A explosive shelter is a place where people can protect themselves from explosions and explosions, such as bombs, or at hazardous workplaces, such as in oil and gas refineries or petrochemical facilities. This is different from the shelter of fall, because its primary purpose is to protect from shock waves and excessive pressure, not from radioactive rain, as a shelter. It also allows for protection to protect from explosions and fallout.
The explosion shelter is a vital protective form of nuclear attack and is used in civil defense. There is a sanctuary on the ground, underground, dedicated, dual-purpose, and potential. Special shelters built specifically for explosion protection purposes (see bunker). Any destination shelter is an existing structure with modified explosive protective properties to accommodate persons seeking protection from explosions. Potentially explosive reservoirs are existing geological structures or features that exhibit explosive properties that are potentially used for protection from explosions.
Video Blast shelter
Design
The blast shelter deflects the explosive waves from nearby explosions to prevent ear and internal injuries against people sheltering in bunkers. While the skeletal building collapsed from just 3 psi (20 kPa) overpressure, the blast shelter is regularly built to survive several hundred psi. This substantially reduces the possibility that a bomb can damage the structure.
The basic plan is to provide a very powerful structure in compression. The actual strength specification should be done individually, based on the nature and possible threats. The typical specification for severe civil protection in Europe during the Cold War was an explosion on a 500 kiloton gun at a height of 500 meters. Such weapons will be used to attack soft targets (factories, administrative centers, communications) in the area.
Only the heaviest rock shelter that will have a chance to survive. However, in the countryside or in the suburbs, the distance possible for the explosion is much greater, since it is unlikely anyone will waste an expensive nuclear device on the target. The most commonly constructed building structures are concrete domes or steel-reinforced arches or located in the basement of a house.
The most efficient explosive shelter is a civil engineering structure that contains buried pipes or large pipes such as sewers or quick transit tunnels. Even this, however, requires some extra to serve properly: blast doors, air filtration and ventilation equipment, secondary exit doors, and airborne checks.
Improvised purpose-built blast shelter usually uses arches or dome made of soil. To form this, narrow thin wooden tents (1-2 meters-wide) are placed inside a deep trench (usually tent tops below the level), and then covered with cloth or plastic, and then covered with 1 -2 meters of earth compacted. This type of shelter is a proper and viable shelter, both in the US and in China. The entrance is built from a thick wooden frame. The explosive valve should be constructed from the tire footprint placed on a thick wooden lattice.
The nuclear bunkers must also cope with underpressure that lasts for several seconds after the shock waves pass, and rapid radiation. Overburden and structures provide great radiation protection, and negative pressure is usually only 1/3 of excess pressure.
Doors should be at least as strong as a wall. The usual design is a trap door, to minimize size and cost. In a dual purpose shelter, which has the use of a secondary time of peace, the door may be normal. To reduce weight, the door is usually made of steel, with a steel lintel mounted and a frame welded to a steel reinforced concrete. The shelter should be placed so that no flammable material is directly outside it.
If the door is on the surface and will be exposed to an explosive wave, the edge of the door is usually opposite-sink in the frame so that an explosion or reflection wave can not lift the edge. If possible, this should be avoided, and doors are built so as to be protected from explosive waves by other structures. The most useful construct is to build a door behind a 90 ° channel in a corridor that has an exit for overpressure.
A bunker generally has two doors, one of which is comfortable, and in peaceful use time, and the other is strong. Naturally, shelters should always have a secondary exit that can be used if the main door is blocked by debris. The door shaft can double as a ventilation shaft to reduce excavation, although this is not recommended.
Large ground blows can move bunker walls several centimeters in a few milliseconds. Bunkers designed for large earth shocks should sprout internal buildings, hammocks, or bean-bag chairs to protect residents from walls and floors. However, most civil-built shelters do not need this because their structures can not withstand enormous shocks to seriously damage the occupants.
The earth is an excellent insulator. In a bunker that is inhabited for a long time, a large amount of ventilation or air conditioning should be provided to prevent hot bites. In bunkers designed for use in warfare, manually operated ventilators must be provided because the supply of electricity or gas is unreliable. The simplest form of an effective fan to cool the shelter is a wide and heavy frame with a flap that swings in the shelter's doorstep and can be swung from the hinges on the ceiling.
The flippers open in one direction and close on the other, pumping air. (This is Kearny Air Pump, or KAP, named after its inventor Cresson Kearny.) Kearny asserted, based on field testing, that air filtration is not usually necessary in nuclear shelters. He asserts that the fall is large enough to fall to the ground, or so smooth that it will not settle and thus have little mass to emit radiation. However, if possible, shelters should have air filtration to stop chemical, biological and nuclear impurities that may be abundant after the explosion.
Vent opening in the bunker should be protected by blast valve. The blast valve is closed by a shock wave, but the reverse remains open. If the bunker is in a built-up area, it may include a water cooler or immersion tube and a breathing tube to protect the population from a fire storm. In this case, secondary exits are also most useful.
Bunkers should also protect the population from normal weather, including rain, summer and winter heat. The normal form of anti-rain is to place plastic film on the main structure of the bunker before burying it. Thick film (5-mil or 125 Ã,Âμm), cheap polyethylene works quite well, because the cover layer protects it from degradation by wind and sunlight. Typically, reinforced concrete shelters that are buried or underground usually have the normal appearance of a building.
When a house is built with an explosive shelter, its normal location is a bathroom beneath a level reinforced by a large closet. In apartment houses, shelters can double as storage space, as long as it can be emptied quickly for its primary usage. Shelter can be easily added in the construction of a new basement by taking an existing angle and adding two poured walls and ceiling.
Some vendors provide explosive shelters that are engineered to provide a good protection for each family at a modest cost. One common design approach uses fiber-reinforced plastic skin. Compressive protection can be provided with cheap earth arches. Overburden is designed to protect against radiation. To prevent the shelter from floating to the surface in the high groundwater, some designs have a skirt held with a cover layer. Properly installed and properly installed houses do not become a drain in the yard. In Switzerland, which requires shelters for private apartment blocks and large private homes, the lightest shelters are built of stainless steels.
Maps Blast shelter
Subway
During World War II, people in London and Moscow survived the German air bombings by taking shelter at subway stations, for example, the London Underground. In the second half of the 20th century, metro stations in Eastern Europe and the Soviet Union were built to serve as burial shelters.
Pyongyang Metro Station in North Korea, built 110 meters underground in the 1960s and 1970s, was designed as a nuclear explosion shelter and each station entrance has thick iron doors.
Further reading
- Protecting Buildings from Bomb Bombage: Transfer Blash-Effects Mitigation, 1995, pp32-33 literature review.
- FEMA Bibliography of building design documents to prevent explosion hazards.
- Blast Loading and Blast Effects on Structures - An Overview, 2007. Predicting blast pressure. AFSWC-TDR-6Z-138 Air Force Design Manual, Principles and practices for hardened structure design 1962. Replaced by Manual 1987 for Design and Analysis of Hardening Structures, AFWL-TR-87-57 and Army Technical Manual TM 5 -855-1 (Air Force AFPAM Pamphlets 32-1147, Naval Guidebook NAVFAC P-1080, DSWA Manual 1997).
See also
- Air raid shelter
- Autonomous building
- Emergency preparedness
- Backtrack (survivalisme)
References
External links
- Oregon Institute of Science and Medicine
- Era 60 Equipment ATT Nuclear Bomb Shelter. Hi-res interior & amp; virtual exterior tour
Source of the article : Wikipedia
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