JPH02112512A - Wave dissipation submerged dike - Google Patents

Abstract

PURPOSE:To enhance the effect of wave dissipation, to prevent the erosion of the seashore and to purify sea-water by filling filler to the inside of a box consisting of side plates provided with a tip-board, bottom-board and opening and a side plate connecting to the side plates to construct a wave dissipation submerged dike. CONSTITUTION:A wave dissipation submerged dike 1 filled with filler 2 to the inside of a hollow box consisting of having required lengths of an inclination and inclined direction with a projection 12 thereon, if desirable, a bottom board 13, side plates 14 and 14 provided with an opening 15 connected the top-board 11 to the bottom board 13 and a side plate blocking between the side plates 14 and 14 is formed. Incoming wave (A) is broken up into permeable wave (C) passing through the top board 11 and permeable wave (D) passing through rubble mount 3 and the side plate 14 by placing the submerged breakwater 1 under the water, an reflection wave (B) coupled with the projection 12 is reduced. Furthermore, the permeable wave (C) is damped, and an organism is oxidized and degradated by seaweed and micro-organisms adhered to the filler 2 to purify sea-water.

Description

[Detailed Description of the Invention] <Prior Art> As a conventional wave-dissipating structure, there is an offshore breakwater that is constructed by stacking concrete blocks and has both a certain degree of wave-dissipating effect and beach nourishing effect.

<Problems to be Solved by the Present Invention> The following problems exist in the above-described conventional wave-dissipating technology using offshore breakwaters.

(a) When the depth of water increases, the volume of materials such as concrete blocks becomes large, making detached breakwaters uneconomical.

(b) The detached levee is likely to collapse due to scouring and waves in front of the detached levee.

(c) The upper part of the breakwater protrudes above the sea surface to enhance the wave-dissipating effect.

Therefore, there is a risk of damaging the landscape.

<Objective of the present invention> The present invention was made to solve the above-mentioned problems, and it not only makes it possible to obtain a sufficient wave-dissipating effect and create a calm sea area, but also makes it possible to prevent coastal erosion. The purpose of this project is to provide a wave-dissipating submersible with a seawater purification function.

Configuration of the Present Invention> An embodiment of the present invention will be described below with reference to the drawings.

<B> Overall structure The wave-dissipating submerged levee 1 of the present invention has a hollow space formed by a top plate 11 and a bottom plate 13 made of concrete or the like, a side plate 14 having an opening 15, and a side plate 16 connecting the side plates 14. This is a box body, and the filling material 2 is stuffed inside this box body.

<Exposure> Top plate The top plate 11 is a plate attached to the top surface of the submerged embankment 1 at an angle.

The angle of inclination and the length in the direction of inclination of the top plate 11 are selected at any time depending on the installation position of the submerged embankment 1 and the desired wave-dissipating effect.

Further, it is preferable to provide a protrusion 12 protruding from the upper surface of the top plate 11 in a direction perpendicular to the direction of inclination of the top plate 11 to promote wave breaking.

The installation position and number of the projections 12 are selected at any time depending on the desired wave-dissipating effect.

<C> Side plate The side plate is a plate that connects the top plate 11 and the bottom plate 13, and is composed of a side plate 14 and a side plate 16.

The side plates 14 are attached to both ends of the top plate 11 in the inclined direction,
A plurality of openings 15 are opened.

The size and number of the openings 15 are not so large as to reduce the strength of the side plate 14, and are opened to the extent that incoming waves can pass through the submerged levee 1.

Therefore, seawater flowing in through the opening 15 in one side plate 14 can flow out through the opening 15 in the other side plate 14 .

The side plates 16 are plates that close both ends of the top plate 11 of the submerged levee 1 in a direction perpendicular to the inclination direction.

<2> Filling material The filling material 2 is a block of stone or the like filled inside the submerged embankment 1 configured as described above.

The type and particle size of the filling material 2 are such that the incoming waves can pass through the submerged levee 1, and the filling material 2 is such that it can penetrate into the gap in the filled state.
It shall be such that algae, shellfish, crustaceans, microorganisms, etc. can propagate appropriately.

<E> Installation method First, the seabed surface on which the submersible levee 1 will be installed is leveled.

Next, as shown in FIG. 2, the submerged embankment 1 is installed so that the side plate 14 attached to the lowest side of the top plate 11 is orthogonal to the direction of incidence of the incident wave A.

Then, on the oil side and the shore side of the submerged embankment 1, coarse rubble 3 and the like that are permeable to seawater are piled up to anchor the submerged embankment 1.

At this time, the rubble 3 on the oil side should be built low since it is necessary to sufficiently expose the opening 15 of the side plate 14, and on the shore side it is preferable to build it to the same height as the side plate 14.

<Effect> Next, the operation of the present invention will be explained.

<B> Effect of reducing reflected waves Since the entire structure of the submerged levee 1 of the present invention is submerged under the water surface, a part of the incident wave A is transmitted through the upper surface of the top plate 11 (as shown by arrow C).
).

Moreover, since the side plate 14 is a permeable wall, seawater can pass through from inside the submerged levee 1 (arrow D).

Therefore, a part of the incident wave A is dispersed into the transmitted wave C(!:D), and the energy is dissipated in this process, thereby reducing the energy of the reflected wave B reflected to the oil side.

The present invention also provides a transmitted wave C that passes through the top plate 11 of the submerged levee 1.
Then, the transmitted waves passing through the rubble 3 and the side plate 14 can be dissipated as follows.

Exit> Wave dissipation of transmitted waves by the top plate The energy of the transmitted waves C transmitted to the shore side over the top surface of the top plate 11 is due to the fact that the top plate 11 is tilted upward toward the shore side. The energy of the transmitted wave C is gradually concentrated.

Therefore, the transmitted wave C with concentrated energy cannot maintain a stable shape and is forcibly broken.

Therefore, the transmitted wave C can be attenuated by the top plate 11.

Further, by providing the protrusions 12 on the upper surface of the top plate 11 to increase the surface roughness, it is possible to enhance the wave-dissipating effect of the transmitted waves C.

<C> Wave dissipation effect of the transmitted waves by the side plates and the filling material The energy of the transmitted waves transmitted to the shore side through the gap between the opening 15 of the side plate 14 on the extension side and the shore side and the filling material 2 is The energy is attenuated by the frictional resistance when seawater flows through the gap in the filling material 2 and by the turbulence of the water flow within the gap.

Therefore, the transmitted wave C can be attenuated by the side plate 14 and the filling material 2.

<2> Purification effect When seawater passes through the gaps in the filling material 2, organic matter in the seawater is oxidized and decomposed by algae, shellfish, crustaceans, microorganisms, etc. attached to the filling material 2, so the seawater is purified. be done.

Furthermore, due to the aeration effect caused by forced wave breaking on the submerged levee 1, the amount of dissolved oxygen in the seawater increases, further promoting the purification of the seawater.

<Effects of the Present Invention> Since the present invention has been described above, the following effects can be expected.

<A> Conventional offshore breakwaters are prone to collapse due to scouring and waves in front of the breakwater.

In contrast, the present invention has a submerged embankment structure in which the entire structure is submerged below the water surface, so that a portion of the incident waves are transmitted through the top surface of the top plate.

Furthermore, since the collapsed plate is a transparent wall, it can be penetrated even from inside the submerged embankment.

Therefore, the incident wave is dispersed into the two transmitted waves, and the energy of the reflected wave reflected on the extension side is reduced by the amount of energy dissipated.

Therefore, scouring in front of the submerged embankment and collapse due to waves can be prevented.

<Exposure> Conventional offshore breakwaters are uneconomical as the water depth increases, as the volume of materials such as concrete blocks increases.

However, since the submerged embankment of the present invention is formed by a hollow box, the volume of materials such as concrete can be small, making it economical.

<C> When seawater passes through the gaps in the filling material, algae, shellfish, crustaceans, microorganisms, etc. attached to the filling material oxidize and decompose organic matter in the seawater, and the submerged seawater of the present invention Can be purified.

Furthermore, due to the aeration effect caused by forced wave breaking on the submerged levee,
It can increase the amount of dissolved oxygen in seawater and further promote seawater purification.

(2) The submerged embankment of the present invention can reduce the energy of the reflected waves that are reflected toward the extension side as described above, and can also dissipate the transmitted waves that pass through the top plate and the side plates.

That is, the energy of the transmitted waves transmitted over the top surface of the top plate to the shore side is gradually concentrated because the top plate is inclined upward toward the shore side.

Therefore, the transmitted waves with concentrated energy cannot maintain a stable shape, and are forcibly broken and attenuated.

In addition, the energy of the transmitted wave transmitted to the shore through the openings in the side plates on the extension side and the shore side and the gap in the filler material is due to the frictional resistance when seawater flows through the gap in the filler material. Energy is attenuated by the turbulence of ocean currents within the gap.

As described above, the submerged embankment of the present invention dissipates a part of the energy of the incident wave and returns it to the egress side as a reflected wave, and the remaining transmitted wave is effectively absorbed by the top plate, side plates, and filling material. It can be dissipated and dissipated.

Therefore, the wave-dissipating effect can be significantly improved.

<E> In the submerged embankment of the present invention, an incident wave is dispersed into a reflected wave and a transmitted wave, and the energy of the reflected wave reflected on the extension side is reduced by the amount of energy dissipated.

Therefore, since duplicate waves are not generated due to reflected waves, there is no adverse effect on ships etc. sailing nearby.

<f> The upper part of conventional offshore breakwaters protrudes above the sea surface to enhance the wave-dissipating effect, which may spoil the scenery.

However, since the present invention is a submerged embankment structure in which the entire structure is submerged under water, there is no risk of spoiling the scenery.

<G> By increasing the surface roughness by providing protrusions on the upper surface of the top plate, the wave-dampening effect of the transmitted waves can be further enhanced.

<H> Since the entire structure of the submerged levee of the present invention is one piece, it has excellent stability against wave force and is free from the risk of being destroyed unlike conventional offshore levees.

[Brief explanation of the drawing]

Fig. 1 2 An explanatory diagram of an embodiment of the present invention Figure 2: Detailed illustration of the present invention

Claims (2)

[Claims] (1) In a submerged levee that dissipates waves by sinking the entire structure below the water surface, it is a hollow box formed by a top plate, a bottom plate, and a side plate, the top plate having a predetermined angle of inclination, and the top plate having a predetermined angle of inclination. An extinguisher consisting of transparent side plates with openings attached to both ends of the board in the direction of inclination, closed side plates attached to both ends of the top plate in the direction perpendicular to the direction of inclination, and filling material filled inside the box body. Wave dike. (2) Claim 1, in which a projection is provided on the top surface of the top plate
Wave-dissipating submerged embankment as described in section.