Seismic base isolation is a relatively new retrofitting technique that provides a structure flexibility to withstand the lateral forces during an earthquake. Isolators are comprised of two basic types, friction-pendulum and vulcanized lead-rubber, that act like large “motor mounts” when placed under a load-bearing column of a bridge or building. During a seismic event, the isolators absorb the impact thereby greatly reducing the seismic forces transmitted through the building.

As you can imagine, seismic isolators must be quite large and heavy in order to hold the immense loads imposed on them. Since Sheedy Drayage Co. has been moving large, heavy objects for over 75 years, it was only natural that the contractors of seismic base isolation projects would turn to Sheedy for help.

Specializing in seismic upgrades of existing contemporary and historical structures, Sheedy Drayage Co. has been instrumental on a number of key projects to include San Francisco’s City Hall, the largest structure in the world ever retrofitted with base isolators. Sheedy also installed the largest isolators in the world at the time on the Benicia-Martinez Bridge and now has more experience installing isolators, sliders, flat-jacks, and dampeners than any other company in the industry. In fact, many of the concepts for temporary shoring, column load transfer, and seismic dampening equipment installation are unique to Sheedy such as our specially designed friction griping technique. When it comes to seismic base isolation engineering and installation, Sheedy Drayage Co. remains the contractor of choice.

Communication and coordination is crucial if the seismic renovation project is to be completed on time and within budget. Sheedy’s project managers are experts at managing large, complex, and historical renovation projects and can help in coordination and scheduling process. In some cases, an entire structure can be isolated without interrupting daily operations.

What Sheedy can do for you:

• Complete column base isolator, slider, and flat-jack installation services
• Column isolation, temporary support, jacking system installation, and load transfer engineering
• Complete project management and engineering services performed directly by Sheedy Drayage Co. personnel.

List of major projects:

Pasadena City Hall
Pasadena, CA
Project completed in April 2007
238 friction-pendulum isolators installed
Column loads up to 450 tons

Oakland City Hall
Oakland, CA
Project complete in November 1994
113 isolators installed
Column loads up to 1,900 tons

Veterans Administration Medical Center
Long Beach, CA
Project completed in December 1995
128 vulcanized rubber isolators and 36 sliders installed
Column loads up to 740 tons

Kerckhoff Hall, U.C.L.A
Los Angeles, CA
Project completed in December 1995
128 isolators and 36 sliders
Column loads up to 281 tons

San Francisco City Hall
San Francisco, CA
Project completed in August 1997
530 isolators and 61 sliders installed
Multiple column loads up to 2500 tons total

Martin Luther King Civic Center
Berkeley, CA
Project completed in 2000
100 isolators installed
Column loads up to 600 tons

Benicia-Martinez Bridge
Martinez, CA
Project completed in June 2001
22 friction-pendulum isolators installed
Column loads in excess of 3,500 tons

Asian Art Museum
San Francisco, CA
Project completed in May 2002
196 rubberized isolators installed
Column loads up to 600 tons