Seismic Retrofits

201 Post Street. Listed on the National Register of Historic Places. Steel framed building, added concrete moment frames.

201 Post Street. Listed on the National Register of Historic Places. Steel framed building, added concrete moment frames.

Seismic evaluation and rehabilitation of buildings

Forell/Elsesser has substantial experience in the seismic evaluation and rehabilitation of structures of all types of construction in the highest known seismic areas in the U.S. and elsewhere, including buildings, bridges, and piers. Our projects of this type include government, institutional, and privately-owned properties. Our completed seismic rehabilitation project experience includes some of the largest and most historically significant buildings in the U.S. to receive seismic retrofit work, including the City Halls of San Francisco, Oakland, Pasadena, and Berkeley, as well as the California Supreme Courts Building in San Francisco, the Utah State Capitol, the San Francisco Asian Art Museum, and the Salt Lake City & County Building. In addition, we designed the retrofits for the 1930’s era Ford Motor Plant in Richmond, California, and the Pacific Gas and Electric Company Headquarters Complex in San Francisco.

Seismic Upgrade Design Ability

Although all seismic rehabilitation projects have varying performance goals and priorities, they share some characteristics. They seek to minimize the adverse effect on the building’s function of the seismic upgrade and many seek to minimize disruption during construction.

UC Berkeley, Blum Center. Retrofit of historic wood building. Required temporary shoring to add new floor below and added BRBFs.

UC Berkeley, Blum Center. Retrofit of historic wood building. Required temporary shoring to add new floor below and added BRBFs.

All have technical goals that are described by seismic performance criteria. In order to meet a project budget, our approach is always to develop designs that are appropriate to the project seismic performance criteria. All of our seismic upgrade design projects are reviewed by a variety of review entities and agencies. Beyond the functional, economic and technical considerations, our projects all respond to the aesthetic qualities of the building. In some cases, such as with an historic building, this leads to a concealed structural system. In other cases, the new elements may be prominent and integrated with the building’s original design.

Technical Expertise

Forell/Elsesser has a reputation for use of ground-breaking innovations (seismic isolation, passive damping, and lightweight cable bracing) for the optimal performance-based seismic rehabilitation of historic structures. These techniques are applied when they are determined by comparison to be more economical than all other methods for the project. Forell/Elsesser conceived the world’s first use of seismic isolation for an existing building:  the Salt Lake City & County Building.

For more than 20 years, we have provided dynamic linear and non-linear static and dynamic response analyses for major seismic evaluation and upgrade projects including high rise buildings (Hiram W. Johnson State Office Building and the Wilshire Federal Building), and historic buildings in regions of high seismicity (Oakland City Hall Rehabilitation).

Baker Hamilton. Conversion and rehabilitation of historic URM and wood frame building. Shotcrete walls and steel braced frames added.

Baker Hamilton. Conversion and rehabilitation of historic URM and wood frame building. Shotcrete walls and steel braced frames added.