Base isolation

See the main article: Earthquake engineering

Base isolation is a collection of a building’s units resting on its foundation to provide separation of the building from shaking ground thus improving seismic performance.

Shake-table testing of two building models at CSUN. The right one has a base isolation device.

Basic parts of base isolation system

Base isolation system consists of isolation units with or without isolation components, where:

1. Isolation units are the basic elements of base isolation system which provide the mentioned separation effect to a building structure.

2. Isolation components are the connections between isolation units and other parts of the building having no separation effect of their own.

Famous base-isolated buildings

• 
  Pasadena City Hall, California
• 
  San Francisco City Hall, California
• 
  Salt Lake City and County Building, Utah

History

From the very beginning, the theory of base isolation rested on two pillars: heavy damping and frequency separation. Unfortunately, nobody paid any attention that the heavy damping was a sort of a strong connection between a substructure and superstructure, and that the idea of decoupling them with the help of such connections was of no good. Anyway, to virtually test-drive any design concept of base isolation, some online help is available now.