JP2012197553A - Breakwater unit and floating type breakwater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low-cost breakwater unit and breakwater which demonstrate a breakwater function only when a tsunami or the like occurs and are easy to construct and maintain.SOLUTION: The breakwater unit of this invention comprises a set of columns which can be freely housed at a water bottom and projected, a lifting body attached to the set of columns and mounted on the water bottom, and a set of breakwater plates freely turnably pivoted to the lifting body. By introducing buoyancy to the lifting body, the columns and the lifting body are floated, and the breakwater plate is erected from the state of being fallen down at the water bottom.

Description

  The present invention relates to a wave breaker unit and a levitated breakwater, and more specifically, a wave breaker unit that is normally placed on the bottom of the water and can stand up and exhibit a wave breaker function when a tsunami or storm surge occurs. And levitation breakwater.

The breakwater provided to prevent the intrusion of tsunamis and storm surges (hereinafter simply referred to as “tsunamis”) is generally a structure made of concrete or steel.
When constructing a breakwater with a structure made of concrete or steel, not only is it costly to install, but the breakwater will be installed on the sea constantly, which may hinder the operation of the ship, The surrounding environment may be affected by disturbing the landscape or changing the ocean current.

  In order to solve the above-described conventional problems, the invention described in Patent Document 1 or 2 below has been proposed as a breakwater that can exhibit a wave-breaking function only when a tsunami or the like occurs.

  For example, the movable breakwater described in Patent Document 1 has an outer diameter larger than the width of the gap on the outer bay side of the gap formed between the levitated steel pipe and the adjacent levitated steel pipe, and is suspended by a connector. A configuration including a suspended cylinder is disclosed.

  In addition, the movable breakwater described in Patent Document 2 is disclosed with a configuration including a plurality of breakwater floats that can float above the revetment outer wall by the buoyancy of water stored between the first inner wall surface and the second inner wall surface. Yes.

JP 2010-007355 A Japanese Patent Laid-Open No. 2006-070536

However, the above-described prior art has at least one of the following problems.
(1) In the movable breakwater described in Patent Document 1, it is necessary to uniformly feed air into all the pipes, and the structure of the air feed pipe becomes complicated. In addition, since the air supply is performed at the lower part of the pipe below the sea floor, maintenance of the air supply pipe and the like cannot be performed. In addition, large-scale seabed drilling is required to store all the pipes.
(2) In the movable breakwater described in Patent Document 2, since the tsunami breakwater operates only after the tsunami reaches the breakwater position, the tsunami has already reached the coastal area when the breakwater surfaced, causing damage. Expected. Also, if the facility is installed offshore, it will hinder vessel operation and aesthetics.
(3) Since both the upper steel pipe of Patent Document 1 and the wave-breaking float of Patent Document 2 need to form a continuous wall, the amount of drilled holes in the water bottom becomes excessive.
(4) Since both the upper steel pipe of Patent Document 1 and the breakwater float of Patent Document 2 need to perform rigidity calculation as a cantilever beam, in order to ensure rigidity sufficient to withstand tsunamis, There is a limit to the reduction of usage, and there is still room for improvement from the viewpoint of cost reduction.

  That is, an object of the present invention is to provide a breakwater unit and a breakwater that exhibit a breakwater function only at the time of occurrence of a tsunami or the like, and are simple and low in construction and maintenance.

The first invention of the present application, which has been made to solve the above-mentioned problems, is a set of struts that can be stored and projected on the bottom of the water, a lifting body that is attached to the pair of struts and placed on the bottom of the water, and the lifting body. And a pair of wave breakers that are pivotally supported in a pivotable manner, and by introducing buoyancy to the lifting body, the struts and the lifting body are levitated, and the wave blocking plate is collapsed at the bottom of the water. The present invention provides a wave-breaking unit characterized in that it stands up from.
Further, according to a second invention of the present application, in the above invention, the elevating body is composed of a top plate and a side wall extending downward from an outer edge of the top plate, and gas is contained in a space surrounded by the top plate and the side wall. The buoyancy is obtained by storing the water.
The third invention of the present application is characterized in that, in the above invention, a gas introducing device is installed at a water bottom position below the elevating body.
The fourth invention of the present application is characterized in that, in the invention described above, the support column is a columnar body configured to be slidable in an outer cylinder embedded in a water bottom.
The fifth invention of the present application provides a levitated breakwater that is formed by connecting a plurality of the breakwater units described above.

According to the present invention, at least one of the following effects can be obtained.
(1) Normally, since each member constituting the breakwater is stored on the bottom or bottom of the water, problems such as hindering the operation of the ship and affecting the ocean current do not occur.
(2) Since the floating structure of the floating body is simple, a breakwater can be constructed at a very low cost. In addition, since maintenance is good, maintenance costs are not excessive.
(3) Since it is not necessary to provide a floating pipe in the form of a continuous wall as compared with a conventional floating breakwater, the amount of drilling at the bottom of the water can be reduced.
(4) When a tsunami or the like occurs, the wave breaker plate stands up with two points supported, so that the same rigidity is ensured while reducing the amount of rigid material used compared to the conventional cantilever structure of a breakwater. Can be economical.
(5) Since the wave preventing plate resists a tsunami or the like, it is not necessary to provide a rigidity enough to resist the tsunami with a single support column, and the cost can be reduced by reducing the number of columns installed or reducing the size.
(6) When the standing wave-breaking plate receives a tsunami, the wave-breaking plate is pushed backward with water pressure, and the wave-breaking plate is tightly fixed between the lifting body and the bottom of the water. The wave-proof function can be demonstrated reliably.
(7) Since the breakwater can be deployed and stored by repeated introduction and release of buoyancy, operation training can be carried out easily.
(8) In extending the breakwater, it is only necessary to continue to connect the breakwater units, and the work is easy.

The schematic perspective view of the Example of the floating type breakwater of this invention. The schematic side view which shows the state at the time of the normal of the wave-proof unit which concerns on FIG. The schematic side view which shows the state at the time of the operation | movement of the wave-proof unit which concerns on FIG.

  The floating breakwater of the present invention will be described with reference to the drawings.

<1> Overall Configuration With reference to FIGS. 1 and 2, the configurations of the wavebreak unit and the floating breakwater of the present invention will be described.
The floating breakwater A of the present invention is formed by connecting a plurality of wavebreaking units B with a connecting material C such as a mooring fence.
The wave-breaking unit A includes a set of support columns 1 that can be stored with a space in the bottom of the water, a lift body 2 that is attached to the set of support pillars 1 and floats and sinks by the introduction of buoyancy, and is attached to the lift body 2. It includes at least a wave-breaking plate 3 pivotally supported.

<2> Column The column 1 is a member for supporting the lifting body 2 and the wave preventing plate 3.
The strut 1 can be a hollow or solid longitudinal member. The strut 1 is configured to be slidable inside the outer cylinder 4 embedded in a hole formed in the bottom of the water, so that the strut 1 can be stored in the bottom of the water or underwater. Can be exposed.
The length of the support column 1 is set in accordance with the water depth expected due to the occurrence of a tsunami or the like.
Note that “a set of support columns” is not limited to a plurality of support columns, and the number of support columns 1 may be one or more with respect to a certain lifting body 2, and the number required for strength calculation may be appropriately selected. That's fine.
In addition, what is necessary is just to provide a predetermined space | interval when installing two or more support | pillars.

[Retaining mechanism]
In addition, it is desirable to provide a retaining mechanism between the support column 1 and the outer cylinder 4 so that the support column 1 does not come out of the outer cylinder 4 completely. As an example of the retaining mechanism, there is a combination of a flange portion 11 provided at the lower end of the support column 1 and a stopper 41 provided at the upper end of the outer cylinder 4 (FIG. 2). When the support column 1 is pulled up by a predetermined length, the flange portion 11 interferes with the stopper 41 provided in the outer tube 4 so that the entire support column 1 does not come out of the outer tube.

<3> Lifting body The lifting body 2 sinks to the bottom of the water by its own weight, or obtains buoyancy and floats on the surface of the water so as to raise and lower the support column 1 and to erect or lie down the wave-breaking plate 3. It is a member.

[Constitution]
The elevating body 2 needs to have a configuration that allows the introduction and release of buoyancy, and more specifically, a configuration that can store and discharge gas.
For example, the elevating body 2 can be shaped like an empty rectangular parallelepiped with no bottom surface with the top plate 21 and the side wall 22 suspended downward from the outer edge of the top plate 21 (FIG. 2).
What is necessary is just to obtain | require the internal volume of the space enclosed by the said top plate and the side wall from the required buoyancy calculated based on the size of each structural member calculated | required from the water depth estimated by generation | occurrence | production of a tsunami etc.
When gas is introduced from below the lifting body, the gas is stored in a part of the space (storage space 23) surrounded by the top plate and the side wall, and the lifting body obtains buoyancy and floats on the water surface. Can do.

[Gas introduction device]
If the gas introduction device 5 for introducing gas into the storage space 23 is installed at a position where the raising / lowering body of the bottom of the water covers, the gas released from the gas introduction device 5 is easily stored in the storage space 23. .
Further, by fixing the gas introducing device 5 to the bottom of the water, for example, the introducing pipe follows the elevating body as compared with a structure in which the elevating body 2 itself is constituted by a floating bag and the gas introducing pipe is directly connected. As a result, it is possible to expect a reliable guarantee of operation without causing malfunctions or causing any interference by repeating ups and downs.

[Exhaust mechanism]
Moreover, it is necessary to provide the raising / lowering body 2 with the exhaust mechanism for extracting the gas stored inside the raising / lowering body (not shown).
The exhaust mechanism is provided with an openable / closable exhaust port on, for example, a top plate or a side wall, and the closing / opening of the storage space can be controlled by opening / closing the exhaust hole.

<4> Wavebreaker The wavebreaker 3 is a member for resisting a tsunami or the like while standing in water.

[Constitution]
The wave preventing plate 3 is attached to the front side (the side where the tsunami etc. comes) and the back side (the wave preventing object side) of the lifting body 2.
The upper portions of the front-side wave preventing plate 3a and the rear-side wave preventing plate 3b are pivotally supported by the elevating body 2 with the left-right direction of the elevating body (the laying direction of the wave-proof unit) as a rotation axis. By the above-mentioned shaft support, the wave preventing plate 3 can be rotated in the front-rear direction.
If the length of the wave-breaking plate 3 is set to be slightly longer than the water depth expected due to the occurrence of a tsunami or the like, the wave-breaking plate 3 is leaned against the lifting body 2 during operation. In general, it should be about 1.2 times the length of the sum of the normal water depth and the expected tsunami height.

[Other configurations]
Note that the back side wave barrier plate 3b may be meshed on the entire surface from the viewpoint of weight reduction and easy removal of tide.

<5> How to Use (a) Normal Time With reference to FIG. 2, the normal state of the wave preventing unit will be described.
The elevating body 2 is in a state of being placed on the water bottom by its own weight, and the storage space 23 inside the elevating body 2 is in a state filled with water.
The support column 1 is in a state of being housed in an outer cylinder 4 provided on the bottom of the water.
The wave preventing plates 3 a and 3 b are in a state where they lie down around the lifting body 2.

(B) During operation With reference to FIG. 3, the state during operation of the wavebreaking unit will be described.
When a tsunami or the like occurs, gas introduction is started using the gas introduction device 5.
The gas is gradually accumulated in the storage space 23 inside the elevating body 2, and when a certain amount of gas is stored, the elevating body 2 floats on the water.
At this time, each support | pillar 1 attached to the raising / lowering body 2 is extracted from the outer cylinder 4, respectively, and raises. When the support column 1 is pulled up by a predetermined length, the flange portion 11 interferes with the stopper 41 provided in the outer tube 4, so that the entire support column 1 does not come out of the outer tube.
As the elevating body 2 floats, the wave-breaking plate 3 that is pivotally supported gradually rises from the lying down state. When the elevating body 2 is completely lifted, the lower end of the wave preventing plate 3 is located in a state where the lower end of the wave preventing plate 3 is slightly inclined forward, and the top plate 21, both the wave preventing plates 2, and the water bottom form a substantially trapezoidal cross-sectional shape.
At this time, since the upper surface of the top plate 21 of the elevating body 2 is exposed on the water, the operation can be confirmed visually.

(C) At the time of arrival of tsunami etc. The state at the time of arrival of the tsunami etc. of a wave-proof unit is demonstrated referring FIG.
When a tsunami or the like arrives, it resists the tsunami or the like with the front surface of the wave preventing plate 3.
At this time, since the front side wave breaker plate 3a is pushed into the rear side, the lower end of the wave breaker plate 3a is pushed further into the water bottom, and the wave breaker plate 3a is more firmly fixed between the elevating body 2 and the water bottom. Therefore, a reaction force that resists tsunami and the like can be obtained from the bottom of the water.

A Floating breakwater B Breakwater unit C Connecting material 1 Post 2 Lifting body 21 Top plate 22 Side wall 23 Storage space 3 Wavebreak plate 4 Outer cylinder 5 Gas introduction device

Claims (5)

A set of struts that can be stored and projected on the bottom of the water,
A lifting body mounted on the bottom of the water and attached to the set of struts;
A set of wave breakers pivotally supported with respect to the lifting body,
By introducing buoyancy into the lifting body, the support column and the lifting body are levitated, and the wave-proof plate stands up from a state where it falls down at the bottom of the water,
Wave protection unit. The elevating body is composed of a top plate and a side wall that hangs downward from the outer edge of the top plate, and stores buoyancy by storing gas in a space surrounded by the top plate and the side wall, The wave preventing unit according to claim 1. The wave-proof unit according to claim 1 or 2, wherein a gas introduction device is installed at a water bottom position below the elevating body. The wave prevention unit according to any one of claims 1 to 3, wherein the support column is a columnar body configured to be slidable in an outer cylinder embedded in a water bottom. A levitated breakwater formed by connecting a plurality of breakwater units according to any one of claims 1 to 4.

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