JP4758882B2 - Revetment block with fishway and construction method of revetment surface with fishway using the same - Google Patents

Description

  The present invention relates to a revetment block capable of securing a fishway through which small fish can run up in a waterway revetment or a lake revetment, and a construction method of a revetment with a fishway using the block.

  In the traditional waterside environment, small fish such as loaches that live in paddy fields and the surrounding flooded / flowing channels freely migrated between streams and rivers into which flooded water flows. This was possible because the flow of water from the paddy field to the creek, etc. via the flooded water / flow channel was moderately continuous. If there is such a flow of water, division of the habitat is inevitable.

  In other words, in recent years, riverbeds have often been dug down for reasons such as securing an allowable water level during river improvement, and as a result, natural dredging has been replaced by artificial dredging such as dredging and flume. In the state where it protruded far above the water surface, etc., it began to flow with a large drop.

  Therefore, in order to eliminate such a discontinuous state, for example, it has been proposed to install a fishway inclined downward from the top of the weir toward the downstream riverbed on the revetment wall provided on the downstream side of the large fixed weir. (Patent Document 1). In addition to the advantage that this simple fishway device can be easily attached to an existing weir, etc., the fishway having a V-shaped cross section is formed into a staircase shape by a plurality of partition walls connected to the inside thereof. It is considered that there is an advantage that a small fish can easily go up.

Japanese Utility Model Publication No. 6-46036 (Claim 1, FIG. 1)

  Since the simple fishway device according to Patent Document 1 is formed temporarily, it does not become an obstacle if it is removed when water is increased. However, it has a disadvantage that it is vulnerable to a collision with a falling object and management becomes complicated. In addition, depending on the height of the weir, the fishway has a steep slope. On the other hand, if it is avoided to secure a gentle slope, the length of the fishway becomes extremely long.

  In view of such circumstances, in the present invention, it is possible to constantly secure a fishway that eliminates the drop on the waterway revetment and lake revetment surface where a large drop is likely to occur between the stream and the flooded water poured into the stream. The main problem is to provide a revetment block with a fishway that does not cause obstacles to water flow such as creeks by suppressing protrusions into the water flow section.

  In order to solve the desired problem, the revetment block with a fishway according to the present invention is partitioned by a plurality of partition portions provided at a height lower than the upper edge of the front plate forming a vertical wall, while A fishway waterway that is inclined downward in one of the left and right directions along the inner side, a landing part deeply provided in the rear on the upstream side of the fishway waterway, and a rear surface part excluding the fishway waterway and the landing part In addition, it shall consist of a loading section for the pile protection bank block. By connecting the tip of the pipe or flume or the downstream side of the fishway channel in the stacked block to the landing, a gentle flow channel was secured to eliminate the direct drop.

  Here, the vertical wall of the revetment block does not need to have a strict vertical surface, and does not obstruct the flow of a stream or the like, and may be upright so as to avoid a collision of a falling object. In addition, the bottom surface of the fishway channel does not have to be inclined according to the inclination angle, and may be a horizontal plane that also serves as a block bottom plate. As a plurality of partitioning portions, in addition to plate-like ones, pseudo-stone-like ones may be used, as long as the line connecting the tops is inclined downward while staying at a height lower than the upper edge of the front plate, Small fish and the like can go up the fishway channel by moving to the next section with a high water level while swimming over the partition in order.

  The revetment block with a fishway is open at the rear of the fishway waterway, and when the revetment block with a different inclination direction is stacked on the mounting part, the front plate of the revetment block located above is the rear blocking plate of the fishway waterway Can be formed to function as. Forming a fishway channel with a narrow width (depth) into a plurality of rooms with partition plates complicates the formwork at the time of manufacture, while revetment blocks are stacked while shifting the revetment blocks backward In view of these characteristics, a fishway channel is formed by a combination of upper and lower blocks.

  And the flat mounting part in these revetment blocks with a fishway can be a bottomed or non-bottomed cylindrical hollow part, and in this case, the said cylindrical cavity part is used as a custody part, such as crushed stone By making it function, a sufficient weight can be secured for each revetment block alone.

  Moreover, in the construction method of the revetment surface with a fishway according to the present invention, by using the revetment block with a fishway as described above, the blocks having different inclination directions are alternately stacked in a staircase shape so that the front side is folded. A continuous fishway channel was formed. For example, a revetment block having a fishway channel inclined downward to the right is used as a first block, and a revetment block having a fishway channel inclined downward to the left is loaded as a second block. If the same type of revetment block as the block is stacked as a third block, a fishway channel that is continuously folded is formed through the landing section in each revetment block.

  According to the revetment block with a fishway according to the present invention, the fishway waterway is placed in the front plate that forms a vertical wall, so that the protrusion of the riverway or the like into the water flow section is suppressed, and the presence of the fishway becomes a running-water obstacle. Can be prevented. In addition, since the fishway channel was formed by combining the revetment blocks loaded in the vertical direction, the structure of one revetment block could be simplified.

  And when a flat mounting part that functions when a plurality of parts are stacked in the vertical direction is a bottomed or non-bottomed cylindrical hollow part, a sufficient weight and a conservative length can be secured. It can maintain the water control function required for revetment and revetment.

  In addition, according to the method for constructing a revetment surface with a fishway according to the present invention using the revetment block, even when a large drop occurs between the revetment height, i.e., the river and the submerged water poured into it, A fishway canal that has a gentle slope and a shallow depth can be secured by a continuous fishway canal.

  Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view showing an example of a seawall block with a fishway according to the present invention. The revetment block with a fishway in this example is a type in which the fishway channel is inclined from the upper left to the lower right, and a front plate 1 that forms a vertical wall and a rear plate 2 that is erected in parallel with the front plate 1. The right side plate 3 and the left side plate 4 connecting both members are formed in a substantially rectangular shape in plan view. Although not shown in the figure, a bottom plate is provided at least in the fishway channel portion to secure a water pool for the small fish to go up.

  In other words, the fishway channel 5 inclined downward from left to right along the inner side of the front plate 1 has a lower height than the upper edge 11 of the front plate 1 and protrudes backward from the front plate 1. It is divided into three parts by two partition portions 6 erected from the face plate. The position and number of the partitioning portions 6 can be appropriately selected according to the shape and size of the revetment block, but by keeping the top of the partitioning portion 6 at a height lower than the upper edge 11 of the front plate 1. The water from above flows exclusively through the fishway channel 5 while exceeding the partition 6.

  On the upstream side of the fishway waterway 5 (left side in FIG. 1), a landing 7 is provided. This landing part 7 is also secured to a depth that allows a sufficient water pool to be formed so that small fish can swim and rest, as can each room part partitioned by the partition part 6. Yes. Considering that the lower end of the fishway channel 5 in the revetment block stacked on the landing site 7 is connected, the landing site 7 is deeply provided behind the revetment block. However, the remaining rear part which secured the horizontal width of the fishway channel 5 in the piled revetment block is set as a hollow 8 for intrusion.

  In order to reliably support the revetment block to be stacked on the rear surface portion excluding the fishway channel 5, the landing section 7 and the trunk cavity 8 arranged in an L shape, the upper edge of the frame surrounding the three directions is used. A placement portion 9 having a horizontal plane is provided. In the revetment block of the present example, the inside of the placing portion 9 is also a bottomed or bottomless cylindrical hollow portion, which corresponds to the inclusion of crushed stone or the like.

  Although the rear of the fishway waterway 5 is open, when the bank block whose inclination direction is reversed horizontally with respect to the bank block shown in FIG. 1 is stacked, the mounting portion 9 is provided on the rear side. The front plate of the revetment block that will be located above functions as a rear blocking plate for the fishway channel 5. Therefore, the depth length of the partition part 6 is set to the length which contacts the front board 1 of the upper revetment block used as a back obstruction | occlusion board.

  FIG. 2 is a perspective view showing an example of construction using the above-described revetment block. By stacking blocks in which the inclination direction of the fishway channel 5 is reversed left and right alternately in a staircase pattern, It shows a state where a fishway channel that continues to be folded is formed on the front side of the revetment. Thus, the revetment block with a fishway according to the present invention is used in place of a part of the ordinary revetment block G, and reaches the tip of the dredger pipe H guided from the flooded water W continuous from the paddy field S. It is installed by stacking to the height to be. It is desirable that the tip of the culvert pipe H is connected to the landing section 7 in the revetment block located at the uppermost stage, so that the culvert pipe H and the landing section 7 are connected with almost no drop.

  In addition, each revetment block uses the same size in the front, rear, left and right, but only the inclination direction of the fishway channel is different. It is also possible to use a revetment block with a longer depth, a shorter depth on the upper side, and a different depth.

  FIG. 3 is a perspective view showing a state in which revetment blocks using pseudo stones having different sizes are stacked as the partitioning portion 6. By using the pseudo stones having different sizes and shapes as the partitioning portion 6, the fishway channel 5 rich in change is realized. The fishway channel 5 is formed in a V-shaped cross section so that a water reservoir can be secured even with a small partition 6.

It is the perspective view which showed an example of the revetment block with a fishway concerning this invention. It is a perspective view which shows the construction state of the bank protection block of FIG. It is a perspective view which shows the state which piled up another example of the revetment block with a fishway which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Front board 2 Back board 3 Right side board 4 Left side board 5 Fishway waterway 6 Partition part 7 Landing part 8 Cavity 9 Placement part

Claims (4)

A fishway channel formed by a plurality of partitions provided at a height lower than the upper edge of the front plate forming a vertical wall and inclined downward in either one of the left and right directions along the inner side of the front plate, and the fishway A revetment block with a fishway comprising a landing part deeply provided in the rear on the upstream side of the waterway, and a mounting part for an upper pile revetment block provided on the rear surface portion excluding the fishway waterway and the landing part. The rear side of the fishway channel is open, and when the revetment blocks with different inclination directions are stacked on the mounting part, the front plate of the revetment block located above functions as a rear blockage plate for the fishway channel. The revetment block with a fishway according to claim 1. The revetment block with a fishway according to claim 1 or 2, wherein the flat placement portion is a bottomed or bottomless cylindrical hollow portion. Using the revetment block with a fishway according to any one of claims 1 to 3 and alternately stacking blocks having different inclination directions in a staircase shape, a fishway waterway that continues to be folded on the front side is formed. How to build a revetment with a fishway.

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