Base Isolation

SGH employs base isolation to enable structures to withstand major earthquakes and remain functional. We use this technology in the design of new structures and in the retrofit of existing structures. Our innovative design solutions do not disrupt building occupants and improve the performance of the structure during an earthquake.


In a conventional design, earthquake forces are amplified by a factor of three to four at the top of the structure. In a base isolated design, the earthquake forces are reduced by a factor of three to five across the isolators, with no amplification of forces through the height of the structure resulting in factor of ten reduction in the forces at the top of a building. The benefits of base isolation are:

  • Provides a favorable cost-benefit ratio
  • Protects structures, contents, and business functions
  • Preserves historic structures when applied as a retrofit
  • Provides additional margin of safety for the standardized design of nuclear facilities
  • Protects nuclear structures against extreme events

SGH's base isolation services include:

  • Design or retrofit of buildings, bridges, nuclear facilities, and monuments
  • Feasibility studies
  • Peer review
  • Test program monitoring
  • Performance-based analyses of existing structures