JP3170649U - Tsunami breakwater - Google Patents

Abstract

The present invention provides a tsunami breakwater that is installed in a shallow sea area and attenuates tsunami energy to reduce tsunami damage on the coast. A plurality of levee bodies 10 and the like are provided in multiple stages in a shallow sea area so as to be spaced apart from each other to allow the passage of a ship and orthogonal to the traveling direction of a tsunami 50. The wall surface 10A on the side where the tsunami collides is formed in a side arc shape so as to bounce off the tsunami. Of the plurality of levee bodies, the dam body near the land is preferably bent in a direction in which both sides are separated from the land. [Selection] Figure 3

Description

  The present invention relates to a tsunami breakwater, and more particularly to a breakwater that is installed in a shallow sea area and attenuates tsunami energy to reduce tsunami damage on the coast.

  Since our country is surrounded by the sea on all sides, the tsunami damage at the time of the earthquake has been repeated. The tsunami has a tremendous amount of damage, including a sudden increase in wave height in shallow waters, ascending to the land (upward) with enormous energy, and destroying houses on the land. It is known that the tsunami wave height is very high not only in the narrow bay area but also in the shallow sea area.

  In areas where tsunami damage is a concern, tsunami run-up is suppressed, for example, by seawalls. The height of the seawall is determined from the wave height of past tsunamis, etc., but the height of the seawall is getting higher from the viewpoint of ensuring safety. Tend to be.

  On the other hand, there are tsunami breakwaters that are installed in multiple stages in shallow water so that the height of the tsunami that allows tsunami overtopping is perpendicular to the direction of the tsunami, so that the energy of the tsunami reaching the land is attenuated. It has been proposed (Patent Document 1).

  In addition, a levee body with an opening that allows a part of the tsunami to pass over the top surface is installed in a shallow sea area, and the bottom and side surfaces of the opening are roughened, and the energy of the tsunami reaching the land is attenuated by passing through the opening. Such a tsunami breakwater has been proposed (Patent Document 2).

Japanese Patent Laid-Open No. 07-113219 Japanese Patent Laid-Open No. 07-113216

  However, in the tsunami breakwater described in Patent Documents 1 and 2, the tsunami energy is attenuated by overtopping. Therefore, the tsunami energy cannot be attenuated so much for a huge tsunami. Damage cannot be reduced.

  In view of such problems, an object of the present invention is to provide a tsunami breakwater that can attenuate tsunami energy and reduce tsunami damage even if it is a huge tsunami.

  Therefore, the tsunami breakwater according to the present invention is provided in multiple stages so that a plurality of levee bodies allow mutual passage of the ship in a shallow sea area and are orthogonal to the traveling direction of the tsunami. The levee body has a levee height that can prevent the tsunami of the assumed wave height from overtopping, and the wall surface on the side where the tsunami collides is formed in a side arc shape so as to bounce off the tsunami.

  One of the features of the present invention is that a plurality of levee bodies are provided in multiple stages at intervals that allow a ship to pass, the height of each of the plurality of levee bodies is set to a sufficient height, and the wall surface is formed in a side arc shape. It is in the point.

  As a result, the tsunami that has traveled from offshore collides with the embankment and bounces off, collides with the next tsunami and cancels the energy of the tsunami. In addition, the tsunami that has traveled between adjacent levee bodies proceeds toward the next levee body. The same thing happens in the next levee. The tsunami energy gradually decreases as these functions are repeated, reducing the possibility of damage going up to land.

  Moreover, what is necessary is just to provide two or more levee bodies. In particular, if the shape of the dam body near the land is bent in the direction away from the land, the tsunami that collided with the dam body near the land and changed the direction of travel sideways was caused by the parts on both sides of the dam body. Since it is guided and travels away from the land, it is possible to further reduce the run-up to the land.

It is a schematic plan view which shows preferable embodiment of the tsunami breakwater which concerns on this invention. It is a figure which shows typically the effect | action in the said embodiment. It is a figure which shows typically the principal part in the said embodiment.

  Hereinafter, the present invention will be described in detail based on specific examples shown in the drawings. 1 to 3 show a preferred embodiment of a tsunami breakwater according to the present invention. In the figure, on the seabed shallower than the depth of 25 m of the bay 20, for example, a plurality of levee bodies 10 and 11 are substantially perpendicular to the tsunami traveling direction, and intervals W0 and W1 through which ships can pass each other are opened. The levee bodies 10 and 11 are provided with multi-stage lighting lamps (not shown) at both ends of the levee bodies 10 and 11, and on the land, between the sea and a building 13 such as a house. A seawall 12 is constructed.

  The levee body 10 drives the foundation pile 10B so as to reach the bedrock 31 below the seabed 30, and the levee body 10 uses, for example, reinforced concrete on the foundation pile 10B, and the height of the levee that can prevent the expected tsunami 50 from overtopping. Is formed. On the front wall surface of the levee body 10 is formed a side wall-arc concave wall surface 10A so as to sandwich the sea surface at the time of high tide, and it will rebound when a tsunami 50 having an assumed wave height collides.

  Further, the dam body 11 near the land is formed on a side arc-shaped concave wall surface similar to the dam body 10 and has a planar shape in which both side portions are bent forward, and a part of the collided tsunami 50 is obliquely forward. It is designed to send out.

  Further, behind the dam bodies 10, 11, stones are piled up so that seafood breeds to form a fish reef 10C, and a wave-dissipating block 10D is piled up so as to cover the fish reef 10C. It is made to collide with 10D and attenuate energy.

  When an earthquake occurs on the offshore seabed and the tsunami 50 rushes toward the bay 20, it collides with the first stage levee body 10. Then, the tsunami 50 collides with the arc-shaped concave wall surface 10 </ b> A of the levee body 10 and is bounced back, and the bounced wave 50 </ b> A collides with the tsunami 50 that pushes down and attenuates energy that pushes forward to the tsunami 50.

  On the other hand, the tsunami 50 traveling between the adjacent levee bodies 10 collides with the wall surface 10A of the next-stage levee body 10, and the tsunami energy is attenuated in the same manner as the tsunami 50 collided with the lowest-stage dam body 10. . Such a function is repeated, the energy of the tsunami 50 is greatly attenuated, and the wave height does not become so high.

  Even if the coastline is reached, since the seawall 12 is installed, the building 13 such as a house is rarely damaged.

  In this example, since both sides of the dam body 11 close to the land are bent forward, a part 50B of the tsunami 50 is guided to the side, and damage to the building 13 can be further reduced.

  In the above description, both sides of the dam body 11 near the land are bent forward, but they may be kept straight.

10, 11 Dike body 10A Side wall circular concave wall 20 Bay 50 Tsunami

Claims (2)

  In the shallow sea area, a plurality of levee bodies (10, 11) are provided in multiple stages so as to be spaced apart from each other to allow passage of the ship and orthogonal to the traveling direction of the tsunami (50). (10, 11) has an embankment height that can prevent the tsunami (50) of the assumed wave height from overtopping, and the wall surface (10A) on the side where the tsunami (50) collides is a side arc shape so as to bounce the tsunami. Tsunami breakwater characterized by being formed in.   The tsunami breakwater according to claim 1, wherein the dam body (11) near the land among the plurality is bent in a direction in which both sides are separated from the land.

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