JPH0321134B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a method for constructing a fish reef suitable for spawning squid, and more specifically, a method for constructing a fish reef suitable for spawning squid, and more specifically, a concrete wall aggregate with a radial horizontal cross section is poured into one piece, and then a gap between the walls is formed. In addition, it is easy to manufacture by inserting mortar or impregnated shelf into FRP, corrosion-resistant fiber structure or corrosion-resistant fiber structure and then installing it in the sea. This article relates to construction methods for spawning reefs suitable for spawning.

Squids are a desirable marine resource because they grow quickly and can be spawned and caught in nearby waters. In particular, spear squid are expensive because they are large and delicious, and it is desired to actively raise eggs. Squid prefers to spawn in the dark ceilings of caves near the ocean floor from January to March. For this reason, attempts have been made to manufacture artificial spawning reefs out of concrete and place them on the ocean floor, which have a multi-area rock ceiling and are dimly lit, allowing squid to enter and exit from any direction at will, and have had considerable success.

The present invention further advances the invention by effectively using a smaller amount of concrete, making the work easier, and using materials that create an environment where squid are more likely to spawn, thereby achieving high spawning efficiency and spawning reefs suitable for the growth of young fish. The purpose is to provide

That is, unlike the conventional method of stacking rock ledges in multiple stages using concrete, the present invention manufactures a support body in which concrete walls extending radially from a central axis are integrally cast, and then This is a construction method in which shelves made of plastic or fiber material, which correspond to rock ceilings, are fixed in multiple stages between adjacent walls.

According to this method, the shelves are lightweight and the structure of the support is simple, making it extremely easy to place.The structure itself is stable, and the shelves can be optimally tailored to the ocean current, water depth, and type of squid. You can use the material and set the optimal shelf spacing.

The present invention will be explained in detail below.

The support according to the invention is manufactured using concrete, preferably reinforced concrete. That is, at least three concrete wings extend vertically from the upright central axis. Although the angle between the wings can be set freely, as the number of wings increases, the depth of the shelf relative to the entrance width will inevitably increase, and the proportion of the dimly lit area in the fish reef installation area will increase.

The wing may be a simple plate shape, but it may also have a wide tip, that is, an outer edge, as shown in FIG. 2, or a narrow base. Further, a through hole for drainage may be formed in the wing surface. The vertical plane of the wing requires some kind of attachment means to provide a shelf. For example, by pushing a corrosion-resistant hook made of metal or high-strength plastic into the concrete, or by drilling screw holes in the concrete itself, or in some cases by drilling through holes in the wing surface, A groove may also be provided.

The shelf material according to the present invention is generally a fiber-reinforced plastic called FRP, a corrosion-resistant fiber structure, or in the case of a fiber structure, it can be coated with or impregnated with mortar to give it a rock-like feel. Materials with added rigidity can also be used.

The fiber structure is polyester, nylon,
A thick material made of synthetic fibers such as polyethylene or polypropylene, so-called non-woven fabric, is preferable; it is fundamentally different from a so-called net, and requires sufficient resistance to the flow of water.
In addition, dark-colored materials are preferred in order to achieve the dimness that cats like.

Further, it is preferable that the shelves are not provided closely between the wings, but that a space is provided near the center or near the wings. In this way, this space allows the force of the tidal current to escape and alleviates the buoyancy force exerted on the spawning reef itself.

The present invention will be specifically described below with reference to Examples and drawings.

FIG. 1 is a perspective view. 1 is a central shaft made of concrete, and four wings 2 are integrally cast from the central shaft 1 at right angles. 3 is a shelf, and 4 is a hook for fixing the shelf 3 between adjacent wings, the legs of which are embedded in the concrete wing 2.

In this embodiment, the shelves 3 are arranged in six stages, and the interval between the shelves is about 30 cm, but the number of stages may be two or more, and the interval can be set freely. Approx. thickness for shelf material
A polyethylene nonwoven fabric of 1.2 mm and a water permeability coefficient of 1.1×10 ^-1 was impregnated with mortar and hardened. That is, as shown in FIG. 4, there are mortar layers 6 on both sides of the fiber structure 5, and the mortar material has penetrated into the inside of the fiber structure 5 to some extent. Furthermore, when a plastic-containing cement is used as the cement for mortar, the bending strength increases and cracks are less likely to occur.

Figure 2 shows an example in which the blade 2 has six pieces, the thickness of the blade is larger at the tip than near the center axis, and a fiber structure is used as the shelf material, and Figure 3 is a part of Figure 2. It is an enlarged view. In this case, the area between the shelves was darker and quieter than in the case of Figure 1, and a better spawning effect was obtained. The fiber structure is a brown polyester nonwoven fabric with a thickness of 2 mm, and a water permeability coefficient of 2.0 × 10 ^-2 as measured according to JIS A 1281.
If it is less than cm/sec, it can withstand use.

In this example, the tip of the triangular nonwoven fabric is not fixed to the wing 2, but is allowed to swing around the central axis 1, allowing the buoyant force caused by the current to escape from around the central axis, thereby reducing the risk of the spawning reef tipping over. do not have.

FIG. 5 shows another shelf fixing method, in which reference numeral 7 indicates a through hole drilled in the wing 2, into which a stopper 10 having a hook 4 at one end is inserted. The other end of the stopper 10 is threaded so that this portion protrudes from the opposite side of the wing 2, and this protrusion is tightened with a nut. Reference numeral 3 denotes a shelf made of a glass fiber-reinforced polyester plate, and a hole 11 for engaging with the hook 4 is provided at the edge. In this case, a gap is left between the shelf 3 and the wing 2 due to the stopper 10, which forms an escape route for the tidal current and prevents it from falling over. Another fixing method is to provide a groove 12 in the blade 2, as shown in the lower part of FIG. 6, and insert the shelf 3 into the groove 12 via a water-resistant adhesive. When using a fixing means as shown in the lower part of FIG. 5, no gap is left between the blade 2 and the shelf 3, so it is possible to leave a drainage gap 13 near the central axis 1 as shown in FIG. desirable.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a perspective view, FIG. 2 is a plan view, FIG. 3 is a partially enlarged sectional view of FIG. 2, FIG. 4 is a sectional view of a shelf material, and FIG. 6 through 6 are explanatory views showing how to attach the shelves. In the drawings, 1 is a central axis, 2 is a wing, 3 is a shelf, 4 is a hook, 5 is a fiber structure, 6 is a mortar layer, 7 is a through hole, 8 is a male screw, 10 is a stopper, 11 is a hole, 12
is a groove, and 13 is a void.

Claims (1)

[Claims] 1. After concrete wings with at least three shelf fixing means are cast vertically and integrally from the upright central axis, FRP, corrosion-resistant material is installed between adjacent wings via the above shelf fixing means. 1. A method for constructing a squid spawning reef, which comprises inserting and fixing two or more shelves coated with or impregnated with mortar into a corrosion-resistant fiber structure or a corrosion-resistant fiber structure.