Showing posts with label Tsunamis. Show all posts
Showing posts with label Tsunamis. Show all posts
TSUTSU
Most tsunamis have a 'run up' of no more than 1.5 m. Building our shelter on stilts takes care of those easily, especially i
f the columnar supports dont have permanent walls or other obstacles attached to them. Stairs and other light artifacts can be swept away with no strain of the building itself, although we recommend at least one self buttressing set of concrete stairs to allow beach uccupants to climb up to safety. The entire shelter is surrounded by a circular set of steel railing both to allow endangered people to hang on and climb aboard, and for protection of the building itself against floating debris. There are six entry points all around the structure to allow
admission of these people, with 3 doors and 6 windows.As with the Archimede beach resorts,
these structures are much appreciated since they do no block the views nor the access to the beach. Instead they provide shade and interesting paths to the beach itself.
Although the statistical approach is still very imperfect, the probabilities for a bigger tsunami are very real, one for instance that could generate a few run-ups of over 3 meters. In such a case, the shelter is still quite valid since the pressures expected on the shell are well handled by properties that have been known for almost thirty years. The behavior of the steel connectors and panels is entirely predictable in a symetrical arrangement of dodecahedral modules.
Also known is the fact that the 100-year tsunami could have a run-up of over 3 meters, one that would pressure the structure to the point of endangering its columns and their connection to ground or building. In such an occurence, a powerful upsurge on those conn
ectors would allow the entire building to float up thanks to sliding cylinders inserted into a sleeve cast into the concrete columns. Since the building itself has know flotation properties we can safely calculate that a crowd of 200 people can ride up the bigger waves with the building, the latter ajusting to the surge to a height of 3.5 to 4 meters.In the highly unlikely tsunamis that could heave the building beyond the reach if it's cylinders, The shelter would simply detach itself and float inland harmlessly, giving it a chance to pick-up more people in danger. Since the outflow of a tsunami of that size is loaded with debris, the building
would need to resist these pressure. The circular 'bumper7handrail' system will help deflect these problematic floating objects.On the other hand, since the building is truly unsinkable because of the rigid foam in its panels, a worse case scenario would involve perforation of the shell, floating out at sea and a panicking crowd that would collect all on one side, tilting the structure dramatically. This is why additional flotation is provided in the form of plastic drums set under the floor, creating a counter force to the asymetrical loading of the floor. This is also the reason why a second floor is helpful as in such a case water would harmlessly flood part of the ground floor. Nervous occupants could safely go upstairs or even on the roof, awaiting help. It is know that again in the worse case scenario the building would never be far at sea, would be essentially undamaged and could be cran
ed to its former site after inspection of the column system. If high capacity cranes ( 2 x 25-ton+ cap. each) were not available, again the worse case scenario would involve essentially unbolting 60 panels and re-attaching them by hand over the columns, essentially tightening 60 high capacity bolts with box wrenches. Of course in a case like this all the joints would have to be re-sprayed with urethane foam, an operation costing $2000 that can be carried out in one day. It would seem that there would be a lot of grateful volunteers for a job like this, repairing 'mama' after she took care of 200 people!
TSUTSU BASICS
Tsutsu's functionality would command a building that would normally cost at least 3 times more than conventional commercial construction. However in this case the concept is so close to what Archimede builds since 1980 that we can safely assume its cost to be approximately 10% over that of quality local construction. This takes into account a better grade of column pads and reinforcement, telescopic connectors, flotation extras and other equipment (like...a sturdy anchor!) .Now consider these advantages:
- The concept is also a valide hurricane shelter, proven in at least one Force 5 hurricane.
- In its daily incarnation, the building is a superb shell for all kinds of building programs, school, recreative center, administrative bldg., community center etc...Because the same injected foam that provides flotation along with superior tightness of the shell also allows for cheaper air conditioning. Indeed these are essentially the same as the arctic concept developed in the early 80's.
- This is a cliché, of course, but life is priceless. We all had terrible heartaches to see innocent people drown and die as they were carried away along with mountains of floating debris. Those who survived had unbelievable puncture wounds from nails protruding from dislocated boards. Is it not fitting that these populations would deserve a high-tech concept that does not use nails, only a few bolts actually, in a configuration that allows distressed swimmers to climb aboard while totally protecting 200 more people.
TSUNAMI PROBABILITIES
A total of 482 tsunamis have been reported in the 20th Century alone, with at least 133 having a runup greater than 1.5 meters. We know that Japan, the West Coast of South America, Alaska, the Aleutian Islands, Kamchatka, and the Kuril Islands are potential tsunami generating areas. We know that these are the boundaries of major tectonic plates. But what about all the other subplates of the inland seas that have produced also the big destructive tsunamis and for which we have not established seismic gaps?
Where in the Pacific Ocean can we expect the big tsunamis in the 21st Century other than the areas mentioned? Let us be more specific. There are many tsuna A total of 482 tsunamis have been reported in the 20th Century alone, with at least 133 having a runup greater than 1.5 meters. We know that Japan, the West Coast of South America, Alaska, the Aleutian Islands, Kamchatka, and the Kuril Islands are potential tsunami generating areas. We know that these are the boundaries of major tectonic plates. But what about all the other subplates of the inland seas that have produced also the big destructive tsunamis and for which we have not established seismic gaps?
Where in the Pacific Ocean can we expect the big tsunamis in the 21st Century other than the areas mentioned? Let us be more specific. There are many tsunamigenic regions that have shown high density of seismic energy release and where large future tsunamis can be expected. For example, one such area is a segment of the Peruvian coastal region between 8.5° S and 14° S. This is a region of extremely high seismic energy release and site of large but infrequent historical tsunamis. Other parts of the South American seismic belt are tsunami gap regions and these regions in the 17th, 18th and 19th Centuries produced several destructive tsunamis, destroying such towns in Chile as Arica, Antofagasta and Valparaiso. There is also a great potential for another destructive tsunami on the Pacific side of Colombia, in the vicinity of the State of Narino. The west coast of Mexico can be expected to experience larger tsunamis. Large destructive tsunamis can be expected again in the Moro Gulf in the Philippines, in the Celebes and Sulu Sea, in the Java Sea and elsewhere in the South West Pacific.
migenic regions that have shown high density of seismic energy release and where large future tsunamis can be expected. For example, one such area is a segment of the Peruvian coastal region between 8.5° S and 14° S. This is a region of extremely high seismic energy release and site of large but infrequent historical tsunamis. Other parts of the South American seismic belt are tsunami gap regions and these regions in the 17th, 18th and 19th Centuries produced several destructive tsunamis, destroying such towns in Chile as Arica, Antofagasta and Valparaiso. There is also a great potential for another destructive tsunami on the Pacific side of Colombia, in the vicinity of the State of Narino. The west coast of Mexico can be expected to experience larger tsunamis. Large destructive tsunamis can be expected again in the Moro Gulf in the Philippines, in the Celebes and Sulu Sea, in the Java Sea and elsewhere in the South West Pacific.
TSUNAMI 'FLOATING SOLUTION'
FLOATING HOUSES
TSUNAMI SHELTER COLUMNS - A Suggestion By A Blogger
Posted on Sunday 23 January 2005
by Robin T
May I offer my suggestion for a Tsunami shelter suitable for single family dwelling? It uses economical, appropriate technology and is available to all neighboring countries - namely a Coconut Palm tree trunk.
As will be well known already, coconut palms are built to withstand typhoon winds by flexing with the wind force. However, you probably cannot just shin up a palm tree when a Tsunami threatens. These trees they have a relatively shallow ball root system (around half a metre deep) spreading up to 2 metres in radius. Whilst this may withstand the average wind onslaught it is unlikely to withstand torrential flooding because the ground is washed away and turned into a waterlogged mire of sand and mud with no significant strength. Similarly, when the palm gets too old and tall and is likely to be uprooted naturally by the wind and replaced by younger fry. Most trees suffer a similar fate. However, these old palm trunks can reach 10 straight metres or more and in the vertical position are surprisingly strong yet flexible (also very heavy). If not already freely available as fallen debris, they can be purchased for a modest sum as old trees become increasingly uneconomical for coconut production. Coconut wood is often derided as a building material because of its habit of delaminating and weakening as it ages. This doesn’t seem to happen with tree trunks.
Excavator machines are probably already on site under government clearance operations. A simple swipe from a bucket will dig a 2.5 metre deep hole in which to place this palm trunk (or you can dig it manually). The excavator can also help lift and position the trunk, which could weigh as much as 2 tonnes. Note that the base of the trunk must be encase fully in stout polythene (non bio-degradable) and duck tape to prevent termite destruction. Better still, it can be painted with hot tar. Depending on funds available, a reinforced concrete base and collar may be used for additional strength (but IMHO is probably icing on the cake). Also if funds permit, the trunk should be treated with wood preservative (old diesel engine oil can help if expensive preservative is not available). The ground must then be filled in, watered and tamped down. I would also created a raised circular ground area around the base of say half a metre high and 2 metres diameter supported by a ring of used beer bottles, crushed concrete of similar device. Cap this area with cement and plant soil retaining grass around the edge. The idea is to keep the ground around the trunk from softening as long as possible. A Tsunami flood generally subsides within half a day. Even a heavy monsoon does not penetrate a compacted laterite soil more than half a metre except after prolonged soaking of many weeks so the ground supporting the trunk should remain solid. Compacted laterite is almost like concrete.
The trunk should be equipped with simple steel spikes made from 8mm rebar drilled and hammered into holes either side into the trunk (like an electricity pylon). The top of the trunk should be equipped with a simple platform for the refuge of a family of 4 – 6 adults. As a wonderful bonus, this platform may be equipped with a small water storage tank with an inverted conical roof. This can serve as a sun-shelter and fresh water container. The tank should be made of polythene or cement/clay “ong” not PVC which becomes brittle. The family may have to stay up there for 24 hours. A major problem for post flooding is an adequate supply of drinking water so the tank should be circular of about 200 litres in size for 10 days supply. The height of the trunk should be at least 6 metres or more. The total cost should be around 2000Baht in materials assuming some government guidance.
I don’t claim my suggestion is 100% perfect but it may offer an improved survival rate for those living in coastal flat areas where there is no high ground to run to. Remember that a Tsunami travels at 80 – 100 km/h – highway speeds - so if you can see it coming you are too late to run. The trunk should have a life span of at least 10 years in my own experience and if properly built and preserved against insects, may last 50 years – who knows? I would apply old engine oil to the structure once a year and clean the tank, make it a family ritual. Termites hate engine oil.
As with any design that concerns human safety I would insist that my suggestions are reviewed by the competent local authority and a licensed Thai structural engineer. It would make a great research project for a technical university.
I, for one, would bet my family’s life on this option in the absence of an alternative. This method works successfully for offshore oil platforms by the way. I would not recommend more that a single leg for this platform (called a monopod) simply because of the danger of large floating debris becoming entangled in the additional legs and adding to the stress. I might also suggest some simple vortex breaking device connected between the spikes to prevent the pole oscillating during freak winds – very easy to do. Do not put the pole near any building that is likely to collapse, or it might topple the pole.
I have many friends and relations how have lost love ones so I hope my contribution may be of help. No one can be blamed for this disaster as events in the Indian Ocean are rare. This event was by far the largest human catastrophe of this type since records began (17 century) yet such events on a small scale are common in the pacific and the western coast of Sumatra. There is an average of 2 Tsunamis spreading across the pacific every year. Because of this, the USA has had a chain of highly sophisticated sensors protecting the whole of its western coast installed for many years. It will take a long time and a billion dollar budget to protect the Indian Ocean to the same degree (how can that be funded?). In the meantime people need some peace of mind.
My sympathies to all those affected
Sincerely
Robin
by Robin T
May I offer my suggestion for a Tsunami shelter suitable for single family dwelling? It uses economical, appropriate technology and is available to all neighboring countries - namely a Coconut Palm tree trunk.
As will be well known already, coconut palms are built to withstand typhoon winds by flexing with the wind force. However, you probably cannot just shin up a palm tree when a Tsunami threatens. These trees they have a relatively shallow ball root system (around half a metre deep) spreading up to 2 metres in radius. Whilst this may withstand the average wind onslaught it is unlikely to withstand torrential flooding because the ground is washed away and turned into a waterlogged mire of sand and mud with no significant strength. Similarly, when the palm gets too old and tall and is likely to be uprooted naturally by the wind and replaced by younger fry. Most trees suffer a similar fate. However, these old palm trunks can reach 10 straight metres or more and in the vertical position are surprisingly strong yet flexible (also very heavy). If not already freely available as fallen debris, they can be purchased for a modest sum as old trees become increasingly uneconomical for coconut production. Coconut wood is often derided as a building material because of its habit of delaminating and weakening as it ages. This doesn’t seem to happen with tree trunks.
Excavator machines are probably already on site under government clearance operations. A simple swipe from a bucket will dig a 2.5 metre deep hole in which to place this palm trunk (or you can dig it manually). The excavator can also help lift and position the trunk, which could weigh as much as 2 tonnes. Note that the base of the trunk must be encase fully in stout polythene (non bio-degradable) and duck tape to prevent termite destruction. Better still, it can be painted with hot tar. Depending on funds available, a reinforced concrete base and collar may be used for additional strength (but IMHO is probably icing on the cake). Also if funds permit, the trunk should be treated with wood preservative (old diesel engine oil can help if expensive preservative is not available). The ground must then be filled in, watered and tamped down. I would also created a raised circular ground area around the base of say half a metre high and 2 metres diameter supported by a ring of used beer bottles, crushed concrete of similar device. Cap this area with cement and plant soil retaining grass around the edge. The idea is to keep the ground around the trunk from softening as long as possible. A Tsunami flood generally subsides within half a day. Even a heavy monsoon does not penetrate a compacted laterite soil more than half a metre except after prolonged soaking of many weeks so the ground supporting the trunk should remain solid. Compacted laterite is almost like concrete.
The trunk should be equipped with simple steel spikes made from 8mm rebar drilled and hammered into holes either side into the trunk (like an electricity pylon). The top of the trunk should be equipped with a simple platform for the refuge of a family of 4 – 6 adults. As a wonderful bonus, this platform may be equipped with a small water storage tank with an inverted conical roof. This can serve as a sun-shelter and fresh water container. The tank should be made of polythene or cement/clay “ong” not PVC which becomes brittle. The family may have to stay up there for 24 hours. A major problem for post flooding is an adequate supply of drinking water so the tank should be circular of about 200 litres in size for 10 days supply. The height of the trunk should be at least 6 metres or more. The total cost should be around 2000Baht in materials assuming some government guidance.
I don’t claim my suggestion is 100% perfect but it may offer an improved survival rate for those living in coastal flat areas where there is no high ground to run to. Remember that a Tsunami travels at 80 – 100 km/h – highway speeds - so if you can see it coming you are too late to run. The trunk should have a life span of at least 10 years in my own experience and if properly built and preserved against insects, may last 50 years – who knows? I would apply old engine oil to the structure once a year and clean the tank, make it a family ritual. Termites hate engine oil.
As with any design that concerns human safety I would insist that my suggestions are reviewed by the competent local authority and a licensed Thai structural engineer. It would make a great research project for a technical university.
I, for one, would bet my family’s life on this option in the absence of an alternative. This method works successfully for offshore oil platforms by the way. I would not recommend more that a single leg for this platform (called a monopod) simply because of the danger of large floating debris becoming entangled in the additional legs and adding to the stress. I might also suggest some simple vortex breaking device connected between the spikes to prevent the pole oscillating during freak winds – very easy to do. Do not put the pole near any building that is likely to collapse, or it might topple the pole.
I have many friends and relations how have lost love ones so I hope my contribution may be of help. No one can be blamed for this disaster as events in the Indian Ocean are rare. This event was by far the largest human catastrophe of this type since records began (17 century) yet such events on a small scale are common in the pacific and the western coast of Sumatra. There is an average of 2 Tsunamis spreading across the pacific every year. Because of this, the USA has had a chain of highly sophisticated sensors protecting the whole of its western coast installed for many years. It will take a long time and a billion dollar budget to protect the Indian Ocean to the same degree (how can that be funded?). In the meantime people need some peace of mind.
My sympathies to all those affected
Sincerely
Robin
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