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, infiltration, and water retention structure 1 consists of three layers: a glass foam layer 2 buried in the ground, a soil layer 3 stacked on top of the glass foam layer 2, and a bamboo chip layer 4 stacked on top of the soil layer 3.

Description

Technical Field

[0001] This 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 or rivers, causing flooding. Rainwater that does not penetrate into the ground flows on the ground surface and, even if it penetrates, stays in a shallow layer in the ground. As a result, the roots of street trees grow along the vicinity of the ground surface. Then, it pushes up the pavement from below to raise the ground surface, or the roots grow out from the ground surface and are exposed from the ground. <00\00013>

[0003] In such a background, conventionally, technologies having a function of suppressing the root growth of street trees and rainwater infiltration 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 promoting facility in which a plurality of layers having different water permeability and water retention properties 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 comprising a glass foam layer made of glass foam buried underground, and a bamboo chip layer made of bamboo chips stacked on the glass foam layer and exposed on the ground surface.

[0009] The underground water storage, infiltration, and water retention structure according to the present invention is characterized by comprising: a glass foam layer made of glass foam buried underground; a soil layer made of soil stacked on top of the glass foam layer; and a bamboo chip layer made of bamboo chips stacked on top of the soil layer and exposed on the ground surface. [Effects of the Invention]

[0010] The underground water storage, infiltration, and water retention structure according to this invention comprises a glass foam layer made of glass foam buried underground, and a bamboo chip layer made of bamboo chips stacked on top of the glass foam layer and exposed on the ground surface. The glass foam layer and bamboo chip layer are relatively easy to obtain, resulting in low cost, and the structure is simple due to the small number of constituent parts. Furthermore, because the glass foam layer is porous with a high void ratio, it can store a large amount of rainwater underground. The glass foam layer is the layer below the bamboo chip layer exposed on the ground surface and is buried underground, so rainwater penetrates deeper into the glass foam layer, which has a higher water adsorption rate than the bamboo chip layer. Therefore, it can suppress rainwater runoff and tree root uplift.

[0011] Furthermore, the bamboo chip layer offers superior shock absorption, durability, and comfort compared to conventional asphalt, thus providing a better walking environment for pedestrians.

[0012] The water storage, infiltration, and water retention structure in the ground according to this invention comprises a glass foam layer made of glass foam buried in the ground, a soil layer made of soil stacked on top of the glass foam layer, and a bamboo chip layer made of bamboo chips stacked on top of the soil layer and exposed on the ground surface. The stacking of soil layers 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. [Brief explanation of the drawing]

[0013] [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. [Modes for carrying out the invention]

[0014] Hereinafter, a water storage, infiltration, and water retention structure in the ground according to an embodiment of the present invention (hereinafter simply referred to as the "water storage, infiltration, and water retention structure") will be described based on the drawings. Figure 1 shows a schematic cross-section of the water storage, infiltration, and water retention structure 1.

[0015] As shown in FIG. 1, the water storage and infiltration water retention structure 1 is, for example, a plurality of laminated structures that constitute the ground such as a sidewalk, a tree planting strip, or a parking lot. Specifically, the water storage and infiltration water retention structure 1 is composed of three layers. The water storage and infiltration water retention structure 1 is composed of a glass foam layer 2 buried in the ground, a soil layer 3 laminated on the glass foam layer 2, and a bamboo chip layer 4 laminated on the soil layer 3. Therefore, in the water storage and infiltration water retention structure 1, the glass foam layer 2 is formed at the deepest position among the three layers, and the bamboo chip layer 4 is the shallowest and exposed on the ground surface. The glass foam layer 2 functions as a functional layer for storing and infiltrating rainwater, the soil layer 3 functions as a growth base for the tree 10, and the bamboo chip layer 4 forms a walking surface and has a function of guiding rainwater to the lower layer.

[0016] The glass foam layer 2 is composed of glass foam. The glass foam is, for example, cullet recovered from waste glass such as glass containers and glass products. The glass foam has a porous structure with fine voids and is lightweight. Specifically, the characteristics of the glass foam are as follows.

[0017] Dry specific gravity 0.67 - 0.78 g / cm , -5 ,

[0019] , , , ,

[0018] , , 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%

[0018] The soil layer 3 is, for example, organic soil containing natural fertilizers such as fallen leaves. The bamboo chip layer 4 is, for example, bamboo cut from abandoned bamboo forests, etc., which has been crushed and pulverized.

[0019] The depths (thicknesses) of each of the layers 2, 3, and 4 are arbitrary. For example, the glass foam layer 2 is 1 to 100 cm, the soil layer 3 is 1 to 100 cm, and the bamboo chip layer 4 is 1 to 50 cm.

[0020] According to the water storage, infiltration, and water retention structure 1 described above, the following effects are achieved.

[0021] Due to the glass foam layer 2 having a porous structure with a high porosity, it can temporarily store a large amount of rainwater, etc. in the ground and has water permeability to guide it to the deep part of the ground. Therefore, the surface runoff of rainwater can be suppressed. Also, since air is retained in the voids of the glass foam layer 2, a good ventilation environment can be ensured around the roots of the tree 10. Moreover, the glass foam constituting the glass foam layer 2 has the physical and chemical properties necessary for practical use as a planting base aggregate, so it functions as a growth base for the tree 10. Furthermore, the glass foam layer 2 guides rainwater to the deep part of the ground without retaining it near the surface, and has a void structure that allows the roots of the tree 10 to extend to the inside, so the roots of the tree 10 can be guided to a deep position in the ground. As a result, the concentration and elongation of the roots of the tree 10 in the shallow layer can be suppressed, so the root heaving, the uplift of the paving surface, and the exposure of the roots can be suppressed. Additionally, even when the ground (such as a sidewalk or a parking lot) is subjected to trampling by vehicles or pedestrians after the start of its use, the growth of the tree 10 is less likely to be inhibited, and maintenance management can be easily carried out.

[0022] Since the soil layer 3 can contain sand, fertilizer, etc., its water retention and fertilizer retention properties are improved, and it can retain the nutrients necessary for the growth of the tree 10. Also, since the soil layer 3 can cooperate with the glass foam layer 2 to retain rainwater, it is easy to supply water to the tree 10 even after rainfall.

[0023] The impact absorption of the bamboo chip layer 4 is half that of ordinary asphalt. Therefore, it puts less strain on pedestrians' legs and hips. In addition, the surface temperature of the bamboo chip layer 4 is more than 10°C lower than that of ordinary asphalt. This means that there is less reflection of sunlight, creating a cool and comfortable environment for pedestrians. Furthermore, bamboo chips are robust and less susceptible to degradation from ultraviolet rays, making them less prone to cracking and abrasion. Moreover, weeds do not easily grow on the bamboo chip layer 4, and it is less slippery even when it rains. In addition, the bamboo chip layer 4 temporarily holds rainwater and allows it to permeate to the lower layer, thus suppressing rainwater runoff from the ground surface and promoting its penetration into the glass foam layer 2.

[0024] 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, which reduces the burden of maintenance and enables water conservation.

[0025] In addition, other embodiments of this invention do not have a soil layer. Therefore, in this embodiment, a bamboo chip layer is laminated on top of a glass foam layer.

[0026] 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]

[0027] 1. Water storage, infiltration, and water retention structure (Underground water storage, infiltration, and water retention structure) 2. Glass foam layer 3. Soil layer 4. Bamboo chip layer 10 Trees

Claims

1. A layer of glass foam, composed of glass foam buried underground, It has a bamboo chip layer that is exposed to the ground surface and is made of bamboo chips laminated on top of the glass foam layer, A water storage, infiltration, and water retention structure in the ground characterized by the following features.

2. A layer of glass foam, composed of glass foam buried underground, A soil layer composed of soil layered on top of the aforementioned glass foam layer, The system comprises a layer of bamboo chips, which is stacked on top of the soil layer and is exposed to the ground surface, A water storage, infiltration, and water retention structure in the ground characterized by the following features.

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