http://www.ashdodsurf.com/earthquake-safety-9/
earthquake safety
How can studying the effects of earthquakes help engineers improve the safety of buildings?
10 points to most accurate answer
If you want more about earthquakes, check out chapter 3.3 from the Building and design Construction Handbook (reference below). Sorry, this is a little text heavy, but here are the some explanations:
Design of buildings for both normal and emergency conditions should always incorporateva safety factor against failure. The magnitude of the safety factor shouldvbe selected in accordance with the importance of a building, the extent of personal injury or property loss that may result if a failure occurs, and the degree of uncertainty as to the magnitude or nature of loads and the properties and behavior of building components.
As usually incorporated in building codes, a safety factor for quantifiable system variables is a number greater than unity. The factor may be applied in either of two ways.
One way is to relate the maximum permissible load, or demand, on a system under service conditions to design capacity. This system property is calculated by dividing by the safety factor the ultimate capacity, or capacity at failure, for sustaining that type of load. For example, suppose a structural member assigned a safety factor of 2 can carry 1000 lb before failure occurs. The service load then is 1000/2 _ 500 lb.
The second way in which codes apply safety factors is to relate the ultimate capacity of a system, to a design load. This load is calculated by multiplying the maximum load under service conditions by a safety factor, often referred to as a load factor. For example, suppose a structural member assigned a load factor of 2 is required to carry a service load of 500 lb. Then, the member should be designed to have a capacity for sustaining a design load of 500 _ 2 _ 1000 lb, without failing.
While both methods achieve the objective of providing reserve capacity against unexpected conditions, use of load factors offers the advantage of greater flexibility in design of a system for a combination of different loadings, because a different load factor can be assigned to each type of loading in accordance with probability of occurrence and effects of other uncertainties
Buildings should be designed to withstand minor earthquakes without damage, because they may occur almost everywhere. For major earthquakes, it may not be economical to prevent all damage but collapse should be precluded.
Because an earthquake and a high wind are not likely to occur simultaneously, building codes usually do not require that buildings be designed for a combination of large seismic and wind loads. Thus, designers may assume that the full strength of wind bracing is also available to resist drift caused by earthquakes.
The methods of protecting against high winds described in Art. 3.2.4 may also be used for protecting against earthquakes. Shaking of buildings produced by temblors, however, is likely to be much severer than that caused by winds. Consequently, additional precautions must be taken to protect against earthquakes. Because such protective measures will also be useful in resisting unexpectedly high winds, such as those from tornadoes, however, it is advisable to apply aseismic design principles to all buildings.
These principles require that collapse be avoided, oscillations of buildings damped, and damage to both structural and nonstructural components minimized. Nonstructural components are especially liable to damage from large drift. For example, walls are likely to be stiffer than structural framing and therefore subject to greater seismic forces. The walls, as a result, may crack or collapse. Also, they may interfere with planned actions of structural components and cause additional damage. Consequently, aseismic design of buildings should make allowance for large drift, for example, by providing gaps between adjoining buildings and between adjoining building components not required to be rigidly connected together and by permitting sliding of such components. Thus, partitions and windows should be free to move in their frames so that no damage will occur when an earthquake wracks the frames. Heavy elements in buildings, such as water tanks, should be firmly anchored to prevent them from damaging critical structural components. Displacement of gas hot water heaters is a common cause of gas fires following earthquakes.
| Account limit of 2098 requests per hour exceeded. |
Martha The Safety Gal Does Earthquake Safety
what safety measures we should take during earthquake?
Here ya go...
http://www.disastercenter.com/earthqk.htm
3 Comments
Been watching your website, as I am planning to walk some of Te Araroa towards the end of next year (depending how much time we can get off work).No reason for anyone to worry about you coming here in a month. There’s still the research saying that the “big one” (when the alpine fault next moves, which is on average every 300 years, and last occurred 300 years ago) is due. It’s expected to be much bigger than the 7.1 last weekend. But it also may not happen for another 300 years, and if you were to let small odds like that put you off, well you’d never do anything.As you say, the ongoing aftershocks are only damaging already-damaged buildings. And in a month they’ll be all but over. (One of our aftershocks that I recall was a 5.4. I lay in bed thinking about getting under the bed but decided it was not big enough a shake to warrant moving. The 7.1 however, was a real good ride. and the 5.1 aftershock on Wednesday morning centred in Chch was worrying because I was at work on the 3rd floor of a 6 floor building that is known not to meet earthquake safety standards!)
one word…toilet paper!
I'm assuming John then went to the hospital for the golf club sized dents in his head.