JPH0619665Y2 - Underground infiltration equipment - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to an underground infiltration device for infiltrating the rainwater into the ground without directly introducing it into the sewer pipe to minimize the outflow of rainwater to the outside of the area. It is a thing.

<Prior Art> Rainwater originally permeated underground, but as urbanization progressed and the surface of the ground was covered with concrete, asphalt, etc., the amount of rainwater permeating into the ground decreased.

As a result, problems such as an increase in outflow of rainwater to the sewers, water flowing to rivers in a short time immediately after rainfall, and a decrease in groundwater volume causing ground subsidence have occurred.

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

In this construction method, a device as shown in FIG. 6 is used.

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

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

<B> In the conventional underground infiltration device, when the cylinder a is buried in the ground, bentonite and earth retaining are used to excavate the ground.

However, when bentonite is used, bentonite flows into the gaps in the permeation layer of the surrounding ground, clogging the permeation surface, reducing the permeation amount of water, and even if washed, the permeation amount can be completely restored. It will be difficult.

Further, when soil retaining is used, the aggregate structure of soil on the permeation surface of the surrounding ground is destroyed, and the permeation amount of water also decreases.

<B> Since the structure is such that the PVC pipe b directly guides water from the water collecting chamber on the ground to the infiltration part c, the filtration of water is insufficient.

Therefore, it causes clogging of the permeation surface.

<Purpose of the present invention> The present invention was made in order to solve the above-mentioned problems. Underground infiltration that prevents clogging and destruction of the infiltration surface of the ground and allows water to permeate efficiently The purpose is to provide a device.

<Structure of the Invention> An embodiment of the invention will be described below with reference to the drawings.

<a> Settling tank (Fig. 1) In the settling tank 1, a cylindrical straight wall 12 is fixed to an upper surface of a floor plate 11,
Further, a slanted wall 13 having a diameter gradually reduced toward the upper part is fixed to the upper end of the straight wall 12.

The floor plate 11, the straight wall 12, and the sloping wall 13 are made of concrete or the like, and have a structure in which water does not leak to surrounding ground.

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

In addition, the settling tank 1 is provided with a water collecting pipe 15 which connects the above-ground water collecting section and the inside of the settling tank 1.

<B> Permeation tank (Fig. 1) In the permeation tank 2, the liner plate 21 is assembled 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 has crushed stones 27 in the upper layer and coarse sand 28 in the lower layer.
Is laid.

<C> Liner plate (FIGS. 1 and 2) As shown in FIG. 2, the liner plate 21 is a plywood plate in which a drainage plate 22 and a corrugated plate 23 are attached to each other, and is formed in an arc shape having a predetermined diameter on the corrugated plate 23 side. It is a bent one.

The drain 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 known styrodrene (manufacturer Mitsubishi Petrochemical Badishe Co., Ltd.) obtained by solidifying foamed polyethylene foam particles with a special adhesive is used.

This styro drain is lightweight, easy to handle, has a permeability coefficient similar to that of small gravel (k = 2.7 to 3.5 cm / sec), and is strong against compression.

Further, the water that has penetrated from one side of the styrodren has the property of being widely dispersed and evenly discharged when discharged from the other side.

Next, the corrugated plate 23 is used to reinforce the drainage plate 22, and a corrugated plate made of a steel plate or the like is used.

A drainage hole 24 is formed in the corrugated plate 23, and a connecting frame 26 having a connecting hole 25 is attached to the peripheral edge of the drainage hole 24.

When connecting the liner plates 21 to each other in a tubular shape,
A bolt 29 may be inserted into the connecting hole 25 and fastened with a nut.

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

The filtration pipe 3 is detachably attached to the floor plate 11 of the settling tank 1 in the vertical direction with a fixing band 31 or the like to connect the inside of the settling tank 1 and the inside of the permeation tank 2.

When mounting, it is desirable that the upper end of the filtration pipe 3 be raised by about 60 cm from the floor plate 11 and mounted.

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 outer surface of the pipe at the rising portion of the filtration pipe 3 on the floor plate 11, and the folded portion 33 is provided.
And

When clogging substances adhere to the filter cloth 32 and the water permeability decreases, the fixing band 31 may be removed, the filter pipe 3 may be removed, and the filter cloth 32 may be reattached.

<Construction method> Next, a construction method of the above-mentioned underground infiltration device will be described.

As the construction method, for example, the following two methods can be adopted.

<A> Reverse winding method (Figs. 1 and 4) First, the ground is excavated for one ring of the liner plate 21.

When excavating, be careful to protect the natural ground conditions as much as possible.

Next, a water-permeable sheet (not shown) is attached to the infiltration side of the natural ground to prevent the inflow of fine particles.

Next, install the liner plate 21 on the infiltration surface of the ground,
The liner plates 21 in the left-right direction are connected to each other to assemble one ring.

Next, the ground is excavated by one ring below the ring, the liner plate 21 is assembled in the same ring shape, and the upper and lower rings are connected.

At this time, since the upper ring does not drop due to friction with the natural ground, the lower ring can be assembled.

After assembling the liner plate 21 to a predetermined depth and constructing the infiltration tank 2 by the same method, below the ground floor of the ground at the lower end of the infiltration tank 2, sand 28 in the lower layer and crushed stones 27 in the upper layer.
To lay.

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

At the upper end of the uppermost ring, the filtration pipe 3 and the water collection pipe 15
The settling tank 1 equipped with the
Only the upper lid 14 is exposed to the ground.

The end of the aboveground portion of the water collection pipe 15 is connected to a water collection box or the like.

Although the above is the case of excavating the rock mass in one ring unit, the rock mass may be excavated in the liner plate unit.

<B> Settling construction method (Figs. 1 and 5) When the settlement method is adopted, first, 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 to the upper side, the ring is sunk by its own weight.

However, since the liner plate 21 is lightweight, it is difficult to sink due to its own weight.
Make it easy to sink by giving vibration.

At the time of subsidence, various known caisson subsidence methods can be adopted.

After sinking to a predetermined depth to construct the infiltration tank 2, sand 28 and crushed stone 27 are laid and the end of the aboveground portion of the water collecting pipe 15 is connected to a water collecting box or the like, as in the reverse winding method.

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

<B> Rainwater collected on the ground in the water collecting chamber collects water in the collecting pipe 15
Flow into the settling tank 1 via.

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

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

Further, the large clogging substance remains in the precipitation tank 1 by precipitation.

Furthermore, when the amount of rainfall increases, the filtration pipe 3
Since the water overflows from the settling tank 1 and flows out to the ground only by the inflow from the side surface, when the water level becomes high to some extent, the water is introduced from the upper open end of the filtration pipe 3.

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

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

Therefore, when the water in the infiltration tank 2 is discharged into the ground,
Dispersed widely and evenly.

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

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

<a> A permeation tank can be constructed while protecting the ground with a liner plate with excellent water diffusion.

Therefore, even if the burial depth increases, the infiltration tank can be installed while maintaining good infiltration performance of the ground.

<B> Generally, a filter material such as crushed stone is apt to be clogged with a lapse of time and its filtering function is deteriorated.

In this invention, the filtration pipe can be attached and detached at any time to clean,
Good filtration performance can be maintained semi-permanently.

<C> In a conventional permeation tank filled with crushed stone inside and outside the perforated tube, the perforated tube was not removed because the crushed stone collapses and the permeation tank collapses when the perforated tube is removed. .

On the other hand, in the present invention, since there is no collapsible member such as crushed stone in the infiltration tank, the filtration pipe can be easily attached and detached.

<D> Since there is no crushed stone in the infiltration tank, the water storage capacity of the infiltration tank increases by the amount of crushed stone.

This is suitable as a rainwater treatment facility in a land that has no direct discharge.

[Brief description of drawings]

 FIG. 1: Explanatory drawing of an embodiment of the device of the present invention FIG. 2: Explanatory drawing of liner plate FIG. 3: Explanatory drawing showing action FIG. 4: Explanatory drawing of reverse winding construction method FIG. 5: Subsidence construction method Fig. 6: Explanatory diagram of prior art

Claims (1)

[Scope of utility model registration request] 1. An underground infiltration device which is buried in the ground to infiltrate ground water into the ground, and a non-permeable settling tank equipped with a water collecting pipe for taking in the ground water, and a position below the settling tank. It consists of a permeable tank that allows water to penetrate into the ground, and a filtration pipe that projects upward from the bottom of the settling tank and guides the lower part to the permeable tank to connect the inner spaces of both tanks. An underground infiltration device, wherein a liner plate having excellent water diffusion properties is assembled into a tubular shape to form an infiltration tank, and a filtration pipe communicating between the two tanks is detachably configured.