JPS6172117A - Floating breakwater - Google Patents

Abstract

PURPOSE:To dissipate waves having longer wave length, by a method wherein a vertical wall, extended from the bottom of a boxform structure moored on a water surface, is located in a direction extending at right angles with dashing waves. CONSTITUTION:A vertical wall 3, extended from the bottom of a boxform structure 2 floating on a sea surface, is disposed in a direction extending right angles with incoming waves W. When the incoming waves W acts on the boxform structure 2, an eddy current 7 is produced behind the vertical wall 3, and a wave dissipating effect is produced by an energy loss. Where the vertical wall 3 forms a porous plate or is formed such that it has slits, in addition to an eddy current action, energy is dissipated while waves pass through the pores or slits, a wave dissipating effect is further increased.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a floating breakwater, and more particularly to a floating breakwater that dissipates waves by a box structure moored to the water surface.

[Prior art]

Conventionally, fixed levees made of concrete have been used to eliminate waves that enter ports, etc., but this type of fixed levee has high equipment costs and a long construction period. Furthermore, once constructed, it was difficult to modify, and it obstructed the exchange of seawater.

This means that in relatively deep sea areas such as Hamachi fish farms,
Moreover, this is a big problem when used as a breakwater in cases where a structure that maintains seawater exchange is desired.

For this reason, a floating breakwater structure in which a floating box structure is moored has been considered and proposed. However, this floating breakwater was generally unable to exhibit sufficient effects against long wavelength waves. In other words, the effect of the floating breakwater was sufficient for waves with a small wavelength compared to the size of the box structure, but for waves with large wavelengths, a correspondingly large structure had to be constructed. This resulted in an increase in equipment costs, which was a practical problem.

(Object of the Invention) The present invention has been made in view of the problem of the above-mentioned fixed seawater exchange, and the problem of the floating breakwater's inability to dissipate small-wavelength waves. By taking advantage of these advantages, we aim to provide a floating breakwater with a higher wave-breaking effect, that is, a floating breakwater that can dissipate waves with longer wavelengths.

[Summary of the invention]

In order to achieve the above object, the present invention is characterized in that a vertical wall extending below the bottom surface of a box structure moored on the water surface is provided so as to be perpendicular to the incident wave.
.

〔Example〕

Embodiments of the floating breakwater according to the present invention will be described below based on the drawings.

FIG. 1 is a perspective view of a floating breakwater, and the floating breakwater 1 is composed of a box-shaped structure 2 floating on the water surface and a vertical wall 3 extending below the bottom of the box-shaped structure 2. Ru. This vertical wall 3 is disposed so as to be orthogonal to the incident wave W.

The installation of the vertical wall 3 to the box-shaped structure 2 is shown in Figure 2.
f), the front part where the incident wave W acts as shown in figure +81, the center part as shown in figure tb1, or the rear part as shown in figure C1, or (d) to ( An appropriate number of two vertical walls 3 may be arranged as shown in Fig. f1.

In addition, this vertical wall 3 is formed of a flat plate material (metal plate or prestressed concrete plate, etc.), and in some cases, it is designed to provide a wave-dissipating function while allowing some seawater to pass through. It may be configured as follows. Specifically, it may be formed of a perforated plate having small holes 4 as shown in FIG. ) The slits 6 may be formed in the vertical direction as shown in the figure.

In the above configuration, when the incident wave W acts on the box-shaped structure 2, a vortex 7 is generated behind the vertical wall 3, as shown in FIG. The energy loss of this vortex 7 provides a wave-dissipating effect. Therefore, the same effect can be obtained as if the box-shaped structure 2 had increased water permeability.

In addition, if the vertical wall 3 is formed to have a perforated plate or a slit, energy will be lost while passing through the small holes or slits in addition to the eddy current effect, further increasing the wave-dissipating effect and increasing the exchange rate of seawater. It will help.

FIGS. 5(al to GL) show still another embodiment of the vertical wall 3, and FIG. The figure shows a structure in which rods 10 are supported and a large number of horizontal members 11 are provided in a grid pattern between the support rods 10.

Fig. fb1 shows a horizontal member 11 provided with a spiral body, and the spiral body actively generates a vortex flow.

Figure +81 is a modification of Figure ta+, in which the horizontal member 11 is arranged in a zigzag shape in cross section to facilitate the generation of vortices.

Td) The figure shows the horizontal member 11 having a semicircular cross section with the protruding surface facing toward the waves.

Although Figure +81 shows the cross section of the horizontal member 11 having an X shape, it may also be a Y shape or a combination of an X shape and a Y shape.

(Fig. f1 shows the horizontal members 11 arranged in two stages, front and rear, with a space between them vertically.

The figure (g) shows a horizontal member 11 having a triangular cross section fixed to the support rod 10 with spaces provided vertically and longitudinally.

In this way, the support rod 10 is held on the side of the box-shaped structure 2 by the support member 8.9, and a large number of horizontal members 11 of various shapes are attached to the support rod 10 to form a lattice-like structure. Therefore, it is possible to obtain a seawater exchange effect as well as a wave-dissipating effect.

In addition, a large number of support rods 10 are provided, and the horizontal member 1
The wave-dissipating effect can be further enhanced by using the vertical wall 3 which is divided into multiple stages as in the previous embodiment.

〔Effect of the invention〕

As explained above, by configuring the floating breakwater 1 according to the present invention, the energy of waves with particularly long wavelengths is lost due to the vortex generation effect of the vertical wall 3 provided extending downwardly of the box structure 2. Therefore, even a floating breakwater using a relatively small box structure 2 can obtain the same wave-dissipating effect as a structure with a large volume of water, which is extremely beneficial.

[Brief explanation of drawings]

The figures show an embodiment of a floating breakwater according to the present invention, in which Fig. 1 is a perspective view thereof, Fig. 2 1a) to 1f are explanatory diagrams of an embodiment of a vertical wall, and Fig. (C1 is a diagram showing various structures of vertical walls, Figure 4 is an explanatory diagram of the function of a floating breakwater, and Figures 5(a) to (gl are diagrams explanatory of other embodiments of vertical walls.) - Floating breakwater, 2... Box structure, 3... Vertical wall, 4... Small hole, 5.6... Slit, 7... Eddy flow, 8.9... Support member, 10...Support rod, 11.
...Horizontal member.

Claims (1)

[Claims] A floating breakwater characterized by having a vertical wall extending below the bottom of a box structure moored on the water surface in a direction perpendicular to incident waves.