JPH0226932B2 - - Google Patents

Description

[Detailed description of the invention]

B. Field of industrial application of the invention The present invention relates to a construction method for greening infrastructure in civil engineering work, etc. Specifically, when the soil quality of the slope or flat ground to be greened is poor for growing plants, such as bedrock, soft rock with little soil destruction, sandy soil, or heavy clay soil, we will create a thick layer of greening base that allows plants to grow. The invention relates to a construction method for growing plants and greening within the foundation. Conventional technology In this greening foundation creation, the created foundation itself becomes effective soil for greening.
Therefore, the thickness of the greening base to be created will vary depending on the effective soil volume of the original ground to be greened.
It is necessary to create the land at least 5 cm or more. For this reason, in the past, a large amount of soil has been brought onto steep slopes and other surfaces, and in order to create a greening base layer, muddy greening base material has been sprayed and deposited using a pump. However, when a greening base material suitable for this vegetation is mixed with water to form a slurry and then pumped, the aggregate structure of the soil is mechanically destroyed, and the soil attached to slopes becomes a single grain structure, and moisture As the soil evaporates, it becomes densely packed and consolidates, which not only reduces the ability of plants to grow within the created greening foundation, but also causes cracks, causing the original soil to peel off and, as a result, being washed away, which is a major problem. It had the following. In order to solve this problem, the inventors
In October, he applied for a patent (Japanese Patent Application No. 185420/1983) and developed an invention called the ``Soil Seed Spraying Method''. In the previous application, a low flocculating ability flocculant is mixed in advance with muddy soil material, and this is pumped, and an anionic polymer with high flocculating ability is agglomerated immediately after the soil material is discharged from a nozzle. The method involves mixing the agent to instantly coagulate and hydrophobicize the muddy soil material before spraying it. However, in the case of the previous application, the flocculation reaction started after the nozzle was discharged, and the reaction state varied when it adhered to the slope. However, if you try to apply a thick coating, it will become slippery and run off, making it difficult to apply an even thick coating during spraying. In addition, as other conventional techniques, for example,
For example, there is a method of mixing a flocculant in a pipe in front of the discharge port as in Japanese Patent No. 48-11604, but in this method, a film can be formed on the surface of the method due to the thickening effect of the flocculant. Since air is not mixed in during stirring, water cannot be separated, hydrophobicized, and quickly plasticized while being sprayed. Therefore, it is not possible to stably bring in a large amount of soil material, and it is absolutely impossible to create a soil layer with a thickness of 5 cm or more. is calculated to be approximately 0.3 mm, and its purpose is completely different from that of creating greening infrastructure on bedrock, etc., and it can be said that this technology is nothing more than surface treatment of the original ground. Problems to be Solved by the Invention In order to solve the above-mentioned drawbacks of the previous application, it is possible to make mud-like materials almost completely agglomerated and hydrophobic without variation, making them plastic and making them stable on slopes etc. as soil with cohesion. They conducted repeated research to develop a method for constructing greening foundations that could be sprayed onto trees. B. Structure of the Invention The present invention adjusts a greening base material to a fluid slurry material, pressure-feeds the mud material to a discharge port using a pump, and then pumps the slurry material into a stirring cylinder attached to the outside of the discharge port. A hydrophobic agent and air are introduced separately into the slurry, and these three are mixed and stirred in the stirring cylinder to immediately separate and hydrophobize the water used for slurrying, forming aggregates and voids in the slurry. The gist of the present invention is a construction method for creating a greening base with a aggregate structure suitable for vegetation, which is characterized by speeding up hydrophobicity, making it plastic, and ejecting it toward the construction surface with a binding force. Means for Solving the Problem Generally, soil changes state from liquid to solid as its water content changes. In other words, when the water content is extremely high, it becomes a suspension and has the fluidity of a liquid, and as the water content decreases, the fluidity changes to a paste-like state, and as the water content further decreases, the viscosity deteriorates and it becomes plastic. . As the water content decreases even further, it finally begins to exhibit solid properties. This change in soil condition in response to changes in water content is called consistency, which represents its resistance to flow. This is generally translated as consistency (liquid), binding force (plasticity), firmness (solid), etc., but it is schematically shown as follows.

[Table] Focusing on these properties of soil, the present inventor has developed a method for instantly making muddy materials hydrophobic and plasticized to give them binding power when sprayed using a hydrophobic agent, based on the action of the hydrophobic agent. When we conducted a detailed study on how plasticity occurs, we found that simply adding a hydrophobic agent after dispensing would cause hydrophobicity to slow down and make it difficult to exceed the liquid limit, resulting in variations in the plastic state and the slope surface. However, if air is introduced here and the three components, the muddy material, hydrophobic agent, and air, are forcibly mixed and stirred inside the stirring cylinder, the air is immediately removed. They discovered that plasticization with hydrophobicity and cohesive force occurs through mediation. That is, the greatest feature of the method of the present invention is that the mud material, plasticizing agent, and air are forcibly mixed and stirred inside the stirring cylinder and ejected. This allowed a large amount of soil to be deposited at once, creating a stable greening base that would not be washed away. In addition, it was found that a moderate amount of voids of various sizes were formed in the soil, which was aggregated and made hydrophobic and plasticized by doing this, and this void-forming aggregate structure was This provides an excellent vegetation effect. In the present invention, the greening base material is one based on soil, to which fertilizers, seeds, etc. are appropriately blended, and if necessary, vegetable fibers, erosion inhibitors, etc. are blended therein. This greening base material is then mixed with an appropriate amount of water to create a mud-like material. Furthermore, if roots such as Japanese grass (field grass, Japanese grass) are mixed into this greening base material instead of seeds, the method of the present invention can also be used as a sowing method. In other words, in general, grass (Western grass) can be propagated by seeds, but Japanese grass has a hard seed coat, so the germination rate is low, so it is possible to propagate by root mulch, such as tension grass, sowing grass, etc. Among these methods, the method of the present invention can be used as a sowing method. This sowing method can create approximately 10 times the area of lawn compared to the tension method, but in the past, there was no suitable mechanical equipment, and agricultural equipment such as cultivators and rollers were used. Seedlings for sowing are made by stripping the grass into pine-shaped roots (called sotsudo) and cutting them into short pieces to make seedlings for sowing.However, once cut into short pieces, seedlings for sowing cannot be stored for a long period of time, so it is necessary to improve construction efficiency and quickly. It is necessary to plant the grass, and the method of the present invention can be applied as a very suitable means for this sowing. As mentioned above, the muddy material mixed with seeds or roots is forced into the discharge port by a pump, and this discharge port has a constricted tip, and the muddy material is spouted from this outlet. That's what I do. A stirring cylinder is attached to the tip or outside of this discharge port. FIG. 1 is a side sectional view showing one embodiment of this discharge port and stirring cylinder. As shown in this figure, the slurry material a that is force-fed through the hose 6 is ejected from a discharge port 1 with a constricted tip into a stirring cylinder 4 attached to the tip of the discharge port 1. This stirring cylinder 4 is provided with a hydrophobic agent inlet 2 and an air inlet 3 separately, and from the hydrophobic agent inlet 2 a hydrophobic agent liquid adjusted to have an appropriate blending amount is introduced. Air is sucked in from the air inlet 3 due to the depressurizing effect caused by the jetting of the muddy material a.
The amount of hydrophobic agent introduced and the amount of air sucked can be determined by opening/closing tips 7 and 8 provided on each introduction pipe.
Of course, it can be adjusted by In addition, a suitable baffle plate 5 is protruded in the stirring cylinder 4, and the mud material a, the hydrophobic agent, and air are forcibly stirred and mixed by the baffle plate 5, etc. Inside, it becomes plastic soil b, becomes hydrophobic and plastic, and ejects from this outlet. In the present invention, the hydrophobic agent is an agent that acts on the muddy material containing the greening base material, has the effect of separating water and agglomerating the greening base material. Those with a large hydrophobic effect are preferable, and flocculants with a large thickening effect are unsuitable, so they are called hydrophobic agents to distinguish them from these. As this hydrophobic agent, for example, polyacrylamide hydrolyzate is most preferably used. Note that the hydrophobic agent in the present invention is not limited to this polyacrylamide hydrolyzate, and as mentioned above, any type of agglomerate that has a small thickening effect and a large hydrophobic effect can be used. . Function Since the present invention has the above-described configuration, the muddy material immediately after being discharged is forcibly mixed and stirred with the hydrophobic agent and air in the stirring cylinder, and immediately undergoes the process of agglomeration → hydrophobic → plasticization. The soil becomes a soil that has strong shear resistance against shearing, and in addition, voids of various sizes are formed in this plasticized soil, and a structure of aggregates is formed. In this way, the aggregated, hydrophobic, and plasticized soil is ejected toward the construction surface such as a slope, and it is possible to reliably adhere and stabilize the construction surface to a specified thickness or higher without any variation. be. Example 1 A greening base material having the following composition was used. Compound composition of greening base material (including clay loam organic fertilizer) …31.25 Vegetable fiber …12.00 Chemical fertilizer (N8, P8, K8) …0.50Kg Erosion inhibitor (special asphalt emulsion) …1.12 Seed (Kentatsuki 31F, etc.) 0.02Kg To this greening base material, 25.00 g of fresh water was added as water and kneaded in a tank to prepare a mud material. The above mud material formulation has a thickness of 5 cm attached to the construction surface.
This is the blending amount per 1 m ² when This slurry material is pumped by a slurry pump with a lifting height of 140 m, and is connected to a nozzle discharge port 1 and a stirring cylinder 4 attached thereto using a hose with an inner diameter of 40 mm as shown in Fig. 1.
led to. In addition, the outlet diameter of this discharge port 1 is 20 mm.
The inner diameter of the hose 6, 40 mm, was reduced to half. On the other hand, a hydrophobic agent having the following composition was introduced into the stirring cylinder 4 through a hydrophobic agent inlet 2 provided in the stirring cylinder 4. Hydrophobic agent composition (amount per ^1m3 ) Polyacrylamide hydrolyzate (25 mol%)
…0.008Kg Water (fresh water) …3.75 In addition, air suction from the air inlet 3 was adjusted using the opening/closing knob 8. As a result, the slurry material a that is vigorously discharged from the discharge port 1 into the stirring cylinder 4 is forcibly mixed and stirred with the hydrophobic agent and air by the baffle plate 5, etc. in the stirring cylinder, and immediately undergoes an agglomeration reaction. It spewed out from the tip of the stirring cylinder 4 while becoming hydrophobic and plasticized. The following experimental slope was created as a construction surface for this gushing soil. Experimental slope (see Figure 2) 50cm on a plywood board c 180cm long, 90cm wide, 10mm thick
A mm-th lath wire mesh a was spread over the entire surface and fixed at an 8-minute slope (52 degrees). When the above-mentioned muddy material was sprayed on this slope while being plasticized, the water used to make the greening base material muddy was quickly drained away, and the soil became a cohesive material with binding power and was stably attached to the slope. It stuck. In addition, the condition of the aggregated soil ejected by the opening/closing knob 8 of the air inlet 3 was adjusted while observing the condition, and the aggregated soil was made to be in the most preferable condition and ejected while being turned into aggregates and plasticized. FIG. 2 is a schematic cross-sectional view of the greening foundation constructed on the slope in this example. As shown in this figure, the greening base e created in accordance with this example adhered stably to the slope, and a base of about 5 cm in thickness could be created without variation by one spraying. For comparison, a test (comparative example) was conducted under the same conditions as in the example, except that the air inlet 3 in Fig. 1 was closed and no air was sucked in. There were large variations in the ground, making it impossible to create a stable foundation on the slope. Figure 2 shows this situation in cross-section. In the comparative example shown in this figure, in which spraying was performed without introducing air, the greening base e almost sagged and it was impossible to create it to a thickness of 1 cm or more. It was possible. In order to clarify the difference between this example and a comparative example in which no air is mixed, the soil material that has been sprayed in one continuous shot was sprayed toward the same slope as above until it was about to sag, and its thickness was increased. Measured and compared. This test was carried out in 4 sections, and the thickness was measured one hour after spraying when the soil material became stable. In all sections, the thickness was measured at the upper left, lower left, center, upper right, and lower right. It was given 5 points. As a result, the results shown in the following table were obtained.

【table】

[Table] As shown in these tables, in the example, approximately 5 cm
However, in the comparative example, the upper part is quite thin, and the average thickness of the lower part is only 1.2 cm, which shows that there is large variation and the thickness is also small. In other words, there is a very clear significant difference depending on whether or not air is mixed in, and by forcibly mixing and stirring the muddy material, hydrophobic agent, and air inside the stirring cylinder, hydrophobicity and plasticization are very effective. It has been proven that this can be done. In addition, many voids were formed in the aggregated soil of this example, and it is considered that the void formation was effective in making the muddy material hydrophobic and plastic. Next, in order to compare the amount of voids, the following test was conducted on the above-mentioned example and a comparative example in which no air was mixed. In other words, from the soil layer formed on the slope,
From the Examples and Comparative Examples, four pieces of soil with a volume of 5 cm ³ in a stable state were collected two days after spraying, crushed, each placed in a 500 c.c. beaker, and fresh water was injected. The soil was thoroughly stirred to completely destroy the soil aggregates. The muddy water in the beaker was left still for one day, and the sedimentation volume of each was measured. As a result, the results shown in the following table were obtained.

[Table] From this table, it can be seen that the volume of the settled soil of the example was about 20% smaller than the volume of the settled soil of the comparative example, and that the soil of the example contained air corresponding to this volume difference. As described above, the soil layer obtained by the method of the present invention contains a lot of air, and from this fact, the aggregated soil ejected by the method of the present invention has many voids inside. This is proven. Example 2 As a greening base material, instead of the seeds (Kentatsuki 31F, etc.) in the formulation in Example 1, grass roots (Sotsudo) that were loosened into pieces for 0.1 m ^{for 2} minutes were mixed, and all other ingredients were the same as in Example 1. were mixed in the same composition as in Example 1, and kneaded in a tank to prepare a slurry material. The blending amount of this mud material is per 1 m ² when the spraying thickness is 5 cm. In other words
This means that a 0.1 m ² lawn root becomes a 1 m ² lawn, which is 10 times the area compared to the so-called stretched turf method. This mud material was guided to the stirring tube 4 in the same manner as in Example 1, and the spraying of soil was carried out in the same manner as in Example 1, including the composition of the hydrophobic agent and the introduction of air. However, this work was carried out on a flat surface rather than an inclined surface, and the spray was applied to a total thickness of 5 cm. As a result, it was confirmed that this construction method is most suitable for creating lawns. In other words, it is possible to perform four tasks at the same time: adding soil (filling soil), fertilizing, inverting (burying the turf seedlings in the soil), and compacting, which is extremely effective as a mechanically sown turf construction method. Excellent results were obtained. It has also been found that the construction method of the present invention makes it possible to create the most ideal foundation for the growth of turf seedlings (root shoots). In other words, unlike seeds, turf seedlings (root capsules) are constantly respiring because they are overgrown, so if soil that does not form aggregates is applied to the entire root capsule, it will become difficult to breathe and may die, or poor drainage may result in stagnant water. However, in the construction method of the present invention, the soil that is sprayed together with the root root aggregates, and as shown in Example 1, countless voids are formed in the soil. This ensures the respiration of the turf seedlings and ensures the growth of turf buds. C. Effects of the Invention As explained in detail above, the construction method of the present invention is to discharge the slurry of the greening base material and forcibly mix and stir the hydrophobic agent and air. Reliable hydrophobicization of the soil has been achieved, and its plasticity is quickly achieved, and the water separated from the erupted soil is drained and becomes soil with binding power, which stably adheres to the construction surface and contributes to greening. It is possible to extremely effectively build a foundation of sufficient thickness without solidification or washing away, and without any variation. Moreover, since the soil has a cohesive structure and contains many voids, the greening base created therein has the effect of increasing water retention and fertilizer retention, as well as being highly breathable, allowing plants to grow. This makes it very suitable for germination and growth.

[Brief explanation of drawings]

FIG. 1 is a side sectional view showing one embodiment of a discharge port and a stirring cylinder used in the present invention. Fig. 2 is a side cross-sectional view of a soil layer sprayed onto an experimental slope, and shows an example of the method of the present invention and a comparative example. 1... Discharge port, 2... Hydrophobic agent inlet, 3... Air inlet, 4... Stirring cylinder, 5... Baffle plate, 6...
Hose, 7, 8...Opening/closing pot, a...Mud material,
b...plastic soil, c...plywood, d...lath wire mesh, e, e'...greening base.

Claims (1)

[Claims] 1 Prepare the edging base material into a fluid mud-like material,
The slurry material is pumped to the discharge port, a hydrophobic agent and air are separately introduced into a stirring cylinder installed at the end of the discharge port, and these three are mixed in the stirring cylinder. A greening foundation construction method characterized by stirring and immediately forming aggregates and voids in the muddy material to speed up hydrophobicity and make it plastic while ejecting it toward the construction surface.