JP2002004393A - Device for returning surface water to underground - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a large quantity of surface water to be returned to underground. SOLUTION: This device is provided with a water catchment member 10, a drainage pipe 20, a filter 40, and a check valve 50. The catchment member 10 is formed with an upper opening part 11a whereinto the surface water flows and provided with an outflow hole 12a formed in a bottom wall 12. The drainage pipe 20, which is a hollow pile whose upper end is coupled to the outflow hole 12a of the catchment member 10, passes through the first permeable layer B and the impermeable layer C of ground to reach at least the second permeable layer D and allows a periphery-of-pile wall corresponding to the permeable layers B and D to have water permeability. The filter 40 makes the surface water discharged into the drainage pipe 20 cleaned. The check valve 50 is closed only when hydraulic pressure within the drainage pipe 20 attains at least atmosphere pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is intended to restore underground water such as rainwater and snowmelt to underground where underground water is reduced or depleted in, for example, an urban area or an industrial area, thereby recovering the underground environment and preventing flooding of the surface. It relates to a planned underground water reduction device for surface water.

[0002]

2. Description of the Related Art In urban areas, the surface of roads and the like is paved with asphalt and concrete, so that surface water such as rainwater and snowmelt cannot penetrate underground. Therefore, for example, in the case of a large amount of rainwater in the rainy season, the inundation of the ground surface is prevented by treating the wastewater by draining it to a sewage system or a river. As a result, groundwater is reduced or depleted, which causes various problems such as land subsidence, increase in underground temperature, and destruction of a breeding environment for plants and the like.

Therefore, Japanese Patent Laying-Open No. 57-77737 proposes a water passage side groove 100 as shown in FIGS. The water passage side groove 100 connects the upper end of the water passage pile 120 to the bottom of the U-shaped groove 110, and connects the lower end of the water passage pile 120 to the free groundwater aquifer (first (One permeable layer) B, and the U-shaped groove 11
Surface water such as rainwater that has flowed into the
This is an invention having a configuration in which the first water-permeable layer B is reduced to the first water-permeable layer B through the zero.

[0004]

However, the above-mentioned Japanese Patent Application Laid-Open No.
In the gutter 100 for water passage disclosed in Japanese Patent Application Laid-Open No. 7-77737, the surface water is reduced to only the first permeable layer B. Therefore, when the groundwater in the first permeable layer B becomes saturated, the surface water is removed. As described above, there is a problem that the water cannot be drained to the first permeable layer B. Further, when the groundwater in the first permeable layer B becomes saturated and the rainfall continues further, the drainage from the U-shaped groove 110 to the sewage system or the river cannot be made in time, and the ground surface A is flooded. There was also the problem of getting lost.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and is capable of returning a large amount of surface water to an underground in an urban area where groundwater is insufficient or depleted, thereby restoring the underground environment and flooding the surface. It is an object of the present invention to provide an underground water recirculation device that can reduce not only the burden on sewage facilities but also the prevention of flooding of rivers, as well as prevention.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the gist of the present invention is to provide a method in which surface water, such as rainwater, flows underground in a ground where a permeable layer and an impervious layer alternate from the surface to the ground. A water collecting member buried in the vicinity of the ground surface of the ground, and formed of a side wall forming an upper opening through which the surface water flows and a bottom wall forming an outflow hole of the surface water, A hollow pile in which an upper end opening is connected to an outflow hole of the water collecting member, penetrates the first permeable layer and the impermeable layer of the ground, reaches at least the second permeable layer, and at least the first and second permeable layers. A waterfall pipe having water permeability on the pile peripheral wall corresponding to each of the two water-permeable layers, an upper filter for purifying the surface water drained to the waterfall pipe, and only when the water pressure in the waterfall pipe becomes higher than the atmospheric pressure. A ground characterized by having a check valve for closing In the basement reduction device, and the like of the water.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an underground water reduction apparatus according to an embodiment of the present invention will be described with reference to the drawings.
1 to 3, reference numeral 1 denotes a surface water underground reduction device according to the present embodiment, and the underground reduction device 1 mainly includes a water collecting member 10, a water pipe 20, an upper filter 40, and a check valve 50.
It is composed of

Reference numeral 10 denotes a water collecting member, which in this embodiment is a concrete waterway block. The water collecting member includes a pair of side walls 11, 11 forming an upper opening 11a into which surface water flows, and a surface water outflow hole 12a. A plurality of the waterway blocks 10 are buried in a connected state in the vicinity of the surface S of the ground, so that the downstream side forms a waterway leading to a sewage system or a river. Has become.

Reference numeral 20 denotes a waterfall pipe, which is formed by a hollow pile. The upper end of the hollow pile 20 is inserted into the outflow hole 12a of the waterway block 10 and connected to the bottom wall 12, and the upper end opening is formed. 20A is located in the waterway block 10. Further, the lower end portion penetrates through the capillary layer A, the free groundwater aquifer (first permeable layer) B, and the upper pressurized layer (first impermeable layer) C, respectively, so as to pressurize the groundwater aquifer (second permeable layer). Layer D), and the pile peripheral wall of the hollow pile 20 located at the first water permeable layer B and the second water permeable layer D is configured to have water permeability. In the drawing, reference numeral 20B denotes a lower end closed portion of the hollow pile 20.

More specifically, the water pipe 20 is formed by alternately connecting a water-impermeable concrete hollow pile 21 and a water-permeable porous concrete hollow pile 22A, 22B via a weldless joint 30. The hollow pile 21 made of water-impermeable concrete is provided in the capillary zone A and the first water-impermeable layer C, and the hollow pile 22 made of porous concrete.
A and 22B correspond to the first permeable layer B and the second permeable layer D, respectively. In addition, E in the figure is a lower pressure layer (second impermeable layer).

Reference numeral 30 denotes a non-welded joint, as shown in FIG.
A split inner ring 3 having an inward projection 31b for sandwiching the end plates 21a, 22a of the hollow piles 21, 22, A, 22B.
1, 31 and an annular outer ring 32 for restraining the inner ring 31 from the outside. The outer surface of the inner ring 31 and the inner surface of the outer ring 32 have tapered surfaces 31a inclined in opposite directions. , 32a are formed respectively, and concavo-convex grooves that mesh with each other are formed in the respective tapered surfaces 31a, 32a.

Reference numeral 40 denotes an upper filter, which in the present embodiment is constituted by a hemispherical wire mesh, is removably attached to an upper part of a check valve 50 described later, and is a surface water drained into the drain pipe 20. To remove earth and sand, trash, etc.
This is to prevent groundwater pollution. Therefore, the shape and the material are not particularly limited.

Reference numeral 50 denotes a check valve, which is detachably attached to the upper end opening 20A of the water pipe 20, as shown in FIG. 3, when the water pressure in the water pipe 20 becomes higher than the atmospheric pressure. The check valve 50 is mainly constituted by a main body 51 and a valve body 55 by preventing backflow of water from inside the waterfall pipe 20 to the water collecting member 10.

More specifically, in FIG. 3, reference numeral 51 denotes a main body which is connected to a large-diameter cylindrical portion 51a having an outer diameter substantially equal to the outer diameter of the water-fall pipe 20, and a lower portion of the large-diameter cylindrical portion 51a. The small-diameter cylindrical portion 51b has a smaller diameter than that of the small-diameter cylindrical portion 51b, and the inner peripheral surface of the lower end opening 51c of the small-diameter cylindrical portion 51b is formed in an inverted funnel shape.

Numeral 55 denotes a valve body which is an inverted funnel-shaped valve 5 having the same cross section as the lower end opening 51c of the small diameter cylindrical portion 51b.
5a and a shaft 5 extending upward from the upper end of the valve 55a
5b. The upper end of the shaft 55b passes through an insertion hole formed in the center of the water-permeable plate 52, which will be described later, and the nut (stopper) 54 is screwed into the threaded portion. It is attached to the water permeable plate 52.

Accordingly, the valve body 55 is
1 is vertically movable along the vertical center axis of the small-diameter cylindrical portion 51b, and normally moves down by its own weight and is in a state shown by a solid line, and the water pressure in the water-falling pipe 20 becomes equal to or higher than the atmospheric pressure. When the valve body 55 moves upward, the outer peripheral surface of the valve 55a and the inner peripheral surface of the lower end opening 51c of the small diameter cylindrical portion 51b come into close contact with each other, and the lower end opening 51c is closed by the valve 55a. Will function as

Numeral 52 denotes a water permeable plate which is installed by being dropped into the upper end opening of the large-diameter cylindrical portion 51a. The water permeable plate 52 has a large number of water permeable holes 52a. In addition,
In this embodiment, the upper part of the check valve 50 serving as the drainage of surface water is configured to protrude above the bottom wall 12 of the waterway block 10. With this configuration, the waterway block 1
The sediment and the like in the surface water that has flowed into the surface water is settled on the bottom wall 12, and the sediment is caused to flow down by the water flow flowing down the waterway block 10. After each filtration at 52, the water is poured into the water pipe 20 via the check valve 50.

Next, the operation of the underground water reduction apparatus 1 according to the present embodiment will be described. For example, a large amount of rainwater (surface water) in the rainy season or the like is transmitted from the surface portion S to the waterway block 1.
It flows into 0 and flows down in the water channel. During this time,
When the level of the rainwater flowing in the waterway block 10 rises above the check height of the check valve 50, the rainwater is drained into the drain pipe 20 via the upper filter 40 and the check valve 50.

The rainwater drained into the waterfall pipe 20 passes through the porous concrete hollow pile 22B below the waterfall pipe 20 to the second water permeable layer D via the permeable peripheral wall of the pile and the middle part of the waterfall pipe 20. The porous concrete hollow pile 22A is reduced to the first permeable layer B via the pile peripheral wall having water permeability. The reduced water flows to the side through the first water permeable layer B and the second water permeable layer D having good water permeability, and becomes free groundwater in the first water permeable layer B. In this area, it becomes confined groundwater.

Here, the free groundwater and the confined groundwater in the first permeable layer B and the second permeable layer D may become saturated, and in particular, the confined groundwater in the second permeable layer D becomes saturated. In this case, it is conceivable that the pressurized groundwater flows backward through the waterfall pipe 20 and overflows from inside the waterfall pipe 20 into the waterway block 10. In such a case, the valve 55a of the valve body portion 55 constituting the check valve 50 is pressed upward from below by the backflow water, and as shown by the arrow in FIG. Move up to the state shown.

As a result, the outer peripheral surface of the valve 55a and the inner peripheral surface of the lower end opening 51c of the small-diameter cylindrical portion 51b come into close contact with each other, and the lower end opening 51c is closed by the valve 55a. Backflow of water to 10 is prevented. afterwards,
When the groundwater in the first permeable layer B and the second permeable layer D is insufficient or depleted, the upward pressing force on the valve 55a is released, and the valve 55a moves down to the state shown by the solid line in FIG. Drainage of rainwater from the waterway block 10 into the water pipe 20 is restarted.

FIG. 5 shows another embodiment of the water pipe 20. In the figure, reference numeral 60 denotes the ground surface S
A hollow pile with a closed end having a length that reaches the second permeable layer D from the vicinity, is entirely formed of impervious ordinary concrete, and the nodes 61 and the pile peripheral wall 62 are alternately formed. It has a structure that is repeated continuously.

The pile peripheral wall 62 installed at a position corresponding to the first water permeable layer B and the second water permeable layer D of the knotted hollow pile 60 has a large number of water permeable holes 62a. When the water permeability is given, the outer peripheral surface of the pile peripheral wall 62 in which the water permeation hole 62a is formed is attached to the lower filter 6.
3. The outer diameter of the lower filter 63 is desirably formed to be smaller than the outer diameter of the knot portion 61. Damage can be prevented.

In the above embodiment, the water collecting member 10 is a concrete waterway block composed of a pair of opposed side walls 11, 11 and a bottom wall 12. However, the water collecting member 10 is not limited to the waterway block. The object of the present invention can be achieved even with a square block having a bottom wall. In addition,
At the time of maintenance of the device of the present invention, the check valve 50 is removed together with the filter 40 from the upper end opening 20A of the water drop pipe 20, and a jet water stream is jetted from a rod (not shown) inserted into the water drop pipe 20, so that the inside of the water drop pipe 20 is easily formed. Can be washed.

According to the underground water reduction apparatus 1 of the present embodiment as described above, the portion of the waterfall pipe 20 corresponding to the first permeable layer B and the second permeable layer D has water permeability.
A large amount of surface water can be reduced to the permeable layers B and D whose groundwater has been reduced or depleted. As a result, land subsidence and the recovery of the underground environment can be achieved, and even if heavy rainfall continues, the burden on sewerage facilities can be reduced and flooding of rivers can be prevented. It can be reliably prevented.

Further, even if the groundwater reduced to the second permeable layer D is pressurized by the impermeable layer (upper pressurized layer) C and becomes saturated, the backflow of the pressurized groundwater through the drainage pipe 20 is performed. Can be reliably prevented by the check valve 50, and flooding of the ground surface S due to the backflow of the groundwater can also be prevented.

[0027]

The underground water reduction apparatus according to the present invention has the following features.
With the above configuration, a large amount of surface water can be returned underground in an urban area where the groundwater has been reduced or depleted, and not only the restoration of the underground environment and prevention of flooding of the surface, but also sewage facilities This has the effect of reducing the burden on the river and preventing flooding of the river.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a surface water underground reduction device according to an embodiment of the present invention.

FIG. 2 is an explanatory longitudinal sectional view showing a construction state of the apparatus.

FIG. 3 is a partially enlarged sectional view showing a main part of the device.

FIG. 4 is an enlarged half-sectional view showing a connection part of a water pipe in the apparatus.

FIG. 5 is a half sectional view showing another embodiment of a water pipe.

FIG. 6 is a perspective view showing a conventional water passage groove.

FIG. 7 is a longitudinal sectional view showing a construction state of the water passage gutter.

[Explanation of symbols]

 DESCRIPTION OF REFERENCE NUMERALS 1 Surface water underground reduction device 10 Water collecting member 11 Side wall 11a Upper opening 12 Bottom wall 12a Outlet hole 20 Dropping pipe 20A Upper opening 20B Lower closing 21 Concrete hollow pile 22A, 22B Porous concrete hollow pile 40 Upper filter 50 Check valve 51 Main body 52 Water permeable plate 52a Water permeable hole 55 Valve body 55a Valve 55b Shaft 60 Knotted hollow pile 61 Knot 62 Pile peripheral wall 62a Water permeable hole 63 Lower filter

Claims (8)

[Claims] 1. A device for reducing surface water, such as rainwater, to the underground in a ground where a permeable layer and an impermeable layer are alternately continuous from the ground to the ground, wherein the device is buried near the surface of the ground, A water collecting member comprising a side wall forming an upper opening into which the surface water flows and a bottom wall forming an outflow hole for the surface water, and a hollow pile having an upper end opening connected to the outflow hole of the water collecting member. A drain pipe that penetrates the first permeable layer and the impermeable layer of the ground, reaches at least the second permeable layer, and has water permeability on at least the pile peripheral wall corresponding to the first and second permeable layers, An upper filter for purifying the surface water discharged to the waterfall pipe, and a check valve that closes only when the water pressure in the waterfall pipe becomes equal to or higher than the atmospheric pressure. apparatus. 2. The underground water reduction apparatus according to claim 1, wherein the water collecting member is a concrete block made of four sides and a bottom wall. 3. The water collecting member according to claim 1, wherein the water collecting member is a concrete waterway block including a pair of opposed side walls and a bottom wall, and a plurality of the waterway blocks are connected to form a waterway. Underground reduction device for surface water. 4. The waterfall pipe according to claim 1, wherein the hollow pipe made of porous concrete having water permeability and the hollow pile made of water-impermeable concrete are connected to each other. Underground reduction device for surface water. 5. The method according to claim 1, wherein the water pipe is a hollow knotted pile made of concrete, and a large number of water-permeable holes are formed in a pile peripheral wall between the knots corresponding to the first and second permeable layers of the hollow knotted pile. 4. The underground water reduction apparatus according to claim 1, wherein the outer peripheral surface of the pile peripheral wall is covered with a lower filter. 6. The underground water reduction apparatus according to claim 5, wherein the lower filter has an outer diameter smaller than an outer diameter of a knot of the hollow peg. 7. A main body in which the check valve is coupled to a small-diameter cylindrical portion having an inverted funnel-shaped inner peripheral surface at a lower portion of a large-diameter cylindrical portion installed with the upper end opening of the water-fall pipe closed. When,
An inverted funnel-shaped valve body installed so as to be able to move up and down in the small-diameter cylindrical portion of the main body, and when the water pressure in the water-falling pipe becomes higher than the atmospheric pressure, the valve of the valve body is raised. The underground water reduction device according to claim 1, 2, 3, 4, 5, or 6, wherein the small diameter cylindrical portion is closed by moving. 8. The system according to claim 1, wherein the check valve and the upper filter are detachably mounted on an upper end opening of the water pipe. Underground water reduction equipment for surface water.