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The objective of this survey was to provide data to emergency managers in Santa Clara County on the number of soft first-story multifamily dwellings (MFD) located in their communities using a cost-effective town-gown partnership. Target areas of cities were found by identifying areas containing residential units of two or more stories that had four or more living units. The survey found that 2,630, or 36%, of the 7,391 MFD in Santa Clara County are of the soft first-story construction type. It was found that one out of every nine apartment units in Santa Clara County is located in a soft first-story building. It is estimated that approximately 83,000 persons could be affected in the event of a severe earthquake. Emergency managers were given maps indicating areas of high-, medium-, and low-volume clusters of soft first-story MFD in each city. Follow-up interviews found that the communities that contain 67% of the identified soft-story MFD are using the survey information in their post-earthquake planning.


Vukazich, S., G. Selvaduray, and J. Tran, 2006. Santa Clara County Soft First Story Multi Unit Building Survey, Earthquake Spectra 22, 1063–1079. Reproduced with permission of the Earthquake Engineering Research Institute.