Tsunami evacuation shelter that can save you even in a tsunami as high as 20 meters.

Abstract

The 320,000 death toll from tsunamis has not decreased by a single person in the last 14 years. We will provide shelters that will save you even if submerged by a tsunami. [Solution] The tsunami evacuation shelter consists of an underground shelter body 1 that is not subjected to the force of tsunami waves, and a horizontally elongated air tower 2 above ground that can withstand the wave force. It is an open structure with an entrance 3 on the side wall, and a water intake manhole structure that is 10 cm higher than the entrance height. When submerged, water is allowed to overflow, and when the internal pressure and external water pressure become equal, the water level rises to the height of the water intake manhole, creating an airtight space, and the air necessary for survival is compressed and does not escape. The water that flows in and accumulates at the bottom is automatically discharged by a siphon or powered by a submersible pump. Individual modifications are possible to accommodate tsunamis of 20m or more by expanding the shape.

Description

Technical Field

[0001] The present invention relates to a tsunami shelter in an underground form that avoids powerful tsunami waves in the gardens, open spaces, and grounds of houses in areas where tsunamis strike. It is composed of an underground shelter body and an above-ground air tower, and has an open entrance and is a non-sealed structure. It is assumed that even when submerged in repeated tsunamis, it can create a closed space inside and maintain the survival air volume while compressing it, and enables evacuation within 5 minutes.

Background Art

[0002] The Cabinet Office's 2011 tsunami prediction project predicted 320,000 deaths from a tsunami caused by a massive Nankai Trough earthquake within 30 years. Fourteen years have passed, half that time already gone, and it remains to be seen how many more people have been saved; the results are eagerly awaited. A comprehensive review is necessary. Building only 10-meter high seawalls would collapse the national budget due to the long coastline. Furthermore, they would block the view of the sea, leading to significant opposition from residents. However, doing nothing is not an option either. Tsunami towers are enormously expensive. Relocating to higher ground would require even greater expense and effort. The fact that a 10-meter tsunami could strike in five minutes, yet the calls to "run away!" and television evacuation drills showing residents fleeing to higher ground are completely misguided. The wasteful spending of the budget is appalling. Even a small wave of just 0.3m can cause you to be swept away and drowned if you go outside, so it is clear that you cannot escape. A search on the patent information platform yielded 32 results for "tsunami shelter," of which 3 were relevant. A search for "underground shelter" yielded 5 results, but the content was similar to the 3 mentioned above. Patent document 1, although covered with soil, cannot withstand the water pressure of a tsunami, and the upper entrance 14 cannot withstand the water pressure of a 10m tsunami, will break, and you will drown inside. The side entrance 25 will also have tsunami mud and sediment accumulating outside the door, making it impossible to open by hand. Eventually, you will suffocate. Patent document 2 has a large underground space, and it will easily float up due to liquefaction caused by a prior earthquake. Even the buoyancy of the groundwater level in normal times will easily cause it to float up, making it dangerous as it will be directly hit by a tsunami. Furthermore, the water and sediment volume above the hatch will prevent you from lifting the entrance cover and escaping. Patent Document 3 also describes a larger underground space, which would float due to normal buoyancy and be vulnerable to direct hits from tsunamis. The accumulation of water and sediment above the hatch would prevent the entrance cover from being lifted, making escape impossible. The waterproof doors on the sides would also be blocked by sediment and could not be opened. This invention differs in that it involves installing the shelter body underground and an air tower above ground, and has enough weight to prevent it from floating due to buoyancy. Furthermore, the entrance is open and does not have an expensive door. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Utility Model Registration No. 3193067 [Patent Document 2] Utility Model Registration No. 3177047 [Patent Document 3] Utility Model Registration No. 3181620

[0004] [Non-Patent Document 1] Nakagawa Kogyosho Paper [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] High seawalls are effective against the massive tsunami that will accompany the impending Nankai Trough mega-earthquake. However, building them to a maximum height of 34 meters is impractical. Moreover, high seawalls require a large budget and face significant opposition from residents due to concerns about obstructing the ocean view and blocking sea breezes. Waiting for countermeasures to progress is tantamount to waiting for death. We must consider shelters that can save people even if submerged by a tsunami.

[0006] The Cabinet Office predicts that the tsunami will kill 320,000 people, but we await the announcement of the results of the measures taken over the past decade to determine how many tens of thousands of lives have been saved. Half of the 30-year timeframe for its occurrence has already passed. It could have happened by now. For some reason, we feel lucky that it has happened so far. However, in reality, the people will continue to live in fear of death for the remaining time. Even after 30 years, the fear will continue until they die. If the tsunami is inevitable, the people of Tokai and western Japan will never cease to fear death and will continue forever. Personally, I think that death is the end, but survival means it will continue forever. What an incredibly resilient people the Japanese people are. I don't think we'll repeat the mistakes of the Tokyo Electric Power Company's Fukushima Daiichi nuclear power plant, but are we perhaps relying on divine intervention and superstition, believing that the tsunami won't come, won't be discovered, and simply won't happen until it does? The former president of Tokyo Electric Power Company was found guilty in court for neglecting to take measures despite being able to foresee the tsunami. Those in charge of the levees have an obligation to raise them to more than 10 meters if a 10-meter tsunami is foreseeable, in order to avoid being indicted and charged. However, it feels like no progress is being made. If measures are not taken despite the tsunami being foreseeable, it is easy to imagine that the heads of the national and local governments in charge of the levees will be found guilty, as was the case with the Tokyo Electric Power Company president who was found guilty. I'm tired of hearing the same old excuse that it was unforeseen. Residents remain in danger of losing their lives and are living in fear. Isn't this similar to the current situation where Israel treats the lives of the people in the Gaza Strip lightly and leaves those who are at risk of death unattended? In addition to raising the levees, other proposed tsunami countermeasures include tsunami towers and relocating to higher ground, but especially with tsunami towers, how many of the 320,000 people will actually be able to reach them during the middle of the night in winter when the greatest damage is predicted, while everyone is fast asleep? Even a small wave of just 0.3 meters can sweep you off your feet and cause you to drown. It is dangerous to go outside your home. The cost-effectiveness is extremely low, or even zero. Despite the prediction that the greatest damage will occur in the dead of winter at midnight, the countermeasures do not take the worst-case scenario into account. The measures also leave behind the elderly, pregnant women, and wheelchair users who will not be able to reach the building in the dead of winter at midnight, and the budget allocation using taxpayers' money is extremely unfair. The entrance to the tower is locked with a fence to prevent intruders. The costs of on-site and overnight caretakers are high, and even if there is an elevator, emergency power, statutory inspection costs, and replacement costs will be insufficient. Imagine the resentment of those who miss the elevator, and the frustration of those who go up but are unable to come down.Unless it's a 35-meter-tall tsunami tower, survival is unlikely. Raising the tower's height to accommodate unexpected increases would double the construction costs. If the height is insufficient after each revision of predictions, it becomes a dangerous, even useless, structure. It's a complete waste of taxpayer money. There's absolutely no guarantee of survival at any given height. If someone dies, it's simply because the height was unexpected. Moreover, the townscape is easily swept away and destroyed. At the very least, residents should not be put at risk of losing their lives. This does not contribute to strengthening the nation's resilience. We must learn from past examples, especially the Great East Japan Earthquake. In the case of relocating to higher ground, only the town hall is moved, not the entire town. Is it acceptable to abandon the vibrancy of the town and its residents? The image of a father desperately searching for his 15-year-old daughter during the recent Noto flood was heartbreaking. He was relieved when she was found by chance on a fishing boat 10 days later, but it showed just how tragic it is when a family is separated. Even if town hall employees are rescued, tragedy awaits if their families and many ordinary residents remain missing. For the remaining 16 hours of the day outside of working hours, they are on the plains. What are they protecting? Even if there are important documents, digitalization would eliminate the need for warehouses. As for resident registers, the residents are no longer alive. The number of people, costs, and duration of the search are limitless. Relocation to higher ground needs to be reconsidered, or if relocation is to be carried out, taxpayers should be moved first, and measures to save the lives of residents on the plains below and the collection of wisdom must be carried out in parallel.

[0007] Even if the construction of high seawalls is not possible, the existing seawalls installed along the coastlines of all coastlines throughout Japan by our predecessors will serve as a minimum level of breakwater. However, low seawalls cannot save the lives of townspeople. Therefore, we believe that even if submerged by a tsunami, people can at least survive if they can retain air. Compared to the Great East Japan Earthquake and Tsunami, the Nankai Trough mega-tsunami is predicted to have six waves repeating every six hours, so the submersion time will be limited, and the tide will quickly recede, supplying air. The seawalls are heavy and rigid enough. Only the height is insufficient. On the other hand, shelters that contain air are useful for human survival. People do not want to leave their towns, and we must not take the lives of young people, especially elementary school students with a future ahead of them. The news of Okawa Elementary School in the Great East Japan Earthquake spread around the world in an instant. The surviving teachers are also suffering in court. We must not let this suffering be repeated. Even if the townscape is sacrificed, it will be temporary, and as long as people are alive, they can rebuild their lives. The more people who survive, the greater the expectation of rebuilding a new town. For example, consolidating land and replacing it with tall, sturdy buildings is also possible in the opposite sense. The town will be reborn as a new, disaster-resistant city. The safety of people's lives and community life will be ensured.

[0008] Therefore, realizing accessible, inexpensive tsunami shelters that save many lives, are readily available, and ensure the safety of people's lives and communities throughout 24 hours, including the safety of residents, given that most people will be at home during the peak of the disaster at night, can be said to be a key to solving the problem. Tsunamis can strike anytime, anywhere, and at any time. In areas where tsunami evacuation is difficult, the idea of ​​"getting away" is advocated, but it's obvious that you'll survive if you get away, and most people cannot get away. Don't be fooled. In particular, vulnerable people who are at risk of disaster evacuation, such as the elderly, pregnant women, and wheelchair users, cannot get away. Saying "it's your own responsibility and we don't know what to do" is an abdication of responsibility and is far too cruel for the government. On the other hand, looking at daily life, cars are indispensable for work, shopping, and going to the hospital, especially in rural areas. It would be great if you could escape far away by car, but it has been proven that concentrating on main roads will result in getting caught in traffic jams. While the timing of the tsunami is unknown, the Cabinet Office predicts that the tsunami accompanying the upcoming Nankai Trough mega-earthquake will reach a maximum height of 34.4m, resulting in 320,000 deaths and 1 million casualties. Coastal areas are expected to experience a 10m-high tsunami in 2-5 minutes, with the greatest damage occurring in the middle of winter, in the dead of night. Ten years have passed since the initial announcement; how many tens of thousands of those people have been saved? Recently, footage of the massive tsunami from the Great Kanto Earthquake has been discovered. Warnings are rampant, but the lack of visible faces of those truly responsible for saving countless lives is a fundamental reason why the problem remains unresolved. There is endless discussion, consideration, and research, creating a false sense of accomplishment and self-satisfaction, but this is an avoidance of responsibility. This is known as the Odawara Council. The job is to produce results. Nevertheless, evacuation centers serve as temporary refuge for 320,000 people. It is now necessary to verify and disclose whether there are enough shelters for everyone. We await the announcement of the progress on land acquisition and construction of the crematorium. Cremation is impossible without identification documents. Administrative procedures such as DNA testing, dental matching, and fingerprint matching can take 1 to 3 years, and the construction of cold storage facilities to prevent decomposition is also being rushed. In times of emergency and major disasters like this, the government should actively promote the effectiveness of My Number cards with facial photographs for identification. I want to believe they don't intend to leave it like this forever. Do they lack wisdom? If they deal with this quickly, people can live each day in peace for much longer. The responsibility for leaving it like this for 10 years is not light. But since there is no one in charge, they can't really say anything.The tsunami from the Great East Japan Earthquake struck as early as 15 minutes after the earthquake, and often an hour later, giving people time to evacuate. However, tsunamis from the Nankai Trough mega-earthquake and the Sea of ​​Japan mega-earthquake will have a steeper rise in their waveforms, making this impossible. A sudden strike like the one off Okushiri Island tsunami, which occurred in just one minute, leaves no time to evacuate or even have a buffer. We should have learned this from actual tsunamis. Six waves will repeatedly strike over a period of six hours. Since we don't know when it will strike during the day, we must be prepared 24 hours a day. However, despite the unpredictable and cruel nature of tsunamis, they always follow a natural order and rule: they strike after the shaking of an earthquake, and they have a sense of justice that warns us in advance with receding tides and roaring sounds. We must find a way to cope with this and respond. If the tsunami strikes five minutes later, assuming the shaking subsides two or three minutes after the earthquake, then subtracting that leaves us with three or two minutes to escape, which is either possible or impossible. Spending time and budget on accurate earthquake analysis, indulging in self-satisfaction by making it their job, and then having evacuation warning systems issued as quickly as three minutes after an earthquake is often too late. Even a primary school student could understand that. Is it to avoid being told later by scholars that it wasn't accurate? They should know that it's of no use to residents on the life-or-death boundary in coastal areas. A loud siren or announcement announcing the occurrence of the largest possible earthquake would suffice, but it should be automatically transmitted instantly, following the example of Israel and Palestine's missile warning sirens that sound seconds later. The devastation caused by tsunamis is orders of magnitude greater than that of missile strikes. Those responsible for creating systems that are supposed to be accurate are responsible for their accuracy, but they are not responsible for whether they will actually save lives. Even after the tsunami warning following the Tonga volcanic eruption, most people said they did not evacuate, even though a ship capsized in Kochi. Unless a loud siren sounds immediately, people won't be able to take action. In an earthquake, one must be prepared to make immediate judgments and take self-defense measures based on the magnitude of the shaking, and this preparation must be constantly practiced. One might say that if you die, you won't have any regrets, but to avoid regrets, you need to decide in advance what you would do in such a situation. It seems that the switch to avoiding danger doesn't really turn on until the roaring sound, the shaking of the ground, and the high waves are right in front of you. In the cold winter, resignation takes precedence and thinking stops. There's no time to change out of your pajamas while bathing or sleeping.Just getting a fussy child to wear shoes takes at least five minutes. There's no time to think. You have to grab your emergency backpack and run out. I don't know if it's their true feelings, but it's true that many people have given up because they don't have much time left. Of course, we must break free from the bias that "I'll be fine, I'll be okay." Instant, unconditional reflexes and repetitive action training are necessary. Housing conditions also play a role. In ordinary houses, they'll be blown to smithereens, with no chance of survival. In sturdy apartment buildings, it might seem that you'll be safe on a higher floor, but there's no guarantee that the tsunami height will be less than the predicted height. People tend to think they'll be safe by evacuating vertically or to the roof, but in reality, buildings lower than the tsunami height, or their rooftops, will be swallowed whole by the tsunami. Imagine the terror and merciless cruelty of the approaching tsunami. There was a trial after people died while evacuating to the roof of a local bank. What is the government thinking? Is an evacuation plan that simply says "get away" really a good idea? Assuming that people are at home for half of the 24 hours, evacuation is not easy in areas without tall, sturdy buildings nearby. Nevertheless, people must anticipate danger 24 hours a day, including when they are at home, at work, at school, or commuting, even in the middle of the night in the dead of winter. In any case, setting up evacuation shelters near residents is a step towards solving the problem, including providing peace of mind. On the other hand, for those who cannot wait for a tsunami that may strike tomorrow, and for those who prefer self-reliance, setting up their own home or personal shelters would allow for instantaneous evacuation and contribute to the solution. If people can feel safe for at least 12 hours at night, their chances of survival can be said to have risen to 50%. The chances of survival improve with each small amount of safety and location. There are plenty of potential locations, such as workplaces, schools, roadside stations, farmland, and vacant lots. Searching for potential locations while taking a walk can also be fun. The cost per person is a fraction of their savings. Even so, it still feels expensive. It's cheaper than buying a car, yet people can't make the decision. Unless someone tells them they're on the death list, they won't realize it. It's like a carp that's already on the chopping block but still doesn't notice. If it means saving your life, it's worth considering. There's a sense of complacency, thinking the government will take care of it. More importantly, you can't take money to the grave. It's a once-in-a-lifetime decision to use your money wisely while you're alive. It will be appreciated by future generations as an inheritance.Furthermore, shelters located on slightly higher ground, such as those 1 to 2 meters above sea level, offer a higher chance of survival because fresh air can be circulated more quickly. A person, in a state of panic underwater, would likely not last even a minute and would almost certainly die instantly.

[0009] Tsunami evacuation shelters integrated with seawalls and serving as both reinforcement and emergency shelters become readily accessible and immediate for residents in coastal areas. If residents pre-assign their own designated shelter entrances, rapid evacuation becomes possible. We must not forget the family members left behind. Even town hall employees returning from higher ground only work 8 hours a day, meaning they are away from home during the day, and the remaining 16 hours after returning home constitute a significant portion of the dangerous period. Shelters increase the safe and secure time throughout the 24-hour period, improving the effective value of the fair outcome and probability of saving lives. Thus, families should prepare for rapid evacuation, ready for earthquakes and tsunamis to strike at any time within 24 hours. It is crucial that families do not become separated. If they drift and become separated, search and rescue costs will increase several times over. It is important to recognize that this is not simply an individual problem of being lost, but that if families become separated and lost, enormous national costs will be incurred. Tsunamis can strike any time and place, and this provides a 24-hour family-centered training exercise to overcome the bias of thinking "it won't happen to me." Emergency preparedness is only effective when built upon daily thinking and training. There must be no gaps in preparation for tsunamis, which can strike anytime, anywhere. The challenge is to be able to respond anytime, anywhere, 24 hours a day without interruption. For individuals and families to survive, foresight and imagination are necessary. We have the valuable experience of what happened in Eastern Japan. It is easy to foresee that the same result will occur if we leave it to others. Even with a good education, we must not lose our lives due to inaction. What have we thought, what have we done, or tried to do in the last 10 years? Have our evacuation methods and actions actually put us in greater danger? A rigorous administrative evaluation is needed to determine how many promising young lives we have been able to save. As a result, how many people can the government say it has saved in the last 10 years? Will they deny it unless a mountain of 320,000 corpses is built? How unimaginative it is, when the death toll far exceeds the 220,000 deaths from the atomic bombings of Hiroshima and Nagasaki. 320,000 people were thrown into a giant Ishikawa Goemon bath. The biggest problem with this country is that people don't see themselves as being responsible. If we consider the remaining 16 years within the next 30 years, and if 20,000 people are saved each year according to the annual plan, then by 2030, exactly 320,000 people will be saved.This is a naive and horrible mistake. Tsunamis don't strike according to an annual plan; there's a higher probability that 320,000 people will die all at once next year. The government seems to have sensed this all along, as on August 20th of this year (Reiwa 7), they announced that 520,000 people needed to be evacuated in advance. Pre-emptive evacuation is only possible in areas that remain after a partial break, and already half of the 320,000, or 160,000 people, have died. Historical records of earthquakes show that evacuation orders were only issued 32 hours and 2 years in advance. If it happened in a short timeframe, that would be one thing, but if it happens two years later, social activities will be halted and people will be exhausted from waiting. Is it even possible to predict it, or even evacuate? The phrase "you'll be saved if you evacuate" seems like nothing more than a misleading attempt to shirk responsibility. They're calling for a one-week evacuation, but I hope they stop wasting a huge budget on things like building disaster prevention centers and stockpiling food. Building a crematorium for 160,000 people should be the top priority. The construction of freezers to preserve the piles of corpses, reeking of death, is also being rushed. Even if one is lucky enough to survive, all the houses in the area have been swept away, so there is no way to return home; it is a state of utter despair. It would be good if it ended in a rain of relief. The people are not stupid; they are watching. A massive earthquake is inevitable, and if it does not occur within the next 30 years, it will be postponed to the next 30 years. There is no turning back. They will be threatened for the rest of their lives. Of course, one will be saved if they evacuate to a safe place. Will the people continue to be deceived by this pipe dream, this magic spell, this illusion that 320,000 people will be saved? Shouldn't they be presenting methods and measures to actually save lives?

[0010] The Nankai Trough tsunami is projected to occur in coastal areas with six waves repeating over a six-hour period. Assuming one wave per hour, the waves recede for half the time, and when the water level at low tide falls below the shelter entrance, fresh air is automatically replenished and replaced. Therefore, the idea is that one only needs to withstand 30 minutes of flooding. This provides a hint for crisis avoidance. In other words, a regional characteristic value of 0.5 m³ / person·hour can be used. Since children and the elderly have lower lung capacity, it is also possible to arbitrarily interpret this as half of that, 0.25 m³ / person·hour. Humans cannot survive underwater without air. It is almost instant death. Considering this, it can be argued that having a shelter is better than having no shelter at all, and even a small shelter can provide some protection. Realistic values ​​of 0.5 m³, 0.3 m³, and 0.25 m³, with smaller volumes, could also be adopted for any excess capacity. Since tsunamis can occur at any time, seasonal equipment and measures against winter cold are necessary. In this way, the challenges of responding according to region, personnel, season, and time of day can be solved. Consider ventilation and drainage from the entrance to the interior. Low humidity and condensation on a normal basis solves the maintenance and corrosion problems that are common in structures. If there is enough space inside, preparing rubber boats or air mats inside will solve the problem of vulnerable people such as the elderly not getting wet even if there is flooding. Especially in winter, hypothermia is a concern, so air mats or blankets would be appreciated to prevent the body from coming into direct contact with cold water. Consider the optimal response for each season. By enabling evacuation according to the living situation and the number of people, the challenges of an even wider area can be solved. At the fish market, a workplace very close to the sea, it is a tense situation. It is an immediate evacuation, and safety and security can be ensured almost in the course of daily life. It is close, fast, and above all, simple. It is important to say this in order to save the lives of 320,000 people.

[0011] I hear that the review process for building permit applications is very strict. It seems that the review process for shelters is strict even though houses are swept away and destroyed by tsunamis. It is known that even houses that withstand earthquakes will be easily swept away by subsequent tsunamis, so it is foolish to review applications while ignoring one of these factors. If the area where the house was swept away is considered an open space, the building coverage ratio can be cleared. Don't they have that much flexibility? Isn't the incompetence and lack of qualifications of the reviewers one of the reasons why the number of tsunami deaths is not decreasing? Furthermore, even if they can review earthquake-resistant designs, do they lack the ability to review designs for tsunamis that cause so many deaths? Construction of the Tokyo Tower was halted at the time due to height restrictions of about 20 meters, but Prime Minister Kakuei Tanaka suggested that it should be permitted as a structure like a tower or chimney rather than a building, and construction resumed. Tsunami shelters are like chimneys that utilize air, and people do not live in them underwater. Moreover, they save human lives. Shouldn't shelters be classified as structures rather than buildings? Emergency response and rescue shelters should be given special priority. If you go outside your home, your life will be swept away. If you stay inside your home, your life will be swept away with your house. It is unbelievable that there are people who obstruct the provision of shelters and measures to avoid this, people who disregard human life. It is quite something that the inspectors, whose own homes will be swept away by the tsunami, cut off the path of people trying to survive. Who approved the construction of houses that will be swept away? Shouldn't there be standards to prevent houses from being swept away? There needs to be a system to immediately dismiss and expel incompetent or useless inspectors. They are crushing people's hope of saving lives. Inspectors who cannot conduct tsunami inspections because they do not provide design guidelines for houses that can withstand tsunamis, and do not have the ability to provide them, should be expelled. There are earthquake resistance inspections, but there are no tsunami resistance inspections, which account for the vast majority of deaths. Is it because it is inconvenient for them not to be able to do so? Even if a house is strong against earthquakes, it is useless if it is swept away. The procedures are a waste of time, and consulting with them is pointless. They are an utter nuisance. The privileged building inspectors lacked the ability to show measures to prevent disasters, and as a result, they failed to save a single person in the last 10 years, nor did they have the will to save anyone, leaving 320,000 dead. Their guilt is immense. This is a clear example of their disregard for human life. It is a grave sin that they neglected to save lives that could have been saved. It is clear that those who did not complain, or could not complain, are utterly incompetent and harmful. They should be expelled and dismissed, otherwise the death toll will not decrease.It needs to be judged by the people. The Cabinet Office has finally announced that pre-emptive evacuation will reduce the number of deaths by 80%. I have high hopes. However, I would like to advise that, in reality, pre-emptive prediction is impossible, and this cannot be achieved without shelters that can be accessed instantly. In any case, if you stay inside your house, you will lose your life as your house will be destroyed or swept away. Even if you run outside, a 0.3m ripple will sweep you off your feet and you will drown. The only way to survive is to jump into a shelter in your yard. [Means for solving the problem]

[0012] To solve these problems, the present invention provides a tsunami evacuation shelter that can withstand tsunamis up to 20m high. This tsunami evacuation shelter is installed in the garden of a house, an open space, or a ground, and is an airtight, non-sealed structure consisting of an underground shelter body that is not directly subjected to tsunami wave forces and an above-ground air tower with an open entrance on the side, which is said to withstand the buoyancy of a tsunami. The shelter body is made of concrete and has a box-shaped or bottomless box-shaped form that holds the amount of air necessary for survival inside, and the air tower is said to withstand the wave forces of a tsunami, and the entrance height inside It features a water intake manhole surrounded by a higher vertical wall and base plate, which, when submerged, allows water to overflow into the interior from the height of the vertical wall apex of the water intake manhole, but mitigates the direct fall and intrusion of a sudden volume of water, and allows evacuation into the interior through the space separated from the top plate, and the amount of overflow water is accumulated at the bottom of the shelter body, and when the internal water pressure and the external water pressure of the tsunami become equal, the water surface fills at the height of the vertical wall apex, creating an upward-convex closed space, thereby preventing the internal air from escaping and allowing survival air to be retained while being compressed.

[0013] Furthermore, the air towers with low entrance heights are made of concrete, and the overturning moment due to tsunami wave forces is resisted by the weight of the concrete and the rectangular shape, which minimizes the width of the surface directly receiving the tsunami, thereby increasing resistance to overturning in the longitudinal direction. The amount of overflow water accumulated at the bottom of the shelter body due to repeated tsunamis can be discharged by a siphon or submersible pump, and the entrance height is designed to allow escape from the mud layer deposited by the tsunami and also to allow escape from the area flooded after the tide recedes.

[0014] Furthermore, the air towers with high entrances are made of steel or a combination of steel and concrete, the surface directly receiving the tsunami is made as narrow as possible to withstand the overturning moment caused by tsunami wave forces, the base anchors resist overturning, the amount of overflow water accumulated at the bottom of the shelter body due to repeated tsunamis can be discharged by a siphon or submersible pump, and the entrance height is designed to allow escape from the area after the tide has receded. Tsunami evacuation shelters can also serve as shelters against floods, storm surges, typhoons, strong winds, tornadoes, and missile blasts, in addition to tsunamis. [Effects of the Invention]

[0015] If shelters are installed in the gardens of homes, it will be possible to evacuate within 5 minutes of an imminent and, more importantly, sudden tsunami. This eliminates the need for the enormous, unbalanced, and unfair costs of conventional tsunami countermeasures such as relocating to higher ground, high seawalls, and tsunami towers. The savings could then be used to save the lives of many individuals and residents in coastal areas who are anxious about the direct and sudden impact of tsunamis. Moreover, they would be saved from a tsunami that could strike at any time within 24 hours. It would be a miracle from the brink of despair. Families would not be separated, and how fortunate they would be. In any case, if it contributes to saving the lives of residents, the scrutiny of those responsible would be mitigated. The enormous and wasteful expenditure of conventional countermeasures would also be eliminated, and the surplus could be used as subsidies, allowing shelters to be built by the judgment and power of the people, saving and bringing happiness to many citizens who feel abandoned. It is clear that if things continue as they are, people will live in fear of death until a tsunami strikes, or even until they die. For the past 10 years, people have been exposed to the fear of death, suffering mental health problems, feeling like fish on a chopping block, being left in limbo. The government bears a great deal of responsibility for merely threatening people without providing a clear vision for the future. Citizens can find peace of mind in nearby shelters. How fortunate it would be to have safety and security in the future. The total estimated damage is 170 trillion yen, and although it is unknown how much of that is due to human lives, lives are precious nonetheless. We should prioritize disaster prevention with human lives in mind. A glimmer of hope will appear for the 320,000 lives and 1 million victims that had been given up on, or rather, neglected by the government. These individuals are completely unaware that they are among them. They vaguely understand, but since they haven't been specifically named as "you will die," they don't think they will. The government doesn't pay attention to them either. When people see a glimmer of hope, they become more positive. All sorts of ideas will emerge. If continuous 24-hour evacuation throughout the year becomes possible, people can repeatedly practice self-help. They will be able to respond to evacuation instantly. Thanks to those efforts, we can live our daily lives in peace. What a blessing that is. We can expect solidarity in the community. If the enormous budget for Tohoku's reconstruction is further burdened by tsunami countermeasures that are progressing at a snail's pace, it is clear that Japan will sink. Therefore, building a crematorium for 320,000 people and securing the land would have a great economic effect. The fact that damage has been predicted for 10 years, yet not a single person has been saved and no response has been made, is truly a disgrace to the world.It is clear that this will become the target of criticism. Who is responsible? First and foremost, the person responsible must be clearly identified. Are the people so foolish that they do not realize they are being deceived by phrases like "get away with it" and "evacuate in advance"? Progress is slow because of a lack of self-awareness. It is their own fault, and self-help, mutual aid, and public assistance will never progress no matter how long we wait, but first and foremost, we need the firm resolve to protect our own lives. The movements of family members going to school and work should be anticipated every day, allowing them to act together as a family, strengthening their sense of unity and bonds, and preventing them from falling apart. Nearby tsunami evacuation shelters can be considered emergency life-saving facilities that can be rushed into immediately, safe zones, and designated seats that provide emotional support. National budgets should be used for things like this. A tsunami may strike tomorrow, but it is clear to everyone that preparing today will ensure safety for life and for generations to come. It will become a social asset. We can be grateful for the precious time we have now that we are alive. No one would call this a waste of money. If lives are saved, life insurance companies will not go bankrupt. Tsunamis can strike at any time, perhaps even tomorrow, but if national funds are invested in shelter construction, 320,000 lives could be saved. The estimated 320,000 deaths during winter nights while at home are thought to be due to instant death from being swept away along with their homes, or drowning. However, with this invention, even if homes are swept away, lives will not be. It is far too cheap compared to the preciousness of life. Despite the fact that many people will die before evacuation is even possible, and 320,000 deaths are projected, ministries are still busy with television drills to spend the budget, applauding and cheering as one person is lifted by a helicopter. Why don't they think about how to evacuate 320,000 people? The public sees through it, and is utterly disgusted. After 10 years, Japan has declined, becoming adept at self-satisfaction and creating alibis, doing nothing but doing nothing, and is only being ridiculed by the world. Let's make a comeback here. [Brief explanation of the drawing]

[0016] [Figure 1] Bird's-eye view of the shelter, underground perspective [Figure 2] Front view of the shelter, section AA [Figure 3] Front view of the shelter, BB section [Figure 4] Front view of the shelter, CC section [Figure 5]Front view of the shelter, cross-section D-D [Figure 6] Side view of the shelter, evacuation route, siphon, relationship between tsunami height and inner water level [Figure 7] Side view of the shelter, gradient provided at the top edge of the vertical wall [Figure 8] Plan view of the shelter, water intake openings on two sides [Figure 9] Plan view of the shelter, water intake openings on three sides [Figure 10] Front view of the shelter with a steel air tower, cross-section A-A [Figure 11] Front view of the shelter with a steel air tower, cross-section B-B [Figure 12] Front view of the shelter with a steel air tower, cross-section C-C [Figure 13] Front view of the shelter with a steel air tower, cross-section D-D [Figure 14] Side view of the shelter with a steel air tower [Figure 15] Plan view of the shelter with a steel air tower

Embodiments for Carrying Out the Invention

[0017] Common reference numerals are used throughout the drawings and the detailed description to indicate the same elements.

[0018] The destructive power of tsunami waves is tremendous. Minimizing the portion that protrudes above ground is paramount. Ideally, it should be an underground structure hidden beneath the ground. However, assuming a tsunami lasts for 6 hours and consists of 6 waves, the necessary amount of air for survival for the number of people must be secured. Therefore, an air tower should be installed. The tower will protrude above ground. However, there is a limit to its height. If it is too high, there is a risk of it tipping over or collapsing due to the force of the tsunami, and if it is 1 meter high, there will be a level of water accumulation in the area due to the water level at the receding tide of the tsunami, and if it remains submerged in water, fresh air cannot be supplied. If it is any lower, mud will intrude and accumulate, making it difficult to escape from the shelter. Also, if the air volume of the shelter itself is large in an underground structure, buoyancy will act in the summer when the groundwater level rises, and if the underground is too deep, groundwater and excavation volume will increase, making it disadvantageous in terms of construction. The shelter should be as wide and low as possible. The tower must be designed to prevent tipping, as the force of a tsunami is said to be three times that of hydrostatic pressure. External forces will vary depending on the region. The system should be differentiated based on tsunami heights of 10m, 20m, and 30m. The height of the air tower should also be greater than the water level at low tide, or twice the volume of air should be prepared if the water level remains for two consecutive hours. Alternatively, measures such as obtaining air from a tube with a float should be considered. Even if the end of the tube is closed, water pressure will cause water to enter, preventing air from being drawn in, making it difficult in the end. Flaws cannot be seen with a spur-of-the-moment idea. The accumulated water from repeated tsunamis should be drained using a siphon or submersible pump. This will restore the compressed air volume and oxygen level. If the accumulated water is left as is and the system is flooded by the next tsunami, the amount of air inside will decrease.

[0019] A hollow shelter that holds air will float if it is too light. First, to prevent the tsunami evacuation shelter from floating, the weight of the hollow concrete structure must be greater than the buoyant force acting on the structure. The entrance to the above-ground air tower is located in the side wall. The structure is an open structure, and according to Pascal's principle, the air pressure and water pressure inside and outside the shelter are equal, so there is no bending moment on the wall, and the structural wall thickness does not need to be very large. In extreme cases, the wall could be as thin as a sheet of paper. However, the above-ground air tower must withstand the wave force of a tsunami. The necessary cover and wall thickness to withstand salt damage are also required. The structure also needs to have appropriate rigidity and resistance to twisting and deformation. For simplicity, an example of calculations for wall thickness and internal volume using a rectangular shape is shown in the following example. The weight of the underground structure must be greater than the buoyant force. First and foremost, the shelter itself must not float due to buoyancy. Tsunami wave force is said to be three times that of hydrostatic pressure, but this can be significantly reduced to 1.5 depending on the presence or absence of shielding in front and the distance from the coast. Here, we will calculate using three times the force, but reducing it according to local conditions will simplify the design. However, it is important to be aware that reducing it indiscriminately will result in a dangerous design. For concrete air towers, it is recommended to ensure that the width of the base of the underground section is at least twice the height above ground, if possible. If the shelter is made of precast concrete, it can be manufactured in a factory, resulting in good quality and suitability for direct transport. Construction time is also short. However, strict construction management is required at the joints to prevent air leaks in the air-retaining sections. The shelter can be expanded to accommodate additional people. The wave force of a tsunami is said to be three times that of hydrostatic pressure, meaning that a tsunami with a height of 10 meters has a water pressure equivalent to that of a 30-meter wave, making resistance difficult. Nevertheless, there is room for improvement. For example, making the front of the structure facing the coast a pointed triangular wedge shape, or a streamlined shape like the bow of a ship, can help mitigate the force to some extent.

[0020] The application of natural theorems is also useful. According to Archimedes' theorem, air, which is lighter than water, rises in water. The rising air is concentrated in the convex space. According to Archimedes' theorem, the buoyancy force on the shelter is equivalent to the volume of water displaced by the object. Although the hollow shelter containing air is light, the weight of the structure must exceed the buoyancy force. Furthermore, if a 10m tsunami comes, Boyle's law compresses the internal volume to half, and at the same time the buoyancy is halved. According to Pascal's principle, the pressure inside and outside the shelter is equal. Because of this, there is no pressure difference between the inside and outside as in a sealed structure on the walls all around the perimeter of a shelter with an entrance at the bottom of the side wall. Theoretically, a wall the thickness of a single sheet of paper would suffice. According to Boyle's Law, the 10cm above the top of the air tower's entrance creates a sealed space with a horizontal water surface. With a tsunami height of 10m and a water pressure of 2 atmospheres, the air inside the shelter is compressed to half its volume upwards, to one-third at 20m, and to one-quarter at 30m. Consequently, the water level and surface rise, so do not panic. Since the interior is a closed space, the water level rises slowly inside at a rate of 1 / 40th of the outside water level, with the outside water level of 10m being linked to the internal height of half the internal height (0.5m / 2). Air will always remain in the part that connects to the ceiling of the air tower. Buoyancy is equivalent to the volume of air inside the shelter underwater, so the water level inside the shelter rises as the air is compressed. As the internal air is compressed and its volume decreases, it is replaced by water and water weight, thus reducing buoyancy. When setting the capacity of a shelter, it can be considered that the elderly and children with low lung capacity consume half the oxygen, so the excess capacity can be covered or considered as a buffer. Regarding the water pressure burden from a maximum tsunami of 34m in height, there is news from 2013 of a person being rescued 62 hours later from the bottom of a shipwreck at a depth of 30m off the coast of Nigeria. There are also records of free diving to depths of over 100m. Once the first wave is over, the outside water level will drop, and fresh air will replace the water. With a design of 1m³ / hour, there is not much to worry about. First and foremost, the priority is to build shelters without further ado. If we hesitate and do not act, we will be submerged when the tsunami hits us with nothing to protect ourselves from, and without air, we will die in an instant. This is like the Odawara Council, a waste of time, endless deliberation and research, without achieving the goal of saving human lives. The time lost in the last 10 years will never come back. It's just that the tsunami didn't come.As a result, no one was held accountable. Therefore, we can't expect anything from the next 10 years either, because there's no one responsible to produce results. However, I want to believe that if we move forward with courage, we can reclaim the time we spent producing results in the next 10 years.

[0021] Even if the tsunami height is very high, six waves will repeat in a maximum of six hours, creating troughs in the waves where natural air exchange can be expected. This means that the amount of air to be designed can be measured in terms of the tsunami period, or in one-hour increments. In extremely cold conditions, to prevent sudden death from hypothermia, connecting passages should be installed as covered wind tunnels, similar to airplane ramps. Such ingenuity would bring a glimmer of hope to the projected figure of one million casualties, a collection of impersonal lives presented to us. Although there are limitations on transport dimensions, using factory-made precast concrete would allow for higher quality and shorter construction times. The application of rectangular box culverts should be considered. In addition, if air becomes insufficient and breathing becomes difficult, it would be good to place a lifebuoy with a 10m rope attached. This would allow people to surface, breathe, and return after the tide recedes. The rope anchor should be placed inside the shelter wall, and the lifebuoy outside the shelter. Ensure that the total amount of air lost is not equal to the volume of the lifebuoy. However, measures such as coiling the rope are necessary to prevent the lifebuoy from floating up on its own. A shovel is effective for removing accumulated soil. Having U-shaped recessed handles and handrails at the entrance and throughout the interior would be helpful. Since evacuation to the interior is in a narrow space, practice beforehand whether to descend feet first or head first. Having a seat would also make it easier. [Examples]

[0022] Figure 1 shows a bird's-eye view of the shelter, Figures 2 to 5 show a front view from the sea side and its cross-section, Figures 6 and 7 show a side view, and Figures 8 and 9 show a plan view. Both the underground shelter body and the above-ground air tower are made of concrete. In a simplified calculation, assuming the interior space of the underground shelter body is 2.0m wide * 2.5m long * 0.5m high = 2.5m³ (enough for 2 to 3 people), and assuming a high groundwater level, if the concrete wall thickness is 25cm, the buoyancy is the volume of the object displacing the water, which is 2.5 * 3.0 * 1.0 = 7.5t. On the other hand, the specific gravity of reinforced concrete is 2.5, so the weight of the shelter is (2.5 * 3.0 * 1.0 - 2.5) * 2.5 = 12.5t > 7.5t, which is sufficiently greater than the buoyancy, so there is no concern that the reinforced concrete will float. Here, even if it is a box shape without a bottom plate, air will not leak. The buoyancy is 2.5 * 3.0 * 0.75 = 5.625 tons, and the weight is (2.5 * 3.0 * 0.75 - 2.5) * 2.5 = 7.8125 tons > 5.625 tons, meaning it is heavier than the buoyancy even without a bottom plate. The air retention capacity is the same, and the excavation is 25 cm shallower, making construction easier and cheaper, but since it is in contact with the soil surface at the bottom, you have to put up with it getting wet quickly. The air tower is designed in a vertical shape to mitigate the direct impact of tsunamis. It is basically made of reinforced concrete with a wall thickness of 25 cm, protruding 1.35 m from the ground, and has a hollow space 50 cm wide. Considering the depth of the local sediment, the water level at low tide, and the ease of escape, the entrance is provided in the side wall with a height of 50 cm and a width of 50 cm. The water intake manhole that protrudes into the interior is constructed of a vertical wall and base plate that is about 10 cm higher than the entrance height. When submerged, the water level will rise to the height of the top of the vertical wall, creating an upward-convex closed space inside, which will prevent air from escaping and will retain air while being compressed. It is necessary to confirm that the air mass will not escape to the outside. In that case, the height should be increased from 10 cm to 20 cm. A 50cm clearance is maintained between the ceiling panel and the interior, and access is via a ladder and handles. Adding handles above the entrance makes it easier to slide in. The air tower has a weight of (1.0*2.5*1.35 - 0.5*2*1.1)*2.5 = 5.6875t, and adding the underground part of 12.5t brings the total to 18.1875t. The resisting moment is 18.1875*1.5 = 27.28125tm. On the other hand, assuming a height of 10m, the moment of action due to a tsunami is 30t with a wave pressure of 30t and an acting height of 1.35 / 2, resulting in 20.25tm, which is enough to withstand toppling. Calculating the tsunami height in reverse, 27.28125 / 20.25 = 1.364, so it is estimated to withstand a tsunami height of approximately 14m. Taking into account the reduction of wave force due to distance from the coast, obstacles such as seawalls in front, and uphill ground slope, if the coefficient of hydrostatic pressure can be reduced from three times to 2.1 times, it is estimated that it can withstand a tsunami height of approximately 20m. Furthermore, as shown in (Example 2) and (Example 3), simply extending the length of the shelter in the longitudinal direction increases the resisting moment, so it is expected to withstand a tsunami height of 20m. In addition, there is resistance from soil pressure underground, resistance from friction around the sides of the shelter, and resistance from the ground reaction coefficient, so it is unlikely to tip over easily. Even if it were to tip over or tilt, as long as the entrance is not blocked, the structure would not be destroyed and it would likely be able to retain air to some extent. The structure of the water intake manhole is designed so that the vertical walls on both sides run parallel to each other all the way to the back due to the narrowness of the internal space. However, ideally, it would be better to enclose it on three sides to ensure the water surface is filled. Ideally, a gap of about 10 cm should be secured behind the back vertical wall and between it and the back side wall, but securing space on the front side is difficult, so considerations such as making the wall thickness 15 cm are necessary. Also, tapering the top of the vertical walls makes it easier to fill the manhole properly with water and also makes it easier to descend into the interior. Such ingenuity is necessary in many places because the space is narrow. The handle is helpful when descending to the internal bottom plate. The entrance is basically located in the center of the side wall, but it is also possible to shift the water intake manhole to one side and make it a single vertical wall. However, remember that the ideal is to have three sides in the center. As the tide recedes, the water pressure from the tsunami decreases, causing the air pressure inside the shelter to exceed the external pressure. The resulting pressure drop causes the filled hose to automatically drain through a siphon effect, draining the water from the end of the hose outside. The siphon diameter is expected to be around D=150mm. As the volume of water decreases, the internal air will recover its volume due to the pressure drop. Alternatively, the water can be forcibly drained using a submersible pump. This work should ideally be completed before the next tsunami wave. These pipes and hoses should be suspended from anchors above the vertical walls and bent downwards around the center of the water intake manhole. Care should be taken not to place the pipes or hoses on the vertical walls midway, as this may cause the water surface to collapse and prevent the formation of a horizontal water surface. If there are two rows of vertical walls, it is acceptable to install them on the back wall, but if there are three vertical walls, it is recommended to hang them in the middle of the water intake manhole. The amount of survivable air is assumed to be the volume of air inside the shelter itself as a safe bet. However, there is also air in the air tower, and its volume is 0.5 * 2.0 * 1.1 - 1 * 1 * 0.6 = 0.5 m³. This 0.5 m³ added to the shelter's air volume of 2.5 m³ is a valuable figure, but for safety reasons, it is better to estimate using the shelter's air volume and leave the air tower's volume as a margin. Furthermore, according to Boyle's Law, the air volume is halved at a 10 m tsunami height and halved at a 20 m tsunami height, so the amount of water inundation and water weight increases by (2.5 + 0.5) * 1 / 2 = 1.5 t or 2 / 3 = 2.0 t, which contributes to the resisting moment. In other words, this means the flood height will increase. Dividing this by the base area of ​​the shelter, a 10m tsunami would increase the internal water level by 1.5 / (2.0*2.5)=0.3m, and a 20m tsunami would increase it by 2.0 / (2.0*2.5)=0.4m. In both cases, the internal height will rise by more than half of the 0.5m, but this is a level that can be reassuring. However, it is necessary to be prepared for this possibility. But no matter how much it floods, air will always remain above the ceiling, so there is no need to panic or worry. To prevent tipping over, it is necessary to increase the resisting moment. It is a good idea to make the shelter extremely elongated and then perform calculations. Triangular sloping surfaces, wave-dissipating blocks, and concrete blocks on the front of the air tower walls are also effective. Air will be supplied from the air tower, but it will be possible to breathe by sticking your head out of the water above the tower as the tsunami recedes. In areas where the water level does not fall below the height of the tower, the air volume will be enough for two hours, and after three hours, there will be a way to surface and breathe, or the air volume will be enough for up to six hours, or the height of the air tower will be made higher than the height of the water. Another method is to attach a float to a tube with the tip bent from the air tower and breathe through the tube opening at the bottom. Here, the structure, both underground and above ground, has some slight protrusions and dimensional deviations. [Examples]

[0023] Perform the calculation. If the internal length is increased by 0.5m, the dimensions will be 2.0m wide * 3.0m long * 0m high. Assuming 5m = 3.0m3 (enough for 3 to 4 people) and a high groundwater level, if the concrete wall thickness is 25cm, the buoyancy is the volume of the object that displaces water, which is 2.5 * 3.5 * 1.0 = 8.75t. On the other hand, the specific gravity of reinforced concrete is 2.5, so the weight of the shelter is (2.5 * 3.5 * 1.0 - 3.0) * 2.5 = 14.375t > 8.75t, which is well greater than the buoyancy, so there is no concern that the reinforced concrete will float. Now, if we consider a box shape without a bottom plate, the buoyancy is 2.5 * 3.5 * 0.75 = 6.5625t, and the weight is (2.5 * 3.5 * 0.75 - 3.0) * 2.5 = 8.90625t > 6.5625t, so even without a bottom plate, it is heavier than the buoyancy. The air retention capacity is the same, and the excavation is 25cm shallower, making installation easier and cheaper. However, since it is in contact with the soil surface at the bottom, you have to tolerate it getting wet quickly. The air tower has a weight of (1.0*3.0*1.35 - 0.5*2.5*1.1)*2.5 = 6.6875t, and adding the underground part of 14.375t brings the total weight to 21.0625t. The resisting moment is 21.0625*1.75 = 36.859tm. On the other hand, assuming a height of 10m, the moment of action due to a tsunami is 30t with a wave pressure of 30t and an acting height of 1.35 / 2 = 20.25tm, which is enough to withstand toppling. Calculating the tsunami height in reverse, 36.859 / 20.25 = 1.82, so it is estimated to withstand a tsunami height of approximately 18m. Furthermore, simply extending the length of the shelter in the longitudinal direction will increase the resisting moment, so it is estimated that it can withstand a tsunami height of 20m or more. The amount of air available for survival is assumed to be the volume of air inside the shelter itself as a safety measure. However, there is also air in the air tower, and its volume is 0.5 * 3.0 * 1.1 - 1 * 1 * 0.6 = 1.05 m³. This 1.05 m³ added to the shelter's air volume of 3.0 m³ is a valuable figure, but for safety reasons, it is better to estimate based on the shelter's air volume and leave the air tower's volume as a margin. Furthermore, according to Boyle's Law, the air volume is halved at a 10 m tsunami height and halved at a 20 m tsunami height, so the amount of water inundated and the weight of the water increases by (3.0 + 1.05) * 1 / 2 = 2.025 t or 2 / 3 = 2.70 t, which contributes to the resisting moment. In other words, this means the flood height will increase. As shown in Figure 6, dividing by the bottom area of ​​the shelter, a 10m tsunami would result in an internal water level of 2.025 / (2.0*3.0) = 0.3375m, and a 20m tsunami would result in an internal water level of 2.7 / (2.0*3.0) = 0.45m. In both cases, the internal height will rise to more than half of the 0.5m height, but this is a level that can be reassuring. However, it is necessary to be prepared for this possibility. But no matter how much it floods, air will always remain above the ceiling, so there is no need to panic or worry. To prevent tipping over, it is necessary to increase the resisting moment. It is a good idea to make the shelter extremely elongated vertically and perform calculations. Triangular sloping surfaces, wave-dissipating blocks, and concrete blocks on the front of the air tower walls are also effective. [Examples]

[0024] Furthermore, in calculations where the internal length is increased to 4.0m, the volume is calculated as 2.0m wide * 4.0m long * 0.5m high = 4.0m³ (enough for 4 to 5 people). Assuming a high groundwater level, and with a concrete wall thickness of 25cm, the buoyancy is the volume of the object displacing the water, which is 2.5 * 4.0 * 1.0 = 10.0t. On the other hand, the specific gravity of reinforced concrete is 2.5, so the weight of the shelter is (2.5 * 4.5 * 1.0 - 4.0) * 2.5 = 18.125t > 10.0t. The weight is sufficiently greater than the buoyancy, so there is no concern that the reinforced concrete will float. In this case, if we use a box-shaped structure without a bottom plate, the buoyancy is 2.5 * 4.5 * 0.75 = 8.4375 t, and the weight is (2.5 * 4.5 * 0.75 - 4.0) * 2.5 = 11.09375 t > 8.4375 t, meaning that even without a bottom plate, the weight is heavier than the buoyancy. The air retention capacity is the same, and the excavation is 25 cm shallower, making construction easier and cheaper, but since it is in contact with the soil surface at the bottom, one must tolerate it getting wet quickly. The air tower has a weight of (1.0*4.0*1.35 - 0.5*3.5*1.1)*2.5 = 8.6875t, and adding the underground portion of 18.125t brings the total weight to 26.8125t. The resisting moment is 24.1125*2.25 = 54.25tm. On the other hand, assuming a height of 10m, the moment of action due to a tsunami is 30t with a wave pressure of 30t and an acting height of 1.35 / 2 = 20.25tm, which is enough to withstand toppling. Calculating the tsunami height in reverse, 54.25 / 20.25 = 2.679, so it is estimated to withstand a tsunami height of approximately 27m. Furthermore, simply extending the length of the shelter in the longitudinal direction will increase the resisting moment, so it is estimated that it can easily withstand a tsunami height of 20m or more. In summary, as the length in the longitudinal direction is extended from 3m to 4m, the risk of tipping decreases. Naturally, a slender shape with a longer arm length towards the sea provides greater resistance to tipping, so the size should be determined based on this principle and individual circumstances. [Examples]

[0025] If the water depth after the tsunami recedes is as deep as 3.0m, air will not be supplied. Therefore, it is necessary to raise the air tower to a height greater than that. Figures 10 to 14 show examples of ground-level air towers made of steel. In the figures, the thickness of the steel plate is about 1cm, so it is omitted. Let's do the calculations. The interior space of the underground shelter is 2.0m wide * 2.5m long * 0.5m high = 2.5m³ (enough for 2 to 3 people). Assuming a high groundwater level, and assuming the concrete wall thickness of the underground shelter is 25cm, the buoyancy is the volume of the object that displaces water, which is 2.5 * 3.0 * 1.0 = 7.5t. On the other hand, the specific gravity of reinforced concrete is 2.5, so the weight of the shelter is (2.5 * 3.0 * 1.0 - 2.5) * 2.5 = 12.5t > 7.5t. The weight is sufficiently greater than the buoyancy, and there is no concern that the underground reinforced concrete will float up. In this case, if we use a box-shaped structure without a bottom plate, the buoyancy is 2.5 * 3.0 * 0.75 = 5.625 t, and the weight is (2.5 * 3.0 * 0.75 - 2.5) * 2.5 = 7.8125 t > 5.625 t, meaning that even without a bottom plate, the weight is heavier than the buoyancy. The air retention capacity is the same, and the excavation is 25 cm shallower, making construction easier and cheaper, but since it is in contact with the soil surface at the bottom, one must tolerate it getting wet quickly. Assuming a height of 3.0m, the air tower's weight is calculated as surface area * thickness * specific gravity of steel 7.85 = width 0.5 * length 1.5 * height 3.0 * 0.01 * 7.85 = 0.1766t. Adding the 12.5t underground portion, the total weight is 12.6766t, and the resisting moment is 12.6766 * 1.5 = 19.0149tm. On the other hand, assuming a height of 10m, the acting moment due to a tsunami is 30t with a wave pressure of 3.0 / 2, but the cross-sectional area is halved to 0.5 * 3.0, so 30 * 1.5 * 1.5 = 67.5t > 19.0149t, which is far too much to withstand. Therefore, resistance is provided by the pull-out resistance of the anchor bolts. Since the short-term allowable tensile strength of M16 is 53.3kN, if we use M24, the cross-sectional area ratio gives 119.925kN, so 67.5 * 9.8 / 119.925 = 5.5 ≈ 6 bars. Therefore, assuming a tsunami height of 20m, it is necessary to double the strength to 2*67.5, and raising it to M32 results in a short-term allowable tensile strength of 240.68kN, which means that the resisting moment will be less than or equal to 2*67.5*9.8 / 6*240.68 = 0888 < 1.0. Furthermore, simply extending the length of the shelter in the longitudinal direction will increase the resisting moment, so it can be said that it is expected to withstand tsunami heights of 20m or more. The structure of the water intake should ideally have the height of the vertical wall apex about 10 cm higher than the entrance height. Due to the narrowness of the internal space, the vertical walls on both sides are designed to run parallel to each other all the way to the back, but ideally, it would be better to enclose it with three sides to allow water to fill the space. However, it is desirable to leave a gap of about 10 cm between the back vertical wall and the side wall, leaving approximately 40 cm of space on the front side. Let's do the calculations. Assuming the length of the underground shelter's interior is 3.0m, the volume is 2.0m wide * 3.0m long * 0.5m high = 3.0m³ (enough for 3 to 4 people). Assuming a high groundwater level, and assuming the concrete wall thickness of the underground shelter is 25cm, the buoyancy is the volume of the object displacing the water, which is 2.5 * 3.5 * 1.0 = 8.75t. On the other hand, the specific gravity of reinforced concrete is 2.5, so the weight of the shelter is (2.5 * 3.5 * 1.0 - 3.0) * 2.5 = 14.375t > 8.75t. The weight is sufficiently greater than the buoyancy, so there is no concern that the underground reinforced concrete will float up. In this case, if we use a box-shaped structure without a bottom plate, the buoyancy is 2.5 * 3.5 * 0.75 = 6.5625 t, and the weight is (2.5 * 3.5 * 0.75 - 3.0) * 2.5 = 8.90625 t > 6.5625 t, meaning that even without a bottom plate, the weight is heavier than the buoyancy. The air retention capacity is the same, and the excavation is 25 cm shallower, making construction easier and cheaper, but since it is in contact with the soil surface at the bottom, one must tolerate it getting wet quickly. Assuming the height of the air tower is 4.0m, its weight is calculated as surface area * thickness * specific gravity of steel 7.85 = width 0.5 * length 1.5 * height 4.0 * 0.01 * 7.85 = 0.2355t. Adding the underground portion of 14.35t, the total weight is 14.5855t. The resisting moment is 14.5855 * 1.75 = 25,524tm. On the other hand, assuming a height of 10m, the acting moment due to a tsunami is 30t with a wave pressure of 30t and an acting height of 4.0 / 2, but the cross-sectional area is halved to 0.5 * 4.0, so 30 * 2 * 2 = 120t > 14.5855t, which is far too much to withstand. Therefore, resistance is provided by the pull-out resistance of the anchor bolts. Since the short-term allowable tensile strength of M16 is 53.3kN, resistance is provided by the pull-out resistance of the anchor bolts. For M16, the short-term allowable tensile strength is 53.3kN in the reference example, so if we use M24, the cross-sectional area ratio gives 119.925kN, and 120.0 * 9.8 / 119.925 = 9.8 ≈ 10 pieces. Therefore, assuming a tsunami height of 20m, it is necessary to double the strength to 2*120.0, and raising it to M32 results in a short-term allowable tensile strength of 240.68kN, and 2*120.0*9.8 / 10*240.68 = 0.977 < 1.0, which is below the resisting moment. Furthermore, simply extending the length of the shelter in the longitudinal direction will increase the resisting moment, so it can be said that it is expected to withstand tsunami heights of 20m or more. [Examples]

[0026] Although it is a hollow shelter, if cracks occur, air will escape underwater. Air leaks can be fatal. Possible causes include the drying shrinkage of concrete over time, and strain and cracking of the structure due to the massive earthquake before the tsunami, so countermeasures are necessary. Therefore, placing plastic bags such as upward-convex poly bags or airtight sheet bags upside down along the interior walls provides a double layer of safety in case of emergency, preventing air leaks. Personally, I think even garbage bags are useful. The required amount of air is basically 1.0 m³ / person·hour, but for children and the elderly, their lung capacity is lower, so considering half the characteristic value will be helpful if the number of people exceeds the capacity. A lifebuoy, a water-permeable frame to prevent debris from entering the entrance, a small air cylinder, a small oxygen cylinder, a protective board from debris, a flashlight, a smartphone, a radio, hand warmers, bread, water, a portable toilet, a blanket, warm clothing, a disaster preparedness backpack containing garbage bags, a waterproof sheet, a shovel for removing mud accumulated outside, and a lifebuoy with a rope about 10m long attached would be helpful in case of difficulty breathing. You can float up and return to your original location when the tide recedes. Placing water-permeable gabions near the entrance will prevent debris from entering, and when pulled inside, they can be used as seats. Seats and benches can be used as benches. You can easily endure an evacuation of about 6 hours. The lifebuoy should be outside the shelter, and its anchor should be secured inside. It is a good idea to equip the front with protective devices or cushioning devices such as tires to mitigate the impact force of debris. To prevent getting wet from tsunami flooding, it is a good idea to place a platform, a vinyl floating floor, an air mat, or a board inside. In any case, regular awareness campaigns, education, and training are necessary for tsunami countermeasures. We must not take the lives of elementary school children who have a future ahead of them. Protecting them is the greatest responsibility of adults. In areas with declining populations, we can also expect cooperation from residents, such as the provision of vacant lots. [Examples]

[0027] It's not just for able-bodied people; assistance should be provided for the vulnerable and obese. Naturally, the entrances should also be made larger. [Explanation of symbols]

[0028] 1. Underground shelter main body 2 Ground Air Towers 3. Entrance to the side wall of the air tower 4. Water intake manhole located inside 5 vertical walls 6. The top of the vertical wall of the water intake manhole, with a sloped top surface. 7 bottom version 8 heaven version 9. Evacuation Routes 10. A horizontal water surface that rises 10 cm higher than the entrance height when a tsunami enters. 11 handles, handrails, 12 siphon tubes, submersible pump hoses Anchors suspended from the 13th floor panel 14. People evacuating, seats inside the shelter 15 base plate 16 Steel base reinforcing ribs 17 Anchor bolts 18 nuts 19 surface, ground 20 Tsunami from the sea 21. Distance between the side wall behind the vertical wall: approximately 10 cm

Claims

1. A tsunami evacuation shelter to be installed in the garden of a house, open space, or ground, consisting of an airtight, non-sealed structure comprising an underground shelter body that is not directly subjected to tsunami wave forces and an above-ground air tower with an open entrance on the side, which is said to withstand the buoyancy of a tsunami, the shelter body being a concrete box shape or a box shape without a bottom that holds the amount of air necessary for survival inside, the air tower being said to withstand the wave forces of a tsunami, and having a water intake manhole surrounded by a vertical wall and a base plate that is higher than the height of the entrance, when submerged, the aforementioned This tsunami evacuation shelter, designed to withstand tsunamis up to 20 meters high, allows water to overflow into the interior from the height of the vertical wall of the water intake manhole, but mitigates the direct fall and intrusion of a sudden volume of water, and allows evacuation into the interior through the space separated from the roof. The overflow water is accumulated at the bottom of the shelter body, and when the internal water pressure and the external water pressure of the tsunami become equal, the water surface fills the vertical wall at the height of the vertical wall, creating an upward-convex closed space. This prevents the internal air from escaping and compresses it while retaining survival air.

2. The tsunami evacuation shelter according to claim 1 is characterized in that the air tower with a low entrance height is made of concrete, the overturning moment due to tsunami wave force is resisted by the weight of the concrete and the rectangular shape which increases resistance to overturning by extending the longitudinal direction, with the width of the surface that is directly exposed to the tsunami being as small as possible, and the amount of overflow water accumulated at the bottom of the shelter body due to repeated tsunamis can be discharged by a siphon or submersible pump, and the entrance height is set to a height that allows escape from the mud layer deposited by the tsunami and also to a height that allows escape from the area flooded after the tide recedes.

3. The tsunami evacuation shelter according to claim 1, characterized in that the air tower with a high entrance is made of steel or a composite of steel and concrete, the width of the surface directly receiving the tsunami is made as small as possible to withstand the overturning moment due to tsunami wave force, the base anchors resist overhang and prevent overturning, the amount of overflow water accumulated at the bottom of the shelter body due to repeated tsunamis can be discharged by a siphon or submersible pump, and the entrance height is set to a height that allows escape from the area flooded after the tide recedes.

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