JPH04254607A - Wave breaking facility - Google Patents

Abstract

PURPOSE:To obtain a wave crushing facility to be utilized for leisure sports such as surfing by concentrating waves, increasing a wave height, and breaking them at a constant position. CONSTITUTION:Using a refraction phenomenon of waves by means of a lens of a submerged structural body 10, the waves are concentrated toward a focul point 13 of the lens. The waves concentrated to increase their height further increase their height by action of a mount-like structural body 20 provided in a sea range around the focul point 13 to exceed a breaking limit wave height to be broken.

Description

[Detailed description of the invention]

0001

[Industrial Field of Application] The present invention relates to wave breaking facilities, in particular:
This invention relates to a wave breaking facility that uses the deformation of waves due to changes in water depth to break waves at a predetermined position.

0002

[Prior Art] Conventionally, wave refraction, a phenomenon in which the wave speed decreases at shallow water depths, a wave phase lag occurs, and the wave direction changes, has been utilized to concentrate waves and release wave energy. Wave control structures that aim at effective utilization are known. Examples of such wave control structures include a submerged horizontal plate in which a flat plate with a convex lens shape is installed in the sea, and Japanese Patent Application No. 2-208 filed by the applicant of the present application.
Examples include the wave control structure described in No. 137, in which substantially cylindrical members or substantially cylindrical members are arranged in a lens-like shape as a whole. In addition, by installing wave power utilization facilities, such as wave power generation devices, in sea areas where waves are concentrated using these wave control structures, wave energy can be absorbed and used, and waves can be dissipated to create calm sea areas. something is known.

0003

[Problems to be Solved by the Invention] However, such conventional wave control structures are not equipped with any equipment for breaking waves, and the only way to expect waves to break is due to natural wave breaking due to shallow sea deformation. Therefore, the area where the waves break is not constant, and even if the waves concentrate near the focal point and the wave height increases, no measures have been taken to actively break the waves at that location. There is a problem in that it is not possible to obtain high breaking waves.

[0004]The present invention has been made to solve the above problems, and its purpose is to create breaking waves with high ridges suitable for leisure activities such as surfing in a certain sea area near the focal point of a lens-type wave control structure. The aim is to provide wave breaking facilities that can be easily obtained.

[0005]

[Means for Solving the Problems] The present invention has been made in view of the above object, and its gist is to provide a lens-shaped submerged structure installed at a predetermined water depth based on the correlation with the wavelength of waves; It is located in a wave breaking facility consisting of underwater protrusions installed in the sea area near the focal point of the lens.

[0006] Here, the predetermined water depth based on the correlation with the wave wavelength is the water depth at which waves are affected by the seabed, calculated from the wave wavelength, and specifically, the water depth that is shallower than 1/2 of the wave wavelength. Tell the depth of the water.

[0007] A lens-type submerged structure is, for example, a flat plate with a planar shape such as a convex lens type or a Fresnel lens type having a focal point, or a plurality of units assembled to have these shapes, and It was installed submerged in the sea across the direction.

Furthermore, an underwater protrusion installed in the ocean area near the focal point of a lens is an artificial underwater protrusion that protrudes from the seabed at and/or around the focal point of a lens-shaped submerged structure and is placed in a direction transverse to the wave direction. It is sufficient that the upper end of the structure or natural reef is located at a prescribed water depth, for example, 0.5 to 3.0 times the height of the increased wave passing through it.
It has various shapes such as a mound shape, a flat plate shape, a rectangular parallelepiped shape, and a rod shape. Also, the length in the direction perpendicular to the wave direction is
The length should be appropriately designed depending on the purpose of breaking waves, and for example, when used for surfing, it is preferably 20 to 30 m. These underwater protrusions are constructed according to the focal point of the submerged structure, but in the case of natural reefs, etc., the underwater projections are constructed based on these positions in order to locate them near the focal point. Submerged structures may be installed.

[0009]

[Operation] According to the present invention, waves that cross the lens-shaped submerged structure are refracted with a phase delay. The refracted waves concentrate toward the focal point of the lens and increase their wave height. The wave height increases further due to shallow water deformation caused by underwater protrusions located near the focal point of the lens, and the wave height exceeds the breaking limit wave height and breaks.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

As shown in FIGS. 1 and 2, the wave breaking facility of the present invention includes a submerged structure 10 of a convex lens type, and a focal point 1 of the submerged structure 10.
3 and a mound-like structure 20 as an underwater protrusion installed on the seabed at a position surrounding the structure.

The submerged structure 10 is constructed by assembling a large number of cylindrical members 11 with their axes substantially perpendicular to the wave direction It is fixed at a depth of water shallower than 1/2 wavelength of the wave crossing it by the connected and assembled support stand 12. The waves crossing the submerged structure 10 are refracted inward with a phase delay caused by the change in water depth, and are concentrated while increasing the wave height toward the focal point 13 of the submerged structure 10 as a convex lens. . As a result, the waves crossing the submerged structure 10 are
Near the focal point 13, the wave height becomes 2 to 5 times higher.

It should be noted that the submerged structure 10 in which the columnar member 11 is assembled reduces reflected waves and energy loss when waves cross, when compared to a submerged structure made of a flat plate or the like. Therefore, the wave collection efficiency can be improved. Also,
The submerged structure 10 to which the columnar member 11 is assembled may be moored at a predetermined depth of water without being fixed by an anchor member and a chain.

The mound-like structure 20 is constructed by piling up rubble from the seabed in the area surrounding the focal point 13, and its upper end is 0.5 of the wave height of the increased waves passing through it.
It is located at ~3.0 times the depth of the water, and the length in the direction perpendicular to the wave direction is 20 to 30 m. And submerged structure 10
The waves that concentrate while increasing the wave height toward the focal point 13 of
The wave height is further increased by the shallow water deformation caused by the mound-like structure 20, and the wave breaks beyond the wave breaking limit wave height.

[0015] In this way, the breaking waves that are actively obtained at a certain location, that is, near the focal point 13 of the submerged structure 10, have a large ridge height and are effectively used for leisure activities such as surfing.

FIGS. 3 to 5 show other embodiments of the underwater projection.

The underwater protrusion shown in FIG. 3 has a flat plate 21 fixed to the upper end of a support pile 22 driven into the seabed, and can be easily constructed and manufactured at low cost.

The underwater protrusion shown in FIG. 4 has a mound member 23 attached to the upper end of a jack 25 that is erected from a concrete foundation 24 built on the seabed. 25 and expand and contract the mound member 2.
The shape of the wave can be controlled by changing the water depth at which the upper end of the waveform 3 is located. Note that the submerged structure 10
Even if the height of waves crossing the mound member 23 is low, by making the water depth at the upper end of the mound member 23 shallow, waves can be reliably broken.

The underwater protrusion shown in FIG. 5 is constructed by towing a caisson 26 constructed on the ground and sinking it into the seabed, so that it can be easily installed even in deep sea areas.

[0020] In this embodiment, a case has been described in which underwater protrusions are provided to match the focal position of the submerged structure 10, but when using natural reefs etc., these should be placed at the focal position. , the position of the submerged structure 10 may be selected based on these, and the submerged structure 10 may be constructed.

[0021]

[Effects of the Invention] As described above, the wave breaking facility of the present invention consists of a lens-shaped submerged structure and an underwater protrusion installed in the sea area near the focal point of the submerged structure. After that, the waves that increase in height while concentrating are forcibly broken near the focal point by the action of underwater protrusions. Therefore, by obtaining high breaking waves at a certain location, it can be effectively used for leisure activities such as surfing. In addition, the energy of waves is dissipated by breaking waves, making the nearby sea area calmer.

Furthermore, by making the height of the underwater protrusion variable and changing the water depth at which its upper end is located, it is possible to control the shape of breaking waves and form waves more suited to the purpose. Furthermore, even waves with small heights can be broken, creating a calmer sea area.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing a wave breaking facility of the present invention.

FIG. 2 is a sectional view showing the wave breaking facility of the present invention.

FIG. 3 is a sectional view showing an example of an underwater protrusion constituting the wave breaking facility of the present invention.

FIG. 4 is a sectional view showing an example of an underwater protrusion constituting the wave breaking facility of the present invention.

FIG. 5 is a sectional view showing an example of an underwater protrusion constituting the wave breaking facility of the present invention.

[Explanation of symbols]

10 Submerged structures 13. Focus

Claims (1)

[Claims] 1. A wave breaking facility consisting of a combination of a submerged structure with a lens-shaped planar shape installed at a predetermined water depth based on the correlation with the wavelength of waves, and an underwater protrusion installed in the sea area near the focal point of the lens. .