- Forell/Elsesser designed the seismic retrofit for this 160,000 s.f. 18-story historic City Hall building constructed in 1913. The structure was damaged in the 1989 Loma Prieta earthquake.
- Base isolation was used at the base, with a combination of concrete shear walls and braced frames above.
- The project required the transfer of large column loads of 4 million pounds onto the seismic isolator bearings.
- The seismic retrofit elements are completely hidden within the existing historic envelope.
Oakland City Hall was the first ever high rise seismic retrofit using seismic base isolation. Customized Solutions