Structural performances of two historic high-rise buildings, constructed in the early 1920s and located in seismic zone 3 in downtown Sacramento, CA were investigated. The objectives of this evaluation were to determine whether these structures met the current seismic criteria and to propose strategies to upgrade such performance to an acceptable level. Both structures, have fourteen main floors, are 200 ft tall, have an approximate floor area of 90,000-ft2. Performance-based procedures based on the Life Safety (LS) provisions of FEMA 356 for the Deign Basis earthquake (DBE). Detailed three-dimensional mathematical models of the structures were prepared. Both structures performed better than expected when subject to seismic loading. A voluntary seismic upgrade using fluid viscous dampers (FVDs) and steel struts was utilized for one structure, whereas, for the second structure, structural modifications were undertaken to address some of the occupancy needs.
Amir S.J. Gilani, Miyamoto International, Inc., West Sacramento, CA
H. Kit Miyamoto, Miyamoto International, Inc. West Sacramento, CA