Santa Ana State Office Building

Santa Ana, California

This nine story concrete frame office building, originally constructed in 1972, was investigated as part of the State of California’s State Seismic Program. Due to unfavorable beam versus column geometry and the lack of interior joint reinforcing, it was determined that under a relatively low level seismic force that the frames would suffer joint yield and failure. Four distinctly different seismic retrofit strategies were investigated, with the exterior concrete buttress shear wall scheme selected, as it provides sufficient stiffness to protect the existing frame joints, while minimizing the disruption to occupants. The building was featured as a case study in the Fourth Conference on Tall Buildings in Seismic Regions.