JP2003129442A - Wave attenuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wave attenuator 10 which absorbs and attenuates high waves and swells while maintaining environment and an ecological system in the vicinity of a construction zone. SOLUTION: The wave attenuator 10, which is provided underseas and attenuates the waves, is provided with a plurality of piles 2 erected on the seabed and an inclined plate 1 supported freely movably in the vertical direction to the piles 2. The inclined plate 1 is supported to the piles 2 so as to make the shore side to be higher than the offshore side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wave attenuator for attenuating waves.

[0002]

2. Description of the Related Art The tranquilization of coastal areas is necessary for conservation of eroded coasts, development of marine recreation sites, and fisheries-related developments such as aquaculture and marine farms. Conventionally, a submerged dike is used as one of the wave-dissipating structures used in such a case. The submerged levee is a levee body in which the entire structure is submerged below the sea level, and is installed on the coast of the place where the above-mentioned tranquilization is required.

[0003]

By the way, the submerged dike is constructed by forming a mound on the seabed ground with rubble stones and the like, and installing a concrete structure on it. However, according to such a submerged embankment installation method, the area occupied by the submerged embankment will be large, which will greatly affect the coastal fishery and cause disturbance to the ecosystem of the constructed sea area. In addition, if the seabed is rocky or soft ground, marine civil engineering work such as ground improvement is required, and construction conditions are restricted to prevent environmental damage to the surroundings, making it difficult to install submerged dikes.

Therefore, an object of the present invention is to eliminate high waves and swells while maintaining the environment and ecosystem around the construction area.
An object of the present invention is to provide a wave attenuator that attenuates.

[0005]

In order to solve the above-mentioned problems, the invention according to claim 1 is, for example, as shown in FIG. 1, a wave attenuating device 10 provided below the sea surface for attenuating waves.
In addition, a plurality of stakes 2 erected on the seabed and a sloping plate 1 movably supported in the vertical direction are provided on the stakes, and the sloping plate is higher on the shore side than on the offshore side. It is characterized by being supported by the pile.

According to the first aspect of the present invention, the waves coming from offshore hit the surface of the sloping plate, and the return waves also wrap around the back side of the sloping plate and hit the back surface. This causes the sloping plate to be moved up and down by the waves.
The wave energy can be attenuated because the wave energy is consumed by the vertical movement of the inclined plate. Further, since the wave attenuator is provided below the sea surface, it does not spoil the landscape. In addition, although it has a simple structure in which the pile is provided with an inclined plate that is movable in the vertical direction, it can exhibit the same wave attenuation effect as a conventional submerged dike, and because it is not a bottom structure, Permeability can be secured compared to the bank, and the circulation of seawater in the inland sea and the open sea can be easily performed. Also,
The wave attenuator can be unitized and precast on land, and since the movement of the inclined plate is performed by wave energy as described above, there is no need for external power equipment, and environmental conservation and construction It is possible to reduce the length and the construction cost. In addition, since the sloping plate is supported by the pile so that the shore side is higher than the shore side, the area for receiving the waves is large, and thus the wave damping effect can be further enhanced. Further, the wave attenuator can serve as a fish reef as well as the wave attenuating effect.

According to a second aspect of the present invention, for example, as shown in FIG. 2, in the wave attenuating device according to the first aspect, one end of the sloping plate is rotatably connected to the seabed. Thus, the pile is provided so as to be vertically rotatable around the one end as a fulcrum, and the pile has a substantially arc shape and movably supports the other end of the inclined plate.

According to the second aspect of the present invention, the same effect as that of the first aspect can be obtained, and in addition, since the inclined plate has one end on the offshore side rotatably connected to the seabed, the inclined plate is It does not unnecessarily float and can always exhibit a stable wave attenuation effect.

The invention according to claim 3 is, for example, as shown in FIGS.
As described above, in the wave attenuator according to claim 1 or 2, the inclined plate is configured to be able to float in the sea.

According to the third aspect of the present invention, since the inclined plate is configured to be floatable in the sea, specifically, to have a density close to that of seawater, the inclined plate sinks to the seabed. Since a large amount of wave energy can be constantly attenuated without being lost, the wave attenuation effect can be enhanced.

The invention according to claim 4 is, for example, as shown in FIGS.
As described above, in the wave attenuating device according to any one of claims 1 to 3, a marker 3 protruding above the sea is attached to an upper end portion of the pile.

According to the fourth aspect of the present invention, since the sign protruding to the sea is attached to the upper end portion of the pile, it is possible to inform a ship in the vicinity that the wave attenuator is on the seabed, thereby causing a marine accident. Can be prevented.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a wave attenuator according to an embodiment of the present invention will be described in detail with reference to the drawings. [First Embodiment] First, the configuration of the wave attenuator 10 will be described. The wave attenuator 10 is for attenuating waves rushing from offshore, is arranged at a position relatively close to the coast, and is composed of a sloping plate 1, a pile 2, a light buoy 3, etc., as shown in FIG. ing. The inclined plate 1 is, for example, a plate-shaped structure made of concrete. Inclined plate 1
An insertion hole 11 for inserting the pile 2 is formed in, for example, the four corners of the inclined plate 1.

The insertion hole 11 is formed so as to penetrate obliquely with respect to the thickness direction of the inclined plate 1, and when the inclined plate 1 is inserted into the pile 2, the inclined plate 1 is positioned with respect to the sea surface. It becomes a tilted state. In addition, the insertion hole 11 has a diameter having a sufficient margin for the diameter of the pile 2 so that the inclined plate 1 can be smoothly moved.

The pile 2 supports the inclined plate 1 and guides the movement of the inclined plate 1. The pile 2 is, for example,
Steel pipe piles are used, and they are laid on the seabed corresponding to the intervals of the insertion holes 11.

The light buoy 3 is a sign that prevents a ship from approaching the vicinity of the wave attenuator 10 and is commonly used in offshore construction. The light buoy 3 is connected to the upper end of the pile 2 by a wire or a rope.

To construct the wave attenuator 10, the piles 2 are driven into the construction area on the seabed by a pile driving ship. At that time, pile 2
Are driven along the shoreline at intervals corresponding to the intervals between the insertion holes 11 provided in the inclined plate 1. After placing the piles 2, the slant plate 1 is lifted by a hoist ship, a crane ship, or the like, and the piles 2 are inserted into the insertion holes 11. Insert the pile 2 into the hole 11
After inserting the slant plate 1, the sloping plate 1 is gradually submerged on the seabed. At this time, since the insertion hole 11 is formed obliquely with respect to the thickness direction of the inclined plate 1, the inclined plate 1 is sunk while being inclined with respect to the sea surface. When the offshore one end of the inclined plate 1 reaches the seabed, the installation of the inclined plate 1 is completed. After that, the light buoy 3 is installed on the upper end of the pile 2, and the wave attenuator 10 is constructed.

Since the inclined plate 1 is unitized and precast, there is no need to manufacture it at the construction site, and the construction period at sea can be shortened. Further, the size of the wave attenuator 10 can be appropriately changed according to the environment of the construction sea area, and the applicable sea area can be applied from the vicinity of the coast to a place with a certain water depth. In addition, since the sloping plate 1 is unitized, multiple wave attenuators 10 are arranged side by side according to the length of the coastline and the needs of the orderer to flexibly accommodate all sizes and lengths. can do.

Further, as shown in FIG. 5, one wave attenuating device 10 may be arranged in a plurality along the shoreline, and a row of wave attenuating device groups may be arranged in a plurality of lines. As a result, even if a long-period wave comes in, the wave is attenuated by one of the wave attenuator groups arranged in multiple rows.
It is possible to improve the damping or wave-dissipating effect. At that time, the intervals between the wave attenuating device groups may be equal,
It may be different depending on the topography of the sea area, the wave conditions, and the like. Therefore, the wave attenuator 10 of the present invention can deal with waves of any period by freely changing the arrangement.

Next, the operation of the wave attenuator 10 will be described. Waves rush from the offing, and the inclined plate 1 of the wave attenuator 10
When a wave hits, the kinetic energy of the water particles of the wave acts on the inclined plate 1, and the inclined plate 1 not fixed to the pile 2 moves up and down along the pile 2. As a result, the kinetic energy of the water particles of the wave is lost by moving the inclined plate 1, that is, the wave is attenuated. Further, since the kinetic energy of water particles of waves has a property of becoming larger as it approaches the sea surface and becoming smaller as it approaches the sea floor, it is essential to attenuate the waves near the sea surface. Wave attenuator 1
Since 0 is installed in a state where the inclined plate 1 is inclined with respect to the sea surface, the kinetic energy of large water particles near the sea surface can be attenuated. In addition, since the inclined plate 1 is not fixed, even if a wave having a large kinetic energy rushes in like a high wave, the movement amount of the inclined plate 1 increases, and the kinetic energy is offset. 1 does not need to increase the strength more than necessary.

Therefore, according to the wave attenuator 10 of the present invention, the waves coming from offshore hit the surface of the inclined plate 1, and the return waves also wrap around the back side of the inclined plate 1 and hit the back surface. As a result, the inclined plate 1 is moved up and down by the waves. The wave energy can be attenuated because the wave energy is consumed by the vertical movement of the inclined plate 1. Further, since the wave attenuating device 10 is provided below the sea surface, it does not spoil the landscape. Further, although the pile 2 has a simple structure in which the inclined plate 1 is movable in the vertical direction, the wave damping effect similar to that of the conventional submerged dike can be exhibited and the pile 2 is not a bottom structure. Therefore, permeability can be secured compared to the submerged dike, and the circulation of seawater in the inland sea and the open sea can be easily performed.

Further, the wave attenuator 10 can be unitized and precast on land, and as described above, the movement of the inclined plate 1 is performed by the kinetic energy of the water particles of the wave, so that power from the outside can be used. It does not require any equipment, and it is possible to conserve the environment, shorten the construction period, and reduce construction costs. Further, since the sloping plate 1 is supported by the piles 2 so that the shore side is higher than the shore side, the area for receiving the waves is large, so that the wave damping effect can be further enhanced.

Furthermore, the wave attenuator 10 can diversify the ecosystem by attaching organisms to the inclined plate 1, the pile 2, and the like. In particular, the effect is great on sandy grounds with few species such as beaches. And since the lower side of the inclined plate 1 becomes a shadow, it can play a role as a fish reef. Further, since the light buoy 3 protruding above the sea is attached to the upper end portion of the pile 2, it is possible to inform a nearby ship that the wave attenuating device 10 is present on the seabed and prevent a marine accident.

The inclined plate 1 is not limited to this embodiment. For example, in order to increase the fish collecting effect, it is possible to form a part of the inclined plate 1 into a mesh shape or form the surface into an uneven shape.

[Second Embodiment] First, the configuration of the wave attenuator 20 will be described. The same components as those in the first embodiment described above are designated by the same reference numerals and the description thereof will be omitted. Wave attenuation device 20 according to the present embodiment
In the wave attenuator 10 of the first embodiment, the offshore-side pile 2 is removed and one end on the offshore side is rotatably connected to the seabed. As shown in FIG. 2, the wave attenuator 20 is composed of an inclined plate 6, a pile 7, a connecting fitting 8, a light buoy 3, and the like.

The inclined plate 6 is, like the inclined plate 1, a plate-shaped structure made of concrete, for example. The configuration shown in FIG. 2 may cause the inclined plate 6 to reach the bottom of the sea when the waves are calm. Then, when a wave having a large kinetic energy rushes, the return wave causes the inclined plate 6 to rotate, and the wave can be attenuated. However, since the inclined plate 6 has a higher wave attenuation effect when it is always floating in the sea, the inside of the inclined plate 6 may have a density close to that of seawater, for example, as shown in FIG. Hollow 6
It is supposed to be 2. Further, the inclined plate 6 has insertion holes 61 for inserting the piles 7, for example, in the vicinity of two shore-side corners of the inclined plate 6. Here, since one end of the inclined plate 6 on the offshore side is connected to the seabed, only two insertion holes 61 are required on the shore side. The insertion hole 61 is formed in the thickness direction of the inclined plate 6 with a curvature similar to an arc drawn when the inclined plate 6 is rotated about one end on the offshore side connected to the seabed as a fulcrum.

As the pile 7, a steel pipe pile or the like similar to the pile 2 of the first embodiment is used, but its shape is pivoted about one end on the offshore side where the inclined plate 6 is connected to the seabed as a fulcrum. It is placed on the seabed in a state of being bent to have the same curvature as the arc drawn by the insertion hole 61 at the time. Further, a light buoy 3 is installed at the upper end of the pile 7. The connecting fitting 8 connects one end portion of the inclined plate 6 on the offshore side to the seabed, and is connected to the inclined plate 6 and the seabed so that the inclined plate 6 can be rotated by, for example, a hinge.

When constructing the wave attenuator 20, as in the first embodiment, the insertion hole 61 of the inclined plate 6 is provided after the piles 7 have been driven.
The stake 7 is inserted into the stake and the inclined plate 6 is sunk. When the back surface of the inclined plate 6 reaches the bottom of the sea, the sea bottom and the inclined plate 6 are connected by the connecting metal fitting 8 to construct the wave attenuator 20.

The operation and effect of the wave attenuator 20 are the same as in the first embodiment. However, the inclined plate 6
Since the shape of the pile 7 that guides the movement is different, the pile 7 moves up and down in the first embodiment, whereas in the present embodiment, an arc is drawn with one end on the offshore side of the inclined plate 6 as a fulcrum. Will move.

The inclined plate 6 is not limited to this embodiment. For example, the sloping plate 6 is a hollow concrete structure, but can be freely changed as long as it has a structure capable of floating in the sea. Specifically, as shown in FIG. 4, it is possible to attach a lightweight member 63 to the shore-side end of the inclined plate 6 to increase the buoyancy. Also, the inclined plate 6
You may use the lightweight concrete which mixed the foaming agent etc. in manufacture of. Further, a stopper may be provided at the shore-side end of the inclined plate 6 so that the back surface of the inclined plate 6 does not reach the seabed.

[0031]

According to the first aspect of the present invention, the waves rushing from offshore hit the surface of the inclined plate, and the return waves also wrap around the backside of the inclined plate and hit the backside. This causes the sloping plate to be moved up and down by the waves. The wave energy can be attenuated because the wave energy is consumed by the vertical movement of the inclined plate. Further, since the wave attenuator is provided below the sea surface, it does not spoil the landscape. In addition, it is possible to achieve the same wave attenuation effect as a conventional submerged dike and to ensure the water permeability compared to the submerged dike while it has a simple structure in which the pile is provided with an inclined plate that can move vertically. It is possible to easily circulate seawater in the inland sea and the open sea. In addition, the wave attenuator can be unitized and precast on land, does not require external power equipment, and can achieve environmental protection, shortened construction period, and reduced construction cost. In addition, since the sloping plate is supported by the pile so that the shore side is higher than the shore side, the area for receiving the waves is large, and thus the wave damping effect can be further enhanced. Further, the wave attenuator can serve as a fish reef as well as the wave attenuating effect.

According to the second aspect of the present invention, the same effect as in the first aspect can be obtained, and in addition, the inclined plate does not unnecessarily lift, and a stable wave attenuation effect can be always exhibited.

According to the third aspect of the invention, since the inclined plate does not sink to the sea floor and a large amount of wave energy can be constantly attenuated, the wave attenuation effect can be enhanced. it can.

According to the fourth aspect of the present invention, it is possible to inform nearby ships that there is a wave attenuator on the seabed.
Marine accidents can be prevented.

[Brief description of drawings]

FIG. 1 is a side view and a plan view for explaining a wave attenuator according to a first embodiment of the present invention.

FIG. 2 is a side view for explaining a wave attenuator according to a second embodiment of the present invention.

FIG. 3 is a diagram for explaining an example of an inclined plate in the above embodiment.

FIG. 4 is a diagram for explaining an example of the inclined plate in the above embodiment.

5A and 5B are a side view and a plan view for explaining an example of installation of the wave attenuator according to the above embodiment.

[Explanation of symbols]

1 inclined plate Two piles 3 light buoy 10 wave attenuator

Claims (4)

[Claims] 1. A wave attenuator provided below the sea surface for attenuating waves, comprising: a plurality of piles erected on the sea floor; and an inclined plate movably supported in the piles in the vertical direction. The wave attenuation device, wherein the sloping plate is supported by the pile so that the shore side is higher than the shore side. 2. The wave attenuator according to claim 1, wherein the inclined plate is rotatably connected to the seabed at one end on the offshore side so as to be vertically rotatable about the one end as a fulcrum. The wave damping device, wherein the pile has a substantially arcuate shape and movably supports the other end of the inclined plate. 3. The wave attenuator according to claim 1 or 2, wherein the inclined plate is configured so as to be able to float in the sea. 4. The wave attenuator according to claim 1, wherein a sign protruding to the sea is attached to an upper end portion of the pile.