Seismic Strengthening of University Hall, Berkeley, California

University Hall, on the Berkeley campus of the University of California is a seven-story plus basement reinforced concrete office building. It had been identified in the late 1970s as a building with poor potential seismic performance. Various strengthening options were evaluated and construction costs were estimated in 1988. The 1989 Loma Prieta earthquake caused only minor cracking in several non-structural partitions. Following the 1989 earthquake, the University provided fund for seismic retrofits projects, and University Hall was one project included in that program. A study was performed to determine schematic strengthening solutions. First was an interior scheme which added new interior reinforced concrete shear walls. The second scheme consisted of adding partitions of concrete pier or wall on each side of the windows to create an exterior facade of shear wall with regular openings. The third solution consisted of adding external steel diagonal bracing. The University selected the steel diagonal bracing solution.