A tsunami evacuation shelter that is integrated with a dike and serves as a multipurpose structure

Abstract

The construction of tsunami shelters has not progressed. In the event of a huge tsunami in the Nankai Trough, it is predicted that there will be 320,000 deaths and 1 million victims in the dead of winter and in the middle of the night. It is speculated that 10 years after the Cabinet Office announcement, the construction of crematoriums has been progressing. In some areas, a 10-meter tsunami is said to strike in 5 minutes, leaving no room for evacuation. The challenge is how to save as many lives as possible during the daily lives of local residents without interruption for 24 hours. 【Means of Solution】 There are levees in the area, and it is as if a shelter is right in front of you in daily life, allowing families to evacuate quickly. You can feel at ease 24 hours a day. If you are prepared, there is no danger. How wonderful it is to be able to live safely and securely every day.

Description

Technical Field

[0001] The present invention relates to a tsunami evacuation shelter that, in a coastal area where a tsunami strikes suddenly, avoids the direct impact of the tsunami wave force by integrating with the back of an existing dike, can maintain the internal survival air volume even when underwater, and enables quick evacuation due to its proximity to houses.

Background Art

[0002] It is predicted that 320,000 people will die in the tsunami associated with the expected Nankai Trough megathrust earthquake. Ten years have passed since the prediction was announced by the Cabinet Office in 2011, and it is awaited how many people have been saved. Just constructing a 10 m high flood dike alone will result in a long coastline extension and the national finances will collapse. Also, the sea cannot be seen, and there is strong opposition from the residents. However, it is not the case that nothing needs to be done. Transferring to high ground requires a huge amount of cost and labor. A tsunami tower also requires a huge amount of cost. Given that a 10 m high tsunami will strike in 5 minutes, slogans like "can't escape in time" and evacuation drills on TV to gather residents and escape to high places are completely off the mark. If existing dikes are utilized, evacuation of residents near the coast will be quicker and more people will be saved. When searched on the patent information platform, there was 1 case for "flood dike shelter" and 9 cases for "dike shelter". Among them, 4 cases were relevant. Patent Document 1 is about building a new high dike that does not allow overtopping with earth filling, and simply providing a shelter inside the dike in a cave structure, and the earth embankment will collapse in case of inundation. Patent Documents 2 and 3 are also new constructions, with scale and cost being too excessive, and there is a possibility that the space is large and it may float due to buoyancy. Being in sections like a three-building structure does not have the original function of the dike. Patent Document 4 is even larger in scale, forming apartments, schools, hotels, etc. inside the dike, and the cost is also enormous and can be said to be out of the question. This application is different in that it utilizes existing low-height dikes throughout the country, integrates a shelter behind them, is inexpensive in terms of cost, and can save many dike coastal residents by making use of the long dike extension.

Prior Art Documents

Patent Documents

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-225996 [Patent Document 2] Japanese Patent Application Laid-Open No. 2024-040608 [Patent Document 3] Japanese Patent Application No. 2016-164344 [Patent Document 4] Japanese Patent Application Laid-Open No. 04-309611

[0004] [Non-Patent Document 1] Article by Nakagawa Kogyosho [Summary of the Invention] [Problems to be Solved by the Invention]

[0005] The problem and proposition are to save 320,000 dead and 1 million victims predicted by tsunami disasters. The 320,000 people live along the coast where tsunamis strike. Therefore, it is the most natural idea and the most effective to utilize the dikes deployed along the coastlines across the country built by our predecessors. Dikes are located along the sea and are naturally in the areas where tsunamis strike the coast. This means they are in the tsunami-affected areas, and most of the victims live there and are most affected. They are located by the sea, close and familiar to the residents. They surround the coastal areas and have a long extension. They are heavy and sturdy against wave forces. However, they are only lacking in height. It is too hasty to discard them as useless just because they lack height. It is only the height exceeding the dike height that is insufficient. However, it is quite impossible to build a 10m-high high-tide dike. Therefore, it was considered to compensate for this lack of height with functions. That is, if a tsunami shelter that can maintain air and survive even when submerged and the dike are integrated into a combined structure, the weaknesses of the dike can be compensated for, and the dike, which was regarded as a useless long object ineffective against high tsunamis, can be revived, and there is hope of saving 320,000 people.

[0006] The tsunami is predicted to cause 320,000 deaths according to the Cabinet Office's announcement. We are waiting for the release of the results on how many lives have been saved through the measures taken in the past decade. I don't think it's a repeat of the Fukushima Daiichi Nuclear Power Plant accident by Tokyo Electric Power Company, but isn't it relying on gods or incantations, saying that the tsunami won't come, won't be revealed, or simply can't come until it actually does? The then-president of Tokyo Electric Power Company was found guilty in court for neglecting countermeasures despite being able to foresee the tsunami. For the embankment managers, even to avoid being reported and becoming defendants, if a 10-meter tsunami is predicted, it is necessary to raise the embankment by more than 10 meters. However, it doesn't seem to be progressing. If it is predicted but not implemented, based on the guilty verdict of the president of Tokyo Electric Power Company, it is easy to assume that the national and local government leaders, who are the embankment managers, will also be found guilty. I'm tired of hearing the usual excuse of "unexpected." The residents are still at risk of their lives. Doesn't it resemble the situation in the Gaza Strip where the lives of the residents are treated lightly by Israel, leaving the lives exposed to death? In addition to raising the embankment, tsunami countermeasures also include tsunami towers and evacuation to high ground. Especially for tsunami towers, how many out of the 320,000 people can reach it during the dead of winter, in the middle of the night, while they are sound asleep, when the maximum damage is predicted? The cost-effectiveness is extremely low, almost zero. Although the maximum damage is predicted to occur in the dead of winter and at night, the countermeasures do not assume the worst-case scenario. It is also a measure that abandons the elderly, pregnant women, and wheelchair users who cannot reach it in the dead of winter and at night, and it can be said that it lacks fairness significantly in terms of the budget using taxpayers' money. The entrance to the tower is locked with a fence to prevent non-believers. Even if there are costs for resident and on-duty managers and an elevator, the emergency power supply, statutory inspection fees, and renewal fees are not sufficient. If it is a 35-meter-high tsunami tower, it's different, but anything lower won't be helpful. To deal with unexpected increases, the additional construction cost of the tower will also double. If the height is insufficient due to repeated reviews of predictions each time, it will become a dangerous and rather useless building. It's truly a waste of taxpayers' money. There is no guarantee of life regardless of the height. It's just that if one dies, it was an unexpected height. Moreover, the townscape will be easily washed away and destroyed. At least, the residents should not be put at risk of their lives. This won't lead to the strengthening of the country. We must learn from past cases, especially the Great East Japan Earthquake. For the evacuation to high ground, not the whole town is evacuated, but only the town hall is moved. Can we abandon the vitality of the town and the residents?The figure of the father desperately searching for his junior high school daughter who went missing in the previous Noto flood disaster was unbearably sad. She was accidentally discovered by a fishing boat at sea 10 days later, which brought relief, but I realized how tragic it is for a family to be torn apart. If only the ward office staff were saved while many of the family members and ordinary residents went missing, a tragedy would be waiting to happen. For most of the remaining 16 hours of a day outside working hours, I am on flat ground. What am I protecting? Even if there are important documents, there is no need for a warehouse with digitalization. Even for the household register, the residents are no longer in this world. There is no limit to the number of searchers, the cost, or the period. Evacuation to high ground needs to be reconsidered, or if evacuation is carried out, it should be done first for the residents who pay taxes, and measures to save the lives of the residents on the lower flat ground should also be taken in parallel.

[0007] It is understandable that the cost of constructing high sea dikes would be prohibitively high for widespread application across the country. Therefore, it is worth considering whether we can make use of the existing dikes installed along the coastlines throughout the country by our predecessors. Dikes have long-term continuity along the coastline, are robust with the hardness of concrete, and are excellent in terms of durability. They are heavy and do not float, and naturally have sufficient resistance to wave forces. However, their greatest weakness is that they are not tall enough to withstand the height of a large tsunami. Since tsunamis flow over the dikes, without additional measures, the entire town would be engulfed by overtopping or dike breaches. Clearly, low dikes cannot save the lives of town residents. In particular, in areas like the narrow inlets of Rikuzentakata City, the scene was one of complete devastation. Therefore, it is thought that if people can at least maintain air even when submerged by a tsunami, they can survive. Compared to the 2011 Tohoku earthquake and tsunami, for the huge Nankai Trough tsunami with a higher wave height, a recurrence of six waves in six hours is predicted, and the inundation time is limited, quickly followed by the ebb tide, during which air is supplied. Dikes have sufficient weight and stiffness; they just lack height. On the other hand, shelters that can hold air are useful for people's survival. First, by combining with the resistance of shelters that support them integrally behind the weight and stiffness of the dikes, the impact of large wave forces can be avoided as a whole. It is possible to consider shelters integrated with long dike extensions. There is a great advantage in that people can quickly take refuge in the nearest shelters in the living area, and low dikes, weak dikes vulnerable to overtopping, and old dikes can be reinforced against dike breaches. Even if a dike breaches at a single point, no matter how excellent its weight and stiffness, it marks the end. People do not want to leave their town, and it can accommodate the number of people who wish to stay. The current dikes are familiar in daily life, and evacuation is quick. Moreover, they are inexpensive, can be applied in any region across the country, and if the desired region is named, it is relatively easy to obtain a budget for national resilience, saving many people and allowing them to live in peace without worry. How wonderful that would be. In particular, the lives of the young and future elementary school students must not be taken. The news of Okawa Elementary School in the 2011 Tohoku earthquake and tsunami spread around the world in an instant. The teachers also suffered in the trial. This pain must not be repeated. Even if the townscape is sacrificed temporarily, as long as there are lives, life can be restored. The more people who survive, the more we can expect the revival of a new town. For example, it is also possible, in the opposite sense, to intensify the land and replace it with high and sturdy buildings. Be reborn as a town resilient to disasters.The lives of people and the safety of local communities can be ensured. Dike managers will also be relieved and become proactive if they can contribute to saving many lives even with weak and low dikes. The excuse of the usual phrase "unexpected" will never be tolerated. How noble it is to be useful and contribute to people. It is no exaggeration to say that it provides the optimal solution for strengthening the country's land.

[0008] Therefore, it can be said that realizing a tsunami shelter that can save many lives, is close at hand, inexpensive, and where people are mostly at home late at night when the greatest damage occurs, and can ensure people's seamless 24-hour life including the safety of residents and the safety of the local community, will contribute to solving the problem. Tsunamis can strike at any time, anywhere, and at any time of day. In areas where it is difficult to evacuate from tsunamis, the concept of "evacuating in time" has been proposed, but it goes without saying that those who can evacuate in time will be saved, and most people cannot evacuate in time. We must not be deceived. In particular, disaster evacuation vulnerable groups such as the elderly, pregnant women, and wheelchair users cannot evacuate in time. It is too harsh for the government to shift the responsibility onto the individuals by saying they should have known. On the other hand, looking at daily life, cars are especially indispensable for work, shopping, and going to the hospital, especially in rural areas. If only one could escape far away by car, but if traffic concentrates on the main roads, one will be caught in traffic jams. Although tsunamis can strike at any time, the tsunami associated with the expected Nankai Trough megathrust earthquake is predicted by the Cabinet Office to have a maximum wave height of 34.4 m, resulting in 320,000 deaths and 1 million casualties. Along the coast, a 10-m high tsunami is expected to strike within 2 to 5 minutes, and the greatest damage will occur in the dead of winter, in the middle of the night. Ten years have passed since the announcement. How many people have been saved? In recent years, footage of the great tsunami during the Great Kanto Earthquake was discovered. The problem remains unsolved because all that is seen are warnings, and no sign of those truly responsible for saving countless lives. People are just engaged in endless discussions, deliberations, and research, feeling self-satisfied as if they are doing their jobs. Finding results is the job. In the world, this is called the Odawara Council. Still, evacuation shelters should be able to accommodate 320,000 people. It is necessary to verify and announce whether there are enough places even at this late stage. The progress of acquiring land for crematoriums and their construction also needs to be announced. Cremation cannot be carried out without a certificate of identity. Administrative procedures such as DNA testing, dental matching, and fingerprint matching take 1 to 3 years, and the construction of freezer warehouses to prevent decomposition is also urgently needed. In such emergencies and during major disasters, the government should actively promote the effectiveness of the My Number card with a photo for identity verification. I would like to believe that the government does not intend to neglect this forever. Are they lacking in wisdom? If they had dealt with it earlier, people could have lived more peacefully every day. The responsibility for neglecting it for 10 years is not light. However, since there is no one taking responsibility, who can be blamed?The tsunami in the previous Great East Japan Earthquake struck as early as 15 minutes after the earthquake, and most struck after one hour, so it can be said that there was enough time for evacuation. However, in the case of tsunamis caused by the Nankai Trough Earthquake or the Japan Sea Earthquake, the wave rise is so steep that this is not the case at all. In the case of a sudden strike like the tsunami off Oku-Shiretoko Island, there is not even enough time to evacuate outside or any margin for preparation. We should have learned from actual tsunamis. Six waves repeated over a six-hour period. Since we don't know when it will strike within a day, we must be prepared for 24 hours. However, although this unexpected and cruel tsunami always follows the natural order and rule of occurring after the shaking of an earthquake, there is a sense of justice in giving advance warnings through the ebb tide, rumbling sounds, etc. We must find a way out and answer this. The meaning of a tsunami strike five minutes later means that if the shaking stops two or three minutes after the earthquake, conversely, there may or may not be two or three minutes for evacuation. Spending time and budget on accurate earthquake analysis and being satisfied with oneself in this work, if the evacuation warning system is announced three minutes after the earthquake at the earliest, it is often already too late. This should be understandable even to elementary school students. We should know that it is of no use to the residents on the verge of life and death in coastal areas. Following the example of the loud sirens or announcements in the case of the largest earthquakes, or the missile warning sirens in Israel and Palestine a few seconds later, it should be automatically transmitted immediately. The damage caused by tsunamis is far greater than that of missile attacks. The person responsible for creating the accurate system can be said to be responsible for accuracy but not for whether it helps save lives. Regarding the tsunami warning due to the previous Tonga volcanic eruption, most people replied that they did not evacuate. Despite the capsizing of a ship in Kochi. If there is no immediate loud siren, one will be extremely anxious. One must always be prepared to make self-judgment and self-defense based on the magnitude of the earthquake shaking. If one dies, there will be no regrets, but at least one must decide what one would do to avoid regrets. After all, it seems that the crisis avoidance switch does not turn on until the rumbling sound, ground noise, and high waves are right in front of us. In the cold winter, resignation comes before thinking stops. There is no time to change into pajamas when taking a bath or going to bed. Just getting a dawdling child to put on shoes takes five minutes right away. There is no time to hesitate and think.One must rush out with an emergency backpack. It's certain that many people, whether they're being honest or not, are giving up. Of course, one must get rid of the bias that one will somehow be okay on one's own. Instant unconditional reflex and repetitive action training are necessary. Housing conditions also have an impact. In ordinary houses, there's nothing, not even a shred. In a sturdy apartment building, it might be thought that one would be saved if on a high floor, but there's no guarantee that the tsunami height will be below the expected height. People tend to think they'll be saved by vertical evacuation or rooftop evacuation, but looking at the results, buildings lower than the tsunami height and their rooftops will be completely engulfed by the tsunami. How terrifying and merciless was the approaching tsunami. There was a lawsuit regarding the death of someone who took rooftop evacuation at a local bank up ahead. What is the country thinking? What about the evacuation plan of "Just escape somehow"? Considering that one is at home for half of the 24 hours and evacuation is not easy in areas without tall and sturdy buildings nearby. Still, one must anticipate danger 24 hours a day, including during the dead of winter and the middle of the night, whether at home, at work, at school, etc. Anyway, installing evacuation shelters near the residents is a step towards solving the problem, including bringing peace of mind. On the other hand, for those who can't wait for a tsunami that might strike tomorrow and for those who want to take self-help measures, it's also possible to quickly install individual or household shelters on their own, which can help with instant evacuation. If one's life can be saved with a budget of 200,000 yen to 1 million yen per person, it can be considered worth considering. Rather, one can't take money to the grave. It's a once-in-a-lifetime decision to use the money while alive. Also, for shelters in areas where the ground is even slightly higher, for example, where the ground elevation is about 1 or 2 meters, the possibility of survival increases because the fresh air exchange is faster.

[0009] The tsunami shelter integrated with the dike is very close and immediate for the residents in the coastal area. If the entrance to the dedicated shelter where the residents themselves jump in is pre-assigned by the residents themselves, rapid evacuation is possible. Don't forget the family members left in care. Among the people in the town hall who return from the high ground during the day, even those who work 8 hours are not at home, and the dangerous time zone of the remaining 16 hours after returning home occupies a large part. It can be said that the number of safe and reassuring hours throughout the 24 hours in the shelter increases, and the effective value of the fair result and possibility of protecting lives rises. Thus, be prepared for rapid evacuation as a family so that an earthquake or tsunami can strike at any time during the 24 hours. It is important that the family does not get separated. If they drift apart and get separated, the search cost will be several times higher. It should be recognized that not only is it an individual problem of simply being in distress, but if people are in distress, huge national costs will be incurred. It is possible to conduct 24-hour thinking training centered on the family against tsunamis that can strike at any time and anywhere, and against the bias of thinking that only oneself will be okay. Preparedness for emergencies is useful only when there is thinking and training on a daily basis. There should be no break against tsunamis that can strike at any time and anywhere. The issue of being able to respond without interruption for 24 hours at any time and anywhere can be solved. If individuals and families are to be saved, imagination and the ability to envision are required. We have valuable examples in the Tohoku region. It is easy to assume that leaving it to others will result in the same outcome. Even if one has received excellent education, one must not lose one's life randomly. What have you thought about and done, or tried to do, in the past 10 years? Isn't the evacuation method and actions putting you in danger instead? Ultimately, how many young lives with a future can you save? A strict self-evaluation is required.

[0010] The tsunami in the Nankai Trough repeats six waves over a six-hour period along the coastal area. Considering the six repeating waves as one wave per hour, and since the tide recedes for half of the time, fresh air automatically replenishes and replaces when the water level at the ebb tide is lower than the height of the shelter entrance. Thus, there is an idea that one only needs to endure the inundation for 30 minutes, which is half of the time. This can be a hint for crisis avoidance. That is, the regional characteristic value of 0.5 m3 per person per hour can be used. For children and the elderly with lower vital capacity, it is also possible to arbitrarily interpret it as half of that, i.e., 0.25 m3 per person per hour. A person cannot survive without air in water, which can be considered almost instant death. Thinking in this way, it can be considered that having a shelter is better than not having one at all, and realistic values of 0.5 m3, 0.3 m3, and 0.25 m3 with a smaller volume can also be adopted for those exceeding the fixed capacity. Since the tsunami can occur at any time, equipment according to the season and measures against the cold in winter are necessary. In this way, the issue of enabling corresponding measures according to each region, each person, and each season can be solved. The entrance is provided at the lower part, so the internal drainage is fast, there is less moisture and condensation in normal times, and the issues of maintenance management and corrosion prevention, which are problematic for structures, can be solved. If there is enough space inside, preparing things like rubber boats and air mats inside can solve the problem that vulnerable evacuees such as the elderly will not get wet even if there is inundation. Especially in winter, there is concern about hypothermia, and air mats and blankets are also very helpful to prevent direct contact with cold water. Consider the optimal response for each season. By enabling evacuation according to the life scenarios and the number of people, the issues in a wider area can be solved. At the fish market near the sea, which is the nearest workplace, they tidy up. It is the nearest evacuation in front of one's eyes, and safety can be ensured almost in daily life. It is close, fast, and above all, simple. It is important to save the lives of as many as 320,000 people.

Means for Solving the Problem

[0011] To solve such problems, the tsunami evacuation shelter integrated with and also serving as a working structure of the levee of the present invention provides a tsunami evacuation shelter integrally on the back of an existing levee. Using the heavy levee as a shield and being located at the back can avoid the direct impact wave force of a tsunami, and it is assumed that the shelter can be prevented from tipping over due to the tipping moment acting on the shelter. It is also assumed that the shelter can be extended in the extension direction by utilizing the long extension of the levee. When a tsunami approaches, the water surface is covered at the height of the entrance and exit. Even if it is submerged by the tsunami, it has an airtight upper-closed hollow structure with the necessary air volume to survive underwater, and it is a non-hermetic structure with the entrance and exit provided on the land side. In this way, since the body wall surface does not receive a large bending moment, the wall thickness can be relatively thin, and yet it is assumed that the weight of the concrete body does not exceed the buoyancy acting on the body when submerged and does not float. End walls are provided at both arbitrary ends in the length direction to form a hollow box shape, and it is characterized in that the levee and the shelter overlapping due to the tsunami wave force also serve to reinforce the levee and prevent levee breaches.

[0012] In addition, for the tsunami evacuation shelter integrated with and also serving as a working structure of the levee of the present invention, the vicinity inside the shelter at the entrance and exit of the open structure is surrounded in a U-shape in plan view by a pool wall slightly higher than the height of the entrance and exit, or extended to the end walls at both ends for surrounding. This can mitigate the intrusion of floating debris and temporarily form a storage area for tsunami water, thus contributing as a damper to mitigate the direct impact wave of the tsunami. For a large tsunami, by covering the water surface at the height of the pool wall of the storage area, the air from the floor height of the shelter is not released as internal air, that is, by making it compressed air, the internal retained survival air volume can be increased compared to the open structure without such enclosures.

[0013] Furthermore, the tsunami evacuation shelter integrated with and also serving as a working structure of the levee of the present invention is characterized in that the top of the levee is provided for use as a road for levee management or for the passage of general vehicles and bicycles.

[0014] In addition, the tsunami shelter of the combined structure integrated with the levee of the present invention is designed to respond to a tsunami height that is at least slightly higher than the existing levee top height with a height limit, and a small levee can be installed above the levee top within the range of the moment of resistance to overturning of the tsunami shelter behind, or the existing levee top can be incorporated and raised, or the shelter can be extended to the backland to increase the resistance to overturning, and it is characterized in that a higher small levee can be installed.

[0015] In addition, the tsunami shelter of the combined structure integrated with the levee of the present invention extends the shelter in the direction of the houses to facilitate faster evacuation, and is characterized in that it expands or extends in the direction perpendicular to the levee. Levees have various names such as seawalls, breakwaters, high-tide levees, storm surge levees, and revetments. Here, these are collectively referred to as levees. The tsunami shelter can also serve as an evacuation shelter for floods, high tides, typhoons, strong winds, tornadoes, and missile blast countermeasures in addition to tsunamis.

Advantages of the Invention

[0016] By using the existing levees, it is not necessary to incur huge costs for conventional tsunami countermeasures such as highland evacuation, high storm surge levees, and tsunami towers. As a result, the lives of many coastal residents who are worried about direct tsunamis and sudden attacks can be saved. Moreover, people can be saved from tsunamis whose arrival time is unknown within 24 hours. It is a miracle from the brink of despair. How fortunate that families will not be separated. It can be said that existing low and old levees are strengthened at once by integrating them with the tsunami shelter. While expressing gratitude for the hard work of our predecessors in building levees along the long coastline, we will make effective use of them. We will bring them back to life. Levee managers can also feel at ease by promoting this. Furthermore, if the levee managers use the tsunami shelter as a combined structure with the levee, they can promote the project as part of strengthening the country's resilience. If they can contribute to saving the lives of many residents, it will be fulfilling and motivating. They will not be questioned about their management responsibilities and will not end up unfortunately as defendants. The tsunami evacuation shelters behind the dikes are particularly effective, especially in the coastal areas of narrow inlets where tsunamis strike like demons in an instant, and even more effective in densely populated areas and areas with little yard space. They can also be applied to the dike sections and gabion revetment sections where the height of the river section where the tsunami surges upstream at the same time is insufficient, as long as the ground problems can be solved. The entrances and exits of the evacuation shelters on the dikes can be said to be assigned seats for each resident, a gift from heaven, and one can jump in immediately. If there are countermeasures and people can be saved, cooperation will also be integrated and disaster prevention in advance can be achieved. Although the total predicted damage is said to be 170 trillion yen, it is not known how much of that is accounted for by human lives. Anyway, human lives are precious. First of all, disaster prevention in advance for human lives should be considered. There is hope of saving the lives of the 320,000 people who had given up or rather been left unattended, and the light of hope for saving 1 million victims can be seen. The person himself has no idea that he is counted among them. He understands it vaguely but doesn't think he will die. When the light of hope of being saved can be seen, people become positive. All kinds of wisdom will come out. If year-round, 24-hour seamless evacuation becomes possible, people can train themselves on their own. Evacuation responses can be made instantaneously. With such efforts, people can live peaceful daily lives. How wonderful that is. Community solidarity can be expected. If the burden during disasters further increases due to this huge and seemingly endless tsunami countermeasure in the budget for the reconstruction of Tohoku, Japan's sinking is clearly visible. Then, if crematoriums for 320,000 people are built and land is secured, the economic effect will be great. Failing to respond to what has been predicted to cause damage for 10 years will truly expose Japan to shame in the world. It is clearly obvious what will become the target of criticism. Who is the responsible person? It has not been determined other than the dike managers, and due to the lack of self-awareness, it has been progressing slowly. It is self-inflicted, and these efforts of self-help, mutual help, and public assistance that will never progress no matter how long one waits. First of all, a determination to protect one's own life by oneself is necessary. The movement positions of family members who go to school and work are assumed daily, and the family can act together, strengthening the sense of unity and bond so that the family does not fall apart. The nearby tsunami evacuation shelters on the dikes can be said to be safe zones where one can jump in immediately and assigned seats that provide mental support. The national budget should be used for such things. It is obvious to anyone's eyes that if one prepares today for a possible tsunami tomorrow, one will be safe from tomorrow. It will become a property of society. One can be grateful for the precious time of being alive now. No one will say that this is being wasted.If lives can be saved, life insurance companies won't go bankrupt either. A tsunami that could strike at any time, perhaps tomorrow. If the state funds the construction of shelters, it might save 320,000 lives. The predicted number of deaths during winter, at midnight when people are at home, is 320,000. It is thought that people would die instantly or by drowning as their houses are washed away all at once. However, in the present invention, even if the house is washed away, the lives that have fled to the levee won't be washed away. It is extremely cheap compared to the value of human life. Japan has spent 10 years just going through the motions of training for TV appearances, being good at self-satisfaction and making excuses, and is withering away without doing anything, only to be laughed at by the whole world. Let's make a flower bloom here. If the shelter is made of precast concrete products, it can be manufactured in a factory, has good quality, and is suitable for direct transportation. The construction period is also short. Hurry up.

Brief Description of the Drawings

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Mode for Carrying Out the Invention

[0018] Common reference numerals are used throughout the drawings and the detailed description to indicate the same elements.

[0019] Many residents live in the coastal area along the dike. Furthermore, in the narrow inlet area, many houses are densely located near the coastline. In the inlet, the tsunami becomes amplified in height, and with the increased momentum of the tsunami, houses are completely engulfed, presenting a total destruction scenario. The sight of being swallowed up and tossed around by the waves can be easily imagined. Urgent measures must be taken. Since the shelter is supported behind the dike, the stiffness, weight, and long extension of the existing dike can be utilized. By integrating with the existing dike, the bearing capacity is also improved, and the tsunami evacuation shelter can be said to be a combined structure with the dike that has a mutually beneficial effect, as many lives in the coastal area can be saved. There are two types of shelters. Type A is for evacuation vulnerable groups such as wheelchair users, the elderly, and pregnant women without a wall at the entrance. Type B has a standing wall and a pool wall approximately 80 cm higher than the entrance height at the back of the entrance to prevent the intrusion of floating objects, expand the evacuation space and the amount of air retained in water, and is for healthy people because they need to climb over it. It is better to attach a handle if possible.

[0020] Figure 1 shows an image cross-section of the general wave force under the condition of existing dikes throughout the country being subjected to high waves. Figure 2 is a diagram imaging the situation of the wave force when a tsunami of about 10 m hits. The wave force is said to be three times the hydrostatic pressure. It is affected by intense overtopping. Figure 3 is a general diagram imaging the situation where a tsunami shelter is provided in accordance with the slope of the back of the dike and resists the wave force of a large tsunami as an integral part of the seaward side wall and the trapezoidal box-shaped structure. Figure 4 is a diagram showing a parallelogram with a gradient in accordance with the slope of the dike, and Figure 5 shows an example of a box culvert made of a rectangular precast product. The space between the back of the dike is filled with concrete to make it integral. In order to reduce the influence of overtopping, the height of the top edge of all tsunami shelters is basically the same as or lower than the top edge height of the existing dike. Considering the joint intervals and breaks of the existing dike in the longitudinal direction of the dike, partitions are provided at regular intervals to divide the hollow rooms. The extension of the shelter is about 10 m as one block, and in some cases, an intermediate wall may be provided for reinforcement. A hollow shelter that holds air will float if it is too light. First, to prevent the tsunami shelter from floating, the weight of the hollow concrete body is made greater than the buoyancy acting on the body. Figure 6 is a schematic diagram for simplicity of calculation in the form of a rectangle to obtain the required wall thickness as reinforced concrete with a specific gravity of 2.5. The entrance and exit are provided at the lower part of the landward side wall or the end wall. The structure is a non-sealed structure that is not a sealed structure. Since the air pressure and water pressure inside and outside the shelter are equal according to Pascal's principle, no bending moment is applied to the wall, and the structural wall thickness is not so necessary. Extremely, it can be said that a single sheet of paper is sufficient for the wall. However, a wall thickness is required for the box-shaped structure that supports and supplements the strong wave force related to the dike behind the dike. Resistance to salt damage and wall thickness are also necessary. Appropriate rigidity and resistance as a structure against torsion and deformation are also required. The box-shaped shelter extended to the back and rear has a resistance moment against overtopping and overturning that can be said to be inherently provided by the box shape characteristics. A trial calculation example of the wall thickness, which is rectangular for simplicity, is shown below. The body weight needs to be greater than the buoyancy. As a rough estimate, assuming a dike height of 2m, the same height of 2m, width of 3m, extension of 1m, entrance height of 0.7m, pool wall height of 0.8m, wall thickness of 0.3m, and specific gravity of reinforced concrete of 2.5, weight = (2 * 3 - 0.7 * 2.7 - 0.7 * 2.4) * 2.5 = 6.075 tons > buoyancy = 2 * 3 - 0.7 * 2.7 = 4.11 tons. If the wall thickness is as thin as 0.2m for a precast product, weight = (2 * 3 - 0.7 * 2.8 - 0.8 * 2.6) * 2.5 = 4.9 tons > buoyancy = 2 * 3 - 0.7 * 2.8 = 4.04 tons, so it will not float, but it can be said that there is little margin in weight due to the thinness. In Type B with a pool wall, the weight of the pool wall is added. With a wall thickness of 0.3m, it increases by 0.3 * 0.8 * 2.5 = 0.6 tons. With a wall thickness of 0.2m, it increases by 4 tons. Assuming the distance to the entrance is 1m, the buoyancy = 2 * 3 - 0.8 * 1 = 5.2 tons. So, with a wall thickness of 0.3m, weight = 6.075 + 0.6 = 6.675 > 5.2, and with a wall thickness of 0.2m for a precast product, weight = 4.9 + 0.4 = 5.3 > 5.2. Therefore, when using a precast product, the wall thickness should be 0.25m or more. However, if calculated per 10m extension, the remaining land-side wall part of the entrance is 7m, the end wall is from 2 * 3 * 0.2m to 0.3m, and there are also intermediate walls and corner reinforcement haunches, so it is okay in terms of calculation, but a margin is desired.

[0021] The utilization of natural laws is also helpful. According to Archimedes' principle, air, which has a lower specific gravity than water, rises in water. The rising air is concentrated in the upwardly convex space. The buoyancy, according to Archimedes' principle, is equivalent to the buoyancy of the volume of water displaced by the object in the shelter. Although it is a hollow shelter containing air and is light, the weight of the structure needs to exceed the buoyancy. Furthermore, when a 10m tsunami comes, according to Boyle's law, the internal volume is compressed to 1 / 2, so the buoyancy is halved simultaneously. According to Pascal's principle, the pressure inside and outside the shelter is equal. Thus, there is no pressure difference between the inside and outside like a sealed structure on the entire perimeter wall of the shelter with an entrance at the lower part of the side wall. A wall as thin as a sheet of paper is sufficient. According to Boyle's law, a horizontal water surface formed near the height and lower part of the entrance of the shelter forms a sealed space. Since the tsunami height is 10m and the water pressure is 2 atmospheres, the air inside the shelter is compressed to 1 / 2 upwards, to 1 / 3 at 20m, and to 1 / 4 at 30m, and accordingly the water level and water surface also rise, so don't panic. Since the inside is an enclosed space, the water level inside is interlocked with the outside water level of 10m relative to the internal water level of 0.5m, so the rising speed is slow at a speed of 1 / 20, and the air will surely remain at the upper ceiling part. The air intake should naturally be upwards, and the compressed and rising air accumulated near the ceiling of the top plate is sucked in. The buoyancy is equivalent to the volume of the shelter air in water, so as the water level in the shelter rises, the buoyancy also gradually rises. However, when the water level rises above the height of the entrance of the shelter, the internal air is compressed and the volume decreases, so the buoyancy decreases. When setting the capacity of the shelter, for the elderly, children with low vital capacity, the elderly can be considered to have half the oxygen consumption, so it can cover the excess of the capacity and can also be considered as a margin. Regarding the water pressure burden caused by the maximum tsunami of 34m height, there is news of a rescue 62 hours after the bottom of a shipwreck at a water depth of 30m off the coast of Nigeria in 2013. After the first wave ends, the water level drops, so fresh air is exchanged. With a design of 1m3 / hour, there is no need to worry so much. First of all, it is a prerequisite to build the shelter without hesitation. If one hesitates and doesn't take action forever, being a naked person with nothing to withstand the incoming tsunami will result in being submerged, and without air for even a moment, people will die. That is nothing but a waste of time like the Odawara Council, just deliberating and researching, without achieving the goal of saving people's lives. The time lost in the past 10 years will not come back. There is no hope for the next 10 years either.There is no person responsible who needs to produce results. However, I would like to think that if we move forward bravely, we can regain productive time in the next 10 years.

[0022] No matter how high the tsunami height is, 6 waves will repeat within a maximum of 6 hours. Therefore, wave troughs will form and natural air exchange can be expected. As a result, the designed air volume can also be in units of the tsunami period, one hour. If there is a primary school nearby, it is also considered to extend the tsunami evacuation shelter closer. Although it is extreme, in the case of extreme cold, in order to prevent sudden death from hypothermia, a connecting passage is installed as a wind trunk covered like an airplane tarp. By devising like this, there is hope for the presented figure of 1 million people whose sacrifices are predicted, and for each inorganic mass of individual lives. Although subject to transportation dimension limitations, if precast concrete made in a factory is used, higher quality and shorter construction periods can be expected. The application of a rectangular box culvert is considered. Concrete is placed between the slope of the levee and the culvert to integrate them. In addition, for the case when there is insufficient air and it becomes difficult to breathe, it is advisable to place floating rings with a 10m rope. They can float up to breathe and are useful for the return after the ebb tide. The anchor of the rope should be installed inside the wall of the shelter, and the floating rings should be installed outside the shelter. Ensure that the total air volume equivalent to the volume of the floating rings is not lost. However, it is necessary to devise a way to coil the rope so that only the floating rings do not float up.

Example

[0023] The levee is robust against the wave force and lateral force of high waves. Therefore, the seaward side wall of the box-shaped shelter is basically integrated with and in close contact with the back of the levee. It can bear part of the reaction force of the wave force and can also be said to have an interaction effect of hiding from the direct impact of the wave force. On the other hand, the levee is vulnerable to overtopping that exceeds the top edge. Therefore, the top edge of the shelter is basically set below the top edge height of the levee to avoid the influence of overtopping. The structure of the shelter is made of concrete and has a non-closed hollow structure to ensure a living air volume of 1 m3 per person. The height of the entrance and exit is about 0.7 m, and the width can be 2 m to 5 m. It is provided at the lower part of the landward side wall and end wall. Both ends of the shelter are surrounded by vertical standing walls and end walls to enclose the space. The concrete structure has a weight that overcomes buoyancy so that it does not float even when underwater. That is, the wall thickness of the concrete structure requires 30 cm or more for ordinary reinforced concrete. For precast products, 25 cm or more is desirable. Assuming that the end walls are provided at 10 m intervals, the internal air volume is for 0.7 * 2.4 * 10 = 16.8 people according to Type A in Figure 7. It is advisable to provide a gradient and slope towards the back inside the entrance and exit. Handrails are required for Type A, which is for vulnerable evacuees such as the elderly, pregnant women, and wheelchair users whose evacuation is not fast. Therefore, by lowering the bottom plate by about 0.3 m, an entrance and exit height of 0.7 m from the ground can be ensured. The gap between the back of the levee and the newly constructed tsunami shelter can be filled with concrete mortar or integrated, or methods such as using joint materials and thin materials such as waterproof sheets, fiber sheets, veneer boards, and elastomers to mitigate the influence of new and old concrete can also be considered. However, since there are differences in the expansion and contraction amounts due to temperature changes and differences in drying shrinkage over the years between the newly constructed and existing old levees, it is necessary to appropriately intervene with joint materials to prevent cracking in order not to interfere with each other. Since there are joints in the existing levee at regular intervals, it is necessary to consider, for example, adjusting the interval of the end walls of the new concrete shelter so as not to be affected by it. The height of the shelter is about 0.7 m so that people do not concentrate at the entrance and exit at the same time, but considering that two people and two-wheel vehicles may jump in at the same time, a width of 2 m to 5 m is appropriate.

Example

[0024] The B type in Figure 8 is for healthy people and requires climbing over the wall. Providing a gathering area and a pool at the entrance and exit of the shelter can serve as a damper to relieve the wave force of the tsunami and can also maintain a large amount of air necessary for survival. The B type can accommodate 0.6 * 2.4 + 0.8 * 1.4 = 25.2 people. Figures 9 and 10 show a plan view where the pool wall and the retaining wall are U-shaped, or the retaining walls at both ends and the walls up to the end walls in Figure 11. Attention should be paid as the latter has a smaller air volume compared to the former. The height should be about 10 cm higher than the height of the entrance and exit. It is advisable to install handrails on the upper part of the entrance and exit walls and the pool walls. If benches are prepared indoors, people can spend time comfortably.

Example

[0025] By making the lower part of the retaining walls of the intermediate wall and the stop wall in the shelter into passage holes for communication and through passage with the adjacent room, a large number of shelters can be continuously installed like a row of houses in the long direction. As an example of the arrangement in Figure 9, if the continuous arrangement is A, A, B, B, a passage hole can be provided at the lower part of B so that even if one is flooded up to the ceiling due to damage or the like, people can escape into the adjacent room. As an example of the arrangement in Figure 10, if the alternating arrangement is A, B, A, B, the evacuees should decide in advance which shelter to escape into. However, attention should be paid as opening a hole between the adjacent A and B may cause the loss of the air volume in B. If all residents decide in advance through pre-training which one to escape into, the evacuation will be straight and fast. However, as shown in Figure 11, if the pool wall of the B type is extended to the boundary wall and a through hole with the height of the pool wall or the entrance and exit height is provided at the lower part of the boundary wall, continuous passage between A and B and through passage along the entire length of the continuous shelter will be possible.

Example

[0026] Use the top edge of the shelter as a management road, a traffic lane for general vehicles, or a bicycle lane. Refer to Figure 12.

Example

[0027] If it were possible to raise the top height of the existing levee a little higher, for example, to level L1, with respect to the tsunami height, many houses and residents could be saved. In that case, consider installing a small levee at the top of the shelter within the range of the resistance and strength against the overturning of the shelter. Furthermore, if it were possible to raise the elevation including the top of the existing levee in cooperation with the levee, the height of the small levee could be further increased overall. Also, if the tsunami evacuation shelter could be extended to the back area, it would be stronger against overturning and the small levee could be made higher. Refer to Figures 13, 14, and 15.

Example

[0028] The combined force of the levee and the shelter is expected to provide more resistance against the tsunami wave force. Even so, people who are slightly away from the shelter may be confused about whether to escape to the evacuation agreement building, the mountains, or the high ground. Therefore, extend the shelter in the direction of the town, that is, perpendicular to the levee. It can be said to reach out. In particular, if it is extended in the direction of the elementary school, the entrance and exit will be very close, and the evacuation will be rapid. We must not take the life of a future elementary school student. Protecting them is the greatest responsibility of adults. In areas with a declining population, cooperation from residents such as providing vacant land can also be expected. Refer to Figure 15.

Example

[0029] Although it is a hollow shelter, if cracks occur, air will escape into the water. Air leakage is fatal. The causes include the aging dry shrinkage of concrete, the deformation, cracking of the structure due to the huge earthquake before the tsunami, and further cracks due to the aging difference from the existing dike, the joint position, and the mutual interference due to surface contact. Therefore, it is necessary to take countermeasures. So, placing plastic bags such as convex plastic bags and airtight sheet bags along the inner wall upside down provides double safety in case of emergency and prevents air leakage. Personally, even garbage bags can be useful. The basic required air volume is 1.0 m3 / person·hour. However, for children and the elderly, considering their lower vital capacity and half of the characteristic value, it will be added in case of overcrowding. Lifebuoys, a framework for preventing the intrusion of water-permeable floating debris, small air cylinders, small oxygen cylinders, protective plates from floating debris, flashlights, smartphones, radios, chemical heaters, bread, water, simple toilets, blankets, warm clothes, disaster prevention rucksacks containing garbage bags, waterproof sheets, scoops for removing mud deposited outside, and furthermore, a lifebuoy with a rope about 10 m long is also very helpful when it becomes difficult to breathe. It can float and return to its original position with the ebb tide. Placing a water-permeable snake cage near the entrance and exit can prevent the intrusion of floating debris and can be used as a seat when pulled inside. The bench can be used as a bench. It can easily withstand about 6 hours of evacuation. In addition, wooden rafts are also available. Lifebuoys are better placed outside the shelter, and their anchor fixation is inside the shelter. It can't be helped even for about 10 people. It is advisable to equip the land side wall with protective devices for mitigating the impact of floating debris and cushioning devices such as tires. To prevent getting wet from the internal flooding of the tsunami, it is advisable to deploy wooden floors, rubber boats, vinyl floating floors, air mats, and boards inside. It is also advisable to consider providing for emergencies through through-holes from adjacent rooms. Anyway, regular enlightenment, education, and training are necessary for tsunami countermeasures.

Explanation of symbols

[0030] 1 Dike 2 Tsunami evacuation shelter 3 Wall of the shelter 4 Internal air space of the shelter 5 Entrance and exit 6 Top edge of the dike 7 Back and inclined slope of the existing dike 8 High wave force 9 Ground 10 Sea surface 11 Tsunami wave power 12 Overflow tsunami wave power 13 Inverted trapezoidal box shelter 14 Parallelogram box shelter 15 Rectangular shelter, culvert box shelter 16 Filled concrete 17 Pool wall 18 Wheelchair 19 Handrail 20 Permeable floating debris intrusion prevention fence 21 Bench 22 Floating ring 23 Handle, anchor 24 Rope 25 Horizontal water surface formed by the entrance / exit height during tsunami entry 26 Horizontal water surface formed by the pool wall height during tsunami entry 27 Shelter floor surface that maintains air until inundation up to the pool wall height 28 Vehicle 29 Bicycle 30 Guardrail 31 Small dike 32 Hunch 33 Partition wall, dividing wall, boundary wall, or stop wall, end wall for adjacent separation 34 Connection opening, passage between adjacent rooms at the lower part of the partition wall 35 Retaining wall 36 Front wall 37 Existing dike top raised concrete part 38 Intermediate wall, reinforcement wall 39 Resistance to tsunami wave power 40 House 41 Landside side wall

Claims

1. The height of the shelter will be the same as the top height of the existing embankment, and a long, horizontally shaped tsunami evacuation shelter with a base dimension larger than its height will be installed at the back of the shelter. By making the top of the tsunami evacuation shelter a nearly horizontal, flat surface, overflow will be made into a smooth water flow and eddy currents that can be drawn in will be reduced. The shelter will act as a shield for the embankment in front of it, and by being located at the back of the shelter it will be able to avoid the direct wave force of a tsunami. It will also act as a rear shield to support the embankment by bearing the overturning moment of the embankment, and these reinforcements will prevent the embankment from collapsing, being damaged, or breaching. The shelter will be able to be extended in the extension direction by utilizing the long extension of the embankment, and will function as an entrance / exit when a tsunami enters. This tsunami evacuation shelter is a dual-purpose structure that is integrated with a levee and has an airtight, upper-closed hollow structure that has the necessary air volume to survive underwater even if it is submerged by a tsunami, and has an entrance on the land side that is wide enough to allow two people or two wheels to jump in at the same time, making it a non-sealed structure.As this does not subject the walls of the structure to a large bending moment, the wall thickness can be made relatively thin, but even so, the weight of the concrete structure exceeds the buoyancy force acting on the structure when submerged, so it will not float up.End walls are provided at any two ends in the length direction to form a hollow box shape, and the front and back of the shelter overlap with the levee to reinforce the levee and prevent it from collapsing against tsunami wave force.

2. A tsunami evacuation shelter as a dual-purpose structure integrated with a levee as described in claim 1, characterized in that the area within the shelter near the open structure entrance is surrounded by a pool wall that is slightly higher than the entrance height in a U-shape when viewed from above, or that extends to the end walls at both ends to prevent the intrusion of drifting debris and form a temporary pool for tsunami water, thereby contributing to the damper that can soften the direct hit of the tsunami wave, and in the event of a large tsunami, the water level is raised to the pool wall height of the pool, preventing the air from the floor height of the shelter from escaping as internal air, i.e., by using compressed air, the volume of survival air retained internally can be increased compared to an open structure without the enclosure.

3. A tsunami evacuation shelter that is integrated with a levee and is a dual-purpose structure as described in either claim 1 or claim 2, characterized in that the top of the tsunami evacuation shelter is used as a levee management road or for general vehicle and bicycle traffic.

4. A tsunami evacuation shelter that is an integrated and dual-purpose structure with a levee as described in either claim 1 or claim 2, characterized in that it is designed to accommodate even the highest tsunami height, while the top height of the existing levee has a height limit, and that it can be installed within the range of the overturning resistance moment of the tsunami evacuation shelter behind it by installing a small levee on the top, or by incorporating the top of the existing levee and raising it, or by extending the shelter to the rear, thereby increasing the overturning resistance and allowing the installation of an even higher small levee.

5. A tsunami evacuation shelter that is integrated with a levee and serves as a dual-purpose structure as described in either claim 1 or claim 2, characterized in that the shelter is extended in the direction of residential houses to facilitate more rapid evacuation, and is expanded or extended in a direction perpendicular to the levee.

6. A tsunami evacuation shelter that is an integrated and dual-purpose structure with the levee described in Claim 3, characterized in that the shelter is extended in the direction of residential houses to facilitate more rapid evacuation, and is expanded or extended in a direction perpendicular to the levee.

7. A tsunami evacuation shelter that is an integrated and dual-purpose structure with the levee described in Claim 4, characterized in that the shelter is extended in the direction of residential houses to facilitate more rapid evacuation, and is expanded or extended in a direction perpendicular to the levee.

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