JP2617128B2 - Construction method of underground infiltration equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an underground infiltration device for preventing rainwater from flowing directly into a sewer pipe and penetrating into the ground to minimize rainwater outflow outside the area. It relates to a settlement construction method.

<Prior Art> Rainwater originally permeated the ground, but as urbanization progresses and the ground surface is covered with concrete or asphalt, the amount of rainwater that permeates the ground has decreased.

As a result, problems such as an increase in the amount of rainwater flowing out to the sewer system, a flow of water in a river or the like in a short time immediately after rainfall, and a decrease in the amount of groundwater causing ground subsidence have occurred.

Therefore, underground infiltration method is implemented to deal with these.

In this method, an apparatus as shown in FIG. 5 is used.

That is, it is a device having a structure in which a cylindrical cylinder a is buried in the ground, a PVC pipe b for taking in rainwater on the ground is introduced into the cylinder a, and water permeates into the permeation part c.

<Problems to be Solved by the Present Invention> The above-mentioned conventional underground infiltration apparatus has the following problems.

<A> The conventional underground infiltration apparatus excavates the ground using bentonite or earth retaining when the cylinder a is buried in the ground.

However, when bentonite is used, bentonite flows into the gap between the permeation layers in the surrounding ground, causing clogging of the permeated surface, reducing the amount of water permeated, and allowing the permeated amount to completely recover even after washing. It will be difficult.

In addition, when soil retaining is used, the aggregate structure of the soil on the infiltration surface of the surrounding ground is destroyed, and the amount of permeated water similarly decreases.

<B> Since the structure is such that the water is directly guided from the water collecting box on the ground to the permeation part c by the PVC pipe b, the filtration of water is insufficient.

 This causes clogging of the permeation surface.

<Object of the present invention> The present invention has been made in order to solve the above-mentioned problems, and it is possible to prevent clogging and destruction of the infiltration surface of the ground, and to infiltrate underground water efficiently. It is an object of the present invention to provide a method for constructing an apparatus.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

<A> Sedimentation tank (FIG. 1) The sedimentation tank 1 has a cylindrical straight wall 12 fixed to the upper surface of a floor plate 11, and an inclined wall 13 formed at the upper end of the straight wall 12 and having a diameter gradually reduced toward the upper part. Is fixed.

Floor plate 11, straight wall 12, slope wall 13 are formed of concrete or the like,
The structure will not leak water to surrounding mountains.

Then, a lid 14 that can be freely opened and closed is attached to the upper end of the inclined wall 13.

Further, the settling tank 1 is provided with a water collecting pipe 15 that communicates with the water collecting pit above the ground and the inside of the settling tank 1.

<B> Infiltration tank (Fig. 1) The infiltration tank 2 is constructed by assembling the liner plate 21 into a cylindrical shape.
The upper open end is attached to the lower surface of the floor plate 11 of the settling tank 1, and the lower open end is laid with crushed stone 27 in the upper layer and coarse sand 28 in the lower layer.

<C> Liner plate (FIGS. 1 and 3) The liner plate 21 is, as shown in FIG.
The plywood in which the corrugated plate 22 and the corrugated plate 23 are adhered is bent toward the corrugated plate 23 into an arc shape having a predetermined diameter.

The drainage plate 22 is located on the outer peripheral side of the permeation tank 2 and is made of a material having water permeability.

For example, a well-known styrodrene (manufactured by Mitsubishi Yuka Birdish Co., Ltd.) obtained by hardening expanded particles of expanded polyethylene with a special adhesive is used.

This styrodrene is lightweight and easy to handle, and has a water permeability similar to that of child gravel (k = 2.7 to 3.5 cm / sec) and is resistant to compression.

Further, the water that has permeated from one surface of the styrodren has a property of being widely dispersed and uniformly discharged when discharged from the other surface.

Next, the corrugated plate 23 is used to reinforce the drainage plate 22, and is formed by corrugating a steel plate or the like.

A drain hole 24 is opened in the corrugated plate 23, and a connection frame 26 having a connection hole 25 is attached to the periphery thereof.

When connecting the liner plates 21 to each other in a cylindrical shape,
It is preferable to insert a bolt 29 into the connection hole 25 and fasten it with a nut.

<D> Filtration pipe (FIG. 1) The filtration pipe 3 is a perforated pipe having water permeability.

The filtration pipe 3 is detachably attached to the floor plate 11 of the sedimentation tank 1 with a fixed band 31 or the like in a detachable vertical direction so that the interior of the sedimentation tank 1 communicates with the interior of the permeation tank 2.

In the case of attachment, it is desirable that the upper end of the filtration pipe 3 be raised about 60 cm from the floor plate 11 for attachment.

The lower end of the filter pipe 3 is closed and the upper end is open, and a filter cloth 32 is attached to the inner surface of the pipe.

At this time, a filter cloth 32 is also attached to the rising portion of the filtration pipe 3 on the floor plate 11 on the outer surface of the pipe to form a folded portion 33.

When the clogging substance adheres to the filter cloth 32 and the water permeability decreases, the fixing band 31 is removed, the filter pipe 3 is pulled out, and the filter cloth 32 may be replaced.

<Construction method of the present invention> Next, a settlement construction method of the underground infiltration device will be described.

When the sinking method is adopted, first, as shown in FIG. 2, the cutting edge 4 is attached to the lower end of the ring of the liner plate 21.

Then, by excavating the ground near the lower end in the ring while connecting the ring upward, the ring is settled by its own weight.

Care should be taken in excavation to protect the natural ground conditions as much as possible.

In addition, a water permeable sheet (not shown) is attached to the permeated side surface of the ground to prevent the inflow of fine particles.

It is desirable that the settlement be performed only by the own weight of the ring, but in practice, since the liner plate 21 is lightweight, it is difficult to settle by its own weight, so it is easy to sink by loading the ring, giving vibration, etc. To do.

At the time of settlement, various known caisson settlement methods can be employed.

After sinking to a predetermined depth to construct the infiltration tank 2, sand 28 is laid in the lower layer and crushed stone 27 is laid in the upper layer on the ground floor at the lower end of the infiltration tank 2.

At this time, sand 28 or the like is laid immediately after the excavation is completed so that the floor surface of the ground is not solidified by foot, and the floor is walked on.

At the upper end of the ring at the top, the filtration pipe 3 and the water collection pipe 15
The precipitating tank 1 equipped with the
Only the upper lid 14 is exposed on the ground.

In addition, the end of the above-ground portion of the water collecting pipe 15 is connected to a water collecting box or the like.

<Operation of the Present Invention> Next, the operation of the present invention will be described.

<B> Rainwater collected by the water collecting tank on the ground flows into the sedimentation tank 1 through the water collecting pipe 15.

When the water level in the sedimentation tank 1 is lower than the upper end of the filtration pipe 3, the water flows into the filtration pipe 3 from the side thereof.

At this time, since the folded portion 33 of the filter cloth 32 is attached to the outer surface of the filter pipe 3, the clogging substance in the water is filtered and adheres to the folded portion 33 and remains.

In addition, a large clogging substance precipitates and remains in the precipitation tank 1.

Further, when the amount of rainwater becomes large, the water overflows from the sedimentation tank 1 and flows out to the ground only by the inflow from the side of the filtration pipe 3. Is configured to flow in from the upper open end of the.

However, since the water flowing from the upper open end is also filtered by the filter cloth 32 attached to the inner surface of the filter pipe 3, only the water from which the clogging substance has been removed is finally contained in the permeation tank 2. Will flow in.

<B> The drainage plate 22 of the permeation tank 2 is formed of styrodrene.

Therefore, the water in the infiltration tank 2, as shown in FIG.
When it is discharged to the ground, it is widely dispersed and evenly discharged.

Therefore, it is possible to prevent the penetration surface of the ground from being destroyed.

<Effects of the Present Invention> Since the present invention has been described above, the following effects can be expected.

<B> The conventional construction method of the underground infiltration device is that when the cylinder is buried in the ground, the ground is excavated using bentonite or earth retaining, so clogging or destruction of the infiltration surface occurs, It reduces the amount of water permeation.

On the other hand, in the present invention, the infiltration tank can be constructed by the settlement method.

Therefore, at the time of construction, bentonite and soil retention become unnecessary, clogging and destruction of the infiltration surface can be prevented, and water can be efficiently infiltrated.

<B> The conventional underground infiltration apparatus has a structure in which water is directly guided from a water collecting pit on the ground to the infiltration section by a PVC pipe, so that water filtration is insufficient, which causes clogging of the infiltration surface.

However, in the present invention, a filtration pipe is provided, and after sufficiently filtering the rainwater on the ground, it can be drained to the infiltration surface.

Therefore, clogging of the permeating surface can be reliably prevented, and water can be efficiently permeated.

<C> For the drainage plate of the liner plate of the present invention, a material having water permeability and uniform drainage, such as styrodren, is used.

Therefore, when the water in the infiltration tank is discharged to the ground,
Widely dispersed and evenly discharged.

Therefore, it is possible to prevent the penetration surface of the ground from being destroyed.

<D> When the filter cloth of the filter pipe is clogged, the filter pipe can be removed and replaced easily.

 Therefore, water can always be sufficiently filtered.

<E> A corrugated plate is adhered to the inner peripheral surface of the liner plate.

Therefore, the strength of the liner plate is improved, and a permeation tank capable of sufficiently withstanding the ground pressure can be constructed.

<F> By using styrodren for the drainage plate,
It is possible to obtain a liner plate that is lightweight, easy to handle, and good for compression.

 Further, it also serves as a cushioning material.

<G> Since the sedimentation tank and the permeation tank are located vertically, the occupied area of the entire apparatus can be reduced.

[Brief description of the drawings]

 FIG. 1: Illustration of an embodiment of a permeation device FIG. 2: Illustration of a method of subsidence construction of an infiltration device FIG. 3: Illustration of a liner plate FIG. 4: Illustration of operation FIG. Illustration of

Claims (1)

(57) [Claims] 1. A method of constructing an underground infiltration apparatus for burying underground water to penetrate underground water into the ground, wherein an outer peripheral portion is formed by a perforated drainage plate, and an inner peripheral portion is formed by a perforated corrugated plate. A cylindrical body is constituted by an arc-shaped liner plate, and the ground near the lower part inside the cylindrical body is excavated, and the cylindrical body is connected to be lowered to a predetermined depth to form a permeation tank. A sedimentation tank having no water permeability, which is provided with a water collecting pipe for taking in water from the ground, and a water passage that communicates the interior of the sedimentation tank with the inside of the infiltration tank, closes the lower end and affixes a filter cloth. A method for constructing an underground infiltration device, comprising providing a pipe.