JPH0730734Y2 - Floating body of a breakwater - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a floating body of a floating breakwater used for maintenance of fishing grounds for the purpose of breaking waves in aquaculture facilities, and maintenance of fishing ports for the protection of fishing boats. It is a thing.

[Prior Art] An example of a conventional floating breakwater intended for short-period waves (short-wavelength waves) will be described with reference to FIG. 5. A wall surface d on the upstream side in the approach direction of the wave b and a downstream side wall surface e in the approach direction of the wave b. Similarly, the wall surfaces (not shown) on both left and right sides orthogonal to the wave intrusion direction are made perpendicular to the water surface c, and the horizontal top surface f and bottom surface g are fixed to the upper and lower parts of each wall surface d, e. , The cross-sectional shape of the floating body a forming the floating breakwater in the direction of entry of the wave b is formed into a hollow rectangular shape, so that the floating body a can be held near the water surface. The area near e is moored to an anchor fixed to the seabed via a mooring line i.

When the wave b enters the floating body a, the wave b becomes the wave b of the wave body a.
The transmitted wave passing through the floating body a on the wall surface d on the upstream side in the entry direction is reduced so that the water surface on the downstream side in the entry direction of the wave b is extinguished.

[Problems to be solved by the invention] However, in recent years, improvement of the wave breaking performance of a floating breakwater has been demanded. Due to the improvement of the wave breaking performance, the floating body is made smaller for the same required wave breaking performance, which is economical. It is necessary to enhance the mechanical effect, but the floating body having a rectangular cross section as in the above-mentioned conventional example cannot obtain a sufficient effect.

Further, in the floating body having a rectangular cross section, since the wall surface d is orthogonal to the water surface with respect to the wave entering direction, the reflected wave becomes large, and the wave drift force acting on the floating body also becomes large accordingly. Therefore, the floating body a and the anchor h There is a problem that the tension is increased in the mooring line i between and.

The present invention has been made in view of the above circumstances and has an object to reduce the floating body and the mooring line by improving the wave-dissipating performance and reducing the wave drift force that the floating body receives.

[Means for Solving the Problems] According to the present invention, the cross-sectional shape of the wave intrusion direction is such that the wall surface on the upstream side of the wave intrusion direction and the wall surface on the downstream side of the wave intrusion direction are in the wave intrusion direction and downstream side. It is characterized in that it has a parallelogram shape inclined in an upward slope and has a hollow inside.

[Operation] When a wave enters the floating body, the upstream side wall surface in the wave entry direction and the downstream side wall surface in the wave entry direction are formed in a parallelogram shape that inclines in an upward slope toward the downstream side in the wave entry direction. Therefore, the transmitted wave is smaller than that of the conventional floating body having a rectangular cross section with respect to the short-period wave, and thus the wave-dissipating performance can be improved and the wave drift force received by the floating body can be reduced. Since the inside of the floating body is hollow, the structure is simple, the floating body can be formed in a short period of time, the manufacturing cost can be reduced, and the floating body itself has a completely closed shape. Therefore, the strength of the floating body against external force such as wave force can be improved.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

1 and 2 show an embodiment of the present invention.
The floating breakwater floating body 1 has a width B more than the width B of the wave 2 in the entering direction.
The length L in the longitudinal direction orthogonal to is increased, and the cross-sectional shape of the floating body 1 in the approach direction of the wave 2 has a top surface 3 and a bottom surface 4 which are arranged at a height H and are parallel to each other. And a wave which is fixed to the bottom surface 4 and the top surface 3 at the upper and lower ends thereof, and which slopes in an upward slope toward the downstream side in the approach direction of the wave 2, and in which the upstream side wall surface 5 in the approach direction of the wave 2 and the wall surface 5 slopes in parallel. A parallelogram with a hollow inside is formed by the wall surface 6 on the downstream side of the entry direction of 2 and the vertical wall surfaces on both left and right sides orthogonal to the entry direction of the waves.

The floating body 1 and the anchor 7 fixed to the seabed are connected by mooring lines 8 so that the upper portion of the floating body 1 floats above the water surface and the lower portion sinks below the water surface.

In addition, 9 is the water surface, 10 is the water line, D is the water line, and α is the wall surface.
The inclination angles of 5 and 6 with respect to the perpendicular.

The wave-dissipation performance is improved by reducing the transmitted wave that passes through the floating body 1 with respect to the entry of the wave 2, but the component of this transmitted wave is due to the transmitted wave when the floating body is fixed and the vertical oscillation (vertical movement in the vertical direction). It is broadly divided into four types: divergent waves, lateral waves (horizontal motion in the width B direction), and lateral waves (rotational motion orthogonal to the width B direction).

In the region where the wave period is short, the sway of the floating body is small, and the transmitted wave when the floating body is fixed is dominant among the above components, but like the embodiment shown in FIGS. 1 and 2, the wall surface 5, When 6 is inclined upward with respect to the incoming direction of the wave 2, the transmitted wave when the floating body is fixed becomes smaller than in the case of the conventional rectangular cross section,
Therefore, the overall transmitted wave also becomes small.

Figures 3 and 4 show the regular and irregular waves (Bret, respectively).
Fig. 3 shows experimental results of comparison of wave-dissipating performance between a floating body 1 having a parallelogram cross section and a conventional floating body a having a rectangular cross section with respect to a schneider (light spectrum). The horizontal axis is the wavelength-width ratio λ / B, and the vertical axis is the wave transmittance C _T (transmitted wave height / incident wave height)
The case of the conventional floating body a is shown by a broken line, and the case of the floating body 1 of the above-mentioned embodiment is shown by a solid line. In both cases, the ratio of height H to width B and the ratio of draft D to width B are made equal.

3 and 4 show that the floating body 1 of the above-mentioned embodiment has a smaller wave transmittance C _{T in} the short period region than that of the conventional floating body a, and therefore has excellent wave-dissipation performance. It indicates that

[Effects of the Invention] According to the present invention, since the wave-dissipating performance is improved in the short-period region compared to the conventional floating body, the same required wave-dissipation is required in the case of the floating-wave breakwater whose short-waves are to be extinguished. As for the performance, the floating body [width B x height H] can be made smaller than the conventional floating body, so it can be made economically, and therefore the wave drifting force becomes small and the mooring line can be made small. In addition, wave collapse tends to occur on the inclined wall surface, and this wave collapse reduces the reflected wave from the floating body. Therefore, the stationary force in the horizontal direction acting on the floating body, that is, the wave drift force is reduced, so that the mooring line is small. In addition, since the inside of the floating body is hollow, the structure is simple, the floating body can be formed in a short period of time, and the manufacturing cost can be reduced. Completely blocked Since that is the Jo, it can achieve various excellent effects such can improve the strength of the floating body with respect to an external force of wave power and the like.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of a floating breakwater of the present invention,
2 is a perspective view of a floating breakwater using the floating body of FIG. 1, 3
FIG. 4 is a graph showing the comparison of the wave-dissipation performance of a floating body having a parallelogram cross section according to one embodiment of the present invention with respect to a regular wave and a conventional floating body having a rectangular cross section according to experimental results. FIG. A graph showing the comparison of the wave-dissipating performance of a floating body having a parallelogram cross section of the example and a conventional floating body having a rectangular cross section by experimental results,
FIG. 5 is a sectional view of a floating body of a conventional floating breakwater. In the figure, 1 is a floating body, 2 is a wave, 3 is a top surface, 4 is a bottom surface, and 5 and 6 are wall surfaces.

Claims (1)

[Scope of utility model registration request] 1. A parallel four-sided cross-sectional shape in which the wall surface on the upstream side with respect to the wave entering direction and the wall surface on the downstream side with respect to the wave entering direction are inclined in an upward slope toward the wave entering direction and the downstream side. A floating body of a breakwater, which has a shape and a hollow inside.