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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