Saiful Bouquet was retained to perform seismic evaluation and develop appropriate strengthening scheme for the Birnkrant Student Residence at USC. The structure was damaged in the Northridge Earthquake, and modifications were desired to mitigate existing building seismic hazards.
The dormitory is configured with a classic linear floor plan, with a longitudinal concrete shear wall along one side of the central corridor and perimeter frames with short columns and deep spandrel beams. Individual stacking shear walls along the central corridor are interconnected by shallow link beams with non-ductile reinforcing. Due to the expected high damageability of these link beam, analyses indicated a substantial percentage of the seismic forces were resisted by the perimeter frames. State-of-the-art modeling and seismic analysis techniques were used to predict damage levels in the perimeter frames, which were found to highly susceptible to damage in the event of a major ground shaking.
Prior engineering studies by another firm had attempted to address the issue of the weak perimeter frames by introducing a costly exterior shear wall or braced frame system. SB worked with USC. to instead modify the interior shear walls, thus off-loading the perimeter frames. It was necessary to infill door openings in a staggered pattern over three levels to strengthen the wall and protect the weak link beams and perimeter frames. The University was able to convert the existing double dorm rooms into quads to facilitate the work for substantial cost savings.
“…Saiful/Bouquet has been able to develop innovative and cost effective solutions during the development of a scope of a project, as well as produce properly detailed construction documents. In addition, Saiful/Bouquet has been very responsive to issues which arise during construction…”
– Steve Lohr, Formerly Project Director,
University of Southern California