JP2634660B2 - Erosion prevention block - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a block for preventing erosion or scouring of rivers and coasts (hereinafter simply referred to as “erosion”).

[Related Art] Wave-dissipating blocks for preventing erosion due to waves and currents on the beach are known, and stone blocks, concrete structures, etc. (hereinafter collectively referred to as stone blocks) are provided along the coast slightly away from the coast. There are also known breakwaters, seawalls, jetties, etc., whose tops are constantly exposed on the sea surface, and submerged embankments (hereinafter, these are collectively referred to as embankments).

[Problems to be Solved by the Invention] However, the earth and sand at the base portion of the levee may be eroded by the flow caused by the motion of waves or submarine currents, and the levee may collapse.

On the other hand, in the published patent publication No. 61-501215, in the river construction, by installing on the riverbed a material in which the lower part of a large number of elongated foliates are fixed to a mat, erosion due to water flow is prevented, Techniques have been disclosed to bring sedimentation to a desired state. However, after about one month from the installation, marine organisms such as shellfish adhere to the foliar bodies that have not been subjected to the antifouling treatment, and all the foliar bodies are in a so-called lying state (falling state) due to their weight. . Then, there is a problem that the leaf-shaped body does not exhibit the erosion preventing action when it is in a lying state.

The present invention has been proposed in view of the above-mentioned problems of the prior art, and provides an erosion prevention block that can effectively prevent erosion and maintain the erosion prevention function even when marine organisms or the like are attached. It is an object.

[Means for Solving the Problems] In the erosion prevention block of the present invention, a large number of antifouling elongate leaves are fixed and supported in the internal space of a hollow polyhedron having an opening on each surface.

Here, the polyhedron means all three-dimensional figures having four or more faces. Particularly, a six-plane state is preferable.

In the practice of the present invention, the foliate body is preferably made of a non-toxic, seawater-resistant material having a specific gravity of 0.2 to 0.4 g / cm ³ , for example, polypropylene.

It is preferable that the best block size is appropriately selected in consideration of various conditions of the installation location.

Furthermore, it is preferable that the foliate body is added with an antifouling treatment agent during the manufacturing process or coated on the surface thereof for antifouling treatment so that marine organisms and the like are hardly attached thereto.

In addition to this, it is preferable to combine a plurality of blocks and form the assembly into a shape suitable for the conditions at the site.

In practicing the present invention, a plurality of bars having a circular cross section are installed in parallel on the upper and lower surfaces of the block, or a vertical bar and a horizontal bar having a circular cross section are integrally formed in a lattice shape, and the leaf-like body is formed of each bar. It is preferable that the holding piece is pinched and fixed by a holding piece shorter than the length. It is preferable that the vegetation density of the foliage can be freely set depending on the number of holding pieces.

[Function] Since the leaf is supported in the block, even if a marine substance or the like adheres, the leaf is prevented from lying down due to its weight. The foliar body is supported in the inner space of the block, and maintains a vertical attitude in the water, even in the turbulent zone of the breaking wave where the waves are visible, supplely covers the surface of the sea surface, and the natural sediment forming the sea bottom Blocks flow, promotes sedimentation and suspended matter accumulation, and prevents erosion of sediment at the foundation of the embankment.

Here, since a large opening is formed in each surface of the block, the ocean current or the water current naturally flows into the block and flows out of the block.

Furthermore, since the inside of the block of the present invention provides an environment suitable for the growth of fish and shellfish, it also has a function as a block for cultivation and fishing.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. In the drawings, the same members are denoted by the same reference numerals in principle.

In FIG. 1, an erosion prevention block indicated generally by reference numeral 10 has a hollow rectangular parallelepiped (hexahedron) shape and is made of concrete or steel. In other words, the concrete or steel parts make up the 12 sides of the cuboid.

Each surface of the block 10 has an opening 12 formed therein. On the upper surface U and the lower surface D of the block 10, several rods 14 and 16 having a circular cross section are fixed respectively.
The upper end of many leaf-like bodies 18 located in the internal space 1 of the block 10 is supported by the rod 14 via the holding piece 20, and the lower end thereof is supported by the rod 16 via the holding piece 22. . The holding pieces 20 and 22 are slightly shorter than the rods 14 and 16, respectively, and have "play" to move in the directions of arrows R and L in FIG.

For example, the holding pieces 20 and 22 are approximately 13 cm in length, and are attached to the rods 14 and 16 in an allowable number. If the flow is relatively gentle, it is possible to adjust the play of the holding piece by inserting a spacer between the holding pieces. This spacer is
It is preferable to form a part of the circumference into a notched cylindrical shape.
The spacing between the holding pieces can be adjusted by a spacer or the like to change the vegetation density of the leaf.

The length of the leaves 18 is slightly longer than the vertical distance H between the bars 14,16. As a result, the leaf 18 has a “slack”, and the leaf 18 can withstand the pulling force even if the leaf 18 is pulled by the current or the current due to the “slack”.

In the embodiment of FIG. 1, the leaves 18 are supported in parallel only in the lateral direction (the directions of arrows L and R in FIG. 1), but the holding piece 24 is held between the rods 14 and 14 and between the rods 16 and 16. If installed, the foliate body can be supported in parallel in the vertical direction (the directions of arrows A and B in FIG. 1).

In the embodiment shown in FIG. 2, the upper surface U and the lower surface D are provided with four rods 30 and 34 each having a circular cross section in the longitudinal direction (arrows A and B, directions) in parallel with each other and in the lateral direction. Four (32, 36) arrows are also provided in the directions of the arrows R, L. That is, the bars 30 and 32 are arranged in a grid on the upper surface U,
34, 36 are arranged in a lattice pattern on the lower surface D. The leaf-like body 18 has its upper end and its lower end supported on each side of the lattice via holding pieces 40.

In a mode in which the end of the leaf 18 is supported on each side of the lattice by the holding piece 40, or a mode in which the holding piece 22 of FIG. 1 is supported on the rod 16, the lower end of the leaf 18 is held by the holding pieces 42, 44, 46. The support on the bars 50, 52 via the, 48 is shown in detail in FIGS.

The holding piece 42 shown in FIGS. 3A and 3B is composed of two members 54 and 56 having a cross section in which about 1 / of the circumference is cut out, and the various members 54 and 56 are twisted by 90 ° with respect to each other. The member 54 is provided with a bent portion (lower end) of the folded leaf-shaped body 18 and a fixing rod 58 in its concave portion.
The member 56 is fitted with the round bar 50 in the concave portion. The holding piece 42 is used to support the leaf 18 at a right angle to the rod 50.

4A and 4B, the holding piece 44 is a leaf-shaped body parallel to the rod 50.
The support members 18 and 18 have members 60 and 62 each having a cut-out cross section of about 1/3 of the circumference. The concave portion of the member 60 accommodates the lower end of the leaf 18 and the fixing rod 58, and the member 62 is fitted with the rod 50.

The holding piece 46 shown in FIGS. 5A and 5B is a composite member that connects the plate portion 66 and the bar 50 to the housing portion 64 and the plate portion 66 which are preferably formed integrally when the bar 50 has a small diameter. The ring 68 is made of resin or stainless steel. And stick the foliate 18
It is supported in parallel with 50.

The holding piece 48 in FIGS. 6A and 6B is made of a flexible material such as a synthetic resin, for example, and is formed of a first cylindrical portion 70 in which approximately one-third of the upper part of the circumference is cut out.
And a second cylindrical portion 72 formed integrally below the first cylindrical portion 70 and having approximately one-fourth of the circumference at the upper side. The holding piece 48 is fixed by hooking the second cylindrical portion 72 to the rod 50, and the leaf 18 is held between the first cylindrical portion 70 by a fixing rod 58 fitted to the cylindrical portion 70. Fixed. Each of the holding pieces 40 to 48 has a length of 10 cm to 13 cm.
It is about.

The erosion prevention block of the present invention is more effective when used in combination. For example, as shown in FIG. 7, in order to protect the breakwater T, a plurality of erosion prevention blocks 10 are arranged in the sea (symbol S), and furthermore, a wavebreak block installed on the foundation of the breakwater T (boundary with the seabed G). By using 80 at the same time, the function is more effectively exhibited.

Further, as shown in FIG. 8, if an aggregate 82 is constituted by a plurality of blocks 10 and this aggregate 82 is installed at a predetermined position in water or in the sea, the erosion prevention effect is further improved.

[Effects of the Invention] The effects of the present invention are listed as follows.

(1) The flow of natural earth and sand that forms the sea floor is suppressed, the erosion of earth and sand at the foundation of the embankment is prevented, the shape of the embankment is reduced, and large stone blocks can be used, thereby reducing the construction cost.

(2) Even if a marine substance or the like adheres and becomes dirty, the state in which the foliate body is self-supported in the vertical direction is maintained, and the erosion prevention action does not deteriorate.

(3) The natural seagrass adheres, and the block itself becomes a good fishing reef, so that a good fishing ground can be obtained. In addition, if a foliar agent for growing seaweed is applied or added to the inside of the foliate, it can be used as a natural seaweed cultivation block.

(4) Self-weight is lighter than conventional wave-dissipating blocks.
Since it is hollow, the effect of wave pressure is small. Therefore, the amount of settlement on the seabed or riverbed is small, and the movement of sand is prevented. In addition, sand can be deposited inside the block.

(5) The erosion prevention action is further improved by combining a plurality of blocks.

[Brief description of the drawings]

FIG. 1 is a perspective view showing one embodiment of an erosion prevention block of the present invention, FIG. 2 is a perspective view showing another embodiment of the erosion prevention block, and FIG. 3A is an example of means for supporting a leaf-like body. , FIG. 3B is a perspective view thereof, FIG. 4A is a front view showing another means for supporting the leaf, FIG. 4B is a perspective view thereof, and FIG. FIG. 5B is a perspective view thereof, FIG. 6A is a front view showing other means used for supporting the leaf-like body, FIG. 6B is a perspective view thereof, and FIG. The figure is a sectional side view showing an example of use of the erosion prevention block, and FIG. 8 is a perspective view showing an assembly of the erosion prevention block. 10… erosion prevention block, 12… opening, 14, 16, 30, 3
2, 34, 36, 50, 52: circular bar, 18: leaf, 20, 22, 40, 42, 44, 46, 48: holding piece, I: internal space of block

Claims (1)

(57) [Claims] An erosion prevention block characterized in that a large number of antifouling elongate leaves are fixedly supported in an internal space of a hollow polyhedron having an opening on each side.