JP6429198B2 - Fishway structure - Google Patents

Description

  The present invention relates to a fishway structure and the like installed in a head portion formed in a water stream (for example, a river crossing structure such as a dam, a weir, a head work, etc.). More specifically, the present invention relates to a fishway structure or the like in which a stagnant region is continuously formed in a stepped manner from the upper water level height to the lower water level height of the head portion.

  For example, in rivers, there are many river crossing structures such as dams, weirs, and dropheads for water use such as hydroelectric power generation, irrigation, water intake, water supply, and flood control, river maintenance, water level adjustment, etc. It is built. However, while these river crossing structures are effective in terms of water use and flood control, in order to divide the river in the middle, especially when migratory fish moving back and forth between rivers and between river seas go up and down. Hinder and adversely affect the ecosystem.

  Therefore, in recent years, when a river is divided by a river crossing structure, a fishway structure is often attached to the river crossing structure so that the migratory fish can be run up. Here, the fishway structure means a structure provided with a passage capable of moving up and down, such as migratory fish.

  For example, Patent Document 1 discloses a fishway structure in which a plurality of concrete block bodies having hollow portions communicating from the inside to the outer surface are disposed, and a downwardly inclined flow path is formed from the upstream side toward the downstream side by the hollow portions. In Patent Document 2, a prefabricated concrete fishway block using a precast concrete fishway block is provided. In Patent Document 3, a water reservoir is provided on the top end surface of the block main body, and a natural water is provided in front of the water reservoir on the top end surface of the block main body. A fishway block in which stones are bonded and fixed to form a non-overflow portion is described.

Patent Document 4 discloses a fishway structure including a fishway having a stepped portion provided in a staircase shape and a standing wall, and Patent Document 5 discloses a plurality of pools having a staircase shape in a direction along a water channel. A parallel staircase type fishway that is arranged in parallel with a plurality of staircase type fishways arranged in parallel with each other is provided with a water channel part and a side wall part in Patent Document 6 and has a flow retention part, and in the vicinity of the side wall part Each fishway has a fast flowing part.
Japanese Patent Laid-Open No. 11-117272 JP-A-62-280239 Registered Utility Model No. 3030791 JP 2008-184762 JP 2005-113675 A JP 2002-206229 A

  Since the cross-river structure needs to have long-term durability against water pressure and overflow water as a basic performance, it is generally constructed firmly with concrete as the main material. The fishway structure is generally built at the same time as the river crossing structure, and it is built on the assumption that it will be used as a passage for migratory fish for a long time. In particular, concrete is generally constructed firmly with concrete as the main material for the foundation.

  However, new heads due to poor management, design problems, sedimentation of sediment, driftwood, etc. in the fishway, fluctuations in water level / volume, movement / change in position of the stream, sediment accumulation near the fishway entrance, bottom settlement, etc. The fact is that the majority of the fishway structures have lost their functions as fishways in a relatively short period of time after construction due to the formation of.

  In order to restore the function of the fishway structure as a fishway, it is necessary to newly construct and repair the fishway structure, resulting in a large labor and cost burden. Therefore, the reality is that many fishway structures are left with their functions lost.

  Therefore, an object of the present invention is to provide a fishway structure that can build or restore the function as a fishway at low head and low cost in a head portion formed in a water flow such as a river crossing structure. .

In the present invention, a fishway structure installed in a head portion formed in a water flow,
A pedestal portion and a plurality of stagnant portions, wherein the pedestal portion is a staircase of a gabion-like member filled with stone gravel or a gravel-like filling material in a rod-like body substantially entirely closed with a net-like member The water-spilling part flows in from the upper side by mounting a water-impervious bag-like body formed in the upper part of the inside of the bowl-like part formed in the upper part of the net-like member. The water level height on the upper side of the head portion is provided by arranging the water-stagnation part on the horizontal surface of each stage of the stage formed by laying the pedestal part. A fishway structure or the like in which a stagnant region is continuously formed in a staircase shape from the water level to the lower water level is provided.

  In the present invention, the stagnant region is continuously formed in a staircase pattern from the upper water level height to the lower water level height of the head portion. Therefore, for example, the uppermost stagnant part is placed close to the upper side of the head part so that the water flow at the start of the fall gently flows into the uppermost stagnant part, and each stagnant part including the uppermost part is First, by defining the overflow direction of water from the stagnant part by denting a part of the entire circumference of the upper edge downward from the other upper edge part, The water flow or a part of it flows into the uppermost stagnant part, and further, the water flow passes over the recessed part of the upper edge of the stagnant part and flows into the stagnant part in the next lower stage. The water flows continuously to the bottom of the stagnant part, and a continuous water flow is formed up to the water level height below the head part.

  And, the stagnant water area where fish can rest is formed in each step, and the flow velocity is reduced by dropping the water flow in a staircase shape, so for example, each step formed between the stagnant portions By setting the target fish to a height that allows the fish to fly, the fish will fly while resting in each water catchment, climbing each waterlogging step by step, and finally reaching the top of the head Can do. As a result, it is possible to overcome the head of the river crossing structure and the like formed in the water flow, and to continue upstream without being divided.

  In this fishway structure, the pedestal is formed by stacking gabion-like members filled with stone gravel or a gravel-like filling material in a rod-like body whose entire surface is substantially closed with a net-like member. Thereby, the whole shape can be maintained for a certain period of time against water pressure and overflow water.

  Also, for example, sandwiching rods are sandwiched at the boundary portions between the stacked gabion-like members, and each end of each sandwiching rod is projected to the side surface side of the pedestal portion, and each sandwiching rod By fixing each end to a connecting bar stretched between the projecting end portions, the entire shape can be easily and more firmly held by reinforcing the fishway structure.

  In the present invention, the pedestal part is formed of a net-like member and a filling material, and the stagnant part is formed of a net-like member and a water-impervious bag-like body, and the fishway structure is formed by stacking them. It can be installed in a short period of time, including when it is newly installed in a place where the fishway structure has not been built, and can be installed with low labor and low cost.

  In addition, this fishway structure can be formed by stacking the pedestal part and arranging the water-stagnation part on the horizontal plane of each stage, so compared with the fishway structure constructed with conventional concrete as the main material , It is easy to change and adjust the installation location and shape, and has a high degree of freedom. Therefore, even after the installation of this fishway structure, it can be improved easily and appropriately against structural problems and design problems exposed after construction, fluctuations in water level and water volume, movement and change in position of water flow paths, etc. Corrections can be made. In addition, it is easy to change the shape after building this fishway structure, and to repair, move, and withdraw, so the function of the fishway is lost due to poor management, sedimentation of sediment, driftwood, etc. in the fishway, the fishway Even when a new head is formed due to sediment accumulation or bottom settlement near the entrance, the function as a fishway can be reconstructed or restored simply, with low labor and at low cost. In addition, when a fishway structure constructed using conventional concrete as the main material loses its function as a fishway, the fishway structure according to the present invention is installed at the relevant place instead of performing a large-scale new construction or repair work. By doing so, the function as a fishway can be recovered with low labor and low cost.

  According to the present invention, the function as a fishway can be constructed or restored simply, with low labor and at low cost.

  The present invention is a fishway structure installed in a head portion formed in a water flow, and has a pedestal portion and a plurality of water-stagnation portions, and the pedestal portion is substantially blocked by a mesh member. It is formed by stacking gabion-like members filled with stone gravel or a gravel-like filling material in a staircase, and the stagnant part is a net-like member formed of a net-like member. A horizontal surface of each step of the steps formed by laying the pedestal part is formed so that the water flowing in from the upper side can be retained by mounting a water-impervious bag-like body formed on the inner side. By including the water-stagnation part on the top, it includes all the fishway structures in which the water-spilling area is continuously formed in steps from the upper water level to the lower water level of the head part. To do.

  Examples of embodiments of the present invention will be described below with reference to FIGS. In addition, this invention is not limited narrowly only to embodiment illustrated below.

  FIG. 1 is a schematic external perspective view showing an example of a fishway structure according to the present invention, and FIG. 2 is a schematic cross-sectional view in the same water flow direction.

  The fishway structure A in FIGS. 1 and 2 is installed in the head part B1 formed in the water flow W in the X1 direction by the river crossing structure B, and the pedestal part 1 and the five water-stagnation parts 2 (21, 22, 23, 24, 25), and the pedestal portion 1 is a gabion-like member 11 in which a gravel or a gravel-like filling material 17 is filled in a bowl-like body 16 whose entire surface is substantially closed by a net-like member. , 12, 13 and 14 are stacked in a staircase shape, and each water-stagnation part 2 is formed in a water-impervious bag shape formed in the upper part of the inside of the bowl 26 formed in the upper part of the net-like member. By attaching the body 27, the water flowing in from the upper side is formed so as to be retained, and the stagnant portions 2 are respectively arranged on the horizontal surfaces 15 of the respective steps formed by laying the pedestal portion 1. Thus, the stagnant region is continuously formed in a step shape from the water level height on the upper side B11 to the water level height on the lower side B12 of the head portion B1.

  Note that the present invention is only used when, for example, as shown in FIG. 1 or FIG. 2, the installation is performed in a place where a head portion B1 is formed in the water flow W by a river crossing structure B such as a dam, a weir, or a head work. It is not limited narrowly and, in principle, widely includes a case where it is installed at any place where the head portion B1 is formed in the water flow regardless of whether it is an artificial structure or not.

  The pedestal portion 1 is a base portion of the staircase-like fishway structure A according to the present invention, and is formed by stacking the gabion-like members 11 to 14 in a staircase shape.

  The gabion-like members 11 to 14 have a configuration in which a gutter-like body 16 whose whole surface is substantially closed with a net-like member is filled with stone gravel or a gravel-like filling material 17.

  The bowl-like body 16 forming the gabion-like members 11 to 14 is a bowl-like member filled with stone gravel or a gravel-like filling material 17 and is formed by substantially closing the entire surface with a net-like member.

  The assembling procedure of the bowl-shaped body 16 is not particularly limited. For example, a plurality of panel-like net members constituting the bottom surface, each side surface, and the top surface may be fastened with a known string-like member as it is or while being bent. It can be formed by going.

  The net-like member forming the bowl-like body 16 is not particularly limited as long as it can hold the filling material 17 without escaping. For example, a well-known thing can be widely adopted, for example, a mesh having a substantially rhombus shape or a substantially hexagonal shape.

  As for the thickness and material of the mesh member, well-known ones can be widely used and are not limited to a narrow one. As the material of the mesh member, for example, iron wire, copper wire, stainless steel wire, galvanized iron wire, a wire material coated with plastic such as vinyl, or a plastic wire can be widely used.

  In the present invention, the mesh member may be formed of a high strength material. As the high-strength material, for example, a plastic wire, a wire covered with plastic, and the like are preferable, and for example, a polyester monofilament that is one of the plastic wires is more preferable.

  Polyester monofilament is a thermoplastic engineering plastic produced using dicarboxylic acid and diol as main raw materials. Examples of the dicarboxylic acid component of the polyester include terephthalic acid, 2,6-naphthalenedicarboxylic acid, isophthalic acid, and 1,4-cyclohexanedicarboxylic acid. Examples of the diol component include ethylene glycol, butylene glycol, propylene glycol, Examples include tetramethylene glycol and 1,4-cyclohexanedimethanol. Polyester monofilaments synthesized by appropriately combining these dicarboxylic acid components and diol components can be used as appropriate. Of these, a polyester monofilament of polyethylene terephthalate in which 90 mol% or more of the dicarboxylic acid component is made of terephthalic acid and 90 mol% of the diol component is made of ethylene glycol is most preferable.

  To adopt high-strength materials such as polyester monofilaments, (1) By filling the filling material 17 or stacking the gabion-like members 11 to 14 in a step shape, shearing is applied even if the weight is applied. (2) Has high shape retention and wear resistance, and can be reused when the fishway structure A is removed and then re-installed. (3) High durability, long-term installation and removal There is an advantage that it is not deteriorated even when stored at the time, and (4) since it is bent to an appropriate degree by being formed in a mesh shape, processing and shape adjustment are easy.

  The filling material 17 is a member filled in the bowl-shaped body 16. The filling material 17 is not particularly limited as long as it is stone gravel or stone-like gravel, larger than the mesh member size, submerged with a specific gravity of 2 or more, and can be filled in the cage 16. Not. For example, stones such as cobbles, cobblestones, boulders, gravels, concrete waste, etc. can be used alone or in combination.

  For example, a large filling material 17 having a major axis of 30 cm or more is filled in a portion of the rod-like body 16 that is difficult to contact with water in the vicinity of the center, and a small filling agent 17 having a major axis of less than 30 cm is filled in a portion that is easily contacted by water in the peripheral part. May be filled. By placing the small filling material 17 in the peripheral part, it is possible to reduce the intrusion of water into the gap in the bowl 16, so that buoyancy is added to the large filling material 17 near the center. Thus, for example, the stability of the fishway structure A can be increased when the water is increased.

  The water-stagnation part 2 is a part that retains water that has flowed in from above. The water level height of the upper side B11 of the head B1 by disposing the stagnant parts 21, 22, 23, 24, 25 on the horizontal surface 15 of each step formed by laying the pedestal part 1, respectively. A stagnant region (a place where water stays) is continuously formed in a staircase pattern from the water level to the lower B12.

  The water-stagnation part 2 has a configuration in which a water-impervious bag-like body 27 formed to be open at the top is attached to the inside of a bowl-like body 26 that is formed from a net-like member so as to be open at the top.

  The saddle-like body 26 forming the water-stagnation part 2 is a frame part for mounting the water-impervious bag-like body 27 on the inner side, and is formed in a net-like member so as to be open upward. The assembly procedure of the bowl-shaped body 26 is not particularly limited. For example, as in the above, for example, a plurality of panel-like net members constituting the bottom surface and each side surface are fastened with a string-like member as they are or while being bent. Thus, it can be formed. As the mesh member forming the bowl-like body 26, those having the same thickness and material as those of the mesh member forming the bowl-like body 16 can be widely used.

  The water-impervious bag 27 is a part for storing water flowing in from the upstream side. In principle, the water-impervious bag 27 is mounted in a state where the outer side of the bag is substantially in contact with the bottom surface and all side surfaces of the bowl-shaped body 26.

  The water-impervious bag 27 may be any member that has a bag-like form, is not easily damaged, and can store water therein for a certain period of time. Not.

  As the water-impervious bag 27, for example, a nonwoven fabric mat formed in a bag shape can be suitably used. As the nonwoven fabric mat, known ones can be widely used. For example, a nonwoven fabric mat having a thickness of 0.5 to 30.0 mm is most preferable. Employing the nonwoven mat has the following advantages. (1) The non-woven mat is light when not containing water. Therefore, transportation and installation can be performed with low labor. (2) On the other hand, it has high moisture absorption and water retention, and its weight increases significantly when it contains water. (3) Since the flexibility is high and the weight increases due to water absorption, when water is stored inside, it is pressed against the wall side of the rod-like body by its weight, and is applied to the bottom surface and the front side surface of the rod-like body 26. Abuts well. (4) When the nonwoven fabric mat is saturated with water, the water permeability is reduced and water impermeability is achieved. (5) Since the fine suspension is clogged in the nonwoven fabric, the water barrier property is enhanced. (6) Hard to tear and highly durable.

In the water-stagnation part 2, the water-impervious bag 27 may be attached after a small number of gravel or a gravel-like filling material is filled in the bowl-like body 26. When the water-impervious bag 27 is pressed against the wall side of the bowl-like body 26 due to the weight increase due to water absorption, the filling material is sandwiched between the bowl-like body 26 and the water-impervious bag-like body 27, A shape having unevenness close to nature can be reproduced in the water part 2 (water-impervious bag 27). This makes it easier for migratory fish to rest in the water-stagnation part 2 and to hide themselves from natural enemies such as birds, so that the migratory fish can be promoted.

  As shown in FIGS. 1 and 2, the fishway structure A is formed by stacking the gabion-like members 11, 12, 13, and 14 in a step shape to form the pedestal portion 1, and further laying the pedestal portion 1. The stagnant portions 2 are formed on the horizontal surfaces 15 of the respective steps.

  In FIG. 1 and FIG. 2, the lowest stage is formed by the gabion-like member 14 and the water-stagnation part 25 and is installed on the riverbed G. The second stage is formed by the gabion-like member 13 and the water-stagnation part 24, the third stage is formed by the gabion-like member 12 and the water-stagnation part 23, and the fourth stage is formed by the gabion-like member 11 and the water-stagnation part 22. In the uppermost stage, the water-stagnation part 21 is arranged.

  In other words, the stagnant part and the gabion-like member form a single step (in FIGS. 1 and 2, reference numerals 25 and 14, 24 and 13, 23 and 12, 22 and 11 respectively), and the stagnant part is a staircase. The next stage stagnant part and the gabion-like member are stacked on the gabion-like member at each stage, and the uppermost gabion-like one is at the lowermost stage. The fishway structure A according to the present invention is formed by disposing the water-stagnation part on the member. The uppermost water-stagnation part 21 is arranged in a state where one of the side wall surfaces is substantially in contact with the head part B1 so that the water flow W0 on the upper side B12 of the head part B1 flows.

  The gabion-like members 11, 12, 13, and 14 may be formed of one member as shown in FIG. 1 or 2, for example, and each step may be formed of two or more gabion-like members. Further, the same step of the gabion-like member and the water-stagnation part (for example, 14 and 25, 13 and 24, 12 and 23) may be integrally formed. In that case, for example, after the gutter-like body 16 forming the gabion-like members 11, 12, 13, and 14 and the gutter-like body 26 forming the stagnant portion are integrally formed with the same net-like member, the net-like member for partitioning is formed. The two parts are divided into two areas, one side is filled with the filling material 17 and the upper surface is substantially closed, and the other side is fitted with a water-impervious bag 27 to form one step of the water-stagnation part and the gabion-like member. it can. When forming those shapes with a plurality of mesh members, for example, each panel-like mesh member may be fastened with a known string-like member or the like. In addition, the gabion-like members 11, 12, 13, 14 and the stagnant part 2 are formed respectively, and the gabion-like members 14, 13, 12, 11 are stacked in order, and the gabion-like members 11, 12, 13, 14 are Each stagnant portion 2 may be formed by fastening with a known string-like member or the like. In that case, the water-stagnation part 2 can be easily separated from the gabion-like members 11, 12, 13, and 14, so that the water-spilling part 2 is removed in advance when, for example, an increase in the amount of water is expected, such as flooding. Therefore, it is possible to prevent an excessive water pressure from being applied to the fishway structure A, thereby enabling a more stable installation of the fishway structure A.

  The shape of the stagnant part 2 is not particularly limited as long as it can be continuously arranged in a stepped manner from the water level height on the upper side B11 to the water level height on the lower side B12 of the head part B1. For example, a columnar shape having a bottom surface or a top surface having a substantially square shape, a substantially triangular shape, or a substantially sector shape can be employed. The shape of the gabion-like members 11 to 14 is appropriately set based on the shape of the stagnant part 2 from the uppermost step to the uppermost step so that the stagnant part 2 can be arranged in steps when stacked. To do. The shape and size of the gabion-like members 11 to 14 in each step do not need to be the same, and in principle, the bottom or top surface area is formed largest in the lowest step, and the bottom or It is formed so that the area of the upper surface is appropriately reduced.

  In the fishway structure A shown in FIGS. 1 and 2, a part (reference numeral 29) of the entire circumference of the upper edge 28 of the water-stagnation part 2 is recessed below the other upper edge part, thereby You may have the structure by which the overflow direction (code | symbol W1-W5) of the water from the part 2 was prescribed | regulated. By forming this concave portion 29 in each water catching portion 2, in principle, the water overflowing from the water catching portion 2 can overflow from the portion of the concave portion 29. By denting a part of the side wall surface of the part 2, the water flow W can be surely flowed into an assumed place such as the water-stagnation part 2 below. Therefore, by forming the recess 29 in each of the water-stagnation parts 21 to 25, it is possible to form a continuous water flow in a stepped manner from the water level height of the upper side B11 of the head part B1 to the water level height of the lower side B12. it can.

  The concave portion 29 is formed by, for example, denting the upper edge of the side wall surface in the direction of the lower water-stagnation part in the water-stagnation parts 21 to 24 other than the lowermost stage, It is formed by denting the upper edge of the side wall surface in the direction in which water is finally discharged (in principle, the downstream direction).

  As the means for forming the concave portion 29, known ones can be widely adopted, and are not particularly limited. However, in the present invention, the side wall surface of the water-stagnation part 2 is formed of a net-like member. By pulling down with a member or the like and fixing the string-like member in that state, it is possible to easily form a recessed portion up to about 60% of the height of the side wall surface. At this time, the concave portion 29 may be surely covered with the water-impervious bag 27 and formed so that the water level can be finely adjusted according to the depression of the water-impervious bag 27.

  In addition, the water-stagnation part 2 is not limited to a narrow case when the upper surface is disposed so as to be substantially horizontal, and may be disposed at an inclination, for example. In that case, for example, by changing the method of laying the filling material 17 in the gabion-like member (symbol 11, 12, 13 or 14) immediately below the water-stagnation part 2, the stagnation is appropriately performed according to the purpose and application. The water part 2 can be disposed to be inclined. In that case, for example, by inclining the stagnant part 2 in the direction of the one stagnant water part or finally in the direction of discharging water, Since the dead weight is loaded in the direction of the river crossing structure B by inclining the stagnation part 2 in the direction of the river crossing structure B to be installed, the fishway structure A is further stabilized. it can.

  In the fishway structure A according to the present invention, the height of the side wall surface of the water-stagnation part 2 may be set to a height at which the target fish can jump. By setting the height of the side wall surface of the water-stagnation part 2, that is, each step formed between the water-stagnation parts to a height at which the target fish can jump, the target fish can be Flying while resting at 25, it is possible to climb each stagnant part 21-2 step by step, and finally reach the upper side B11 of the head B1.

  The jumpable height of the target fish varies depending on the fish species, for example, by setting the height of the side wall surface of the water-stagnation part 2, that is, the step between the water-spilling parts to about 20 to 40 cm, Migratory fish such as salmon, ayu and cherry salmon will be able to go up.

  In the fishway structure A in FIG. 1, sandwiching bars 3, 3, and 3 are respectively sandwiched between the stacked gabion-like members 11, 12, 13, and 14, and the sandwiched bars 3, 3.Each end of 3 and 3 protrudes to the side of the pedestal 1 and each end of the connecting bar 4 spanned between the protruding ends of the sandwich bars 3, 3, 3. It has a configuration reinforced by fixing.

  The fishway structure A is simplified by fixing the sandwich bars 3, 3, and 3 with the weight of the gabion-like member 11, and by fixing the sandwich bars 3, 3, and 3 with connecting bars 4. Can be reinforced with low labor and low cost. As a result, even when excessive water pressure is applied to the fishway structure A, such as floods, the overall shape can be maintained more firmly, and the fishway structure A can be unexpectedly collapsed or washed away. Can be prevented.

  The material of the sandwich bar 3 is not particularly limited as long as it is a bar that can be sandwiched at the boundary between the gabion-like members 11, 12, 13, and 14. For example, wood such as logs may be used.

  The material of the connecting rod 4 is not particularly limited as long as it is a rod that can be fixed between the protruding end portions of the sandwiched rod members 3, 3, and 3 by fixing the end portions. For example, wood such as logs may be used. As a means for fastening the sandwiching bar 3 to the connecting bar 4, a known member such as a string-like member can be widely used.

  The fish guiding means 5 is a guiding member for allowing the fish to enter the fishway structure A. In general, migratory fish try to swim in the direction of water flow when going up. By utilizing this property, the water flow W5 that has fallen from the lowermost water-stagnation part 25 is guided by the fish guidance means 5, and the dispersion and attenuation of the momentum of the water flow is suppressed, and the water flow is maintained. Can be encouraged to swim toward the fishway structure A, and the discovery of the fishway and entry into the fishway structure A can be promoted.

  The fish guiding means 5 may be any means as long as it can induce the water flow from the lowermost water-stagnation part 25, and a wide variety of known ones can be used, and is not limited to a narrow one.

  For example, a gabion-like member filled with stone gravel or a gravel-like filling material in a substantially columnar rod-like body whose entire surface is substantially blocked with a net member may be used. . As the mesh member and the filling material, the same ones as described above can be used. For the water-impervious sheet member, the same material as the water-impervious bag 27 such as a nonwoven fabric mat can be used. For example, using the nonwoven fabric mat for the water-impervious sheet member has the following advantages similar to the above. (1) The non-woven mat is light when not containing water. Therefore, transportation and installation can be performed with low labor. (2) On the other hand, it has high moisture absorption and water retention, and its weight greatly increases when it contains water. (3) High flexibility and increased weight due to water absorption, so that it is easy to adhere to the gabion-like member and can be coated well. (4) When water is saturated in the non-woven mat, the water permeability is reduced and water impermeability is obtained, so that buoyancy against the filling material in the gabion member can be hardly generated. (5) Since the fine suspension is clogged in the nonwoven fabric, the water shielding property can be enhanced. (6) Hard to tear and highly durable.

  The installation process of the fishway structure A according to the present invention can be performed based on a known method and is not particularly limited. Since this fishway structure A can be installed easily and in a short period of time by assembling relatively lightweight members, it is not necessary to completely shut off the water flow W at the installation site, and the water flow at the installation site Construction with reduced W is possible. The same applies to the removal of the fishway structure A.

  For example, a bowl-like body 16 that forms the lowermost gabion-like member 14 is installed at an installation location facing the head B1 formed in the water flow, and the upper surface is substantially closed by filling with the filling material 17 and sandwiched. After placing the rod 3, the bowl 16 forming the next stage gabion-like member 13 is placed on the bottom gabion-like member 14, and the filling material 17 is packed to close the upper surface substantially. The pedestal 1 is formed by repeating the operation. Then, the side and the top of each gabion-like member 14, 13, 12, 11 are arranged so that the stagnant portion 2 is arranged in a stepped manner from the water level height of the upper side B11 of the head B1 to the water level height of the lower side B12. The fishway structure A is formed by arranging and fixing the water-stagnation part 2 on the upper surface of the upper gabion-like member 11. On both sides of the fishway structure A, the connecting members 4 are stretched between the protruding end portions of the sandwiching rods 3, 3, and 3 to fix and reinforce each end portion. When removing fishway structure A, work in reverse order. These operations can be performed by human power or machine.

  Thus, the fishway structure A according to the present invention can be removed and reconstructed relatively easily, with low labor and at low cost. Therefore, for example, it is expected that the target fish will be removed and stored at a time when it does not run up, and reconstructed only before and after the run up, or the amount of water will increase significantly due to typhoons and floods. In such a case, the fishway structure A may be removed once, and the fishway structure A may be reconstructed after the increase in the amount of water is alleviated. Further, for example, when it is predicted that the amount of water will increase significantly, the stagnant portion 2 may be removed from the gabion-like member 14. Thereby, the risk of collapse of the fishway structure A can be reduced and safety can be increased while reducing the removal work.

  FIG. 3 is a schematic external perspective view showing an example of a folded fishway structure according to the present invention.

  The fishway structure A ′ in FIG. 3 is installed in the head portion B1 formed in the water flow W in the X1 direction by the river crossing structure B, as in FIG. 21, 22, 23), and the pedestal portion 1 is a gabion-like member 11 in which a gravel or a gravel-like filling material 17 is filled in a rod-like body 16 whose entire surface is substantially closed by a net-like member. , 12 are stacked in a staircase shape, and each stagnant part 2 is fitted with a water-impervious bag-like body 27 formed in the upper part of the inside of the bowl-like body 26 formed in the upper part of the net-like member. By forming the stagnant part 2 on the horizontal plane of each stage of the stage formed by laying the pedestal part 1, it is possible to retain the water flowing in from the upper side. From the water level height of the upper side B11 of B1 to the water level height of the lower side B12, the stagnant part 2 is continuously formed in a step shape.

  In FIG. 3, the stagnant part 2 is formed in a columnar shape with a substantially square bottom or top surface, similar to FIG. 1 and the like, and the shape of the gabion-like member 12 is from the top to the top. The shape of the gabion-like member 11 is based on the shape of the uppermost stagnant part 21 so that the stagnant part 2 can be arranged in a staircase shape when stacked. Is set to

  In the fishway structure A ′ shown in FIG. 3, the water-stagnation parts 21, 22, and 23 are arranged in an approximately S shape when viewed from above in a folded shape. The uppermost water-stagnation part 21 is arranged in a state where one of the side wall surfaces is substantially in contact with the head part B1 so that the water flow W0 on the upper side B12 of the head part B1 flows. And, the concave portion 29 is formed by denting the upper edge of the side wall surface in the direction of the lower water stagnation part in the water stagnation parts 21 and 22 other than the lowest stage, and in the water stagnation part 23 in the lowermost stage, It is formed by denting the upper edge of the side wall surface in the direction of finally discharging water. As a result, a continuous water flow (W0 to W3) is formed from the water level height on the upper side B11 to the water level height on the lower side B12 of the head B1.

  Even in this configuration, the target fish enters between the fish guidance means 5, 5 and flies while resting at each water-stagnation part 21-23, and climbs one step at a time in the order of the water-spilling parts 23, 22, 21. Finally, it can reach the upper side B11 of the head portion B1.

  FIG. 4 is a schematic external perspective view showing an example of a triangular fishway structure according to the present invention.

  The fishway structure A ”in FIG. 4 is also installed in the head part B1 formed in the water flow W in the X1 direction by the river crossing structure B, as in FIG. 1, etc., and the pedestal part 1 and the four stagnant parts 2 ( 21, 22, 23, 24), and the pedestal portion 1 has a gabion-like shape in which a rod-like body 16 substantially entirely closed with a net-like member is filled with stone gravel or a gravel-like filling material 17 Formed by stacking the members 11, 12, 13 in a stepped manner, each stagnant portion 2 is formed in a water-impervious bag shape formed in an open top inside a bowl-like body 26 formed in an open top with a mesh member. By installing the body 27, it is formed so that the water flowing in from the upper side can be retained, and the stagnant parts 2 are respectively arranged on the horizontal planes of the steps formed by laying the pedestal part 1. Thus, the stagnant portion 2 is continuously formed in a step shape from the water level height on the upper side B11 to the water level height on the lower side B12.

  In FIG. 4, the stagnant portion 2 is formed in a columnar shape with a substantially triangular bottom or top surface, and the shape of the gabion-like members 12 and 13 is stagnant from the upper level to the uppermost level. Based on the shape of the parts 23, 22, and 21, the shape of the gabion-like member 11 is set based on the shape of the uppermost stagnant part 21 so that the stagnant part 2 can be arranged stepwise when stacked. Has been.

  In the fishway structure A ”in FIG. 4, the water-stagnation parts 21, 22, 23, 24 are arranged in a substantially S shape in a triangular shape when viewed from above. One of the side wall surfaces is arranged in contact with the head portion B1 so that the water flow W0 of the upper side B12 flows in. The concave portion 29 is one in the stagnant portions 21, 22, and 23 other than the lowest level. Formed by denting the upper edge of the side wall surface in the direction of the lower water stagnation part, and forming the upper part of the side wall surface in the direction of finally releasing water at the lower water stagnation part 23. As a result, a continuous water flow (W0 to W4) is formed in a folded shape from the water level height of the upper side B11 of the head B1 to the water level height of the lower side B12. When the shape of the bottom surface or the top surface of the portion 2 is formed in a substantially fan-shaped columnar body shape, the shape can be substantially the same as the fishway structure A ″ in FIG.

  Also in this configuration, the target fish enters between the fish guidance means 5 and 5 and flies while resting in each water-stagnation part 21 to 24, and one step at a time in the order of the water-spilling parts 24, 23, 22, and 21. It is possible to climb up to finally reach the upper side B11 of the head B1.

  FIG. 5 is an external perspective schematic view showing an example of fish run-up promotion means according to the present invention.

  For example, in the water channel in which the water flow direction X1 is fixed by fixing the side surface C1 and the water bottom G with concrete or the like, as shown in the concrete three-sided water channel C shown in FIG. 5, the same member as the fish guiding means 5, for example, A gabion-like member 11 ′ in which a substantially columnar rod-shaped body whose entire surface is substantially closed with a net-like member is filled with a gravel or a gravel-like filling material, and the rod-shaped body is covered with a water shielding sheet member, The fish run-up promotion means A ′ ″ arranged across the river in the water channel at a predetermined interval also effectively promotes the run-up and movement of migratory fish and coastal creatures.

  By arranging a plurality of gabion-like members 11 ′ in the water channel C, the water flow (W1 to W3) can collide with the gabion-like member 11 ′ and decelerate, so that the flow can be moderated. Moreover, the water-stagnation part 2 can be formed on the upstream side of each gabion-like member 11 '. The gabion-like member 1 'has a height that allows migratory fish to jump over. Therefore, by disposing a plurality of gabion-like members 1 ′ in the water channel, it is possible to create an environment in which migratory fish can easily go upstream. In addition, aquatic aquatic organisms such as eel, goby, crab and shrimp can move up and move over the gabion-like member 1 '.

  Therefore, for example, in each location such as a river, the above-mentioned fishway structures A, A ', A ", etc. are applied to a place where a river crossing structure is built, etc. By installing the fish run-up promotion means A ′ ″, the entire river can be improved to an environment in which migratory fish can easily go up, and an environment in which other aquatic organisms can live easily can be created.

The external appearance schematic perspective view which shows the example of the fishway structure which concerns on this invention. The water flow direction cross-sectional schematic diagram which shows the example of the fishway structure which concerns on this invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic external perspective view showing an example of a folded fishway structure according to the present invention. The external appearance perspective schematic diagram which shows the example of the fishway structure of the triangular form which concerns on this invention. The external appearance schematic diagram which shows the example of the fish run-up promotion means which concerns on this invention.

1 pedestal
11, 12, 13, 14 Gabion-like member
15 Horizontal surface of each step formed by laying pedestal 1
16 A bowl-shaped body forming a gabion-like member 11, 12, 13, 14
17 Filling material
2 (21, 22, 23, 24, 25)
26 A rod-shaped body that forms a stagnant part
27 Impermeable bag
28 Upper edge of stagnant part 2
29 Recessed part 2
3 sandwich bar
4 Connecting bar
5 Fish guidance means
A, A ', A ”Fishway structure
A '''Means for promoting fish
B River crossing structure
B1 head
B11 Upper side of the head
B12 Below the head
C Three-sided waterway
G River bottom
X1 Water flow direction
W water current
W0 Water flowing into the uppermost aquifer 21
W1 to W5

Claims (4)

A fishway structure that is installed at the head part formed in the water stream,
It has a pedestal part and a plurality of stagnant parts,
The pedestal portion is formed by stacking gabion-like members filled with stone gravel or a gravel-like filling material in a staircase body, the entire surface of which is substantially blocked with a net-like member,
The water stagnation part is formed so that water flowing in from the upper side can be retained by mounting a water-impervious bag-like body formed in the upper part of the inside of the bowl-like body formed in the upper part of the mesh member. And
A stagnant region from the upper water level height of the head portion to the lower water level height by disposing the stagnant portion on the horizontal surface of each step formed by laying the pedestal portion. Is a fishway structure formed continuously in a staircase pattern.   2. The fishway structure according to claim 1, wherein the height of the side wall surface of the stagnant portion is set to a height at which the target fish can jump.   2. The overflow direction of water from the water stagnation part is defined by denting a part of the entire circumference of the upper edge of the water stagnation part below the other upper edge part. 2. The fishway structure according to item 2.   Each sandwich bar is sandwiched between the stacked gabion-like members, and each end of each sandwich bar is projected to the side of the pedestal, respectively. The fishway structure according to any one of claims 1 to 3, wherein the fishway structure is reinforced by fixing each end portion to a connecting rod that extends between the projecting end portions.

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