JP2002004394A - Penetration type box culvert, penetration type sewer, and construction method for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce labor and costs in manufacturing by enabling the regulation of a designed flow rate in a pile and the quantity of penetration, allow the flow rate in the pipe to be secured in the case of a low water level in the pipe, and prevent the softening of the site ground and the differential settlement of a sewer by enabling time-lapse water absorption/drainage in accordance of variations in the flow rate in the pipe. SOLUTION: The penetration type box culvert 1 is provided with a box culvert body 2 and fitting side walls 10 and 15 formed in such a manner as to be able to be fitted into the fitting window 6 and divided into two upper and lower stages. Water/drain inlets 11, 16, and 17 are formed in the walls 10 and 15, and a flow regulating valve 12 is installed in the water/drain inlet 11 at the lowest level.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an infiltration type box culvert having a function of draining water flowing in a pipe and infiltrating the ground, and a function of absorbing groundwater in the ground into the pipe, and a method of constructing the infiltration sewer. It is about.

[0002]

2. Description of the Related Art When a large amount of rainwater flows into a box culvert due to a large amount of rainwater flowing into the box culvert, a part of the water flowing in the pipe penetrates into a ground outside the pipe from a rainwater penetration hole formed in a side wall of the box culvert. An infiltration type box culvert is known (for example, Japanese Utility Model Application Laid-Open No. 64-4).
2377). Also, as a material that allows a greater amount of rainwater to penetrate quickly, a required number of long holes for rainwater penetration and a required number of perforated tube insertion holes are formed in the side wall, and a long perforated tube is inserted into the perforated tube insertion hole. An attached osmotic culvert is also known (JP-A-8-184090).

[0003]

However, the above-mentioned permeation type culvert has the following problems.

In order to integrally mold a box culvert having a rainwater infiltration hole, a rainwater infiltration slot or a perforated pipe insertion hole (hereinafter referred to as a rainwater infiltration hole) with precast concrete, it is necessary to design, manufacture and mold a mold. It takes time and effort to remove the mold, and the cost increases. Also, rainwater infiltration holes and the like are formed with fixed shapes and dimensions at a fixed level (height) of the side wall, and the running water in the pipe is simply permeated into the ground from the rainwater infiltration holes and the like. The adjustment of the flow rate and the adjustment of the permeation amount are not considered. If it is attempted to change the level or shape of the rainwater infiltration hole or the like in various ways, it is impractical because a new mold must be designed and manufactured for each change.

[0005] Water can freely enter and exit through rainwater infiltration holes and the like, regardless of whether the water level is normal or when water is increased. Therefore, even when the water level in the pipe is low, if it is above the rainwater infiltration hole, etc., the water flowing in the pipe will always penetrate into the ground from the rainwater infiltration hole, etc. due to the head difference. A situation arises in which we cannot secure Also, a large amount of seepage water softens the local ground and causes uneven settlement of the sewer.

Accordingly, a first object of the present invention is to enable adjustment of a planned flow rate in a pipe and adjustment of a permeation amount, thereby reducing manufacturing labor and cost. A second object is to make it possible to secure a flow rate in the pipe when the water level in the pipe is low. A third object is to enable time-lagged suction / drainage corresponding to a change in the flow rate in the pipe, and to prevent softening of the ground at the site and uneven settlement of the sewer.

[0007]

In order to solve the above problems, the following osmotic box culverts (1) and (2)
(3) The infiltration sewers (4) and (5) and the construction method (6) were created.

(1) A box culvert body made of precast concrete having a fitting window penetrating through a side wall, and a water intake / drain port for allowing water to flow in and out of the fitting window. Infiltration box culverts with fitted side walls. (2) An infiltration box culvert in which suction and discharge ports for allowing water to flow in and out of at least the upper and lower two levels of the side wall are provided, and a flow control valve for securing a flow rate in the pipe is provided at the lowest level of the suction and drain ports. (3) A box culvert body made of precast concrete having a fitting window penetrating through the side wall, and a fitting sidewall formed so as to be fitted into the fitting window, and at least two levels above and below the fitting sidewall. An osmotic box culvert in which a suction / drain port for allowing water to enter / exit is formed, and a flow control valve is provided at the lowest level of the suction / drain port to ensure the flow rate in the pipe.

In the above (1) and (3), the following embodiments can be exemplified. The material and manufacturing method of the fitting side wall are not particularly limited, but are preferably made of precast concrete in view of strength and low cost. The suction / drain port may be a mode in which a hole serving as a suction / drain port is penetrated in the fitting side wall, or a mode in which a recess serving as a suction / drain port is formed in an outer peripheral edge of the fitting side wall. In the latter case, at the time of insertion, a suction hole and a drainage hole are formed by the recess and the inner peripheral edge of the fitting window facing the recess.

Although the fitting side wall may be formed in one step, it is preferable that the side wall is divided into at least two steps. Even in one stage, it is possible to adjust the planned pipe flow rate and the permeation amount by preparing fitting side walls with different levels and shapes and dimensions of the suction and drainage ports, and selecting and fitting them as appropriate. For example, since the intake and drainage ports can be formed in each stage, it is easy to increase the variation of the level and the shape and size of the intake and drainage ports.
In this case, it is possible to adopt a mode in which a recess serving as the suction / drain port is formed at the lower edge of the relatively upper fitting sidewall or the upper edge of the relatively lower fitting sidewall. In this case,
An inlet / outlet port is formed by the recess and the lower or upper edge of the fitting side wall facing the recess.

The shape of the suction / drain port formed by the recess is not particularly limited, and examples thereof include a horizontally long slit, a square hole, and a semi-round hole. In addition, the shape of the suction / drain port formed by the hole is not particularly limited, and examples thereof include a square hole, a round hole, and a semi-round hole.

In the above (2) and (3), the following modes can be exemplified. It is preferable that the flow control valve is a valve that closes the suction and drain port when the water level in the pipe is higher than the groundwater level in the ground, and opens the suction and drain port when the water level is low. In this case, the structure of the flow control valve is not particularly limited, but an example is a valve in which the suction / drain port is closed in close contact with the inner wall surface of the periphery of the suction / drain port, and the suction / drain port is opened apart from the inner wall surface.

(4) An osmotic sewer constructed by connecting a plurality of the osmotic box culverts of the above (1), (2) and (3) or each aspect. (5) The communication in which the infiltration type box culverts of the above (1), (2) and (3) or the respective modes are juxtaposed outside the side wall of the box culvert of the existing sewer and formed on the adjacent side wall of both box culverts. An infiltration sewer constructed by widening the existing sewer cross section by matching the holes and communicating.

In the above (4) and (5), it is preferable to form a drainage ground outside the side wall of the seepage type box culvert. The drainage ground is not particularly limited,
It is preferably formed using a granular material such as crushed stone, split rock, waste concrete waste, and the like, and more preferably formed using the granular material and a water purification material.

Further, it is preferable to dispose a suction prevention material having a flow resistance and a filter action at the suction / drainage port. In addition, it is preferable to lay foundation concrete immediately below the infiltration box culvert. Furthermore, it is preferable to lay the foundation concrete right under the infiltration box culvert or to the groove bottom of the site ground that protrudes directly under the box culvert.

(6) After carrying the box culvert body of (1) or (3) or each mode to the site, the fitting side wall is fitted into the fitting window to assemble into a permeation type box culvert. A method of constructing an infiltration sewer characterized by connecting a plurality of box culverts.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] FIGS. 1 to 9 show a seepage type sewer of a first embodiment. As shown in FIG. 2, the seepage type box culvert 1 used in the seepage type culvert includes a bottom plate 3, a pair of side walls 4, and a top plate 5, and a fitting window 6 is provided through the side wall 4. A precast concrete box culvert main body 2 and a precast concrete insertion side wall 10 formed so as to be insertable into the insertion window 6 and divided into two upper and lower stages (or three or more stages).
15 is provided. The fitting window 6 is formed as a large square hole that leaves the four sides of the side wall 4 in a frame shape.

In the lower portion of the lower fitting side wall 10, for example, three round holes serving as the lowest level suction / drain port 11 are formed so as to be arranged side by side, and the suction / drain port 11 is for securing a flow rate in the pipe. A flow control valve 12 is provided. Flow control valve 1
Reference numeral 2 denotes a flap-type valve whose upper end is attached to an inner wall surface of the periphery of the suction / drain opening 11 by a hinge (not shown). The suction / drain port 11 is closed in close contact with the inner wall surface, and when low, the suction / drain port 11 is opened apart from the inner wall surface.

At the lower edge and the upper edge of the upper fitting side wall 15, there are formed horizontally long recesses serving as a middle-level suction / drain port 16 and a top-level suction / drain port 17, respectively. That is,
When the fitting side walls 10, 15 are fitted into the fitting window 6,
A recess at the lower edge of the fitting side wall 15 and the fitting side wall 1 facing the recess.
The upper level 0 and the upper edge form a middle level suction / drain port 16, and the upper level level suction / drain port 17 is formed by the recess at the upper edge of the fitting side wall 15 and the inner peripheral edge of the fitting window 6 facing the recess. . Further, in this example, the mouth height and the opening area of the uppermost level suction / drain port 17 are set to be larger than those of the middle level suction / drain port 16.

As the infiltration box culvert 1, a modified example as shown in FIG. 3 or FIG. 4 can be used. In the first modification shown in FIG. 3, the lowermost level suction / drain port 11 and the middle level suction / drain port 1 are directly provided on the side wall 4 without employing the fitting window 6 and the fitting side walls 10 and 15.
6 and the uppermost level suction / drain port 17 are provided, and each level of the suction / drain port is, for example, three round holes.

The second modification shown in FIG. 4 is a modification of the bottom plate 3 in which the top surface is flat in the example of FIG. 2. FIG. 4A shows an example in which the top surface of the bottom plate 3 is formed in a circular arc shape with a low center. , (B) show that the upper surface of the bottom plate 3 has a low slope at the center and a groove 7 at the center.
In the example (c), a groove 7 is formed in the center of the upper surface of the bottom plate 3 and a hollow portion 8 (which may be filled with a foamed resin or the like) is formed in the bottom plate 3 having a thick wall on both sides. It is an example. Although mud and the like easily accumulate in the lower part or groove 7 at the center, there is an advantage that the sediment deposited in the lower part or groove 7 can be cleaned very easily.

Now, an infiltration sewer constructed using the infiltration box culvert 1 will be described together with a construction method (construction procedure). <Step 1> The local ground 20 is excavated in a groove shape in which the width of the groove bottom 23 is wider than the width of the box culvert 1,
Is an upwardly extending slope, and a suction prevention member 22 having a flow resistance and a filter action is laid on the inner surface 21 of the groove.
As the suction prevention member 22, for example, "Tafnel EX" (trade name, manufactured by Mitsui Chemicals, Inc.) can be used.

<Step 2> Crushed foundation 24, foundation concrete 25 and mortar 2
6 is laid in order. After the box culvert main body 2 is carried out of the groove at the site, the side walls 10, 1 are inserted into the insertion window 6.
5 is assembled into the infiltration box culvert 1. Since the joints of the fitting side walls 10 and 15 have an auxiliary water permeation function, it is not necessary to perform a special water stopping process (of course, they may be performed). The flow regulating valve 12 is attached to the fitting side wall 10 (at a factory or a site) before this assembling. The assembled osmotic box culvert 1 is set on the mortar 26.

<Step 3> Side wall 4 and fitting side wall 10,
15 suction and drain ports 11, 16,
A suction prevention member 27 (filter) having a flow resistance and a filter action is applied to and disposed around 17 and the peripheral portion thereof. As the suction prevention member 27, for example, the above-mentioned “tuffnel EX” can be used. A drainable ground 30 in which, for example, back crushed stones 28 and water purification materials 29 are alternately laid on both sides of the infiltration box culvert 1 on the foundation concrete 25.
To form As the water purification material 29, for example, "Bio Loop" (trade name) of Kureha Gosen Co., Ltd. can be used. A suction prevention member 31 is laid on the drainable ground 30. As the suction prevention member 31, for example, the above-mentioned “tuffnel EX” can be used.

<Step 4> The excavated soil 32 is backfilled on the infiltration type box culvert 1 and the suction-preventing material 31 to allow the water in the box culvert 1 to flow.

A description will be given of the mechanism of drainage / penetration into the ground and water absorption from the ground by the seepage type conduit constructed as described above. First, when the groundwater level in the drainable ground 30 is lower than the water level in the pipe of the infiltration type box culvert 1, and when the water level in the pipe changes, the water flowing in the pipes 11, 16, 17 from the pipes 31, 16, 17 to the ground 30, 20. The following shows the state of penetration into.

As shown in FIG. 5A, when the flow rate in the pipe is small and the water level in the pipe is low near the flow control valve 12, the water pressure due to the flow water in the pipe acting on the flow control valve 12 is small. 12 hits the inner wall surface but has low adhesion. Therefore, a part of the water flowing in the pipe is drained from the suction / drain port 11 and penetrates into the drainable ground 30, and then the local ground 2
Penetrates to zero.

As shown in FIG. 5 (b), the flow rate in the pipe is higher than the situation, and the water level in the pipe is at a middle level.
When approaching 6, the water pressure due to the flowing water in the pipe acting on the flow control valve 12 increases, and the flow control valve 12 increases the adhesion to the inner wall surface. Therefore, a small amount of water flowing in the pipe leaks out from the suction / drain port 11 and penetrates into the grounds 30 and 20, but most of the flow rate in the pipe is secured in the pipe.

As shown in FIG. 6A, the flow rate in the pipe is larger than the situation, and the water level in the pipe 1 is at a middle level.
When the flow reaches or exceeds 6, the action of ensuring the flow rate in the pipe by the flow control valve 12 is the same as the situation, but due to the head difference between the pipe water level and the groundwater level, the water flowing in the pipe is drained from the medium-level suction and drain port 16 and drained. The groundwater level rises by infiltrating into the ground 30, and then infiltrates into the local ground 20. That is, it is possible to permeate the ground 30, 20 while the flow rate in the pipe is secured to some extent. At this time, since the suction prevention member 27 disposed at the suction / drainage port 16 has a flow resistance, the flowing water in the pipe gradually permeates into the ground 30, 20. In addition, since the suction prevention member 27 has a filter function, the discharge of dust and dirt contained in the flowing water in the pipe is stopped, and the drainage ground 30 is prevented from being clogged.

As shown in FIG. 6 (b), when the flow rate in the pipe further increases than the situation and the water level in the pipe reaches or exceeds the highest level of the suction / drain port 17, the action of securing the flow rate in the pipe by the flow control valve 12 is as follows. In the same manner as described above, the flowing water in the pipe is drained also from the suction / drain port 17 at the highest level and permeates the drainage grounds 30 and 20. In other words, when the inside of the pipe is filled with flowing water, the flowing water in the pipe is efficiently drained from the suction and drain ports 16 and 17 and permeates the ground 30 and 20. The function of the suction prevention member 27 is the same as that of the situation.

Next, when the water level in the pipe of the infiltration type box culvert 1 is lower than the groundwater level in the drainable ground 30, and when the water level in the pipe changes, the suction and drainage port of the groundwater in the ground 30 is changed. The status of water absorption from 11, 16, 17 into the pipe is shown in the following.

As shown in FIG. 7A, the amount of drainage supplied to the pipe (rainfall) decreases, the drainage in the pipe becomes faster than in the drainable ground 30, and the flow rate in the pipe decreases as compared with the situation. When the water level in the pipe is lower than the groundwater level of the drainage ground 30, the groundwater in the ground 30 is absorbed into the pipe from the suction / drain opening 17 at the highest level due to the head difference between the water level in the pipe and the groundwater level. At this time, the suction-preventing member 27 disposed at the suction / drain port 17
Has a flow resistance, so the groundwater has a time difference (time delay)
With this, water is gradually absorbed into the pipe.

As shown in FIG. 7 (b), the flow rate in the pipe is lower than the situation, and the water level in the pipe is at the middle level.
When it is lower than 6, the groundwater in the ground 30 is absorbed into the pipe from the suction / drain port 16 at the middle level. The function of the suction prevention member 27 is the same as that of the situation.

As shown in FIG. 8A, when the flow rate in the pipe is further reduced than in the situation and the water level in the pipe is lower than the suction / drain port 11 at the lowest level, the groundwater in the ground 30 opens the flow control valve 12. Water is sucked into the pipe from the suction / drain port 11 at the lowest level. Suction prevention material 2
The operation of 7 is similar to the situation.

As shown in FIG. 8B, when the flow rate in the pipe increases again and the water level in the pipe increases, water absorption into the pipe stops, and the situation becomes the same as the situation.

According to the osmotic pipe constructed as described above, the following operation and effect can be obtained.

(1) Improvement of the original function and effect of the infiltration sewer For the problem that the flow rate in the sewer increases and the overflow frequently occurs, the surrounding ground is made drainable ground 30 without increasing the diameter of the sewer,
This can be dealt with by efficiently infiltrating the flowing water in the pipe into the drainage ground 30. Also, groundwater drop
Drainage ground 3
It responds by infiltrating the local ground 20 through 0,
Improve the water retention / recharge function of the local ground 20.

(2) Adjustment of the planned pipe flow rate and the adjustment of the amount of water flowing in the pipe into the ground are possible. Fitting side walls 10 and 15 provided with suction and drain ports 11, 16 and 17.
Is precast separately from the box culvert main body 2 so as to be fitted into the fitting window 6, so that the shapes of the fitting side walls 10, 15 and the levels (heights) of the water inlet / outlet ports 11, 16, 17 are provided. And the shape and dimensions can be arbitrarily determined.
Then, only by forming the fitting side walls 10 and 15 in which the levels and the shapes and dimensions of the suction and drain ports 11, 16 and 17 are adjusted, it is possible to adjust the planned pipe flow rate and the amount of permeation into the ground 30, 20.

(3) Possible to reduce labor and cost in manufacturing Fitting side walls 10 and 15 provided with suction and drainage ports 11, 16 and 17
Is precast separately from the box culvert main body 2, so that the production labor and cost can be reduced as compared with the case where the box culvert is integrally formed. In particular, when the inlet / outlet port is a hole, it takes a lot of time to integrally form the box culvert, so the present invention is effective.

(4) It is possible to secure the flow rate in the pipe when the water level in the pipe is low. By providing the flow control valve 12 in the suction / drainage port 11 at the lowest level, as described in the above-mentioned conditions, when the water level in the pipe is low, In this case, it is possible to secure the flow rate in the pipe that should be flown (in the pipe).

(5) Time-difference suction / drainage corresponding to the change in the flow rate in the pipe is possible. Flow control valve 12 is provided at suction / drain port 11 at the lowest level, and suction prevention material 27 is arranged at suction / drain ports 11, 16 and 17. As described in the above situation ~
Time difference suction and drainage corresponding to the change in the pipe flow rate becomes possible.
As a result, rapid softening of the local ground 20 can be prevented.

(6) Prevention of Uneven Settlement of the Ground and Sewer The uneven settlement of the local ground 20 and the seepage sewer can be prevented by the time difference drainage of the above (5). In addition, laying the foundation concrete 25 directly under the seepage type box culvert 1 also helps prevent the above-mentioned uneven settlement. Furthermore, the uneven concrete settlement can be further prevented by laying the foundation concrete 25 normally laid only directly under the box culvert 1 to the groove bottom 23 protruding just below the box culvert 1.

(7) Addition of Water Purification Function Since the drainage ground 30 uses not only the back crushed stone 28 having the water purification effect between gravel but also a water purification material, the drainage ground 30 has its water purification function (this example). In such a case, purification of water quality can be expected by a purification mechanism by biochemical removal of "bioloop". In addition, as a backing material, not only crushed stones such as single-grain crushed stones and split stones but also waste concrete gala as a construction by-product can be used. When using waste concrete waste, it is preferable to use a neutralized one to some extent, or to add an alkali neutralizer if not.

By the way, when there is a vertical gradient as shown in FIG. 9, and when no treatment is performed as shown in FIG. 9A, the relative levels of the intake and drain ports 11, 16, and 17 with respect to the groundwater level are excessively shifted. Therefore, the water flowing in the pipe is
It cannot penetrate into the ground efficiently from 6,17. Therefore,
As shown in (b), the impermeable sheet 33 that can arrange the groundwater level stepwise is installed at, for example, about 20 m intervals,
(C) As shown in FIG.
By adjusting the shape and size of the, efficient penetration can be made possible.

[Second Embodiment] FIG. 10 shows a seepage type sewer according to a second embodiment. When the site ground 20 is excavated in a groove shape, the infiltration type sewer is driven into a vertical surface by driving a sheet pile 35 instead of making the inner side surface of the groove an upwardly expanding slope, and the gap between the sheet pile 35 and the drainage ground 30 is formed. Waterproof sheet 36 between
Is different from the first embodiment in that This embodiment is suitable when there is a restriction on a land such as an urban area.

Third Embodiment Next, FIG. 11 shows a seepage type sewer of a third embodiment. In the seepage type culvert, the seepage type box culvert 1 of the first embodiment is connected to the outside of both (or one) side walls of the box culvert 40 of the existing sewer and is juxtaposed.
The cross section of the existing culvert is enlarged by matching and communicating the communication holes (core holes) 41 formed in the adjacent side walls. According to the present embodiment, for example, an existing sewer cross section such as an urban area where a sewer cross section (cross-section water passage cross section) becomes insufficient can be arbitrarily widened.

It should be noted that the present invention is not limited to the above-described embodiments, and may be embodied with appropriate modifications without departing from the spirit of the present invention.

[0048]

According to the first aspect of the present invention, it is possible to adjust the flow rate in the planned pipe and the amount of permeation, thereby reducing the manufacturing labor and cost. The invention according to claim 2 makes it possible to secure the flow rate in the pipe when the water level in the pipe should be low when the water level in the pipe is low. I do. The invention according to claim 3 has both of these effects. The inventions according to claims 4 to 20 have both these effects and the effects described above.

[Brief description of the drawings]

FIG. 1 is a sectional view of a seepage type sewer according to a first embodiment of the present invention.

FIG. 2 is a perspective view of a seepage type box culvert used for the seepage type sewer.

FIG. 3 is a perspective view of a first modification of the seepage type box culvert.

FIG. 4 is a sectional view of a second modification of the seepage type box culvert.

FIG. 5 is a sectional view showing a drainage state by the seepage type sewer.

FIG. 6 is a sectional view showing a continuation of a drainage state by the seepage type sewer.

FIG. 7 is a sectional view showing a state of water absorption by the seepage type sewer.

FIG. 8 is a sectional view showing a continuation of the state of water absorption by the seepage type sewer.

FIG. 9 is a side view when the seepage type sewer has a vertical gradient.

FIG. 10 is a sectional view of a seepage type sewer according to a second embodiment of the present invention.

FIG. 11 is a sectional view of a seepage type sewer according to a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Penetration type box culvert 2 Box culvert main body 3 Bottom plate 4 Side wall 5 Top plate 6 Fitting window 10 Fitting side wall 11 Bottom level suction and drainage port 12 Flow control valve 15 Fitting side wall 16 Medium level suction and drainage port 17 Top level Suction and drainage port 20 Local ground 25 Foundation concrete 27 Suction prevention material 28 Back crushed stone 29 Water purification material 30 Drainable ground 32 Excavated soil 40 Box culvert of existing sewer 41 Communication hole

Claims (20)

[Claims] 1. A box culvert body made of precast concrete having a fitting window penetrating through a side wall, and a water intake / drain port for allowing water to flow in and out of the fitting window. Infiltration box culverts with fitted side walls. 2. An infiltration box culvert in which suction and discharge ports for allowing water to flow in and out of at least upper and lower two levels of a side wall are provided, and a flow control valve for securing a flow rate in a pipe is provided at the lowest level of suction and discharge ports. 3. A box culvert body made of precast concrete having a fitting window penetrating through a side wall, and a fitting sidewall formed so as to be fitted into the fitting window. An osmotic box culvert in which suction and discharge ports for allowing water to flow in and out of at least two upper and lower levels are provided, and a flow control valve for securing a flow rate in the pipe is provided at the lowest level of suction and discharge ports. 4. The infiltration box culvert according to claim 1, wherein the fitting side wall is made of precast concrete. 5. The seepage type box culvert according to claim 1, wherein a hole serving as the suction / drain port is provided through the fitting side wall. 6. The osmotic box culvert according to claim 1, wherein a recess serving as the suction / drain port is formed in an outer peripheral edge of the fitting side wall. 7. The infiltration box culvert according to claim 1, wherein said fitting side wall is formed by dividing it into at least two upper and lower stages. 8. The infiltration box culvert according to claim 7, wherein a recess serving as the suction / drain port is formed at a lower edge of the relatively upper fitting sidewall or an upper edge of the relatively lower fitting sidewall. 9. The osmotic box culvert according to claim 6, wherein the suction / drain port formed by the recess has a horizontally elongated slit shape. 10. The osmosis type valve according to claim 2, wherein the flow control valve is a valve that closes the suction / drain port when the water level in the pipe is higher than the groundwater level in the ground, and opens the suction / drain port when the water level is low. Box culvert. 11. The osmotic box culvert according to claim 10, wherein the flow control valve is a valve that closes the suction / drain port in close contact with the inner wall surface of the peripheral edge of the suction / drain port, and opens the suction / drain port away from the inner wall surface. . 12. An osmotic pipe constructed by connecting a plurality of osmotic box culverts according to any one of claims 1 to 11. 13. The infiltration box culvert according to any one of claims 1 to 11, which is juxtaposed outside a side wall of a box culvert of an existing sewer, and formed on an adjacent side wall of both box culverts. An infiltration sewer constructed by widening the existing sewer cross section by matching the communication holes and communicating. 14. The seepage type culvert according to claim 12, wherein a drainage ground is formed outside a side wall of the seepage type box culvert. 15. The infiltration sewer according to claim 14, wherein the drainage ground is formed by using a granular material such as crushed stone, split rock, waste concrete waste and the like. 16. The seepage type sewer according to claim 15, wherein the drainage ground is formed using the granular material and a water purification material. 17. A suction prevention member having a flow resistance and a filter action is disposed at the suction / drain port.
The seepage type sewer according to any one of the above. 18. The seepage type culvert according to claim 12, wherein foundation concrete is laid immediately below the seepage type box culvert. 19. The seepage type culvert according to claim 12, wherein foundation concrete is laid immediately below the seepage type box culvert or to a groove bottom of the site ground protruding immediately below the seepage type box culvert. 20. After the box culvert main body according to claim 1, 3, 4, 5, 6, 7, 8 or 9 is carried into the site, a fitting side wall is fitted into the fitting window, and a permeation box is provided. A method of constructing a seepage type sewer, comprising forming a culvert and connecting a plurality of the seepage type box culverts.