Earthquake Hazards: Building Design and Construction, and Liquefaction

Building Design and Construction

  • strength and flexibility of materials and design
    • wood houses are generally very safe
  • size/proportions of the building
    • single-family homes generally have a low and squat geometry
  • however, if you shake long enough, or is the building is on soft ground, even a wood-framed building will fail
    • this often means the building fell off its foundation

Liquefaction

  • shaking causes unconsolidated soils and sediments to liquify
  • ground loses cohesion and flows
  • buildings fall down, can remain intact
  • soil/sediment grains are touching in many places
  • little space between grains so the ground is strong
  • vibrations wiggle the grains, resulting in an increase in water pressure
  • space between grains increases
    • grains can move easily so water can flow
  • as soon as shaking stops, water pressure decreases
    • grains touch and soil becomes firm again

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