JP2009167691A - Revetment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a revetment capable of improving the water quality of a water area in a deficient oxygen state. <P>SOLUTION: In the revetment 1, when the level of water in a canal C is gradually raised from the minimum level (L.W.L), water advances from a water entrance 8b into a water flow passage 8, and the flow of the water in the water flow passage 8 is stopped by a reverse flow prevention valve 9. When the level of water in the canal C is raised near the maximum level (H.W.L), water flows into a water inflow part 4 over a dam body 3. In this case, since the water and oxygen are agitated, the water flowing into the water inflow part 4 is formed in an enriched oxygen water. When the level of water in the canal C lowers near the minimum level (L.W.L), the water advancing into the water flow passage 8 is discharged from the water entrance 8b, and the enriched oxygen water flows from the water inflow part 4 into the canal C through the reverse flow prevention valve 9 and the water flow passage 8. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a bank protection provided in a water area where the water level fluctuates, such as a canal, a river, and a lake.

As a conventional revetment in the above technical field, one formed in a stepped shape so as to become lower toward the water body side is known (for example, see Patent Document 1). According to such a revetment, since the contact area between water and oxygen increases due to fluctuations in the water level, it is possible to improve the quality of water in anoxic water areas.
JP 2004-68272 A

  However, for the revetment in the above technical field, further improvement of the water quality of the poor oxygen state is required.

  Then, this invention is made | formed in view of such a situation, and it aims at providing the revetment which can improve the water quality of the water area of an anoxic state.

  In order to achieve the above object, a revetment according to the present invention is a revetment provided in a water area where the water level fluctuates, and a first bank body formed to be higher than the highest water level of the water area, A second levee body formed on the water body side with respect to the first dam body so as to be higher than the lowest water level and lower than the highest water level of the water body, and the first dam body and the second dam body A water inflow portion formed between the water inflow portion having a bottom surface that is higher than the lowest water level of the water body and lower than the second levee body, and is formed to communicate with the water inflow portion and the water area, and is higher than the lowest water level of the water area. And a water flow passage having a water side water outflow inlet that is lower than the water inflow portion, and a backflow prevention valve that is provided in the water flow passage and prevents water from flowing through the water flow passage when water enters the water flow passage from the water side water outflow inlet. It is characterized by providing.

  In this revetment, when the water level of the water area gradually rises from the lowest water level, water enters the water flow path from the water side water outflow inlet, and the water flow in the water flow path is blocked by the backflow prevention valve. And if the water level of a water area rises to the vicinity of the highest water level, water will flow into a water inflow part exceeding the 2nd bank body formed in the water area side with respect to the 1st bank body. At this time, since water and oxygen are agitated, the water flowing into the water inflow portion has an oxygen-rich water quality. After that, when the water level in the water area descends to the vicinity of the minimum water level, the water that has entered the water flow passage is discharged from the water flow side water outflow inlet, so that the oxygen-rich water is discharged through the backflow prevention valve and the water flow passage. Returned from the inflow to the water. Therefore, according to this revetment, it is possible to improve the quality of water in anoxic water areas.

  In the revetment which concerns on this invention, it is preferable that the 2nd bank body is formed in step shape so that it may become low toward a water inflow part. In this case, since the water exceeding the 2nd bank body will fall a step-shaped part by the time it reaches a water inflow part, stirring with water and oxygen is further accelerated | stimulated. Furthermore, the contact area between water and oxygen increases on the tread surface of the stepped portion. By these, the water which flowed into the water inflow part can be made more oxygen-rich water quality.

  At this time, it is preferable that a water reservoir is formed on the tread surface of the second bank body. In this case, even if the water level in the water area falls to the vicinity of the lowest water level and the oxygen-rich water quality is returned from the water inflow portion to the water area, oxygen-rich water quality remains in the water reservoir. Accordingly, it is possible to inhabit the water reservoir that has entered the water with the water beyond the second bank.

  In the revetment according to the present invention, the backflow prevention valve is preferably provided at the water inflow portion side water outflow inlet of the water flow passage so that the outer water outflow inlet is higher than the bottom surface of the water inflow portion. In this case, even if the earth and sand etc. enter the water inflow portion with the water beyond the second dam body, the earth and sand will not easily enter from the outside water outflow inlet of the backflow prevention valve. It is possible to prevent the passage from being blocked. Moreover, since the backflow prevention valve is provided at the water inflow portion side water outflow inlet of the water passage, maintenance of the backflow prevention valve can be easily performed.

  At this time, it is preferable that the bottom surface of the water inflow portion is inclined so as to become lower toward the position where the backflow prevention valve is installed. In this case, oxygen-rich water can be reliably returned from the water inflow portion to the water area via the backflow prevention valve and the water flow passage.

  In the revetment which concerns on this invention, it is preferable that the water flow path inclines so that it may become low toward a water area. In this case, even if soil or the like enters the water flow passage from the water inflow portion side, the soil or the like easily flows to the water area side, so that the backflow prevention valve or the water flow passage can be prevented from being blocked by the sand or the like. .

  In the revetment according to the present invention, a plurality of water passages are formed, and it is preferable that a backflow prevention valve is provided in each of the water passages. In this case, even if the backflow prevention valve and the water flow passage of one system are blocked by sediment or the like, the oxygen-rich water is reliably returned from the water inflow portion to the water area through the backflow prevention valve and the water flow passage of the other system. be able to.

  ADVANTAGE OF THE INVENTION According to this invention, the water quality of the water area of an anoxic state can be improved.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected to the same or an equivalent part, and the overlapping description is abbreviate | omitted.

  FIG. 1 is a longitudinal sectional view of an embodiment of a revetment according to the present invention, and FIG. 2 is a plan view of the revetment of FIG. As shown in FIGS. 1 and 2, a plurality of revetments 1 are arranged in parallel along a canal (water area) C leading to an inner bay. The water level of Canal C fluctuates due to tides. That is, the water level of canal C is the highest water level (HWL) at high tide and the lowest water level (LWL) at low tide.

  The revetment 1 has a levee body (first dam body) 2 formed so as to be higher than the highest water level of the canal C, and is higher than the lowest water level of the canal C and lower than the highest water level of the canal C. A bank body (second bank body) 3 formed on the side of the canal C with respect to the bank body 2 and a water inflow portion 4 formed between the bank body 2 and the bank body 3 are provided. The water inflow portion 4 has a bottom surface 4 a that is higher than the lowest water level of the canal C and lower than the dam body 3.

  The bank body 3 is formed in a step shape so as to become lower toward the water inflow portion 4. Here, two stepped portions 5 are provided. On the tread surface 5a of each step-like portion 5, a water storage portion 6 that is a concave portion having a rectangular cross section is formed. A plurality of notches 7 a are formed along the canal C at the top 7 of the dam body 3.

  A water passage 8 is formed in the dam body 3 so as to communicate the water inflow portion 4 and the canal C. One end of the water flow passage 8 is a water outflow inlet (water inflow portion side water outflow inlet) 8a that opens to the bottom surface 4a of the water inflow portion 4, and the other end of the water flow passage 8 is the vertical side of the dam body 3 on the canal C side. It is a water outflow inlet (water area side water outflow inlet) 8b that opens to the wall surface. The water flow passage 8 is inclined so as to become lower toward the canal C, and the water outflow inlet 8 b is higher than the lowest water level of the canal C and lower than the water inflow portion 4.

  A backflow prevention valve 9 is provided at the water outflow inlet 8 a of the water passage 8. The water outflow inlet (outside water outflow inlet) 9 a of the backflow prevention valve 9 is higher than the bottom surface 4 a of the water inflow portion 4. FIG. 3 is a cross-sectional view of the revetment along the line III-III in FIG. As shown in FIG. 3, the bottom surface 4 a of the water inflow portion 4 is inclined so as to become lower toward the position where the backflow prevention valve 9 is installed.

  FIG. 4 is a vertical cross-sectional view of the check valve of the revetment in FIG. As shown in FIG. 4, the backflow prevention valve 9 has a stepped cylindrical container 11 installed so as to cover the water outflow inlet 8 a of the water flow passage 8. The water outflow inlet 9 a is formed in the top plate portion of the small diameter portion 11 a of the container 11. A spherical floating body valve 12 that is guided by the inner surface of the small diameter portion 11 a of the container 11 and closes the water outflow inlet 9 a is accommodated in the container 11. In the large-diameter portion 11b of the container 11, a mesh body 13 for restricting the movement of the floating valve 12 toward the water outflow inlet 8a of the water flow passage 8 is provided.

  In the backflow prevention valve 9, when the water level of the canal C gradually rises from the lowest water level and water enters the water flow passage 8 from the water outflow inlet 8 b, the floating valve 12 is guided by the inner surface of the small diameter portion 11 a of the container 11. The entrance / exit 9a is closed. That is, the backflow prevention valve 9 prevents water from flowing through the water flow passage 8 when water enters the water flow passage 8 from the water outflow inlet 8b.

  The operation and effect of the revetment 1 configured as described above will be described.

  When the water level of the canal C gradually rises from the lowest water level, water enters the water passage 8 from the water outflow inlet 8b, and the water flow in the water passage 8 is blocked by the backflow prevention valve 9. That is, since the water outflow inlet 9 a is closed by the floating body valve 12, poor-oxygen water quality does not enter the water inflow portion 4 from the canal C through the water flow passage 8 and the backflow prevention valve 9. And if the water level of the canal C rises to the vicinity of the highest water level, water will flow into the water inflow part 4 step by step over the bank body 3. That is, first, water flows into the water inflow portion 4 from the cutout portion 7 a of the dam body 3, and then water flows into the water inflow portion 4 beyond the top portion 7 of the dam body 3. At this time, since the dam body 3 is formed in a step shape so as to become lower toward the water inflow portion 4, the water falls on each step-like portion 5, and the water and oxygen are stirred. The contact area between water and oxygen increases on the tread surface 5a of the shaped portion 5. As a result, the water flowing into the water inflow portion 4 has an oxygen-rich water quality. Thereafter, when the water level of the canal C descends to the vicinity of the lowest water level, the water that has entered the water flow passage 8 is discharged from the water outflow inlet 8b, and the water flow in the water flow passage 8 is released. That is, since the blockage of the water outflow inlet 9 a by the floating body valve 12 is released, oxygen-rich water of water flows from the water inflow portion 4 into the canal C through the backflow prevention valve 9 and the water flow passage 8. At this time, since the bottom surface 4a of the water inflow portion 4 is inclined so as to become lower toward the position where the backflow prevention valve 9 is installed, the water flowing into the water inflow portion 4 is reliably returned to the canal C. As described above, according to the revetment 1, the water quality of the canal C in the poor oxygen state can be improved.

  Moreover, since the water storage part 6 is formed in the tread surface 5a of each step-like part 5, the water level of the canal C descends to the vicinity of the lowest water level, and oxygen-rich water is discharged from the water inflow part 4. Even if the water is returned to the canal C, water of oxygen-rich water quality remains in each water reservoir 6. Therefore, the organisms that have entered with the water beyond the dam body 3 can be inhabited in each water storage section 6.

  Further, since the water outflow inlet 9a of the backflow prevention valve 9 is higher than the bottom surface 4a of the water inflow portion 4, even if earth and sand enter the water inflow portion 4 through the dam body 3 together with water, the earth and sand are not It becomes difficult to enter from the water outflow inlet 9a of the backflow prevention valve 9. Therefore, it is possible to prevent the backflow prevention valve 9 and the water flow passage 8 from being blocked by earth and sand.

  Even if soil or the like enters the backflow prevention valve 9 from the water outflow inlet 9a, the mesh body 13 functions as a filter to prevent the sand or the like from entering the water flow path 8, or the mesh body 13 Since crushing and subdividing are performed, blockage of the water flow passage 8 due to earth and sand is prevented. At this time, since the backflow prevention valve 9 is provided at the water outflow inlet 8a of the water flow passage 8, the backflow prevention such as removal of earth and sand entering the backflow prevention valve 9 and replacement of the mesh body 13 in the water inflow portion 4 is performed. Maintenance of the valve 9 can be easily performed.

  Further, since the water flow passage 8 is inclined so as to become lower toward the canal C, even if earth and sand or the like enter the water flow passage 8 from the water inflow portion 4 side, the earth and sand easily flows to the canal C side. Therefore, it is possible to prevent the backflow prevention valve 9 and the water flow passage 8 from being blocked by earth and sand. In addition, if a groove or a protrusion is provided on the inner surface of the water flow passage 8 in a spiral shape, a swirling flow is generated when the water flows, so that the backflow prevention valve 9 and the water flow passage 8 are not blocked by earth or sand. This can be prevented more reliably.

  The present invention is not limited to the embodiment described above.

  FIG. 5 is a longitudinal sectional view of another water storage unit applied to the revetment of FIG. 1. As shown in FIG. 5, the water storage unit 21 is provided on a wall surface that can be immersed in the revetment 1 when the water level of the canal C fluctuates, and a water receiving unit 22 in which water is stored after immersion, and It has the air receiving part 23 in which air is stored during immersion. In each water storage part 21, since the water receiving part 22 and the air receiving part 23 are facing, the water stored in the water receiving part 22 becomes an oxygen-rich water quality. Therefore, if the water storage part 21 is provided on the wall surface that can be immersed in the revetment 1 when the water level of the canal C fluctuates, small organisms such as corals can be inhabited in the water storage part 21.

  Moreover, the backflow prevention valve 9 applied to the revetment 1 is not limited to what has the structure mentioned above. FIG. 6 is a longitudinal sectional view of another backflow prevention valve applied to the revetment in FIG. 1. As shown in FIG. 6A, the backflow prevention valve 9 may have a lid body 14 that can be opened and closed only on the water outflow inlet 8 a side of the water flow passage 8. Further, the backflow prevention valve 9 may have a floating valve 12 having a circular truncated cone shape as shown in FIG. 6B instead of the spherical floating valve 12. As shown in FIG. 6 (c), it may have a floating valve 12 having a shape in which a column is provided on both sides of a disk.

  In the revetment 1, a plurality of water flow passages 8 are formed, and a backflow prevention valve 9 may be provided in each water flow passage 8. In this case, even if one system of the backflow prevention valve 9 and the water flow passage 8 is blocked by sediment or the like, oxygen-rich water is supplied from the water inflow portion 4 through the backflow prevention valve 9 and the water flow passage 8 of another system. It can be reliably returned to Canal C.

  Further, a tread surface 5 a of the step-like portion 5 of the dam body 3 may be provided with a housing or a bag body in which granular materials such as gravel are stored instead of the water storage portion 6. Moreover, the bank 3 may be inclined so as to become lower toward the water inflow portion 4.

  Moreover, the revetment 1 is not limited to what is applied to the canal C, but can be applied to a water area where the water level fluctuates regardless of whether it is natural or artificial, such as a river or a lake.

It is a longitudinal section of one embodiment of a revetment concerning the present invention. It is a top view of the revetment of FIG. It is sectional drawing along the III-III line of the revetment of FIG. It is a longitudinal cross-sectional view of the reverse flow prevention valve of the revetment of FIG. It is a longitudinal cross-sectional view of the other water storage part applied to the revetment of FIG. It is a longitudinal cross-sectional view of the other backflow prevention valve applied to the revetment of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Revetment, 2 ... Embankment body (1st embankment body), 3 ... Embankment body (2nd embankment body), 4 ... Water inflow part, 4a ... Bottom surface, 5a ... Tread surface, 6 ... Water storage part, 8 ... Water flow passageway, 8a ... Water outflow inlet (water inflow side water outflow inlet), 8b ... Water outflow inlet (water area side water outflow inlet), 9 ... Backflow prevention valve, 9a ... Water outflow inlet (outside water outflow inlet), C ... Canal (water area) .

Claims (7)

A revetment in a water area where the water level fluctuates,
A first levee body formed to be higher than a maximum water level of the water area;
A second levee body formed on the water area side with respect to the first dam body so as to be higher than a minimum water level of the water area and lower than a maximum water level of the water area;
A water inflow portion formed between the first levee body and the second dam body, having a bottom surface higher than the lowest water level of the water area and lower than the second dam body;
A water flow passage formed to communicate with the water inflow portion and the water area, and having a water area side water outflow inlet that is higher than the lowest water level of the water area and lower than the water inflow section;
A revetment provided in the water flow passage, and comprising a backflow prevention valve that prevents water from flowing through the water flow passage when water enters the water flow passage from the water outlet on the water side.   The revetment according to claim 1, wherein the second bank body is formed in a step shape so as to become lower toward the water inflow portion.   The revetment according to claim 2, wherein a water reservoir is formed on a tread surface of the second bank body.   The said backflow prevention valve is provided in the water inflow part side water outflow inlet of the said water flow path so that the outer side water outflow inlet may become higher than the said bottom face of the said water inflow part. Revetment according to any one of the items.   The revetment according to claim 4, wherein the bottom surface of the water inflow portion is inclined so as to become lower toward a position where the backflow prevention valve is installed.   The revetment according to any one of claims 1 to 5, wherein the water passage is inclined so as to become lower toward the water area. A plurality of the water flow passages are formed,
The revetment according to any one of claims 1 to 6, wherein each of the water flow passages is provided with the backflow prevention valve.

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