- As one of the first buildings built in the Mission Bay area, the five-story, 165,000 s.f. Rock Hall incorporated several innovations balancing economy of construction with the seismic performance desired for an institutional client such as UCSF. The building is supported on a precast pile foundation through approximately 100 feet of bay mud deposits. By only connecting select pile caps with grade beams and designing the ground floor slab as two-way, the foundation concrete volume was reduced, excavation was reduced, and schedule time in constructing the slab was also shortened.
- UCSF expressed a need for good seismic performance to protect their investment in the building. On this project we worked directly with Nippon Steel in Japan to design and procure Buckling-Restrained Braces for the building. While this technology was brand new to California seismic engineering practice, we were able to get the new system approved, resulting in a building with better than average seismic performance for a cost comparable with the more standard bracing systems in use in the bay area at that time. Within a few years of this project the popularity of the BRBF system exploded resulting in local US fabricators beginning to make their own version of the BRB in the US. This system remains as one of the standard economical choices of seismic system for a steel building.
- As details for the seismic system were developed, we decided to design all the seismic connections as all-bolted instead of the more traditional method of field-welding all these joints. This innovation allowed the majority of welding to occur in the fabrication shop instead of the field, resulting in a two month savings in steel erection time which translated to an overall building schedule reduction as well. By doing a majority of the welding in the shop, the quality control of the welding is more uniform and allows for lower inspection costs for the owner in the shop and the field.
- The main atrium stair had long cantilevered spans which were susceptible to excessive vibrations causing a central column to be installed to reduce movement. The introduction of this column required that the connections of the stair to the floor line remain clamped under gravity loading, but release and slide under larger seismic drifts in the building. We designed a custom connection with brake pad material that allows this unique behavior to occur reliably.
As one of the first buildings built on the new UCSF Mission Bay campus, Rock Hall broke new ground in speed of construction and adoption of a then-new seismic technology from Japan. Customized Solution
- Architect: Pelli Clarke Pelli Architects/Flad Architects
- Owner: University of California, San Francisco
- Steel framed with buckling-restrained braced frames
- The BRB frames were connected with special hinging steel connections that limit damage in the frames and saved on construction cost