JPH0721190B2 - Ground surface stabilization method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention is suitable for use in preventing erosion and greening slopes and slopes of roads, river dikes, land reclamation sites, railways, etc. Regarding the stabilization method of the ground surface.

(Prior Art) An exposed ground surface such as soil or rock or soft rock is easily eroded by rain, wind, frost, etc., and preferably stabilized by a greening method. In particular, a relatively thick coating layer is formed by spraying the soil mixed with synthetic resin emulsion such as vinyl acetate on slopes where it is difficult to grow plants, such as bedrock, soft rock, and soil-free material. Thick layer soil stabilization method is often used.

However, when spraying such soil, the thicker the coating layer, the more days it takes for the soil to solidify and settle. Therefore, if there is rainfall when it is undried, the soil will often run out and collapse. . A method of rapidly solidifying the soil by using cement as a solidifying agent has been proposed, but
With this method, the alkalinity of the cement inhibits seed germination.

Then, a construction method using a soil containing gypsum is proposed in JP-A-60-137212. According to this method, although the soil is effective for early solidification, the soil is likely to dry and the water retention is poor. Therefore, the seeds may die especially in the early stage of germination due to drought damage.

(Problems to be Solved by the Invention) As a result of intensive studies to solve the above-mentioned problems in the conventional soil stabilization method, the present inventors have made the soil include gypsum and fly ashes, and preferably The present invention has been accomplished by finding that the incorporation of a synthetic resin emulsion, a pH buffer, or seeds or rhizomes improves the germination rate of seeds and improves plant growth.

(Means for Solving the Problems) The ground surface stabilization method according to the present invention is characterized in that the soil containing calcined gypsum and fly ash is applied to the ground surface.

In the present invention, it is advantageous that the synthetic resin emulsion is added to the soil. By using such a soil, it is possible to enhance the connectivity of the soil particles and prevent the soil from flowing out due to rainfall.

Further, 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 has excellent air permeability and water absorption and water retention, and further, it has flexibility suitable for germination and growth of plants. It can be performed advantageously.

Further, in the present invention, it is advantageous that the pH of the soil is adjusted to a range suitable for germination of plants and that a pH buffering agent having an action of aggregating the synthetic resin emulsion is contained. By using such a soil, the germination rate of seeds is improved and the plants grow well. As the pH buffering agent, aluminum sulfate, superphosphate or the like is preferably used, usually, the total amount of calcined gypsum and fly ash 100
The amount is 5 to 9 parts by weight, preferably 6 to 8 parts by weight with respect to parts by weight. When the amount of the pH buffer compounded is too small, the above-mentioned effects cannot be expected, while when it is too large, the germination rate of the plant tends to decrease, or the growth failure after germination tends to occur. Because.

In the present invention, as the synthetic resin emulsion, polyvinyl acetate, vinyl acetate-acrylic acid ester copolymer, styrene-butadiene copolymer, emulsion such as polychloroprene is preferably used, but among them,
Polyvinyl acetate emulsion is preferably used because it has an excellent effect of enhancing the binding property of the soil particles and is inexpensive.

These synthetic resin emulsions, when too much, excessively harden and solidify the soil, or the synthetic resin coating coats the soil particles and impairs water absorption and air permeability, so seeds mixed in soil. And lead to germination disorders of the rhizome. On the other hand, when the amount is too small, it is difficult to bond the particles of soil to the soil, and the soil to soil is poor in water absorption and water retention. Therefore, for example, even after drying, it is easily eroded by rainfall and becomes a mudflow state, and is likely to collapse. Therefore, in the present invention, the synthetic resin emulsion is used as the synthetic resin in the range of 1 to 10% by weight of the soil.

The calcined gypsum and fly ashes as the binder are not particularly limited because they depend on the soil used.
Usually, it is used in the range of 3 to 8% by weight of the soil. When the amount of baked gypsum and fly ashes is too small,
The hardening effect is poor and the soil cannot be solidified in a short time. However, when it is added in an excessive amount, the soil soil becomes too hard, which may lead to seed germination disorders.

Further, the preferred mixing ratio of the calcined gypsum and fly ash is in the range of 25:75 to 75:25, more preferably,
The range is from 30 to 70 to 70 to 30. If the amount of calcined gypsum is too large, it will cause the surface layer of the soil to dry and crack, contributing to the collapse and outflow of the soil. If the amount of fly ashes is too large, the water retention is too high and the solidification property of the soil becomes poor.

The soil used in the present invention is generally an organic material, peat moss, bark compost, wood cellulosic fibers, etc. after mixing and dispersing the gypsum and fly ash, and if necessary, diluting the synthetic resin emulsion with water. It can be obtained by further mixing and mixing, and if necessary, adding a pH buffer, seeds or rhizomes, 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 carried out by a general seed spraying method (spraying method), and also on slopes such as bedrock and soft rock. The pressure spraying method may be used.

(Effect of the invention) As described above, according to the method of the present invention, since the fly soil is contained in the soil along with the calcined gypsum, the soil is excellent in water retention and water retention, and seeds do not cause germination damage. ,
Furthermore, by including a pH buffer in the soil, the germination rate of seeds is improved and the plants grow well.

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

Example Based on the composition of the soil used in the present invention based on 200 parts by weight of peat moss (1 m ³ ), the number of parts by weight is as shown in Table 1, and the calcined gypsum, fly ash, and, in some cases,
Synthetic resin fat emulsion (concentration 50% by weight) and pH buffer were added and uniformly kneaded to prepare the soil.

A slate plate is installed by inclining it at an angle of 35 ° with respect to the horizontal plane, and the slate plate with an area of 1000 cm ^{2 has} a thickness of 100% with the above soil.
Established a mm soil layer. After curing this for 4 hours or 24 hours, artificial rain of 5 mm per minute was applied for 30 minutes, and the runoff soil layer was examined. The results are shown in Table 1.

Separately, the soil was prepared in the same manner as described above except that whipping glass, white clover, and Kentaki 31 fuesque were mixed as seeds into the soil, and a soil layer was provided on the slate plate. At that time, the upper soil layer was sowed to leave a thickness of 5 to 10 mm, and the soil for covering was left sowing.
The germination rate 30 days after sowing was examined. The number of grains of each seed was 100. The results are shown in Table 1.

The abbreviations for synthetic resin emulsions in Table 1 are as follows.

PVAc: Polyvinyl acetate Et / VAc: Ethylene-vinyl acetate copolymer VAc / Ac: Vinyl acetate-acrylic acid ester copolymer St / Ac: Styrene-acrylic acid ester copolymer Comparative example Synthetic resin for comparison A soil containing neither emulsion, gypsum, or fly ashes (Experiment No. 1),
Soil containing only gypsum as a solidifying agent (Experiment No. 2
5), using the soil soil containing only cement as a coagulant (Experiment No. 6), the amount of soil soil discharged 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.

Further, for comparison, using commercially available powdery soils (Experiment Nos. 7 and 8) containing no synthetic gypsum and fly ashes, but containing only synthetic resin emulsion (Experiment No. 7 and 8), respectively, in the same manner as in Examples, The amount of soil discharged and the germination rate of seeds were investigated. The results are shown in Table 1.

Claims (3)

[Claims] 1. A method for stabilizing a ground surface, which comprises applying a soil containing gypsum and fly ash to the ground surface. 2. The ground surface stabilization method according to claim 1, wherein the soil contains a pH buffering agent. 3. The ground surface stabilization method according to claim 1 or 2, wherein the soil contains seeds or rhizomes.