JP2819064B2 - Topsoil runoff prevention method by rainfall - Google Patents

Description

The present invention relates to a method for preventing runoff of topsoil due to rainfall from a bare land such as a construction site.

(Prior art) Recently, along with the active development of golf courses in mountain forests and wilderness, development of residential lands, construction of roads, land improvement, etc., topsoil has flowed out from bare land at those sites during heavy rains, and rivers and seas have been washed away. Pollution has become a major social problem of environmental destruction. In particular, in the Okinawa Prefecture region, a large amount of acidic topsoil called red soil flows out into the sea as the coast is dyed red, causing coral and seafood to die, and countermeasures have become an urgent issue. .

Conventionally, as a measure to prevent the pollution of the sea and rivers by red soil, a red soil sedimentation basin (sand basin) is provided at the end, the red soil particles are settled, and then the supernatant is overflowed. Since most of the particles are fine, it takes a long time for sedimentation, and in the event of heavy rain, it just escapes and eventually flows out, which is not effective in preventing red soil outflow.

For this reason, it has recently been called for to take measures against the source and to prevent the outflow of red soil during the rainy season, and the following methods have been adopted as a countermeasure.

The most common method of preventing topsoil runoff at the source is to spray mortar on the surface to cover the surface,
Alternatively, a method of covering a land surface with a high-molecular polymer, lime or an asphalt emulsion is known. However, these construction methods cover the land surface in a state where water does not penetrate, which hinders the growth of grasses and the like and causes secondary pollution. In particular, petroleum high molecular weight polymers do not corrode semipermanently and have many problems during restoration. Also,
These conventional methods not only impair the aesthetics after the construction, but also have a problem that the construction cost is high and the economic burden is high.

As described above, various construction methods have been proposed as measures to prevent topsoil runoff, but effective means have not yet been established.

(Problems to be Solved by the Invention) The present invention has been made in view of the above-mentioned circumstances, and solves the drawbacks of the conventional method for preventing topsoil outflow, and can effectively prevent outflow of topsoil, and It is an object of the present invention to provide a new topsoil runoff prevention method that promotes the growth of plants, can be easily constructed at low cost, and can be effectively applied to farmland and slopes.

(Means for Solving the Problems) As a result of various studies to solve the above problems, the present inventor has found that a soil is hardened by mixing an inorganic soil hardening agent and soil to form a slurry, and the site of the development site The present inventors have found that the surface can be easily condensed and hardened by spraying on the surface to prevent runoff of the topsoil due to heavy rain, and have reached the present invention.

That is, the method for preventing topsoil runoff due to rainfall according to the present invention is characterized in that a soil hardening agent and soil are mixed with water to obtain a matrix, and the matrix is sprayed onto the soil surface in the area to be treated to cover the topsoil.

By adopting an inorganic silica-based compound as the soil hardening agent, it also functions as a soil conditioner and promotes plant growth. Further, as the soil constituting the matrix, by adopting soil collected from the treated area, it is inexpensive in terms of cost, and also familiar with the soil at the site, without changing the properties of the soil It can be constructed effectively.

Furthermore, by stirring and mixing the plant fibers cut into a certain length into the matrix, the curing speed and the coating strength can be increased and the coating effect can be promoted. As plant fiber,
Appropriate materials such as plant fibers such as buds and straw or sawdust can be employed. And, by stirring and mixing the seeds of the plant with the matrix, planting work can be performed at the same time.

(Function) The matrix sprayed thinly on the surface of the treated area is hardened immediately after construction, and the penetration of water by rainfall is
Enhances matrix hydration and promotes soil hardening.
Therefore, construction can be performed in the rainy season regardless of construction conditions. And since the main component of a matrix is soil like a construction site, it is not conspicuous even after construction, and does not spoil the beauty of the surroundings.

By mixing the organic fibers, it is possible to prevent the hardening of the soil paste in which the organic fibers are thinly sprayed on the ground surface and to prevent the occurrence of cracks after the paste is dried and hardened, and to increase the self-shape retention during concentrated rainfall. Further, after the treatment, the soil mixed with the organic fibers is aggregated when cultivated, and becomes a soil conditioner suitable for planting. Therefore, the method for preventing topsoil runoff due to rainfall according to the present invention can effectively prevent runoff of topsoil such as red soil immediately after construction, and the hardened topsoil has excellent ventilation and aging of purchased organic fibers. , Which has the effect of promoting plant growth.

(Example) Hereinafter, an example of a method for preventing topsoil runoff due to rainfall according to the present invention will be described in detail.

The soil hardening agent used in the present invention is silicon dioxide 30 to 50.
%, Calcium chloride 30-45%, magnesium oxide 8-16
%, The main component of which is ferric chloride 3 to 8%, the matrix is neutralized to form a compound having a water density, and is excellent in the function of constituting a substance which is water resistant and can resist physical changes. ing. In the present embodiment, the component ratio is
%, Calcium chloride 38%, magnesium oxide 12%, ferric chloride 6% and other 6%. The soil hardener was diluted with water and used as a 20-30% solution.

The soil hardener solution, a suitable reaction accelerator such as quicklime, for example, and soil collected from the treated area, and plant fibers cut to an appropriate length are mixed with water in a mixer to form a slurry matrix. make. The matrix produced in this way is pumped to the area to be treated by a pressure pump, and is sprayed thinly on the surface to be treated with a spray gun at the tip thereof. Also, when mixing with a mixer, the seeds of the grass are also mixed at the same time, so that the seeds are sprayed on the surface of the ground in the sprayed state of the matrix thriller, which is suitable for vigor.

Example The following experiment was performed to confirm the operation and effect of this example.

Length × width × height = make a 120 mm × 200 mm × 50 mm of the basins, provided outlet for a one Kesho water at its bottom, its Masuichi cup, creating the experimental apparatus was filled with soil Sunawa 1.2 mm ^3. In addition, the matrix was created under the following conditions (each ratio is a ratio to 100% of soil).

Soil hardening agent 20% diluent 20% quicklime 10% water 30% Same kind of soil as the above-filled tub 100% 5-5mm cut buds 15% Thickness of matrix made by stirring and mixing the above ingredients But
When it was sprayed on the surface of the soil of the basin so as to have a thickness of 5 mm, it hardened after about 4 hours.

After that, a large amount of water was showered in the form of concentrated rain on the surface of the soil covered with the cured matrix, and after receiving the water flowing outward from the surface, the turbidity was observed,
Almost no turbidity due to soil runoff was observed. In addition, outflow of water was also observed from the water outlet, and it was confirmed that water had penetrated into the soil through the clothing layer.

Then, it was left for one month in the state, and there were three heavy rains during that time. However, the surface of the soil showed little change with only slight cracks, and no outflow of the topsoil was observed. Was.

After that, when the soil was plowed, it could be plowed very easily, and the plowed topsoil was in the form of granules, and a very air-permeable soil suitable for planting was obtained.

As described above, the construction method of the present invention is extremely effective in preventing topsoil outflow, and can be applied to any bare lands such as slopes, slopes, and agricultural lands.

Next, an example in which the present method is applied to a slope farmland will be described.

When the method is applied to agricultural land on a slope, vegetation ridges are formed along the contours of the slope, and the above-mentioned matrix is applied to one surface of the ridge on the sea side. In that case, if the matrix is not large enough to be sprayed by the pump, simply bring the soil hardening agent and reaction accelerator to the site, and in the container as appropriate at the site, place the soil at the site and the appropriate plant at the site A thriller-like matrix can be easily obtained by mixing the fibers with water. Then, the slurry can be easily and inexpensively dispersed by appropriately spraying the matrix on one surface of the ridge on the sea side.

When harvesting is completed, by cultivating together with the ridges, the coated matrix becomes a soil conditioner and has a combined effect on farmland. Thus, by repeating the above-mentioned construction every time the harvest is completed, it is possible to prevent the outflow of the topsoil from the sloping field.

(Effect) The method for preventing earth and sand runoff due to rainfall of the present invention has the above-described configuration and has the following special effects.

Immediately after construction, hardening progresses, and water infiltration due to rain increases the hydration reaction of the matrix, promotes soil hardening, can be applied even in the rainy season regardless of construction conditions, hardens topsoil and ensures runoff during heavy rain Can be prevented. And since the matrix which covers the surface of the to-be-processed ground is mainly made of soil, it is not noticeably integrated with the surrounding environment and does not impair the aesthetic appearance.

Also, since the soil hardening agent is an inorganic silica-based compound,
There is no risk of secondary pollution, and it is effective as a soil conditioner.

The main component of the matrix is soil, and it is possible to use soil collected from the treated area, so it is inexpensive and adapts well to the soil at the site and changes the properties of the soil It can be constructed effectively without any problems.

Furthermore, by mixing and mixing the vegetable fibers cut into appropriate lengths into the matrix, the curing speed and the self-shape retention force are increased, and the covering effect at the time of concentrated heavy rain is promoted. It promotes planting by promoting soil agglomeration.

And, by stirring and mixing the seeds of the plant with the matrix, the planting work can be performed simultaneously.

Claims (5)

(57) [Claims] 1. A method for preventing topsoil runoff due to rainfall, wherein a slurry-like matrix is obtained by mixing a soil hardening agent and soil with water, and the matrix is sprayed onto the soil surface in the area to be treated to cover the topsoil. 2. The method according to claim 1, wherein the soil hardening agent is an inorganic silica compound. 3. The method according to claim 1, wherein the soil constituting the matrix is soil collected from an area to be treated. 4. The method according to claim 1, wherein the matrix is mixed with plant fibers by stirring. 5. The method according to claim 1, wherein the matrix is mixed with plant seeds by stirring.