reduced, or after germination, the leaf tip yellow due to chemical damage. May cause strange.

In addition, the use of a pH buffering agent coagulates the synthetic resin emulsion, promotes water separation of the emulsion, and allows the solidification of the base agent to proceed in a short time, thus easily stabilizing the soil. It also has advantages that can be obtained.

Furthermore, in the present invention, it is advantageous that seeds or rhizomes are mixed and dispersed in the soil. By using such a soil, the soil is solidified in a short time, and at the same time, air permeability,
It is excellent in water absorption and water retention and has flexibility suitable for germination and growth of plants, so that greening can be advantageously performed.

In general, the soil used in the present invention is prepared by mixing and dispersing fly ash and calcium hydroxide in organic materials, peat moss, bark compost, woody cellulosic fibers, and the like, and then optionally mixing the synthetic resin emulsion with water. It can be obtained by diluting and mixing, and further, if necessary, adding a pH buffer, a seed or a rhizome, and uniformly dispersing and kneading.

The method of applying the soil obtained in this way to the ground surface is not limited at all, and can be performed by a general seed spraying method (spraying method). May be based on the pressure spraying method.

(Effects of the Invention) As described above, according to the method of the present invention, fly ash and calcium hydroxide are contained in the soil, so that the soil has excellent water-absorbing and water-holding properties, and furthermore, the soil has a pH-drying property. By including the agent, the seeds do not cause germination disorders, the germination rate of the seeds is improved, and the plants grow well.

(Example) Hereinafter, the present invention will be described with reference to examples.

Example 1 The composition of the soil used in the present invention was based on 100 parts by weight of peat moss, as shown in Table 1, and as shown in Table 1, synthetic resin emulsion (solid content concentration 50% by weight), fly ash, calcium hydroxide, and In this case, a pH buffer was added, and the mixture was uniformly kneaded to prepare a soil.

It is inclined at 35 ° angle to the horizontal plane, set up a slate plate, a thickness of 1 above soil dressing on the inclined surface of the area 1000 cm ²
A 00 mm layer of soil was provided. After curing for 4 hours or 24 hours, artificial rain of 5 mm per minute was allowed to fall for 30 minutes, and the amount of outflowing customer soil was examined. The results are shown in Table 1.

Separately, a soil was prepared in the same manner as described above, except that whipping rub grass, white clover, and kentatsuki 31 were mixed into the soil as seeds, and a soil layer was provided on a stout plate. At that time, after sowing except for the covering soil after sowing to an upper layer portion having a thickness of about 5 to 10 mm, the soil was uniformly covered with the remaining soil. The germination rate 30 days after sowing was examined. The number of grains in each seed is
100 tablets. The results are shown in Table 1.

In Table 1, abbreviations for the synthetic resin emulsion are as follows.

PVAc: polyvinyl acetate Et / VAc: ethylene-vinyl acetate copolymer VAc / Ac: vinyl acetate-acrylate copolymer St / Ac: styrene-acrylate copolymer PBAc: polybutyl acrylate St / Bd: Styrene-butadiene copolymer Comparative Example 1 For comparison, a synthetic resin containing no emulsion, flyash and calcium hydroxide (Experiment No. 1) and flyash and calcium hydroxide as binders were contained. With soil containing no synthetic resin emulsion (Experiment Nos. 2 and 3) and gypsum as a binder, along with clay containing polyvinyl acetate emulsion (Experiment No. 4) and gypsum as a binder, A soil containing an ethylene-vinyl acetate copolymer (commercially available powder) (Experiment No. 5) and a soil containing only cement as a binder (Experiment No. 5) Using each of No. 6), the amount of outflowing customer soil after artificial rainfall and the seed germination rate were examined in the same manner as in the example. The results are shown in Table 1.

Example 2 A soil having a composition shown in Table 2 was sprayed on a bedrock (having an area of 12.9 m ² ) having a slope of 40 ° or a slope of 40 mm to form an 80-mm thick soil layer.

On the other hand, a section is provided adjacent to the above-mentioned soil, and a coating layer having a thickness of 80 mm made of the soil formed by adding gypsum to one of the sections as shown in Comparative Example Experiment No. 4 in Table 1. Was provided. In the remaining section, As shown in Comparative Example Experiment No. 6 in Table 1, a coating layer having a thickness of 80 mm was provided by the soil containing only the segments.

After the completion of the construction, the rainfall conditions, the stabilized state of the guest soil layer, and the germination and growth conditions of the purpose were observed. The results are shown in Table 2.

Claims (2)

(57) [Claims] 1. A method for stabilizing a ground surface, comprising applying a soil containing a synthetic resin emulsion, fly ash and calcium hydroxide to the ground surface. 2. The method for stabilizing a ground surface according to claim 1, wherein a pH buffer is contained in the soil.