JP2020031595A - Slope spraying greening method and vegetation base material - Google Patents

Abstract

To provide slope spraying greening methods, especially vegetation base material spraying method, for enabling the strength of a vegetation base material to enhance while enabling a netting work to be omitted, when spraying alone to a thickness of 3 to 10 cm, particularly when spraying to a thickness of 3 to 5 cm that is most frequently employed.SOLUTION: Provided is a vegetation base material used in a greening method in which a vegetation base material is directly sprayed onto a slope, not in combination with a netting work as a greening foundation work, the vegetation base material being a mixture at least comprising a growth base material that is a main material, a clay mineral, a first short fiber material A, and a second short fiber material B, for the first short fiber material A and the second short fiber material B, relatively, the first short fiber material A is hard and has a long average fiber length, and the second short fiber material B is soft and has a short average fiber length. The average fiber length of the first short fiber material A is 4.5 cm ± 3.0 cm, and the average fiber length of the second short fiber material B is 2.0 cm ± 1.0 cm.SELECTED DRAWING: None

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slope spraying greening method that makes it possible to omit the netting work by increasing the strength of a growing base to be formed in a slope (including a slope) greening method using a netting work as a 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 wire mesh tensioning work (also referred to as lath stretching work).

  In the design and construction of slope revegetation, unless the slope slope is gentle, the surface soil is prevented from moving or sliding down, the stable growth base is sprayed, and the plant that is expected to be introduced or invaded is In order to improve the growth environment, after constructing a netting work as a greening foundation, the vegetation is grown by spraying methods such as vegetation base material spraying and soil spraying (also called soil seed spraying). The foundation is created.

  In addition to the spraying method, there is a spray reinforcing method in which long fibers called long fibers or continuous long fibers are mixed with sandy soil or the like and sprayed on a slope. Depending on such a construction method, and strictly depending on the quality of the base material, spraying the vegetation base material thickly to, for example, about 10 cm or more increases the independence of the growth base, so that the netting work may be omitted in some cases. Needless to say.

  Here, the netting method is a method of setting a net on a ground, and is generally classified into a wire meshing method and a resin netting method. Wire mesh upholstery has rigidity and is effective for preventing surface soil movement and slipping, maintaining stable growth base for spraying, and preventing peeling due to frost heaving on slopes. It is widely used for greening steep slopes. On the other hand, the resin net upholstery has no rigidity and is difficult to deal with frost heaves and falling rocks, so that it is often applied to embankment slopes with a gentle slope.

  Here, the vegetation method is a method of introducing a plant, and is roughly classified into a sowing method, a planting method, and a vegetation inducing method from the viewpoint of the aspect of the plant. Vegetation works can be broadly classified according to the method of construction. One of them is a spraying greening method using spraying (also referred to as a machine construction method), which is classified into seed spraying, soil spraying, and vegetation substrate spraying. . As a spraying greening method, a vegetation base material spraying method capable of spraying a growth substrate of 3 cm or more at a time even on a steep slope has been widely adopted mainly on a cut slope.

  Among these spraying greening methods, when applying a soil spraying method or a vegetation base material spraying method to create a thick growth base, the combination of netting work as a greening basic method becomes the standard for the above-mentioned reasons, and it has rigidity. Wire mesh upholstery is commonly employed.

  However, in the case of vegetation substrate spraying, the cost ratio required for wire mesh stretching is about 20% for a spraying thickness of 10 cm, about 33% for a pressure of 5 cm, and 41% for a spraying thickness of 3 cm. In fact, the cost ratio of 3 to 5 cm, which is likely to be adopted frequently, has a high cost ratio of 30 to 40%. In order to increase economic efficiency, the strength of the growth base is increased and the wire mesh work is omitted. A spraying greening method that can be used is required.

  As a method for increasing the strength of the growth base, a method disclosed in Patent Document 1 for improving the connectivity of the growth base by mixing a short fiber material with a vegetation base material has been put to practical use. For example, the growth base is 0.2 to 6% by weight of a short fiber material (polyvinyl alcohol-based fiber of synthetic fiber) having a single fiber fineness of 0.7 to 120 denier and an aspect ratio of 120 to 1300, and a bark. It contains at least 50% by weight of compost, 2 to 45% by weight of peat moss, and 0.1 to 25% by weight of a binder. As a result, the creation of a growth base free from cracking, collapse, falling off, and outflow is realized.

The weight of the growth base material varies depending on the material used and its water content. The vegetation base material spraying method "Sloped forest forestation method" (registration number: QS-980148-VE, which is a registration technology of the New Technology Utilization System (NETIS) for public works, etc. of the Ministry of Land, Infrastructure, Transport and Tourism) When the expiration) trial calculation example, the total weight of the growth base is generally in the range of 124~154kg / ^{m 3.} When converted to weight (rounded to one decimal place) based on this, the mixing amount of the short fiber material of 0.2 to 6% by weight is at least 0.2 to 7.4 kg / m ³ , and at most 0.3 to 9. since the 2 kg / ^{m 3,} it can be considered as the desired effect can be obtained by a short fiber material 0.2~9.2kg / ^{m 3} formulation.

  As another method, Patent Literature 2 discloses a growth base material prepared by mixing a compounding material such as an organic or inorganic material, a fertilizer, and an erosion inhibitor applied to the spraying greening method, and having a fiber length of 5 to 20 cm. A growth base material characterized by containing a fiber material (coconut fiber in the example) having a property of 5 to 40% by volume is shown. This realizes a growth base that is durable against drying of the growth base after construction.

In the organic vegetation base spraying work, the vegetation base is generally compacted to half by spraying to form a growth base. Therefore, 2000 L of growth base material is blended per 1000 L (liter) of the finished product. I do. When the fiber material of the growth base material of Patent Document 2 is converted into volume based on this, the blending amount of coconut fiber is 5 to 40% by volume is 100 to 800 L / m ³ . Since the bulk density of the unraveled coconut fiber is approximately 0.1, when converted into a weight based on this, it can be considered that the desired effect can be obtained by blending the coconut fiber with 10 to 80 kg / m ^3. .

  Furthermore, the construction method of Non-Patent Document 1 is a vegetation base material spraying method “non-las construction method” (registration number: QS-020028, publication period has expired), which is a NETIS registration technique and omits wire mesh tensioning work. Yes, it was developed and put to practical use by applying the techniques of Patent Documents 1 and 2. The construction method of Non-Patent Document 1 has two types: a specification using synthetic resin short fiber material and a specification using natural short fiber material. In recent years, natural short fiber materials that are friendly to the natural environment are adopted at many sites. Have been.

  As still another method, Patent Literature 3 discloses a method of manufacturing a recycled staple fiber material using the remaining yarn of a thread-wound paper tube. Residual yarns, which are long fibers drawn from a plurality of thread-wound paper tubes, are bundled and wound around a bobbin, and the remaining yarn bundle wound around the bobbin is sequentially pulled out by a cutting device and cut into a predetermined length. By this manufacturing method, a recycled short fiber material having a fiber length of 10 to 50 mm and an aspect ratio of 500 to 7000 is obtained.

In Patent Literature 3, cracks of a greening base formed by spraying are prevented or cracks are not noticeable by blending 1 to 5 kg / m ³ of polyester short fibers with a growth base material. . However, the effect of increasing the strength of mortar concrete and the growth base has not been obtained.

JP-A-7-327484 JP-A-10-1130069 JP-A-2013-238028 JP-A-2004-225330

Yoshida and Furuta (2002) Vegetation base spraying without wire mesh tensioning, Journal of the Japanese Society for Greening Engineering 28 (1), 193-196.

The method of non-patent document 1 based on Patent Document 1 and Patent Document 2 (method: Non-las method) is 2 kg / m ³ when vinylon short fibers are used as standard specifications and 8 kg / m when coconut fibers are used. ^By mixing the ^three, the connection effect of the growth base is enhanced, and the wire mesh work is omitted, and this method has been used at many sites.

  However, when constructed under conditions that are located on windy coastal areas or windy terrain, the growth base will peel off, or the weeds that originally grew on the ground will germinate and the growth base will rise and separate. There was a case to do. In order to make the conventional technology that can omit these netting works into a more reliable method, the development of a method that enhances the strength of the growth base and exerts the germination and growth promotion effect of the plant equal to or higher than that of the conventional technology is developed. Is required.

  The present invention is often the most often adopted, especially when spraying 3 to 10 cm thick alone without using an auxiliary construction method such as a buried fence in a slope spraying greening method, particularly a vegetation base material spraying method. It is an object of the present invention to realize a growth base in which the strength of the growth base is increased even when sprayed to a thickness of about 3 to 5 cm to 3 to 7 cm, which can omit the netting work.

In order to achieve the above object, the present invention provides the following configurations.
The 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 the slope without using the netting method as a greening foundation,
A mixture containing at least a growth base material serving as a main material, a clay mineral, a first short fiber material, and a second short fiber material;
The first staple fiber material and the second staple fiber material are relatively hard and the average fiber length is long, and the second staple fiber material is soft and average. A vegetation base material having a short fiber length.
Another aspect of the present invention is a slope spraying greening method using a vegetation base without using a netting method as a greening foundation,
A step of preparing a vegetation base material by mixing at least a growth base material serving as a main material, a clay mineral, a first short fiber material, and a second short fiber material;
Spraying the vegetation base material directly on the slope,
The first staple fiber material and the second staple fiber material are relatively hard and the average fiber length is long, and the second staple fiber material is soft and average. The fiber length is short.
In the above aspect, the average fiber length of the first short fiber material is 4.5 cm ± 3.0 cm, and the average fiber length of the second short fiber material is 2.0 cm ± 1.0 cm. Is preferred.

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

  As a result, when constructed under conditions that are located in windy coastal areas or terrain that becomes windways, which is a problem of the conventional technology, the growth base may peel off or grow originally on the ground. The problem that the weeds germinate and the growth base rises and peels off is eliminated.

  By these effects, it is possible to reduce the risk of the need for reworking of the greening work and the necessity of rebuilding according to the present invention.

FIG. 1 shows an experiment design table of Example 1. FIG. 2 is a table showing the results of the survey (plant cover ratio, community height, coverage / group degree) of Example 1. FIG. 3 is a table showing a three-way analysis of variance of Example 1. FIG. 4 is a graph showing comparison of the plant height of Bahiagrass (BaH) (two-way analysis of variance). FIG. 5 is a graph showing a comparison of Bahiagrass (BaH) density (two-way analysis of variance). FIG. 6 is a graph showing a strength comparison (uniaxial compression strength) of a growing substrate when wet. FIG. 7 is a graph showing a strength comparison (bending strength) of a growing substrate at the time of drying. FIG. 8 is a graph showing a comparison of the amount of eroded soil when wet and when dry. FIG. 9 is a graph showing a comparison of drying shrinkage crack intervals (three-way analysis of variance). FIG. 10 is a graph showing a comparison of drying shrinkage crack extension (three-way analysis of variance). FIG. 11 is a photograph for comparing the state of peeling of the growth base confirmed 105 days after 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 method as a greening foundation. The vegetation base material is a mixture containing at least a growth base material serving as a main material, a clay mineral, a first short fiber material A, and a second short fiber material B. The first staple fiber material A and the second staple fiber material B are relatively hard, the first staple fiber material A is relatively long, and the second staple fiber material B is soft. It is characterized by a short fiber length.

  The short fiber material A, which has a longer average fiber length than the short fiber material B and is hard, is blended to give a shear resistance (connection effect). Furthermore, by blending the clay mineral and the soft short fiber material B having a shorter average fiber length than the short fiber material A and a soft short fiber material B, the volume increase of the clay mineral caused by water absorption and the effective pore compression effect of the growth base due to the swelling pressure, A synergistic effect is obtained with the frictional force enhancing effect by the short fiber material A and the short fiber material B being entangled with the growth base material interposed therebetween, and as a result, the strength, erosion resistance and durability of the growth base are obtained. And enhanced plant viability.

  As a growth base material, besides bark compost and peat moss, composts such as pruned foliage, locally generated sediment, sandy soil, raw chips, composted chips, fermented sludge compost, and the like can be used. Particularly effective is a method classified as an organic vegetation base spraying method using an organic growth base material such as peat moss as a main material.

  The clay mineral is a clay mainly composed of a silicate mineral, and may be bentonite, kaolinite, montmorillonite, sericite, talc, zeolite, or the like. The clay mineral used in the present invention only needs to exhibit an effective pore compression effect of the growth base due to an increase in volume caused by water absorption and a swelling pressure, and bentonite widely used in civil engineering work is preferable. By mixing the clay mineral with the growth base material, it absorbs water and fills the voids in the organic base to increase the bonding strength of the erosion preventing material, and further increases the friction resistance of the short fiber material and A, B to be mixed. It works.

  The short fiber material A is a hard fiber having a longer average fiber length than the short fiber material B and has an effect of increasing the shear strength by being dispersed in the sprayed growth base. The short fiber material A is a fiber for the purpose of enhancing the shear resistance of the growth base material and reinforcing it. Steel fiber, stainless steel fiber, glass fiber, carbon fiber, ceramic fiber, aramid, nylon, vinylon, polyethylene, polypropylene, polyester Coconut fiber, cellulose fiber and the like can be used.

  However, what is important here is that the short fiber material A is not for reinforcing structures such as mortar and concrete that solidify, but for reinforcing a growth base for greening where it is difficult to obtain a peripheral friction force due to fibers. Due to the specificity, it is necessary to mix as long fibers as possible and disperse them in the substrate. For this reason, the short fiber material A has a certain degree of hardness (lumbar) in the fiber, the fiber surface is not smooth, but has irregularities, or the fiber is not linear but is bent. It is desirable to use a fiber that exhibits as strong a peripheral frictional resistance as possible when dispersed. Therefore, natural fibers whose fibers are linear and whose surface is not smooth as compared with chemical fibers are desirable, and palm fibers whose fibers are bent are particularly preferable.

  In addition, since the short fiber material A is a relatively hard fiber, when the fiber length is long, the stirring efficiency is remarkably deteriorated due to, for example, co-rotation of various materials by stirring and mixing by the mixer, and the uniformity in the vegetation base material. It is difficult to disperse the particles. In order not to disturb the workability and to disperse uniformly in the vegetation base material, it is preferable that the average fiber length of the short fiber material A is in a range of 4.5 cm ± 3.0 cm.

  The short fiber material B is a soft fiber having an average fiber length shorter and shorter than the short fiber material A, and is uniformly dispersed in the sprayed growth base, so that the short fiber B is entangled with the short fiber A while the growth base is interposed therebetween. This has the effect of increasing the bonding strength and shear resistance of the base 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 the short fiber material A, the surface is smooth, and the fiber is soft. It is valid. The type of the chemical fiber is not particularly limited. For example, the recycled short fiber material of Patent Document 3 is a polyester having the highest 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 is set to a range of 2.0 cm ± 1.0 cm. It is suitable.

  The classification of each of the short fiber materials A and B as hard or soft depends on whether the short fiber material A and the short fiber material B are relatively soft or hard. If the lengths of the short fiber materials A and B are shorter than the above range, the intended effect is not remarkable, and if the length is long, the workability deteriorates.

  As an example of the physical properties of the short fiber material, the short fiber A is preferably a natural fiber having an aspect ratio of 100 to 500, an elongation of 10 to 30%, and a tensile strength of 50 to 800 cN. Coconut fibers having a tensile strength of 10 to 30% and a tensile strength of 100 to 700 cN are more preferred.

  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 has an aspect ratio of 1000 to 3,500, an elongation of 40 to 60%, and a tensile strength. Polyester fibers of 2-10 cN are more preferred.

  At the time of construction, in addition to these materials, erosion control materials (joining materials), fertilizers, seeds, etc. are mixed in the same manner as in the normal slope spraying greening method. Erosion prevention materials include synthetic resin materials represented by vinyl acetate resin and inorganic materials represented by cement.In order to improve the erosion resistance and durability of the growth base, inorganic materials with strong bonding strength are used. Materials are suitable, and for example, an 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 action and effect of the present invention, there is a medium-to-long-term strength enhancement effect of the growth base by the entanglement effect of the short fiber material A and the short fiber material B with the root system of the plant introduced by the greening. The present invention is characterized in that the strength of a growth base is increased from a state immediately after construction without a plant root system. According to the observation at the time of the test construction conducted so far, the effect of increasing the strength of this growth base has been shown. Thus, it has been confirmed that the plant is in a state where it cannot be easily pulled out. Although the soil binding force by the root system is of course well known, the present invention provides a medium-to-long-term growth strength, erosion resistance, It was suggested that it is possible to enhance the sex and to expect a higher effect.

[About construction]
In order to increase the strength of the growth base by synthesizing the effective gap compression effect and the frictional force enhancement effect of the growth base by blending the short fiber materials A and B having different average fiber lengths and hardness relatively to the growth base. Therefore, it is important that the various materials are sufficiently stirred and uniformly mixed during construction.

  In the spraying greening method, there are cases where various materials are directly charged into a spraying machine and mixed, but in order to maximize the effect of the present invention, each material is represented in advance by a shaftless mixer. It is desirable to mix the mixture into a mixer having a high stirring efficiency. Further, it is necessary to mix water in order to obtain the bonding strength of the erosion preventing material. At this time, the short fiber materials A and B can be dispersed in the vegetation base material by sufficiently stirring and mixing in advance with the water. It should be noted that there is no problem even if the water is mixed with the shaftless mixer after stirring or after being put into the spraying machine after the stirring, and when the vegetation base material has a long pumping distance, the water is combined before the spraying nozzle. You may mix.

The results of test executions that demonstrate the inventive step of the present invention with respect to the prior art are shown as examples.
[Example 1] Verification of plant viability by field test Before completing the present invention, a basic test for determining suitable amounts of various materials suitable for plant growth was performed in advance of the present example. As a result, a mixed amount of the various materials do not hinder the plant growth properties, clay mineral (bentonite) 5 to 50 kg / ^{m 3,} the short fibrous material A (palm fiber) the 20~100L / ^{m 3,} the short fibrous material B It has been concluded that it is desirable to mix (polyester fiber) 1 to 5 kg / m ³ .

  Therefore, a test was conducted in which the upper limit and the lower limit of the more suitable blending amount were adopted in consideration of workability and economy within the range of the blending amount. In this test, in order to reconfirm the plant viability due to the blending of the short fiber material B, a test section in which only the polyester short fiber material was not added was provided.

  In order to verify whether or not there is a problem in plant viability as compared with the prior art (the method described in Non-Patent Literature 1 based on Patent Literature 1 and Patent Literature 2), the conventional technology 1 (vinylon short fiber) was used. And two sections of prior art 2 (coconut staple fiber), and three factors I of clay mineral (bentonite), staple fiber material A (coconut fiber), and staple fiber material B (polyester fiber) were set in the method of the present invention. , II and III were compared.

The construction was carried out using a construction machine to be actually used, and a growth base was sprayed on a 1.8 m × 1.8 m test plot installed in an experimental field in the technical center of Toko Geotech Co., Ltd. in Tochigi Prefecture. The experimental plan is as follows. In each test plot, 2000 L / m ^{3 of} organic growth base material (trade name: Olgasoil), 60 kg / m ^{3 of} inorganic erosion preventive material (trade name: Remi Control), and seed (tall fescue) (TF), creeping red fescue (CRF), yamahagi, sharinbai, akamegawiwa, yellowfin, oyamazakura) are common.

FIG. 1 shows an experiment design table of Example 1.
Conventional technology 1: Vinylon staple fiber (technology of Patent Document 1)
Conventional technology 2: coconut staple fiber (technology of Patent Document 2)
The present invention: three-factor experiment Factor I: clay mineral (bentonite),
Mixing amount (α 1: 10 kg / m ³ , α 2: 30 kg / m ³ )
・ Factor II: Short fiber material A (coconut fiber, trade name: Remi fiber)
Mixing amount (β1: 40 L / m ³ , β2: 80 L / m ³ )
・ Factor III: Short fiber material B (polyester fiber, trade name: Kiri fiber)
Mixing amount (γ: 1 kg / m ³ , γ 2: 1 kg / m ³ , γ ³ : 2 kg / m ³ )

The material composition per 1 m ^{3 of the} prior art 1 is as follows.
Growth base material (Orga soil) 2000L
Short fiber material (vinylon fiber) 2kg
Erosion control material (Remi Control) 60kg
Slow release fertilizer (high control) 4kg
Seed 1 set

The material composition per 1 m ^{3 of the} prior art 2 is as follows.
Growth base material (Orga soil) 2000L
Short fiber material (coconut fiber) 80L
Erosion control material (Remi Control) 60kg
Slow release fertilizer (high control) 4kg
Seed 1 set

FIG. 2 is a table showing the results of the survey (plant cover ratio, community height, coverage / group degree) of Example 1.
The results of the test, of plant coverage after construction 11 months, clay mineral 30kg / ^{m 3} formulation Reserve and short fiber material A80L / ^{m 3} formulation ku becomes higher than the prior art 1 and the prior art 2, community high even clay mineral 30kg / m ³ formulation ku becomes higher than the prior art 2 and the prior art 2, the degree-Gundo the plants were often generally control group 1 and equal to or predominant species.

  From these results, it was confirmed that the vegetation base using the material constituting the present invention had at least the same effect as that of the prior art, but rather had a growth promoting effect.

FIG. 3 is a table showing a three-way analysis of variance of Example 1.
Next, a three-way analysis of variance was performed on the height, height, and density of the plant to verify the effect of the mixing amount of the clay mineral, the short fiber material A, and the short fiber material B. As a result, no significant difference was observed for any of the factors except for some plants, and some were positive and negative with respect to the amount of the mixture. In the range of, it was confirmed that there was no problem, considering that the viability of each plant was the same.

In addition, when the spraying work was performed in the test construction, the spray resistance of the clay mineral 30 kg / m ³ compounding section was larger than that of the 10 kg / m ³ compounding section, and the viscosity of the vegetation base material was clearly higher. . Therefore, considering the workability in the execution work, it can be said that a clay mineral of 10 kg / m ³ is suitable.

[Example 2] Verification of plant viability on slopes On eastward and westward embankment slopes (15 m in length, slope 1: 1.4) in Fukushima Prefecture, conventional technology 1 and book by rapid greening with exotic herbs A comparative test of the invention was performed. The material composition per 1 m ³ of the present invention in this test is as follows. Plants (seeds) used are TF, CRF, Bermudagrass (BG), Bahiagrass (BaH), and Bird's Foot Trefoil (BFT).
Growth base material (Orga soil) 2000L
Short fiber material A (coconut fiber) 40L
Short fiber material B (polyester fiber) 2kg
Clay mineral (bentonite) 10kg
Erosion control material (Remi Control) 60kg
Slow release fertilizer (high control) 4kg
Seed 1 set

Two months after construction, exotic herbaceous plant communities dominated by BaH at a coverage of 5 on both the eastward slope and the westward slope, with an apparent vegetation coverage of 100% and no difference between construction methods Was. The total density for introducing species Higashimuki slope face is 1,208 present / m ^2, Saiko slope face reaches 992 present / m ^2, believed to analyze species competition among type is no much sense to influence Therefore, two-way analysis of variance was performed by the slope direction (eastward, westward) and the applied method (Prior Art 1, present invention) to compare the plant height and density of the dominant species BaH.

FIG. 4 is a graph showing a comparison of BaH plant height (two-way analysis of variance).
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 similarly to the result of Example 1. Was.

FIG. 5 is a graph showing a comparison of BaH densities (two-way analysis of variance).
Regarding the density, a high probability (p = 0.06) was found between Conventional Technique 1 and the present invention, confirming that the present invention has an effect of promoting 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 performed.
Conventional technology 1: Vinylon staple fiber (technology of Patent Document 1)
Conventional technology 2: coconut staple fiber (technology of Patent Document 2)
Invention 1: Short fiber material A + short fiber material B 1 kg / m ³ compounded Invention 2: Short fiber material A + short fiber material B 2 kg / m ³ compounded

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

  The test was carried out using a construction machine to be actually used. The vegetation base material sufficiently stirred with a shaftless mixer was packed in a plastic mold of φ5 cm × 10 cm to confirm the effect of increasing the strength of the growth base in a wet state. A specimen for a uniaxial compression test was prepared. Further, a vegetation base material is sprayed on 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 a strength enhancement effect of a growth base in a dry state is provided. Created. The specimen was cured in a room, and in the bending test, the base was removed from the plastic container and cut to a width of 10 cm to obtain a specimen.

  The difference between wet and dry test methods is that the growth base may dry shrink and become deformed as the age increases, and in such a state, short fibers are mixed for a uniaxial compression test. This is due to the difficulty in shaping the specimen.

FIG. 6 is a graph showing a strength comparison (uniaxial compression strength) of a growing substrate when wet.
Tukey's multiple comparison test was performed on the results of the uniaxial compression test (n = 9). As a result, the growth base in the wet state (water content ratio: 160.6%) was found to be short in the conventional technology 1, the conventional technology 2, and the present invention. Although there was no difference between the blending amount of the fiber material B and 1 kg / m ³ , when the blending amount of the short fiber material B was 2 kg / m ³ , there was a high probability between the prior art 1 and the prior art 2. (P <0.01, p = 0.08).

In addition, a significant difference (p <0.05) was also observed between the short fiber material B compounding amount of 1 kg / m ³ and the compounding amount of 2 kg / m ^3, and the growth base was in a wet state, that is, after the construction. Even in the absence of the short fiber material B, it was confirmed that by adding 2 kg / m ^{3 of} the short fiber material B, the strength of the growth base could be improved by about 18% as compared with the case where only the short fiber material A was used.

FIG. 7 is a graph showing a strength comparison (bending strength) of a growing substrate at the time of drying.
Tukey's multiple comparison test was performed on the results of the bending test (n = 5). As a result, the growth base in the dry state (water content: 35.9%) was found between the prior art 1 and the prior art 2 and the present invention. It was confirmed that there was no significant difference between the blending amount of the short fiber material B of 1 kg / m ³ and the blending amount of 2 kg / m ^3, which was equivalent.

Next, comparing the prior art with the present invention, a significant difference is found between the prior art 1 and the short fiber material B compounding amount of 1 kg / m ³ and 2 kg / m ³ of the present invention (the former p <0. 01, the latter p <0.05), and the strength was enhanced by 43 to 50%. In addition, there is also a high probability that there is a significant difference between the prior art 2 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 <0.05 and the latter p = 0. 11) was observed, and the strength was increased by 30 to 37%.

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

Example 4 Verification of Effect of Enhancing Erosion Resistance of Growth Base The following comparative test was performed to verify the effect of enhancing the strength of the growth base of the present invention. The experimental plan and the material composition of each test section were the same as in Example 3.
Conventional technology 1: Vinylon staple fiber (technology of Patent Document 1)
Conventional technology 2: coconut staple fiber (technology of Patent Document 2)
Invention 1: Short fiber material A + short fiber material B 1 kg / m ³ compounded Invention 2: Short fiber material A + short fiber material B 2 kg / m ³ compounded

  The test was performed using a construction machine actually used, and the vegetation base material sufficiently stirred with a shaftless mixer was sprayed onto a plastic container having an inner size of 39.0 cm × 23.7 cm and a height of 7.0 cm. Specimens were prepared. The test specimens were cured in a room indoors, and the rainfall was 100 mm / h and the raindrop diameter was 2.5 mm when the base was wet (approximately one week after curing) and when the base was dry (approximately five weeks after curing) using a rainfall test apparatus. Artificial rainfall at a vibration motor rotation speed of 500 rpm was allowed to fall for one hour.

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

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. There is a relatively high difference between the fiber material B content of 1 kg / m ³ (p = 0.24) and the short fiber material B content of 2 kg / m ³ (p = 0.18). It was confirmed that the erosion prevention effect of 1.5 to 1.6 times was exhibited.

From the above results, it was confirmed that in the present invention, by setting the blending amount of the short 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. Was.

[Example 5] Verification of durability of growth base In order to verify the durability (separation prevention effect) of the growth base of the present invention, an embankment slope having a length of 4 m and a slope of 1: 1.0 was used. The following comparative tests were performed on the rock slope (pseudo-rock slope facing northwest) and the earth and sand slope (facing southeast). The rock slope is a pseudo rock slope in which a concrete block of 30 cm × 30 cm is filled up with a joint spacing of about 5 mm. The spray thickness of the growth base was 5 cm on the rock slope and 3 cm on the sand slope.

Incidentally, the results of Examples 1 to 3, it is prior art 1 and the prior art 2 is substantially the same, and the amount of short fiber material B of the present invention, than 1 kg / m ³ mixing 2 kg / m ^Since it was confirmed that ^three blends were more suitable, as a control group, an organic-based thick layer base material spraying work (with no short fiber material) combined with a wire mesh tensioning work and a conventional technique 2 were set. did.

Wire mesh tensioning + organic vegetation base material spraying The present invention: short fiber material A + short fiber material B
Conventional technology 2: coconut staple fiber (technology of Patent Document 2)

The material composition of Prior Art 2 is the same as in the previous examples. The material composition per 1 m ³ of the present invention in this test is as follows.
Growth base material (Orga soil) 2000L
Short fiber material A (coconut fiber) 80L
Short fiber material B (polyester fiber) 2kg
Clay mineral (bentonite) 10kg
Erosion control material (Remi Control) 60kg
Slow release fertilizer (high control) 4kg

In each test plot, 2000 L / m ^{3 of} organic growth base material (trade name: Orgasoil), 60 kg / m of inorganic erosion prevention material (trade name: Remi Control), and 4 kg of slow-release fertilizer (trade name: High Control) / M ³ ) are common. In the investigation, investigation plots were set at three places / test plots after 46 days and 105 days, and the measurement of the interval between dry shrinkage cracks, the extension of dry shrinkage cracks per unit area, and the state of detachment of the growth substrate were observed.

FIG. 9 is a graph showing a comparison of drying shrinkage crack intervals (three-way analysis of variance).
Regarding the drying shrinkage crack interval, the slope condition (rock slope, earth and sand slope), applied method (vegetation base material spraying using wire mesh upholstery, the present invention, prior art 2), and elapsed days (after 46 days, 105 days) After 3 days, a three-way analysis of variance was performed for the three factors. As a result, a high significant difference (p <0.01, p <0.05, p <0.01, respectively) was recognized in each of the factors of the slope condition, the applied method, and the elapsed days, and the results of Tukey's multiple comparison test Although the difference between the vegetation substrate spraying method using the wire mesh and the prior art 2 is small (p = 0.46), the difference between the present invention and the vegetation material spraying method using the wire mesh is also small. A significant difference (p <0.05) was found between the prior art 2 and the prior art 2.

  Although the drying shrinkage crack interval varies depending on the slope condition and the number of elapsed days, it has been confirmed that the present invention has an excellent crack suppressing effect as compared with other test plots. In addition, when the crack suppression effect of the present invention is compared for each slope condition, it is 54 to 64% on the rock slope and 87 to 93% on the earth and sand slope as compared with the vegetation base material spraying method combined with the wire mesh work. Compared with the prior art 2, the effect of reducing the rock slope to 76 to 83% and the soil and sand slope to 67 to 72% was recognized.

FIG. 10 is a graph showing a comparison of drying shrinkage crack extension (three-way analysis of variance).
Regarding the extension of the drying shrinkage crack, the slope conditions (rock slope, earth and sand slope), the applied method (vegetation base material spraying combined with wire mesh tensioning, the present invention, prior art 2), and the number of elapsed days (after 46 days, 105 After 3 days, a three-way analysis of variance was performed for the three factors. As a result, remarkable differences (p = 0.06, p <0.05, p = 0.20, respectively) were recognized in each of the factors of the slope condition, the applied construction method, and the elapsed days, and the results of Tukey's multiple comparison test Although the difference (p = 0.25) between the present invention and the prior art 2 was small, a high significant difference (p <0.05) between the present invention and the vegetation substrate spraying method using the wire mesh work was used. ) Is recognized, the present invention has an excellent crack suppressing effect as compared with a general vegetation substrate spraying method using a wire mesh upholstery, and the difference is relatively high compared with the prior art 2. It was confirmed that there was.

  Although the drying shrinkage crack elongation varies depending on the slope condition and the number of elapsed days, it was confirmed that the present invention has an excellent crack suppressing effect as compared with these control groups. In addition, when the crack suppression effect of the present invention is compared by slope conditions, it is 31 to 37% on rock slope and 42 to 43% on earth and sand slope as compared with vegetation base spraying combined with wire mesh tensioning. Compared with the prior art 2, an effect of reducing the rock slope to 45 to 71% and the soil and sand slope to 65 to 76% was recognized.

  The cause of the largest crack interval and crack extension in the vegetation base material spraying method using the wire mesh upholstery is that cracks are generated along the mesh of the wire mesh with the drying shrinkage of the growth base. Such a phenomenon tends to occur particularly when the spray thickness of the growth base is small. When the present invention is constructed as a vegetation base material spraying method using a wire mesh upholstery, an effect of suppressing the occurrence of cracks along the wire mesh can also be expected.

FIG. 11 is a photograph for comparing the state of peeling of the growth base confirmed 105 days after construction.
In addition, as a problem with the vegetation base material sprayer who omitted the wire mesh work, there is a problem that the growth base sprayed is separated by wind depending on the site, or the growth base is lifted and separated by sprouting of the weed root weed. . At the time of the investigation 105 days after this test, detachment of the growth base was observed in the test plot of the prior art 2 on the soil and sand slope, whereas the test of the vegetation base material sprayer using the present invention and wire mesh upholstery together was performed. No separation was observed in the ward. From these results, it was confirmed that the present invention has an excellent effect of suppressing the detachment of the growth base as compared with the prior art 2, and a sufficient effect is exhibited even with a sprayed thickness as thin as 3 cm.

[Example 6]
Summarizing the above, the present invention can achieve the intended effects at least in the following cases. The amounts of the erosion preventing material, fertilizer, and seeds other than those described below are design items.
Growth base material 2000L
Short fiber material A 20-100L
Short fiber material B 1-5kg
Clay mineral 5-50kg

More preferably, the following effects can achieve the desired effects.
Growth base material 2000L
Short fiber material A 40-80L
Short fiber material B 1-2kg
Clay mineral 10-30kg

Claims (4)

The vegetation base material used in a greening method in which a vegetation base material is directly sprayed onto a slope without using a netting work as a greening foundation work,
A mixture containing at least a growth base material serving as a main material, a clay mineral, a first short fiber material (A), and a second short 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 has a long average fiber length. 2. A vegetation base material, wherein the short fiber material (B) is soft and has a short average fiber length.   The average fiber length of the first short fiber material (A) is 4.5 cm ± 3.0 cm, and the average fiber length of the second short fiber material (B) is 2.0 cm ± 1.0 cm. The vegetation base material according to claim 3, characterized in that: It is a slope spraying greening method that uses vegetation base materials without using mesh netting as a greening foundation,
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 short fiber material (A), and a second short fiber material (B);
Spraying the vegetation base material directly on the 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 has a long average fiber length. 2. A slope spraying greening method, wherein the short fiber material (B) is soft and has a short average fiber length.   The average fiber length of the first short fiber material (A) is 4.5 cm ± 3.0 cm, and the average fiber length of the second short fiber material (B) is 2.0 cm ± 1.0 cm. The slope spraying greening method according to claim 3, characterized in that: