JPH0925621A - Block for artificial fish reef - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain a stable function as blocks for erosion and sedimental control, bulkhead, revetment and a fish reef by a method wherein blocks, insides of which are hollowed, are arrayed, bases, in which flow paths formed to each peripheral wall are matched, and covers are installed while holes are bored to the covers and the covers are communicated with the bases. SOLUTION: The insides of bases 1 are formed in hexagonal-shaped hollow sections 1a. The projections of trapezoidal covers 2 are fitted and connected into the engaging holes of the bases 1. Flow path holes 2c are bored to each of inclined planes 2b, and openings 2d are formed at upper ends. Each side of the bases 1 is abutted and arrayed mutually, and laid on a field. Notched flow paths 1d are matched mutually and the insides of the hollow sections 1a are communicated mutually at that time. Consequently, the water of a river is communicated through the notched flow paths 1d. Blocks are communicated simultaneously with the ouside by the flow path holes 2c and the openings 2d, and the flow of water is formed. As a result, spaces formed by the bases 1 and the covers 2 are not closed, and the flowing of water is ensured at all times. Accordingly, the growth environment of algae and microbes can be maintained excellently.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a civil engineering block used for revetment and erosion control such as rivers and coasts, and more particularly to an artificial fish reef block that can be optimally used as a fish reef.

[0002]

2. Description of the Related Art Various types of blocks have been conventionally used as civil engineering blocks installed on rivers and coasts for the purpose of revetment and erosion control. Most of these blocks are arranged in many rivers or coasts to prevent scouring, and there are some blocks that can also be used as artificial fish reefs by utilizing their shapes.

Examples of the artificial fish reef blocks include those disclosed in Japanese Utility Model Publication No. 4-7222 and Japanese Utility Model Publication No. 6-21600. All of these allow a cavity with a circular cross section to be formed by the planar arrangement of each block, and each block has a notch on the bottom surface or a peripheral wall so that these cavities communicate with each other. It has multiple holes for water passage.

In such a block for artificial fish reef, since the block itself has a large surface area, adhesion of algae and its growth can be promoted, and pumice stone is provided in the circular cavity as described in the latter publication. Water can also be purified by packing it, and it can be suitably used for fish reefs.

[0005]

However, various revetment and erosion control blocks, including those described in the above publication, are installed so as to be submerged in the water of a river, for example. The circular cavity has a shape that opens upward. Then, since the array of these blocks is installed so as to be included in the same plane, the upper surface of the block array becomes a substantially uniform plane, and the cavity portion forms a recess.

In such an array of blocks, since the upper surface thereof is a substantially uniform plane, when installed in a river, water tends to flow away as a laminar flow. For this reason,
When the flow of the river is relatively calm, it is difficult to form a flow field that passes through the hollow part, and the supply of oxygen into this hollow part is insufficient, which impedes the growth of algae. Becomes

Further, when the flow velocity of water is large and becomes turbulent during flooding of the river or heavy rain, the flow force of the water into the cavity affects the algae adhering to the block. Or the scour phenomenon of the river bottom located at the bottom of the hollow part may occur, and the arrangement attitude of the blocks themselves may change.

Further, when a debris flow occurs in a river, boulders flow into the cavity and sediment flows in, and algae are buried by these boulders and sediment, which hinders the growth of algae and is used for fish reefs. The function of can be lost.

The problem to be solved in the present invention is to provide an artificial fish reef block which can maintain a stable function for erosion control, revetment and fish reef regardless of the conditions such as the flow of rivers and the wave motion of seawater.

[0010]

DISCLOSURE OF THE INVENTION The present invention is a block for an artificial fish reef that also serves as a revetment for rivers and coasts and erosion control, in which the lower end is open to make the inside hollow and a plurality of peripheral walls are provided. A base that allows water to flow by aligning the flow paths provided in the base, and a cover that covers the hollow portion of the base, and the cover has a planar shape that is smaller than the planar outer shape of the base. It is characterized in that it has an outer shape in which the peripheral surface is tapered upward from the upper end of the hollow portion, and that the cover is provided with a hole communicating with the hollow portion.

[0011]

1 is a front view of a fish reef block according to the present invention, FIG. 2 is a plan view thereof, and FIGS. 3 and 4 are vertical cross sections taken along the lines AA and BB of FIG. 2, respectively. It is a side view.

In the figure, an artificial fish reef block is composed of a base 1 whose outer planar shape is a regular hexagon and a cover 2 which covers the upper surface of the base 1 and is integrally connected thereto. No. 2 is made of concrete as in the case of conventional revetment and erosion control blocks.

The base 1 has a peripheral wall having a substantially uniform thickness, and the inside thereof has a hollow portion 1a having a hexagonal plane cross-sectional shape, and a fixing seat for fixing the cover 2 to the inner edge of the upper end of the hollow portion 1a. The fixed seat 1b is provided with a plurality of engagement holes 1c. Further, on the peripheral wall of the base 1, a cutout channel 1d is cut out from the lower end at approximately the center of each side of the hexagon,
The outside of the base 1 and the hollow portion 1a are communicated with each other by these notch channels 1d. Further, a recess 1e for slinging work is formed at two positions on the peripheral wall of the base 1 in the entire length in the vertical direction, and the lower end of this recess 1e is provided so as to be continuous with the cutout channel 1d on the bottom surface. Therefore, the cutout flow path 1d has a flow path configuration that also communicates with the recess 1e.

The lower end of the cover 2 is the fixed seat 1 of the base 1.
It has a hexagonal shape that can be inserted into b, and has a trapezoidal outer shape that tapers toward the upper end. A protrusion 2a that fits into the engagement hole 1c of the base 1 is provided at the lower end of the cover 1, and a flow path hole 2c is formed in each of the six inclined surfaces 2b toward the upper end. A hexagonal opening 2d is provided at a position coaxial with the hollow portion 1a of the base 1. The cover 2 is formed by fitting the protrusion 2a into the engagement hole 1c.
However, the mortar may be filled in at an appropriate position and joined as necessary.

FIG. 5 is a partial plan view of a fish reef block installed in a river, FIG. 6 is a vertical cross-sectional view of a main portion showing the arrangement of the blocks seen in a direction orthogonal to the flow direction of the river, and FIG. It is a longitudinal cross-sectional view of the main part seen in the flow direction of the river.

As shown in FIG. 5, the fish reef blocks are laid on site so that the hexagonal sides of the bases 1 are aligned with each other. At this time, the respective sides of the bases 1 are in contact with each other, so that the cutout channels 1d formed at the bottom of the base 1 and substantially in the center of the sides are aligned with each other, whereby the hollow portions 1a of the bases 1 are aligned. The inside communicates. Therefore, the water of the river freely flows between the installed bases 1 through the cutout channel 1d,
As shown in FIG. 7, the river water uniformly passes through the hollow portion 1a of each base 1.

In addition to the inflow and outflow of the river water from the cutout flow path 1d, the flow path holes 2c and the openings 2 of the cover 2 are also provided.
Similarly, it comes in and goes out from d, passes through the flow path hole 2c and the opening 2d as it is, or mixes with water on the hollow portion 1a side and flows out from the cutout flow path 1d. That is, the hollow portion 1a includes the cutout channel 1d of the base 1 and the cover 2
Since the flow passage hole 2c and the opening 2d communicate with the outside, a water flow field is formed by the combination of the cutout flow passage 1d, the flow passage hole 2c, and the opening 2d, and the hollow portion 1a and the cover 2 are formed. The space inside is exposed to such a flow field of water, and after being thoroughly mixed and stirred therein, it flows downstream. Therefore, a sufficient flow rate can be secured in the internal space formed by the base 1 and the cover 2 by supplying and stirring water, and oxygen can be sufficiently secured to the algae attached to the surfaces of the base 1 and the cover 2.

Further, as shown in FIGS. 6 and 7, the upper end surface formed by the base 1 laid on the bottom of the river is flat, while the cover 2 covering these bases 1 is a hexagonal truncated pyramid. Since the outer shape is projected upward, the laying surface is formed by the cover 2 with unevenness in a uniform pattern. Therefore, as is apparent from FIG. 7, a flow in a laminar flow state above the upper end of the cover 2 above the water surface is unrelated to the uneven shape due to these covers 2, and the lower side thereof is the upper and lower curves along the cover 2. It becomes a turbulent layer of the combined flow of the uniform flow and the flow detouring around the inclined surface 2b of these covers 2. Then, as described above, the inside of the hollow portion 1a of the base 1 has the cutout channel 1d and the channel hole 2c and the opening 2d of the cover 2.
A flow field is formed by the inflow and outflow of water from.

Due to such water flow distribution, the internal space formed by the base 1 and the cover 2 is not affected by the turbulent layer above the cover 2 even when the river is flooded or heavy rains occur. The place can be maintained, and an environment suitable for growing algae attached to the inner peripheral surface can be maintained.

Further, even if the flow of water in the river is fast, the upper part of the hollow portion of the base 1 is blocked by the cover 2 and the flow of water from the flow passage holes 2c and the openings 2d can be suppressed. For this reason, even if the river bed faces the bottom of the hollow portion 1a of the base 1, the river flow with a vigorous force does not reach the river bed as it is, and scouring of the river bed is prevented. Therefore, the posture of the base 1 is not tilted or displaced, and the functions of erosion control and seawall are not impaired.

Further, by disposing the cover 2 on the hollow portion 1a in the base 1, it is possible to prevent clogging of the hollow portion 1a with earth and sand or boulders even if a debris flow occurs. Therefore, there is no blockage of the space formed by the base 1 and the cover 2, the flow of water between the blocks is always ensured, a sufficient supply of oxygen to the generated algae is maintained, and the function for fish reefs is maintained. Can be continued.

Further, the flow path hole 2c opened in the cover 2
Is upwardly directed from the inclined surface 2b, and the opening 2d is directed upward, so that the flow passage hole 2c and the opening 2d can be used as a window for lighting the hollow portion 1a. Therefore, even if the cover 2 is covered, the space formed by the base 1 and the cover 2 can be exposed to a sufficient amount of sunlight, which is useful for the growth of algae and other microorganisms attached and generated on the surface. be able to.

The hollow portion 1a of the base 1 is filled with pumice or the like as a filter as described in Japanese Utility Model Publication No. 6-21600 mentioned in the section of the prior art, thereby purifying water. You may make it possible.

Further, since each hollow portion 1a of each block portion 1 is communicated with the cutout passage 1d, if compressed air is supplied into any one base 1 from the compressor, it is laid. Air can be sent to the plurality of bases 1, whereby residual water is removed and foreign substances are removed, so that water around the bases 1 can be purified.

The supply of compressed air to the base 1 has the effect of removing foreign matter, etc., and in addition, the pipe of compressed air is connected to the cutout passage 1d of each base 1 to connect the pipe. By constructing an aeration system capable of releasing compressed air into each base 1, the purification efficiency can be further increased, and construction on a large-scale river is also possible.

[0026]

According to the present invention, a cover is provided on the upper surface of the block, and the flow of the upper layer of the block is turbulent by the cover and agitated by the water entering the block, whereby the supply amount of oxygen into the block is increased. Since it is possible to secure the growth environment of algae and other microorganisms, it can be suitably used as a fish reef block.

Further, since the cover is projected upward so that the peaks and valleys are formed between the blocks, not only the flow along the upper surface of the blocks becomes turbulent but also the flow to the base. Prevents boulders and sediment from flowing into each block so that water can always be maintained, and it is possible to protect the algae that have been generated, making it even more suitable for fish reefs.

Further, even when there is no running water on the river bed during a drought period, if the block of the present invention is set lower than the river bed, water permeation, clogging and underflow water between debris and gravel on the river bed can be achieved. The water collection function will also be secured, and it will be possible to store water during the drought period.

[Brief description of drawings]

FIG. 1 is a front view of an artificial fish reef block of the present invention.

FIG. 2 is a plan view of the fish reef block of FIG.

FIG. 3 is a longitudinal sectional view taken along line AA of FIG. 2;

FIG. 4 is a vertical sectional view taken along the line BB of FIG.

FIG. 5 is a partial plan view when a block is laid.

FIG. 6 is a vertical cross-sectional view of a main part of the laid block viewed in a direction orthogonal to the flow direction of the river.

FIG. 7 is a vertical cross-sectional view of the main part of the laid block as seen in the river flow direction.

[Explanation of symbols]

 1: Base 1a: Hollow part 1b: Fixed seat 1c: Engagement hole 1d: Notch flow path 1e: Recessed part 2: Cover 2a: Protrusion 2b: Inclined surface 2c: Flow path hole 2d: Opening

Claims (1)

[Claims] 1. A block for an artificial fish reef, which also serves as a revetment for rivers and coasts and as a erosion control, wherein the lower end is opened to make the inside hollow and the flow paths provided on the respective peripheral walls are aligned by a plurality of arrangements. A base that allows water to flow through and a cover that covers the hollow portion of the base. The cover has a planar shape that is smaller than the planar outer shape of the base, and is above the upper end of the hollow portion. An artificial fish reef block having an outer shape in which a peripheral surface thereof is tapered toward, and a hole communicating with the hollow portion is opened in the cover.