JP2003158947A - Structure for artificial seaweed - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a structure for artificial seaweed applicable to seabed with a bottom having sharp ruggedness or steep slopes. <P>SOLUTION: The structure has a base member (1) comprising a grillwork by crossing soft ropes in both length and width direction and fixing the ropes at each crossing point with a fixing tool (5) having two adjacent orthogonalizing holes. The base is wrapped with an artificial seaweed member (2) which is a ribbon colored in a seaweed color and having a specific gravity floating in the water, and the wrapped part is covered and fixed with an artificial seaweed fitting member (3), the whole of the structure is then placed on a predetermined place in the seabed by weights (4) or anchors. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of artificial seaweed which serves as a fish reef and also has a function of preventing scouring of a sandy beach on a coast or a river bank.

[0002]

2. Description of the Related Art For the purpose of preventing so-called "scouring", in which sand on a beach or a sandy beach on a riverbank is lost by being washed away by a water stream,
An attempt was made to use artificial seaweed, which was made by growing a plastic ribbon attached to a grid-shaped foundation placed on the bottom of the water like seaweed [Sugawara / Nagai "Port Research Institute Material No. 771, Mar. 199].
4 (Ministry of Transport Port Technology Research Institute)]. As a result of experimentally using this artificial seaweed, it was found that in addition to the effect of scour prevention, the effect as a fish reef is also obtained. The seaweed grows on a plastic ribbon that becomes artificial seaweed, shellfish attach to it, fish lay eggs, and young fish grow. If the sand is not drained by the water current, the sand gradually accumulates, the lattice is buried in the sand, and the artificial seaweed and the real seaweed attached to it are stably grown. In this way, a dense area of seaweed, called what the fishermen call "seaweed beds," is artificially formed.

Recently, as a synthetic resin ribbon, foamed plastic has been used to increase the difference in specific gravity between seawater and river water so that the ribbon can stand up well in water due to buoyancy. If the ribbon is torn into pieces due to a violent ocean current, it loses its effectiveness as an artificial seaweed, and the pieces torn off float on the surface of the water and damage the environment.Therefore, even if you try to reinforce the ribbon by stacking it with a sturdy sheet Has been done.

This artificial seaweed bed needs to have a certain extent of spread in order to exert its effect. Therefore, in practice, several round steel rods or twisted wires are placed in parallel and at right angles, and welded at the intersections to integrate them, for example, a rectangle with a width of 1 m and a length of 2 m. A lattice-shaped body of such a size is created, and a structure with a foamed plastic ribbon attached to it is manufactured, and these are arranged in the required number on the seabed, riverbed, and lakebed (hereinafter referred to as the "seabed"). This forms the seaweed bed.

In the artificial seaweed structure as described above, the inventor uses a steel wire in place of the steel round bar and rationalizes the attachment of the artificial seaweed ribbon to the wire, thereby increasing the man-hours for assembly. Therefore, a structure that can be manufactured at a low cost has been developed and has already been disclosed (Japanese Unexamined Patent Application Publication No.
01-54334).

However, the seabed on which the artificial seaweed structure is arranged is not always flat. Mounds with large stones laid on the seabed are relatively flat, but the natural bottom of the sea varies. Even if a grid is formed with steel wire and a polyethylene coating is applied, it is possible to cope with a gradually changing surface to some extent, but it cannot follow a sudden change. In that case, it was difficult to fix the artificial seaweed, and it was experienced that it might not be useful as a seaweed bed.

[0007]

An object of the present invention is to provide a structure of artificial seaweed for forming a seaweed bed, which is well adapted to severe unevenness of the seabed and steep slopes, and adheres well to the seabed. Another object of the present invention is to provide a flexible one capable of forming such an artificial seaweed bed, which is simple in structure, easy to assemble, and low in cost.

[0008]

The structure of the artificial seaweed of the present invention that achieves these objects is a basic member (1) in which a lattice-like body is formed by ropes, as shown in the structure after assembly as shown in FIG. , An artificial seaweed member (2) to be attached to the base member, an artificial seaweed mounting member (3) that encloses the mounting portion of the artificial seaweed member and is fixed to the base member, and for fixing the combination of each of these members to a predetermined position on the seabed. The fixing member (4) of (1) is an essential component.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The foundation member (1) has a flexible rope that intersects vertically and horizontally to form a lattice, and at each intersection, two closely adjacent holes (51, 5) for passing the rope.
It is fixed by the intersection fixing device (5) having 2) to maintain the lattice. The rope may be made of cotton, hemp or other natural fibers, but from the viewpoint of durability, it is preferable to use synthetic fibers such as nylon, polyethylene, polypropylene and polyester. A diameter of 10 to 12 mm is easy to use, and it has a good balance between durability and cost.

The intersection fixing device (5) can be made of any material, and its manufacturing method is not limited. For example, a cast product made of steel may be used, a short steel pipe may be crossed and welded, or a product made by brazing a pipe such as brass may be used. As a preferred embodiment, a block molded by means such as plastic injection molding as shown in FIG. 3 is recommended. This block may be rounded if it is desired to reduce the catch during handling and installation.

If the size of the holes (51, 52) is selected so that the rope can easily pass therethrough, the formation of the lattice is facilitated. It is expected that the grid will be stable if there is enough friction to allow the rope to barely pass, but in reality, once the rope is assembled, the grid shape will not collapse as expected and the artificial seaweed mounting member will be used. The attachment maintains the grid. However, it is not appropriate to attach the artificial seaweed member between all the lattices, and there are places where it is not attached, so if necessary to maintain the lattice spacing,
Only the artificial seaweed mounting member may be attached to the portion where the artificial seaweed member is not attached.

The artificial seaweed member (2) has a large number of parallel slits (22) in the longitudinal direction with respect to a rectangular sheet having a specific gravity that floats on water and colored in the color of seaweed, leaving a central portion (21). ), And a ribbon (23) is formed. Materials should be selected that have the ability to withstand the conditions under which the artificial seaweed structure is installed, such as changes in water temperature, the strength of sunlight and wind waves, or the attack of marine life.

Specifically, a sheet of foamed plastic, particularly foamed polyolefin, is suitable. The expansion ratio is
It is 2 to 10 times, preferably 6 to 8 times. The higher the expansion ratio, the higher the buoyancy in water, but it should not be so high to ensure the durability of the ribbon. Sheet thickness is 1
-5 mm, preferably 1-3 mm. The coloring is
In addition to black, green, red, it will be suitable for artificial seaweed beds to be realized. As mentioned above, in foamed plastic,
It is more preferable that a woven fabric, a non-woven fabric or a plastic sheet is laminated to improve durability.

The artificial seaweed mounting member (3) has a tubular body (31) having an inner diameter corresponding to the size of the rope thickness plus the thickness of the sheet constituting the artificial seaweed member It has a shape having two flat plate portions (32, 32 ') that open in a line and extend from there in parallel to the radial direction.
This member is made of a material that has some elasticity as well as rigidity. Usually, low to high density polyethylene or polypropylene is preferred. Although a method of manufacturing the member is arbitrary, this method is recommended because it can be easily manufactured by a combination of extrusion molding and cutting.

The fixing member (4) is a weight having a weight sufficient to sink the combination of the respective members to the bottom of the water, or an anchor for fixing the combination to the bottom of the water. Which to use may be determined depending on the strength of the water flow acting on the artificial seaweed, the difficulty of construction, and the like. The example shown in FIG. 5 is a concrete weight having a substantially cubic shape.

In assembling the artificial seaweed structure of the present invention, first, a required length (for example, 2 m in length and 1 in width) is set.
m), the prepared rope is crossed, and the intersection is fixed by the intersection fixing device (5) to form a lattice to form the lattice-shaped base member (1), and the rope is formed in the central portion of the artificial seaweed member. According to the process of winding (21) and fitting the artificial seaweed mounting member (3) on it.

When attaching the artificial seaweed member, if the tubular portion of the artificial seaweed attaching member relies solely on the force for tightening the artificial seaweed member toward the rope, the end of the flat plate portion may open and the tightening may become insufficient. In order to secure the tightening force, it is preferable to add a tightening means to the flat plate portions (32, 32 '). This enhances the force with which the artificial seaweed attachment member fixes the artificial seaweed member. Although the structure of the tightening means is arbitrary, it is needless to say that the tightening means can be easily used and is inexpensive. As shown in FIG. 4, use a plastic molded product with a pin (6
There is a fastener (6) which is composed of a combination of 1) and a fixer (62) and cannot be returned by the fixer when a pin is passed through, and is used in various fields. This is also conveniently available here.

[0018]

[Example 1] [Example 1] Two ropes made of polyethylene fiber having a diameter of 10 mm cut into a length of 3 m and having a length of 2.
Four pieces cut into 1 m pieces were prepared, 3 m pieces were arranged on both outer sides, and 2.1 m pieces were arranged on the inside at 20 cm intervals. Separately, 11 short ropes cut to a length of 1.1 m were prepared, and were made to intersect at 20 cm intervals. At their intersection,
Place the cross-point fixture made by injection molding of polyethylene in the shape shown in Fig. 1, 1m x 2m, and the grid pitch is about 20.
A rectangular grid of cm was prepared. The T-shaped portion of the edge was fixed by folding back the end protruding from the intersection fixing tool and binding it with nylon tape. The long ropes on both sides were folded back and tied at their ends to form a loop for anchoring to the bottom of the water.

A sheet of about 1 mm thick made of expanded polyethylene colored with green color (foaming ratio of about 4) has a width of 15 cm and a length of 20.
As shown in FIG. 2, a 0 cm piece was cut with parallel slits outwardly leaving a central width of 16 cm to prepare an artificial seaweed member. Separately, the artificial seaweed attachment member having the shape shown in FIG. 1 was formed by extrusion-cutting of polyethylene.

The loops at the four corners of the base member are supported by pillars, and the artificial seaweed member is folded in half from the center line, but the folded portion is placed on the vertical and horizontal ropes, and the artificial seaweed mounting member is fitted. , Both ends were fixed with the above fasteners. The part to which the artificial seaweed member is attached is shown in FIG.
The part indicated by the thick line and the part indicated by the thin line are only the rope. The artificial seaweed members are attached to every other horizontal rope in a zigzag arrangement, so that there are a total of 25 sets.

Two sheets of these artificial seaweed structures each having a length of 7
They were arranged in a circulating test water tank of m × 3 m in width, and one concrete block having a weight of about 10 kg was used as a weight, and they were fixed by being connected to loops at four corners. Water flow speed 1
When the seawater was circulated at 3 knots, the artificial seaweed fluctuated in the flowing seawater, and it looked like a real seaweed bed. After continuing this test for several hours to half a day, the circulation was stopped and the structure of the artificial seaweed was pulled up and observed, but no particular change was observed.

[0022]

The structure of the artificial seaweed of the present invention is
The effect of the artificial seaweed structure proposed earlier, that is, the ribbon that becomes the artificial seaweed is formed in a shape in which one sheet is connected at the root part, it is wound around the base member, and it is cylindrical plus parallel from above. It is possible to directly enjoy the advantage of fitting a fixing member having a flat plate shape and adding a tightening member as needed, which is realized with a simple configuration. Therefore, the labor required for manufacturing is remarkably less than that of the artificial seaweed structure before that. Each component can be easily manufactured by extrusion molding or injection molding of plastic with some post-processing depending on the case, so that the cost can be kept low.

In addition to these advantages, the manufactured artificial seaweed structure can be flexibly deformed in response to unevenness and inclination of the water bottom. Therefore, the artificial seaweed structure having a steel wire foundation is applicable. It can be used without problems even in places where it is not possible. It is unique in the structure of this artificial seaweed that it is not bulky for transportation and storage, and is lightweight and easy to handle.

[Brief description of drawings]

FIG. 1 is a partial perspective view showing the structure of a representative example of a structure of an artificial seaweed according to the present invention.

FIG. 2 is a development view of an artificial seaweed member used in the present invention.

FIG. 3 is a perspective view showing an example of an intersection fixing tool used in the present invention.

FIG. 4 is a sectional view showing an example of a fastening member used in the present invention.

FIG. 5 is a plan view showing the attachment position of the artificial seaweed member to the base member in the embodiment of the present invention.

[Explanation of symbols]

1 Foundation member (rope) 2 Artificial seaweed components 21 Central part 22 Slit 23 Ribbon 3 Artificial seaweed mounting member 31 tubular body 32, 32 'flat plate portion 4 Fixing member (weight) 5 intersection fixture 51,52 Holes for passing ropes 6 fasteners 61 pin 62 fixer

Claims (4)

[Claims] 1. A base member (1) in which a lattice is formed with a rope, an artificial seaweed member (2) attached to the base member, and an artificial seaweed attachment member (3) for wrapping the attachment portion of the artificial seaweed member and fixing it to the base member. ) And a fixing member (4) for fixing the combination of these members at a predetermined position in water, which is an essential component of the artificial seaweed structure, wherein the base member (1) is flexible. The ropes are crossed vertically and horizontally to form a lattice, and at each intersection, the lattices are fixed by an intersection fixing device (5) having two holes (51, 52) that are close and orthogonal to each other for passing the rope. The artificial seaweed member (2) is a rectangular sheet colored with seaweed and having a specific gravity that floats on the water, and the artificial seaweed member (2) has a large number of parallels in the longitudinal direction except the central portion (21). Ribbon (23 ) Is formed, the artificial seaweed attachment member (3) is made of a material that has rigidity and some elasticity, and the dimension of the rope thickness plus the thickness of the sheet that constitutes the artificial seaweed member. A cylindrical body (31) having an inner diameter corresponding to that has two flat plate portions (32, 32 ') that open in a single line along the axis and extend in parallel to the radial direction from the tubular body (31) The fixing member (4) is a structure of artificial seaweed characterized in that the fixing member (4) is a weight of a weight sufficient to sink the combination of the respective members or an anchor for fixing the combination to the water bottom. 2. The artificial seaweed structure according to claim 1, wherein the intersection fixing device (5) is a block of a plastic molded product. 3. The artificial seaweed structure according to claim 1, wherein the artificial seaweed member (2) is formed of a foamed plastic sheet or a laminated material of the foamed plastic sheet and a woven fabric, a nonwoven fabric or a plastic sheet. 4. The artificial seaweed structure according to claim 1, wherein a fastener (6) is added to the flat plate portion of the artificial seaweed mounting member (3) to enhance the force with which the artificial seaweed mounting member fixes the artificial seaweed member. .