JP7027282B2 - Slope spray greening method and vegetation base material - Google Patents

Description

The present invention relates to a slope spraying greening method that makes it possible to omit the netting work by increasing the strength of the growth base to be created in the slope (including slope) greening in which the netting work is used together as the greening foundation work. In particular, the present invention relates to a vegetation base material spraying method (also referred to as a thick layer base material spraying method) that can omit the wire netting work (also referred to as lath tensioning work).

In the design and construction of slope greening work, except when the slope slope is gentle, it prevents the movement and slipping of the surface soil, keeps the growth base to be sprayed stable, and introduces plants and plants that are expected to invade. For the purpose of improving the growing environment, after constructing a netting work as a greening foundation work, it grows as a vegetation work by a spraying method such as a vegetation base material spraying work or a soil dressing spraying work (also called a soil dressing seed spraying work). The foundation is created.

In addition to these, there is a spray reinforced soil method in which long fibers called long fibers or continuous long fibers are mixed with sandy soil and sprayed on the slope. Although it depends on such a construction method and, strictly speaking, on the quality of the base material, if the vegetation base material is sprayed thickly to, for example, about 10 cm or more, the independence of the growth base is enhanced, so that the netting work may be omitted. Needless to say.

Here, netting is a method of stretching a net-like material on the ground, and is generally classified into wire netting and resin netting. Wire meshing has rigidity and is effective in preventing the movement and slipping of surface soil, maintaining the stability of the growing base to be sprayed, and preventing peeling due to frost heaving of slopes, so it is relatively relatively including cut slopes. It is widely used for greening steep slopes. On the other hand, the resin net upholstery is not rigid and it is difficult to deal with frost heaving and falling rocks, so it is often applied to embankment slopes with gentle slopes.

Here, the vegetation work is a method of introducing a plant, and is roughly classified into a sowing work, a planting work, and a vegetation induction work from the viewpoint of the aspect of the plant. The vegetation work can be roughly classified according to the mode of the construction method. One of them is the spray greening method (also called the mechanical construction method), which is classified into seed dispersal work, soil dressing spraying work, and vegetation base material spraying work. .. As a spraying greening method, a vegetation base material spraying method that can spray a growth base of 3 cm or more at a time even on a steep slope is widely adopted mainly on a cut slope.

Of these spraying greening methods, when applying soil dressing spraying work or vegetation base material spraying work to create a thick growth base, the combined use of netting work as a greening foundation work is standard for the reasons mentioned above, and it is rigid. Wire netting is commonly used.

However, in the case of vegetation base material spraying work, the cost ratio required for wire netting work is about 20% when the spraying thickness is 10 cm, about 33% when the spray thickness is 5 cm, and 41% when the spray thickness is 3 cm, which is the highest. In the actual situation, the cost ratio is as high as 30-40% for the thickness of 3-5 cm, which is thought to be frequently adopted. There is a need for a spray greening method that can be used.

As a method for increasing the strength of the growth base, a method disclosed in Patent Document 1 for improving the connectability of the growth base by mixing a short fiber material with the vegetation base material has been put into practical use. For example, the growth base is a short fiber material (polyvinyl alcohol-based fiber of synthetic fiber in the example) having a single fiber fineness of 0.7 to 120 denier and an aspect ratio of 120 to 1300, 0.2 to 6% by weight, bark. It contains 50% by weight or more of compost, 2 to 45% by weight of peat moss, and 0.1 to 25% by weight of a binder. As a result, it is possible to create a growth base that does not crack, collapse, fall off, or run off.

The weight of the growth base material varies depending on the material used and its water content. The vegetation base material spraying work "Slope Forest Chemical Method" (registration number: QS-980148-VE, publication period), which is a new technology utilization system (NETIS) registration technology in public works projects of the Ministry of Land, Infrastructure, Transport and Tourism, owned by the applicant. As an example, the total weight of the growth base is in the range of 124 to 154 kg / m ³ . Based on this, when converted to weight (rounded to the first decimal place), the mixing amount of the short fiber material is 0.2 to 6% by weight, which is at least 0.2 to 7.4 kg / m ³ , and at most 0.3 to 9. Since it is 2 kg / m ³ , it can be considered that the desired effect can be obtained by blending 0.2 to 9.2 kg / m ³ of the short fiber material.

As another method, Patent Document 2 describes water absorption with a fiber length of 5 to 20 cm in a growth base material prepared by mixing organic or inorganic materials, fertilizers, erosion-preventing materials and other compounding materials applied to the spray greening method. A growth base material characterized by containing 5 to 40% by volume of a fiber material having a property and a hygroscopic property (palm fiber in an example) is disclosed. As a result, a growth base that is durable against drying of the growth base after construction is realized.

In organic vegetation base material spraying work, the volume of the vegetation base material is generally consolidated by half by spraying to create a growth base, so 2000 L of growth base material is blended per 1000 L (liter) of finished product. do. Based on this, when the fiber material of the growth base material of Patent Document 2 is converted into volume, the blending amount of palm fiber 5 to 40% by volume is 100 to 800 L / m ³ . Since the bulk density of the loosened palm fibers is approximately 0.1, it can be considered that the desired effect can be obtained by blending 10 to 80 kg / m ³ of the palm fibers in terms of weight based on this. ..

Furthermore, the construction method of Non-Patent Document 1 is the vegetation base material spraying construction "non-lass construction method" (registration number: QS-020028, publication period has expired), which is the construction method owned by the applicant and omits the wire netting construction which is the NETIS registration technology. Yes, it has been developed and put into practical use by applying the techniques of Patent Document 1 and Patent Document 2. There are two types of construction methods in Non-Patent Document 1, one that uses synthetic resin staples and the other that uses natural staples. In recent years, natural staples that are friendly to the natural environment have been adopted at many sites. Has been done.

As yet another method, Patent Document 3 discloses a method for producing a recycled staple fiber material using the residual yarn of the spool paper tube. The residual yarn, which is a long fiber drawn from a plurality of spool paper tubes, is bundled and wound on a bobbin, and the residual yarn bundle wound on the bobbin is sequentially drawn out by a cutting device and cut to a predetermined length. By this manufacturing method, a recycled staple fiber material having a fiber length of 10 to 50 mm and an aspect ratio of 500 to 7000 can be obtained.

In Patent Document ³ , by blending 1 to 5 kg / m3 of polyester staple fiber in the growth base material, it is realized that cracks in the greening base created by spraying can be prevented or the cracks can be made inconspicuous. .. However, the effect of increasing the strength of mortar / concrete and growth base has not been obtained.

Japanese Unexamined Patent Publication No. 7-327484 Japanese Unexamined Patent Publication No. 10-113069 Japanese Unexamined Patent Publication No. 2013-238028 Japanese Unexamined Patent Publication No. 2004-225330

Yoshida and Furuta (2002) Vegetation base material spraying work omitting wire netting work, Journal of Japan Green Engineering Society 28 (1), 193-196.

The construction method (construction method name: non-lass construction method) of Patent Document 1 and Non-Patent Document 1 based on Patent Document 1 is 2 kg / m ³ when vinylon short fibers are used as standard specifications, and 8 kg / m when coconut fibers are used. It is a construction method that enhances the effect of connecting the growth base by mixing ³ and omits the wire netting work, and has been adopted in many sites so far.

However, when the construction is carried out under the location conditions located in the windy coastal area or the terrain that becomes the wind channel, the growth base may peel off, or the weeds that originally grew in the ground may sprout and the growth base may rise and peel off. There was a case of doing so. In order to make the conventional technique that can omit these netting works more reliable, the development of a method that further enhances the strength of the growth base and exerts the germination and growth promoting effect of plants equal to or higher than the conventional technique. Is required.

The present invention is most often adopted in the slope spraying greening method, particularly in the vegetation base material spraying method, when the plant is sprayed alone to a thickness of 3 to 10 cm without using an auxiliary method such as a buried fence. The purpose is to realize a growth base in which the strength of the growth base is enhanced even when sprayed to a thickness of about 3 to 5 cm to 3 to 7 cm, and the netting work can be omitted.

In order to achieve the above object, the present invention provides the following configurations.
-Aspect of the present invention is the vegetation base material used in the greening method in which the vegetation base material is directly sprayed on a slope without using a netting work as a greening foundation work.
It is a mixture containing at least a growth base material as a main material, a clay mineral, a first staple fiber material, and a second staple fiber material.
In the first short fiber material and the second short fiber material, the first short fiber material is relatively hard, the average fiber length is 4.5 cm ± 3.0 cm , and the second short fiber material is said. A vegetation base material characterized in that the fiber material is soft and the average fiber length is 2.0 cm ± 1.0 cm .
-Another aspect of the present invention is a slope spraying greening method using a vegetation base material without using a netting work as a greening foundation work.
A step of preparing a vegetation base material by mixing at least a growth base material as a main material, a clay mineral, a first staple fiber material, and a second staple fiber material.
It has a step of directly spraying the vegetation base material on a slope.
In the first short fiber material and the second short fiber material, the first short fiber material is relatively hard, the average fiber length is 4.5 cm ± 3.0 cm , and the second short fiber material is said. The fiber material is soft and the average fiber length is 2.0 cm ± 1.0 cm .

According to the present invention, in the slope spraying greening method in which the vegetation base material is sprayed on the slope without using the netting work (wire netting work) as the greening foundation work, the effect of enhancing the strength of the growth base and the resistance to the growth base are compared with the prior art. It is possible to create a growth base that is excellent in erosion-enhancing effect and durability-enhancing effect and is expected to have plant growth equal to or higher than that of the prior art.

As a result, the growth base is peeled off or originally grows in the ground when the construction is carried out under the location conditions that are located in the windy coastal area or the terrain that becomes the wind channel, which is a problem that the conventional technology had. The problem that weeds sprout and the growth base rises and peels off is solved.

Due to these effects, it is possible to reduce the risk of reworking the greening work and the risk of being forced to reconstruct the greening work according to the present invention.

FIG. 1 shows an experimental design table of Example 1. FIG. 2 is a table showing the survey results (vegetation coverage rate, community height, coverage / community degree) of Example 1. FIG. 3 is a table showing the results of the three-way ANOVA of Example 1. FIG. 4 is a graph showing a comparison of plant heights (two-way ANOVA) of Bahiagrass (BaH). FIG. 5 is a graph showing a comparison of Bahiagrass (BaH) densities (two-way ANOVA). FIG. 6 is a graph showing a comparison of the strength of the growth substrate (uniaxial compressive strength) when wet. FIG. 7 is a graph showing a comparison (bending strength) of the strength of the growth substrate at the time of drying. FIG. 8 is a graph showing a comparison of the amount of eroded soil during wet and dry conditions. FIG. 9 is a graph showing a comparison of drying shrinkage crack intervals (three-way ANOVA). FIG. 10 is a graph showing a comparison of drying shrinkage crack lengths (three-way ANOVA). FIG. 11 is a photograph comparing the peeling state of the growth base confirmed 105 days after the construction.

Hereinafter, embodiments of the present invention will be described with reference to examples.
The present invention relates to a greening method in which a vegetation base material is directly sprayed on a slope without using a netting work as a greening foundation work. The vegetation base material is a mixture containing at least a growth base material as a main material, a clay mineral, a first staple fiber material A, and a second staple fiber material B. In the first short fiber material A and the second short fiber material B, the first short fiber material A is relatively hard and the average fiber length is long, and the second short fiber material B is soft and average. It is characterized by a short fiber length.

A short fiber material A having an average fiber length longer than that of the short fiber material B and being hard is blended to have a shear resistance (connecting effect). Furthermore, by blending the clay mineral and the short fiber material B, which has a shorter average fiber length than the short fiber material A and is soft, the volume increase of the clay mineral caused by water absorption and the effective gap compression effect of the growth base due to the swelling pressure are obtained. A synergistic effect with the frictional force enhancing effect is obtained by entwining the short fiber material B with the short fiber material A in a state where the growth base material is interposed, and as a result, the strength, erosion resistance, and durability of the growth base material are obtained. And realized to enhance plant viability.

As the growth base material, in addition to bark compost and peat moss, compost products such as pruned branches and leaves, locally generated earth and sand, sandy soil, raw chips, composted chips, fermented sludge compost, etc. can be used. This method is classified as an organic vegetation base material spraying method that uses an organic growth base material such as peat moss as the main material, and is particularly effective.

Clay minerals are clays whose main material is silicate minerals, and bentonite, kaolinite, montmorillonite, sericite, talc, zeolite and the like can be used. The clay mineral used in the present invention may be any as long as it exhibits the effect of increasing the volume caused by water absorption and the effective gap compression effect of the growth base due to the swelling pressure, and bentonite widely used in civil engineering works is suitable. By mixing clay mineral with the growth base material, it absorbs water and fills the voids in the organic base material to increase the bonding force of the erosion prevention material, and also increases the frictional resistance between the mixed short fiber material and A and B. It works.

The short fiber material A is a fiber having an average fiber length longer than that of the short fiber material B and is hard, and has an effect of increasing the shear strength by dispersing it in the growth base to be sprayed. Short fiber material A is a fiber whose purpose is to increase the shear resistance of the growth base material and reinforce it. Steel fiber, stainless fiber, glass fiber, carbon fiber, ceramic fiber, aramid, nylon, vinylon, polyethylene, polypropylene, polyester. , Palm fiber, cellulose fiber, etc. can be used.

However, what is important here is that the short fiber material A does not reinforce structures such as mortar and concrete that solidify, but reinforces the growth base for greening where it is difficult to obtain peripheral frictional force due to the fibers. Due to its peculiarity, it is necessary to mix and disperse as long fibers as possible in the substrate. Therefore, the short fiber material A has a certain degree of hardness (waist) in the fiber, and the fiber surface is not smooth and has irregularities, or the fiber is bent rather than linear, and the fiber is contained in the growth base. Fibers that exhibit as strong a peripheral frictional resistance as possible when dispersed are desirable. Therefore, natural fibers in which the fibers are linear and the surface is not smooth as compared with chemical fibers are desirable, and palm fibers in which the fibers are bent are particularly preferable.

Further, since the short fiber material A is a relatively hard fiber, if the fiber length is long, the stirring efficiency is remarkably deteriorated due to the occurrence of rotation during stirring and mixing of various materials by the mixer, and the staple fiber material A is uniform in the vegetation base material. It becomes difficult to disperse in. It is preferable that the average fiber length of the staple fiber material A is in the range of 4.5 cm ± 3.0 cm so that the workability is not hindered and the staple fiber material A is uniformly dispersed in the vegetation substrate.

The short fiber material B is a fiber having an average fiber length shorter than that of the short fiber material A and is soft. By uniformly dispersing the short fiber material B in the growth base material to be sprayed, the short fiber material B is entangled with the short fiber material A and grows while interposing the growth base material. It has the effect of increasing the bonding force and shear resistance of the substrate and suppressing the occurrence of drying shrinkage cracks. In order to efficiently entangle the short fiber material B with the short fiber material A, it is important that the fiber length is shorter than that of the short fiber material A and the surface is smooth and soft. It is valid. The type of the chemical fiber is not particularly limited, but for example, the recycled staple fiber material of Patent Document 3 is a polyester having high strength among the chemical fibers, and is economically effective.

In order to efficiently entangle the short fiber material B with the short fiber material A having an average fiber length of 4.5 cm ± 3.0 cm, the average fiber length of the short fiber material B should be in the range of 2.0 cm ± 1.0 cm. Suitable.

The classification of whether each of the short fiber materials A and B is hard or soft depends on whether the short fiber material A and the short fiber material B are relatively soft or hard. Further, if the length of each of the short fiber materials A and B is shorter than the above-mentioned range, the desired effect is not remarkable, and if it is long, the workability is deteriorated.

As an example of the physical properties of the staple fiber material, the staple fiber A is preferably a natural fiber having an aspect ratio of 100 to 500, an elongation rate of 10 to 30%, and a tensile strength of 50 to 800 cN, and among them, an aspect ratio of 200 to 400 and an elongation rate. A coconut fiber having a tensile strength of 100 to 700 cN and a tensile strength of 10 to 30% is more suitable.

The short fiber material B is preferably a chemical fiber having an aspect ratio of 500 to 7000, an elongation of 30 to 100%, and a tensile strength of 1 to 30 cN, and further preferably an aspect ratio of 1000 to 3500, an elongation of 40 to 60%, and a tensile strength. Polyester fibers with an aspect ratio of 2 to 10 cN are more suitable.

In addition to these materials, erosion prevention materials (bonding materials), fertilizers, seeds, etc. are mixed in the same way as the normal slope spray greening method. There are two types of erosion prevention materials: synthetic resin typified by vinyl acetate resin and inorganic typified by cement. The material is suitable, and for example, the erosion-preventing material for an organic growth base material described in Patent Document 4 which does not inhibit the germination and growth of plants is effective.

[Other effects]
As a secondary effect of the present invention, there is a medium- to long-term strength enhancing effect of the growth base due to the entanglement effect of the root system of the plant, the short fiber material A and the short fiber material B introduced by the greening work. The present invention is characterized in that the strength of the growth base is enhanced from the state immediately after construction without the intervention of the plant root system. The strength-enhancing effect of this growth base was observed during the test construction conducted so far, and after the construction, the root system of the germinated plant was entwined with the staples A and B with the growth base material intervening and extended. It has been confirmed that this makes it difficult for the plant to be pulled out. Of course, the soil binding force of the root system is well known, but the present invention has a medium- to long-term base strength, erosion resistance, and durability of the growth base as the root system of the plant grows after construction, as compared with the prior art. It was suggested that it can be expected to enhance sex and exert a higher effect.

[About construction]
By blending short fiber materials A and B, which have relatively different average fiber lengths and hardness, in the growth base, the strength of the growth base is enhanced by the synergistic effect of the effective gap compression effect and the frictional force enhancing effect of the growth base. Therefore, it is important to sufficiently stir various materials at the time of construction to mix them uniformly.

In the spraying greening method, various materials may be directly put into a spraying machine and mixed, but in order to maximize the effect of the present invention, each material is represented by a shaftless mixer in advance. It is desirable to put it in a mixer with high stirring efficiency and mix it. In addition, it is necessary to mix water in order to obtain the bonding force of the erosion preventive material. At this time, the staple fibers A and B can be dispersed in the vegetation base material by sufficiently stirring and mixing with water in advance. There is no problem if the water is agitated by the shaftless mixer or after being added to the sprayer after stirring, and if the pumping distance of the vegetation substrate is long, the water is merged in front of the spray nozzle. It may be mixed.

The results of the test construction demonstrating the inventive step with respect to the prior art of the present invention are shown as examples.
[Example 1] Verification of plant growth by field test In completing the present invention, a basic test was conducted in advance of this example to determine a suitable blending amount of various materials suitable for plant growth. As a result, clay mineral (bentonite) is 5 to 50 kg / m ³ , short fiber material A (palm fiber) is 20 to 100 L / m ³ , and short fiber material B is a mixture of various materials that do not interfere with plant growth. It has been concluded that it is desirable to add 1 to 5 kg / m ³ of (polyester fiber).

Therefore, within the range of this compounding amount, in consideration of workability and economy, a test was conducted in which a more suitable upper limit value and lower limit value of the compounding amount were adopted. In this test, in order to reconfirm the plant growth by blending the short fiber material B, a test group was set up in which only the polyester staple fiber material was not blended.

In the test, in order to verify whether there is a problem in the viability of the plant as compared with the prior art (the method described in Non-Patent Document 1 based on Patent Document 1 and Patent Document 2), the prior art 1 (vinylon staple fiber) is used. And the prior art 2 (palm short fiber) are set, and for the method of the present invention, there are three factors I of clay mineral (bentonite), short fiber material A (palm fiber), and short fiber material B (polyester fiber). , II, and III were combined to perform a comparative test.

The construction was carried out using the construction machine actually used, and the growth base was sprayed on the 1.8m × 1.8m test plot set up in the experimental field in the Technical Center of Toko Geotech Co., Ltd. in Tochigi Prefecture. The experimental plan is as follows. In each test plot, organic growth base material (trade name: Olga Soil) 2000 L / m ³ , inorganic erosion preventive material (trade name: Remicontrol) 60 kg / m ³ , and seeds (Tall fescue) (TF), Creeping Red Fesk (CRF), Yamahagi, Sharinbai, Mallotus japonicus, Kihada, Oyamazakura) are common.

FIG. 1 shows an experimental design table of Example 1.
Conventional Technology 1: Vinylon Staples (Technology of Patent Document 1)
Conventional technique 2: Palm staple fiber (Technology of Patent Document 2)
The present invention: Three-factor experiment-Factor I: Clay mineral (bentonite),
Mixing amount (α1: 10 kg / m ³ , α2: 30 kg / m ³ )
・ Factor II: Staple fiber A (palm fiber, trade name: Remi fiber)
Mixing amount (β1: 40 L / m ³ , β2: 80 L / m ³ )
・ Factor III: Staple B (polyester fiber, trade name: Kiri fiber)
Mixing amount (γ1: 0 kg / m ³ , γ2: 1 kg / m ³ , γ3: 2 kg / m ³ )

The material composition per 1 m ³ of the prior art 1 is as follows.
Growth base material (organ soil) 2000L
Staple material (vinylon fiber) 2kg
Erosion prevention material (Remi Control) 60kg
Slow-release fertilizer (high control) 4 kg
1 set of seeds

The material composition per 1 m ³ of the prior art 2 is as follows.
Growth base material (organ soil) 2000L
Staple material (palm fiber) 80L
Erosion prevention material (Remi Control) 60kg
Slow-release fertilizer (high control) 4 kg
1 set of seeds

FIG. 2 is a table showing the survey results (vegetation coverage rate, community height, coverage / community degree) of Example 1.
As a result of the test, the vegetation coverage ratio after 11 months of construction was higher in the clay mineral ³⁰ kg / m3 compounding group and the short fiber material ^A80L / m3 compounding group than in the prior art 1 and the prior art 2, and the community height was also clay mineral 30 kg / m. The m3 compounding group was higher than the prior art ² and the conventional technique 2, and the coverage and group coverage of the plants were generally the same as or predominant in the control group 1.

From this result, it was confirmed that the vegetation base made of the material constituting the present invention is at least equivalent to that of the prior art, but rather has a growth promoting effect more than that.

FIG. 3 is a table showing the results of the three-way ANOVA of Example 1.
Next, a three-way ANOVA was performed on the tree height, plant height and density of the plant, and the effect of the blending amounts of clay mineral, short fiber material A, and short fiber material B was verified. As a result, no significant difference was observed in each factor except for some plants, and there was a mixture of positive and negative relationships with respect to the amount of compounding, and the compounding amount of each material tested and constructed. In the range of, it was confirmed that there was no problem considering that the viability of each plant was the same.

When the spraying work was performed in the test construction, the clay mineral 30 kg / m ³ compounding group had a larger spraying resistance than the 10 kg / m ³ compounding group, and the viscosity of the vegetation base material was clearly higher. .. Therefore, it can be said that 10 kg / m ³ of clay mineral is suitable in consideration of workability in the construction work.

[Example 2] Verification of plant growth on slopes Conventional technique 1 and book by rapid greening by exotic herbs on the east-facing and west-facing embankment slopes (slope length 15 m, gradient 1: 1.4) in Fukushima Prefecture. A comparative test of the invention was conducted. The material composition per 1 m ³ of the present invention in this test is as follows. The plants (seed) used are TF, CRF, Bermudagrass (BG), Bahiagrass (BaH), and Birdsfoot trefoil (BFT).
Growth base material (organ soil) 2000L
Staple A (palm fiber) 40L
Staple B (polyester fiber) 2 kg
Clay mineral (bentonite) 10 kg
Erosion prevention material (Remi Control) 60kg
Slow-release fertilizer (high control) 4 kg
1 set of seeds

In the vegetation two months after the construction, an exotic herbaceous plant community dominated by BaH with a coverage of 5 was formed on both the eastward slope and the westward slope, and the apparent vegetation coverage was 100%, and no difference was observed between the construction methods. rice field. The total density of introduced species reached 1,208 lines / m ² on the eastward slope and 992 lines / m ² on the westward slope, and it is considered that the type analysis is not very meaningful due to the influence of interspecific competition. Therefore, a two-way ANOVA was performed using the slope orientation (eastward and westward) and the applied method (previous technique 1, the present invention) to compare the plant height and density of the dominant species, BaH.

FIG. 4 is a graph showing a comparison of plant heights of BaH (two-way ANOVA).
Regarding the plant height, no difference was observed between the prior art 1 and the present invention, and it was confirmed that the present invention had the same growth characteristics as the prior art 1 as in the result of Example 1. rice field.

FIG. 5 is a graph showing a comparison of BaH densities (two-way ANOVA).
Regarding the density, a difference (p = 0.06) was observed with high probability between the prior art 1 and the present invention, and it was confirmed that the present invention has an effect of promoting the germination of plants.

[Example 3] Verification of strength-enhancing effect of growth base In order to verify the strength-enhancing effect of the present invention, the following comparative test was conducted.
Conventional Technology 1: Vinylon Staples (Technology of Patent Document 1)
Conventional technique 2: Palm staple fiber (Technology of Patent Document 2)
Invention 1: Staple material A + Staple material B 1 kg / m ³ compounded Invention 2: Staple material A + Staple material B 2 kg / m ³ compounded

The material composition of the prior art 1 and the prior art 2 is the same as that of the first embodiment. In addition, the material composition per 1 m ³ of the present invention in this test is as follows.
Growth base material (organ soil) 2000L
Staple A (palm fiber) 80L
Staple B (polyester fiber) 1kg and 2kg
Clay mineral (bentonite) 10 kg
Erosion prevention material (Remi Control) 60kg
Slow-release fertilizer (high control) 4 kg

The test was conducted using a construction machine that was actually used, and the vegetation substrate that had been sufficiently agitated with a shaftless mixer was packed in a plastic mold of φ5 cm × 10 cm to confirm the effect of enhancing the strength of the growth substrate in a wet state. A specimen for a uniaxial compression test was prepared. Furthermore, a vegetation base material is sprayed onto a plastic container having an inner size of 39.0 cm × 23.7 cm and a height of 7.0 cm, and a specimen for a bending test for confirming the effect of enhancing the strength of the growth base in a dry state is provided. Created. The specimen was cured indoors, and in the bending test, the substrate was removed from the plastic container and cut to a width of 10 cm to obtain the specimen.

The test method was divided into wet and dry. The growth base may shrink and deform as the material ages, and in such a state, it is for uniaxial compression test in which short fibers are mixed. Due to the difficulty in shaping the specimen.

FIG. 6 is a graph showing a comparison of the strength of the growth substrate (uniaxial compressive strength) when wet.
As a result of Tukey's multiple comparison test for the result of the uniaxial compression test (n = 9), the growth base when wet (water content ratio 160.6%) is the prior art 1, the prior art 2, and the short of the present invention. There was no difference between the amount of fiber material B blended at 1 kg / m ³ , but when short fiber material B was blended at 2 kg / m ³ , there was a high probability of both prior art 1 and prior art 2. A significant difference (the former p <0.01, the latter p = 0.08) was observed.

In addition, a significant difference (p <0.05) was also observed between the staple B compounding amount of 1 kg / m ³ and the compounding amount of 2 kg / m ³ , and the growth base was in a moist state, that is, after the construction. It was confirmed that the strength of the growth base can be improved by about 18% as compared with the case of using only the short fiber material A by blending 2 kg / m ³ of the short fiber material B even in the absence of the staple.

FIG. 7 is a graph showing a comparison (bending strength) of the strength of the growth substrate at the time of drying.
As a result of Tukey's multiple comparison test for the result of the bending test (n = 5), the growth base at the time of drying (water content ratio 35.9%) was between the prior art 1 and the prior art 2, and the present invention. It was confirmed that the short fiber material B compounding amount 1 kg / m ³ and the compounding amount 2 kg / m ³ were not significant and were equivalent.

Next, when the prior art and the present invention are compared, there is a significant difference between the prior art 1 and the short fiber material B compounding amount 1 kg / m ³ and compounding amount 2 kg / m ³ of the present invention (the former p <0. 01, the latter p <0.05) was observed, and the intensity was increased by 43 to 50%. Further, there is a high probability of a significant difference between the prior art 2 and the short fiber material B compounding amount of 1 kg / m ³ and the compounding amount of 2 kg / m ³ of the present invention (the former p <0.05, the latter p = 0. 11) was observed, and the intensity was increased by 30 to 37%.

From the results shown in FIGS. 6 and 7, by combining the staple fiber material A and the staple fiber material B, the strength of the growth base is greatly improved when dried as compared with the case where the staple fiber material A alone is used. It was confirmed that it could be done.

[Example 4] Verification of erosion resistance enhancing effect of growth base In order to verify the strength enhancing effect of the growth base of the present invention, the following comparative test was conducted. The experimental design and the material composition of each test group are the same as in Example 3.
Conventional Technology 1: Vinylon Staples (Technology of Patent Document 1)
Conventional technique 2: Palm staple fiber (Technology of Patent Document 2)
Invention 1: Staple material A + Staple material B 1 kg / m ³ compounded Invention 2: Staple material A + Staple material B 2 kg / m ³ compounded

The test was carried out using a construction machine that was actually used, and the vegetation base material that had been sufficiently agitated with a shaftless mixer was sprayed onto a plastic container with an internal size of 39.0 cm x 23.7 cm and a height of 7.0 cm. A specimen was created. The specimen was sheet-cured indoors, and using a rainfall experiment device, the rainfall was 100 mm / h and the raindrop diameter was 2.5 mm (generally after 1 week of curing) and when the substrate was dried (generally after 5 weeks of curing). Artificial rainfall (vibration motor rotation speed 500 rpm) was allowed to fall for 1 hour.

FIG. 8 is a graph showing a comparison of the amount of eroded soil during wet and dry conditions.
As a result of the test, when the substrate was wet (n = 3), no difference was observed between the prior art 1 and the staple fiber material B compounding amount of 1 kg / m ³ , but the staple fiber material B was found. A high significant difference (p <0.01) was observed between the compounding amount of 2 kg / m ³ and it was confirmed that the erosion resistance was 11.7 times higher. In addition, a high significant difference (p <0.01) was observed between the prior art 2 and the present invention, and the staple fiber B compounding amount of 1 kg / m ³ was 1.9 times, and the 2 kg / m ³ compounding amount was 23. It was confirmed that it exhibited twice as high erosion resistance.

On the other hand, when the substrate was dried (n = 3), the difference was small in all the test sections, and no difference was observed between the prior art 1 and the present invention, but the prior art 2 and the present invention were short. There is a relatively high probability of a difference between the fiber material B blending amount of 1 kg / m ³ (p = 0.24) and the staple fiber B blending amount of 2 kg / m ³ (p = 0.18). It was confirmed that the erosion prevention effect was 1.5 to 1.6 times higher.

From the above results, it was confirmed that in the present invention, by setting the blending amount of the staple fiber material B to 2 kg / m ³ , the effect of improving the erosion resistance of the growth substrate can be exhibited both when the substrate is wet and when the substrate is dried. rice field.

[Example 5] Verification of durability of growth base In order to verify the durability (effect of preventing separation) of the growth base of the present invention, an embankment slope having a length of 4 m and a gradient of 1: 1.0 was used. The following comparative tests were conducted on the rock slope (northwest facing pseudo-rock slope) and the earth and sand slope (southeast facing). The bedrock slope is a pseudo-rock slope in which concrete blocks of 30 cm × 30 cm are laid out so that the joint spacing is about 5 mm. The spray thickness of the growth base was 5 cm thick on the rock slope and 3 cm thick on the earth and sand slope.

From the results of Examples 1 to 3, the prior art 1 and the prior art 2 are almost the same, and the blending amount of the staple fiber material B in the present invention is 2 kg / m more than the blending of 1 kg / m ³ . Since it was confirmed that the combination of ³ was more suitable, the organic thick-layer base material spraying work (without the staples) and the conventional technique 2 were set as the control group. did.

Wire netting work + organic vegetation base material spraying work Present invention: Staple material A + Staple material B
Conventional technique 2: Palm staple fiber (Technology of Patent Document 2)

The material composition of the prior art 2 is the same as in the previous examples. In addition, the material composition per 1 m ³ of the present invention in this test is as follows.
Growth base material (organ soil) 2000L
Staple A (palm fiber) 80L
Staple B (polyester fiber) 2 kg
Clay mineral (bentonite) 10 kg
Erosion prevention material (Remi Control) 60kg
Slow-release fertilizer (high control) 4 kg

In each test plot, organic growth base material (trade name: Olga Soil) 2000 L / m ³ , inorganic erosion preventive material (trade name: Remi Control) 60 kg / m, and slow-release fertilizer (trade name: High Control) 4 kg. / M ³ ) is common. For the survey, survey plots were set at 3 sites / test plots after 46 days and 105 days, and the drying shrinkage crack interval, the measurement of the drying shrinkage crack length per unit area, and the separation of the growth base were observed.

FIG. 9 is a graph showing a comparison of drying shrinkage crack intervals (three-way ANOVA).
Regarding the drying shrinkage crack interval, slope conditions (rock slope, earth and sand slope), applicable method (vegetation base material spraying work using wire meshing work, present invention, prior art 2), and elapsed days (46 days later, 105) Three-way ANOVA was performed for the three factors (day later). As a result, a high significant difference (p <0.01, p <0.05, p <0.01, respectively) was observed for each factor of slope condition, applied construction method, and elapsed days, and the result of Tukey's multiple comparison test was found. Although the difference between the vegetation base material spraying work using the wire net and the prior art 2 is small (p = 0.46), the present invention and the vegetation base material spraying work using the wire net together, and the present invention A significant difference (p <0.05) from the prior art 2 was observed.

Although the drying shrinkage crack interval varies depending on the slope conditions and the number of days elapsed, it was confirmed that the present invention has an excellent crack suppressing effect as compared with other test plots. Further, when the crack suppressing effect of the present invention is compared according to the slope conditions, it is 54 to 64% on the bedrock slope and 87 to 93% on the earth and sand slope as compared with the vegetation base material spraying work using the wire netting work. Compared with the prior art 2, the effect of reducing the rock slope to 76 to 83% and the earth and sand slope to 67 to 72% was observed.

FIG. 10 is a graph showing a comparison of drying shrinkage crack lengths (three-way ANOVA).
Regarding the extension of dry shrinkage cracks, slope conditions (rock slope, earth and sand slope), applicable method (vegetation base material spraying work using wire meshing work, present invention, prior art 2), and elapsed days (46 days later, 105) Three-way ANOVA was performed for the three factors (day later). As a result, significant differences (p = 0.06, p <0.05, p = 0.20, respectively) were observed for each factor of slope conditions, applied construction method, and elapsed days, and the results of Tukey's multiple comparison test were found. Although the difference (p = 0.25) between the present invention and the prior art 2 was small, there was a high significant difference (p <0.05) between the present invention and the vegetation base material spraying work in which the wire netting work was used in combination. ) Is recognized, and the present invention has an excellent crack suppressing effect as compared with a general vegetation base material spraying work in which a wire netting work is also used, and there is a relatively high probability of difference as compared with the prior art 2. It was confirmed that there was.

Although the dry shrinkage crack prolongation varies depending on the slope conditions and the number of days elapsed, it was confirmed that the present invention has an excellent crack suppressing effect as compared with these control groups. Further, when the crack suppressing effect of the present invention is compared according to the slope conditions, it is 31 to 37% on the bedrock slope and 42 to 43% on the earth and sand slope as compared with the vegetation base material spraying work using the wire netting work. Compared with the prior art 2, the effect of reducing the rock slope to 45 to 71% and the earth and sand slope to 65 to 76% was observed.

The reason why the crack interval and the crack extension of the vegetation base material spraying work combined with the wire meshing work became the largest is that cracks occurred along the mesh of the wire mesh due to the drying shrinkage of the growth base. Such a phenomenon is likely to occur especially when the spray thickness of the growth base is thin. When the present invention is applied as a vegetation base material spraying work in which a wire meshing work is also used, the effect of suppressing the generation of cracks along the wire mesh can be expected.

FIG. 11 is a photograph comparing the peeling state of the growth base confirmed 105 days after the construction.
In addition, as a problem of the vegetation base material spraying work that omits the wire netting work, there is a problem that the sprayed growth base is separated by the wind depending on the site, or the growth base is lifted and separated by the emergence of the root weeds. .. At the time of the investigation 105 days after this test, the separation of the growth base was observed in the test plot of the prior art 2 on the earth and sand slope, whereas the test of the vegetation base material spraying work using the present invention and the wire netting work together. No separation was allowed in the ward. From this result, it was confirmed that the present invention has an excellent effect of suppressing the separation of the growth base as compared with the prior art 2, and a sufficient effect is exhibited even with a thin spray thickness of 3 cm.

[Example 6]
Taken together, the present invention can achieve the desired effects in the case of at least the following formulations. The amounts of erosion-preventing materials, fertilizers, and seeds other than those listed below are design items.
Growth base material 2000L
Staple material A 20-100L
Staple material B 1-5kg
Clay mineral 5-50kg

More preferably, the desired action and effect are obtained in the case of the following formulation.
Growth base material 2000L
Staple material A 40-80L
Staple material B 1-2 kg
Clay mineral 10-30kg

Claims (2)

The vegetation base material used in the greening method in which the vegetation base material is directly sprayed onto the slope without using the netting work as the greening foundation work.
It is a mixture containing at least a growth base material as a main material, a clay mineral, a first staple fiber material (A), and a second staple fiber material (B).
In the first short fiber material (A) and the second short fiber material (B), the first short fiber material (A) is relatively hard and the average fiber length is 4.5 cm ± 3. A vegetation base material having 0 cm and the second short fiber material (B) being soft and having an average fiber length of 2.0 cm ± 1.0 cm . It is a slope spraying greening method that uses a vegetation base material without using a netting work as a greening foundation work.
A step of preparing a vegetation base material by mixing at least a growth base material as a main material, a clay mineral, a first staple fiber material (A), and a second staple fiber material (B).
It has a step of directly spraying the vegetation base material on a slope.
In the first short fiber material (A) and the second short fiber material (B), the first short fiber material (A) is relatively hard and the average fiber length is 4.5 cm ± 3. A slope spray greening method characterized by 0 cm , the second staple fiber material (B) being soft, and an average fiber length of 2.0 cm ± 1.0 cm .

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