JP2006257842A - Tidal wave sluice - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tidal wave sluice enabling the saving of cost and time, less constrained with respect to site location, securely functioning, not providing risk to an operator, and suppressing adverse effect on river flows, lives, industrial activities, landscape, and growing environment for living organism. <P>SOLUTION: A river floor near the mouth of a river is formed smooth to use it as a foundation for a tidal wave sluice. A bed is installed on the surface of water at such a level that can secure a necessary flow amount in the direction that crosses the water flow of the river. A lower layer tidal wave flow cut-off board is mounted on the bed in the direction that crosses the flow of the river. An upper layer tidal wave flow cut-off board having a floating body is swingably mounted on the bed. The tidal wave sluice comprises a lower layer tidal wave flow cut-off board drive mechanism and an upper layer tidal wave flow cut-off board raised attitude holding mechanism holding the raised attitude of the upper layer tidal wave flow cut-off board when raised. Water cut-off boards having swing support parts installed on the upstream side of the foundation placed on the river floor and swing support parts combined with the swing support parts are arranged parallel with each other in a direction crossing the flow of the river. The tidal wave sluice comprises a water cut-off board raised attitude holding mechanism stabilizing the water cut-off boards when the water cut-off boards are raised and a water cut-off board connection mechanism loosely connecting the adjacent water cut-off boards to each other. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a tsunami sluice provided near a point where a river or water channel is poured into the sea. In addition to the tsunami, storm surges can be considered as the cause of abnormal high water levels on the sluice sea side, but from the standpoint of disaster prevention, it is generally considered that the high water level during a tsunami exceeds the high water level during a storm surge. Therefore, the tsunami sluice also serves as a storm sluice to prevent the high water level from entering due to the storm surge. In the following text, the term “river etc.” is used for rivers and waterways, and “estuary etc.” is used for the vicinity of points where rivers and waterways pour into the sea. Also, when referring to both tsunamis and storm surges, the term “tsunami etc.” is used. Further, here, upstream and downstream terms are used according to the river flow, and the downstream side of the water stop plate is the sea side of the water stop plate.

  Many of the tsunamis are thought to be caused by seabed gaps and volcanic activity caused by earthquakes. In coastal areas where earthquakes and volcanic activities are active, there is often a history of severe damage caused by tsunamis. The Japanese archipelago, which is only about 1% of the earth as seen from the whole of the earth, and its surroundings have experienced earthquakes that account for 10% of the earth. The Japanese archipelago is located in a high-density area where earthquakes occur, and the population and social assets are now concentrated at a very high density in the plains along the coast. Currently, Japan is the only country that is said to be a so-called industrially advanced country with a high population density that is located in an area where earthquakes occur frequently.

If a massive earthquake of magnitude 8 class near the Japanese archipelago causes a tsunami, the land will be hit by a massive and disastrous disaster that humankind has never experienced before. The area around the Japanese archipelago is considered to be an active period of seismic activity in the future. Considering the life and property lost in the event of a disaster, and the cost and time required for post-disaster reconstruction, prevent tsunami damage. Therefore, it is necessary to take effective measures immediately.

  There are many embankments on the coast today to prevent damage from high waves and storm surges. This type of embankment is not originally intended to prevent tsunami disasters, but it is effective against ordinary high waves and storm surges, and has some effects on small-scale tsunamis. However, conventional levees cannot prevent flood damage in the case of large-scale tsunamis. Therefore, as a disaster prevention measure for large-scale tsunamis, tsunamis on the coastal land of Sanriku Coast and Kochi Prefecture and in the coastal waters. There is a construction example where a breakwater was constructed.

Although there are not many examples of construction, the storm surge sluice, which is intended to prevent the high water level from entering due to storm surges, can be closed to the estuary to prevent storm surges and tsunamis. Tsunami sluice gates have been established at the mouth of the Mitarai River in Susaki City, Kochi Prefecture. However, these storm surge sluice gates and tsunami sluice gates are designed to withstand the impacts of tsunamis by making them large, heavy and solid, so they are mainly heavy, hard materials such as concrete, rocks, earth and sand, and metals. It must be constructed in large quantities, requires a large amount of money and a long period of time for construction, and has a large impact on life, industrial activities, landscapes, and the environment for living organisms during and after construction. It was. In addition, it was often difficult to construct these large-mass sluices on the soft ground near the estuary so that they could function without being affected by the earthquake motion that caused the tsunami.

  The tsunami has a very high speed in the deep water area, while the wave height is small, and as the coastal water depth is small, the wave height decreases and the wave height increases, as if flowing from the sea offshore to the land. After rushing and landing on the shore, it climbs while increasing the flooded area, eventually losing power, but depending on the factors that hinder the flow, the distance of the tsunami climbing changes greatly. Frictional resistance to flow increases due to the influence of buildings, roads, etc., as well as revetments, wave-dissipating blocks, and tsunami breakwaters, while the tsunami's uphill distance is shortened, while river beds such as inflowing rivers have low frictional resistance to flow From there, the tsunami goes up to the far upstream. Usually, rivers and other dikes are not designed to cope with the high water level caused by tsunami dredging, even though they can cope with the increase in water from the upstream, so the tsunami that has risen overflows the river dike. There have been reports of cases where unexpected areas were damaged by flooding. In addition, when the updraft is going to flow in the opposite direction and return to the sea, the destructive power of the water flow increases because it is a water flow involving a large amount of sediment, rocks, and other drifting objects, This is one factor that expands the flood damage caused by the tsunami. When considering tsunami disaster prevention, it is important that the high water level of the tsunami that reaches the vicinity of the estuary does not enter the river, but a tsunami sluice is installed at the estuary to completely prevent it.

  The tsunami has a very long wavelength, so the high water level lasts for a long time during an attack and is susceptible to inundation, and when the wave approaches the shore, it has a high destructive power by acting like a flow. The tsunami is repeatedly attacked by waves several times or more, and large-scale tsunamis are characterized by extremely high wave heights, which are high enough to protect an area from high water level entry caused by tsunamis. It must be surrounded by the tsunami breakwater and tsunami sluice without interruption. As mentioned above, the location near the point where rivers and waterways flow into the sea is the most important point in considering tsunami disaster prevention, but the cost and time involved in construction, as well as various geological and technical problems. Therefore, except for a few examples where conditions are allowed, it can be said that the present situation is that an effective method for blocking a high water level caused by a tsunami or storm surge by setting up a tsunami sluice was not found.

  On the other hand, although it is different from the tsunami sluice, in recent years, as an overflow prevention structure in the levee body, a groove or a hole is provided in the upper end of the existing levee, and a hose member is accommodated in it and covered with a lid. It has been proposed to increase the height of a river dike by introducing water into a hose that protrudes out of a groove or hole. Also, as a tide gate for rivers and the like, a steel door body standing up with an air bag has been proposed, but it cannot prevent the high water level of the tsunami that reaches in a short time after the occurrence, and the tsunami sluice gate It cannot be adopted as a substitute for.

To completely prevent tsunami disasters, tsunami sluice gates should be constructed in all estuaries where human activities are conducted, but due to cost and time constraints, the areas protected from disasters by tsunami sluices are limited. The reality is that Precisely predicting the tsunami attack, which is a natural phenomenon, is extremely difficult for humans today, so it is not always possible to be prepared for a tsunami disaster, but it is possible to accurately predict the limited cost and tsunami attack. In situations where it is not possible, constructing a tsunami sluice in as many estuaries as possible along the coast saves construction costs and time when trying to protect more lives and property from the tsunami. Less tsunami sluice gates and construction methods are required. In addition, in construction, it is desired to have a construction that has little influence on life, industrial activities, landscapes and living environments of living things.

1996 Patent Application No. 341453 Japanese Patent Application No. 2001-116494 Masahiko Oya et al. “Knowing and Preventing Natural Disasters” Kokon Shoin 1996 Kashiwagi Kyo et al. “New edition Coastal Engineering” Kyoritsu Publishing Co., Ltd. 1996

  The problem to be solved is to provide a tsunami sluice that can save construction costs and time and has few location restrictions. Even if the power supply is cut off due to an earthquake preceding the tsunami, it can be done quickly and reliably. The objective is to provide a tsunami sluice that can be deployed and has excellent disaster prevention effects that do not pose a danger to the operator. In addition, the tsunami that can suppress adverse effects on living and industrial activities, landscapes and living environments in construction, and that allows the tsunami flow stoppage plate to self-recover after tsunami convergence without hindering normal river flow To provide a sluice.

  In the case of a tsunami sluice that forms an embankment with standing water-stop plates in the event of a rise in the water level, the river bed at the point where the sluice is to be installed is formed smoothly to form the foundation of the tsunami sluice. Above the water surface at the water level that can secure the required flow rate for rivers and waterways, a base with a swing support part consisting of two parallel horizontal axes is installed in the direction across the river flow, In one row of the rocking support parts, the lower tsunami flow water blocking plate with the rocking fulcrum provided in the vicinity of the upper side is placed so that the lower side is in contact with the foundation with the lower layer tsunami flow water blocking plate in the lowest position. Mounted in the direction that crosses the river flow, swings near the bottom end with the upper-layer tsunami-stopping water plate with the buoyant body attached to the rest of the two rows of swing support sections on the base A support part is provided, and this is attached so that it can swing freely. The upper and lower tsunami dams are placed in the opposite directions in the vicinity of the oscillating support part of the tsunami dam, and the upper tsunami Equipped with a lower tsunami dammed water plate drive mechanism that is connected to power the rocking sway of the dammed water plate, the upper tsunami dammed water plate standing posture that maintains the standing posture of the upper tsunami dammed water plate when standing up A tsunami sluice with a holding mechanism, which can be stored by folding the tsunami-stop plate on a river during normal times.

In addition, the lower tsunami flow stop plate driving mechanism of the tsunami sluice gate of the present invention is connected to the vicinity of the swing support portion of the lower tsunami flow stop plate and the vicinity of the swing support portion of the upper tsunami flow stop plate. , A combination of arm and link, a combination of cam and cam follower, or a combination of gears, crossing the water flow on the foundation where the lower side is in contact with the oscillating lower tsunami dam plate in the lowest position A tsunami sluice with a step in the direction that crosses the water flow on the upstream or downstream side of the river on the foundation of the tsunami sluice that is formed on the riverbed at the point where the sluice is to be provided. The upper layer tsunami breakwater plate standing posture maintaining mechanism is a chain or rope that connects the fulcrum provided on the upper side of the upper layer tsunami breakwater plate and the fulcrum provided at a point slightly downstream of the tsunami breakwater plate on the foundation. Or an upper-layer tsunami flow-stop plate pedestal having a contact surface provided on the upper upstream side of the upper-layer tsunami flow-stop plate, and a gap formed between the water-stop plates between the side edges of adjacent water-stop plates The buoyancy body attached to the upper tsunami flow-stop plate accommodates the gas stored in the air chamber provided in the upper tsunami flow-stop plate or the upper tsunami flow-stop plate. A tsunami sluice gate made of foam.

  In the tsunami sluice of the present invention, the upper tsunami levitation plate rises due to the rising tsunami water level that hits from the shore of the sluice, and the lower tsunami levitation plate that is powered by the levitation of the upper tsunami flow The water flow near the bottom of the tsunami that tries to enter the tsunami sluice below the tsunami sluice is blocked, and the upper tsunami waterstop rises further due to the rising tsunami level. An upper-layer tsunami flow-stop plate can also be deployed above the tsunami sluice to prevent the intrusion of the high-water level portion of the tsunami water flow that attempts to lift up the high part without river flow during normal times.

As described above, the tsunami sluice of the present invention is such that the dam body autonomously develops without requiring external power or human operation, and the tsunami flow stop plate does not become an obstacle to normal river flow during normal times. It is a tsunami sluice that folds over a river and stores it. It is made lightweight so that the upper tsunami flow stop plate can be quickly raised when the tip of the tsunami flow is caught, and the lower tsunami flow stop plate can also be quickly swung back. Since each waterstop can be produced efficiently at the factory, less work is required at the construction site, and the cost and time for construction of the tsunami sluice can be saved significantly.

  In addition, the tsunami sluice gate of the present invention is stored on a base placed on the riverbed near the point where rivers and waterways pour into the sea during normal times, so there is no hindrance to the river flow that is problematic by providing a tsunami sluice . In addition, the water gates and the water blocking plates are small in mass, and can be used with structurally appropriate water blocking plates that can avoid concentrated loads structurally. Soft ground that tends to be universally encountered when constructing structures near the estuary that can be sealed by extending the edges of the edges, making it more tolerant to ground displacement and being damaged by earthquakes prior to the tsunami. There is an advantage that the problem caused by can be reduced.

  Since the tsunami sluice gate of the present invention can be stored on a foundation provided with most of the waterstop plate on a river bed during normal times, adverse effects on living, industrial activities, landscapes and living environments of living organisms can be suppressed. The tsunami sluice gate of the present invention is a buoyancy generated by placing the buoyancy body attached to the upper tsunami flow-stopping plate underwater, so the structure becomes very simple and the maintenance and maintenance work of the tsunami sluice gate It is also possible to reduce the cost required for. In addition, when the high water level of the tsunami is eliminated, the lower tsunami flow-stopping plate is lifted by the weight of the upper-layer tsunami flow-stopping plate and stored under the basement, so that the river flow is not hindered.

  The best mode for carrying out the present invention will be described with reference to the drawings. FIG. 1 is a transverse cross-sectional view of the central portion of the present tsunami sluice 1 placed near the mouth of the tsunami when a tsunami-stopping plate is deployed, with the sea side 2 on the left and the upstream side 3 of the river on the right. The figure shows a tsunami sluice in the form of a levee body by standing up and down waterstops in the event of an abnormality accompanied by a rise in the water level. The river bed 4 near the estuary is smoothly molded to form the foundation 5 of the tsunami sluice. A base 8 having a swing support portion 7 composed of two parallel horizontal axes is provided above the water surface 6 at the time of water level, which can secure a necessary flow rate as a river or water channel on the foundation, in a direction crossing the water flow 9 of the river. In one row of the two rows of swing support portions provided in the base, the lower tsunami flow stop plate 11 having the swing fulcrum 10 provided in the vicinity of the upper side is in a state where the lower tsunami flow stop plate is at the lowest position. The lower part 12 is attached in a direction crossing the river flow so as to contact the foundation. Further, the swing support portion 16 is provided near the lower end 15 in the state where the upper-layer tsunami waterstop plate 14 to which the buoyancy body 13 is attached is placed on the rest of the two rows of swing support portions provided in the base. The swinging direction of the upper and lower tsunami flow-stop plates and the lower tsunami flow-stop plates are located in the vicinity of the swing support portions of the lower-layer and upper-layer tsunami flow-stop plates, respectively. The lower tsunami flow-stop plate driving mechanism 17 is connected so that the swing of the upper-layer tsunami flow-stop plate becomes the power of the swing of the lower-layer tsunami flow-stop plate. An upper-layer tsunami flow-stopping plate standing posture holding mechanism 18 that holds the standing posture of the flow-stopping plate is provided. During normal times, the upper tsunami flow-stop plate is lowered by its own weight, and the lower tsunami flow-stop plate is swung and stored by the connected lower tsunami flow-stop plate drive mechanism. It is.

In FIG. 1 and FIG. 2, the lower tsunami flow-stop plate driving mechanism is a chain 19 that is connected so that the swing of the upper tsunami flow-stop plate becomes the power of the swing of the lower tsunami flow-stop plate. May be a tough rope 20, a combination 21 of arms and links shown in FIG. 3, a combination 22 of cams and cam followers shown in FIG. 4, or a combination 23 of gears shown in FIG. In addition, if a step 24 in the direction crossing the water flow is provided on the foundation where the lower side is in contact with the oscillating lower tsunami flow stoppage plate at the lowest position, the water pressure of the tsunami is received. Therefore, it is possible to stabilize the lower tsunami flow stop plate pushed to the upstream side of the river, and to effectively block the tsunami water flow that leaks from the lower tsunami flow stop plate to the upstream side of the river. 3 is a cross-sectional view of the central part of the tsunami sluice of the present invention during the high water level caused by storm surge, and FIGS. 4 and 5 are cross-sectional views of the central part of the tsunami sluice of the present invention during the high water level caused by the tsunami. is there.

In addition, as shown in FIG. 5, a lower tsunami flow-stop plate is provided by providing a concave portion 25 in a direction crossing the water flow on the upstream or downstream side of the river at the foundation of the tsunami sluice and periodically removing drift sand accumulated in the concave portion. It is possible to avoid the tsunami sluice dysfunction caused by sand drift that tends to accumulate in the vicinity. In FIG. 5, the upper layer tsunami breakwater plate standing posture holding mechanism is provided with a fulcrum 26 provided near the upper side of the upper layer tsunami breakwater plate and a fulcrum 27 provided at a slightly separated point on the sea side of the upper layer tsunami breakwater plate. As shown in FIG. 3, a shock absorber 29 is provided in the middle of the wire rope 28 that connects the two, and as shown in FIG. It becomes a tsunami-stopping water plate standing posture holding mechanism.

FIG. 6 is a bird's-eye view of an embodiment of the tsunami sluice according to the present invention. When the tsunami sluice of the present invention is provided in a river or the like, it is necessary to adjust the dimensions and number of each water stop plate to a suitable one depending on the width of the river, the state of the embankment, the situation where the tsunami sluice is placed, etc. When there are multiple water stop plates, the gap between the water stop plates is extended by misaligning the side edges of adjacent water stop plates. Sealing with the packing 31 can almost completely block the tsunami water flow that leaks to the upstream side of the river. In addition, when the buoyancy body attached to the upper tsunami flow-stop plate is a gas such as air stored in the air chamber provided inside the upper tsunami flow-stop plate or a foam to be accommodated inside the upper tsunami flow-stop plate, The buoyancy body is protected by the outer skin 32 of the tsunami waterstop. The base of the tsunami sluice includes a method of providing a pier-like base on the riverbed and a method of supporting the girder-like base 33 by passing it over a river. In the explanation, the upper-layer tsunami flow-stop plate is located on the sea side, and the lower-layer tsunami flow-stop plate is located on the upstream side. If it is connected so as to be the driving force of the lower tsunami flow-stopping plate, there is no problem as a tsunami sluice.

The tsunami sluice shown in FIG. 6 is attacked by a tsunami or other high water level 34 from the left side of the figure, but the upper tsunami stagnation plate that has generated buoyancy due to the high water level caused by the tsunami or the like rises, thereby preventing the lower tsunami The water flow near the bottom of the tsunami that tries to enter the tsunami sluice below the tsunami sluice flows in the direction opposite to the river flow and blocks the water flow near the bottom of the tsunami. However, it has risen further and deployed an upper tsunami sluice plate above the tsunami sluice to prevent the intrusion of the high water level part of the tsunami water stream that tries to lift the high part without river flow during normal times.

  The tsunami sluice of the present invention is effective not only for tsunami but also for storm surge. By providing the tsunami sluice of the present invention near the estuary and providing an effective tsunami breakwater 35 in addition to the vicinity of the estuary, inundation damage caused by an abnormally high water level such as a tsunami can be prevented.

It is a center part cross-sectional view at the time of the tsunami water stop board expansion | deployment of this invention tsunami sluice. It is a central part cross-sectional view of this invention tsunami sluice folded over the river flow. It is a cross-sectional view of the center part in the high water level caused by the storm surge of the tsunami sluice gate of the present invention in which the lower tsunami flow stoppage plate driving mechanism is a combination of an arm and a link. FIG. 3 is a cross-sectional view of the center part in a high water level caused by a tsunami of the tsunami sluice gate according to the present invention in which a lower tsunami flow stop plate driving mechanism is a combination of a cam and a cam follower. It is a center part cross-sectional view in the high water level which the tsunami of this invention tsunami sluice which made the lower tsunami flow-stop board drive mechanism the combination of gears brings about. It is a bird's-eye view of one Example of this invention tsunami sluice at the time of tsunami attack. Example 1

Explanation of symbols

1 Tsunami sluice gate of the present invention 2 Sea side of tsunami sluice 3 Upstream side of river 4 River bed 5 Foundation of tsunami sluice 6 Water surface at the water level that can secure the required flow rate for rivers and waterways 7 Swing support consisting of two horizontal axes Part 8 Base 9 Arrow indicating direction of river flow 10 Oscillating support part of lower tsunami flow stop plate 11 Lower tsunami flow stop plate 12 Lower part with lower tsunami flow stop plate in the lowest position 13 Buoyant body 14 Upper-layer tsunami flow-stop plate 15 Near the lower end of the upper-layer tsunami flow-stop plate 16 Swing support portion 17 Lower-layer tsunami flow-stop plate drive mechanism 18 Upper-layer tsunami flow-stop plate standing posture holding mechanism 19 Chain 20 Leash 21 Combination of arm and link 22 Combination of cam and cam follower 23 Combination of gear 24 Step difference 25 in the direction crossing the water flow 25 Concave portion 26 in the direction crossing the water flow 27 A fulcrum 27 provided near the upper side of the upper tsunami waterstop Somewhat separated Supporting point 28 Wire rope 29 Shock absorber 30 Upper tsunami breakwater plate base 31 Packing 32 Upper tsunami breakwater plate skin 33 Girder base 34 High water level due to tsunami 35 Effective tsunami breakwater

Claims (13)

  In the case of a tsunami sluice that forms an embankment with an ups and downs water stop plate in the event of an abnormality accompanied by a rise in the water level, the river bed at the point where the sluice is to be installed is smoothly molded to form the foundation of the tsunami sluice, A base with a swing support part consisting of two parallel horizontal axes is installed above the water surface at the water level to ensure the required flow rate for rivers and waterways in the direction crossing the river flow, and two rows provided for the base In one row of the swing support parts, the lower tsunami flow stop plate with the swing fulcrum provided near the upper side is placed so that the lower side is in contact with the foundation with the lower tsunami flow stop plate in the lowest position. Attached in the direction crossing the river flow, the upper tsunami flow-stopping plate with the buoyant body attached to the rest of the two rows of rocking supports provided on the base rocks near the lower end. The lower support tsunami flow and the upper tsunami flow The upper and lower tsunami flow stop plates swing in opposite directions near the swing support section of the water plate, and the upper tsunami flow stop plate swings in the lower tsunami flow stop water. Equipped with a lower tsunami flow-stop plate driving mechanism that is connected so as to drive the rocking of the plate, and an upper-layer tsunami flow-stop plate standing posture holding mechanism that holds the standing posture of the upper tsunami flow-stop plate when standing up Tsunami sluice gate provided.   The lower tsunami flow-stop plate driving mechanism comprises a chain or a rope connecting the vicinity of the swing support portion of the lower tsunami flow stop plate and the vicinity of the swing support portion of the upper tsunami flow stop plate. The tsunami sluice according to 1.   The lower tsunami flow stop plate driving mechanism comprises a combination of an arm and a link connecting the vicinity of the swing support portion of the lower tsunami flow stop plate and the vicinity of the swing support portion of the upper tsunami flow stop plate. The tsunami sluice according to Item 1.   The lower tsunami flow stop plate driving mechanism comprises a combination of a cam and a cam follower provided in the vicinity of the swing support portion of the lower tsunami flow stop plate and in the vicinity of the swing support portion of the upper tsunami flow stop plate. The tsunami sluice according to 1.   2. The lower tsunami flow-stop plate driving mechanism comprises a combination of gears provided near the swing support portion of the lower tsunami flow stop plate and the swing support portion of the upper tsunami flow stop plate. Tsunami sluice. The tsunami sluice according to any one of claims 1 to 5, wherein a step in a direction crossing the water flow is provided on a foundation with a lower side in contact with the oscillating lower tsunami flow stoppage plate at the lowest position. The tsunami sluice according to any one of claims 1 to 6, further comprising a recess in a direction crossing the water flow on the upstream side of the river on the foundation of the tsunami sluice to be formed on the riverbed at the point where the sluice is to be provided. The tsunami sluice according to any one of claims 1 to 7, further comprising a recess in a direction crossing the water flow on the downstream side of the river on the foundation of the tsunami sluice that is formed on the riverbed of the point where the sluice is to be provided. The upper layer tsunami breakwater plate standing posture maintaining mechanism is a chain or rope that connects the fulcrum provided on the upper side of the upper layer tsunami breakwater plate and the fulcrum provided at a point slightly downstream of the tsunami breakwater plate on the foundation. The tsunami sluice according to claims 1 to 8, wherein: The tsunami according to any one of claims 1 to 9, wherein the upper-layer tsunami-flow-stop plate standing posture maintaining mechanism is an upper-layer tsunami-flow-stop plate pedestal having a contact surface provided on the upper upstream side of the upper-layer tsunami flow-stop plate. Sluice. The tsunami sluice according to any one of claims 1 to 10, wherein a gap generated between the water blocking plates is sealed by extending side edges of adjacent water blocking plates and extending.   The tsunami sluice according to any one of claims 1 to 11, wherein the buoyancy body attached to the upper-layer tsunami flow-stop plate is a gas stored in an air chamber provided inside the upper-layer tsunami flow-stop plate. The tsunami sluice according to any one of claims 1 to 11, wherein the buoyancy body attached to the upper-layer tsunami flow-stopping plate is a foam accommodated inside the upper-layer tsunami flow-stop plate.