JPS61122317A - Long wavelength type floating wave dissipating weir - Google Patents

Abstract

PURPOSE:To effectively dissipate waves of long wavelength, by a method wherein plural columns, having a sloped wall adapted to collect incoming waves, are filled upright in a lower hull having buoyancy. CONSTITUTION:Plural columns 3 are filled upright at proper intervals in a lower hull 2 serving as buoyance for a wave dissipating weir 1, and a side wall 4 of the column 3 is formed so as to collect incoming waves 5 and have a sloped angle theta. A porous panel 6 is located in a position in the vicinity of a portion where a distance between the columns 5 is narrowed to minimum (l), and a platform 8 is installed to the top parts of each column 3 and the porous plate 6. Location of this floating wave dissipating weir causes the incoming waves 5 to be accelerated by means of the slope wall 4 of the column 3 and run to the porous panel 6, and when the waves run through the porous panel, a viscous effect is increased to produce a sufficient wave dissipating effect. This enables effective dissipation of waves of a long wavelength.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a long-wavelength type floating wavebank that floats on the water surface and extinguishes waves having long wavelengths.

[Prior art]

Landing type breakwaters are generally used to extinguish waves entering ports, etc., but if the water depth is deep, such landing type breakwaters not only increase construction costs but also obstruct seawater exchange. Therefore, it is not suitable as a breakwater for fish and shellfish farms. For this reason, floating wave banks have been considered and various structures have been proposed.

One such method involves floating a box-shaped structure (pontoon) on the water surface and mooring it. However, there is a problem with this pontoon-based floating breakwater. In other words, if the floating wavebank is temporarily fixed, from an energy perspective, the incident wave will be ζ! ,
If the transmitted wave is ζ and the reflected wave is ζ1, then ζ1□=♂7+ζ1R−・−−−−−−−−−−(1)
becomes.

However, since the floating wave levee is actually moored, it generates its own waves due to vertical, horizontal, horizontal, rolling, etc. motions.Therefore, in general, equation (1) indicates that the floating wave levee is oscillating. If the transmitted wave is ζ′a9 and the reflected wave is 6, then ζ,′=ζ′? +ζ′♂ −・−・−−
It is expressed as 1-----・(2).

Therefore, there is a problem in that if sufficient wave extinction is achieved, that is, if the transmitted wave j is made small, the reflected wave ζ'♂ becomes large.

By the way, a pontoon type floating breakwater requires a large pontoon to eliminate long waves, which is not only economically disadvantageous, but also causes large oscillations of the pontoon itself, making it difficult to expect much wave-dissipating effect. In addition, in bays and the like, the transmitted waves interfere with the reflected waves of waves generated by sailing ships, impeding the safety of ships.

For this reason, it is desired in this field to develop a long-wavelength floating wave bank that can suppress transmitted waves and reflected waves to a small level.

[Purpose of the invention]

The present invention was devised in view of the above-mentioned problems, and it suppresses the movement of the floating wave bank as much as possible, and by increasing the viscous effect (friction) C,) on the incident waves, the repulsion ζ, 2 = degree? +ζ′♂＋Cv
” −−−−−One song (3) is satisfied, and by using a relatively simple and small structure to dissipate long wavelength waves, construction costs can be reduced and reflected waves can be reduced. The point is that we have also made it smaller.

[Summary of the invention]

In order to achieve the above object, the present invention installs a plurality of columns having slanted walls that collect incident waves on a lower hull that is buoyant and submerged in water, and a platform is provided on the columns. A perforated plate is disposed near the smallest part of the gap between the columns, and a long-wavelength floating wave bank is provided in which the water line is present in the column part and is moored thereto.

〔Example〕

An embodiment of the long wavelength type floating wavebank according to the present invention will be specifically described below with reference to FIGS. 1 and 2.

FIG. 1 is a side view of the wave-dissipating levee 1, and FIG. 2 is a view taken along the line A--A in FIG.

Reference numeral 2 denotes a lower hull which takes care of most of the buoyancy of the breakwater 1, and a plurality of columns 3 are planted on this lower hull 2 at appropriate intervals. The side wall 4 of this column 3 is exposed to the incident wave 5
It is configured to have an inclination angle θ such that it is collected.

A perforated plate 6 is attached in the vicinity where the distance between each column 3 is the minimum l. 7 is a perforated plate provided on the inside of the bay of the breakwater 1, and 8 is a perforated plate provided in each column 3 and the perforated plate 6.
and a platform provided on top of 7.

In this embodiment, the perforated plates 6 and 7 have a double structure, but the perforated plate 6 may have a single structure.

Further, the diameters of the holes provided in the perforated plates 6 and 7 are preferably determined experimentally by taking into consideration the wavelength and wave height of the incident wave.

〔Effect of the invention〕

When the incident wave 5 acts on the wave-dissipating bank 1 having such a structure, it is accelerated by the inclined wall 4 of the column 3 and reaches the perforated plate 6, and when passing through this, the viscous effect is enhanced and a sufficient wave-dissipating effect is obtained.

On the other hand, this wave-dissipating dyke 1 has a small water line area, so there is little oscillation (and even if it moves in the direction of arrow B-B, the action of the perforated plate 6.7 suppresses the waves created by the wave-dissipating dyke 1 itself as much as possible). Furthermore, the perforated plates 6 and 7 can suppress reflected waves inside and outside the bay, which has the effect of increasing the safety of navigating ships.

[Brief explanation of drawings]

Figures 1 and 2 show an embodiment of a long-wavelength floating wavebank according to the present invention. Figure 1 is a side view, and Figure 2 is an A of Figure 1.
-A arrow view. 1-Wave breakwater, 2-Lower hull, 3-Column, 4...-Slanted wall, 5-Incoming wave, 6.7-Perforated plate, 8--Platform, Tag--Floating surface.

Claims (1)

[Claims] A plurality of columns having sloping walls that are buoyant and collect incident waves on the lower hull that is submerged in water are planted, a platform is provided on these columns, and a platform is provided near the smallest part of the gap between the columns. 1. A long-wavelength type floating wave levee, characterized in that a perforated plate is arranged and moored so that a water line is present in the column part.