JP5430641B2 - Tsunami breakwater and its layout - Google Patents

Description

  The present invention belongs to a technical field related to a tsunami breakwater that is installed in a coastal sea area and protects various facilities in a coastal area from a tsunami.

  Recently, it was understood that the energy of tsunamis (especially giant tsunamis) is extremely strong, and it is impossible to completely protect various facilities in coastal areas from tsunamis. For this reason, it was proposed that the tsunami breakwater should be structured so as to avoid the collapse of the tsunami, but to attenuate the tsunami energy as much as possible, but avoid the collapse. Yes.

  Conventionally, as a tsunami breakwater oriented to avoid the collapse of the tsunami energy that is attenuated as much as possible, for example, the one described in Patent Document 1 is known.

  Patent Document 1 describes a tsunami breakwater in which a plurality of (multi-stage) breakwater walls are installed in the direction of the tsunami flow so that the tsunami can overtop.

  The tsunami breakwater according to Patent Document 1 reduces the energy of the tsunami applied to the breakwater by preventing the tsunami from damming the breakwater without damming it and avoids the breakup of the breakwater. It is intended to attenuate the energy of the tsunami by changing the direction of the flow.

JP-A-7-113219

  The tsunami breakwater according to Patent Document 1 has a problem that the tsunami energy cannot be sufficiently attenuated because the direction change of the flow when the tsunami passes over the breakwater is small. In addition, although the caisson method is adopted, it cannot be installed unless a large-scale civil engineering work is performed on the seabed, resulting in an increase in installation cost.

  The present invention has been made in consideration of such problems, and the tsunami breakwater capable of sufficiently attenuating the energy of the tsunami with low installation cost and effectively functioning the tsunami breakwater in accordance with the coastal topography. It is an object of the present invention to provide an arrangement structure of a tsunami breakwater that can be made.

  In order to solve the above-described problems, the tsunami breakwater according to the present invention employs the means described in claims 1 to 4 of the claims.

  That is, according to the first aspect of the present invention, there is provided a breakwater wall formed of a metal material having an inclined guide surface that is installed on the bottom of the coastal sea area and guides a tsunami flow from the offshore to the coastal area upward. The wall is formed of a metal material in a frame shape and is supported by an installation frame fixed to the seabed.

  By this means, the construction of large-scale civil engineering work on the sea floor during installation is unnecessary by supporting the breakwater wall made of metal material on the installation frame formed in the shape of a metal frame and fixed on the sea floor. To do. Further, since the wave barrier has an inclined guide surface that guides the tsunami flow upward, the tsunami flow is largely redirected upward in the wave barrier.

  According to a second aspect of the present invention, in the tsunami breakwater according to the first aspect, the guide surface of the breakwater wall has a curved shape facing the concave shape with respect to the flow of the tsunami.

  In this means, since the guide surface of the wave preventing wall has a curved shape, the upward direction change of the tsunami flow becomes a curved shape.

  Further, in claim 3, in the tsunami breakwater according to claim 1 or 2, the guide surface of the breakwater guides upward the flow of tsunami as a tsunami heading offshore from the coastal area. To do.

  In this means, since the guide surface of the breakwater wall also corresponds to the flow of the tsunami as a wave, it is possible to deal with a huge tsunami that has strong energy in both the push wave and the wave.

  According to a fourth aspect of the present invention, in the tsunami breakwater according to any one of the first to third aspects, the breakwater wall is installed in a stepped manner in a plurality of steps so as to further guide the flow of the tsunami guided upward. It is characterized by that.

  In this means, the tsunami flow can be changed in a larger upward direction by installing the wave barriers in a stepped manner with a plurality of steps.

further,
In order to solve the above-described problem, the arrangement structure of the tsunami breakwater according to the present invention employs the means described in claim 5 of the claims.

  That is, in Claim 5, it arrange | positions in the mountain shape which becomes convex toward the bay outside so that the bay mouth of the bay which penetrated deeply into two or more embankments may be plugged up without continuing the tsunami breakwater in any one of Claims 1-4. It is characterized by that.

  In this method, the tsunami breakwater is not formed as a continuous long body, but is placed in a mountain shape that protrudes outward from the bay so as to close the bay mouth where multiple dams are deeply inserted. A part of the tsunami flow is diverted to the side.

  The tsunami breakwater according to the present invention supports a large-scale civil engineering work on the seabed at the time of installation by supporting a breakwater wall made of a metal material on an installation frame formed in a frame shape with a metal material and fixed to the seabed. Since the construction is unnecessary, the installation cost is reduced. In addition, since the wave barrier has an inclined guide surface that guides the tsunami flow upward, the tsunami flow is largely redirected upward in the wave barrier, so the tsunami energy is sufficiently attenuated. There is an effect that can be done.

  Further, as claimed in claim 2, since the guide surface of the wave breaker has a curved shape, the upward direction change of the tsunami flow becomes a curved shape, so that the upward direction change of the tsunami flow is made smoothly. There is an effect.

  Further, as claimed in claim 3, it is possible to cope with a huge tsunami having strong energy both in the pushing wave and the waving wave by the guide surface of the breakwater wall corresponding to the tsunami flow as the waving wave. Therefore, the energy of the huge tsunami can be sufficiently attenuated.

  In addition, as claimed in claim 4, since the wave barriers are installed in a stepped manner with a plurality of steps, the flow of the tsunami can be redirected more greatly upward, so that the energy of the tsunami can be more sufficiently attenuated. There is an effect that can be done.

  Furthermore, the tsunami breakwater according to the present invention should be arranged in a mountain shape that protrudes toward the outside of the bay so as to close the bay entrance of the bay where multiple tsunamis are deeply inserted without making the tsunami breakwater a continuous long body. In order to divert part of the tsunami flow to the side of the tsunami breakwater arrangement, the tsunami breakwater can be reliably prevented from collapsing by reducing the energy of the tsunami on the tsunami breakwater in the deeply entering bay. There is an effect that the energy of the divided tsunami can be continuously attenuated by the adjacent tsunami breakwater.

It is a perspective view of the 1st example of the form for implementing the tsunami breakwater which concerns on this invention. It is a longitudinal cross-sectional view of FIG. It is sectional drawing of the 2nd example of the form for implementing the tsunami breakwater which concerns on this invention. It is a 3rd sectional view of the form for carrying out the tsunami breakwater concerning the present invention. It is a top view of the form for implementing the arrangement structure of the tsunami breakwater which concerns on this invention.

  EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing the tsunami breakwater which concerns on this invention, and its arrangement structure is demonstrated based on drawing.

  First, the form for implementing the tsunami breakwater which concerns on this invention is demonstrated.

  1 and 2 show a first example of an embodiment for implementing a tsunami breakwater according to the present invention.

  The first example includes an installation frame 1 and a wave barrier 2.

  The installation frame 1 is formed in a frame shape with a metal material such as a steel material whose surface is anticorrosion-treated, and a horizontal frame 12 is assembled in a bowl shape above the vertical frame 11.

  The wave-breaking wall 2 is formed in a hollow shape with a metal material such as a steel plate whose surface is corrosion-resistant, and is assembled into a deformed box shape with the bottom plate 21, the top plate 22, the end plate 23, and the side surface 24. Yes. As the cross-sectional shape of the wave preventing wall 2, two types are provided as shown in FIG. In one type, one of the side plates 24 is a curved guide surface 24a that is concave toward the outside, and the other is a flat plate surface 24b that is vertical. Another type is a curved guide surface 24a in which both side plates 24 are concave outward. The curved shape of the guide surface 24a is a curvature that can increase the flow of the tsunami W from the bottom plate 21 side to the top plate 22 side, and the abruptness that returns the tsunami W toward the offshore at the upper part. It is considered as curvature.

  One type of wave barrier 2 is supported by fixing end plates 23 to the vertical frame 11 and the horizontal frame 12 of the installation frame 1 by welding or the like so that the bottom plate 21 is attached to the seabed E, The guide surface 24a is provided at the front and rear (left and right in FIG. 2) end portions of the installation frame 1 facing the outside. The other one type of wave barrier 2 is supported by a bottom plate 21 fixed to the central portion of the horizontal frame 12 of the installation frame 1 by welding or the like. That is, the wave barrier 2 is installed in a stepped manner with a plurality of steps.

  The breakwater wall 2 supported by the installation frame 1 is fixed and installed on the seabed E in the coastal sea area by driving a part of the vertical frame 11 of the installation frame 1 into a long length and driving it into the seabed E. Preferably, the height of the bank is set so that the horizontal frame 12 of the installation frame 1 and a part of the upper part of the wave barrier 2 are exposed from the sea surface F.

  According to the first example, in the installation, it is not necessary to perform civil engineering work such as large foundation work on the seabed E. Therefore, the installation cost is reduced.

  When the first example is installed on the seafloor E in the coastal sea area, when the tsunami W heading from the offshore to the coastal area rushes, the flow of the tsunami W flows into the bottom breakwater 2 as shown in FIG. It is guided upward by the guide surface 24a. As a result, the flow of the tsunami W in the breakwater wall 2 is redirected much higher than the tsunami breakwater according to Patent Document 1, and the energy of the tsunami W is sufficiently attenuated. Moreover, the large direction change of the flow of the tsunami W reduces the energy of the tsunami W applied to the wave barrier 2 and the installation frame 1, and the collapse of the wave barrier 2 and the installation frame 1 can be avoided.

  Furthermore, the flow of the tsunami W guided upward by the lower wave barrier 2 is again guided upward by the guide surface 24 a of the upper wave barrier 2. As a result, the flow of the tsunami W is further redirected upward, and the energy of the tsunami W is more sufficiently attenuated.

  In addition, the wave barrier 2 on the opposite side of the front and rear corresponds to the flow of the tsunami W as a pulling wave from the coastal region to the offshore. That is, the operation of the state illustrated symmetrically with FIG. Accordingly, since it is possible to deal with a giant tsunami W having strong energy both in the push wave and in the pull wave, the energy of the giant tsunami W can be sufficiently attenuated.

  FIG. 3 shows a second example of a mode for carrying out the tsunami breakwater according to the present invention.

  In the second example, as the cross-sectional shape of the wave barrier 2, one type that is the wave barrier 2 in the upper stage of the first example is provided.

  According to the second example, the flow of the tsunami W that has waved over without being guided upward by the front wave barrier 2 at the lower stage is guided upward by the wave barrier 2 at the rear side of the lower stage. Further, the flow of the tsunami W guided upward by the rear breaker wall 2 collides with the flow of the tsunami W descending over the upper breaker wall 2. Accordingly, the energy of the tsunami W is further sufficiently attenuated.

  FIG. 4 shows a third example of an embodiment for carrying out the tsunami breakwater according to the present invention.

  In the third example, a wave barrier 2 is supported in three stages on an installation frame 1 fixed to the seabed E with an anchor structure 3.

  In the anchor structure 3, a wave preventing material 32 that makes the wave preventing wall 2 smaller is attached to the front and rear surfaces of a small anchor main body 31 made of concrete constructed on the seabed E. A part of the vertical frame 1 of the installation frame 1 is fixed to the anchor main body 31.

  Of the three-stage wave barriers 2, the middle wave break wall 2 is provided with a guide surface 24a formed in a thin box shape and formed of an inclined surface, and is slid along an extended line of the inclination. The installation frame 1 is provided with a tower 4 that houses a drive unit (not shown) that slides up and down the middle wave barrier 2.

  According to the third example, since it is larger than the first example and the second example, it can be used as a leisure facility. The installation frame 1 is fixed to the seabed E by the anchor structure 3 in response to the increase in size. However, since the anchor structure 3 is small, civil engineering work such as large-scale foundation work on the seabed E is possible. Never needed.

  For the other points, the same effects as in the first and second examples can be obtained, but the resistance to the wind can be reduced by lowering the middle-stage wave barrier 2 only when the tsunami is pushed. And unnecessary damage under strong winds can be avoided.

  Next, the form for implementing the arrangement structure of the tsunami breakwater which concerns on this invention is demonstrated.

  FIG. 5 shows a form for carrying out the arrangement structure of the tsunami breakwater according to the invention.

  In the first example, the tsunami breakwater B described above is not continuous, but the guide surface 24a of the breakwater wall 2 is turned offshore as a plurality of rectangular revetments, and the bay entrance of the bay G that has entered deeply is blocked. It is arranged in multiple steps in a mountain shape that protrudes toward the outside of the bay.

  Further, a plurality of tsunami breakwaters B are connected in a mountain shape, and a plurality of tsunami breakwaters B are connected in a planar step shape, and the whole is arranged in a mountain shape.

  According to this form, in addition to the energy being attenuated when the tsunami W crosses the tsunami breakwater B as described above, a part of the flow of the tsunami W is diverted to the side of the Yamagata arrangement of the tsunami breakwater B. Is done. As a result, in the bay G that has entered deeply, the energy of the tsunami breakwater B is reduced by reducing the energy of the tsunami breakwater B, and the collapse of the tsunami breakwater W is surely prevented. Furthermore, it can attenuate continuously. In addition, the entire flow of the tsunami W can be actively guided to the vicinity of the cliff at the mouth of the bay, and the arrival of the energy of the tsunami W into the bay G that has entered deeply can be effectively reduced. Therefore, the arrival of the energy of the tsunami W into the bay G that has entered deeply can be effectively reduced.

  As described above, in addition to the illustrated examples, the planar shape of the tsunami breakwater B can be other than a rectangle.

1 Installation frame 11 Vertical frame 12 Horizontal frame 2 Breakwater 24a Guide surface E Sea floor W Tsunami G Bay

Claims (5)

  Installed on the seafloor in the coastal sea area, it has a wave-breaking wall made of metal with an inclined guide surface that guides upward the flow of tsunami from the offshore to the coastal area. A tsunami breakwater that is supported by an installation frame that is formed on the bottom of the sea.   2. The tsunami breakwater according to claim 1, wherein the guide surface of the breakwater has a curved shape facing the concave shape with respect to the flow of the tsunami. The tsunami breakwater according to claim 1 or 2, wherein the guide surface of the breakwater guides upward also the flow of tsunami as a pulling wave heading offshore from the coastal area.   The tsunami breakwater according to any one of claims 1 to 3, wherein the breakwater wall is installed in a plurality of steps in a stepped manner so as to further guide the flow of the tsunami guided upward. .   A tsunami characterized by being arranged in a mountain shape that protrudes outward from the bay so as to close the bay entrance of the bay where a plurality of dams are deeply inserted without continuing the tsunami breakwater of any one of claims 1 to 4 Breakwater arrangement structure.

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