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Earthquake Safe Construction Tips and Guidelines

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  • By constructing houses and public buildings safe, 80% to 90% of loss can be reduced. Because
    Disaster risk = Hazard * Vulnerability.
  • If Vulnerability is reduced, risk of disaster will decrease.
  • Prediction of earthquake only saves human losses not economic losses due to collapse.
  • Most of earthquake occurs in ocean.
  • Earthquake of Magnitude 6 evolves energy that is equal to 1 Hiroshima atomic bomb.
  • Magnitude 7 ==> 100x Energy evolved = 1 Hiroshima atomic bomb.
  • Magnitude 8 ==> 100 x 100 Hiroshima atomic bomb.
  • Earth is not consistent but its made up of plates.
    • Each moves independently.
    • Plates are called tectonic plates.
    • Earthquake occur due to movement of tectonic plates and their head on collision.

Focus:

  • Deep in earth crust. 5 to 6 - 70 to 80 km depth.
  • More depth, less will be disaster as more is absorbed inside.
  • Projection of focus on earth surface is called epicentre.
  • Equivalent Energy is transferred through waves causing vibrations in structure.
  • Foundation also moves to and fro. If foundation is made stable, structure will be safe. For example if beams are provided on foundation and structure moves on the beams.
  • Walls and Columns are the most important by Earthquake point of view.
  • About 1500 tones of steel can be saved in a 60 storey building due to only one level difference of seismic zone.
  • 90% of economy losses and 90% of human losses are due to the collapse of buildings.
  • Earthquake resistant building is one which does not collapse even if it has irreparable cracks.

Design span of buildings

  • Nuclear power plants-> 2500 years.
  • Dams and Bridges-> 500 years.
  • Houses-> 50 years.
  • Not even small cracks should occur in Nuclear power plants because implications are very high i:e, life safety levels are not common in each type of structure.
  • 2% of total cost can save a building from earthquake.

Dhajji: Timber frames and bracing. To make earthquake resistant mortar take 1 bag of cement + 3 wheel barrows of sand. The mortar should be used within 1 hr.

  • Rectangular or square shaped buildings are good in earthquake resistance.
  • Building openings should be well distributed and less.
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