JP2016044478A - Underpass structure of road - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an underpass structure for a road that may replace an existing underpass part of a road with an underpass part, minimizing a traffic restriction period and making the underpass part difficult to be flooded or submerged and easy to maintain.SOLUTION: An underpass part UP has a vehicle traveling part 1 and non-vehicle traveling parts 2a, 2b, 2c lined up adjacent to each other in a width direction, and a surface layer of a flat part 23 of the non-vehicle traveling parts 2a, 2b, 2c and a surface layer of an inclined part 24 continuing from the flat part 23 are a permeable layer 3 made of a porous concrete into which rainwater that flows into the underpass part UP permeates.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an underpass structure of a road.

In recent years, the frequency of occurrence of guerrilla heavy rain in which a large amount of rain of 100 mm or more per hour falls in a narrow range such as 10 km square is increasing.
On the other hand, in Japan, most roads are asphalt pavement or concrete pavement, so rainwater hardly penetrates directly into the ground from the road surface and flows into the side gutters along the road. The water is drained to a river or the like through a drainage path connected to the gutter.

  Therefore, when the above guerrilla heavy rain occurs, rainwater exceeding the drainage capacity that falls on the road and its surroundings flows into the ditch at a stretch and overflows from the ditch, or the river water flows backward from the ditch due to the increase in the downstream river. Because rainwater flows vigorously on the road surface, the road may be submerged or flooded into surrounding houses due to the fact that leaves and garbage are collected at the entrance of the road gutter, etc. and are not drained into the gutter. The frequency of video flooding and housing flooding is increasing using public media such as TV and newspapers and social networking services (SNS).

Furthermore, the road may be provided with a three-dimensional intersection called an underpass portion provided so as to dive under other roads or railroads. Since the road surface is at a lower position than the general part, rainwater that falls on the general road part near the underpass part tends to flow.
Therefore, some underpass units are provided with a pumping facility for discharging the rainwater that has flowed out of the road, but even in the underpass unit equipped with a drainage pump, fallen leaves and garbage are drained. The underpass may be submerged by closing the drainage drain lid provided with the pump, or not being able to demonstrate sufficient drainage capacity due to insufficient maintenance of the drainage pump.

By the way, it is said that there are more than 3000 underpass parts across the country that are likely to be flooded or submerged due to the inflow of rainwater during heavy rain.
The underpass section is equipped with warning means such as an electric bulletin board that issues a warning so that a car or the like enters the flooded area and stops in the underpass section. There may be cases where the response is not in time during heavy rain.

  On the other hand, a U-shaped groove is provided in the deepest part of the underpass portion so as to cross the road, and rainwater flowing into the underpass portion is collected in this U-shaped groove, and rainwater flowing into the U-shaped groove is collected into the U-shaped groove. There has been proposed a drainage structure that prevents the flooding of the road inside the underpass part and the submersion of the underpass part from flowing into a rainwater storage and penetration tank buried in the vicinity (Patent Document 1).

JP 2012-46916

  However, when this drainage structure is employed in an existing underpass section, the road surface of the underpass section must be deeply dug in order to install the rainwater storage and penetration tank, resulting in a large construction.

Moreover, since the underpass section is overlying a railroad or another road and it is difficult to use a large heavy machine, the underpass section must be constructed with the underpass section closed for a long period of time.
In the case of the above drainage structure, rainwater flows into the rainwater storage and penetration tank from a hole provided in a part of the U-shaped groove, and maintenance is inadequate and mud etc. is blocking the hole. There is a possibility that rainwater may not be sufficiently drained into the rainwater storage and penetration tank due to clogging of the holes by fallen leaves and dust that have flowed into the groove, and the same problem as in the past remains.

  In view of the above circumstances, the present invention provides an underpass portion of a road that can be changed to an underpass portion that is easy to maintain, with an underpass portion of an existing road shortened as much as possible to prevent flooding and submergence. Its purpose is to provide a structure.

  In order to achieve the above object, the road underpass portion structure according to the present invention (hereinafter referred to as “the underpass portion structure of the present invention”) includes an underpass portion, an automobile traveling portion, and an automobile non-traveling portion. Are adjacent to each other in the width direction, and at least the deepest flat portion of the underpass portion of the automobile and the surface layer of a part of the inclined portion connected to the flat portion flow into the underpass portion of the non-travel portion of the automobile. It is characterized in that it is a water permeable layer made of at least porous concrete through which rainwater penetrates.

The underpass portion structure of the present invention is suitable not only for constructing a new road, but also for modifying the conventional underpass portion of a road to a structure that is difficult to flood.
It is preferable to make the permeable layer thicker, considering that it is possible to temporarily store a larger amount of rainwater, but if it is thicker, it is necessary to dig deeper, and the construction period is longer and costs increase. Is 30 cm to 70 cm (preferably 50 to 60 cm).
By the way, in the case of an underpass part with a width of 10 m, the deepest flat part length of 10 m, and the inclined part on both sides of the flat part of 25 m, when 100 mm of guerrilla heavy rain falls for 30 minutes per hour, the deepest part of the underpass part However, it is expected that rainwater will flow in an amount of approximately 167 mm, but if the entire road surface of the underpass is made of porous concrete with a porosity of 30%, if the construction thickness is about 300 mm, it will continue for 1 hour. Even in the case of rain, it is calculated that rainwater can be almost absorbed (stored internally).

In addition, it is preferable that the motor vehicle travel part uses the surface layer part as general pavement.
The general pavement refers to normal asphalt pavement and concrete pavement in which a porous concrete layer such as the water permeable layer of the present invention is not exposed on the surface layer portion.

Moreover, although the underpass part structure of this invention of this invention is not specifically limited, It is preferable to provide the drainage pump which drains the rainwater which flowed into the water-permeable layer.
Although the said drainage pump is not specifically limited, It is preferable to be installed in the permeable drainage basin which has a lid | cover made from porous concrete.

The underpass part structure of the present invention is such that the deepest automobile traveling part of the underpass part has a communication layer made of porous concrete communicating with the water permeable layer of the automobile non-traveling part, and the perforated pipe is a water permeable layer. It is preferable to have a structure embedded in the communication layer so as to straddle.
In other words, by providing a porous concrete layer at the deepest part of the vehicle running part of the underpass part, rainwater penetrates not only into the water permeable layer but also into the porous concrete layer of the automobile running part, thereby increasing the temporary water storage amount. It is possible to make it easier to prevent flooding of the underpass part.
In addition, by embedding the perforated pipe, the porosity of the water permeable layer can be further increased as compared with the porous concrete layer alone.
In addition, when a drainage pump is provided, if a porous concrete layer is provided continuously to the permeable layer as described above, it is not necessary to provide a drainage pump for each of the plurality of permeable layers, and equipment costs and maintenance costs can be reduced. .

The perforated pipe is not particularly limited as long as it has a through-hole through which water permeated into the water-permeable layer can pass and can withstand the load applied from the surroundings during use, but is made of a synthetic resin such as vinyl chloride resin or polyethylene. Examples thereof include a perforated pipe, a perforated pipe made of a composite material such as FRP, a perforated steel pipe, and a perforated fume pipe.
The number of the through holes is not particularly limited as long as the strength that the peripheral wall is not damaged by the load applied from the surroundings can be secured, but it is preferable to provide as many as possible in consideration of the permeability of rainwater from the water permeable layer side into the pipe.

In other words, the lid of porous concrete is finer than the grating lid, etc., so fallen leaves, dust, fine earth and sand etc. are difficult to enter the drainage basin, and the drainage pump suction port can be prevented from clogging. Maintenance management becomes easier. In addition, an inexpensive and simple drainage pump can be used without using an expensive drainage pump of a type that takes into account clogging with dust or the like, and the cost can be reduced.
In addition, in the structure where the perforated pipe is embedded as described above, the drainage pipe is not provided, and the pipe connected to the suction port of the drainage pump or the suction port is connected to the end of the perforated pipe and enters the perforated pipe. Rain water or the like may be drained directly by a drain pump.

Further, the underpass structure of the present invention of the present invention may be configured such that the porous concrete portion of the water-permeable layer is formed of porous concrete having an upper layer made of finer aggregate than the lower layer and having a smaller void diameter. preferable.
That is, if fine aggregate is used, the void diameter can be reduced even with the same porosity, and fine mud or the like is easily filtered at a portion where the void diameter is small. On the other hand, the lower layer can have a structure with a large gap diameter and excellent water permeability and easy drainage.

The fine aggregate used in the upper layer is not particularly limited, but No. 8 crushed stone (1.2 to 2.5 mm), No. 7 crushed stone (2.5 to 5 mm), No. 6 crushed stone (5 to 13 mm), These mixtures are mentioned.
The coarse aggregate used in the lower layer is not particularly limited, and examples include No. 5 crushed stone (13 to 20 mm), No. 6 crushed stone (5 to 13 mm), and mixtures thereof.

  Also, when the water-permeable layer is made of porous concrete only, the above structure can be used. If the upper layer is clogged with mud that flows in along with rainwater, it can be washed by spraying high-pressure washing water on the washing surface, or by vacuum washing. It is possible to easily eliminate clogging.

In the underpass part structure of the present invention, the porous concrete constituting the water permeable layer and the porous concrete constituting the porous concrete layer have a porosity of 20% to 35% (preferably 25% to 35%). It is preferable to do.
That is, if the porosity is less than 20%, it takes too much time for water to pass, and the effect of preventing flooding of the underpass portion may be insufficient. Manufacture, construction and management are likely to be difficult.

The porous concrete constituting the water permeable layer and the porous concrete constituting the porous concrete layer preferably have a continuous porosity of 20% or more and a water permeability coefficient of 1 to 10 cm / s.
If the permeability coefficient is less than 1 cm / s, the infiltration is slow, and there is a possibility that the permeable layer cannot sufficiently exert the effect of preventing flooding.

The above porosity and continuous porosity are the volume pressure method (The Architectural Institute of Japan, Vol.75, No.650, p1043-1050, July 2008), JCI (Concrete Engineering Association) It is measured using the volume method described in (Porosity Concrete Porosity Test Method (Draft)).
The permeability coefficient is measured using the permeability test method described in the above-mentioned JCI standard draft (Porosity concrete permeability test method (draft)).

Moreover, the water cement ratio of raw porous concrete is not particularly limited, but is preferably 30 to 45%.
In addition, in raw porous concrete, an admixture, an AE water reducing agent, etc. can be mix | blended as needed other than an aggregate, cement, and water.

In addition, the water-permeable layer of the underpass structure according to the present invention protects the porous concrete layer having water permeability to such an extent that the water-permeable layer does not hinder the water permeability to the porous concrete as well as the case where the water-permeable layer is formed only from the porous concrete. A laminated structure including a protective layer may be used.
As a water-permeable protective layer, an interlocking block, resin mortar, etc. are mentioned, for example.

  In the present invention, the automobile non-traveling part means a part where the automobile does not normally travel, and includes a part where the automobile may travel in an emergency, for example, a median strip, roadside belt, sidewalk, bicycle path Is mentioned.

  As described above, the underpass portion structure of the present invention according to the present invention includes an underpass portion that includes an automobile running portion and an automobile non-running portion adjacent to each other in the width direction. The flat part of the deepest part of the pass part and the surface layer of a part of the inclined part connected to this flat part is a water permeable layer made of at least porous concrete through which rainwater that has flowed into the underpass part of the non-traveling part of the automobile permeates. The rainwater that flows into the underpass and reaches the permeable layer immediately penetrates into the permeable layer. Therefore, even if rainwater that exceeds the drainage capacity of the drainage mechanism installed in the underpass section flows into the underpass section, flooding of the underpass section should be prevented against heavy rain that has a short precipitation time, such as guerrilla heavy rain. Can do.

Moreover, even when the existing underpass portion is changed to the above-described underpass portion structure of the present invention, it is not necessary to excavate the road surface of the existing automobile traveling portion deeply, and the road stop period of the automobile traveling road can be shortened as much as possible. it can.
In other words, at least the porous concrete part of the water permeable part excavates the existing non-running part of the automobile by the thickness of the water permeable layer, and the raw concrete that becomes the porous concrete is poured into the excavated part, and it is only rolled from above as needed. The workability that can be formed in is good and can be constructed in a short time. Moreover, porous concrete has a large void ratio, and a large amount of rainwater can be stored in the void portion. Therefore, it is not necessary to dig deeply, and even in an underpass portion having a low ceiling height, heavy machinery such as a small backhoe is used. Can be excavated sufficiently. Therefore, the road closure period can be shortened as much as possible.

  Moreover, since the water permeable layer is provided in at least a part of the deepest part of the underpass part and the inclined part connected to the deepest part, it is possible to maintain a state in which a part of the water permeable layer is always exposed. That is, the rainwater that has flowed into the underpass without penetrating the upper part of the permeable layer completely with fallen leaves and dust penetrates into the permeable layer through the part of the permeable layer that is not covered with fallen leaves and trash. It flows sideways inside and spreads smoothly throughout the permeable layer, and even if it is partially clogged, the underpass will not be submerged and rainwater will penetrate smoothly.

BRIEF DESCRIPTION OF THE DRAWINGS It is 1st Embodiment of the underpass part structure of this invention, Comprising: It is the schematic explanatory drawing which looked at the underpass part and the road general part of the vicinity from the upper direction. It is a cross-sectional view of the underpass part of FIG. It is XX sectional drawing of FIG. It is sectional drawing of the drainage sewer of the underpass part of FIG. It is 2nd Embodiment of the underpass part structure of this invention, Comprising: It is the schematic explanatory drawing which looked at the underpass part and the road general part of the vicinity from the upper direction. It is 3rd Embodiment of the underpass part structure of this invention, Comprising: It is the schematic explanatory drawing which looked at the underpass part and the road general part of the vicinity from the upper direction. It is a cross-sectional view of the underpass part of FIG. It is 3rd Embodiment of the underpass part structure of this invention, Comprising: It is a cross-sectional view of the underpass part.

Hereinafter, the present invention will be described in detail with reference to the drawings showing embodiments thereof.
1 to 4 show an embodiment of the underpass structure of the present invention according to the present invention.

As shown in FIG. 1, the road A includes an underpass portion UP that intersects under the railroad R. In FIG. 1, NR is a road general part.
As shown in FIG. 1 and FIG. 2, the underpass unit UP is a two-lane automobile traveling unit (including a roadway portion 1 and a center that is not a vehicle traveling unit between the vehicle traveling unit 1 and the vehicle traveling unit 1. It has a separation band 2c and has sidewalks 2a and 2b which are non-traveling parts of the automobile on both sides in the width direction.

As shown in FIGS. 1 to 3, the median strip 2 c and the sidewalks 2 a and 2 b include a water permeable layer 3 in the surface layer portion over the entire length of the flat portion 23 and the inclined portion 24 of the underpass portion UP.
The water permeable layer 3 is formed of porous concrete having a porosity of 25 to 35%, a continuous porosity of 20% or more, and a water permeability coefficient of 1 to 10 cm / s.

The vehicle traveling unit 1 includes a water-permeable layer 11a in a flat portion 11 that is the deepest portion of the underpass portion UP.
The water-permeable layer 11 a is formed of porous concrete similar to the water-permeable layer 3, and is provided so as to be continuous with each water-permeable layer 3.
The surface of the water-permeable layer 11a is provided with asphalt general pavement 11b.

Furthermore, a plurality (four in this embodiment) of perforated pipes 5 are embedded in the water passage layer 11a in parallel.
The perforated pipe 5 penetrates the water-permeable layer 11a and the water-permeable layer 3 of the central separation zone, and is provided so that both ends thereof face the water-permeable layer 3 of the sidewalks 2a and 2b.

Further, the water permeable layer 3 of one sidewalk 2a has a drainage basin 22 formed as if a part of the sidewalk main body 21 is dug deeply at a position facing one perforated pipe 5 as shown in FIG. It has.
The drainage basin 22 accommodates a submersible pump type drainage pump P.

The upper part of the drainage basin 22 is closed with a porous concrete lid 4, and the drainage pump P is inspected by opening the lid 4.
Moreover, although not shown in figure in the water permeable layer 3 in which the drainage pump P was provided, the drainage piping and the electric wire pipe are embed | buried.

One end of the drainage pipe is connected to the discharge port of the drainage pump P in the drainage basin 22, and the other end faces the drainage path.
In addition, the above-mentioned electric conduit is configured to pass a cable for supplying electricity to a drainage pump P from a control box (not shown) provided outside the underpass portion UP, or a signal line connected to a level sensor or the like. ing.

Below, an example of the construction method of this underpass part UP is demonstrated in the order of the process.
(1) Excavate the sidewalk portion and the median strip portion of the underpass portion UP of the road A to the same depth as the thickness of the permeable layer 3 to be obtained by using a backhoe or an excavator or slightly deeper than that.
(2) Excavate only the flat part 11 of the vehicle traveling part 1 of the existing underpass part UP.
(3) A road bed and a roadbed (not shown) are formed on the bottom of the excavation part as necessary.
(4) Build a drainage drainage frame on the excavation part of one sidewalk.
(5) The drainage pipe is disposed in the excavation part so that one end thereof communicates with the drainage path outside the underpass part UP and the other end faces the mold part of the drainage basin 22.
(6) Excavating the conduit so that one end of the conduit can be connected to the control box outside the underpass portion UP or connected to the control box, and the other end faces the mold part of the drainage basin 22 It is arranged in the part.
(7) The perforated pipe 5 is installed in the excavation part in parallel in the horizontal direction so that one end faces the excavation part of one sidewalk and the other end faces the excavation part of the other sidewalk.
In carrying out the above steps (5) to (7), raw porous concrete may be poured into the excavation part up to a thickness that receives the lower ends of the drainage pipe, the electric wire pipe, and the perforated pipe.
(8) Pour raw porous concrete into the excavated part, embed the perforated pipe 5, drainage pipe, and electric pipe, and if necessary, compact it with a special vibration plate or rubber-wrapped tandem roller, and then cure and harden it. Thus, the water-permeable layer 3 and the water-permeable layer 11a are formed.
(9) Remove the form of the drainage basin 22, install the drainage pump P in the drainage basin 22, and connect the discharge port of the drainage pump P to the drainage pipe.
(10) The electric wire passed from the control box side through the electric conduit is connected to the drainage pump P. Further, a communication line connected to the control device of the control box is connected to a level sensor or the like as necessary.
(11) A general pavement 11b such as a normal asphalt pavement is applied on the water flow layer 11a.
(12) A lid formed of the same porous concrete as the water permeable layer 3 is attached to the upper portion of the drainage basin 22.

In the underpass part UP, the surface layer of the sidewalks 2a and 2b and the central separation zone 2c is a permeable layer 3, so that rainwater or the like flowing into the underpass part UP penetrates into the permeable layer 3. Go.
Further, since each water permeable layer 3 communicates with the water permeable layer 11 a, rainwater that has permeated the water permeable layer 3 penetrates the water permeable layer 11 a and also passes through the through holes 51 of the perforated pipe 5. Into the perforated pipe 5.

Then, the rainwater that has penetrated into the permeable layer 3 of one sidewalk 2 a flows into the drainage basin 22.
When rainwater that has flowed into the drainage basin 22 accumulates in the drainage basin 22 to a certain level, it is detected by a sensor (not shown) that rainwater has accumulated, and the drainage pump P is activated to enter the drainage path via the drainage pipe. Drained.

  Therefore, if the underpass portion UP is used, the amount of rainwater or the like flowing into the underpass portion UP exceeds the drainage capacity of the drainage pump P, and the gap between the water passage layer 11a and the perforated pipe 5 is completely filled. At the same time, unless the level of rainwater that has permeated into the water permeable layer 3 becomes higher than the deepest road surface of the underpass portion UP, the automobile traveling portion 1 is not almost flooded.

Further, the water permeable layer 3 and the water permeable layer 11a excavate the road surface of the existing underpass part of the sidewalk, the median strip and the flat part of the automobile traveling part to a depth of about several tens of centimeters to 1 meter, Since it can be formed almost by pouring concrete, it is not limited to the ceiling height of the underpass part, and can be constructed in a short period of time. That is, even if the ceiling height of the underpass portion is low, excavation work can be easily performed using a small backhoe or the like, and raw porous concrete may be poured from the mixer truck.
Since construction can be completed in a short time, the road closure period can be shortened. In addition, the placement of the guider on the detour can be completed in a short period, and the cost can be reduced.

Further, since the water permeable layer 3 and the lid 4 serve as a filter for fallen leaves, dust, mud, etc., it is possible to prevent fallen leaves, dust, mud, etc. from entering the drainage basin 22.
Therefore, the drainage pump P can be a simple type that does not include a filter device or the like, and the equipment cost can be reduced.

  Since the drainage pump P can be accommodated in the underpass section UP, even in places where the drainage mechanism cannot be installed around the road

Since the water permeable layer 3 is provided not only in the flat part 23 which is the deepest part of the underpass part UP but also in the inclined part 24 connected thereto, rainwater permeates from the entire surface.
Therefore, the entire surface is not blocked by fallen leaves, dust, mud, etc., and rainwater that has flowed into the underpass portion UP surely permeates from any part of the water permeable layer 3 and other water permeable layer 3 parts. Or it flows into the water flow layer 11a and is drained by the drainage pump P.

Even if the entire surface of the permeable layer 3 of the flat portion 23 is filled with mud that flows simultaneously with rainwater during a guerrilla heavy rain, the inclined portion 24 is rarely buried with mud. Since it penetrates the entire permeable layer 3, the submergence can be made very shallow.
In addition, when the amount of rainfall decreases at the end of the guerrilla heavy rain, the rainwater that flows in does not contain mud, so it can be expected that a part of the mud covering the surface of the permeable layer 3 of the flat part 11 is washed away.

  Since the general pavement 11b is provided on the surface of the water-permeable layer 11a, the durability of the automobile traveling unit 1 can be set to the same level as that of a conventional road. In addition, the porosity and continuous porosity of the water flow layer 11a can be increased. In other words, porous concrete improves water permeability and water storage as the aggregate is roughened and the porosity and continuous porosity are increased, but the surface of the automobile running portion 1 where a large pressure and frictional force is exerted by running of the automobile. When porous concrete is used, the aggregate is peeled off due to wear or the like, and there is a possibility that the durability of the automobile traveling unit 1 is deteriorated and the maintenance cost increases.

FIG. 5 shows a second embodiment of the underpass structure of the present invention.
As shown in FIG. 5, in this road B, the road general portion NR includes a water permeable buffer portion S made of a general asphalt pavement structure or a concrete pavement structure in a portion adjacent to the underpass portion UP. A porous concrete pavement portion 7 is provided so as to sandwich the water permeable buffer portion S with the underpass portion UP.
In addition, the thickness and width of the water permeable buffer portion S are not particularly limited so long as rainwater that has fallen on the upper surface hardly permeates, and rainwater that permeates the porous concrete pavement portion 7 does not permeate the underpass portion UP side. Although not limited, it is preferable to make the width as narrow as possible.

Moreover, the porous concrete pavement part 7 is connected with the water storage part 8 provided in the part adjacent to the road B outside the underpass part UP.
The water reservoir 8 is formed of porous concrete similar to the porous concrete pavement 7.

Perforated pipes may be embedded in the porous concrete layers of the water reservoir 8 and the porous concrete pavement 7.
In addition, the water storage unit 8 is provided with a drainage pump for draining rainwater stored therein, and drains the rainwater stored in the drainage path when it is fine, or uses the drained rainwater for irrigation. It doesn't matter if you do.

Since the road B is provided with the water permeable buffer portion S and the porous concrete pavement portion 7 is provided so as to sandwich the water permeable buffer portion S with the underpass portion UP as described above, the porous concrete pavement portion 7 is provided. The rainwater that falls on the top first penetrates into the porous concrete pavement 7. The rainwater that has permeated the porous concrete pavement 7 is stored in the water storage 8 without flowing to the water permeable layer 3 side of the underpass UP by the water permeable buffer S.
Therefore, rain water falling on the general road portion NR and rain water flowing on the general road portion NB can be prevented from flowing from the periphery of the underpass portion UP to the underpass portion UP side. It can prevent more reliably.

  Moreover, the thickness of the water permeable layer 3 and the porous concrete layer can also be reduced, and the construction cost of the underpass portion UP can be reduced.

6 and 7 show a third embodiment of the underpass structure of the present invention.
As shown in FIGS. 6 and 7, the road C has no drainage basin in the permeable layer 3, and the suction side of the suction-type drainage pump P provided at the high place of the underpass part UP is each perforated. Except for being connected to the end of the pipe 5 and draining rainwater that has entered the perforated pipe 5 by the drainage pump P, it is the same as in the first embodiment.

FIG. 8 shows a fourth embodiment of the underpass structure of the present invention.
As shown in FIG. 8, in this road D, the suction side of the suction-type drainage pump P provided in advance on the side wall W of the underpass part UP is connected to the end of each perforated pipe 5, Except that the rainwater entering the perforated pipe 5 is drained by the drainage pump P, it is the same as in the third embodiment.

The present invention is not limited to the above embodiment. For example, in the above embodiment, the drainage pump may not be provided as long as the void volume of the water permeable layer and the porous concrete layer is sufficient.
Further, in the above embodiment, a drainage basin is provided in the permeable layer on one sidewalk side, and drainage is performed by a drainage pump provided in the drainage basin. A drainage basin and a drainage pump may be provided respectively. That is, if both drainage pumps are moved simultaneously, a smaller and cheaper drainage pump can be used, and even if one drainage pump breaks down, it can be drained to some extent only by the other drainage pump. One drainage pump may be used as a spare.

In the above embodiment, the water storage portion is formed of porous concrete. However, a porous tube may be embedded in the porous concrete layer to increase the water storage volume.
In the above embodiment, a plurality of perforated pipes are embedded in parallel in the horizontal direction, but they may be provided in multiple stages or in a grid pattern. Moreover, you may make it embed | perforate a perforated pipe | tube also in a water-permeable layer.

In the above embodiment, the sidewalk is provided on both sides, but it may be on one side.
In the above embodiment, the underpass portion is three-dimensionally intersected with the railway, but may be three-dimensionally intersected with an expressway or another road, or may be three-dimensionally intersected with both the railroad and the road.

A, B, C, D Road R Railway UP Underpass part NR General road part P Drain pump S Permeation buffer part 1 Car traveling part 11 Flat part 11a Water-permeable layer 11b General pavement 2a, 2b Sidewalk (automobile non-traveling part)
2c Median strip (car non-running part)
21 permeable layer body 22 drainage basin 23 flat part 24 inclined part 3 permeable layer 4 lid 5 perforated pipe 7 porous concrete pavement part 8 water storage part

Claims (8)

  The underpass part includes an automobile traveling part and an automobile non-running part adjacent to each other in the width direction, and includes a flat part at least at the deepest part of the underpass part of the automobile non-running part and an inclined part connected to the flat part. An underpass portion structure of a road, wherein a part of the surface layer is a water permeable layer made of at least porous concrete through which rainwater flowing into an underpass portion of an automobile non-running portion permeates.   The automobile running part has a communication layer made of porous concrete that communicates with the water permeable layer of the automobile non-traveling part in the deepest part of the underpass part, and is embedded in the communication layer so that the perforated pipe straddles the water permeable layer. The underpass part structure of the road of Claim 1 which is.   The underpass part structure of the road according to claim 2, wherein the automobile traveling part is provided with general pavement on the communication layer.   The underpass part structure of the road in any one of Claims 1-3 provided with the drainage pump which drains the rainwater which flowed into the permeable layer.   The underpass portion structure of a road according to claim 4, wherein the drainage pump is installed in a drainage basin having a lid made of porous concrete.   The road underpass structure according to any one of claims 1 to 5, wherein the porous concrete portion of the water permeable layer is formed of porous concrete having an upper layer made of finer aggregate than the lower layer and having a small gap diameter. .   The road underpass structure according to claim 6, wherein the porous concrete forming the water permeable layer has a porosity of 20% to 35%. The road underpass structure according to any one of claims 1 to 7, wherein the vehicle non-traveling portion is at least one of a median strip, a sidewalk, a bicycle path, and a roadside belt.

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