Earthquake: Frequently
Asked Questions
|
What is an earthquake, and how does it effect buildings?
Is it possible to build "Earthquake proof" houses?
It is a misconception commonly shared that, houses could
be made earthquake proof. The reality however is that by taking precautions, the
earthquake resistance of the house can be increased finitely, making them
capable to resist quakes of specific magnitudes. These houses, too, may fail
once they face quakes of higher intensity than they are designed for.
How strong should buildings be made?
The purpose of earthquake resistant design is not to
prevent all damage by a severe earthquake, for such an objective would result in
unreasonably expensive structures. The first aim is to ensure against the loss
of life or injury. Second step is to balance the cost of additional design
strength against the probable cost of repair of damage over the expected life of
the structure.
As money is a limited resource, the main objective should be to prevent collapse of building with consequent loss of life. One must expect buildings to crack and to need repair if there is a major earthquake.
Secondly, community buildings like schools, hospitals, power stations etc are more important than individual houses. Hence these buildings should be built more strongly than ordinary houses.
What are the important considerations in making a house more earthquake
resistant?
(a) Reduce its mass and make it as light as possible
(b) The structures should be rigid enough, making sure that whole structure vibrates together as one unit. Schematically, in such units, the top portions are so joined to the bottom that all movements are transferred immediately from lower levels to the entire building and entire unit vibrates as one rigid body. Consequently, no disharmonious stresses are set up and structure remains safe. One way of doing so is by "tying" the structure using horizontal bands at plinth, cill, Lintel and roof level. Vertical reinforcement also makes structure more resistant.
International Conference on EcoMaterials announces "Ecomaterials for disaster prevention and Relief"in Quality Control and Assurance in Concrete Constructions 24 th – 27th September, 2001Main Themes Materials, products and components for construction |
The organising Institutions are: CIEDM (Center for the Research and Development of Structures and Materials) ISP JAE (Polytechnic Institute "Jose A. Echevarria") & EcoSouth For more informaiton contact: Tel/Fax: ++53 422 81539; Email: F.Martirena@ip.etecsa.cu ecosur@nicanet.com.ni |