Experimental Seismic Collapse Study of a Full-Scale, 4-Story, Soft-Story, Wood-Frame Building

AbstractIn the San Francisco Bay Area and throughout much of California, there are a large number of wood-frame buildings with garage space at ground level, resulting in open fronts on one or two sides. This type of geometry results in a soft and weak first story, and buildings of this archetype are generally referred to as soft-story buildings. During an earthquake, these buildings are susceptible to severe damage and collapse and have been recognized as a disaster-preparedness problem. The five-university Network for Earthquake Engineering Simulation (NEES)-Soft project culminated in a series of full-scale soft-story wood-frame building tests to validate two different retrofit philosophies and included a 2-month test program encompassing four different retrofits. The building had 370 m2 of living space and was designed to be generally representative of older San Francisco Marina and Mission District construction, circa 1950s. Following the retrofit testing, which only moderately damaged the test buildin...