FEMA P-807, Washington, D.C. : Federal Emergency management Agency (FEMA), Applied Technology Council (ATC), 2012-05, PDF
FEMA worked with ATC to develop these guidelines to address seismic retrofit requirements for weak-story wood-frame buildings in seismically active regions of the United States, with a particular focus on Northern and Southern California and the Pacific Northwest. The guidelines focus on multi-family, multi-story buildings with weak first stories, such as those damaged in the Marina District of San Francisco in the 1989 Loma Prieta earthquake, and apartment buildings with tuck-under parking, such as those damaged in Southern California in the 1994 Northridge earthquake. These seismic retrofitting guidelines are the first to focus solely on the weak first story and to provide just enough additional strength to protect the first floor from collapse but not so much as to drive earthquake forces into the upper stories, placing them at risk of collapse.
Available online: http://nisee.berkeley.edu/elibrary/files/documents/elib/www/documents/201303/fema-p807.pdf (20 MB)