JP7557779B2 - Underground drainage device and underground drainage structure - Google Patents

Description

The present invention relates to an underground drainage device and an underground drainage structure that can smoothly drain groundwater without clogging due to particles such as soil and sand.

For example, Patent Documents 1 and 2 are known as technologies for draining groundwater that has seeped into the ground. The "drainage pipe" in Patent Document 1 is a drainage pipe that is buried in the ground to drain water that has seeped into the ground, and is configured with numerous slit-shaped water passage holes that extend in the axial direction on the circumferential surface.

The "underground water collection pipe" of Patent Document 2 aims to provide a water collection pipe that is less likely to clog and is easy to manufacture with low manufacturing costs, and is made of a perforated plate with an opening ratio of 5 to 50%.

Japanese Utility Model Application Publication No. 4-37624 JP 2003-232028 A

Groundwater that seeps into the earth is cloudy because it is mixed with particles of soil, sand, and other matter. Some of these particles float in the water, but they are heavier in specific gravity than water and sink.

The background art aims to drain water from the soil without clogging the holes by adjusting the shape, number and opening ratio of the holes.

However, when groundwater flows into drainage pipes or collection pipes, it is inevitable that the holes will be blocked by particles such as soil and sand that flow in along with the groundwater, causing clogging. In addition, the weight of the particles that flow into the inside of the drainage pipes causes them to settle and accumulate inside the pipes, causing the drainage pipes themselves to become clogged, and they are unable to continue to perform their functions of drainage and collection.

The present invention was devised in consideration of the above-mentioned problems with the conventional technology, and aims to provide an underground drainage device and an underground drainage structure that can smoothly drain groundwater without clogging due to particles such as soil and sand.

The underground drainage device of the present invention is an underground drainage device for draining groundwater that has infiltrated into the ground, and is characterized by comprising a pipe material that is formed with a hollow interior and is inserted into the ground in a diagonally downward position along the length of the pipe material, a water passage part that is a hole-shaped hole formed through the pipe wall and whose lower edge appears when the pipe material is in a diagonally downward position, and a cover part that is provided on the pipe material from the lower edge position of the water passage part along the length of the pipe material so as to cover the water passage part with respect to the ground, and that defines an inlet that opens into the ground between the lower edge and the cover part.

The water passage portion is characterized in that at least one water passage portion is formed in the pipe material.

The covering portion is characterized in that it is integrally formed with the pipe material by partially bulging the pipe wall outward from the pipe material.

The pipe material is composed of two pipe parts that are hollow inside and have their longitudinal ends butted together, and a connection part that is hollow and tubular and surrounds the butted parts of the pipe parts from the outside and connects the pipe parts together, the water passage part is a notch that is provided at the longitudinal end of at least one of the pipe parts and is formed into a hole shape by butting the longitudinal end of the other pipe part, and the cover part is provided on the connection part along the longitudinal direction of the pipe parts.

The underground drainage structure of the present invention uses the above-mentioned underground drainage tool, which is inserted into the ground with the inlet and the pipe facing diagonally downward, and is positioned so that the diagonally downward tip of the pipe is exposed from the ground to the ground surface as the insertion end.

The underground drainage device and underground drainage structure of the present invention can smoothly drain groundwater without clogging due to granular particles such as soil and sand.

1 is an explanatory diagram illustrating a preferred embodiment of an underground drainage device and an underground drainage structure according to the present invention. FIG. 2A and 2B are diagrams for explaining the underground drainage device shown in FIG. 1, in which (A) is a side cross-sectional view, and (B) is a cross-sectional view taken along line AA in FIG. 2A. 2 is an explanatory diagram for explaining the operation of the underground drainage device and the underground drainage structure shown in FIG. 1 . FIG. 4A and 4B are diagrams for explaining a modified example of the underground drainage device according to the present invention, in which (A) is a side cross-sectional view, and (B) is a cross-sectional view taken along line BB in FIG. 4A.

Below, a preferred embodiment of the underground drainage device and underground drainage structure of the present invention will be described in detail with reference to the attached drawings.

The underground drainage device 1 according to this embodiment is composed of a long pipe material 2, and is basically inserted into a drilled hole 3 formed by pre-boring as shown in FIG. 1, and is used to drain groundwater w that has infiltrated into the ground E.

The pipe material 2 of the underground drainage device 1 is inserted into the ground E in a diagonally downward position along its length, and the end 2a of the pipe material 2, which is the end of the insertion, is positioned so that it is exposed from the ground E to the ground surface G, thereby forming the underground drainage structure 6 according to this embodiment.

As shown in Figures 1 and 2, the pipe material 2 constituting the underground drainage device 1 according to this embodiment is formed to be hollow inside from one end to the other in the length direction, thereby forming a hollow passage 7 for circulating groundwater w. It is desirable to seal the end 2b of the pipe material 2 inserted into the drilled hole 3 to prevent the inflow of granular material such as soil and sand into the hollow passage 7.

The pipe material 2 is molded, for example, from a hard resin material such as polyvinyl chloride, which has excellent moldability and processability.

As shown in FIG. 2, the pipe material 2 has a water passage hole 4 formed in the shape of a square hole penetrating the pipe wall 2c of the pipe material 2 as a water passage portion for connecting the hollow passage 7 inside the pipe material 2 to the outside of the pipe material 2, i.e., to the ground E into which the pipe material 2 is inserted. The shape of the hole of the water passage hole 4 is not important.

The pipe material 2 is provided with a cover portion 5 by integral molding, positioned at the position of the water passage hole 4. The cover portion 5 covers the square hole-shaped water passage hole 4 from three sides, namely, one end edge (upper edge 4a described below) in the longitudinal direction of the pipe material 2 and both left and right end edges 4b in the circumferential direction, from the ground E. In other words, it is formed in a form that blocks the water passage hole 4 from the ground E.

The cover portion 5 is formed so that when the pipe material 2 is in a diagonally downward position and the upper edge 2a and lower edge 2c appear in the rectangular water passage hole 4 in the longitudinal direction of the pipe material 2, the cover portion 5 extends from the lower edge 4c of the water passage hole 4 along the longitudinal direction of the pipe material 2 to at least the upper edge 4a. In other words, the lower edge 4c of the water passage hole 4 and the lower edge 5a of the cover portion 5 are in a so-called flush relationship.

The lower edge 5a of the cover 5 is opened toward the ground E at the lower edge 4c of the water passage 4, between the lower edge 4c and the cover 5, to define an inlet 8 through which groundwater w flows toward the water passage 4. This inlet 8 is connected by the cover 5 to the water passage 4, and is also connected to the hollow passage 7.

In this embodiment, the cover portion 5 is integrally formed by partially increasing the inner diameter of the pipe wall 2c of the pipe material 2, i.e., at the position of the water passage hole 4, and bulging it outward from the pipe material 2. This forms a groove-shaped portion 5b that faces the water passage hole 4 and allows water to pass through.

At least one set of water passage hole 4 and covering portion 5 is formed in pipe material 2. In the example shown in Figure 2, four sets of water passage hole 4 and covering portion 5 are provided at intervals in the circumferential direction of pipe material 2.

The sets of water holes 4 and cover parts 5 may be arranged so that adjacent ones are offset from each other in the circumferential direction.

The sets of water holes 4 and cover parts 5 may be provided in multiple stages spaced apart along the length of the pipe material 2. In the example shown in FIG. 1, the sets of water holes 4 and cover parts 5 are provided in two stages. This allows groundwater w to be discharged from multiple positions with different insertion depths into the ground E.

By using the underground drainage device 1 according to this embodiment and inserting it into the ground E, an underground drainage structure 6 according to this embodiment is formed, as shown in FIG. 1.

The underground drainage tool 1 is inserted into a pre-bored hole 3 and placed underground E. The pre-bored hole 3 is formed diagonally upward with respect to the horizontal in the underground E at the insertion point of the pipe material 2, and the underground drainage tool 1 is inserted in a position such that the inlet 8 formed by the pipe material 2 and the cover part 5 faces diagonally downward in the insertion direction (the length direction of the pipe material 2) (see "Tilt angle" in Figure 1).

Then, the end of the pipe material 2 facing diagonally downward (the hollow passage 7 opens diagonally downward) located diagonally downward on the opposite side to the insertion end 2b located diagonally upward in the ground E is positioned as the insertion termination 2a so as to be exposed from the ground E to the ground surface G in order to connect the hollow passage 7 to the outside of the ground surface G.

As shown in FIG. 1, the insertion end 2a of the pipe material 2 is cut along the cut surface along the ground surface G so that it does not appear as a protrusion on the ground surface G.

The operation of the underground drainage tool 1 and underground drainage structure 6 according to this embodiment will now be described. As described above, the underground drainage tool 1 is inserted into the ground E with the inlet 8 and the pipe material 2 facing diagonally downward into the drilled hole 3 formed diagonally upward with respect to the horizontal in the ground E at the insertion point of the pipe material 2. Then, the diagonally downward tip of the pipe material 2 is exposed from the ground E to the ground surface G as the insertion end 2a.

Regarding the discharge of groundwater w by the underground drainage device 1, as the water pressure in the ground E increases, the groundwater w carrying particles such as soil and sand moves toward the void in the ground E.

The inlet 8 in the cover 5 of the underground drainage device 1 according to this embodiment and the water passage 4 connected to the inlet 8 are voids in the soil, and as shown in FIG. 3, groundwater w flows in together with particles such as soil and sand. Also, if there is soil or sand particles around the inlet 8, the groundwater w in the vicinity is guided to the inlet 8 by capillary action.

When the underground drainage device 1 is inserted into the ground E, the inlet 8 faces diagonally downward, so that particles such as soil and sand that are heavier in specific gravity than water contained in the groundwater w settle and remain on the underground E side outside the inlet 8, while the groundwater w, although it contains suspended solids, overflows as the supernatant through the inlet 8 from the water passage 4 and flows into the hollow passage 7 of the pipe material 2.

The pipe material 2 is inserted obliquely downward so that groundwater w naturally flows from a higher point to a lower point toward the ground surface G, and the flowing groundwater w is discharged from the insertion end 2a toward the ground surface G through the hollow passage 7 of the pipe material 2.

As a result, the underground drainage device 1 according to this embodiment can smoothly and efficiently drain groundwater w from the underground E at and around the insertion point of the underground drainage device 1 without clogging due to granular matter such as soil and sand.

In the above embodiment, a single pipe material 2 is used as the underground drainage device 1, but it is of course possible to connect multiple pipe materials 2 and form a long underground drainage device 1 by connecting their hollow passages 7 using extension parts that connect the pipe materials 2 together.

Figure 4 shows a modified version of the above embodiment. In the above embodiment, the cover portion 5 is provided on the pipe material 2, but in this modified underground drainage device 1, a single pipe material is used as the pipe material part 10, multiple pipe material parts 10 are extended and connected with connection parts 9, and the cover portion 5 is provided on the connection parts 9.

The underground drainage device 1 is composed of two pipe parts 10A, 10B that are hollow inside and have their longitudinal ends butted together, and a connection part 9 that is hollow and cylindrical and surrounds the butted parts of the pipe parts 10A, 10B from the outside, and connects the pipe parts 10A, 10B together.

The illustrated example shows a configuration consisting of two pipe parts 10A, 10B and one connection part 9.

The underground drainage device 1 may be configured to have a long length in which multiple pipe parts 10A, 10B are connected in the longitudinal direction of the pipe parts 10A, 10B by multiple connection parts 9, with the pipe parts 10A, 10B being connected in sequence with the connection parts 9.

The connection part 9 has a first connection part 9A at one end in the length direction into which one of the two pipe parts 10A, 10B, 10A, is inserted and connected, and a second connection part 9B at the other end in the length direction into which the other pipe part 10B, 10B, 10A, ...

The pipe parts 10A and 10B are butted together and connected to each other to form a continuous hollow passage 7.

In this modified example, the water passage hole 4 as the water passage section is formed in at least one of the two pipe parts 10A, 10B connected by the first connection part 9A and the second connection part 9B, in the illustrated example, in the longitudinal end part of the pipe part 10B connected to the second connection part 9B, and is composed of a notch 11 in the form of a hole formed by butting together the longitudinal end part of the pipe part 10A connected to the first connection part 9A (indicated by the symbol x in the figure).

The notch 11 may be formed in the pipe part 10A connected to the first connection part 9A instead of the pipe part 10B connected to the second connection part 9B.

Alternatively, the notches 11 may be formed in both of the two pipe parts 10A, 10B. In this case, it is desirable to displace the positions of the notches 11 of each pipe part 10A, 10B in the circumferential direction of the pipe parts 10A, 10B so that the notches 11 of one pipe part 10A, 10B are aligned with the longitudinal end of the other pipe part 10B, 10A (see the symbol x in the figure). By forming the notches 11 in the two pipe parts 10A, 10B, it is also possible to provide the water passage hole 4 from the first connection part 9A to the second connection part 9B.

The cover portion 5 is provided on the connection part 9 along the length direction of the pipe parts 10A and 10B. The cover portion 5 is disposed at the position of the water passage hole 4 and is integrally molded on the connection part 9.

As in the above embodiment, the cover portion 5 is formed in such a way that it covers the hole-shaped water hole 4 from three sides, the upper edge 4a in the longitudinal direction of the pipe parts 10A and 10B facing diagonally downward and the left and right end edges 4b in the circumferential direction, with the condition that the lower edge 4c of the water hole 4 and the lower end edge 5a of the cover portion 5 are in a so-called flush relationship.

In the illustrated example, the cover portion 5 is arranged to cover the notch 11 of the pipe part 10B connected to the second connection portion 9B.

When the water passage hole 4 is provided from the first connection part 9A to the second connection part 9B, the cover part 5 is formed longer than in the illustrated example so as to cover the notch 11 of the pipe part 10A connected to the first connection part 9A.

The lower edge 5a of the cover 5 is opened toward the ground E at the lower edge 4c of the water passage 4, between the lower edge 4c and the cover 5, to define an inlet 8 through which groundwater w flows toward the water passage 4. This inlet 8 is connected to the water passage 4 by the cover 5, and is also connected to the hollow passage 7.

Even in this modified example, the cover 5 is integrally molded by partially increasing the inner diameter of the pipe wall 9a of the connection part 9, i.e., at the water passage hole 4 position, by bulging the wall outward from the connection part 9. This forms a water-passing groove 5b that faces the water passage hole 4 and allows water to pass through.

The rest of the configuration is the same as in the above embodiment, and it goes without saying that this modified example provides the same effects as the above embodiment.

REFERENCE SIGNS LIST 1 Underground drainage device 2 Pipe material 2a Insertion end of pipe material 2c Pipe wall of pipe material 4 Water passage hole 4c Lower edge of water passage hole 5 Covering part 6 Underground drainage structure 8 Inlet 9 Connection part 10A, 10B Pipe material part 11 Notch E Underground G Ground surface w Groundwater x Butt joint of pipe material parts

Claims (4)

An underground drainage device for draining groundwater that has infiltrated into the ground,
A pipe material that is formed with an inside hollow and is inserted into the ground in a diagonally downward position along a length direction;
A water passage portion having a hole shape formed through a pipe wall of the pipe material, the lower edge of which appears when the pipe material is in a diagonally downward position;
the pipe material is provided with a cover portion that is provided along the length of the pipe material from the lower edge position of the water passage portion so as to cover the water passage portion with respect to the ground, and that defines an inlet opening toward the ground between the lower edge and the cover portion ;
The pipe material is composed of two pipe material parts formed with a hollow interior and having longitudinal ends butted against each other, and a connection part formed in a hollow cylindrical shape surrounding the butted parts of the pipe material parts from the outside and connecting the pipe material parts to each other,
The water passage portion is a notch provided at a longitudinal end portion of at least one of the pipe parts, and is formed into a hole shape by abutting the longitudinal end portion of the other pipe part,
The underground drainage device is characterized in that the cover portion is provided on the connection part along the longitudinal direction of the pipe material part . The underground drainage device according to claim 1, characterized in that at least one water passage portion is formed in the pipe material. 3. The underground drainage device according to claim 1, wherein the cover portion is integrally formed with the connection part by partially swelling a pipe wall of the connection part outwardly of the connection part . An underground drainage structure comprising: an underground drainage device according to any one of claims 1 to 3 ; the underground drainage device is inserted into the ground with the inlet and the pipe facing diagonally downward; and the diagonally downward tip of the pipe is positioned so that it is exposed from the ground to the ground surface as the insertion end.

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