Tsunami suppression device and tsunami suppression method

Abstract

To enable a cylindrical body to be easily expanded.SOLUTION: A tsunami suppression device 10 comprises: a flexible cylindrical body 20 in a contracted state; and a cylindrical body inflating portion 50 which includes a solid or liquid reactant 51 that is stored in an internal space of the cylindrical body 20 or a space communicating with the internal space of the cylindrical body 20 and that can generate gas by a chemical reaction and a reaction generating section 60 that makes the reactant 51 cause the chemical reaction and which inflates and erects the cylindrical body 20 by the gas pressure generated by the chemical reaction of the reactant 51.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] This disclosure relates to a tsunami suppression device and a tsunami suppression method.

Background Art

[0002] Patent Document 1 discloses a tsunami suppression method and device in which a pressure vessel containing a flattened and folded cylindrical body is buried in the seabed, and air is injected into the cylindrical body from an air cylinder disposed near the cylindrical body when a tsunami approaches, causing the cylindrical body to stand up. In the event of an abnormality where a tsunami is predicted, air is injected into the cylindrical body to cause it to stand up towards the sea surface. The energy of the tsunami is reduced by the bending of the thus erected cylindrical body, suppressing the damage caused by the tsunami.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above-mentioned tsunami suppression method and device, since air is injected into the pressure vessel, a pressure injection device corresponding to the number of pressure vessels is required, resulting in a complex structure and high installation costs. Therefore, there is a need to easily expand the cylindrical body.

[0005] Therefore, an object of the present disclosure is to enable the cylindrical body to be easily expanded.

Means for Solving the Problems

[0006] To solve the above problems, the tsunami suppression device comprises a flexible cylindrical body in a contracted state, a solid or liquid reactant stored in the internal space of the cylindrical body or a space communicating with the internal space of the cylindrical body and capable of generating gas by a chemical reaction, a reaction generating unit that causes the chemical reaction to occur in the reactant, and a cylindrical expansion unit that expands and uprights the cylindrical body with the pressure of the gas generated by the chemical reaction of the reactant.

[0007] Furthermore, the tsunami suppression method involves pre-positioning a contracted cylindrical body at a location where a tsunami is expected to strike, and in the event of an abnormal situation where a tsunami is expected, generating a gas through a chemical reaction of reactants, which then expands and uprights the cylindrical body. [Effects of the Invention]

[0008] This tsunami suppression device and method allows for the easy expansion of a cylindrical body. [Brief explanation of the drawing]

[0009] [Figure 1] This is a front view showing a tsunami suppression device according to an embodiment. [Figure 2] This diagram shows the positional relationship between the end of the cylindrical body, the housing, and the support member. [Figure 3] This is a cross-sectional view showing a tsunami suppression device. [Figure 4] This diagram shows the tsunami suppression device in operation. [Figure 5] This figure shows examples of combinations of the first and second reactants. [Modes for carrying out the invention]

[0010] The following describes a tsunami suppression device and a tsunami suppression method according to an embodiment of this invention.

[0011] <Tsunami suppression device> Figure 1 is a front view showing a tsunami suppression device 10 according to an embodiment. Figure 2 is a diagram showing the positional relationship between the end of the cylindrical body 20, the housing 40, and the support member 30. Figure 2 is a top view. Figure 3 is a cross-sectional view showing the tsunami suppression device. Figure 3 is a cross-sectional view taken along the line III-III in Figure 2. Figure 4 is a diagram showing the tsunami suppression device 10 in operation.

[0012] This explanation describes an example where the tsunami suppression device 10 is installed on the seabed 90. The tsunami suppression device 10 may also be installed on land. The tsunami suppression device 10 comprises a cylindrical body 20, a support member 30, a housing 40, and a cylindrical expansion section 50.

[0013] The cylindrical body 20 is formed to expand and contract depending on the amount of fluid in its internal space. Under normal circumstances, the cylindrical body 20 is in a contracted state. In the event of an abnormal situation where a tsunami 94 is predicted to strike, the cylindrical body 20 expands to suppress the tsunami 94. For example, when expanded, the cylindrical body 20 takes on a cylindrical shape, and when contracted, it takes on a flattened shape with its inner surfaces touching each other.

[0014] For example, the cylindrical body 20 may be a composite material having a tubular woven fabric and a coating. The tubular woven fabric is woven into a tubular shape by warp threads arranged in a ring and weft threads woven spirally into the warp threads. The tubular woven fabric is the part that maintains the strength of the cylindrical body 20. The coating is provided on the inner surface or both surfaces of the tubular woven fabric, and in this case it is provided on the inner surface. This coating is the part that airtightly separates the inside and outside of the cylindrical body 20. The coating is formed of, for example, flexible rubber or synthetic resin. For example, the coating may be a urethane tube or the like.

[0015] The size of the cylindrical body 20 is not particularly limited and can be set as appropriate. For example, the diameter of the cylindrical body 20 may be about 0.6m to 5m, preferably 1m to 2m. Depending on the water depth in which the cylindrical body 20 is installed, at water depths of about 10m to 50m, a diameter of 0.6m or more makes it less likely for the cylindrical body 20 to break even when wave forces act on it. Also, a diameter of 5m or less makes it easier to manufacture a cylindrical body 20 that is flexible and has sufficient pressure resistance. In this case, the contracted cylindrical body 20 is housed inside the housing 40. A diameter of 5m or less makes it easier to fold the cylindrical body 20 into a small size, and the size of the housing 40 can also be reduced.

[0016] The cylindrical body 20 maintains a deflection amount sufficient to attenuate the energy of the tsunami 94 when it acts upon it. The deflection amount of the cylindrical body 20 is inversely proportional to the bending stiffness EI of the cylindrical body 20, as shown in the equation for when a load acts on a cantilever beam. The bending stiffness EI has a positive correlation with the internal pressure and diameter of the cylindrical body 20. Therefore, by appropriately setting the values ​​of the internal pressure and diameter of the cylindrical body 20 to increase the bending stiffness EI, it is possible to obtain a cylindrical body 20 that can maintain a deflection amount sufficient to attenuate the energy of the tsunami 94.

[0017] The support member 30 supports one end 21 of the cylindrical body 20. By supporting one end 21 of the cylindrical body 20 with the support member 30, the direction in which the cylindrical body 20 expands is restricted. Here, the support member 30 is an annular pipe 30. The support member 30 may be a member other than an annular pipe 30. The annular pipe 30 covers the outer circumference of the cylindrical body 20 at one end 21 of the cylindrical body 20. The inner diameter of the annular pipe 30 may be approximately the same as the outer diameter of the cylindrical body 20. One end 21 of the cylindrical body 20 is housed inside the annular pipe 30 so that the axial direction of the cylindrical body 20 and the axial direction of the annular pipe 30 are aligned. The portion of the cylindrical body 20 on the other end 23 side of the portion supported by the annular pipe 30 extends out from the annular pipe 30. The portion of the cylindrical body 20 extending out from the annular pipe 30 is folded in a contracted state. Here, the portion of the cylindrical body 20 that is on the other end 23 side of the portion supported by the annular pipe 30 is folded in a zigzag pattern without the fabric being reversed. This zigzag folded portion 22 is placed on the annular pipe 30. The other end 23 of the cylindrical body 20 is closed by being tied or otherwise secured and overlaps the top of the zigzag folded portion 22. The portion of the cylindrical body 20 that extends from the annular pipe 30 is not limited to being placed in a zigzag pattern; for example, it may be folded flat and then wound into a coil and placed on the annular pipe 30.

[0018] One end 21 of the cylinder body 20 is blocked, for example, by being tied up. The blocking part at one end 21 of the cylinder body 20 is located inside the annular pipe 30. A part of one end 21 of the cylinder body 20 that is located inside the annular pipe 30 and is on the other end side of the blocking part is supported by the annular pipe 30. Here, the fixing member 32 supports the cylinder body 20 and the annular pipe 30 with the cylinder body 20 and the annular pipe 30 being sandwiched therebetween. The fixing member 32 includes an inner pressing member 33 that presses the inner surface of the cylinder body 20, an outer pressing member 34 that presses the outer surface of the annular pipe 30, and a connecting member 35 that connects the inner pressing member 33 and the outer pressing member 34. The cylinder body 20 and the annular pipe 30 are sandwiched in the radial direction by the inner pressing member 33 and the outer pressing member 34. For example, after the cylinder body 20 and the annular pipe 30 are sandwiched by the fixing member 32 in a state where one end 21 of the cylinder body 20 is not blocked, one end 21 of the cylinder body 20 may be blocked. The connecting member 35 may penetrate through the cylinder body 20 and the annular pipe 30.

[0019] The fixing member 32 is preferably provided at a plurality of locations along the circumferential direction of the annular pipe 30. Here, the fixing member 32 is provided at two locations separated by 180 degrees along the circumferential direction of the annular pipe 30. Here, the cylinder body 20 is alternately folded back and zigzagged along the direction connecting the two fixing members 32 (the left - right direction in FIG. 2). The two fixing members 32 are separated from each other in the axial direction of the annular pipe 30.

[0020] Also, an intervening member 36 having a curved surface is interposed between the inner pressing member 33 and the cylinder body 20. The curved surface is in contact with the inner surface of the cylinder body 20. The radius of curvature of the curved surface has a radius of curvature similar to that of the inner surface of the cylinder body 20. By providing the intervening member 36, even in a state where the cylinder body 20 is contracted, the portion of the cylinder body 20 held by the fixing member 32 can maintain an annular shape.

[0021] The housing 40 includes a main body 41 and a lid 42. The main body 41 is formed in the shape of a rectangular box with at least one side open. The annular pipe 30 and the retracted cylindrical body 20 are housed inside the main body 41. One end 21 of the annular pipe 30 and the cylindrical body 20 are supported on the bottom surface of the main body 41. The cross-section of the main body 41 perpendicular to the axial direction of the annular pipe 30 is rectangular. The length of the short side of the rectangle is approximately the same as the outer diameter of the annular pipe 30. The fixing member 32 is located on the short side. Here, the outer pressing member 34 of the fixing member 32 also presses down on the main body 41 of the housing 40. The length of the long side of the rectangle of the main body 41 is longer than the outer diameter of the annular pipe 30 and is approximately the same as half the circumference of the inner surface of the annular pipe 30. The length of the long side is approximately the same as the width dimension of the cylindrical body 20 when it is folded flat so that its inner surfaces touch each other. The zigzag section of the cylindrical body 20 has ends that extend along the longer side in the width direction and are folded back at the portion facing the shorter side.

[0022] The lid 42 covers the opening of the housing 40. The lid 42 maintains a state of covering the opening of the housing 40 in normal conditions, while being held in place so that the opening of the housing 40 can be opened when the cylindrical body 20 expands and is pressed by the expanded cylindrical body 20. For example, as shown in Figure 4, the lid 42 may include a pair of lid pieces connected to the periphery of the opening of the housing 40 via a hinge. In the example shown in Figure 4, each lid piece abuts with the other lid piece on the opposite side of the portion connected to the housing 40, creating a double-door structure. The abutting portions of the pair of lid pieces maintain a state of covering the opening of the housing 40 in normal conditions, while being held in place with a force that allows the opening of the housing 40 to be opened when the cylindrical body 20 expands and is pressed by the expanded cylindrical body 20. The pair of lid pieces may be fastened together by a fastener. In addition, for example, the lid 42 may be configured to tear when pressed by the expanded cylindrical body 20 when the cylindrical body 20 expands.

[0023] The housing 40 is fixed to the seabed 90. The manner in which the housing 40 is fixed to the seabed 90 is not particularly limited and can be set as appropriate. For example, the housing 40 may be fixed to the seabed 90 by anchors, or it may be fixed by embedding it in concrete. The lower part of the housing 40 may be buried in the seabed 90. The housing 40 does not have to be buried in the seabed 90. In this embodiment, the gas generated in the cylindrical expansion section 50 does not fill the inside of the housing 40, and the internal pressure inside the housing 40 does not increase due to the gas. Therefore, the housing 40 does not need to be a pressure vessel, and it is sufficient that it has rigidity that can withstand water pressure. When the tsunami suppression device 10 is installed on the seabed 90, seawater may fill the inside of the housing 40. However, the housing 40 may be a pressure vessel, and when the tsunami suppression device 10 is installed on the seabed 90, it may be configured so that seawater does not enter the inside of the housing 40.

[0024] The cylindrical expansion section 50 is the part that expands the contracted cylindrical body 20. The cylindrical expansion section 50 includes a reactant 51 and a reaction generation section 60. The cylindrical expansion section 50 generates a chemical reaction in the reactant 51 using the reaction generation section 60, and the gas produced by this chemical reaction expands the cylindrical body 20.

[0025] The reactant 51 is stored in the internal space of the cylindrical body 20 or in a space communicating with the internal space of the cylindrical body 20. Here, the reactant 51 is stored in the internal space of the cylindrical body 20. Here, by providing the annular pipe 30 on the outer surface of the cylindrical body 20, it is easier to secure a space for storing the reactant 51 even when the cylindrical body 20 is contracted. The reactant 51 is stored in the internal space of one end 21 of the cylindrical body 20 located inside the annular pipe 30. The reactant 51 can generate a gas through a chemical reaction. The reactant 51 is a solid or a liquid.

[0026] The chemical reaction can be any reaction that produces a gas, such as an acid-base reaction or a redox reaction. The chemical reaction may be caused by mixing multiple substances that make up the reactant 51, by heating the reactant 51, or by the flow of electricity through the reactant 51.

[0027] Here, reactant 51 is composed of multiple substances, including a first reactant 51A and a second reactant 51B. The first reactant 51A and the second reactant 51B are stored separately, and a chemical reaction occurs when the first reactant 51A and the second reactant 51B are mixed. Here, "storing the first reactant 51A and the second reactant 51B separately" means that they are stored in a way that prevents them from undergoing a chemical reaction under normal circumstances. For example, if both the first reactant 51A and the second reactant 51B are solids, and mixing the solids of the first reactant 51A and the solids of the second reactant 51B does not cause a chemical reaction, then the state in which the solids of the first reactant 51A and the solids of the second reactant 51B are mixed is also included in the state in which the first reactant 51A and the second reactant 51B are stored separately.

[0028] Here, both the first reactant 51A and the second reactant 51B are solids. This makes storage easier until the chemical reaction occurs compared to when reactant 51 is a liquid. The first reactant 51A and the second reactant 51B may be stored in separate, partitioned spaces, or they may be stored in a single, unpartitioned space.

[0029] Furthermore, if the first reactant 51A and the second reactant 51B are solids, it is preferable that both be soluble in water. This allows the first reactant 51A and the second reactant 51B to undergo a chemical reaction in an aqueous solution. In this case, as shown in Figure 4, the aqueous solution 52 after the reaction remains inside the cylindrical body 20.

[0030] Referring to Figure 5, we will now describe an example of a combination of the first reactant 51A and the second reactant 51B. Figure 5 is a diagram showing an example of a combination of the first reactant 51A and the second reactant 51B.

[0031] For example, it is possible that the first reactant 51A is a salt of a weak acid and the second reactant 51B is a stronger acid than the weak acid used in the first reactant 51A, or that the first reactant 51A is a salt of a weak base and the second reactant 51B is a stronger base than the weak base used in the first reactant 51A. This allows for a chemical reaction using an acid-base reaction. This makes it easier to initiate a chemical reaction without heating the reactant 51 or passing an electric current through it. The strength of the acid and base refers to the degree of ionization when dissolved in water. In the case of the first reactant 51A and the second reactant 51B described above, the acid in the first reactant 51A has a lower degree of ionization than the acid in the second reactant 51B.

[0032] In the case where the first reactant 51A is a salt of a weak acid, and the second reactant 51B is a stronger acid than the weak acid used in the first reactant 51A, for example, the salt of the weak acid could be a carbonate such as sodium carbonate, magnesium carbonate, or calcium carbonate, and the strong acid could be hydrochloric acid, sulfuric acid, or an organic acid. In this case, the gas produced is carbon dioxide.

[0033] For example, the salts of weak acids could be bicarbonates such as sodium bicarbonate, potassium bicarbonate, calcium bicarbonate, and magnesium bicarbonate, while the strong acids could be hydrochloric acid, sulfuric acid, and organic acids. In this case as well, the gas produced would be carbon dioxide.

[0034] For example, the salts of weak acids could be sodium sulfite or sodium thiosulfate, while the strong acids could be hydrochloric acid, sulfuric acid, nitric acid, or organic acids. In this case, the gas produced would be sulfur dioxide.

[0035] Furthermore, if the first reactant 51A is a salt of a weak base, and the second reactant 51B is a stronger base than the weak base used in the first reactant 51A, then for example, the salt of the weak base could be ammonium chloride, and the strong base could be sodium hydroxide or potassium hydroxide. In this case, the gas produced is ammonia.

[0036] The organic acids mentioned above include acetic acid, oxalic acid, citric acid, malonic acid, formic acid, propionic acid, butyric acid, lactic acid, sorbic acid, and gluconic acid.

[0037] It is preferable that the first reactant 51A is a carbonate or bicarbonate salt, the second reactant 51B is an organic acid stronger than carbonic acid, and the gas produced by the chemical reaction is carbon dioxide. If the first reactant 51A is a carbonate or bicarbonate salt and the second reactant 51B is an organic acid stronger than carbonic acid, the first reactant 51A and the second reactant 51B are easier to prepare in solid form. Also, if the gas produced by the chemical reaction is carbon dioxide, post-treatment of the tsunami suppression device 10 after use is also easier.

[0038] For example, if the first reactant 51A is sodium bicarbonate (NaHCO3) and the second reactant 51B is citric acid (C3H5O(COOH)3), the chemical reaction equation is as follows. In this chemical reaction, sodium citrate (Na3C3H5O(COOH)3), water, and carbon dioxide are produced. The carbon dioxide produced by this chemical reaction causes the cylindrical body 20 to expand. In addition, the aqueous sodium citrate solution 52 produced by this chemical reaction remains in the space where the reactant 51 was stored (in this case, the internal space of one end 21 of the cylindrical body 20).

[0039] Chemical reaction equation: 3NaHCO3+ C3H5O(COOH)3 → Na3C3H5O(COO)3+ 3CO2+ 3H2O

[0040] The reaction generation unit 60 is the part that causes a chemical reaction to occur in the reactant 51. The reaction generation unit 60 is configured according to the type of reactant 51 and the type of chemical reaction. Here, the reaction generation unit 60 is provided in such a way that the first reactant 51A and the second reactant 51B can be mixed in order to cause a chemical reaction. Specifically, the reaction generation unit 60 has a pipe 61. The pipe 61 draws water into the space where the first reactant 51A and the second reactant 51B are stored. The chemical reaction occurs when the first reactant 51A and the second reactant 51B dissolve in the water drawn in from the pipe 61.

[0041] Here, a pipe 61 is provided at the location of the fixing member 32. A pipe 61 is provided at each of the two locations of the fixing member 32. One end of each pipe 61 communicates with the internal space of the cylindrical body 20 via the fixing member 32. Fluid can be drawn directly into the internal space of the cylindrical body 20 through the pipe 61. Fluid can also be drained from the inside of the cylindrical body 20 through the pipe 61. In addition, a solenoid valve 62 is provided at the other end of one of the pipes 61. When the solenoid valve 62 opens, seawater surrounding the tsunami suppression device 10 is drawn into the internal space of the cylindrical body 20 through the pipe 61.

[0042] In this configuration, the other pipe 61 is equipped with a relief valve 63. This allows some of the gas to be released through the relief valve 63 if the internal pressure of the cylindrical body 20 exceeds a specified value due to the gas generated by the chemical reaction. This prevents the internal pressure of the cylindrical body 20 from becoming too high, and allows the expanded cylindrical body 20 to maintain a state of appropriate elasticity. In this configuration, one pipe 61 and the other pipe 61 have L-shaped piping sections that extend in opposite directions from the annular pipe 30 along the axial direction of the annular pipe 30.

[0043] When the tsunami suppression device 10 is installed on the seabed 90, the reaction generating unit 60 should be configured to be remotely controllable from land or other locations. In this configuration, the reaction generating unit 60 has a cable 64 extending from an electrical device such as a solenoid valve 62 installed on the seabed 90 to land. The electrical device such as the solenoid valve 62 can be remotely controlled from land or other locations via this cable 64.

[0044] The tsunami suppression device 10 may be positioned outside of the water. In such cases, the reaction generation unit 60 may draw water into the cylindrical body 20 using a pump. A check valve may also be provided in the piping 61 that draws water into the cylindrical body 20. This prevents backflow of water or other fluids through the piping 61.

[0045] <Methods to suppress tsunamis> Next, the tsunami suppression method of this disclosure will be described. The tsunami suppression method of this disclosure involves placing a contracted cylindrical body 20 in advance at a location where a tsunami 94 is expected to strike, and in the event of an abnormal situation where a tsunami 94 is expected to strike, generating a gas through a chemical reaction of the reactant 51, and expanding the cylindrical body 20 with the gas. This will be explained using an example of the tsunami suppression device 10 described above.

[0046] First, the retracted cylindrical body 20 is pre-positioned at a location where a tsunami 94 is predicted to strike. Here, the cylindrical body 20 is positioned by pre-installing a tsunami suppression device 10 on the seabed 90 or the like.

[0047] The tsunami suppression devices 10 are arranged in one or more rows along the coastline. When the tsunami suppression devices 10 are arranged in multiple rows along the coastline, the number of rows is arbitrary and can be set appropriately according to the area that needs to be particularly protected from the tsunami 94 (number, size, etc. of facilities that need to be particularly protected from the tsunami 94). When the tsunami suppression devices 10 are arranged in multiple rows along the coastline, the spacing between them is arbitrary, but can be, for example, about 1 to 5 times the diameter of the cylindrical body 20, or about 1 to 3 times. In addition, the tsunami suppression devices 10 are arranged in one or more rows in a direction intersecting the coastline, that is, along the direction of normal wave propagation. When the tsunami suppression devices 10 are arranged in multiple rows along a direction intersecting the coastline, the number of rows is arbitrary, but can be, for example, 3 to 20 rows, or 5 to 10 rows. When the tsunami suppression devices 10 are arranged in multiple stages along a direction intersecting the coastline, the spacing between them is arbitrary, but for example, it may be about 1 to 10 times the diameter of the cylindrical body 20, or it may be about 1 to 5 times. The water depth at the location where the tsunami suppression devices 10 are installed is also arbitrary, but for example, it may be about 10 to 50 meters.

[0048] Next, in the event of an abnormal situation where a tsunami 94 is predicted to strike, a gas is produced by a chemical reaction of the reactant 51, and the cylinder 20 is expanded by the gas. For example, if a tsunami warning is issued and a tsunami 94 is predicted to strike, the solenoid valve 62 is activated remotely from land to introduce seawater into the cylinder 20 through the piping 61. The first reactant 51A and the second reactant 51B inside the cylinder 20 dissolve in this seawater, causing a chemical reaction between the first reactant 51A and the second reactant 51B, and producing gas. For example, when solid sodium bicarbonate and citric acid dissolve in seawater, they react and produce carbon dioxide.

[0049] As the chemical reaction progresses and the amount of gas produced increases, the internal pressure of the cylinder 20 rises, causing the cylinder 20 to expand. As the cylinder 20 expands, the folded cylinder 20 unfolds, and eventually the tip of the cylinder 20 pushes open the lid 42, extends out of the housing 40, and enters the seawater. When the cylinder 20 is fully expanded, as shown in Figure 4, the tip of the cylinder 20 protrudes above the sea surface 92. At this time, the internal pressure of the cylinder 20 near the sea surface 92 may be between 0.05 MPa and 1 MPa, or between 0.1 MPa and 1 MPa.

[0050] For example, if the first reactant 51A is sodium bicarbonate and the second reactant 51B is citric acid, an acid-base reaction occurs and carbon dioxide is produced. In this case, if the diameter of the cylinder 20 is 1.5 m and the length is 15 m, the internal pressure can be set to approximately 0.25 MPa by using 235 kg of sodium bicarbonate and citric acid. In this case, the amount of seawater required to dissolve the reactant 51 is 1.5 m 3 It is approximately 0.3 m. Furthermore, at this time, the size of the sodium bicarbonate and the size of the citric acid are each 0.3 m. 3 It is to that extent.

[0051] In this state, if a tsunami 94 surges in from the left in Figure 4, the rod-shaped cylindrical body 20 is swept away by the tsunami 94 and bends significantly in the direction of the tsunami 94's propagation, as shown by the dashed line in Figure 4. The elasticity of this bending cylindrical body 20 allows it to absorb the energy of the tsunami 94. At this time, if the tsunami suppression device 10 is installed in multiple stages along the direction of the tsunami 94's propagation, the first stage cylindrical body 20, which is closest to the tsunami 94 along the direction of the tsunami 94's propagation, will bend significantly due to the tsunami 94, but this will absorb the energy of the tsunami 94 and weaken it. The weakened tsunami 94 will then cause the second stage cylindrical body 20 to bend, but the degree of bending will be less than that of the first stage cylindrical body 20. Similarly, the bending of each stage cylindrical body 20 absorbs the energy of the tsunami 94, further weakening it and reducing the force of the tsunami 94.

[0052] <Effects, etc.> With the tsunami suppression device 10 configured in this way, the cylindrical body 20 can be easily expanded because the pressure from the gas generated by the chemical reaction of the reactive substance 51 stored in the internal space of the cylindrical body 20 or in a space communicating with the internal space of the cylindrical body 20 expands the cylindrical body 20. As the expanded cylindrical body 20 flexes, the energy of the tsunami 94 is absorbed, thus reducing the force of the tsunami 94. Also, because the cylindrical body 20 is flexed by the tsunami 94, it is less likely to be destroyed by the tsunami 94, unlike breakwaters made of steel or concrete that block the tsunami 94 with their rigidity. Furthermore, the cylindrical body 20 is also expected to play a role in preventing debris and other floating materials generated inland by the arrival of a tsunami 94 from being carried out to sea.

[0053] Furthermore, the reactant 51 comprises a first reactant 51A and a second reactant 51B that undergoes a chemical reaction when mixed with the first reactant 51A. This makes it possible to easily initiate a chemical reaction that generates gas. In addition, it becomes easier to generate a large amount of gas per unit time, making it easier to fully inflate the cylindrical body 20 in the short time before the arrival of the tsunami 94.

[0054] Furthermore, either the first reactant 51A is a salt of a weak acid and the second reactant 51B is a stronger acid than the weak acid, or the first reactant 51A is a salt of a weak base and the second reactant 51B is a stronger base than the weak base. This allows for the generation of gas through an acid-base reaction.

[0055] The first reactant 51A is a salt of carbonic acid or bicarbonate, and the second reactant 51B is an organic acid stronger than carbonic acid or bicarbonate, and the gas produced by the chemical reaction is carbon dioxide. As a result, since the gas produced by the chemical reaction is carbon dioxide, disposal after use is also easy.

[0056] Furthermore, both the first reactant 51A and the second reactant 51B are solids, and the reaction generation unit 60 has a pipe 61 that draws water into the space where the first reactant 51A and the second reactant 51B are stored. The chemical reaction occurs when the first reactant 51A and the second reactant 51B dissolve in the water drawn in from the pipe 61. This makes it easy to store the first reactant 51A and the second reactant 51B. In addition, the chemical reaction can be easily initiated using water.

[0057] Furthermore, the device is further equipped with a support member 30 that supports one end 21 of the cylindrical body 20, and the portion of the cylindrical body 20 on the other end 23 side of the portion supported by the support member 30 is folded in a zigzag pattern without being inverted. Because the cylindrical body 20 is folded in a zigzag pattern, there is no need for the cylindrical body 20 to invert when it expands. In addition, the installation area of ​​the tsunami suppression device 10 can be reduced, and it becomes easier to place multiple devices in closer proximity to each other.

[0058] Furthermore, with this tsunami suppression method, the cylindrical body 20 expands due to the gas produced by the chemical reaction of the reactant 51, making it easy to expand the cylindrical body 20.

[0059] {Example} In the above example, the reactant 51 was described as being stored inside the cylindrical body 20, but this is not an essential configuration. For example, the reactant 51 may be stored inside the support member 30. In this case, it is preferable that one end 21 of the cylindrical body 20 is connected to the support member 30 so that the internal space of the cylindrical body 20 and the internal space of the support member 30 are in communication, without the end 21 of the cylindrical body 20 being closed off.

[0060] The tsunami suppression device 10 and tsunami suppression method of the present invention are also expected to be used for purposes other than tsunami suppression, such as disaster mitigation devices and methods for high tides, and as fences to prevent debris from flowing in when levees collapse due to rising river levels, thereby reducing water-related disasters.

[0061] Furthermore, the configurations described in the above embodiments and each of the modified examples can be combined as appropriate, as long as they do not contradict each other.

[0062] This specification and drawings disclose the following embodiments.

[0063] The first embodiment is a tsunami suppression device comprising: a flexible cylindrical body in a contracted state; a solid or liquid reactant stored in the internal space of the cylindrical body or in a space communicating with the internal space of the cylindrical body, which is capable of generating gas by a chemical reaction; a reaction generating unit that causes the chemical reaction to occur in the reactant; and a cylindrical expansion unit that expands and uprights the cylindrical body with the pressure of the gas generated by the chemical reaction of the reactant.

[0064] According to this tsunami suppression device, the cylinder expands due to the gas produced by the chemical reaction of reactants stored in the internal space of the cylinder or in a space communicating with the internal space of the cylinder, thus allowing the cylinder to be easily expanded.

[0065] The second aspect is a tsunami suppression device according to the first aspect, wherein the reactant comprises a first reactant and a second reactant that causes the chemical reaction when mixed with the first reactant. In this case, the chemical reaction that generates gas can be easily brought about. Furthermore, it becomes easier to generate a large amount of gas per unit time, making it easier to firmly inflate the cylindrical body in the short time before the arrival of the tsunami.

[0066] A third embodiment is a tsunami suppression device according to the second embodiment, wherein the first reactant is a salt of a weak acid and the second reactant is an acid stronger than the weak acid, or the first reactant is a salt of a weak base and the second reactant is a base stronger than the weak base. In this case, a gas can be generated by an acid-base reaction.

[0067] The fourth aspect is a tsunami suppression device according to the third aspect, wherein the first reactant is a salt of carbonic acid or bicarbonate, the second reactant is an organic acid stronger than carbonic acid or bicarbonate, and the gas produced by the chemical reaction is carbon dioxide. In this case, since the gas produced by the chemical reaction is carbon dioxide, disposal after use is also easy.

[0068] The fifth aspect is a tsunami suppression device according to any one of the second to fourth aspects, wherein both the first reactant and the second reactant are solids, and the reaction generating unit has piping for drawing water into a space where the first reactant and the second reactant are stored, and the chemical reaction occurs when the first reactant and the second reactant dissolve in the water drawn in from the piping. In this case, since both the first reactant and the second reactant are solids, storage of the first reactant and the second reactant is easy. Also, since the chemical reaction occurs when the first reactant and the second reactant dissolve in water drawn in from the piping, the chemical reaction can be easily initiated using water. For example, if the tsunami suppression device is installed on the seabed, the chemical reaction can be easily initiated using the surrounding seawater.

[0069] The sixth embodiment is a tsunami suppression device according to any one of the first to fifth embodiments, further comprising a support member that supports one end of the cylindrical body, wherein the portion of the cylindrical body on the other end side of the portion supported by the support member is folded in a zigzag pattern without being inverted. In this case, because the cylindrical body is folded in a zigzag pattern, there is no need for the cylindrical body to be inverted when it expands. In addition, the installation area of ​​the tsunami suppression device can be reduced, and it becomes easier to place multiple devices in closer proximity to each other.

[0070] The seventh aspect is a tsunami suppression method in which a contracted cylindrical body is placed in advance at a location where a tsunami is expected to strike, and when an abnormal situation occurs in which a tsunami is expected, a gas is generated by a chemical reaction of reactants, and the cylindrical body is expanded and raised by the gas.

[0071] According to this tsunami suppression method, the cylinder expands due to the gas produced by the chemical reaction of the reactants, making it easy to inflate the cylinder.

[0072] The above description is illustrative in all respects, and the invention is not limited thereto. It is understood that countless variations not illustrated can be conceivable without falling outside the scope of this invention. [Explanation of Symbols]

[0073] 10. Tsunami suppression device 20 cylinder 21 One end 22. Folding section 23 Other end 30 Support member 32 Fixing member 40 cabinets 41 Main unit 42 Lid 50 Cylindrical expansion part 51 Reactants 51A First reactant 51B Second reactant 60 Reaction generation section 61 Piping 62 Solenoid valve 64 Cables 90 Undersea 92 sea level 94 Tsunami

Claims

1. A flexible cylindrical body in a contracted state, The cylinder includes a solid or liquid reactant stored in the internal space of the cylinder or a space communicating with the internal space of the cylinder, capable of generating gas through a chemical reaction, and a reaction generating unit having a pipe for drawing water into the space where the reactant is stored, and drawing water from the pipe into the space where the reactant is stored to cause the chemical reaction in the reactant, and a cylinder expansion unit that expands and stands up the cylinder with the pressure of the gas generated by the chemical reaction of the reactant, A tsunami suppression device equipped with the necessary components.

2. A tsunami suppression device according to claim 1, The tsunami suppression device comprises a first reactant and a second reactant that undergoes the chemical reaction when mixed with the first reactant by water drawn in from the piping.

3. A tsunami suppression device according to claim 2, The first reactant is a salt of a weak acid, and the second reactant is an acid stronger than the weak acid. Or, A tsunami suppression device in which the first reactant is a salt of a weak base, and the second reactant is a base stronger than the weak base.

4. A tsunami suppression device according to claim 3, A tsunami suppression device in which the first reactant is a salt of carbonic acid or bicarbonate, the second reactant is an organic acid stronger than carbonic acid or bicarbonate, and the gas produced by the chemical reaction is carbon dioxide.

5. A tsunami suppression device according to any one of claims 2 to 4, Both the first reactant and the second reactant are solids. A tsunami suppression device in which the chemical reaction occurs when the first reactant and the second reactant dissolve in water drawn in from the piping.

6. A tsunami suppression device according to any one of claims 1 to 5, The system further comprises a support member that supports one end of the cylindrical body, A tsunami suppression device in which the portion of the cylindrical body on the other end side of the portion supported by the support member is folded in a zigzag pattern without being inverted.

7. A method for suppressing a tsunami using a tsunami suppression device according to any one of Claims 1 to 6, The contracted cylindrical body is pre-positioned at a location where a tsunami is predicted to strike, In the event of an abnormal situation in which a tsunami is predicted, water is drawn in from the pipe and the chemical reaction of the reactant is caused to produce the gas. A method for suppressing tsunamis, comprising inflating and uprighting the cylindrical body with the aforementioned gas.

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