JPWO2012004874A1 - Soil improvement method and soil improvement structure - Google Patents

Abstract

A water-absorbing soil container made of water-absorbing soil that is made of water-absorbing, water-releasing and water-swelling water-absorbing materials packed in a water-permeable bag. The water-absorbing soil pad 1 is buried in the soil 100, and the water-retaining layer 2 formed by the water-absorbing soil pad 1 is formed in the soil 100, so that even if rain does not immediately fall on the land filled with the water-absorbing soil pad 1, the water retaining effect is exhibited. In addition to making it possible to recycle the water-absorbing soil pad 1 used as a countermeasure against flooding in the event of a water disaster, it can be reused as the water-retaining layer 2 to effectively utilize the limited water resources on the earth. To promote water retention.

Description

  The present invention relates to a soil improvement method and a structure for soil improvement, and more particularly to a method for improving the water retention capacity of a soil by providing a water retention layer in the soil.

Recently, global warming is increasing CO ₂ emissions on Earth advances have occurred various problems associated with the temperature rise. Currently, various measures are being developed and implemented in consideration of the adverse effects of global warming on the future of humanity and the environment. As one of the countermeasures, greening campaigns such as road greening, factory greening, school greening, and park greening are being carried out. In addition, greening campaigns are underway to suppress desertification that is ongoing around the world.

  One of the most prominent methods for preventing desertification is the Josa method called Kusakakata. Kusakakata is a method of healing that uses wheat straw, and demonstrates great power to stop the movement of sand. Moreover, the technique which prevents desertification by forming a water retention layer in soil is also proposed (for example, refer patent documents 1 and 2).

  In Patent Document 1, a moisture layer in the soil is controlled by providing a hydrophobic layer made of hydrophobic particles (for example, water-repellent sand) in the soil at a predetermined depth from the ground surface, and soil at a predetermined depth from the ground surface. In particular, it is disclosed that a water retention layer containing a water retention agent (for example, a polymer compound having water retention property) is provided above the hydrophobic layer.

  Patent Document 2 discloses that a water retaining film having easy water absorption and difficult water release is spread in a desert area. Further, it is also disclosed that a water retention container comprising a top cover having a plurality of fine water supply openings, and a side wall and a bottom plate having a plurality of fine water discharge openings, in which a water retention material is enclosed, is embedded in the vicinity of the ground surface in a desert area. Has been. Furthermore, providing a high water absorption layer on the desert surface is also disclosed.

JP-A-6-113673 JP-A-10-313684

  However, urban greening on roads, factories, schools, parks, etc. always requires water supply to the soil. Water is supplied naturally when it rains, but artificial watering is often necessary due to the land with low rainfall and the season with low rainfall. For this reason, there is a problem that it takes much time and cost for watering.

  Therefore, it is conceivable to reduce the number of water sprays by forming a water retention layer described in Patent Document 1 or 2 in urban soil, thereby increasing the water retention capacity of the soil. However, even if the number of water sprays can be reduced, water for water spraying (water to be stored in the water retention layer) must be secured. In cities that require a large amount of water for domestic use or industrial use, the problem of water shortage is faced, and how to secure water other than the natural phenomenon of rainfall is an issue.

  This problem is particularly serious in the desert. In the first place, a desert is a land where there is not much rain and the amount of evaporation is greater than the amount of rainfall. Therefore, even if a water retaining layer is simply provided in the desert soil as in Patent Documents 1 and 2, it does not help anything until it rains on the land. After all, it is necessary to artificially prepare the water to be stored in the water retention layer after the water retention layer is formed in the desert. However, it is difficult to secure the water. From now to the future, there is concern about the global water shortage accompanying population explosions, and how to secure the water stored in the reservoir is an important issue.

  The present invention has been made to solve such problems, and an object of the present invention is to make it possible to promote the water retention of land by effectively utilizing the limited water resources on the earth.

  In order to solve the above-described problems, in the present invention, a water-absorbing soil is formed by packing a water retaining material having easy water absorption, difficult water release and water swellability in a water-permeable bag, and the occurrence of a water disaster. A water-absorbing soil pad that has been absorbed and absorbed in the water-retaining material is embedded in the soil, so that a water-retaining layer is formed in the soil.

  According to the present invention configured as described above, the water-absorbing soil pad used at the time of the occurrence of a water disaster such as a flood is buried in the soil, so that rain immediately falls on the land filled with the water-absorbing soil pad. Even without it, the water retention effect can be exerted on the land. Water that has been absorbed by the water retaining material gradually evaporates, but if it rains, the water retaining material absorbs water again, and the water retaining effect can be maintained.

  Further, according to the present invention, the water absorbed by the water retention material is surplus water generated by a water disaster such as flooding, and is not artificially prepared water. That is, according to the present invention, it is possible to reuse the water-absorbing soil pad that was used as a countermeasure against flooding in the event of a water disaster as a water-retaining layer, and to effectively utilize the limited water resources on the earth to retain the water in the land. Can be promoted.

It is a figure for demonstrating an example of the soil improvement method by this embodiment. It is a top view which shows the structural example of the water-absorbing earth clay by this embodiment. It is a figure for demonstrating the other example of the soil improvement method by this embodiment. It is a figure for demonstrating the other example of the soil improvement method by this embodiment. It is a figure which shows the example of the embedding method of the water-absorbing earth clay by this embodiment. It is a top view which shows the other structural example of the water-absorbing earth soil by this embodiment.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram for explaining a soil improvement method according to the present embodiment. As shown in FIG. 1, in the present embodiment, a plurality of water-absorbing soil bags 1 are arranged and buried in soil 100. For example, a plurality of water-absorbing soil pads 1 are embedded in the soil 100 at a predetermined depth from the ground surface. Thereby, the water retention layer 2 by the water-absorbing soil pad 1 is formed in the soil 100.

  The water-absorbing soil pad 1 embedded in the soil 100 is formed by packing a water-holding material having easy water absorption, difficult water release and water swellability in a water-resistant bag, and is actually used when a water disaster occurs. Thus, the water-absorbing soil has been absorbed by the water-retaining material. Hereinafter, the structure of the water absorbing soil bag 1 will be described in detail.

  FIG. 2 is a plan view showing a configuration example of the water-absorbing soil cave 1 according to the present embodiment. As shown in FIG. 2, the water-absorbing soil container 1 of this embodiment includes an outer bag 11, an inner bag 12, and a powdery or granular water-retaining material 13 (water-absorbing material) having easy water absorption, difficult water release and water swellability. And the like). The water retaining material 13 is stored in the water-soluble pack 14, and the water-soluble pack 14 is stored in the inner bag 12. The outer bag 11 and the inner bag 12 constitute a sandbag 10.

  The outer bag 11 has water permeability, and is constituted by, for example, a hemp bag woven roughly with tough fibers. The inner bag 12 also has water permeability, and is constituted by a thin cotton bag having high water permeability, for example. The edges of the outer bag 11 and the inner bag 12 are sewn with, for example, a thread. Use a strong thread like hemp thread. The size and shape of the outer bag 11 and the inner bag 12 are not particularly limited in this embodiment.

  The water-soluble pack 14 has a size smaller than that of the inner bag 12. For example, a polyvinyl alcohol (PVA) film is used as the material. The material of the water-soluble pack 14 is not limited to the PVA film, and other appropriate water-soluble materials such as water-soluble paper and wafer may be used. However, since the PVA film has very excellent characteristics from the viewpoint of environmental protection such as the presence of microorganisms that decompose PVA dissolved in water, it is preferable as a material to be embedded in the soil 100.

  Further, the PVA film has a feature that it can be heat-sealed with various heat sealing machines. Therefore, the water-soluble pack 14 can be easily packaged by storing a predetermined amount of the water retaining material 13 in the bag-like PVA film and then heat-sealing the bag entrance. Although the water-soluble pack 14 for storing the water-retaining material 13 is not essential, it is easier to handle the water-retaining material 13 when the water-soluble pack 14 is used. Since the water-soluble pack 14 dissolves as soon as it comes into contact with water and does not prevent the water-retaining material 13 stored therein from swelling, the size of the water-soluble pack 14 is set to the minimum necessary size. Can do. Therefore, handling at the time of the bagging operation to the clay bag 10 is very simple, and the working efficiency is good.

  The water retaining material 13 contained in the water-soluble pack 14 includes polyacrylate, saponified polyacrylonitrile, acrylate / vinyl alcohol copolymer, starch / acrylic acid graft copolymer, starch / acrylonitrile graft. Any superabsorbent polymer such as saponified copolymer, cellulose / acrylic acid graft copolymer, polyacrylamide and its partial hydrolyzate, polyvinyl alcohol, polyethylene oxide, and the like can be used. However, this is only an example, and any material having easy water absorption, difficult water release and water swellability can be applied.

  When the water-absorbing soil container 1 configured as described above is used as a countermeasure against flooding during a natural disaster such as a flood, the water retaining material 13 is swollen and gelled by the absorbed water. As a result, the sandbag 10 swells and actually functions as a sandbag. Here, the outer bag 11 is made of hemp having a coarse weave so that water can pass through quickly, and the inner bag 12 is made of thin cotton cloth so that the water can pass through quickly. That is, since both the outer bag 11 and the inner bag 12 are excellent in water permeability, if the absorbent soil pad 1 is used as a countermeasure against water discharge, water quickly enters the inner bag 12. The water-soluble pack 14 in the inner bag 12 dissolves as soon as it touches water, and the water retaining material 13 in the water-soluble pack 14 immediately touches water. Thereby, the water-retaining material 13 is swollen and gelled by water absorption, so that the swollen water-absorbing soil bag 1 can be formed.

  The swollen water-absorbing soil soil 1 can be used as the water-retaining layer 2 by being buried in the soil 100 as shown in FIG. In this case, since the water retaining material 13 has already absorbed water when the absorbent soil pad 1 is buried, the water retaining effect can be exerted on the land even if it does not rain immediately on the land filled with the absorbent soil pad 1.

  The water that has been absorbed by the water retaining material 13 gradually evaporates over time, but if it rains, the water retaining material 13 absorbs water again, and the water retaining effect can be maintained. If the water-absorbing soil pad 1 is buried at a depth of about 70 cm or more from the ground surface, ultraviolet rays and oxygen from the ground surface will not reach, and deterioration of the water retaining material 13 can be suppressed. Thereby, the water-absorbing soil pad 1 can exhibit the function as the water retention layer 2 over a long period of time.

  Further, the water absorbed by the water retaining material 13 is surplus water generated by a water disaster such as a flood, and is not artificially prepared water. In other words, in this embodiment, the water-absorbing soil pad 1 used as a countermeasure against flooding in the event of a water disaster can be buried in the soil 100 and reused as the water retention layer 2, and the limited water resources on the earth can be effectively utilized. Thus, water retention of the soil 100 can be promoted.

  In particular, in the desert, when a certain amount of rain falls, the soil has no water holding capacity, so the water flows through the surface faster than it soaks into the soil. As a result, floods may occur in the lowlands even if there is not much rainfall. Also, there are rivers in the desert even if water does not usually flow. If it rains occasionally, water flows into the river, but if the amount of water accumulated in the river exceeds a certain level, it will flow out as flash floods and may cause flood damage even in areas where it has not rained. According to this embodiment, when such a flood occurs, it is possible to take measures against flooding with the water-absorbing soil pad 1, and thereafter, the water-absorbing soil wall 1 having absorbed water can be used as the water retention layer 2.

  In addition, in the said embodiment, although the sandbag 10 was comprised by the outer bag 11 and the inner bag 12, this invention is not limited to this. For example, the sandbag 10 may be constituted by only the hemp outer bag 11. However, in this case, if the mesh is roughened to ensure the water permeability of the outer bag 11, the water retaining material 13 that has swollen due to water absorption may leak out. On the other hand, if the mesh is made fine in order to prevent leakage of the water retaining material 13, the water permeability is impaired. On the other hand, when the outer bag 11 and the inner bag 12 have a double structure, and the inner bag 12 is made of cotton, the mesh of the inner bag 12 is fine, so that the water retaining material 13 absorbs water and swells. Even if it does not leak.

  Moreover, although hemp and cotton were shown as a raw material of the outer bag 11 and the inner bag 12 in the said embodiment, this is only an example and this invention is not limited to these raw materials. For example, synthetic fibers such as polyester and acrylic fibers, or semi-synthetic fibers such as rayon are applicable, but natural fibers are preferably used in consideration of the natural environment when embedded in the soil 100. For example, the material of the outer bag 11 may be coconut fiber. The material of the inner bag 12 may also be hemp or cocoon fiber. Further, the outer bag 11 and the inner bag 12 are not limited to fibers, but may be a film-like sheet provided with fine holes.

  In the above embodiment, an example has been described in which a plurality of water-absorbing soil soil pads 1 are embedded in the soil 100 having a predetermined depth from the ground surface, but the method of filling is not limited to this example. For example, a plurality of water-absorbing soil soil pads 1 may be buried in an arbitrary position without being arranged. Moreover, you may embed one water-absorbing soil container 1 instead of a plurality.

  Further, as shown in FIG. 3, the water-absorbing soil soil 1 having been absorbed is buried in the soil 100 at the first depth from the ground surface, and the water-absorbing soil soil 1 having been absorbed in the soil 100 at the second depth from the ground surface. By embedding in the soil, two-stage water-retaining layers 2A and 2B may be formed in the soil 100. Of course, three or more stages of the water retention layer 2 may be formed in the soil 100. Thus, by providing the water retention layer 2 in two or more layers, the water retention capacity of the soil 100 can be further increased. In the example of FIG. 3, a space is provided between the upper water retention layer 2A and the lower water retention layer 2B.

  Moreover, although the said embodiment demonstrated the example which embeds the water-absorbing soil soil 1 directly absorbed in the soil 100, this invention is not limited to this. For example, as shown in FIG. 4A, the soil 150 is put into a container 20 having a rectangular parallelepiped shape and the upper surface being opened, and the water-absorbed soil pad 1 that has already absorbed water is buried in the soil 150. And as shown in FIG.4 (b), you may make it form the water retention layer 2 by putting together the container 20, the soil 150 accommodated in it, and the pad 1 of a water absorption soil in the soil 100 collectively. Moreover, as shown in FIG.4 (c), you may provide the water retention layer 2B by the water-absorbing soil pad 1 below the water retention layer 2A by the container 20 (it may be an upper side). Since the container 20 is also embedded in the soil 100, it is preferable that the container 20 be made of a degradable material that is decomposed by the action of water, microorganisms, or the like (for example, a degradable plastic or a crushed waste shell). In addition, the shape of the container 20 is not limited to a rectangular parallelepiped.

  In the case of the configuration shown in FIG. 4, the water-absorbing soil pad 1 is primarily used as a measure against flooding in the event of a water disaster, then buried in the soil 150 in the container 20 and secondarily used as a water retention layer for the planter. It can be buried and used for the tertiary use as the water retention layer 2 of the soil 100. The planter for secondary use can be used for plant cultivation at home, planted for planting, used for exhibitions, and various other purposes.

  In addition, when the container 20 is buried in the soil 100, planting seeds in the soil 150 can promote greening efficiently. In particular, when the container 20 is embedded in the desert soil 100, even if the sand moves by the wind blowing on the ground, the seeds charged in the soil 150 are not blown away by the wind. When plant seeds are put into the container 20, as shown in FIG. 4 (c), two-stage water-retaining layers 2A and 2B are formed in the soil 100, and the water-absorbing soil pad 1 that forms the lower water-retaining layer 2B is about 70 cm from the ground surface. The container 20 that forms the upper water-retaining layer 2A may be buried in a relatively shallow position of about 70 cm or less from the ground surface. If it does in this way, the plant which needs to plant a seed in the comparatively shallow position of soil 100 will be nurtured, suppressing degradation of water retention material 13 by lower water retention layer 2B, and maintaining a water retention effect over a long period of time. be able to.

  Moreover, in the said embodiment, when planting plants, such as a flower and a vegetable which roots shallower than the water retention layer 2 (or water retention layer 2A, 2B, and this paragraph similarly below) and roots deeper than the water retention layer 2 You may make it change the filling method of the water absorbing soil container 1 (or container 20, the same in this paragraph below) with the case of planting a plant such as a stretched tree. For example, when planting a shallow rooting plant, as shown in FIG. 5 (a), the absorbent soil pad 1 may be almost spread and a plant may be planted thereon. On the other hand, when planting a deeply rooted plant, as shown in FIG. 5 (b), a space of a predetermined size (area in which only the soil 100 is present and the water-absorbing soil soil 1 does not exist) 200 is formed between the water-absorbing soil soil 1s. It is good to plant a plant in the part of the space 200. In this way, it is possible to prevent the water-absorbing soil pad 1 from becoming an obstacle when the plant is rooted. 5 shows a state in which the water-absorbing soil pad 1 buried in the soil 100 is viewed from the upper surface of the soil 100.

  Moreover, although the said embodiment demonstrated the example which accommodates the water retention material 13 (what was put in the water-soluble pack 14) in the sandbag 10 and comprises the water-absorbing sandbag 1, this invention is not limited to this. For example, as shown in FIG. 6, in addition to the water retaining material 13, a water-absorbing soil bag 1 is configured by filling a soil bag 10 with a specific gravity adjusting material 15 that has poor water solubility and decomposability and has a higher specific gravity than water. It may be. In the example of FIG. 6, the water retaining material 13 is stored in the water-soluble pack 14, and the specific gravity adjusting material 15 is stored inside the inner bag 12 and outside the water-soluble pack 14.

  The specific gravity adjusting material 15 is used to make the water-absorbing soil soil 1 absorbed by the water-retaining material 13 heavier when the water-absorbing soil soil 1 is used in a water disaster, so that the water-absorbing soil soil 1 that has already absorbed water is less likely to flow into the water. Has function. In order to exhibit this function, the specific gravity adjusting material 15 is made of a material that has poor water solubility and a higher specific gravity than water. Moreover, since the water-absorbing soil soil pad 1 is buried in the soil 100 after taking measures against water discharge, the specific gravity adjusting material 15 preferably has degradability.

  For example, as the specific gravity adjusting material 15, it is possible to use discarded shells such as oysters and scallops. In the case of using the waste shell, it contains calcium carbonate as a main component, and therefore has a function as a nutrient source for plants when water-absorbing soil 1 is buried in the soil 100 and planted in addition to the specific gravity adjustment function. The discarded shells may be crushed and stored in the inner bag 12. Further, the crushed waste shell may be stored in the water-soluble pack 14 together with the water retention material 13 or may be stored in a water-soluble pack different from the water-soluble pack 14. .

  In addition, each of the above-described embodiments is merely an example of implementation in carrying out the present invention, and the technical scope of the present invention should not be construed in a limited manner. In other words, the present invention can be implemented in various forms without departing from the spirit or main features thereof.

  INDUSTRIAL APPLICABILITY The present invention can be used to form a water retaining layer by filling water-absorbed soil in the soil when performing greening such as urban greening or desert greening.

Claims (12)

A water-absorbing soil container made of water-absorbing soil that is formed by packing a water-retaining material with easy water absorption, difficult water release and water-swelling properties in a water-permeable bag, and used when water disaster occurs, A soil improvement method, wherein a water-retaining layer is formed in soil by embedding a completed water-absorbing sandbag in the soil. The soil improvement method according to claim 1, wherein the water-absorbed soil pad is buried in soil having a predetermined depth from the ground surface. By embedding the water-absorbed soil soil in the soil at the first depth from the ground surface, and embedding the water-absorbed soil soil in the soil at the second depth from the ground surface, a two-stage water retention layer The soil improvement method according to claim 1, wherein the soil is formed in soil. 2. The soil improvement method according to claim 1, wherein a plurality of the water-absorbing soil pads are embedded in a soil having a predetermined depth from the ground surface. When embedding a plurality of water-absorbing soil pads in the soil at a predetermined depth from the ground surface, it is assumed that a plant that has roots deeper than the depth from the ground surface where the water-absorbed soil soil is buried is planted. The soil-improving method according to claim 1, wherein the water-absorbing soil sandals are buried with a space of a predetermined size between the water-absorbing soil sands. Embed the water-absorbing soil pad in the soil housed in a container made of degradable material, and put the container, the soil housed in the container and the water-absorbed soil soil into the soil together in the soil. The soil improvement method according to claim 1, wherein the soil improvement method is embedded. The container and the soil contained in the container and the water-absorbed soil pad are buried together in the soil at a first depth from the ground surface, and the water-absorbed soil soil is second depth from the ground surface. The soil improvement method according to claim 6, wherein a two-stage water retention layer is formed in the soil by being embedded in the soil. 8. The water absorbing soil bag is formed by filling the bag with a specific gravity adjusting material that has poor water solubility and decomposability and has a higher specific gravity than water, in addition to the water retaining material. The soil improvement method according to claim 1. A bag having water permeability;
A water-retaining material housed inside the bag, having easy water absorption, difficult water release and water swelling,
A soil improvement structure comprising a specific gravity adjusting material housed inside the bag and having poor water solubility and decomposability and a specific gravity higher than water. The soil improvement structure according to claim 9, wherein the specific gravity adjusting material is a waste shell. A container made of a degradable material;
Soil stored in the container;
A water-absorbing soil container made of water-absorbing soil packed in a water-permeable bag with water-absorbing material, water-absorbing property, water-releasing property, and water-swelling property. It has a completed paddle
A structure for soil improvement, characterized in that the water-absorbing soil pad after water absorption is embedded in the soil. 12. The soil according to claim 11, wherein the water-absorbing soil pad is formed by filling the bag with a specific gravity adjusting material that has poor water solubility and decomposability and has a higher specific gravity than water in addition to the water retention material. Improvement structure.

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