Base Isolation

Pioneers since the early 1980s

Forell/Elsesser pioneered the use of seismic base isolation in the early 1980s.  Over the past 30 years we have gathered immense experience in the performance, behavior and details of isolation systems, and a high level of expertise from hands-on project design and development.  We have provided base isolation feasibility studies, upgrade concepts and complete designs for more than 30 buildings including the first base isolated existing building retrofit in the world (Salt Lake City and County Building), the tallest building (Oakland City Hall, at the time of construction), the largest existing building (San Francisco City Hall; at the time of construction), and the first seismically isolated aqueduct in the U.S. (Mokelumne Aqueduct #3, Sacramento River Delta, California).

Seismic isolation is the “separation” of the building from the ground, severing the rigid structure-to-ground contact with a mechanical device usually located between the structure and the foundation.  The isolator is designed to relieve most of the destructive earthquake movement, thus protecting the building.  Our base isolation portfolio includes: