Forell | Elsesser served as Engineer of Record for the 180,000 s.f. adaptive re-use and seismic isolation retrofit of the City of San Francisco’s Old Main Library into a world-class Asian Art Museum. Built in 1917 in the Beaux-Arts style, the building is one of the City’s most important historic structures and was adapted to retain the beauty of its architectural character. The building structure is steel framed with masonry walls. This museum houses the largest non-property asset in the City of San Francisco with an estimated value of $5 billion.Customized Solution
- The seismic upgrade scheme involved base isolation with the stiffening of the superstructure through the addition of concrete shear walls to protect the museum’s irreplaceable collection of Asian art and artifacts, including immensely valuable, brittle Ming Dynasty vases.
- The base isolation bearings were placed over a reinforced foundation system below the current slab on grade. A new suspended basement floor was constructed above the isolation bearings. Reinforced concrete shear walls were constructed from the top of the basement floor to the roof level to provide a complete and rigid lateral load path for all sections of the building. Floor diaphragm reinforcement and collector lines were used to tie the existing and new floors into the new shear walls.