JPH0813449A - Fish block - Google Patents

Abstract

PURPOSE:To provide a fish block having such an effect as aquatic creatures can escape out of the fish block, exchangeability of water is favorable, dirts and dead leaves flow out with ease naturally, a revetment, head-making construction and a scenic view of a fishway is brought close to the nature, and appropriate positions to hook a creel, a rope, and hands can be provided. CONSTITUTION:A fish block 1 is provided with a bottom base 2 on which a number of stones are scattered on the upper face, a vertical wall 3 erected at the rear edge of the bottom base, a support wall 4 projected to the front side from the upper end of the vertical wall 3, a plurality of protrusions at the front edge of the bottom base 2 to keep stones, and a plurality of clearance paths 6 formed between respective protrusions keeping stones. The protrusion 5 keeping stones has a cylindrical columnar form and the surface thereof is provided with the shape and pattern of natural trees.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a block used for revetment of waterways such as rivers and artificial canals, head works, and fishways.
In particular, it relates to a fish nest block suitable for inhabiting aquatic organisms such as fish, shellfish, and crabs.

[0002]

2. Description of the Related Art Japanese Utility Model Laid-Open No. 3-79325 discloses a fish depression block used for heading a river. As shown in FIG. 16, the fish depression block 61 is connected to the base portion 62 having a flat rectangular shape, the left vertical wall 63 standing at the left end of the base portion 62, and the upper end of the left vertical wall 63. It is composed of an upper horizontal wall 64 provided and a right vertical wall 65 standing at the right end of the base 62, and the height of the right vertical wall 65 is lower than that of the left vertical wall 63. There is. Then, as shown in FIG. 17, a plurality of fish depression blocks 61 are
They are installed at intervals in the flow direction of the river. The individual fish depression blocks 61 are installed so that the left vertical wall 63 and the right vertical wall 65 are substantially buried in a riverbed 69 having a head, and a fish depression 66 is formed between the vertical walls 63 and 65. It

As described above, the fish depression block 61 is formed on the riverbed 6.
Since it is buried in 9, the left vertical wall 6 is prevented so that the mud of the riverbed 69 does not enter the fish depression 66 and fill the fish depression 66.
3 and the right vertical wall 65 had to be "walls" that were impermeable to mud.

[0004]

However, the conventional fish depression block 61 has the following problems. As described above, the left vertical wall 63 and the right vertical wall 65 are “walls”, and since there is no escape route for aquatic organisms in any of them, when the water flow rate of the river decreases significantly, It will be trapped in the fish depression 66. Since no water passage is provided in any of the left vertical wall 63 and the right vertical wall 65, it is disadvantageous in the exchangeability of water, which is important for aquatic organisms. Dust, dead grass, and the like that have flowed into the fish nest block 71 are blocked by the right vertical wall 65 and easily collect in the fish depression 66.

Therefore, as shown in FIG. 18, the applicant has previously made a bottom plate 72, a vertical wall 73 standing on the rear edge of the bottom plate 72 and extending in the left-right direction, and an upper end of the vertical wall 73. A support wall 74 projecting from the front side of the bottom plate 72, and a receiving wall 75 standing on the front edge of the bottom plate 72 and extending in the left-right direction. A part of the receiving wall 75 is an escape path 76 for aquatic life. A fish nest block 71 (Example) in which the fish nest block is formed is proposed, and further, a seawall, a head construction, and a fishway using the fish nest block 71 are proposed (JP-A-5-179629 and JP-A-5-179629).
306508, Japanese Patent Laid-Open No. 5-306511).

According to this fish nest block 71, the above-mentioned problem can be alleviated because the escape path 76 is formed in a part of the receiving wall 75. However, there is still room for improvement regarding this problem, and the problem has not been solved. Moreover, the following problems remained. The seawall, head drop and fishway landscapes should be as close to nature as possible. Therefore, the fish nest block 71
Although the surface of the was provided with irregularities due to a pattern, it was still insufficient. There were no suitable parts for pedestrians in the waterways to hang ropes or ropes, or for the victims to hold their hands in times of water shortage.

Therefore, the object of the present invention is not only to hold stones on the upper surface of the bottom plate to form fish nests suitable for inhabiting aquatic organisms such as fish, shellfish and crabs, but also to obtain the following effects. To provide fish nest blocks. Aquatic organisms can escape from fish nests when the flow of water in a river is significantly reduced. It is advantageous for water exchange, which is important for aquatic organisms, can form fish nests rich in oxygen and nutrients, and is also suitable for spawning. Dust, dead grass, etc. that have flowed into the fish nest block easily flow off naturally and do not easily accumulate in the fish nest. The scenery of seawalls, head works and fishways can be made closer to nature. You can add appropriate parts for pedestrians in the waterway to hang ropes and ropes, and for the victims to hold their hands in case of water shortage,
It can contribute to the improvement of convenience and safety.

[0008]

In order to achieve the above object, a fish nest block of the present invention comprises a bottom plate on which a large number of stones are scattered on an upper surface, and a vertical wall erected at a rear edge of the bottom plate. A support wall protruding forward from the upper end of the vertical wall, a plurality of stone stopper protrusions protruding from the front edge of the bottom plate, and a plurality of stone stopper protrusions formed between the plurality of stone stopper protrusions. And a gap passage.

Further, another fish nest block of the present invention is a vertical wall for connecting a plurality of stages of bottom plates arranged at intervals in the vertical direction and having a large number of stones sprinkled on each upper surface, and a rear edge portion of each of the bottom plates. And a plurality of stone stopper projections protruding from the front edge of each of the bottom plates, and a plurality of gap passages formed between the plurality of stone stopper projections.

In each of the fish nest blocks described above, examples of the shape of the "stone stopper projection" include a cylindrical shape, a prismatic shape, a conical shape, a pyramidal shape, a trapezoidal shape, an indeterminate shape, etc. It is preferable to add the shape, pattern or color of natural objects such as stones. The stone stopper projection may be formed integrally with the bottom plate, or may be formed separately from the bottom plate and then attached to the bottom plate. The width of the "gap passage" is
It is preferably larger than the width of aquatic organisms and smaller than the diameter of the main stones wound on the upper surface of the bottom plate.

Further, a blocking wall extending in the front-rear direction is erected on a part of the bottom plate (for example, the left edge part, the right edge part or the middle part), and a passage is formed in a part of the blocking wall, or the bottom plate is formed. It is preferable that a plurality of blocking projections be juxtaposed in the front-rear direction in a part of the above so as to form a plurality of passages between the plurality of blocking projections.
These blocking walls or blocking projections may be formed integrally with the bottom plate, or may be formed separately from the bottom plate and then attached to the bottom plate.

Further, it is preferable to make unevenness on at least a part of the surface, and the following can be exemplified as the means. A plurality of convex portions or concave portions are integrally formed on the upper surface of the bottom plate. Mount multiple protrusions on the top surface of the bottom plate. A part of the bottom plate, a stone stop protrusion, a stop wall, a stop protrusion, or an attachment to these is formed of uneven water-permeable concrete. Part of the bottom plate, stone stopper protrusions, stopper walls, stopper protrusions, etc. are less loaded than vertical walls and support walls, so
Even if it is made of water-permeable concrete, there is no problem in strength.
When the bottom plate is made of water-permeable concrete, it is preferable to use reinforcing rods made of carbon, synthetic resin, stainless steel or the like that do not rust.

By forming the unevenness in this way, the surface area of the fish nest increases, and the state of the natural riverbed is approached. Therefore,
Even if the amount of stones scattered on the upper surface of the bottom plate is reduced, fish nests suitable for aquatic life are formed. Further, since it is hard to slip when walking in a waterway, it is possible to prevent a slip accident. Further, if the water-permeable concrete having irregularities is used as described above, the supply of oxygen and nutrients is improved due to its porosity.

[0014]

In the fish nest block according to the first aspect, the blocks can be stacked to construct a seawall, a drop construction, or can be arranged in a line to construct a fishway. When stacking, the bottom plate of the upper fish nest block can be placed and supported on the upper surfaces of the vertical wall and the support wall of the lower fish nest block. And
By changing the relative position of the upper and lower fish nest blocks in the front-rear direction, it is possible to deal with revetments with different slopes, head drop construction, etc.
Further, the fish nest block according to claim 2 can construct a revetment, a drop construction, etc. just by lining them.

Furthermore, on the upper surface of the bottom plate of the fish nest block according to claim 1 or 2, stones such as chestnut stones, cobblestones (gravel may be added) are evenly or unevenly scattered, fish, shellfish. It forms a fish nest that is close to the natural riverbed and is suitable for aquatic life such as crabs. If you combine chess stones and cobblestones and scatter them unevenly, the fish nest will change, and if you add charcoal, bamboo chips, cedar bark, husks, volcanic rocks, etc., it will help purify the water. A plurality of stone stopper projections protruding from the front edge of the bottom plate prevent the scattered stones from spilling forward, thus stabilizing the environment of the fish nest.

Further, since direct sunlight is appropriately applied to the fish nest from above the front edge of the bottom plate, the water temperature is appropriately increased, and an environment favorable for growth of aquatic plants such as aquatic plants and algae is formed. In addition, since the shade is appropriately formed below the support wall, a favorable environment for resting aquatic organisms is formed.

Further, the fish nest block according to claim 1 or 2 is different from the conventional example shown in FIGS.
Since the front edge portion of the bottom plate is provided with the plurality of stone stopper projections and the plurality of gap passages between them, the following operation is achieved. When the flow of water in the river is significantly reduced, aquatic organisms pass through one of the multiple gap passages without hesitation,
You can surely escape from the fish nest. Since water can pass through the multiple gap passages well, it is advantageous in exchanging water, which is important for aquatic organisms, can form fish nests rich in oxygen and nutrients, and is also suitable for spawning. Dust, dead grass, etc. that have flowed into the fish nest block easily flow off naturally through any of the multiple gap passages, and are less likely to accumulate in the fish nest. When viewed from a distance, the plurality of stone stop protrusions look like trees or stones, so that the scenery of the revetment, head drop and fishway can be made closer to nature. It is even better when the shape, pattern or color of a natural object such as natural wood or natural stone is provided on the surface of the stone stopper protrusion. The plurality of stone stopper projections are suitable parts for pedestrians in the waterway to hang ropes and ropes, and to be used by handicapped people in times of water shortage.

On the contrary, the fish nest block according to the first or the second aspect cannot be used by being buried in the riverbed as in the conventional example shown in FIGS. 16 and 17. At the front edge of the bottom plate,
Instead of "walls", there are multiple stone stopper projections and gap passages. If they are buried in the riverbed, mud in the riverbed will enter the fish nests through the gap passages and fill the fish nest. is there. That is, the plurality of stone stopper projections and the gap passages of the present invention and the "wall" of the conventional example are clearly different in the purpose, the configuration, and the effect.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A fish nest block according to a first embodiment of the present invention will be described below with reference to FIGS. This fish nest block 1 is molded into a shape as shown in FIG. 1 with concrete in which reinforcing reinforcing bars are embedded, and the thickness of each part is 200 mm. It should be noted that the dimensions of the respective parts listed below are examples, and can be changed as appropriate.

This fish nest block 1 is provided with a horizontal bottom plate 2 formed in the shape of a square plate, and its lateral length is 1980.
mm, the width in the front-back direction is 2000 mm. A vertical wall 3 extending in the left-right direction is integrally erected on the rear edge of the bottom plate 2,
The height from the bottom surface of the bottom plate is 1000 mm. Vertical wall 3
A support wall 4 horizontally projecting forward is integrally formed at the upper end of the, and the projecting width from the rear surface of the vertical wall is 1000 mm.

Eight stone stopper projections 5 are integrally formed on the front edge of the bottom plate 2, and seven gap passages 6 are formed between the eight stone stopper projections 5. Each stone stop protrusion 5
Has a columnar shape with a diameter of 150 mm and a height of 300 mm from the top surface of the bottom plate, and the surface of which has a shape and pattern of natural wood. The width of each gap passage 6 is 100 mm.

A blocking wall 7 extending in the front-rear direction is integrally provided upright in the middle of the left edge of the bottom plate 2. The width in the front-rear direction is 1100 mm shorter than that of the bottom plate 2, and the height from the top surface of the bottom plate 2 is smaller. It is 150 mm. Therefore, a left-right passage 8 is formed between both ends of the blocking wall 7 and the vertical wall 3 and the stone-blocking projection 5 at the left edge portion, and the opening width thereof is 250 mm.

A connecting hole 11 is formed in the bottom plate 2 and the supporting wall 4 for passing bolts connecting the fish nest blocks 1 when they are stacked vertically.

By using the fish nest block 1 of this embodiment, a seawall with a fish nest as shown in FIG. 2 can be constructed. That is, on the upper surface of the lower part of the slope 15 of the waterway
6 is laid, and abandoned concrete 17 is cast on the cobblestone 16. On the upper surface of this waste concrete 17, a plurality of fish nest blocks 1 are placed and lined up with the rear surface of the vertical wall 3 facing the slope 15, and on the upper surface of the bottom plate 2 there are rubble stones, cobblestones (adding gravel). The first stage is formed by combining the stones 18) of (good) and scattering them in an uneven shape. At the position shifted rearward from the first stage, the second stage is similarly formed, and the third stage is further formed. The water in the waterway flows in the lateral direction of the fish nest block 1.

Further, the fish nest block 1 of this embodiment can be used to construct a head structure with a fish nest as shown in FIG. That is, a step-like concrete base 14 is cast on the step of the riverbed 13 so as to extend in the transverse direction of the river. A plurality of fish nest blocks 1 are placed and lined on the upper surface of each step of the concrete base 14 with the rear surface of the vertical wall 3 facing the upstream side, and stones 18 are scattered on the upper surface of the bottom plate 2. A first stage, a second stage and a third stage are formed. The water in the water channel flows from the rear to the front of the fish nest block 1 as indicated by the arrow in FIG.

In the revetment or head drop construction, the fish nest blocks 1 in the second and third stages are sufficiently stabilized by their own weight.
However, by connecting these through bolts (not shown) in the connecting holes 11 of the upper bottom plate 2 and the lower support wall 4, it is possible to more reliably prevent the fish nest blocks 1 from shifting from each other.
Moreover, when riverbed scouring, ground subsidence, etc. occur, the fish nest blocks 1 can be connected in a flexible structure. Further, as shown in FIG. 3, it is preferable that anchor rebars 19 fixed to the fish nest block 1 and projecting rearward are embedded in the concrete base 14 to prevent the fish nest block 1 from shifting due to earth pressure and running water pressure. .

The fish nest block 1 in the upper stage may be stacked directly above the fish nest block 1 in the lower stage, or may be stacked in a staggered manner. In either case, the bolts can be connected. Further, by changing the relative positions of the upper and lower fish nest blocks 1 in the front-rear direction, the slope of the revetment or head drop can be easily changed.

Further, the fish nest block 1 of this embodiment can be used to construct a fish path with a fish nest as shown in FIG. That is, a plurality of fish nest blocks 1 face each other on the upper surface of a concrete foundation (not shown) cast on the riverbed in the field, and the vertical walls 3 of adjacent fish nest blocks 1 face each other. So that they are on opposite sides of each other,
Placed and lined up. Further, stones 18 are scattered on the upper surface of the bottom plate 2 of the fish nest block 1.

Since the fish nest block 1 of the present embodiment is constructed as described above, it has the following actions and effects.
First, since stones 18 such as chestnut stones and cobblestones are scattered on the upper surface of the bottom plate 2, fish nests suitable for inhabiting aquatic organisms such as fish, shellfish, and crabs are formed. The scattered stones 18 are prevented from spilling forward by a plurality of stone stopper projections 5 projecting from the front edge portion of the bottom plate 2, and are blocked by a blocking wall 7 standing on the left edge portion of the bottom plate 2. Since it is prevented from moving in the left-right direction, it is securely held on the upper surface of the bottom plate 2 and the environment of the fish nest is stabilized.

Further, since direct sunlight is appropriately applied to the fish nest from above the front edge of the bottom plate 2, the water temperature is appropriately increased,
Creates an environment favorable for the growth of aquatic plants such as aquatic plants and algae. Further, since the shade is appropriately formed below the support wall 4, an environment good for resting aquatic organisms is formed. Also, when water is drawn from the bottom plate 2, a bird can fall on the bottom plate 2 sprinkled with the stones 18 to play or drink water.

Further, since the bottom plate 2 is provided with a plurality of stone stopper projections 5 and a plurality of gap passages 6 therebetween, the following operation is achieved. When the flow rate of the river is significantly reduced, the aquatic organism can pass through any of the plurality of gap passages 6 (or the passage 8) without hesitation and reliably escape from the fish nest. Since the plurality of interstitial passages 6 also allow water to pass through satisfactorily, it is advantageous in exchanging water, which is important for aquatic organisms, can form fish nests rich in oxygen and nutrients, and is also suitable for spawning. Dust, dead grass, and the like that have flowed into the fish nest block 1 easily flow off naturally through any of the plurality of gap passages 6, and are less likely to accumulate in the fish nest. When viewed from a distance, the plurality of stone stopper projections 5 look like trees or stones, so that the scenery of the revetment, head drop construction and fishway can be made closer to nature. In particular, in this embodiment, since the shape and pattern of natural wood are attached to the surface of the stone stopper protrusion 5,
Even better. The plurality of stone stopper projections 5 serve as appropriate portions for pedestrians in the waterway to hang ropes and ropes, and to be held by handicapped people in times of water shortage, and can contribute to improvement in convenience and safety.

Next, in the fish nest blocks 1 of the second to seventh embodiments shown in FIGS. 5 to 10, the number and size of the stone stopper projections 5 projecting from the front edge of the bottom plate 2 are as follows. , Shape, position, etc.,
It differs from the first embodiment only in the number, width, etc. of the gap passages 6 formed between the stone stopper projections 5. Therefore, the same parts as those in the first embodiment are designated by the same reference numerals as those in the first embodiment to avoid repeating the description.
In the second embodiment of FIG. 5, six natural stone-shaped stone stopping protrusions 5 are integrally provided on the bottom plate 2, and five gap passages 6 are formed between the stone stopping protrusions 5. ing.
In the third embodiment shown in FIG. 6, six square pillar-shaped stone stopper projections 5 are integrally formed with the bottom plate 2, and five gap passages 6 are formed between the stone stopper projections 5. ing.
The width of each stone stopper projection 5 is 200 mm, the height from the top surface of the bottom plate is 300 mm, and the width of each gap passage 6 is 130 mm.
In the fourth embodiment of FIG. 7, five stone blocking protrusions 5 having a wave block shape are integrally formed with the bottom plate 2 and four gap passages 6 are formed between the stone retaining protrusions 5. ing. The width of each stone stopper projection 5 is 300 mm, the height from the top surface of the bottom plate is 300 mm, and the width of each gap passage 6 is 100 mm.

In the fifth embodiment of FIG. 8, five laterally laid columnar stone-stopping projections 5 are integrally provided on the bottom plate 2, and four gap passages 6 are provided between the stone-stopping projections 5. Are formed. The width of each stone stopper projection 5 is 300 mm, the height from the top surface of the bottom plate is 130 mm, and the width of each gap passage 6 is 1
It is 00 mm. In the sixth embodiment of FIG. 9, five double side-by-side columnar stone-blocking projections 5 are integrally provided on the bottom plate 2, and four gap passages 6 are provided between the stone-blocking projections 5. Has been formed. The width of each stone stopper projection 5 is 275
mm, height from the top surface of the bottom plate is 130 mm, each gap passage 6
Has a width of 125 mm. In the seventh embodiment of FIG. 10, eight substantially cylindrical stone-stopping projections 5 are integrally provided on the front end surface of the bottom plate 2 from the lower edge thereof, and the stone-stopping projections 5 are formed.
Seven gap passages 6 are formed between each other. The width of each stone stop projection 5 is 150 mm, and the height from the bottom edge of the bottom plate is 5
The width of each gap passage 6 is 100 mm.

Next, in the fish nest block 1 of the eighth to ninth embodiments shown in FIGS. 11 to 12, the stone stopper projections 5 are formed separately from the bottom plate 2 as described below, and then the bottom plate 2 is formed. It differs from the first embodiment only in that it is attached with bolts 12. Therefore, the same parts as those in the first embodiment are designated by the same reference numerals as those in the first embodiment to avoid repeating the description. In the eighth embodiment of FIG. 11, eight columnar stone stopper projections 5 and a connecting plate 9 for connecting their lower ends are integrally formed (separately from the bottom plate 2).
Is attached to the upper surface of the front edge of the bottom plate 2 with bolts 12.
In the ninth embodiment shown in FIG. 12, eight substantially cylindrical stone-stopping projections 5 and a connecting plate 9 for connecting the lower portions of their rear surfaces are integrally formed (separately from the bottom plate 2) and Board 9
Is attached to the front end surface of the bottom plate 2 with bolts 12.

According to the eighth to ninth embodiments, since the stone stopper projection 5 is formed separately from the bottom board 2, the stone stopper projection 5 does not exist on the bottom board 2 when the fish nest block 1 is formed. This simplifies the shape, and facilitates the design and demolding of the molding frame.

Next, the fish nest block 31 of the tenth embodiment shown in FIG. 13 will be described. This fish nest block 31 is formed by integrally forming three nests of fish nest blocks, and is provided with a three-tiered bottom plate 2 and an uppermost top plate 32 which are vertically arranged at a pitch of 1000 mm, and which are arranged in the left-right direction. Length is 200
The width in the front-rear direction is 0 mm and 1000 mm. The rear edges of the bottom plate 2 are connected by a tall vertical wall 3 formed integrally with them. Six rock stopper projections 5 are integrally formed on the front edge of each bottom plate 2 on the left and right, and gap passages 6 are formed between the rock stopper projections 5.

A support wall 33 for connecting and supporting the bottom board 2 (or the bottom board 2 and the top board 32) is integrally provided upright in the center of the fish nest block 31 in the left-right direction. A through hole 34 for aquatic life is formed therethrough. The support wall 33 may be omitted, or may be provided at one or both of the right end and the left end of the fish nest block 31, as shown by the chain line in the figure. A passage groove 36 is provided on the left end face of the bottom plate 2 of the second and third stages from the bottom so that aquatic organisms can move between the stages, and a fitting that fits the passage groove 36 shallowly on the right end face of the bottom plate 2. A mating protrusion 37 is provided. The number of steps of the bottom plate 2 can be changed appropriately.

By using the fish nest block 31 of the present embodiment, a seawall with a fish nest as shown in FIG. 14 can be constructed. That is, the concrete base 35 is placed on the lower upper surface of the slope 15 of the waterway, and the concrete base 3
The fish nest blocks 31 are placed and lined up on the upper surface of the vehicle 5 in an inclined state. Stones 18 are sprinkled on the upper surface of each base 2, but in this construction method, since the base 2 is inclined and the stones 18 are biased toward the rear, the upper surface of the base 2 should be an uneven surface and do not rely solely on the stones 18. Is preferred. This embodiment has substantially the same operation and effect as the first embodiment except that the steps are not displaced in the front-rear direction and the left-right direction.

Next, in the fish nest block 41 of the eleventh embodiment shown in FIG. 15, the point where the vertical wall 3 is inclined and the stone stopper projection 5 are provided.
Also, the connecting plate 9 is formed separately from the bottom plate 2, and is attached to the bottom plate 2 with the bolts 12, the support wall 33 is omitted, and the concavo-convex member 38 made of water-permeable concrete is formed on the upper surface of the bottom plate 2.
It is different from the tenth embodiment in that the bolts are attached by bolts 12. According to the present embodiment, since the vertical wall 3 corresponds to the slope of the slope, the bottom plate 2 is kept substantially horizontal, and stones are easily scattered. Moreover, the surface area of the fish nest is increased by the uneven member 38, and the state of the natural riverbed is approached. Therefore, even if the amount of stones sprinkled on the upper surface of the bottom plate 2 is reduced, fish nests suitable for aquatic life are formed. Also,
Since it is hard to slip when walking in a waterway, it is possible to prevent slipping accidents. In addition, the porosity of water-permeable concrete improves the supply of oxygen and nutrients.

The present invention is not limited to the configuration of the above-described embodiment, but may be embodied by appropriately changing it without departing from the spirit of the invention.

[0041]

EFFECTS OF THE INVENTION The fish nest block of the present invention is constituted as described above, and therefore, the stones are retained on the upper surface of the bottom plate so that fish, shellfish,
Not only can fish nests suitable for aquatic creatures such as crabs be formed, but the following effects can be obtained. Aquatic organisms can escape from fish nests when the flow of water in a river is significantly reduced. It is advantageous for water exchange, which is important for aquatic organisms, can form fish nests rich in oxygen and nutrients, and is also suitable for spawning. Dust, dead grass, etc. that have flowed into the fish nest block easily flow off naturally and do not easily accumulate in the fish nest. The scenery of seawalls, head works and fishways can be made closer to nature. You can add appropriate parts for pedestrians in the waterway to hang ropes and ropes, and for the victims to hold their hands in case of water shortage,
It can contribute to the improvement of convenience and safety.

[Brief description of drawings]

FIG. 1 is a perspective view of a fish nest block according to a first embodiment of the present invention.

FIG. 2 is a perspective view of a seawall with a fish nest constructed by the fish nest block.

FIG. 3 is a cross-sectional view of a drop structure with a fish nest constructed by the fish nest block.

FIG. 4 is a cross-sectional view of a fishway with a fish nest constructed by the fish nest block.

FIG. 5 is a perspective view of a fish nest block according to a second embodiment.

FIG. 6 is a perspective view of a fish nest block according to a third embodiment.

FIG. 7 is a perspective view of a fish nest block according to a fourth embodiment.

FIG. 8 is a perspective view of a fish nest block according to a fifth embodiment.

FIG. 9 is a perspective view of a fish nest block according to a sixth embodiment.

FIG. 10 is a perspective view of a fish nest block according to a seventh embodiment.

FIG. 11 is a perspective view of a fish nest block of an eighth embodiment.

FIG. 12 is a perspective view of a fish nest block according to a ninth embodiment.

FIG. 13 is a perspective view of a fish nest block according to a tenth embodiment.

FIG. 14 is a cross-sectional view of a seawall with a fish nest constructed by the fish nest block.

FIG. 15 is a perspective view of a fish nest block according to an eleventh embodiment.

FIG. 16 is a perspective view of a conventional fish depression block.

FIG. 17 is a cross-sectional view of a head drop structure using the fish depression block.

FIG. 18 is a perspective view of another conventional fish nest block.

[Explanation of symbols]

 1 Fish nest block 2 Bottom plate 3 Vertical wall 4 Support wall 5 Stone stop projection 6 Gap passage 31 Fish nest block 41 Fish nest block

Claims (2)

[Claims] 1. A bottom plate on which a large number of stones are scattered on an upper surface, a vertical wall erected at a rear edge portion of the bottom plate, a support wall protruding forward from an upper end of the vertical wall, and a bottom plate of the bottom plate. A fish nest block comprising a plurality of stone stopping protrusions protruding from a front edge portion and a plurality of gap passages formed between the plurality of stone stopping protrusions. 2. A plurality of tiers of bottom plates, which are vertically arranged at intervals and in which a large number of stones are sprinkled on each upper surface, vertical walls connecting rear edges of the bottom plates, and front edges of the bottom plates. A fish nest block comprising a plurality of protruding stone stopper protrusions and a plurality of gap passages formed between the plurality of stone stopper protrusions.