JPH08226113A - Low reflective type floating wave dissipation revetment - Google Patents

Abstract

PURPOSE: To reduce a reflected wave by forming a free water space having a slit and an internal float at the impingement wave side of a revetment body rectangular in a plan view, and changing the direction of wave energy on the vertical motion of the float. CONSTITUTION: A free water space with a vertical slit 7 and a float 9d inside is provided at the impingement wave side of a floating wave dissipation revetment using for jointing and mooring a plurality of revetment bodies 5 at constant intervals along a lengthwise direction and at right angles with the progress direction of an impingement wave 2. Also, the impingement wave 2 passes the floating wave dissipation revetment as a transmitted wave in a form damped due to the water breaking effect of the bodies 5. Also, a part of the wave 2 passes the slit 7 and enters a free water space 8. As a result, the wave 2 is broken and causes the float 9d to vertically move. The direction of wave energy is thereby changed and the wave 2 is reduced without impairing a water breaking effect. According to this construction, no turbulent wave due to the interference of incident and reflected waves is not generated, and no adverse effect is given to a ship or the like nearby navigating.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a floating breakwater, and more particularly to a low reflection floating breakwater designed to reduce reflected waves reflected on the front surface of the breakwater.

[0002]

2. Description of the Related Art Conventionally, as a floating body type breakwater, as shown in FIG. 4 (plan view) and FIG. 5 (side view), a plurality of dam bodies 01 are arranged in the longitudinal direction of each dam body 01. The mooring lines 3a and 3b and the sinkers 4a and 4b are moored so as to be at right angles to the traveling direction and to keep a constant distance from each other. It has been proposed to prevent this from penetrating to the rear of the bank. Reference numeral 6 indicates a flat water surface, reference numeral 10 indicates a transmitted wave, and reference numeral 11 indicates a water bottom. Here, the bank 01 is formed of a floating body structure having a rectangular shape in plan view.

[0003]

By the way, in the conventional floating body type breakwater as described above, the wave passing through the breakwater can be reduced, but the front surface of the breakwater reflects the incident wave. It will be reflected in the direction of approach. And this reflected wave interferes with the incident wave to create a greatly disturbed wave, which adversely affects small vessels such as fishing boats sailing in the vicinity, and in extreme cases it becomes impossible to navigate small vessels. There is a problem.

The following facts have been found about the reflected waves in the floating breakwater by experiments.
That is, FIG. 6 shows the experimental results of the relationship between the wave period and the reflectance (= reflected wave height / incident wave height). The solid line in FIG. 6 is the case of the conventional floating body breakwater shown in FIGS. This experimental result shows that the shorter the wave period, the larger the reflected wave in the conventional type.

The present invention is intended to solve the above-mentioned problems in the conventional floating body type breakwater, and is a low reflection type floating type breakwater which suppresses the generation of reflected waves on the front surface of the body. The purpose is to provide a bank.

[0006]

In order to achieve the above object, the low reflection type floating breakwater of the present invention is a floating breakwater having a buoyancy portion and formed in a rectangular shape in plan view. A plurality of groups of the levee body are moored so that the longitudinal direction of each levee body is at right angles to the traveling direction of the incident wave and are kept at a constant interval from each other. A play water space portion is formed on the opposite side, a slit is formed on the front surface of the play water space portion facing the incident wave, and a float is arranged inside the play water space portion. I am trying.

[0007]

In the above-mentioned low reflection type floating wave breakwater of the present invention, the wave entering the water breaks through the slit provided on the incident wave side of the floating breakwater and enters the water retaining space. Furthermore, the direction of the wave energy changes as the float moves up and down due to this wave. Due to these wave breaks and changes in the wave energy direction, the energy of the incident wave is absorbed, and the reflected wave is reduced.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A low reflection type floating breakwater as an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a side view thereof, and FIG. Figure, Figure 3
FIG. 2 is a front view of the B-B arrow in FIG. 1. 1 to
3, the same reference numerals as those in FIGS. 4 and 5 indicate almost the same members.

In the floating body type breakwater of this embodiment, a plurality of ridge bodies 5 each having a hollow portion as a buoyancy portion and formed in a rectangular shape in plan view have incident waves in the longitudinal direction of each ridge body 5. It is moored by using mooring lines 3a, 3b, sinkers 4a, 4b, etc. so as to be perpendicular to 2 and keep a constant distance from each other. A slit (grating) 7 is formed on the front surface (wave incident surface) on the side facing the incident wave 2 of the bank body 5.
Is formed, and four floats 9a to 9d are arranged inside the water retention space 8 such that the floats 9a to 9d can sway vertically due to changes in the wave (water level).

In the above structure, the incident wave 2 passes through the floating breakwater as a transmitted wave 10 in a form attenuated by the wave breaking effect of the bank 5. Further, a part of the incident wave 2 enters the play water space portion 8 through the slit 7 and enters the play water space portion 8 to cause wave waviness. This wave also floats 9
a to 9d move up and down to change the direction of wave energy.

Since the energy of the incident wave 2 is absorbed by the above-described wave collapse and the change in the direction of the wave energy, the reflected wave can be reduced while maintaining the same wave-dissipating effect as the conventional one. it can.

The dotted line in FIG. 6 shows the experimental results of the reflectance of the low reflection type floating breakwater of this embodiment. From the experimental results of FIG. 6, it can be understood that the low-reflection floating-type breakwater of this example is particularly effective for an incident wave having a short wave period.

[0013]

As described above in detail, according to the low reflection type floating breakwater of the present invention, the reflected waves can be reduced without impairing the wave breaking effect of the conventional floating breakwater. it can.
As a result, the incident wave and the reflected wave interfere with each other and a wave that is greatly disturbed is less likely to be generated, and a ship or the like traveling in the vicinity is not adversely affected.

[Brief description of drawings]

FIG. 1 is a plan view of a low reflection type floating breakwater as an embodiment of the present invention.

FIG. 2 is a plan view of the same (viewed along the line AA in FIG. 1).

FIG. 3 is a front view of the same (a view taken along the line BB of FIG. 1).

FIG. 4 is a plan view of a conventional floating breakwater.

FIG. 5 is a side view of the same.

FIG. 6 is a reflection performance chart of the floating breakwater of the present invention.

[Explanation of symbols]

 01 Embankment 2 Incident wave (incoming wave) 3a to 3d Mooring line 4a to 4d Sinker 5 Embankment 6 Level surface 7 Slit 8 Reservoir space 9a to 9d Float 10 Transmission wave 11 Water bottom

Claims (1)

[Claims] 1. A floating body type breakwater having a buoyancy portion and a levee body formed in a rectangular shape in plan view, and a plurality of the levee bodies have a longitudinal direction of each levee body in a traveling direction of an incident wave. They are moored so as to form a right angle and keep a certain distance from each other, and a water retaining space is formed on the side facing the incident wave of the bank, and a front surface of the water retaining space facing the incident wave is formed. A low-reflection type floating breakwater, in which a slit is formed and a float is arranged inside the water storage space.