Water storage, infiltration, and water retention structures in the ground

Abstract

This invention provides an underground water storage, infiltration, and water retention structure that can suppress rainwater runoff and tree root uplift by allowing rainwater to permeate into the ground with a simple structure. [Solution] The water storage and infiltration structure 1 consists of storage structures 5, 6, and 7 embedded in a vertical hole 8 formed in the ground 11 near a tree 10, extending downward from the surface into the ground. The storage structures consist of a first storage structure 5 made of glass foam 2, a second storage structure 6 with bamboo chips 4 layered on top of the glass foam 2, or a third storage structure 7 with soil 3 layered on top of the glass foam 2, with bamboo chips 4 layered on top of the soil 3. Each storage structure is inserted into the vertical hole 8 in a state where it is previously contained in a bag 9 made of hemp or the like.

Description

Technical Field

[0001] The present invention relates to a water storage, infiltration, and water retention structure in the ground.

Background Art

[0002] Climate change caused by global warming and the like has brought about serious floods by causing large amounts of rain locally and suddenly. In urban areas, since the ground surface is covered with asphalt or concrete, rainwater does not penetrate into the ground and flows into sewers and rivers, causing flooding. Rainwater that does not penetrate into the ground flows on the ground surface and, even if it penetrates, remains in a shallow layer in the ground. As a result, the roots of street trees grow creeping near the ground surface. Then, it pushes up the pavement from below to raise the ground, or the roots creep out from the ground surface and are exposed from the ground.

[0003] In such a background, conventionally, technologies having a function of suppressing the root growth of street trees and a rainwater infiltration function have been proposed. For example, Patent Document 1 discloses a method for controlling the growth of street trees in which an electrode is installed near the root of a street tree and a pulsed electric field is applied to suppress the growth of the root (hereinafter, the technology described in Patent Document 1 is referred to as "Literature Known Invention 1").

[0004] On the other hand, for example, Patent Document 2 discloses a rainwater infiltration promotion facility in which a plurality of layers having different water permeability and water retention are laminated below a planting soil layer to infiltrate rainwater into the ground (hereinafter, the technology described in Patent Document 2 is referred to as "Literature Known Invention 2"). This technology suppresses the surface runoff of rainwater and infiltrates the rainwater into the ground over time while temporarily storing the rainwater in a storage layer, and has a configuration that also takes into account the maintenance of the planting environment.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

[0006] However, as mentioned above, while the invention in prior art 1 can suppress root uplift, it requires electrodes and pulsed electric field generators, making the equipment complex and resulting in high construction and maintenance costs. Furthermore, the invention in prior art 2 requires the formation of multiple layers with different water permeability and water retention properties underground, resulting in a wide construction area and a complex construction process. Therefore, it is difficult to easily install it on existing sidewalks and planting areas.

[0007] This invention was proposed in view of these circumstances, and aims to provide an underground water storage, infiltration, and water retention structure that can suppress rainwater runoff and tree root uplift by allowing rainwater to permeate into the ground with a simple structure. [Means for solving the problem]

[0008] To achieve the above objective, the underground water storage, infiltration, and water retention structure according to the present invention is characterized by having a hole formed near a tree that extends from the ground surface into the ground, and a storage structure embedded in the hole, wherein the storage structure has glass foam.

[0009] The underground water storage and infiltration structure according to the present invention is characterized in that the storage structure has bamboo chips laminated on top of the glass foam.

[0010] The underground water storage and infiltration structure according to the present invention is characterized in that the storage structure comprises soil layered on top of the glass foam and bamboo chips layered on top of the soil.

[0011] The underground water storage, infiltration, and water retention structure according to the present invention is characterized in that the storage structure is buried in the hole in a state in which it is previously housed in a bag. [Effects of the Invention]

[0012] The underground water storage, infiltration, and water retention structure according to this invention has a hole formed near a tree that extends from the ground surface into the ground, and a storage structure embedded in the hole, the storage structure having glass foam. Glass foam is relatively easy to obtain, so it is low cost, and the storage structure has a simple structure using glass foam. Furthermore, because glass foam is porous with a high void ratio, it can store a large amount of rainwater underground. Therefore, it can suppress rainwater runoff. Moreover, since the hole in which the glass foam is embedded is drilled downward from the ground surface into the ground, it can guide the tree roots to a deep position underground. Therefore, it can suppress tree root uplift.

[0013] The underground water storage and infiltration structure according to this invention has a storage structure in which bamboo chips are laminated on top of glass foam. The bamboo chips absorb rainwater and allow it to permeate downwards, thus guiding rainwater to the glass foam below. The glass foam has higher water absorption than the bamboo chips and, because it is buried underground, allows rainwater to permeate deep into the ground. Therefore, it can suppress rainwater runoff and tree root uplift.

[0014] The water storage, infiltration, and water retention structure in the ground according to this invention has a storage structure that consists of soil layered on top of glass foam and bamboo chips layered on top of the soil. The layering of soil improves water retention and nutrient retention, and the water storage, infiltration, and water retention structure functions as a planting base, thus maintaining a good growing environment for trees.

[0015] In the underground water storage, infiltration, and water retention structure according to this invention, the storage structure is buried in the hole in a state where it is pre-filled with a bag. Therefore, the storage structure can be easily buried underground. [Brief explanation of the drawing]

[0016] [Figure 1] Figure 1 is a schematic cross-sectional view of a water storage, infiltration, and water retention structure in the ground according to an embodiment of the present invention.

Mode for Carrying Out the Invention

[0017] Hereinafter, a water storage infiltration water retention structure in the ground according to an embodiment of the present invention (hereinafter, simply referred to as "water storage infiltration water retention structure") will be described based on the drawings. In FIG. 1, a schematic cross-section of the water storage infiltration water retention structure 1 is shown.

[0018] As shown in FIG. 1, the water storage infiltration water retention structure 1 is, for example, a structure in which a storage structure is buried in a vertical hole 8 formed downward from the ground surface through the ground 11 near a tree 10 which is a street tree. There are three types of storage structures. Specifically, it is composed of a first storage structure 5 made of a glass foam 2, a second storage structure 6 in which bamboo chips 4 are laminated on the glass foam 2, and a third storage structure 7 in which soil 3 is laminated on the glass foam 2 and bamboo chips 4 are laminated on this soil 3. Each of the storage structures 5, 6, 7 is accommodated in a bag 9 in advance. The glass foam 2 functions as a functional layer for storing and infiltrating rainwater, the soil 3 functions as a growth base for the tree 10, and the bamboo chips 4 have a function of guiding rainwater to the lower layer.

[0019] The glass foam 2 is, for example, cullet recovered from waste glass such as glass containers and glass products. The glass foam 2 has a porous structure with fine voids and is lightweight. Specifically, the characteristics of the glass foam 2 are as follows.

[0020] Dry specific gravity 0.67 - 0.78 g / cm 3 Water content ratio after penetration test (JIS A 1211) 34 - 44% Average CBR (JIS A 1211) 21 - 43% Permeability coefficient (JIS A 1218) 1.34×10 -5 ~9.52×10 -5 m / s Void ratio (JIS A 1104) 12 - 30% Water absorption rate (method of measuring the mass before and after immersing the sample in water for one day) 40 - 90%

[0021] The soil 3 is, for example, organic soil containing natural fertilizers such as fallen leaves. The bamboo chips 4 are, for example, bamboo cut from abandoned bamboo forests or the like, which are crushed and pulverized. The bag 9 in which each of the storage structures 5, 6, 7 is accommodated is arbitrary as long as it has at least water permeability. Therefore, for example, it may be a jute bag, a coconut fiber bag, a cotton bag, or the like. Also, the bag 9 preferably has air permeability and biodegradability.

[0022] The number and combination of each of the storage structures 5, 6, 7 are arbitrary. Therefore, for example, there are modes in which only the first storage structure 5 is buried, only the second storage structure 6 is buried, only the third storage structure 7 is buried, the first storage structure 5 and the second storage structure 6 are buried, the first storage structure 5 and the third storage structure 7 are buried, the second storage structure 6 and the third storage structure 7 are buried, and all of the first storage structure 5, the second storage structure 6, and the third storage structure 7 are buried.

[0023] The thicknesses of the glass foam 2, the soil 3, and the bamboo chips 4 in each of the storage structures 5, 6, 7 are arbitrary. For example, the glass foam 2 is 1 to 100 cm, the soil 3 is 1 to 100 cm, and the bamboo chips 4 are 1 to 50 cm.

[0024] The water storage infiltration and water retention structure 1 described above is constructed as follows. First, a screw drill or the like is rotated for excavation to form vertical holes 8 having a diameter of 1 to 100 cm and a depth of 3 to 300 cm at a plurality of locations in the ground 11. Each of the storage structures 5, 6, 7 is inserted into and buried in the vertical hole 8. According to the water storage infiltration and water retention structure 1 constructed in this way, the following effects are achieved.

[0025] Since glass foam 2 is a relatively easily obtainable material, the water storage, infiltration, and water retention structure 1 can be constructed at low cost. Due to its porous structure with a high void ratio, glass foam 2 can temporarily store large amounts of rainwater underground and has permeability that guides it to deeper parts of the ground. Therefore, it can suppress rainwater runoff to the ground surface. In addition, since air is retained in the voids of glass foam 2, a good ventilation environment can be ensured around the roots of the trees 10. Furthermore, since glass foam 2 has the physical and chemical properties necessary for practical use as a planting base aggregate, it functions as a growth base for trees 10. Moreover, by filling the vertical hole 8, glass foam 2 guides rainwater to deeper parts of the ground without accumulating near the ground surface, and because it has a void structure that allows the roots of trees 10 to extend into the interior, it can guide the roots of trees 10 to a deep position underground. As a result, it is possible to suppress the concentration of tree root growth in the shallow layers, thus suppressing root uplift, pavement surface uplift, and root exposure of trees 10.

[0026] Because soil 3 can contain sand and fertilizer, its water retention and nutrient retention properties are improved, and it can retain the nutrients necessary for the growth of trees 10. In addition, because soil 3 can work together with glass foam 2 to retain rainwater, it is easy to supply moisture to trees 10 even after rainfall. Therefore, the water storage, infiltration, and water retention structure 1 functions as a planting base and can maintain a good growing environment for trees 10.

[0027] Bamboo chips 4 are robust and resistant to degradation from ultraviolet rays, making them less prone to cracking and chipping. Furthermore, weeds do not easily grow on bamboo chips 4. In addition, bamboo chips 4 temporarily hold rainwater and allow it to permeate to the lower layers, thus suppressing rainwater runoff from the surface and promoting penetration into the glass foam 2. As a result, rainwater is more easily guided to deeper parts of the ground, and the roots of trees 10 can extend deeper into the ground, thus suppressing root uplift of trees 10.

[0028] Due to the advantages described above, the water storage and infiltration structure 1 can retain rainwater in the ground, making it easier to supply moisture to the trees 10 even during dry periods. As a result, the frequency of watering can be reduced, reducing the burden of maintenance and enabling water conservation. Furthermore, since each storage structure 5, 6, and 7 is inserted into the vertical hole 8 and buried while already contained in the bag 9, each storage structure 5, 6, and 7 can be easily buried in the ground.

[0029] In other embodiments of this invention, each storage structure is not housed in a bag but is directly buried in the ground.

[0030] Although embodiments of the present invention have been described in detail above, the present invention is not limited to the embodiments described above. Furthermore, various design modifications can be made to the present invention as long as they do not deviate from the matters described in the claims for utility model registration. [Explanation of Symbols]

[0031] 1. Water storage, infiltration, and water retention structure (Underground water storage, infiltration, and water retention structure) 2. Glass foam 3. Soil 4 bamboo chips 5. First Storage Structure 6. Second storage structure 7. Third Storage Structure 8 vertical holes (holes) 9 bags 10 Trees 11 Ground

Claims

1. A hole formed near a tree that leads from the surface into the ground, The storage structure is embedded in the aforementioned hole, The storage structure has a glass foam, A water storage, infiltration, and water retention structure in the ground characterized by the following features.

2. The aforementioned storage structure, The glass foam has bamboo chips laminated on top of it, A water storage, infiltration, and water retention structure in the ground as described in claim 1.

3. The aforementioned storage structure, The glass foam comprises soil layered on top of the glass foam, and bamboo chips layered on top of the soil. A water storage, infiltration, and water retention structure in the ground as described in claim 1.

4. The aforementioned storage structure, The bag is pre-filled and embedded in the aforementioned hole. A water storage, infiltration, and water retention structure in the ground as described in any one of claims 1 to 3.

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