JP7175827B2 - Slope protection layer and slope protection method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a slope protection layer formed by using shells and the metabolic action (microbial reaction) of microorganisms, and a slope protection method.

Conventional methods for protecting the slope include fixing a slope protection mat to the slope (see Patent Document 1), stacking stone baskets to protect the slope (see Patent Document 2), and using wall materials to protect the slope. It is known to fix (see Patent Document 3).

JP 2008-208604 A JP 2015-45133 A JP 2012-184605 A

In the conventional slope protection and slope protection method described above, there is a problem that material costs and construction costs are high, and resource saving and cost reduction cannot be achieved.
SUMMARY OF THE INVENTION It is an object of the present invention to provide a slope protection layer and a slope protection method that can utilize seashells, which are waste, to achieve resource saving and cost reduction.

According to the slope protection layer according to the present invention, it is characterized in that it is formed by supplying crushed shells obtained by pulverizing unfired shells and microorganisms to the slope, so that waste shells can be used. Therefore, resource saving and cost reduction can be realized.
In addition, according to the method for protecting a slope according to the present invention, it is characterized in that pulverized shells obtained by pulverizing unfired shells and microorganisms are supplied to the slope. Resource saving and cost reduction can be realized.
In addition, since crushed scallop shells are used as the crushed shells, scallop shells, which are a waste product, can be used, and resource saving and cost reduction can be realized.
In addition, the slope is a slope formed by an embankment, and the embankment is constructed by alternately stacking a solidified layer of pulverized shells formed by supplying pulverized shells and microorganisms and a layer of earth and sand. Since the slope protection layer formed on the slope and the solidified layer of crushed shells are connected to each other, the embankment has excellent water permeability and water resistance and has good drainage, It becomes possible to build embankment land with excellent collapse prevention effect.

Sectional drawing which shows the procedure of the slope protection method (Embodiment 1). Sectional drawing which shows the embankment developed land (Embodiment 3). 4 is a diagram showing the component ratio of each specimen used in Experiment 1. FIG. Numerical table showing experimental results of Experiment 1. FIG. 7 is a graph showing experimental results of Experiment 1; The figure which shows the component ratio of each test body used for Experiment 2. FIG. 7 is a graph showing experimental results of Experiment 2; Numerical table and graph showing experimental results of Experiment 2. FIG.

Embodiment 1
As shown in FIG. 1, the slope protection layer 1 according to Embodiment 1 is formed by supplying crushed shells obtained by crushing unfired shells and microorganisms to the slope 2 .
In addition, the slope protection method according to the first embodiment for forming the slope protection layer 1 is to provide the slope protection layer 1 by supplying crushed seashells obtained by pulverizing unfired shells and microorganisms to the slope 2. formed.

The slope refers to an artificially sloped surface created by cutting or filling soil, or a naturally sloped surface.
In addition, crushed shells include fragments formed by crushing (breaking) shells into approximately equal sizes, coarse particles formed by crushing shells into coarse particles with a large particle size, and crushing shells into powder. It refers to powders etc. formed by

An unfired shell is an inorganic-organic composite consisting of about 95% by mass of inorganic components and about 5% by mass of organic components. The inorganic component is calcium carbonate, and the organic component is composed of a protein called conchiolin and chitin. be done.
The structure of the unfired shell is a laminated structure in which an organic sheet exists as a binder between the plate-like calcium carbonate layers, and the calcium carbonate layer and the organic sheet are bonded.

Therefore, by supplying unburned crushed shells and microorganisms to the slope soil, carbon dioxide (carbonate ions) generated by the metabolic action of microorganisms and calcium carbonate in the unburned crushed shells Calcium carbonate is precipitated between the particles of the crushed shells due to the mineralization reaction that reacts with calcium ions, and the bonds between the particles of the crushed shells (calcium carbonate layers) become stronger, and the crushed shells are bonded to each other. It is considered that a solidified layer of crushed shells is formed.
Furthermore, carbon dioxide produced by the metabolic action of microorganisms reacts (mineralization reaction) with calcium ions present in the soil or supplied to the soil, and carbonates precipitate between soil particles. It is thought that the soil is solidified by
That is, when the unburned pulverized shells and microorganisms are supplied to the soil, the synergistic effect of the solidification of the pulverized shells and the solidification of the soil forms a slope protection layer 1 that is highly effective in preventing slope collapse. it is conceivable that.

Specifically, the slope protection layer 1 may be formed through the steps shown in FIGS. 1(a) and 1(b).
(1) Spreading Mixed Material Step As shown in FIG. 1( a ), a mixed material 3 prepared by mixing unbaked scallop shell pulverized material and a yeast solution is spread evenly on the slope 2 .
The mixed material 3 may be prepared by mixing the pulverized scallop shells and the yeast liquid at a plant, site, or the like.
Also, the yeast liquid may be prepared by dissolving yeast (microorganisms) and glucose (a nutrient source metabolized by the microorganisms) in pure water, for example.
In addition, as can be seen from the experimental results described later, the crushed scallop shells are crushed scallop shells having a size corresponding to the size of the soil particles of the slope soil, preferably the soil particles of the slope soil. It is preferable to use crushed scallop shells having a size equal to or smaller than the particle size.
Specifically, it is preferable to supply the soil with pulverized scallop shells having a size equal to or smaller than the particle size of the soil particles of the soil on the slope and the microorganisms.
For example, when the soil on the slope is clayey soil such as red clay, it is preferable to supply the clayey soil with powdery pulverized scallop shells and microorganisms.
(2) Rolling Compaction Step As shown in FIG. 1(b), the slope protection layer 1 is formed by rolling the mixed material 3 spread evenly on the slope 2 with a roller compacting machine (not shown).
Therefore, the synergistic effect of the solidification of the pulverized scallop shells and the solidification of the soil of the slope 2 forms the slope protection layer 1 having a high slope collapse prevention effect.

Since the slope protection layer 1 formed according to Embodiment 1 is formed using scallop shells, which are waste, resource saving and cost reduction can be realized. That is, it is economical because unburned scallop shells, which have become waste, can be recycled. In addition, since it is used in an unfired state, there is no cost associated with firing, cleaning, etc., and it is economical.

As can be seen from the experimental results to be described later, the slope protection layer 1 formed according to Embodiment 1 is solidified by binding the pulverized scallop shells together, and is more firmly bonded to the soil of the slope 2. The ground scallop shell solidified layer has a high strength, and the support strength of the soil on the slope 2 is also increased, so that the slope protection layer 1 has a high slope collapse prevention effect.
In addition, the crushed scallop shell solidified layer that forms the slope protection layer 1 is a porous body with many gaps between the crushed scallop shells, and has excellent water permeability and water resistance. The slope protection layer 1 is highly effective in preventing collapse.

According to the slope protection method according to the first embodiment, the pulverized scallop shells are bonded together and solidified, and the pulverized scallop shell solidified layer with high supporting strength that is more firmly bonded to the soil of the slope 2 In addition, since the support strength of the soil of the slope 2 is increased, the slope protection layer 1 having a high slope collapse prevention effect can be formed.

Embodiment 2
In Embodiment 1, the mixed material 3 prepared by mixing the pulverized scallop shells and the yeast liquid is spread evenly on the slope 2, but the pulverized scallop shells, the yeast liquid and the earth and sand are mixed. The prepared mixed material may be spread evenly on the slope 2 .
As the earth and sand, for example, mountain sand, red soil, or the like used in the experiments to be described later may be used.

According to the second embodiment, by mixing the earth and sand, as can be seen from the experimental results described later, the crushed scallop shells and the earth and sand are more firmly bonded to form a solidified layer of crushed scallop shells with high supporting strength. As a result, the slope protection layer 1 is excellent in water permeability and water resistance and highly effective in preventing slope collapse.

Embodiment 3
As shown in FIG. 2, when the slope 2 is formed by an embankment 10, the embankment 10 is a solidified layer of pulverized shells formed by supplying pulverized scallop shells and microorganisms. 4, Alternatively, the pulverized shell solidified layer 4 formed by supplying pulverized scallop shells, microorganisms and earth and sand, and the earth and sand layer 5 may be alternately laminated.
Then, the slope protection layer 1 described in the first or second embodiment is formed on the slope 2 of the embankment 10 constructed in this way.
According to the method according to the third embodiment, the embankment 10 is constructed by alternately laminating the crushed shell solidified layer 4 and the earth and sand layer 5, so the slope formed on the slope 2 of the embankment 10 Since the protective layer 1 and the plurality of crushed shell solidified layers 4, 4 ... of the embankment 10 are connected, the embankment 10 is excellent in water permeability and water resistance and drains well, and the embankment is excellent in the effect of preventing collapse. Can build land.

Although yeast is exemplified as a microorganism, other microorganisms may be used.
Moreover, although glucose was exemplified as a nutrient source metabolized by microorganisms, other nutrient sources may be used.

Moreover, if the crushed scallop shell contains water, it is not necessary to supply water.
Further, when the soil of the slope 2 contains water, nutrients, etc., only the unburned pulverized scallop shells and microorganisms may be supplied to the soil.

Further, as described above, it is preferable to supply the unbaked scallop shell pulverized product, microorganisms, and a nutrient source such as glucose metabolized by the microorganism to the slope 2, but the nutrient source is not necessarily supplied. I don't mind. For example, it is possible to simply supply cultured and activated microorganisms and unburned crushed shells.

Moreover, it is preferable to supply the slope 2 with calcium nitrate, calcium chloride, or the like containing calcium ions, because this promotes the mineralization reaction.

Moreover, if a pH adjuster is supplied to the slope 2, the mineralization reaction in which carbonate ions and calcium ions generated by microbial reaction react with each other can be promoted, and favorable soil improvement effects can be obtained.
That is, the pH environment of the soil for promoting the mineralization reaction in which carbonate ions and calcium ions generated by the microbial reaction react is preferably pH 8 to 9. Alternatively, by maintaining the pH environment of the soil at pH 8 to 9 using a mixed fertilizer in which minerals and calcium hydroxide are mixed, it is possible to promote mineralization reactions and obtain favorable soil improvement effects.

In the above, an example of using a scallop shell pulverized product as the unbaked shell pulverized product is shown. may be used.

In the present invention, "supplying crushed shells obtained by crushing unfired shells and microorganisms onto the slope" means supplying a mixture of crushed shells and microorganisms to the slope 2. Alternatively, it refers to separately supplying the crushed shells and the microorganisms to the soil.
In addition, "supply" means supplying crushed shells and microorganisms to the surface of the slope 2, supplying them into the soil of the slope 2, or mixing them into the soil of the slope 2. say.

Experiment 1
An experiment was conducted to confirm the difference in supporting strength of the crushed shell solidified body formed by the difference in the size of the crushed shell.
As the crushed shells, the crushed shells of unbaked scallops were used.

As shown in FIG. 3, the following specimens were used.
- Specimen 1 was prepared by supplying 350 g of coarse-grained crushed scallop shells with 8 g of calcium nitrate and 150 ml of yeast solution. 350 g of the coarse-grained scallop shell pulverized product is 80-90% of the pulverized scallop shell with a particle size of 10 mm to 2 mm + 10-20% of the pulverized scallop shell with a particle size of 0.85 mm to 0.1 mm, and the coarse particles As the crushed scallop shells, the trade name "scallop chips" manufactured by Aomori Eco Cycle Industry Cooperative Company was used.
- Specimen 2 was prepared by supplying 8 g of calcium nitrate + 150 ml of yeast solution to 350 g of medium-sized pulverized scallop shells. 350 g of the medium-particle pulverized scallop shell contains 55 to 60% pulverized scallop shells with a particle size of 2 mm to 0.85 mm and 40 to 45% pulverized scallop shells with a particle size of 0.85 mm to 0.005 mm. As the scallop shell pulverized material of medium particles, the trade name "Scallop de Genki" manufactured by Aomori Eco Cycle Industry Cooperative Company was used.
- Specimen 3 was prepared by supplying 400 g of pulverized scallop shell powder and 8 g of calcium nitrate + 150 ml of yeast solution. 400 g of the powdery scallop shell pulverized product is 100% scallop pulverized product with a particle size of 0.106 mm to 0.005 mm, and the powdery scallop pulverized product is a product name “Scallop Marker”, Aomori I used a product made by Eco Cycle Industry Cooperative.
150 ml of the yeast liquid was prepared by dissolving 8 g of yeast and 8 g of glucose in pure water.
Further, each of test specimens 1, 2, and 3 was prepared by spreading scallop shell pulverized material on the bottom of a predetermined container to a depth of 20 mm, and then pouring 150 ml of yeast solution.
Then, each test body 1, 2, 3 is left in a room temperature environment (temperature 30 ° C., humidity 60%) for several days, and the supporting strength of each test body 1, 2, 3 is increased every day. I measured the situation.
The supporting strength was measured using a Yamanaka hardness tester.

Experimental Results As can be seen from FIG. 4 and FIG. 5, each of the specimens 1, 2 and 3 solidified and, in particular, the specimen 2, in which yeast was fed to the medium-grained scallop shell pulverized material, showed support after 3 days. It was possible to obtain a solidified shell pulverized product with a high supporting strength of 117.1 N/mm ² .

Experiments have demonstrated the fact that 150 ml of a yeast solution prepared by dissolving 8 g of yeast and 8 g of glucose in pure water can be supplied to crushed unbaked scallop shells to solidify the crushed scallop shells. rice field.

The reason why the pulverized scallop shells could be solidified as in the experiment is that, firstly, by supplying microorganisms to the pulverized shells obtained by pulverizing unbaked shells, the scallops are produced by the metabolic action of the microorganisms. Calcium carbonate is precipitated between the particles of the crushed shells due to the mineralization reaction in which carbon dioxide (carbonate ions) in the unburned crushed shells reacts with calcium ions other than calcium carbonate in the crushed shells. It is thought that the bond between the calcium carbonate layers became stronger, and the crushed shells were bonded together to form a solidified crushed shell material.
Secondly, in the experiment, microorganisms were supplied to the shell pulverized product obtained by pulverizing unburned shells, and calcium nitrate was supplied. The mineralization reaction that reacts with is accelerated and calcium carbonate is precipitated between the particles of the crushed shells, so that the bonds between the particles of the crushed shells (calcium carbonate layers) become stronger, and the crushed shells are combined to form a solidified shell pulverized material.

In particular, as in test sample 2, the crushed scallop shells are medium particles (for example, crushed scallop shells with a particle size of 2 mm to 0.85 mm are 55 to 60% + crushed scallop shells with a particle size of 0.85 mm to 0.005 mm is 40 to 45%), the gaps between the middle particles of the pulverized scallop shell become dense, the bonds between the calcium carbonate layers become stronger, and the solidified pulverized shell material with high supporting strength is formed. Conceivable.
In addition, like the test sample 1, the crushed scallop shells are coarse particles (for example, crushed scallop shells with a particle size of 10 mm to 2 mm 80 to 90% + crushed scallop shells with a particle size of 0.85 mm to 0.1 mm 10 to 20 %), the gaps between coarse particles of the pulverized scallop shells are large, so the bonding between the calcium carbonate layers is weakened, and the supporting strength of the solidified pulverized shell material is not increased.
Furthermore, as in test sample 3, when the crushed scallop shells are powdery particles (for example, 100% crushed scallop shells with a particle size of 0.106 mm to 0.005 mm), the powdery particles of the crushed scallop shells themselves It is considered that the support strength of the solidified crushed shell material did not increase because the support strength of the solidified shell crushed material was weak.

Experiment 2
An experiment was conducted to confirm the difference in soil improvement effect based on the difference in soil and the difference in the size of crushed shells to be supplied.

As shown in FIG. 6, the following specimens were used.
1. The specimen name "mountain sand" was prepared by supplying 400 g of mountain sand with 8 g of calcium nitrate + 150 ml of yeast solution + a pH adjuster (0.5 g of calcium carbonate + 19.5 g of mineral).
2. The specimen name "red soil" was a specimen obtained by supplying 350 g of red soil with 8 g of calcium nitrate + 150 ml of yeast solution + a pH adjuster (0.5 g of calcium carbonate + 12.0 g of mineral).

3. The test specimen name "mountain sand + sail" was a test specimen in which 400 g of mountain sand was supplied with 40 g of medium-grain crushed scallop shell + 8 g of calcium nitrate + 150 ml of yeast solution + pH adjuster (0.5 g of calcium carbonate + 19.5 g of mineral). .
4. The test specimen name "mountain sand + sail powder" was a test specimen in which 400 g of mountain sand was supplied with 40 g of ground scallop shell powder + 8 g of calcium nitrate + 150 ml of yeast solution + pH adjuster (0.5 g of calcium carbonate + 1.5 g of mineral). .
5. The specimen name "mountain sand + sail rough" was obtained by supplying 380 g of mountain sand with 80 g of coarse-grained (fragmented) crushed scallop shells + 8 g of calcium nitrate + 150 ml of yeast liquid + pH adjuster (0.5 g of calcium carbonate + 5.5 g of mineral). It was used as a test body.

6. The specimen name "red clay + sail powder" was prepared by supplying 200 g of red clay with 100 g of pulverized scallop shell powder + 8 g of calcium nitrate + 150 ml of yeast solution + pH adjuster (0.5 g of calcium carbonate + 12.0 g of mineral).
7. The specimen name "red clay + sail" was prepared by supplying 200 g of red clay with 100 g of ground scallop shells of medium size + 8 g of calcium nitrate + 150 ml of yeast solution + pH adjuster (0.5 g of calcium carbonate + 12.0 g of mineral).
8. The test specimen name "Red clay + Hoara" is a test specimen in which 200 g of red clay is supplied with 100 g of coarse-grained (fragment-like) ground scallop shells + 8 g of calcium nitrate + 150 ml of yeast liquid + pH adjuster (0.5 g of calcium carbonate + 12.0 g of mineral). and

The mountain sand had a particle size of about 5 mm to 0.125 mm, and was manufactured by Nakajima Gravel under the trade name of "Yamasuna".
The red soil (clay soil) has a particle size of about 0.074 mm to 0.005 mm, and is manufactured by Nakajima Gravel under the trade name of "Yamasuna".
The crushed scallop shells used were crushed scallop shells obtained by crushing unbaked scallop shells.
The medium-grain scallop shell pulverized product contains 55 to 60% pulverized scallop shells with a particle size of 2 mm to 0.85 mm and 40 to 45% pulverized scallop shells with a particle size of 0.85 mm to 0.005 mm. Named "Scallop de Genki", made by Aomori Eco Cycle Industry Cooperative.
The powdery crushed scallop shells were 100% crushed scallop shells with a particle size of 0.106 mm to 0.005 mm, and were manufactured under the trade name of "Scallop Marker" manufactured by Aomori Eco Cycle Industry Cooperative.
The coarse-grained (fragment-shaped) scallop shell pulverized material is 80 to 90% of the pulverized scallop shells with a particle size of 10 mm to 2 mm + 10 to 20% of the pulverized scallop shells with a particle size of 0.85 mm to 0.1 mm. , trade name "Scallop Chip", manufactured by Aomori Eco Cycle Industry Cooperative.
The above-mentioned Minekal, which is a converter lime fertilizer as a pH adjuster, was used under the trade name of "Kumiai Minekal" manufactured by Sangyo Shinko Co., Ltd.
The aforementioned Keical, which is a slag siliceous fertilizer as a pH adjuster, was used under the trade name of "Kumiai Keikaru" manufactured by Murakashi Lime Industry Co., Ltd.
150 ml of yeast liquid was prepared by dissolving 8 g of yeast and 8 g of glucose in pure water.
In addition, the test specimen using mountain sand was prepared by spreading mountain sand or mountain sand and pulverized scallop shells on the bottom of a predetermined container to a depth of 40 mm, and then pouring 150 ml of yeast solution. did.
In addition, a test body using red clay (clay) is prepared by spreading red clay or red clay and pulverized scallop shells on the bottom of a predetermined container to a depth of 10 mm, and then pouring 150 ml of yeast solution. did.
Then, each test piece was allowed to stand in a room temperature environment (temperature of 30° C., humidity of 60%) for 7 days, and the support strength of each test piece was measured every day.
The supporting strength was measured using a Yamanaka hardness tester.

・Experimental results Fig. 7 shows the results of changes in supporting strength obtained with the passage of time for the specimens to which no pulverized shells were supplied, that is, the specimens named "Yamasuna" and "Red soil" in Fig. 6. show.
As can be seen from the graph shown in FIG. 7, the test specimens "mountain sand" and "red soil", which were only supplied with yeast liquid without supplying crushed shells, did not provide sufficient supporting strength, which was expected. No soil improvement effect was obtained.

Specimens "mountain sand + sail (medium)", specimen "mountain sand + sail (powder)", specimen "mountain sand + sail (coarse)" in which pulverized shells of different sizes were supplied to mountain sand , and, to the red clay, the specimens "red clay + sails (powder)", "red clay + sails (medium)", and "red clay + sails (rough)" supplied with crushed shells of different sizes. Figure 8(a) shows numerical values indicating the transition of the supporting strength obtained over time, and Figs. 8(b) and 8(c) show graphs showing the transition of the supporting strength.

As can be seen from FIGS. 8(a) and 8(b), the test specimens "mountain sand + sail (medium)", "mountain sand + sail (powder)", and "mountain sand + sail (coarse)" are In both cases, on the 5th day, an excellent soil improvement effect was obtained in which the supporting strength was up to 117.1 N/mm ² .

In addition, as can be seen from FIGS. 8(a) and (c), the specimen “red soil + sail (powder)” is remarkably excellent in that the supporting strength reaches up to 480.6 N / mm ² on the third day. It was found that the soil improvement effect was obtained.

The reason why the above-mentioned soil improvement effect was obtained is, firstly, by supplying unburned crushed shells and microorganisms to the soil, carbon dioxide (carbonate ion) generated by the metabolic action of microorganisms and Calcium carbonate is precipitated between the particles of the crushed shells due to the mineralization reaction in which calcium ions other than calcium carbonate in the crushed shells in the unfired shell react, and the bonds between the particles of the crushed shells (interlayers of calcium carbonate) are formed. It is considered that the pulverized shells became stronger and solidified by binding the pulverized shells together to form a solidified body of pulverized shells.
Secondly, in the experiment, since calcium nitrate was supplied, the mineralization reaction in which the calcium ions in the calcium nitrate react with carbon dioxide generated by the metabolic action of microorganisms was promoted, and calcium carbonate was formed between the particles of the pulverized shells. is precipitated, the bonds between the particles of the crushed shells become stronger, and the crushed shells are bound together to form a solidified shell crushed product.
Third, carbon dioxide produced by the metabolic action of microorganisms and calcium ions present in the soil or calcium ions in the calcium nitrate supplied to the soil react (mineralization reaction) to form soil particles. It is thought that the soil solidified due to the carbonate precipitated between them.
In other words, it is considered that when the unfired pulverized shells and microorganisms were supplied to the soil, the synergistic effect of the solidification of the pulverized shells and the solidification of the soil improved the soil improvement effect.

In addition, mountain sand has a particle size of 5 mm to 0.125 mm, whereas powdery crushed scallop shells have a particle size of 0.106 mm to 0.005 mm, and medium-grain crushed scallop shells have a particle size of 2 mm to 0.005 mm, and coarse-grained (fragment-like) crushed scallop shells have a particle size of 10 mm to 0.1 mm.
That is, in the experiment, since the pulverized scallop shells having a particle size smaller than that of the mountain sand were supplied, the pulverized scallop shells entered between the particles of the mountain sand, and the bonding between the particles of the mountain sand became stronger. It is presumed that the soil became firm and had a large supporting strength.

In addition, while red clay has a particle size of 0.074 mm to 0.005 mm, powdery crushed scallop shells have a particle size of 0.106 mm to 0.005 mm. The crushed scallop shells having a diameter of 2 mm to 0.005 mm and coarse grains (fragments) have a particle size of 10 mm to 0.1 mm.

That is, the test sample "red clay + sail (powder)" has a size corresponding to the particle size of the red clay soil particles and the powder particle size of the pulverized scallop shell powder. In other words, since the particle size of the red soil particles and the particle size of the powder particles of the pulverized scallop shell are substantially the same (high), the minute intervals between the particles are equalized, It is thought that the mineralization reaction precipitated carbonates in the minute spaces between the equalized particles and hardened the red soil, solidifying the entire red soil as a whole and making the soil extremely strong.
That is, it was found from the experiment that the supporting strength of the soil can be improved by supplying the crushed scallop shells and microorganisms of a size corresponding to the size of the soil particles of the soil.

In addition, the powdery scallop shell pulverized material used in the experiment has a particle size of 0.106 mm to 0.005 mm, compared to medium-grain pulverized scallop shells and coarse-grained (piece-like) pulverized scallop shells. , Since it is presumed that it contains a large amount of powder with a particle size smaller than the upper limit of 0.074 mm of the red soil particle size, the powdery scallop shell crushed product easily enters between the red soil particles, It is presumed that as the bond became stronger, the entire red soil solidified as one, resulting in a soil with significantly greater bearing strength.

In particular, by adopting a method of supplying unfired crushed shells of a size corresponding to the size of the soil particles of the soil and microorganisms to the soil, a remarkably excellent soil improvement effect that can significantly improve the supporting strength can be obtained. found to be obtained.
For example, red soil, which is clay with a particle size of about 0.074 mm to 0.005 mm, is supplied with a powdery scallop shell crushed product with a particle size of 0.106 mm to 0.005 mm, that is, soil particles of soil By supplying crushed scallop shells smaller than the diameter and microorganisms to the red clay (soil), the powdery crushed scallop shells are more likely to enter between the red clay particles, and the bonds between the red clay particles are stronger. Therefore, it was found that a remarkably excellent soil improvement effect that can significantly improve the bearing strength can be obtained.

On the other hand, in the "red clay + sail (medium)" and "red clay + sail (coarse)" specimens, the particle size of the red soil particles differs greatly from the diameter of the pulverized scallop shells.
In other words, the gap between the red clay and the pulverized scallop shells is large, resulting in a disjointed arrangement. Therefore, it is considered that the bond between the red clay and the pulverized scallop shells was weakened, and the supporting strength was not obtained.

Therefore, from experiments, it was found that the supporting strength of soil can be improved by supplying ground scallop shells having a size equal to or smaller than the particle diameter of soil particles and microorganisms to soil.

In other words, when the soil is clayey soil, by supplying the powdery scallop shell crushed product and microorganisms to the clayey soil, the bearing strength of the clayey soil can be improved, and the soil improvement effect was found to be obtained.

1 slope protection layer, 2 slope, 4 crushed shell material solidified layer, 5 earth and sand layer.

Claims (4)

1. A slope surface protective layer, characterized in that it is formed by supplying crushed shells obtained by crushing unfired shells and microorganisms to a slope surface. 1. A method for protecting a slope, characterized in that pulverized shells obtained by pulverizing unfired shells and microorganisms are supplied to the slope. 3. The slope protection method according to claim 2, wherein crushed scallop shells are used as the crushed shells. The slope is a slope formed by an embankment, and the embankment is constructed by alternately stacking a solidified layer of pulverized shells formed by supplying pulverized shells and microorganisms and a layer of earth and sand. The slope protection method according to claim 2 or 3, characterized in that:

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