Light-gauge cold-formed steel (CFS) framed multi-story residential housing has the potential to support societies urgent need for low cost, multi-hazard resilient housing. CFS-framed structures offer lower installation and maintenance costs, are durable, ductile, lightweight, and manufactured from recycled materials. In addition, consistency in material behavior and low material costs are added benefits compared with their wood-framing counterparts. The components of CFS-framed assemblies (studs, track, joists) can be assembled quickly and with relative ease into prefabricated panels. Notably, the ductile nature of a CFS-framed structure aligns with the performance needs in moderate to high seismic zones. Compared to other lightweight framing solutions (such as timber), CFS is non-combustible, an important basic characteristic to prohibit fire spread. Taken in totality, these many beneficial attributes lead to a highly sustainable infrastructure for housing communities.
This research aims to evaluate the earthquake and post-earthquake fire performance of mid-rise CFS-building systems through full-scale earthquake and live thermal testing of a 6-story wall-braced system. Through partnership with cold-form steel and other materials suppliers, design engineers, and insurance entities, a unique experimental program is underway. Central to this effort is the construction of a full-scale portion of a 6-story CFS-wall braced building directly on the UCSD Large High Performance Outdoor Shake Table. Wall and floor systems for the building are assembled in a panelized fashion off-site, thus the overall erection time of the building is dramatically reduced. The test building will be subjected to low amplitude white noise motions and sequentially increasing in amplitude earthquake motions. Subsequently, live thermal tests will be conducted on two floors of the building, in corridor and room like spaces strategically designed to investigate thermal patterns that develop due to reduced compartmentation ensued during the earthquake motions.
[left] Tests by Yu (2014) on a similar steel sheathed CFS-framed wall adopted in this test program and [right] a 4-5 Story CFS-framed building in Union City, CA