JPH08109620A - Floating wave dissipation bank - Google Patents

Abstract

PURPOSE: To make a floating wave dissipation bank equipped with buoyancy chambers available for use in long wavelength areas with lesser deterioration in wave dissipation in short wavelength areas while restraining occurrence of reflection waves. CONSTITUTION: A lower buoyancy chamber 5 connecting the lower ends of side buoyancy chambers on both sides of a bank body 2 is provided, and a horizontal porous board 8 connecting the upper ends of the side buoyance chambers on both sides and a front vertical porous board 7 connecting the front ends of the side buoyancy chambers are also provided. Because of the porous boards 7 and 8, occurrence of reflection waves arising from incoming waves 1 is restrained. Energy of the incoming waves 1 is consumed by movement of water along a horizontal passage (a) formed between the horizontal porous board 8 and an inner bottom board 9 and a meandering passage (b) formed between the inner bottom board 9 and the lower buoyancy chamber 5, and thereby the bank can be used in the long wavelength areas.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a floating breakwater having a buoyancy chamber.

[0002]

2. Description of the Related Art As a conventional floating wave breakwater, there is one as shown in FIG. 3, and its breakwater body 02 is arranged in a direction perpendicular to a traveling direction of an incident wave 01. Then, the bank body 02 is moored by a sinker weight (not shown) via the mooring line 03. According to such a floating breakwater, it is possible to provide a calm water area for maintenance of aquaculture fishing grounds, construction of an ocean recreation base, and the like. In addition, such a floating breakwater has the advantage that seawater can be exchanged, and installation and removal work can be realized at low cost in a short period of time.

[0003]

By the way, in the conventional floating wave breakwater as described above, it is used only in the inland sea where the sea condition is mild (the wave period targeted for wave breaking is as short as 5 to 6 seconds or less). It has not been. However, in the coastal areas of Japan, there are many water areas where waves with long wavelengths from the open sea invade, so the available water areas are gradually expanding offshore, and floating waves that can economically respond to longer cycle waves are being developed. A bank is desired.

On the other hand, in the floating breakwater operating in a short period of sea, there is a problem that small vessels such as fishing boats cannot navigate in the vicinity. This is due to the fact that a large disturbed wave is created by mutual interference between the incoming wave and the reflected wave generated from the floating breakwater. The present invention is intended to solve the above-mentioned problems, enables use up to a long wavelength region while suppressing deterioration of the wave-dissipation performance in a short wavelength region, and reduces the generation of a reflected wave. The purpose is to provide a floating breakwater made possible.

[0005]

In order to achieve the above-mentioned object, the floating breakwater of the present invention is provided with side buoyancy chambers provided on both sides of the breakwater body so as to penetrate the water surface, respectively, and these side buoyancy chambers. And a lower buoyancy chamber arranged so as to connect the lower ends of the partial buoyancy chambers, and horizontally provided above the water surface so as to interconnect the upper ends of the side buoyancy chambers on both sides. A perforated plate and a front vertical perforated plate vertically arranged so as to connect the front ends of the side buoyancy chambers on both sides are provided, and a horizontal flow path along the water surface is formed between the perforated plate and the horizontal perforated plate. In order to do so, an inner bottom plate disposed below the water surface below the horizontal perforated plate, a plurality of upper guide plates extending downward from the inner bottom plate in parallel with the front vertical perforated plate, and an upper portion of these Start from the upper surface of the lower tank so that it is inserted with a gap between the guide plates. Provided with a plurality of lower guide plate that has been characterized by serpentine channel is formed between the upper guide plate and a lower guide plate.

Further, the floating breakwater of the present invention is connected to the front end of the horizontal flow path between the front vertical perforated plate and the lower guide plate erected at the front end of the lower buoyancy chamber. A front inner perforated plate for partitioning the front vertical flow path and the meandering front end flow path connected to the front end of the meandering flow path is provided.

Further, the floating breakwater of the present invention comprises a vertical back plate vertically arranged so as to connect the rear ends of the side buoyancy chambers on both sides, and the vertical back plate and the lower buoyancy chamber are connected. Between the lower guide plate erected at the rear end of the rear flow path, a rear vertical flow path connected to the rear end of the horizontal flow path and a meandering rear end flow path connected to the rear end of the meandering flow path are provided. It is characterized in that a rear inner partition plate for partitioning is provided.

[0008]

In the above-mentioned floating breakwater of the present invention, the horizontal perforated plate that connects the upper ends of the side buoyancy chambers on both sides to each other, and the front vertical perforated plate that connects the front ends of the side buoyancy chambers, The incident wave collapses and is converted into a vortex, and the reflected wave from the levee body is greatly reduced accordingly. Further, since the horizontal flow path along the water surface is formed between the horizontal perforated plate and the inner bottom plate arranged below the water surface in parallel with the horizontal perforated plate, when an incident wave arrives, inside the bank body A strong moving flow is generated back and forth along the water surface as a free surface, and the energy of the incident wave is consumed accordingly.

Furthermore, since a meandering flow path is formed between the plurality of upper guide plates vertically extending from the inner bottom plate and the plurality of lower guide plates erected from the upper surface of the lower tank, the bank body is formed. When the incident wave is received, a coupling action of the vibration of the water flow reciprocating in the meandering flow path and the rolling motion of the bank is generated, whereby the energy of the incident wave can be consumed.

The front vertical flow path connected to the front end of the horizontal flow path and the meandering front end flow path connected to the front end of the meandering flow path are partitioned by a front inner porous plate, whereby The movement of the water flow along the horizontal flow path and the meandering flow path is properly performed. Further, the rear vertical flow path connected to the rear end of the horizontal flow path and the meandering rear end flow path connected to the rear end of the meandering flow path are partitioned by a rear inner partition plate, whereby the horizontal flow The movement of the water flow along the channel and the meandering flow path becomes more appropriate.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A floating breakwater as an embodiment of the present invention will be described below with reference to the drawings. FIG.
2 is a sectional view taken along line A-A of FIG. 2 and FIG. 2 is a sectional view taken along line BB of FIG.

As shown in FIGS. 1 and 2, a dam body 2 as a floating body for extinguishing the incident wave 1 is moored via a mooring line 3 with sinkers. Side buoyancy chambers 4 and 4 are provided on both sides so as to penetrate the water surface. The lower buoyancy chamber 5 is provided so as to connect the lower ends of the side buoyancy chambers 4 and 4, and the upper side of the water surface is connected so that the upper ends of the side buoyancy chambers 4 and 4 on both sides are connected to each other. The horizontal perforated plate 8 is arranged horizontally. A front vertical perforated plate 7 is arranged so as to connect the front ends of the side buoyancy chambers 4 and 4 on both sides.

Further, an inner bottom plate 9 is disposed below the water surface below the horizontal porous plate 8 so that a horizontal flow path a can be formed between the horizontal porous plate 8 and the horizontal porous plate 8. Then, a plurality of upper guide plates 9a protruding downward from the inner bottom plate 9 in parallel with the front vertical perforated plate 7 and the lower buoyancy chamber 5 so that the upper guide plates 9a are inserted with a gap therebetween. A plurality of lower guide plates 10 are provided upright from the upper surface of the above, and a meandering flow path b is formed between these upper guide plates 9a and lower guide plates 10.

Further, between the front vertical perforated plate 7 and the lower guide plate 10a standing on the front end of the lower buoyancy chamber 5, a horizontal flow path a is formed.
There is provided a front inner perforated plate 11 for partitioning the front vertical flow channel c connected to the front end of the and the meandering front end flow channel d connected to the front end of the meandering flow channel b.

Further, a vertical back plate 12 is provided vertically to connect the rear ends of the side buoyancy chambers 4 and 4 on both sides, and the vertical back plate 12 and the rear ends of the lower buoyancy chambers 5 are also provided. A rear vertical flow channel e connected to the rear end of the horizontal flow channel a and a meandering rear end flow channel f connected to the rear end of the meandering flow channel b are provided between the lower guide plate 10b standing upright. A rear inner partition plate 13 for partitioning is provided.

Since the floating breakwater of this embodiment is constructed as described above, the horizontal perforated plate 8 for connecting the upper ends of the side buoyancy chambers 4 and 4 on both sides to each other and the buoyancy chamber 4 for the same side. By the front vertical perforated plate 7 connecting the front ends of No. 4 and 4, the incident wave 1 is broken and converted into a vortex, and the reflected wave from the bank 1 is greatly reduced accordingly. FIG. 5 is a graph showing the reflectance of the floating breakwater of the present invention in comparison with that of the conventional one.

Further, since the horizontal flow path a along the water surface is formed between the horizontal porous plate 8 and the inner bottom plate 9 arranged below the water surface in parallel with the horizontal porous plate 8, the incident wave 1 is generated. When it arrives,
A strong moving flow is generated back and forth along the water surface as a free surface inside the bank 2, and the energy of the incident wave 1 is consumed accordingly.

Further, a meandering flow path a is formed between a plurality of upper guide plates 9a vertically extending from the inner bottom plate 9 and a plurality of lower guide plates 10 standing upright from the upper surface of the lower tank 5. Therefore, when the levee body 2 receives the incident wave 1, the vibration of the water flow reciprocating along the meandering flow path a and the rolling motion of the levee body 2 are coupled to each other, whereby the energy of the incident wave 1 is increased. Can be consumed.

Further, the front vertical flow channel c connected to the front end of the horizontal flow channel a and the meandering front end flow channel d connected to the front end of the meandering flow channel b are separated by the front inner porous plate 11. Due to
The movement of the water flow along the horizontal flow path a and the meandering flow path b is appropriately performed. Further, by dividing the rear vertical flow channel e connected to the rear end of the horizontal flow channel a and the meandering rear end flow channel f connected to the rear end of the meandering flow channel b by the rear inner partition plate 13, The movement of the water flow along the horizontal flow path a and the meandering flow path b is performed more appropriately.

As described above, according to the floating breakwater of this embodiment, the incident wave 1 is broken to be converted into a vortex, or the energy of the incident wave 1 is sufficiently consumed so that the incident wave 1 is transmitted. It becomes possible to significantly reduce the height of the wave (transmitted wave height) compared to the incident wave height, and the graph of the transmission coefficient (= transmitted wave height / incident wave height) and wavelength / bank width as shown in FIG. As is clear from the figure, the new type according to the present invention shown by the broken line in comparison with the conventional type shown by the solid line has a significantly improved wave-dissipating performance, and has a practical use range in which the transmission coefficient is 0.5 or less. The design range for can be extended.

That is, as is apparent from FIG. 4, it is possible to use up to the long wavelength region while suppressing the deterioration of the wave canceling performance in the short wavelength region. Further, as described with reference to FIG. 5, the floating wave breakwater of this embodiment can reduce the reflectance of the incident wave. Therefore, due to the significant reduction of the reflected waves, the generation of disturbed waves due to the interference between the reflected waves and the incident waves is reduced, and in this way, it is possible to eliminate the adverse effect on the ship sailing near the floating breakwater.

[0022]

As described above in detail, according to the floating breakwater of the present invention, the following effects can be obtained. (1) A horizontal perforated plate that connects the upper ends of the side buoyancy chambers on both sides to each other and a front vertical perforated plate that connects the front ends of the same side buoyancy chambers make it possible for the incident wave to collapse and be converted into a vortex. And the reflected waves from the levee will be greatly reduced. Therefore, there is no adverse effect on the ships sailing near the floating breakwater. (2) Between the horizontal perforated plate and the inner bottom plate arranged below the water surface in parallel with the horizontal perforated plate, a horizontal flow path is formed along the water surface, so that as a free surface inside the dam body. It causes a violent flow back and forth along the water surface, which causes the energy of the incident wave to be consumed. (3) Since a meandering flow path is formed between the plurality of upper guide plates vertically hung from the inner bottom plate and the plurality of lower guide plates standing up from the upper surface of the lower tank, the bank is incident. When a wave is received, a coupling action of the vibration of the water flow reciprocating along the meandering flow path and the rolling of the bank is generated, whereby the energy of the incident wave can be consumed. (4) The front vertical flow path connected to the front end of the horizontal flow path and the meandering front end flow path connected to the front end of the meandering flow path are partitioned by a front inner porous plate, whereby the horizontal flow The movement of the water flow along the path and the meandering flow path is properly performed. (5) By dividing the rear vertical flow channel connected to the rear end of the horizontal flow channel and the meandering rear end flow channel connected to the rear end of the meandering flow channel by a rear inner partition plate, the above horizontal The movement of the water flow along the flow path and the meandering flow path is more appropriately performed. (6) Due to the above items, the transmittance of the incident wave to the bank can be significantly reduced, and it is possible to use it up to the long wavelength range while suppressing the deterioration of the wave canceling performance in the short wavelength range. Become.

[Brief description of drawings]

FIG. 1 is a transverse sectional view (a sectional view taken along the line AA of FIG. 2) showing a floating breakwater as one embodiment of the present invention.

FIG. 2 is a sectional view taken along line BB of FIG.

FIG. 3 is a cross-sectional view showing a conventional floating breakwater.

FIG. 4 is a graph showing the wave breaking performance of the floating breakwater of the present invention in comparison with the conventional one.

FIG. 5 is a graph showing the reflectance of the floating breakwater of the present invention in comparison with a conventional one.

[Explanation of symbols]

 1 incident wave 2 dam body 3 mooring line 4 side buoyancy chamber 5 lower buoyancy chamber 7 front vertical porous plate 8 horizontal porous plate 9 inner bottom plate 9a upper guide plate 10, 10a, 10b lower guide plate 11 front inner porous plate 12 Vertical back plate 13 Rear inner partition plate a Horizontal flow path b Meandering flow path c Front vertical flow path d Meandering front end flow path e Rear vertical flow path f Meandering rear end flow path

Claims (3)

[Claims] 1. A side buoyancy chamber provided so as to penetrate the water surface on each side of the bank, and a lower buoyancy chamber arranged so as to connect the lower ends of these side buoyancy chambers. Together with the horizontal perforated plate horizontally provided above the water surface so as to connect the upper ends of the side buoyancy chambers on both sides to each other, the front ends of the side buoyancy chambers on both sides are connected vertically. Provided with a front vertical perforated plate disposed, an inner bottom plate disposed below the water surface below the horizontal perforated plate to form a horizontal flow path along the water surface between the horizontal perforated plate, From the upper surface of the lower tank so as to be inserted with a gap between the upper guide plates and a plurality of upper guide plates extending downward from the inner bottom plate in parallel with the front vertical perforated plate. A plurality of upright lower guide plates are provided, and the upper guide plate and the lower plan described above are provided. A floating breakwater, characterized in that a meandering flow path is formed between the inner plate and the inner plate. 2. The floating breakwater according to claim 1, wherein the front vertical perforated plate and the lower guide plate erected at the front end of the lower buoyancy chamber are provided at the front end of the horizontal flow path. A floating breakwater, characterized in that a front inner perforated plate is provided for partitioning a front vertical flow path to be connected and a meandering front end flow path connected to the front end of the meandering flow path. 3. The floating breakwater according to claim 1, further comprising a vertical back plate vertically arranged so as to connect the rear ends of the side buoyancy chambers on both sides thereof. And a lower guide plate erected at the rear end of the lower buoyancy chamber, between a rear vertical flow path connected to the rear end of the horizontal flow path and a meandering path connected to the rear end of the meandering flow path. A floating breakwater, which is provided with a rear inner partition plate for partitioning the end flow path.